Printed Circuit Board Assembly Process – The comprehensive Guide!

By | Date posted: | Last updated: January 19, 2021
Printed Circuit Board Assembly Process

With the usage of PCBs becoming ubiquitous with increased usage of electronic products, it is important to understand the PCB Assembly process in detail.

Essentially, a Printed Circuit Board with components mounted on it is known as an assembled PCB and this process of mounting components on the board is referred to as the process of PCB Assembly.

The PCB Assembly process, in turn, has a number of steps- some of these are automated and some are manual. Here are the basic steps involved in Printed Circuit Board Assembly:

PCB Design

The basic unit of the PCB has a number of layers. These layers include:

  • The base material of the PCB that gives the PCB its rigidity is known as the substrate
  • On each side of the Printed Circuit Board is a copper layer.
  • Above the copper layer is the solder mask. Essentially, what it does is to insulate the copper traces. The solder mask is therefore responsible for smooth working of the PCBA as it ensures that the soldering does not happen on unwanted parts.
  • The final layer on the PCB board is the silkscreen which adds labels and therefore indicates the function of the various components.

Following are the basic types of Printed Circuit Boards:

  • Rigid PCBs: As the name indicates, these are inflexible PCBs. For such PCBs the base is made of materials such as FR4, epoxy or phenolics.
  • Metal core PCBs: As the name suggests they are made of a metal core that spreads heat efficiently and therefore components that are heat sensitive, are protected.
  • Flexible PCB: Flexible PCBs offer more pliability than their rigid counterparts and therefore are of use in several applications.
  • Rigid-Flex PCBs: This is a hybrid design that essentially has the qualities of both rigid and flexible PCBs. Typically these are multi layered with flexible circuit substrates joined with rigid boards.

When it comes to the component mounting technology for printed circuit board assembly, two types of technologies:

  • Surface Mount Technology: This is particularly useful for small, sensitive components such as resistors or diodes.
  • Thru-hole technology: This is useful when components are to be mounted on the board through a process of plugging them through holes on the board. When there are large components, this technology is preferable.

Prior to the PCB Assembly (PCBA) process, however, there need to be some preparatory steps. This largely includes assuring that the design of the PCB is right for which a Design for Manufacturability test is undertaken. This is to ensure that no operational issues are faced once the PCB is ready. A DFM check looks at the various design specifications, any missing features and more, which can impact the functionality of the PCB. For example, is the spacing between components too less, if so, if it not caught at the DFM stage, it could lead to short circuits at a later date. Design for Manufacturing can therefore go a long way in ensuring that costly errors are later avoided.

Printed Circuit Board Assembly Process Flow:

Post the Design for Manufacturing (DFM) test comes the actual Circuit Board Assembly process.

Solder Paste Stenciling

The first stage begins with the Solder Paste Stenciling. Essentially this means applying a solder paste on the board. A thin stencil is placed over the PCB, this allows the solder paste to be applied on certain parts of the PCB. Essentially, the solder paste is a mix of solder with the flux, which needs to be applied to the board at the correct places. Once the stencil is removed, the solder paste remains in the exact location in which it was intended.

Pick and Place

The next step is what is known as Pick and Place. A robotic device now places the surface mount components on the PCB. These are then soldered to the board. While earlier this process was manual, it is now automated that adds to precision and accuracy.

Reflow Soldering

This process ensures that the solder paste solidifies and that components are affixed to the board. Essentially, after pick and place the PCB board is moved to a conveyor belt. It is here that the board is heated to about 250 degrees Celsius, which melts the solder. Now it moves to cooler heaters where the solder cools and solidifies. This now connects the components to the PCB.

Quality Control

After this process, comes the very important process of inspection. It is important to check to see that the connection isn’t poor and that there are no shorts as a result of misplaced components. There are a number of inspection methods that are in use. These include:

  • Manual Inspection- This works well for small batches. However, when the number of boards increase, visual inspection becomes impractical
  • AOI or Automatic Optical Inspection- This is suited for large batches where an AOI machine is used that has cameras at different angles. With different quality solders reflecting light in different ways, it is easy to identify the low quality solder.
  • X-Ray inspection- For layered PCBs, this method works well

Through Hole Components

The board also may contain a number of through-hole components, in which case these components require a special kind of soldering method.

This could be manual soldering where components will be inserted one at a time. The process can be lengthy depending on how many components there are.

There is also wave soldering which is an automated version. However, this isn’t possible for double-sided PCBs

Functional Test

Post this comes the final inspection to test for functionality. With simulated signals running through the PCB at this stage, its electrical characteristics are tested.

This completes the Printed Circuit Board Assembly (PCBA) process. However, soldering can make the process messy. What is therefore extremely important, is to wash the product after the soldering process. For this, a high pressure washing apparatus is used, where the PCB is washed in deionized water. Washing is then followed by a drying process followed by packaging and shipment.

It is also important to note that there are some differences between THT Assembly, SMT Assembly and Mixed Technology.

Through Hole Technology Assembly Process

In this assembly process the first step is that of component placement where components are placed manually conforming to a number of regulations regarding polarity and orientation of components. This is, then followed by a process of inspection. The last step is to do with wave soldering which involves the THT components to be accurately soldered onto the circuit board.

SMT PCB Assembly Process

This process involves the steps of Solder Paste Printing where the solder paste is applied through a solder paste printer. This is then followed by mounting of components through an auto pick-and-place machine that sticks parts to the board. The final step is to do with reflow soldering which binds the components firmly to the board.

Mixed Technology

With electronic products becoming increasingly complex and miniaturization becoming the order of the day, most boards have both thru-hole and SMD components. In such cases it is important to have a proper sequence in order. Hand soldering works well where there are many components on both sides and where SMD components are more. Where there are a small number of THT components, wave soldering is recommended.

It is important to choose the right Printed Circuit Board Assembly (PCBA), USA who is technically sound and aware of all these nuances to do justice to your project.

Technotronix offers professional PCB Assembly services with 4o years of expertise. Our accurate PCB assembly process meets the quality standards, including ISO-9001:2015, RoHS, and more. You can rely on our PCB design tools that, in turn, lead to that perfect PCB Assembly. Our superior engineering capabilities mean that each board matches your exact requirements and technical specifications. In case if you have any questions, please feel free to contact us via email at sales@technotronix.us

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Top factors that determine the cost of Multilayer PCB Assembly!

By | Date posted: | Last updated: November 21, 2020
Multilayer PCB Assembly

The use of multilayer PCBs has become ubiquitous with several industries employing complex PCBs in increasingly miniaturized products. There are a number of factors, however, that determine the cost of a multilayer PCBs. Here is a quick overview:

Choice of material

The material used to fabricate the board has an obvious bearing on its costs. In making the choice of material for the PCB boards you need to take into account several factors such as:

  • Do you need the board to withstand high operating temperature? For boards that need to work in high-temperature operating conditions, what you need are boards which have copper clad laminate (CCL) and PP materials with high glass transition temperature. With low Tg material you stand the risk of the resin being de-laminated and thereby the electrical connectivity to be broken when the temperature rises.
  • Another major factor to watch out for is the signal performance. The choice of material is thus determined by whether the material will facilitate uninterrupted electrical signals.
  • Mechanical properties of the board are also key in order to ensure that the board can withstand any foreseeable mechanical stresses and strains.

Size of PCB

The dimensions of the PCB are also a determinant of its cost. The base material is often charged by dimension so large PCBs will come at a certain cost. This does not however mean that the standard rule of the smaller the PCB the cheaper it will be, will apply. This is because in small PCBs the routing time as well as labour involved may be intensive. The size of the PCB along with the process time involved, thus impacts cost.

PCB Layer Count

Another major determinant of cost is of course, the number of layers. If you are talking of a double-sided PCB board, for example, you are talking of the fact that there is no need for copper foil lamination and that there aren’t added layers that need processing. As a thumb rule, therefore, the greater the number of layers, the more resources as well as time is required for the manufacturing process and hence the greater the cost.

Surface Finish

The choice of surface finish also impacts the cost of multilayer PCB fabrication. Certain finishes are known for their quality and longer shelf life and obviously come with an added cost. For example, if you opt for HASL surface finish, the cost is low. By contrast, ENIG finish comes with a slightly higher cost. When it comes to HDI PCB designs, there could oftentimes be the need to use a mix of finishes, which in turn could have an impact on costs.

Type of hole and density

The price of multilayer PCB fabrication is a function of the following:

  • Size of hole

  • Its density

  • Hole type

When it comes to the size of the hole, the standard aspect ratio to be followed is 8:1, if there is a change in the hole size, it means that there is the need to use customized tools to meet your bespoke requirements, which will come at an added cost. Similarly, while a hole density of less than 120Kpcs/sqm is normal, any change in that will once again come at an added cost. Similarly a standard thru-hole comes at a standard cost, however, if the board requires any blind and buried vias, the cost tends to go up.

Trace Width and Spacing

On a multi layered board to avoid overheating, there needs to be sufficient trace width. Engineers could therefore look at there could be a need of enlarging the trace width or adding extra solder, both of which add to the cost in terms of material as well as the work involved.

Thickness of PCB

Thicker material typically is costlier to produce, laminate as well as turn into a PCB. Add to this if the design is complex, the cost goes up. Another area that impacts price is the aspect ratio.

Requirement of any special processes

In case there are any unique design elements and the need for any special processes, it has an implication on the cost. Some of the processes that could impact cost include impedance control, carbon ink, blind vias, edge plating, depth-control, halogen free material and more.

A detailed evaluation of the above parameters can help in effectively determining the cost of multilayer PCB fabrication.

The above Factors affect multilayer PCBs cost so, be careful while you take any budget decisions for your multilayer PCB assembly. We have over four decades of experience in providing innovative PCB Assembly services using modern technologies and the latest machinery. We are adhering to strict high-quality standards and compliant with the RoHS quality management system. If you are looking for progressive Multilayer PCBs, you are at the right place. All you need to do is to reach out to us and have complete peace of mind, which comes from knowing that the people manufacturing your product are experts in their domain! To know more, please contact us to get an effective Multilayer PCB!

Top Benefits of Contract Manufacturing PCB Assembly in USA!

By | Date posted: | Last updated: December 5, 2020
Contract Manufacturing PCB Assembly

Having an experienced third party contract PCB Manufacturing service is a source of major competitive advantage. While electronics manufacturers may have the ability to design boards and the skills to assemble the final product, they typically do that have the experience to manufacture boards. For them to get into board manufacturing would mean trying to reinvent the wheel. A contract PCB manufacturing service, on the other hand has a huge body of industry knowledge that you can benefit from. Besides some of the other advantages you can reap involve reduced overhead costs as well as the ability to focus on your core competencies.

Before we get into the details of the numerous advantages offered by contract PCB manufacturing, it will be worthwhile to get into some details of what third party contract manufacturing actually entails.

What exactly is third party contract manufacturing PCB assembly?

A third party or contract manufacturer, across industries, is one that builds products under the other company’s brand name. When it comes to PCB manufacturing, a contract manufacturer builds custom boards basis the designs of the company that has contracted its services. With the skill and expertise of the contract manufacturer, the electronics manufacturer tends to gain in terms of reliability as a PCB is imperative to the success of the final product.

Following are the advantages of Contract PCB Manufacturing service:

Makes the process easy

Building your own PCB comes with a wide range of difficulties including but not limited to:

  • Expenses involved in purchasing and maintain state-of-the-art equipment.
  • Having robust processes in place
  • Having to employ experienced and skilled staff who is capable of handling complex PCB fabrication & assembly.

On the other hand, with a contract manufacturer you will be assured of the fact that he has both the equipment and expertise required to deliver quality products. Importantly they have a lot of experience in making sure that your design can be manufactured efficiently. Additionally the experienced staff is fully equipped to handle boards that are multi layered and have high density of components. In a scenario where miniaturization is a growing trend, the importance of this cannot be overstated.

Product quality

For an electronics manufacturer, the quality of the boards is paramount as it impacts the quality of their final products as also their company reputation. With a PCB contract manufacturer, experienced engineers focus on the manufacturability of each design. Also, PCB contract manufacturers have a host of industry certifications and quality standards to live up to. All of this ensures that the quality of boards that you get live up to the latest industry standards.

Optimal Costs

With a contract manufacturer another big advantage you have is that they have a wide network of vendors. What this means, is that they can secure quality components at the best price. For components that aren’t readily available they are also trained to make alternate recommendations that will not come in the way of the quality of the product.

Capability to produce low volume PCB prototype

Oftentimes, you would want low volume prototypes designed, to be able to gauge at the final product, without investing in a full production run, just yet. With a contract manufacturer, USA, you have at your disposal the capability to get low volume production runs with the same unstinting focus on quality.

Quick turnaround time for PCB assembly

What a contract manufacturer also offers is quick turnaround time. With quick go-to-market being a significant source of competitive advantage, the importance of this cannot be overstated.

For an electronic manufacturer, therefore, trying to build the boards themselves can turn out to be a costly mistake. Not only will it add a whole lot of overheads to the operations, importantly even after that you cannot be sure of the quality of the boards. While you can replicate the machines, what will be hard to replicate is the body of experience that the contract manufacturer has. It is this experience that allows him to correct many mistakes early, which if detected after the production run can be really expensive. The expense isn’t in terms of money but can also be in terms of company reputation that is extremely hard earned.

Technotronix offer high quality and defect free PCB Assembly and PCB manufacturing services as per customer specification. We also offering dedicated SMT PCB Assembly, Prototype PCB Assembly, Led PCB Assembly, Overseas PCB Assembly, Mastering Mixed PCB Assembly and more services as per customer requirements and specification. In case if you have any questions, please feel free to contact us via email at sales@technotronix.us

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Top advantages of Turnkey PCB Assembly for entrepreneurs!

By | Date posted: | Last updated: November 11, 2020
Turnkey PCB Assembly

Simply put, turnkey PCB assembly refers to the PCB partner offering end-to-end services right from procurement of parts to shipping of the final finished product. From the point of view of sheer logistics, saving of time and energy, the importance of this service cannot be overstated. However, particularly for entrepreneurs the service is invaluable.
Here are some of the advantages of turnkey PCB assembly services that entrepreneurs can benefit from:

Product Quality

First up, as an entrepreneur what you are looking for is a high-quality PCB that can do justice to the final product or device that you are launching. There is no way you would want to sacrifice the quality of the boards, which in turn can cost you your reputation. With miniaturization ruling the roost, you particularly need an experienced vendor who can do justice to high-density boards. With turnkey PCB assembly you are assured of getting high-quality boards as the entire onus rests on the service provider. Not only do you not have to deal with multiple vendors, there is also the added advantage of there being no communication loss in dealing with multiple touch points.

PCB Prototypes

As an entrepreneur, odds are that you need product prototypes to be able to explore your idea before investing time and money in developing it as also to present a minimum viable product to investors. A big advantage that turnkey PCB Assembly, USA, offers is that it can identify any problems early. These may be by way of design concerns, which if spotted late can prove to be very costly. With turnkey services, not only do you stand to reap the advantages of correcting any mistake early, but also establishing design practices that can be a good benchmark for the future.

Saves Time

With a single vendor taking care of all issues, the production time is controlled. Firstly, you do not have to spend precious time hunting for components. The time thus saved, can be used in many other productive issues that need your attention. The time saving is also on account of the fact that you have a single point of contact. This means that you do not have to deal with the ripple effect of delays, which is typically the case when you deal with multiple vendors. Also, there is likely to be no generation loss in communication since you aren’t dealing with multiple stakeholders.

Cost efficient Turnkey PCB Assembly

What turnkey PCB also brings to the table is cost efficiency, which is extremely valuable for an entrepreneur. Should you decide to go the route of sourcing components on your own, for example, you are not likely to get the economies of scale that a turnkey PCB Assembly USA is likely to enjoy. You will also have to deal with individual shipping costs that may push your total cost, northwards.

What turnkey providers also help you with is efficient financial planning as they can offer you accurate quotes, promptly.

Custom PCBs

Contrary to popular belief, turnkey PCB assembly does not follow a cookie-cutter approach. Instead, turnkey assembly are well-poised to offer you products that are customized to your unique requirements.

Summing up
To sum up, entrepreneurs, therefore, have a lot to benefit from turnkey PCB services. Right from offering speed to optimal costs to custom products, a turnkey PCB assembly service can bring you complete peace of mind, as you know that a single vendor is fully accountable. That it also leaves you with the time and energy to deal with myriad issues in your entrepreneurial role, is an added perk! Whether you are an entrepreneur who is just starting out or someone who is scaling up operations, there is no way you would not want to make use of turnkey services.

At Technotronix, we have over 4 decades of experience in offering high-quality custom boards. Our state-of-the-art machinery and experienced manpower can offer you products that are way ahead of the curve. Additionally, we have a huge vendor network when it comes to sourcing components. What that means for you, is that we offer you high quality products with a quick turnaround time and at optimal costs. A range of clients across industries have gained a competitive edge with our turn key PCB Assembly, California with our consistent delivery of high-quality, on-time, price-competitive products. To know more, please explore our Turkey PCB Assembly!