PCB Assembly Process: Everything You Need to Know

Introduction

If you want your printed circuit board (PCB) to succeed, you need to know how it will be assembled. The PCB assembly process may seem like a simple “hands-off” approach, but there are many ways that mistakes can happen at this stage.

The PCB assembly process is complex. It can vary in terms of the order. There are some fundamentals that apply to most cases. We will give you an overview of what the PCB assembly process looks like. It will also shed some light on how the industry came about and how it is changing.

PCB Assembly Process

What You Should Know about PCB Assembly Process?

The PCB assembly process is complex and involves many steps, but before you know how to do it, you need to understand what PCB assembly is. PCB stands for printed circuit board. A printed circuit board is a flat board that has electronic components attached to it. These electronic components include resistors, capacitors, transistors, diodes, and integrated circuits (IC).

The purpose of a printed circuit board is to connect all the different electrical components in an electronic device. For example, are as a computer or television set. The electronic components on the PCB are connected using copper tracks. This forms an electrical circuit. This allows electricity to flow from one component to another without being interrupted by other components in between them.

The most important part of any PCB assembly process is designing your own custom circuit boards. Using CAD software such as EagleCAD or KiCad before sending them out for manufacturing is best so that they meet your exact specifications when they come back from production.

You should also make sure that your design meets all industry standards. For it to be used with other systems within your company or industry without causing any problems with compatibility issues or power supply issues when installing new products into existing systems at different locations within your company’s warehouses or offices around the globe!

Types of PCB Assembly Process

3 Types of PCB Assembly Process

When you’re looking for a PCB assembly process, it’s important to know what you’re getting into. The whole process of making a PCB can be complicated and confusing, but if you know what to look for, you’ll be able to find the right fit for your needs.

There are three main types of PCB assembly processes. These are Thru-Hole Technology, Surface Mount Technology, and Mixed Technology Assembly Process. Each has its own benefits and drawbacks and will give your product a different look. Which one is right for you? Let’s take a closer look!

THT Assembly

Thru-Hole Technology Assembly Process

This technology refers to the way that components are connected to the PCB and soldered into place.

Thru-hole technology involves placing components on top of the board and then soldering them in place. The solder forms a mechanical bond between the two materials, allowing for a secure and stable connection. For this reason, through-hole technology is often used in applications where reliability is essential.

The most common types of through-hole components are resistors (both fixed and variable), transistors (NPN and PNP), diodes, capacitors, ICs (integrated circuits), LEDs (light emitting diodes), inductors (coils), transformers, fuses and relays (switches). Some boards also support through-hole devices called jumpers which allow you to change certain settings such as voltage levels or other parameters.

SMT Assembly

Surface Mount Technology Assembly Process

This assembly process is a popular choice for electronics manufacturers because it allows them to save money on materials and labor costs.

The process involves placing components onto the board as opposed to through-hole mounting, which involves inserting leads into holes in the board. The holes are often smaller than the leads, which makes this type of mounting cheaper and easier than through-hole mounting.

This type of assembly can be done manually or with an automated machine. Manual assembly requires more skill on the part of the assembler, but automated systems allow for higher production rates.

Mixed Technology Assembly

Mixed Technology Assembly Process

This is a process that involves the use of both SMT and Through-Hole technologies. The main advantage of this method is that it enables you to assemble very small components, such as ICs and resistors, using SMT technology, while keeping larger components like connectors and transformers in place via Through-Hole assembly.

The mixed technology assembly process gives you more flexibility in what kinds of boards you can create, but it does come with some drawbacks. The first drawback is that because you’re combining different types of PCBs, the design needs to be flexible enough to accommodate all of them. This means that it’s harder to make sure your product will work as intended if you’re using a mixed technology assembly process.

Steps in PCB Assembly Process

8 Major Steps in PCB Assembly Process

There are eight major steps in the PCB assembly process. If you are faced with cost issues, taking shortcuts may not be one that is practical. If you can afford it and want to get the most out of your product, then these are 8 steps in PCB assembly process that can help you make sure that there is no room for mistakes.

Material Preparation and Examination

This step is used to evaluate the materials that are going to be used for the PCBs. The materials are examined for their quality, then they are prepared for use. The materials should be checked for any defects and if there are any, then they must be removed from use.

Component Placement

The goal of this step is to ensure that all electronic components are properly placed on the PCB and are connected to each other correctly. Components are then placed on top of the stencil and connected with conductive adhesive tape.

Wave Soldering

A method of soldering that uses heat, a flux and pressure to join electronic components. It is used to solder the leads onto the body of an electronic component.

The wires are attached with a wave soldering machine which moves through the components in a wave-like motion. The heat from the machine melts the solder and allows it to flow around the wire and into all corners of the component before cooling back down again.

Stencil Preparation

The stencil is typically made from a paper- or plastic-like material and has openings at each of the desired solder points on the PCB. If you do not have a properly prepared stencil, then you may end up with inconsistent results. This will affect the PCB during actual assembly and could potentially damage your product.

Solder Paste Stenciling

A process by which two or more conductive materials are joined together to form a single interconnection. The most common solder joints are through-hole, surface mount, and wave soldering.

Through-hole soldering involves inserting a component into an aperture in the PCB and then soldering it to pads at opposite edges of the hole. This produces a permanent joint that cannot be easily disassembled. On surface mount technology, the components may then be placed directly onto the surface of the board or onto a substrate such as ceramic or plastic.

SMC/ THC Placement

In this step, the components are placed on the circuit board. The parts are placed on the board in a way that allows for easy access to them when soldering them. This is done by placing the component so that its legs or leads are pointing up and down, or sideways, which will allow for easy access once they have been soldered.

The parts can be placed manually or automatically with the use of automated placement equipment.

In order to prevent damage during placement and soldering, it’s important that all components be placed with minimum spacing between them to avoid short circuits and overheating issues.

Reflow Soldering

In the PCB assembly process, reflow soldering occurs when the PCB is heated to an extremely high temperature in order to melt the solder paste and bind it to the copper traces of the PCB. The purpose of reflow soldering is to create stronger joints between conductive traces on a PCB and resistors or other components attached to those traces.

PCB Inspection

Inspection

The PCB assembly process is a complex sequence of steps. It must be performed in order for the end product to be successful. A defect can occur at any point during this process, and if it does, it could result in faulty components or even a complete failure of the circuit board.

Inspection is the most important part of this process because it allows manufacturers to catch defects before they become part of the final product. This will help reduce costs by reducing waste and improving efficiency.

There are also three types of inspection. Each PCB go through this types of inspection to ensure quality:

Manual Inspection

The manual inspection step of the PCB assembly process is exactly what it sounds like. A human being inspects the printed circuit board and compares it to the original design. The inspector looks for any issues that might have arisen during the production process. Examples are loose components or incorrect placement. If any problems are found, they are fixed by hand before moving on to the next step in the assembly process.

Optical Inspection

After the components have been soldered to the PCB, they are inspected to ensure that they are correctly aligned and that all solder joints are strong and secure. The optical inspection equipment used for this step. This is typically an LED microscope with high magnification capabilities and a bright light source

The glass slides used to hold each circuit board must be clean and free of any contaminants. This is in order to ensure that the microscope’s image quality is not affected. The technician who performs this task uses tweezers to handle each board. They ensure that he does not touch any of its surfaces with his hands or contaminate them with oils from his skin.

X-ray Inspection

This inspection is done after all the components are soldered, and before any other process takes place.

The x-ray machine sends rays into the PCB assembly. These rays bounce off of the internal components and give an image of them on a monitor. An x-ray technician can then see any defects in the assembly, such as missing or misplaced parts.

If there are no defects found in this step, then it means that all soldering has been done correctly. It means all components are secure in their positions on the board.

What You Need to Consider Before the PCB Assembly

PCB assembly is a complex process that requires a lot of work, attention to detail and planning. Before you begin the assembly process, there are several things you need to consider.

Component Layout

The component layout is one of the most important aspects of PCB assembly. This is because the placement of components on the PCB can have a significant impact on the performance, reliability, and cost of your final product. If you don’t take the time to carefully consider where each component goes on your board, then there’s a good chance that something won’t work correctly or will fail prematurely.

Hole and Vias Spacing

When you’re assembling your PCB, you’ll need to decide how far apart the holes and vias will be. This is important because it determines the spacing of your components, which is important for both soldering and EMI shielding. The closer together the holes are, the easier it is to solder components into place on the board. However, this also means that the EMI shielding will be weaker. The farther apart your holes are, the stronger your EMI shielding will be, but this also means that it will take longer to solder each component into place.

Copper Pads

These are the foundation of your circuit, so they should be carefully designed and placed. Copper pads allow connections between components and help conduct electricity throughout your circuit. If a copper pad is too small or too far apart, it will not be able to conduct enough electricity to operate properly. If it’s too large or too close together, then there is a chance that more than one component will accidentally connect together and cause problems with your circuit.

Conclusion

In the end, if you’re planning to rework PCBs then it is highly advised to pick up a PCB manufacturing company. The ones you choose should not cheap out on your circuit board assembly work. The job of a PCB designer is not just about designing awesome circuit boards. They also ensure that they meet the specifications of their clients and can easily be fitted into the final product.