Important Considerations for PCB Assembly

mwcms on December 10, 2021

Designing and assembling PCBs is an incredibly valuable skill. Nowadays, it is a process that is easy to learn and implement, as long as you are willing to invest your time in it. Back in the early days, the PCB assembly process was time-consuming. However, today, you have many software programs that allow you to design them and get them delivered to your doorstep.

Nonetheless, any mistake that you make in your design can be very costly to you. This is because your design will dictate the assembly process, along with the functioning of the board. With a nonworkable board, the electronic device will also suffer from malfunctions and errors.

To avoid these errors, you must take certain things into consideration when assembling and designing a PCB board.

Do not be Impatient

A printed circuit board is a piece of technology that has a precise and sophisticated design. Each detail is thought-through and requires careful considerations. This is why you must never be impatient in any of the PCB assembly processes.

Most people make the mistake of being impatient when they are placing components on the board. According to professional PCB designers, it is integral to have most of the time go to components placement when designing and assembling the PCB.

This is true because the placement framework will ultimately determine the outcome of the PCB design. The trick is to avoid overlapping the rubber panels. Moreover, you have to keep adjusting each placement until there is no overlapping.

When designing, if you spend enough time on your digital component placement, your routing will be significantly easier.

Consider Routing Directions

Once you complete the component placement, then you will have to move forward to routing. For this, you will have to decide the routing direction of a particular layer before laying down the traces.

Make sure that you set the right directions as even the slightest inconsistencies in direction can lead to complete design failure.

Narrow High Current Traces

Make sure that you do not develop the habit of using the same width for all the traces in your design; well, you do not want to do that. Make sure that your traces can withstand the maximum voltage.

If a particular trace carries a higher trace width than the other traces in your design, make sure to increase the width for the others as well.  High-width traces ensure proper heat dissipation.

Make use of Copper Pour

Making PCBs involves etching the unused copper and leaving the traces intact. Copper pouring means that you have to use unused copper for any signal instead of etching it out. You have to do it by creating spaces for traces and pads.

Commonly, people will use them for power signals or ground signals. This offers a low impendence path for the current and also makes connection much easier.

Pay Attention to Spacing

Most designers do not consider the importance of spacing and end up making a flawed printed circuit board. Proper spacing requires much more effort and consideration.

Thus, designers should be well aware of the adequate spacing requirements for a particular circuit.  You should also consider the assembly of components to ensure proper spacing.

Final Thoughts

These are just a few of the many considerations that you should take when performing a printed circuit board assembly. As you can see, the design process is very important as it can account for an efficient and safe assembly.

The Various Ways of Circuit Board Assembly

mwcms on November 29, 2021

When defining printed circuit boards, one can resort to a number of different explanations. Nonetheless, to put it simply, it is an integral component inside all electronic devices. And it is responsible for the smooth flow of electricity across all parts.

It also consists of very small metallic insertions that create a pathway for the smooth movement of electricity across all components inside an electronic device.

It is safe to say that PCBs have made it possible for all modern electronics to exist. By carving the way for the smooth flow of electricity, it makes all electronic functions within a device operable.  After you create a printed circuit board, you can move on to the next step, which involves the assembly process.

Circuit Board Assembly

The printed circuit board assembly process requires you to connect the components inside electronics with the wirings that you find on these circuit boards. PCBs have a non-conductive substrate, along with a laminated copper sheet in which conductive pathways are present.

These pathways are indentations on which electronic components can attach and receive sufficient electricity. There are different ways of assembly through which one can mount the components to the board.

Different Ways of Circuit Board Assembly

Assembling the printed circuit boards is a process that requires significant care and inspection. Each process needs to be precise and thorough as even the slightest mistakes can lead to a non-functioning device, and you don’t want that.

As assembling the electronic items to the circuit boards is the main and deciding factor, it is important to determine the different methods to pick. There are three assembly ways for attaching electronic machines.

Surface Mount Assembly (SMT)

The surface mount assembly technique is an old school yet effective assembly technique. In fact, it is so effective that even to this day, people use this method. It emerged in the 1960s, and the process was finalized and developed in the 80s.

Manufacturers continue to resort to this assembly process as it requires fewer resources and also offers precise results. In this process, manufacturers use metal tabs and solder material to mount components to the printed circuit board.

Overall, this method uses effective soldering techniques and higher circuit volumes, considering that the components attach to both ends of the circuit board.

Electro Mechanical Assembly

This type of circuit board assembly often deals with larger components. Another name for this assembly is box-built assembly. In this method, one has to use techniques that revolve around elements such as harnesses, looms, cables, metalwork or molded plastics. These elements play an integral role in the circuit board assembly.

Plated through-hole Technology (PTH)

This process is one in which you have to sort all components with lead attachments. For this type of assembly, manufacturers require PCBs with holes drilled into them. These holes contribute vastly when assembling the PCBs, as manufacturers can mount the components onto the board by passing the lead through the holes.

The Future of PCB Assembly

The future looks very promising for PCBs. As new innovations emerge in the field of microelectronics and machine learning becomes more widely adopted, it is inevitable that the assembly process will only get better and more optimized.

Final Words

Ultimately, the improvement in the circuit assembly process means the improvement of electronic devices. This is largely because an accurate assembly process ensures that all processes inside an electronic device operate smoothly.

Practices that Account for Flawless PCB Assembly

mwcms on November 9, 2021

Printed circuit boards are the basic parts of all electronic components, as they are responsible for the smooth flow of electricity inside the device. Without this distribution of electricity, all electronic components will fail to function.

Nonetheless, for a printed circuit board to perform its job efficiently, it is important that it works efficiently without any flaws. For the printed circuit board to work well, its assembly process must adhere to some important set of practices and standards which help make the PCB functional and smooth.

Inspect the Materials

Your PCB is as good as the quality of materials and components that you use. Professional PCB assembly units place a high priority on the material they use when putting together a PCB, as this can be critical.  You want to make sure that you place a high value on quality control when assembling the components on the board.

Maintaining quality requires inspection, testing, and verification of several components and processes involved in the PCB assembly. For instance, you have to take into account factors such as the quality, model number, and data code and make sure that it matches with the BOM.

Inspecting the material and components will involve running multiple tests. These tests can include sample testing, material operational testing, and others.

Furthermore, you can also check whether the components are oxidized, deformed or damaged before applying them to the assembly.

DFM Check

This is another way you can make sure that your PCB works smoothly and efficiently. Running a design that focuses on DFM checks allows manufacturers or people working on PCB projects to create a seamless assembly and identify errors that can be potentially problematic at later stages of assembly.

Furthermore, this test can unveil many flaws pertaining to component polarity, spacing, footprint corroboration, and more.

By doing so, a DFM test can significantly decrease the cost of manufacturing and speed up the delivery process as well.

Not to mention, by revealing the flaws to you in time, the DFM test also saves the time you need for the rework process. Ultimately, all of these benefits translate into improving the quality of the product significantly.

Inspect Solder Paste

Solder paste application is crucial to the PCB assembly process. The solder paste is the material that holds the components on the board with strength. Application is done with the help of a machine, as it holds the stencil over the board, after which the solder is poured on the surface of the board.

These open spaces are where the surface mount components are placed. Thus, people working on circuit board assemblies should ensure that the solder mask they use has good composition so that it is applicable for assembly.

An inspection of the printed circuit board should always follow the solder mask test and application. This determines whether the board will hold all the components.

Sound Communication

When designing and creating a PCB for another person, it is important to understand what the other person is exactly looking for. Setting a clear line of communication will lead to a PCP that fulfills all the necessary needs and preferences.

Finally

With the use of advanced technologies, you can create a PCB that ticks all the boxes relating to reliability and accuracy. These technologies take shape in the form of tests and inspection tools. When you run your PCB through some of the tests above, it guarantees a final product that is flawless and seamless.

What Goes into Assembling a Circuit Board?

mwcms on September 24, 2021

Do you ever wonder how and who developed the technology we use today? Well, we will not get into technical and complex details of how some things were possible, and others weren’t. This article will primarily focus on the assembly of printed circuit boards (PCB). All modern electronic and digital equipment have PCBs as an essential component.

These circuit boards are the foundation of major electrical equipment because they provide the connection for different parts and components of a digital electronic device.

Assembling a Circuit Board: Step-by-Step

If you want to assemble a circuit board on your own, you will need clear instructions and, more importantly, the right assembly guide. There are many key components that you need to consider when working on a major type of circuit board. However, when assembling a PCB, you have to be extremely careful to avoid errors, functional problems, and/or delays.

The main components of a typical PCB include a plastic or resin board that comprises different conductive and non-conductive metal parts. The silkscreen on the PCB guides the assembler on how and what connects on the board. Furthermore, you should know that the more components that a PCB requires, the longer it will take to assemble it. Let’s take a look at the four main steps of assembling your PCB below.

Step 1: Schematic Designing of the Board

You should create a schematic design before the production of the actual PCB. It serves as a silkscreen that looks like a roadmap. It means that the lines on the schematic design help to point out which component connects with what on the PCB. In general, a schematic design represents the whole circuit board. Hence, if any issues arise, they will be easy to resolve due to the schematic drawing.

Step 2: Board Design Layout

Now, the more important step. You have to convert, or more precisely, “translate” the schematic drawing into an electronic design. Bear in mind that the electronic design is present in automation software. After exporting this design in any acceptable format, you can begin the production of the board.

Step 3: Production and Assembly of the PCB

The production of the PCB is critical. You have to define all the dimensions and angles accurately to create the board finally. There are various circuit board manufacturing technologies that you can use as an assembler. The most common ones include thru-hole and surface mount technology. However, which technology you use will depend on the board’s specific requirements.

Step 4: Final Testing of the PCB

The process doesn’t end with the production of the circuit board. The last part of the assembly involves testing the board to ensure all PCB functions are achievable. The final testing phase checks and ensures that the design of the PCB is error-free and matches the schematic drawing.

Conclusion

As technology keeps evolving in various industries and fields, we have better and more efficient means of getting work done. However, technology encompasses a wide range of digital, electrical, and physical components in place. When assembling a PCB, you have to make sure that you take your time while producing schematic designs, choosing technology for production, and actually manufacturing the board. Slight errors can make the entire PCB non-functional. So, follow the step-by-step guide to ensure you don’t make any mistakes.

Reference Links:

https://www.permatechelectronics.com/the-steps-that-a-circuit-board-assembler-takes-in-pcba/blog.html

https://www.tempoautomation.com/blog/what-your-cm-wants-you-to-know-about-how-to-assemble-a-circuit-board/

https://en.wikipedia.org/wiki/Printed_circuit_board

https://www.electronicsmedia.info/2019/05/27/how-to-assemble-a-printed-circuit-board-pcb-assembly/

Everything You Need to Know About Circuit Board Assembly!

mwcms on September 13, 2021

Most of the electrical appliances that run our lives on a daily basis include about 300 feet of tiny wires inside. This wire is the main component that adds connectivity inside an electrical product. It allows all the other small components in an electrical appliance to work seamlessly together.

The more complex an electrical appliance is, the larger the number of components and the wire inside it. However, you may be wondering where this wire is located. Well, this is where the printed circuit board assembly comes into play.

What is a PCB?

The printed circuit board or PCB is the small circuit board inside most electrical appliances. They are either green or blue and at first glance, they look like ordinary pieces of scrap plastic. But in reality, they are actually a multi-layered board that consists of an abundance of copper wires.

This scrap of flat metal is the surface on which manufacturers will precisely and carefully place all the essential components using expensive heavy machinery. Along with that, small copper wires will connect between the components and provide the necessary connectivity that occurs between all the components. This connectivity allows the components to work together and as a result, this paves the way for an electrical appliance to function.

What is inside?

The printed circuit board consists of ten conductive layers. The top and bottom layers of the Circuit board assembly make for surfaces on which manufacturers will mount components and they also act as multiple antennae. Moreover, each of these components on the circuit board requires plenty of power and ground and the PCB has entire layers that are only responsible for providing power and ground.

They are also aptly named power planes and ground planes due to their specialized role. Other ground planes that make the circuit board assembly serve the purpose of electromagnetic shielding and heat dissipation. The remaining four middle layers carry all the communication traces, which means that they carry all the signal wires.

Each of the conductive layers is copper, and between these conductive layers, there is insulating fiberglass, along with an epoxy resin that protects against the flow of electricity between the layers. A common PCB has a total of ten conductive layers, however, in a more technical and complex application, the layers can range up to 50 or more layers.

On the other hand, you may also find a PCB board that is simpler, with only two layers. Not to mention, on the top and bottom layers of a PCB, you will find a coat of solder mask, which offers a surface on which manufacturers will place components using high-tech machines. On top of the soldering mask is the silkscreen, which is nothing but the ink that indicates the placements for components by marking the circuit board.

The Assembly Process

After all the components of the PCB are manufactured, they need to be assembled before the PCB can go into the production line. This assembly process will involve the application of solder masks, automated component placement, along with the electrical testing of the bare board.

Final Thoughts

Printed circuit boards are more widely used inside computing devices, and since each model of smart phones and laptops along with other devices are different, the shapes and designs of circuit board assembly also differ vastly. Overall, it is fair to say that they are integral components of the modern technical era, and without them, none of the highest technical appliances can function.

 

 

The Process of a Printed Circuit Board Assembly

mwcms on August 30, 2021

The PCB assembly process undergoes thorough and intricate steps. PCB’s being the staple circuit board mechanism in most of the electronic appliances is undoubtedly major components that require perfect assembly otherwise they can be major causes of concern for many industries.

BluePrints and Layouts

The assembly process in factories start with a framework or blue print layout and make their way to the customers. Due to the advancements in PCB production, modern manufacturing units hardly have any workers on the production floor. This is because most of the manufacturing process is subject to automation and efficient machinery.

In the starting stage of assembly, the burr board inserts into the laser marking machine, which marks a serial number on the board so that the board can have a manufacturing label. This process is common in large scale production, but is not something common to all Printed circuit board manufacturers.

Applying Solder Mask

The process initiates with the application of solder to the circuit board. Solder mask is a material that sits on top the circuit as a layer in which you can install components of the circuit board. A specific inspection machine then inspects the circuit board and ensures that it is aligned.

Once the inspection is complete, it applies solder all the way across the surface board in an evenly fashion. After solder application, the solder goes through another inspection to ensure that it is applied evenly.  Once the inspection is complete, the board is ready to undergo the next stage.

Adding Component Placements

The next stage involves the addition of the placements. Machines rapidly add placements on the board that are coming from the reels. This machine includes heads that pick up the reels and attaches them to the circuit board. This reel placement happens for about eight times before the circuit board is ready for the next stage.

After all the components attach to the board, it is then ready for the reflow process. This process is important since the solder needs to melt so that it can adhere and be a good surface that provides mechanical and electrical connections between components and parts.

Reflow process

When it goes under the cooking process of the machine, it comes out from the other side to cool. Cooling process takes place so that all the junctions between the components can form and solidify. This results in the next step which involves testing.

Inspection and Electrical Testing

The final inspection will now ensure that all the components are situated in their correct specific placements so that the circuit board assembly is ready for use.  In this testing, advanced machines identify whether the pins are contacting the pads in the exact location. At this point, the SMT process is in completion.

Electrical testing can have implications that follow two processes. The first involves the bed of nails, which helps manufacturers test at a high volume at a shorter time, however it require expensive fixtures. The second testing method is a flying probe, which is a high mix at a small volume.

If the circuit board assembly includes large BGA components, then manufacturers need to inspect whether the pins are reaching the right layer.  These pins are usually behind each component and therefore, you cannot test those using automated machines. In this scenario, manufacturers will likely use the help of X-ray images and make sure that the soldering and components are adequate.

Parts of a PCB, or Printed Circuit Board

Whether the PCB board is inside an air conditioner, or a refrigerator, you can find numerous different parts mounted on the bare board. The main components that you are likely to find and which are critical for its functioning involve a Fuse, transformer, and a switch. The quantity and types of these components can vary according to the specific electrical appliance.

To Conclude

All of these processes and testing are then finalized by a functional test. As you can see, the process of a printed circuit board assembly is full of inspections and automated machine work. Thus, it is a true reflection of the detailed workings in a mass production factory.

 

Tips and Tricks: Learn to Improve Your Current PCB Design

mwcms on August 4, 2021

Circuit designing can be incredibly daunting when it comes to practical application. Often, PCB designers will make common design mistakes that they can improve, with simple tips and tricks. In this article, you learn how to improve things such as signal integrity, EMI, and so forth.  You will also gain insights over trace widths, via sizes, placements, and clearances between traces.

Use Design Tool Kits

Often time’s people fail to realize the use-cases and benefits of tool kits, and do not utilize them for their PCB design. This is somewhat of a mistake, considering that you can find free toolkits online that can help you make a series of calculations that can help perfect a PCB circuit. It is most useful for conductor impedances, crosstalks, differential pairs, and so on.

Coupling and Decoupling Capacitors

Capacitors can come in as very handy components when building a PCB circuit. They act as timing elements or filters. When you use them as decoupling capacitor, you need to connect them in parallel with the power supply.

Why should you do this? Well, you should not expect power supply of any kind to be flawless. The output from these will have a fluctuating property. Hence, this is where a decoupling capacitor can help. Adding it into the circuit will prevent the fluctuations from the supply to reach the digital pins.

Pull Up and Pull Down Resistors

In digital circuits, the conventional way of feeding input involves using switches or push buttons. When you do that, you run into the risk of leaving the input pins into your floating state. This is where the input prints of a chip cannot detect input logic and ultimately lead to an unexpected outcome.

If you want to avoid this common floating state issue, you can use resistors of specific value to improve your PCB circuit. Resistors such as Pull up or Pull down resistors connect the input pin to VCC, so that it can read, “LOGIC 1”. Whereas, a Pull down resistor can connect the input to the ground, and you can use it to read, “Logic Zero”

Discharge Time of Batteries

Your design needs to be compatible with batteries. The most important tip, when powering your circuit with batteries, is to calculate the discharge time of the battery. This tip is helpful because if you attempt to discharge the battery capacity, more than its optimum level, you run the risk of permanently damaging your battery.

As a rule of thumb, you choice in batteries should have about 1.5 times more capacity than your circuit’s actual consumption. However, make sure to check the datasheet because of the invariabilities within the battery chemistry.

If you are designing a circuit that requires one ampere for an hour, then a battery that holds capacity of 1.5 AH is the best choice for optimum performance.

Wattage Ratings

Most people tend to forget about the wattage ratings and focus more on the resistor value of the circuit. Wattage rating of a resistor refers to the maximum amount of power that a resistor can safely dissipate in the form of heat.  If the dissipation in the resistor exceeds the maximum wattage rating, then the resistor is likely to crash.

This is why finding a wattage resistor that corresponds to your circuits resistance value is a tip that will not only improve your circuit design, but also save it from smoking. Hence, you should pay close attention to the power dissipation of a particular resistor.

To Conclude

Most of the times, it is the small changes in PCB design that make the biggest improvements. Therefore, make sure to keep track of all the small measurements and calculations if you want to optimize your circuit for it to work in its highest capacity.

PCB Finishes: Immersion Silver

mwcms on December 7, 2020

It is a well-known fact that printed circuit boards (PCBs) use copper surface finishes as a common practice. If left unattended and unprotected, copper will deteriorate and oxidize, leaving your circuit board unusable. 

A surface finish plays a vital role in creating an interface between a PCB and its components. Here are two of the main functions of a surface finish.

  • It helps protect the copper-based circuitry
  • It provides you surface that can facilitate soldering during the assembling process of soldering components to your PCB

What Is Immersion Silver?

Immersion silver surface finish is a type that you can apply directly over your printed circuit boards’ copper surface. This surface finish is most commonly used and ideal for metallic dome contacts, aluminum wire bonding, and EMI shielding. 

The thickness of this material is between 5 micro-inches and 12 micro-inches, respectively. Additionally, immersion silver has lasting capabilities for at least a year. 

Immersion silver surface finish does not react to copper the way Tin does. However, if you expose it to the air, it will tarnish; therefore, you must store the circuit boards with immersion silver finish in an anti-tarnishing packaging. 

If you do everything right and store it in proper packaging, the PCB will still be solderable for 6 to 12 months. However, once you have removed your printed circuit board from the packaging, you must make sure that it goes through soldering re-flow within the next 24 hours.

In case you wish to achieve a higher shelf life than gold, plating is the most viable solution. 

Benefits of Immersion Silver Surface Finish

PCBs always come with coated surface finishes. Adding a decent finish enables and ensures decent soldering capability, as well as it protects the copper circuitry of your circuit board from the outside air. There are several types of immersion finishes, such immersion tin, immersion gold, etc.; however, immersion silver is gaining popularity due to certain features it offers. 

It is attracting a lot of attention from the PCB manufacturers. Here are some of the key advantages that declare it to be the preferred material for surface finishing in the circuit board industry. 

  • It allows the proper spreading of solder on its surface, allowing better soldering of circuit board components. 
  • Immersion is one of the RoHS compliant PCB surface finishes, and it is also environmentally friendly. 
  • Compared to OSP “Organic Solderability Preservative” surface finish, the surface with immersion silver finish will demonstrate better resistance to several environmental aging factors. 
  • The immersion silver is a material surface finish that comes with the capabilities to survive multiple re-flows. 
  • Immersion silver has better and enhanced electrical properties. 
  • It produces a flat surface and facilitates strengthened solder joints than HASL surface finish. 
  • Immersion silver is immune to a phenomenon known as a black-pad interfacial fracture. 

All of the advantages mentioned above make immersion silver surface finish an ideal choice for PCB manufacturers. 

Choose Wisely

You must select an adequate surface finish for your PCBs. You can do so by considering several options while you factor material costs and performance requirements. 

For instance, you are looking for an option that is lower in cost than Tin-Lead. HASL may sound like a more obvious choice, but it is not the most suitable option, especially when it comes to RoHS compliant products. 

In case you are unsure of what type of surface finish you may need. You can always get help from third-party PCB fabrication services prior to making decisions you may regret later. A little bit of research will result in cost-effective and high-yielding design.  We are here to answer any questions you may have and help you make the best decision for you. Contact us today!

Cost Reduction Ideas for Your Next PCB Assembly Project

mwcms on November 23, 2020

Are you looking for ways to reduce the overall cost of your next PCB assembly project? If your answer is a ‘yes,’ you are in the right place. 

A fundamental way to contribute to your organization financially is by adopting cost-effective methods to reduce the total cost of printed circuit board assembly projects. You can take many steps to reduce the cost of a PCB assembly project. 

3 Smart Cost Reduction Tips for PCB Assembly Project

Although you can surely make some internal changes in the assembly process and find the vendors offering competitive rates, here are the three most essential tips above all.

Tip # 1 – Providing Multiple Sources for Each Component of the Circuit Board

You must always avoid a single source to procure your components as much as possible. Why? There are several advantages to having multiple procurement sources. 

For instance, you can ensure greater availability of components required for distribution with multiple component procurement sources. Moreover, you can also have the leverage to bargain for components’ costs due to competition in the market. 

The biggest problem associated with single sourcing is, you can end up with a shortage of parts. This may hinder your manufacturing process. Thus, you can always select an alternate source immediately. This will save you both time and additional operational costs. 

Tip # 2 – Optimizing and Establishing Flexible Panelization Process

Always keep your panelization process flexible to the manufacturers’ needs. You must ensure that your PCB panelization process is optimizable as per the requirements of your PCBA manufacturer.

For example, you have a 6-up panel, meaning it can make 6 PCBAs simultaneously. There will be four mounting holes in the corners with .127 diameters; you can comfortably process 6.5 X 4.25 panels with .127 pins for mounting. 

However, if your company uses .250 pins, you must have panels that are 12-up instead of 6-up. It is cheaper to have flexibility in your factory equipment to adopt than to maintain your original design. 

Tip # 3 – Qualifying Lower Costs Sources Rapidly

You must set up a PCB assembly process to qualify cheaper procurement sources between circuit board design engineering and component purchasing departments. However, this sounds easier than it actually is as the conflict between design engineers and the procurement team’s priorities can impede the entire process. 

One of the most effective solutions to this problem is to establish a materials cost reduction committee. The management partners up with both engineering and purchasing departments to identify highly effective cost reduction opportunities. 

Moreover, they also work together to identify strategic and most essential components. This will help them locate multiple sources for these components to ensure a continuous supply for production. 

Final Thoughts

Now that you know three smart tips to reduce your next PCB assembly project’s cost, use them to your advantage. Not only will you be saving money, but these tips will help you optimize your manufacturing timeline. We are here to help with your PCB assembly needs. Reach out to us today!

All the Key PCB Assembly Terms Defined

mwcms on November 10, 2020

Having a fundamental understanding of important PCB (printed circuit board) terminologies can make collaborating with a Printed Circuit Board manufacturing organization much easier and quicker.

Although this list of PCB assembly terms is not all-inclusive or comprehensive by any means, it is still a great resource for your reference. Read on! 

Annular Ring

Generally, there are two Printed Circuit Board drill hole types you can bore during fabrication. One is the NPTH (non-plated through holes) that you use for installation and mounting purposes. The other one is PTH (plated through holes) for VIAs that are current-carrying. 

The annular ring is basically a copper region around the drill hole. It ensures there is a solid connection for VIAs and offers spacing for the application of solder mask.

Manufacturer Part Number

MPN (manufacturer part number) is an identifier for every component on your PCB board and is unique for every component type. The manufacturer part number is different from the reference identifier. The latter identifies every particular component in the BOM of the board and its precise location on the said board. Not to mention, there can be many components with varying reference identifiers having the same Manufacturer Part Number. MPN’s traceability is one of the chief ways of ensuring the integrity of the supply chain. For the development of PCBA, component selection is probably the most crucial task, as a fully successful operation is contingent on the reliability and quality of components. 

Board Thickness

The board thickness is one of the most important terms when it comes to PCB assembly. It is basically the board’s total height (not including the present components). It is common knowledge that the circuit board size (in the horizontal plane) has been reducing to accommodate smaller electronic products and devices demand. The capability to route more signals that enable more functionality and complexity is the chief determining factor for the total number of layers in the multilayer PCB stackups and hence the usage of the greater thickness of the board. 

Copper Weight

Copper weight indicates copper foil thickness on every layer of a Printed Circuit Board. It is generally expressed in copper ounces/ square foot.

Controlled Impedance

Nowadays, more applications are employing IoT (Internet of Things) devices that generally need higher speed transmission of signals. Hence, controlling impedance on the transmission lines of your PCB board has become a very critical consideration for the integrity of the signals. You can accomplish PCB impedance control by matching material impedances and trace to minimize interference and optimize signal fidelity. 

Assembly Drawing

This particular drawing is a reference that depicts the Printed Circuit Board’s assembly. These assembly drawings will often include component placement with the construction methods, technologies and parameters required to make it happen.