Difference between Counterbore and Countersink

The goal of both counterbores and countersinks is to enable the head of a screw or other fastener to rest flush with or slightly below the surface of the material they are placed into. The angle at which the bigger hole is drilled separates them from one another. A counterbore is drilled straight into the material, leaving a level bottom between it and the narrower inner shaft, while a countersink’s bigger hole tapers at an angle.

Counter Bore

Except for a handful, the information required for each class is nearly the same. Since a counterbore is always drilled straight down without a taper, the angle is not necessary to know.

Countersink

We need to know the intended angle because a countersink is not drilled straight into the material. For those who are interested in mathematics, you have probably noticed that the angle and the major hole diameter make a triangle. The angle, major, and main diameters dictate the depth to which the countersink will be drilled, yet stating your anticipated depth is a useful way to verify your expectations.

Which way around is the sink on the board? Above or Below?
Is plating or not plating appropriate for the hole walls?
The hole’s small inner shaft’s completed diameter. (First Drill)
Major Diameter: the hole’s final surface diameter
The tapered drill’s angle.
Depth at which the countersink should be drilled.

Important Distinctions Between Counterbore and Countersink Holes

Although hardware can be positioned flush on the board surface with both hole types, there are some significant variations that affect how they are used:

1. Shape of a Hole

The form of the hole is the main distinction. Counterbores have straight cylindrical walls, whereas countersinks have conical shapes. This affects the fastener’s flushness against the board.

2. Size of Top Opening

In a similar vein, the two holes differ in the size of the top opening. A countersink’s top taper gradually from the entire hole width. A counterbore is matched in diameter to the fastener and has a broader concentric cut on top.

3. Walls That Are Vertical

Counterbores have vertical walls, and countersinks have inclined side walls. Fasteners have greater shear strength when the walls are vertical.

4. Width of Bottom Opening

A counterbore’s bottom hole aperture is larger than a countersink’s of equivalent size. This increases the design’s versatility in terms of fastener size selection.

5. Material Elimination

In order to make a countersink, more material is removed from the PCB. Counterbores preserve the strength and substance of PCBs.

When to Use PCB Counterbore and Countersink?

Now that we have a fundamental understanding of counterbore and countersink holes, let’s examine their applications in printed circuit boards. These fittings can be used on a printed circuit board, even though they are typically meant for stronger materials like metal and wood. A PCB has holes, just as most circuit boards, and how each hole is drilled counts.
There are screw holes in some of these holes that are utilized to attach the PCB to an application.
The sort of screw you can use to drill countersunk or counterbore holes into the PCB depends on what kind of screw is available. Instead of saving space or choosing a smoother design, use counterbore holes if you need a more stable PCB installation. The screws from them will provide a more stable attachment because these holes are typically big enough to fit socket fixtures. However, if you’re looking to save space, opt for a countersink hole.

For PCBs, which is better?

Knowing the main distinctions between counterbore and countersink holes is essential to determining when to utilize one over the other during PCB assembly.

The substance you’re drilling into frequently determines which technique you should use. As previously noted, countersinking is frequently recommended when working with wood to prevent overtightened screws from damaging the material.

Most manufacturers will utilize the counterbore approach instead of countersinking during PCB assembly to prevent needless damage to the PCB since countersinking necessitates using an angle and additional depth from the drill. Additionally, countersinking necessitates greater tools and materials, which could prolong the production process and endanger the board.

A ground or earth terminal, which is essentially a physical connection to the earth and serves as a secure return point to drain excess current, can be used to establish a connection through counterboring. Counterbore holes are also the finest option if you need to mount your PCB more securely. The screws from them will provide a more stable attachment because these holes are typically big enough to fit socket fixtures.

Principal Uses for Each Type of Hole

Countersink and counterbore holes have distinct uses because of their characteristics.

Typical Applications for Countersunk Holes
Installing flush screws on PCBs’ outside surfaces
Allowing low-profile bolt heads that must be flush with the surface of the board
Creating a sleek surface for aerodynamics on exposed external PCB layers
PCB mounting on thin aluminium covers or panels

Usage of Counterbored Holes in Common:

Fasteners for mounting machines that require a high shear strength
Letting spacers or washers rest flush against the PCB surface
Allowing bigger fastener heads to be accommodated with less material removal
Supplying the highest strength possible for screw connections at heavy load
Properly assembling internal PCB layers while reducing surface defects

Counterbores offer stronger screw joints, especially for internal PCB layers that are hidden, but countersinks are often better for applications where aerodynamics and aesthetics are important considerations.

Design Factors to Consider When Choosing a Hole Type

Engineers should consider the following aspects when designing a PCB layout and choose between countersunk and counterbored holes:

Sizes of Fasteners

More fastener heads can be used in counterbores than in countersinks of the same size.

Board Space Available

Because of their tapering design, countersinks require extra space.

Location of the PCB Layer

Counterbores work better for internal layers, whereas countersinks maximize outward layers.

Requires Shear Strength

Compared to countersunk holes, counterbores offer stronger screw joints.

Exposure to Environment

For external PCBs, countersunk holes enhance weatherproofing.

Priorities for Aesthetics

The surface finish is smoother with countersunk holes. It will be easier to guarantee that the hole type chosen offers the appropriate functionality for the application if these factors are considered early in the design process.

Drilling and completing Compare Counterbored vs. Countersunk Holes

A functional, dependable PCB requires appropriate drilling and finishing procedures after the hole type has been chosen. The following are some recommended procedures:

Cutting Countersink Holes

Use a countersink drill bit that is specifically designed for the screw size. The correct angled hole cannot be created with standard twist bits.
To prevent breaking through the bottom layer or tapering too shallowly, precisely adjust the drilling depth.
When you get close to the bottom, don’t push too hard to prevent drill walking. Reposition and back off if there is a walk.

How Counterbores Are Drilled

A normal straight hole should be drilled first using a twist bit with a minor diameter.
Next, cut the shallow counterbore ledge to the required depth using a bigger bit.
When counterboring, support the board with a stiff backer to avoid a tear-out.

Finishing Holes

After drilling, gently deburr the margins of both types of holes to prevent solder mask damage. Further polishing of countersinks with abrasive cones may be necessary to enhance fastener fit.

Proper drilling and finishing will result in smooth holes sized exactly right for the specified fasteners. This eliminates screw damage during assembly and offers reliable performance.

How to take dimensions for a Counterbore and Countersink

To account for the head of the flathead fixtures—which may be bolts, rivets, screws, or other similar objects—the angular sides of a countersink are recessed.

When drawing, the diameter, depth, and included rise of a counter-drilled hole are also provided, together with the surface diameter and angle. The head of the fastener can rest in the recessed area of the counterbore’s flat-bottomed, cylindrical section. When drawing and dimensioning this, the diameter, depth, and corner radius are provided and specified. In certain cases, the center can be substituted for the remaining shaft’s thickness when determining dimensions. Either a rectangular or polar coordinate form could be used to size both holes.

Conclusion

To attach to various materials, counterbore and countersink holes are used with matching screws. It is possible, albeit uncommon, to use this as a print circuit board fixture. As we’ve seen, a counterbore is more cylindrical than a countersink, which is a hole with a cone form. This article has emphasized the distinctions between a counterbore and a countersink, as well as the parallels between them, their definitions, and how both holes function. Since the terms counterbore and countersinks can be used interchangeably, they refer to the same kind of screws that fit into both a counterbore and a countersunk hole. Additionally, we have seen how they differ in their manufacturing process by employing distinct drill bits for every kind of hole.

Why Us?

PCB Runner offers a proposed array based on the individual board requirements; we make it less hassle for the layout designer to step & repeat the PCB and supply us with panelized Gerber. Submit your Gerber files at https://www.pcbrunner.com/free-pcb-quote/ or do reach out to our team offline at engineering@pcbrunner.com or sales@pcbrunner.com for your current or upcoming project’s needs.

FAQs

What minimum angle do we need to maintain for Countersink?

The hardware being used determines the countersink’s angle. Although it doesn’t have to match precisely, the hardware should have at least 50% contact with the countersunk hole. For hardware that is metric, the usual countersink angle is 90°, and for hardware that is imperial, it is 82°. We provide both perspectives in our sizes.

Can counter holes be plated for ground connections?

Plated is the best option if the screw is used to ground the board (such as PC motherboards) since it has numerous tiny vias radially surrounding the hole and the top, bottom, and internal ground plane connected together. The vias don’t have any heat relief. The vias make sure that the top and bottom pads are firmly attached to the ground plane, even in the event that the screw thread damages the hole plating. If not, it isn’t really important.

Does it cost extra in manufacturing?

However, as Scott Seidman points out, it can increase the cost of the board if there aren’t any other unplated holes in it. The type of lock washer or screw you put on the PCB may depend on whether or not there is a pad and how the pad is finished after assembly because solder has a propensity to flow cold. If the board is multilayer, there should be a lot of space between unplated holes and non-connected internal planes because you don’t want the screw shorting to (say) an internal power plane and the thread can damage the internal surface (people sometimes drill out holes that don’t quite match the mating surface).

Solving Common Issues in Edge Plating PCBs Tips and Tricks

Edge Plating:

In the PCB industry, edge plating is also referred to as metalized edge plating, border plating, plated contour, side plating, and castellation. The PCB board’s edges are encapsulated by the electroplating coating, which extends from the top to the bottom surface. PCBs can have their single-axis or multi-axis edges plated. Frequently used to enhance chassis grounding for signals and EMI shielding for high-frequency designs.

Purpose of Edge Plating:

Using PCB plating, printed circuit boards can be better protected against a number of vulnerabilities. The edge plating can assist in the following four primary areas:

1. Signal and power integrity:

The board’s power and signal integrity will both be enhanced by EMI reduction. High-speed electronics will benefit from extra shielding and better current-carrying capabilities due to the expanded grounding provided by the edge plating.

2. Electromagnetic adaptability:

The current flowing between the ground and power planes on multilayer circuit boards may cause electromagnetic interference (EMI) at their edges. The circuit board may surpass the EMC criteria it is designed to fulfill as a result of this interference’s potential to radiate outside of the system. The metal plating barrier that surrounds the board’s edges stops the electromagnetic interference (EMI) from radiating.

3. Thermal dissipation:

As signal rates rise, circuit boards have the potential to produce significant amounts of heat. In order to transfer this heat uniformly throughout the board, thermal vias are usually used to route it into an internal ground plane. Heat can easily escape the board through the metal edge since the ground plane is attached to the edge plating.

4. Structural reliability:

A circuit board’s strength and stiffness are reinforced by the addition of metal on its sides. Regular use reduces the likelihood of physical damage to the boards. Additionally, the PCB’s metal sides offer superior support when sliding the board into the intended electronic systems’ metal frames and casings. Additionally, edge plating will shield the PCB from unintentional physical harm while handling or use.

PCB Edge Plating Layout Guidelines

A few factors the designer should be aware of. A metal strip on the surface layers is first needed for the plating to bond with. In order to leave the metal strips exposed for plating, the designer must not only mention them in the layout data but also remove the solder mask from that region. Arranging the internal plane layers’ configuration is a crucial aspect of design.

It is necessary to move the power plane’s boundary away from the board’s edge, even though the ground plane is often attached to the edge plating. Any possibility that the power plane will make contact with the PCB edge plating during manufacturing and result in a direct power-to-ground short will be eliminated by pulling back the power plane boundaries.

The manufacturing drawings are the means by which PCB designers convey their intention for the edge plating. The sides of the board that must be plated, how the edge plating overlaps with the metal strips on the surface layers and the kind of plating and surface finishes needed must all be specified in the documents. A reputable PCB manufacturer can assist you in making these choices.

PCB Edge Plating DFM Guidelines

Alongside the common board plating procedures, edge plating—also referred to as rout plating—occurs to denote the partial or total depanelization that takes place prior to the metallization process. This is less of an issue in single-edge plating, although partially routed boards may still include tabs in the panel that serves as just fasteners connecting the routed edges to the panel as a whole. Depending on when depanelization is to take place, these tabs must strike a compromise between ease of removal and durability because they are only meant to be temporary throughout production operations.

The following are some main points that should be kept in consideration while doing DFM of plating

The thickest point of the tabs between the board and panel should be about 2.5 mm or 100 mils. For better adhesion, the tabs on the substrate will be thicker.
To avoid exposure during de-tabbing, artwork surrounding the tabs on both the outer and inner layers should be free of metal. Set a minimum as your goal. There is a 25mm/10 mil gap between the copper layer features and the tabs.
Tabs may be solid for removal after manufacturing, or they may have mouse bites for a less rigorous breakup after assembly.
Generally, tabs are placed every 50 mm or 2 inches along routed edges; however, more frequent placement may be necessary for extremely thick or thin panels or those with less mechanically robust substrates.
The edge plating will wrap around the routed edge to the other side of the board for optimal adhesion. The edge plating needs to be at least 0.4 mm/15 mils beyond the edge, with a gap of 2.5 mm/100 mils between it and any other plated edges and a clearance of 0.25 mm/10 mil to any other net copper features.
Although edge plating is usually continuous, it can be purposefully interrupted using tabs or by routing off plating. For connectivity with any exterior pours or same-net plane layers, the plating needs lastly be assigned to a net, usually ground.

Key points to handle the process of Edge Plating:

To guarantee successful plating and prevent possible problems, the edge plating procedure requires cautious handling and close attention to detail. The following are a few key components of the procedure:

1. Managing and Handling:

The PCB edge must be handled and prepared properly before it can be plated. Cleaning the edge to get rid of any impurities or residues that can impede the plating process is part of this. To guarantee that only the designated regions are plated, the edge must also be appropriately coated or protected.

2. Specialized Tools and Capabilities:

Specialized tools, including plating tanks or machines, along with experienced operators who are familiar with the relevant plating processes, are needed for the plating process to be carried out correctly.

3. Precautionary measures for Burrs:

The formation of burrs during plating is one of the main issues. Unwanted metal bulges called burrs can happen during the plating process and cause short circuits or other electrical problems. In order to avoid burrs and guarantee the PCB’s dependability, proper process control is necessary. This includes choosing the right plating parameters and applying deburring methods.

4. Adhesion with Plating:

For the PCB to be firmly attached for the lifetime of the board, the edge must have high adhesion with the plating material. The bond between the edge and the plating material can be strengthened by adhesion-promoting methods such surface roughening or the use of adhesion-promoting chemicals.

5. Controlled Soldering:

Soldering may occasionally be required during the plating procedure. The interlayer through-hole connections must be carefully controlled during the soldering process to avoid damage. The inside layers of the PCB may sustain damage from solder wicking, which can be caused by overheating or using incorrect soldering procedures.

The edge plating process can be effectively completed, producing dependable and long-lasting edge plating that satisfies PCB design criteria by closely monitoring these factors and putting the right safeguards in place. The danger of problems and failures is reduced by careful handling, preparation, and process control, which assist in guaranteeing the quality and integrity of the plated edges.

Safeguarding PCBs During Shipping: Best Practices for Manufacturers

PCB Runner understands the money, effort, and resources invested into creating your products. You should protect that investment if printed circuit boards are a necessary component of what you sell.

Although printed circuit boards are made of resilient components, as they seem to be, they are also expertly assembled. A single bump or crash could cause a critical circuit component to come loose. Your product will not function properly if your printed circuit board is broken.

To avoid this, you should talk to your manufacturer about PCB packaging and shipping procedures. Make sure your printed circuit board is adequately safeguarded. After all, not every harm is apparent, yet it still has the potential to reduce output.

Why it is Important to Pay Attention to Safe Shipping?

Being fixated on something like your printed circuit board’s packaging may seem absurd. Ultimately, what’s the big issue if it arrives undamaged and functional?

Think back to the time and work you invested in creating your circuit board. The printed circuit board is safeguarded by the packaging that it is transported in. Additionally, it will make sure it arrives securely. You have, after all, taken a great deal of time to design a circuit board that will operate safely in its intended environment. Protecting your work during shipping can be achieved by taking the time to make sure the packing will keep your printed circuit board safe.

In addition to the obvious risks of dropping and crushing printed circuit boards, other mechanical damage can also happen during shipping. Extreme temperatures can cause boards to deteriorate and solder to creep and crack. Someone who shakes boxes violently to see what’s inside, like myself, could be assigned to handle the parcels.

The same sources of harm you shield PCBs from, but less evident ones, include moisture and electrostatic shock. Any, all, or none of the following types of circuit board damage could occur to your boards during delivery. All that matters is how aggressively I shake the box and how skillfully they’re guarded.

Types of Packaging

Depending on your PCB assembly and what you need to protect against, different packaging is used. Having some background information is beneficial because it’s not always clear from the wrapping alone whether there is protection.

So, it is clear from the analysis that the following are the contributing factors that have a direct impact on PCBs.

Static Shock

Crushing/ Dropping/ Shaking

Temperature

Moisture

Depending upon PCBs need to choose the best practices for Safeguarding PCBs During Shipping.

PCB Runner provides all types of packaging services according to the demand of the customer or according to the need of PCB protection.

1. Anti-static PCB Packaging

Using specialized PCB packing materials is essential to keeping PCBs safe in transport. For example, an anti-static bag is always required for PCBs, whether or not they have a battery, to guard against short circuits and battery damage. Use non-static dividers to keep numerous PCBs apart while packaging them for shipping. By taking this extra precaution, you can lessen the chance that the PCBs will rub against one another and cause scratches or other damage.

1. Anti-static bags:

These can be distinguished from ordinary anti-static bags or dissipative anti-static bags by their shining metallic coating, which frequently has a Ziploc-style closure. These actively guard against charges, making them ideal for long-term storage, shipment, and handling. They are, therefore, also referred to as shielding bags. Consequently, the materials inside are essential for shielding bare components like MOSFETs from external charges and are successfully insulated from them.

2. Pink poly bags:

Pink poly bags typically satisfy MIL-PRF-81705 and other industry standards for electrostatic discharge prevention materials. The distinctive pink color of the bags meant for ESD protection makes them easy to identify and ensures safe handling and application in areas where electrical components are housed.

3. Antistatic Padded Boxes:

Except in cases where the assembly is extremely large, these boxes are rarely utilized. A good example is the network switches, which sometimes have a very large modular connector that extends over the other parts of the board. These boards are significantly better supported by a padded box than by a basic antistatic bag. Customers can also benefit from these since they are reusable and suitable for long-term storage.

4. Conductive anti-static bags:

ESD Warning Stickers: It is standard to apply an ESD warning sticker to a device’s packaging after it has been placed in an antistatic bag. An ESD warning sticker can be used to seal a package containing electronic equipment that has been placed in an antistatic bag and does not require vacuum sealing. Additionally, these stickers come in rolls and in a range of styles.

PCB Runner deals in specialized anti-static packaging per customer demand and requirement.

2. Moisture-proof PCB Packaging

The electronic parts of the PCB may suffer damage from atmospheric moisture in a variety of ways. For instance, a short circuit could occur if a little water drop unintentionally travels across the circuit board’s trace. Alternatively, dampness can cause electronic equipment to corrode the circuit board’s traces.

One of the most frequent reasons that PCBs degrade in outdoor settings is moisture. Although your board will probably be protected from the elements in the field by an appropriate waterproof casing, the boards may still come into contact with moisture during shipping. Moisture can have a detrimental effect on even bare PCB boards. Consider the packaging’s ability to cope with moisture if your PCBs will be traveling by sea over extended periods of time or through humid environments.

Sealed moisture barrier bag with a little bag of desiccant:

PCBs will be separately packaged, most likely with a little packet of desiccant, to keep out moisture in the air. Additionally, typically resistant to punctures, moisture barrier packaging provides your boards with an additional layer of protection.

Vacuum sealed:

You can have all the air removed from the packaging surrounding your PCB if you’re using it for a really moisture-sensitive circuit board application. It seems to me like a more organized form of shrink wrap. If you require protection on several fronts, vacuum-sealed ESD packaging is another option.

3. Anti-Vibration PCB Packaging

If insufficient anti-vibration packing is used, PCBs may be susceptible to shock or flex damage as a result of possible rough handling during transport. This may cause a PCB to flex or shock. Enough cushioning should be provided to limit movement inside the outer packaging and shield exposed pins and other vulnerable places to avoid that from happening.

The following categories can be used to separate packaging technology:

1. Tissue paper and bubble wrap:

Unless you’re shipping bare PCBs (which just have a rubber band holding them together), this is probably the most basic packaging you’ll see. This is fine for very simple, robust boards, but if you have more sensitive components, you probably want to step it up.

2. Compressed packaging:

Tough materials should be used to pack fragile things so that any impact or vibration energy can be absorbed and directed toward the strongest component of the contents. When an elastic material is shock-proof, it has the capacity to effectively distribute external force, absorb energy, and safeguard the contents.

3. Floating packaging:

In essence, it is similar to the compression packaging technique. The elastic material utilized is a small pad that has the ability to move and flow, which makes it different from other materials. This allows it to efficiently fill the gap left by the immediately stressed component and distribute the impact of the contents.

4. Mold box packaging:

In order to package the products and create the shockproof effect, Pcb manufacturers use the model to create a mold box out of the material that has the same shape as the product. Small, light products are packaged using this strategy most often.

5. Wrap package:

One piece of product is wrapped in several kinds of sheets and placed inside the outermost packaging box. For the packaging of small items, this technique is used to prevent products from being exposed to intense shock.

When shipping PCBs, PCB Runner complies with client needs and the above-described conditions by employing best practices. You can rely on us to handle your Pcbs from design to shipping with reliable, secure, and timely delivery since we take care to ensure that moisture, temperature, shock, and static charge do not affect them.

We take great care in packaging and ensure that the product will arrive at its destination undamaged and in perfect condition.

The Ultimate Guide to Designing Castellation PCBs for IoT Devices

What are Castellation PCBs?

A particular type of PCB design is known as a castellation PCB (Printed Circuit Board), which has small plated half-holes or notches around the board’s edges. These holes are known as castellation holes, which make it simpler to solder the board and join the PCB to other panels or sections. In surface mount technology (SMT) applications, where components are put directly onto the board’s surface, Castellation PCBs are frequently utilized. This is a typical method for assembling PCBs.

What are Castellated Holes?

Castellated holes are used for setting up an electrical and mechanical connection between two different PCBs or between a PCB and another module. Castellated holes are shaped like a castle’s battlements, with notches or teeth running along their edges. They are placed on a PCB’s edges. It is simpler to solder the PCB straight onto another board or module due to the notched edges.

Why are Castellation PCBs used?

Compact size, multifunction, and high density have increased with the growth of electronic products. The PCBs’ size is continuing to decrease, while the boards’ geometric index is rising daily. Consequently, a change to the soldering procedure is also required. Cold solder will come from using soldering flux to connect the circular hole to the motherboard. The daughterboard and motherboard will have a poorer electrical connection as a result, primarily because of how big the hole is. The electronic device won’t function properly as a result. Thus, the need for plated half-holes is growing every day.

A PCB board’s edges are dedicated to the castellated holes. They may duplicate a PCB circuit’s majority of its components. Assume we have an inverter or filter in our circuit. These little sub-circuits are mass-producible. After that, we may connect them to the main PCB board that carries the circuit’s other components. The castellated holes so copy that specific area of the main printed circuit board.

The following are some applications for castellations:

A smaller section of a larger PCB can use castellated PCBs as breakout boards.
Castellated holes connect two PCB boards and confirm the solder joint’s reliability.
Wireless PCB-to-PCB links can also be created using castellated holes.
We can produce integrated modules on a single PCB using this technique. These modules can support additional PCB assembly steps.
We are able to customize the component’s pin arrangement to our preference by using these castellated holes.
This technique is commonly used with breakout boards or small modules such as Wi-Fi modules.

Types Of Castellation:

Full Castellations:

A printed circuit board (PCB) with its entire edge notched to create a series of extensions resembling a castle’s battlements is known as a full castellation. Because the castellations may be soldered straight to matching pads on the mating board, this design facilitates simple soldering and electrical connections between two PCBs. When a PCB module or daughterboard needs to be safely attached to a main PCB, as in wireless communication modules or sensor boards, full castellations are frequently used. Castellation PCBs frequently use PCB modules to offer extra features and functionality. A printed circuit board (PCB) module is a compact circuit board intended for integration into a larger PCB or system.

Staggered Castellations:

Staggered castellations are a variant of full or partial castellation designs in which the notches are spaced apart along the PCB’s edge. Full castellations are one kind of castellation design. This arrangement can increase the mechanical stability of the joint between two boards since the stress is distributed more equally throughout the solder joints due to the staggered pattern. Staggered castellations are frequently utilized in high-vibration settings or in applications (like automotive or aerospace electronics) where the PCB connection may be mechanically stressed.

Partial Castellations:

Similar to full castellations, partial castellations or half castellations have notches on only a piece of the PCB edge. This arrangement is typically used when constraints on space prevent the use of full castellations or when only certain areas of the board need electrical connections. Applications where a PCB needs to be connected to a flexible circuit, like tiny power supply modules, need for partial castellations.

Mechanisms for Castellation

To maximize the electrical and mechanical performance of the connection, a number of standard configurations can be used in addition to different types of castellations. The choice of castellation type and configuration for use is determined by the particular needs of the application, including the desired electrical performance, mechanical stability, and available space. Each castellation type and pattern has unique advantages and compromises. Among these configurations are:

Single-row castellations: Along the PCB’s edge, a single row of notches is made. The most popular and basic design, it can be used for a variety of purposes.
Double-row castellations: On the edge of the PCB, two parallel rows of notches are made to improve mechanical stability and boost connection density. When more mechanical support is needed or in high-density interconnects, double-row castellations are frequently used.
Interleaved castellations: Each notch in a row is offset from the notches in the row next to it, creating an interleaved pattern in the castellations’ notches. Through a reduction in crosstalk and signal interference between adjacent connections, this arrangement can offer better electrical performance.

Basic Guidelines for Castellated PCBs Holes:

Here are some recommendations regarding Castellated Holes’ specifications. There are various design features that you should consider while using castellated holes for PCB soldering. You need to stick to these qualities while making sure everything is done correctly. The following is a list of suggested measurements for castellated holes:

Pad Design: It is preferable to use the largest pad that is available for use. The castellation PCBs fit together correctly when the largest possible is used for each one.
Diameter and Distance: Both standard and advanced PCBs use castellated holes. The minimum castellated hole diameter for typical PCBs is 0.6 mm. The castellated holes on modern PCBs should have a lower diameter as possible. There should be a minimum of 0.55 mm between two castellated holes.
Surface Finish: You must carefully consider the surface finishing in order for the PCBs to mount appropriately. For PCBs, ENIG finish can be the ideal surface finish. However, based on how the boards will be used, you can select the finish type that you like most.

Some basic suggestions are:

Identify the requirement for castellations in your IoT device.
To ensure the correct alignment with the mating board or module, take into account the orientation of the castellated holes.
Based on how you solder and assemble the castellations, determine the right size and shape for them.
The number of holes on the board is always kept to a minimum when utilizing castellated holes for soldering. Looking for the ideal number of castellated holes can greatly improve alignment and assembly ease. But the number of holes should always match the pattern of the boards.
Enough space should be left between castellations during assembly to avoid solder bridging.
Choose PCB material that not only supports the castellation’s durability but also satisfies the mechanical and electrical requirements of your application.
To avoid unwanted solder connections, apply a solder mask to areas that are not supposed to be soldered.
Make sure your PCB manufacturer has clear assembly instructions that include information on solder paste application, alignment, and reflow profile.
Carry out the PCB testing procedures, making sure to test the electrical connections’ continuity.
Consider the temperature, humidity, and other environmental factors when selecting materials and finishing for your IoT device.
Cooperate closely with your PCB manufacturer, keeping lines of communication open and attending to any queries or worries they might have while the product is being manufactured.

You can create castellated PCBs that precisely match the requirements of your IoT device by taking all of these factors into account, ensuring reliable service as well as ease of assembly. To achieve the best performance, the design can be improved with frequent testing and cooperation with experienced PCB manufacturers.

How Castellated Holes are Designed in Altium:

There are a number of ECAD tools in the market to meet the standards of PCB design. Some of them are Allegro, cadence, Eagle, Altium Designer, and Kicad. Altium has a strong and adaptable PCB design tool has support for castellation PCB. Designers may effortlessly generate and enhance castellation patterns, oversee pad designs, and guarantee appropriate inter-castellation spacing with its sophisticated routing and layout capabilities. Additionally, design rule checks (DRC) are integrated into Altium Designer to assist in locating and resolving possible problems prior to manufacturing.

Following are the steps to design single-edge castellated holes as components.

1) Select a pad from a toolbar and place it.

2) Double-click on the pad and select properties. Now add the following parameters of the pad.

 Hole size=.76mm

 X size= 1.5mm

 Y size= 1.5mm

3) Select a line and place a rectangular region with the following parameters.

4) Now select an arc from the toolbar and place it on the edge of the pad. Select the width of the arc as 1mm.

5) Select all lines along with the arc, go to the toolbar select the following, and convert into a region.

6) Make a solid region and paste the same region into the following layers as it is.

Top layer
Bottom layer
Top solder
Bottom solder
Top paste
Bottom paste

7) One castellated pad is created. Now place it at a distance of 2.54mm and make it a component.

You can check it in a 3D view as well.

How Castellated Holes are formed on PCB?

Drilling plated through holes around the board’s edges makes castellated holes. Fabricators must divide the holes along the edge into halves after drilling and then attach the pad to it. The subassembly circuits can be soldered to the main board using these plated semi-holes as soldering pads. These holes are made using a procedure known as side plating or edge plating.

Make sure that there is no gap between the two boards while soldering because it will have adverse effects electrically and mechanically.

Castellation PCBs have many benefits in a range of applications, such as wearable technology, game consoles, consumer electronics, and smart home systems. They are the perfect option for connecting and integrating electronic components because of their small size, simplicity of installation, and enhanced electrical performance. Engineers and manufacturers may optimize their designs for performance, reliability, and manufacturability, eventually improving the end-user experience by understanding the design, manufacturing, and testing procedures involved in generating castellation PCBs.

What is Multilayer PCB?

Multilayer PCB: Design, Manufacturing, and Considerations

A multilayer PCB is a set of more than two copper foils placed together in a single PCB unit in such a way that each foil is coated to provide insulation to the other.

A multilayer PCB has double-sided inner layers and single-sided outer layers at the top and bottom.

A Multilayer PCB Core is coated with copper foil on both sides. Heat is used to cure and solidify it, making it more durable than prepreg. Prepreg, which is made of woven glass cloth and epoxy resin, is used as an isolating material between copper layers and cores.

Through-hole components have connections to all layers with their own through-hole plated pads, whereas surface-mounted components are connected through vias. In multilayer PCBs, there are three different types of vias that are utilized: Buried Vias, Blind Vias, and Through Hole Vias.

All these three types of connectivity services can provided by leading manufacturers like PCB Runner, which are established in the UK and Europe.

Significance of multilayer PCB in modern technology:

The capacity of multilayer PCBs to fit more components into a smaller area is one of their primary benefits. Designers can reduce the total size and weight of the PCB by more effectively distributing the circuitry by utilizing multiple layers. Particularly useful for small electrical devices like wearables, tablets, and smartphones.

In addition, multilayer PCBs provide better signal integrity than single-layer and double-layer models. In order to provide clear and reliable signal transmission, extra layers, as well as dedicated power and ground planes, aid in lowering noise and interference. For sensitive analog applications and high-speed digital circuits, multilayer PCBs are important. Depending on the design specifications and circuit complexity, a multilayer printed circuit board (PCB) may have one or more layers.

In complex analog designs, controlled impedance tracks are under special consideration to avoid cross-talk in the design. We at PCB Runner verified the functionality of providing the required technical data and carried out different tests to make the design successfull and fully functional.

Here are the manufacturing capabilities of PCB Runner which can help you in designing your next multilayer PCB:

Parameters	Specifications
Layers	1-50 layer
Board Material	Rigid: FR4: KB6164, KB6167, S1000-2M, S1000H, TG150: KB6165 Rogers: R4350B, R4003C Metal Core: T111 AL Halogen: S1150G TG135:ShengyiS1141/ KB6160 (CTI175-249）Polymide: Thinflex PI, Panasonic PI
The impedance value and tolerance	minimum 40+/-5% ohm & max 120ohm +/-10%
Inner line width/ Line spacing (original)	For Rigid: 1oz = minimum 3 mil& max no limited 2oz = minimum 6 mil 3oz = minimum 8.5 mil 4oz = minimum 11 mil 5oz = minimum 14 mil 6oz = minimum 18 mil For Flex: 1oz = minimum 2.5mil & max not limited. 2oz = minimum 6 mil 3oz = minimum 8 mil
The group of impedance	min & max, no group QTY limited, we can calculate the impedance per your spec
Vias	Blind, Buried, Plugged, Via-in-Pad, Micro via
BGA PITCH	minimum 0.10mm- max 0.12(mm)
Blind VIA / BURRIED VIA	minimum – max (mm) Stacked 0.10mm Staggered 0.10mm
Laser Drill Size	Minimum (mm) 0.10 Max (mm) 0.12
Aspect Ratio	Laser Drill (minimum 1:1.3& standard 1:1) Mechanical Drill (minimum 1:12& standard 1:8)
Tests	Flying Probe test OR E-Test Functional testing for the specific design Impedance Test Solderability Test Stress test for Pcbs Hole wall copper plating test to ensure required thickness.

Design Considerations for multilayer PCB:

The following are the factors that are under consideration while designing multilayer PCBs.

Choosing the Right Type:

There are four types of multilayer PCB that can be considered before designing:

 Rigid Multilayer PCBs

 Flex Multilayer Circuits

 Rigid-Flex Multilayer PCB

 Metal Core Multilayer Boards

Designing Layer Stackup: Layer stackup is the primary distinction between multilayer and single/double layer Pcb. Performance, density, circuitry, and cost are factors that are associated with the layer stack. After choosing the material based on the functionality of your circuit, it is crucial to organize the layers based on the results of your impedance calculation and the functionality of your circuitry. The next steps are taken after determining layer management and count. Careful calculations must be made in accordance with the design, as the addition and subtraction of a single layer might cause pain throughout the entire procedure after the layer stack is complete.

Component Placement: Placing printed circuit board components is the second critical step after choosing a layer stack. Analog-sensitive components must be placed apart from digital circuits so as not to interfere with the circuit board’s ability to function. Similarly, Rf component location is crucial, and enough ground shielding is required while taking EMI/EMC effects into account. It is crucial to properly function ICs that coupling and decoupling capacitors are placed close to corresponding pins. After completing proper placement, it is easy to handle the routing of tracks.

Power Distribution and thermal management: In Pcb design, the distribution of power is a key aspect of electronic design that needs to be planned and thought out carefully. While a poorly constructed network can result in problems like voltage drop, overheating, and component failure, a well-planned power distribution network can guarantee the dependability and performance of the electronic device. Similarly, thermal management of power-generating components is very necessary. To control the board’s temperature, a variety of heat dissipation strategies can be used, such as the placement of heat sinks, thermal pads, and thermal vias.

Signal Integrity: When choosing trace lengths and layer thicknesses for high-speed signals, take care to provide controlled impedance.
To preserve signal integrity, use appropriate routing approaches, such as avoiding sharp and rough bends and making sure that trace lengths are constant. To prevent electromagnetic interference (EMI) and electromagnetic compatibility (EMC) problems, use ground planes and shielding techniques.
Keep noisy or high-frequency signals away from sensitive traces to minimize cross-talk.

Compliance and Standards: Make that the design complies with industry standards and guidelines relevant to the particular application, such as RoHS (Restriction of Hazardous Substances) compliance, IPC Class 2, and IPC Class 3.

Manufacturability: The designer should consider the capabilities provided by the manufacturer where the PCB will be manufactured. When designing a PCB, the minimum and maximum values have to be taken into mind by electronic manufacturing services. Circuit board manufacturers require accuracy while handling complicated designs. When designing a complicated design, cooperation, and communication with the manufacturer are essential because it helps save money, effort, and time for all involved.

Conclusion:

Before selecting your PCB manufacturer for your multilayer PCBs, you need to check if the manufacturer employs a skilled engineering staff of highly qualified and dedicated professionals in the latest technologies who make sure that you receive an optimized design from the outset, increasing the probability that the design will be completed on time. It will be great if the manufacturer also provides assistance in selecting the best material in order to meet your requirements.

In UK and Europe, there are few manufacturers like PCB Runner who can do everything under one roof. To get white gloves service, feel free to contact us or get a free quote now!

PCB Components Placement Guidelines

Guide to PCB Component Placement for Efficient Assembly

The connectivity in the Printed Circuit board plays an essential role in the PCB assembly process. Accurate placement of electrical components occurs during assembly, which can help connect functional components and interconnect circuitry in the PCB. Careful consideration of parts specification, orientation, and component placement can help your final product be long-lasting and comply with industry standards.

Following are the steps which can help in positioning PCB components during assembly:

Using the PCB layout software to plan the placement of components before assembling the board can help ensure that the components fit correctly on the board and the board acquires a clean and organized layout.
It is recommended to always check with manufacturers like PCB Runner and follow the recommended component placement guidelines.
Using a stencil to apply solder paste to the board before placing the components can help get good solder joints.

Placing the components on the board diligently ensures they are aligned and seated properly. Using tweezers or a vacuum pickup tool to handle SMD components can also help.

Always check the polarity and orientation of the polar components before soldering.
Apply heat to solder the components to the board by hand or using a reflow oven. Follow the recommended temperature and time settings for the solder paste and components.

After soldering, perform visual and X-RAY testing to ensure all components are correctly seated and soldered.

In conclusion, component placement guidelines can make the printed circuit board efficient and low-cost. All the designers should check with manufacturers like PCB Runner for component placement guidelines before designing the circuit board for accurate placement of electronic components.

PCB Stencil – A Beginner’s Guide

Guide to Printed Circuit Board (PCB) Stencils

A printed circuit board (PCB) stencil is a thin metal sheet with laser cutouts used to apply solder paste to a PCB. The solder paste is a mixture of metal solder and flux that connect surface mount components to the PCB. The following is a guide to PCB stencils:

Stencil Thickness:

The size of the components used in the printed circuit board and the complexity of the design affect the stencil thickness. Thicker stencils are more robust and will last longer, but thinner stencils are more flexible and easier to use.

Stencil Design:

CAD software creates the stencil design, which generates a file in Gerber format. The Gerber file includes the paste layer needed to make stencil cutouts. Some stencil manufacturers like PCB Runner offer design services, so you can send them your PCB design files, and they will create a stencil design for you.

Stencil Production:

Stencils can be manufactured in many different ways. The most prevalent techniques are chemical and laser etching. Laser and chemical etching are the most common ways. Laser cutting is faster and more accurate but expensive. Whereas chemical etching is slower, it is more cost-effective for small production runs.

Stencil Inspection:

Stencils must get checked for any defects or damage that could affect the solder paste application.

Stencil Storage:

PCB stencils are stored in a dry, cool place to prevent corrosion. Handling the stencil is essential to avoid bending or scratching the surface.

Stencil Application:

Place the stencil over the PCB and align the cutouts with the SMD pads.
Use a squeegee to spread the solder paste over the stencil and through the cutouts.
Remove the stencil carefully; the PCB is ready for component placement and soldering.

PCB stencils are essential tools for producing high-quality PCB assemblies. With the right design, production, and usage, stencils can help ensure that the PCBs are reliable and functional.

Soldering techniques for PCBs

Soldering Techniques for Printed Circuit Boards (PCBs)

Soldering techniques for printed circuit boards (PCBs) are essential for anyone who wants to work with electronic circuits. The soldering process includes joining two metal surfaces with a filler metal called solder. This article will discuss some of PCBs’ most common soldering techniques.

Through-hole soldering:

Through-hole soldering is one of PCBs’ oldest and most common soldering techniques. It involves inserting components into pre-drilled holes on the PCB and then soldering the leads of the components to the pads on the opposite side of the board. This technique benefits large parts, such as connectors or transformers, which require mechanical support.

To perform through-hole soldering, you will need a soldering iron, a soldering stand, a flux pen, solder wire, and a pair of pliers. Start by cleaning the tip of your soldering iron and then applying a small amount of solder to the tip to help transfer heat. Next, apply flux to the pads on the PCB and insert the component into the hole. Hold the component in place with a pair of pliers and then apply heat to the pad and lead using the soldering iron. Once the solder has melted, remove the iron and allow the joint to cool.

Surface-mount soldering:

Surface-mount soldering is a newer technique for small electronic components that do not have leads that go through the PCB. Instead, they have pads on the surface of the PCB to which they are soldered. This technique is beneficial for small electronic devices such as smartphones and laptops.

To perform surface-mount soldering, you will need a hot air reflow station, a flux pen, solder paste, and tweezers. Initially, the flux is applied to the SMD pads, then a small amount of solder paste is printed on the respective SMD pads. Due to tiny components, the components cannot be hand placed. In this case, tweezers will help place the components on the paste with proper alignment. If this process is done manually, tweezers can help place the components on SMD pads. After placing the components, the boards go into the hot air reflow over or station in which they are pre-heated for a specific period, and as time increases, the heat melts the solder paste and glues up the components on the PCBs. After the process the board heating process, the machine decreases the temperature to a certain amount with time to cool down the assembled boards. Most EMS providers perform these tasks through automated pick-and-place machines, which help achieve accuracy and save time.

Wave soldering:

The wave soldering process helps assemble high-volume quantities with through-hole components. It helps all the through-hole components to get soldered in less time and with accuracy, as suggested by IPC. The process starts by passing the PCBs over the molten solder wave, which touches with the Plated through hole components leads and creates a strong joint between the board and the components.

Wave soldering machines are industrial machines primarily available at Electronic Manufacturing Service providers like PCB Runner. The required types of equipment are similar to SMD, like a flux applicator, solder wire, and a pre-heating station. The process starts with applying flux on the PCB and placing the Through hole components by hand. After placing all the components, the boards are passed through the pre-heating station to warm up the PCB and settle the flux on the PCB. After the PCBs are placed on the rail, the rail takes the PCB forward to the molten solder, which wets the pads and creates strong solder joints between the components and the boards. After a successful trip of molten solder, the PCBs get into a cooling station to cool down the molten solder.

In conclusion, soldering techniques for PCBs are essential skills for anyone working with electronic circuits. Through-hole soldering, surface-mount soldering, and wave soldering are the most common techniques used for PCBs, each with advantages and disadvantages. Understanding the different techniques and their applications allows you to choose the most appropriate technique for your project and produce high-quality solder joints.

Archives