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Some background and information on industry terminology, more detailed information on some of the applications and solutions we have to offer

PCB Assembly: A Complete Guide

PCB (Printed Circuit Board) assembly is the process of attaching electronic components to a PCB to create a functional electronic device. It is a crucial step in the production of electronic devices and can make or break the performance of the final product. In this article, we will provide a complete guide to PCB assembly, including the different types of assembly, the components used, and the assembly process.

Types of PCB Assembly

There are two main types of PCB assembly: through-hole and surface mount. Through-hole assembly involves inserting the leads of electronic components through holes drilled into the PCB, then soldering the components to the board. Surface mount assembly involves attaching components to the surface of the PCB using small metal pads and solder paste.

Through-hole assembly is the older method of PCB assembly, and it is still used in some applications where large components and high power handling are required. However, surface mount assembly has become the standard in most applications due to its smaller size, lower cost, and increased reliability.

Components Used in PCB Assembly

There are a wide variety of electronic components that are used in PCB assembly.

Here are some of the most common:

Resistors: These components limit the flow of electrical current in a circuit.

Capacitors: These components store electrical charge and release it when needed.

Diodes: These components allow electrical current to flow in one direction only.

Transistors: These components act as switches or amplifiers in electronic circuits.

Integrated circuits: These components contain multiple electronic components, such as transistors and resistors, in a single package.

Assembly Process

The PCB assembly process involves several steps:

Solder paste application: Solder paste is applied to the surface of the PCB where the components will be placed.

Component placement: Components are placed onto the PCB by machine or by hand.

Reflow soldering: The PCB is heated to a high temperature, causing the solder paste to melt and create a connection between the components and the PCB.

Inspection: The assembled PCB is inspected for any defects or issues.

Testing: The assembled PCB is tested to ensure that it functions properly.


PCB assembly is a crucial step in the production of electronic devices. Through-hole and surface mount assembly are the two main types of assembly, and a wide variety of electronic components are used in the process. The assembly process involves several steps, including solder paste application, component placement, reflow soldering, inspection, and testing. By understanding the PCB assembly process, you can ensure that your electronic devices are produced to the highest quality standards.


Industry Terms

Here are some of the industry terminologies, buzz words and abbreviations that might help you out.



A contract electronics manufacturer is a company that provides a range of services related to the design, development, and manufacturing of electronic products on a contract basis. CEMs offer a wide range of services to their clients, which can include designing and prototyping electronic products, sourcing components, manufacturing electronic products, and providing logistics and after-sales support.



Printed Circuit Board," is a board made of insulating material such as fiberglass, plastic or ceramic, that has conductive pathways etched onto its surface to connect various electronic components. PCBs are used in virtually all electronic devices, from simple toys to complex computers and medical equipment.

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"Electronic Manufacturing Services." EMS companies provide a range of manufacturing services to other companies that design and sell electronic products, but may not have the necessary manufacturing capabilities. EMS companies offer services such as design, prototyping, assembly, testing, and logistics management.

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A Bill of Materials is a list of all the components, parts, raw materials, and subassemblies required to manufacture a product. The BOM provides a detailed list of all the items needed to produce the final product, including part numbers, descriptions, and quantities required for each item.

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"Original Equipment Manufacturer." An OEM is a company that produces components or parts that are used in other companies' products. The OEM company produces parts or components that are then sold to other companies, which integrate them into their own products.



Request for Quotation." An RFQ is a document used in procurement to request pricing and other information from potential suppliers for a specific product or service. The RFQ typically includes detailed specifications of the product or service being requested, as well as other requirements, such as delivery time, payment terms, and quality standards.


Vapour Phase Reflow

Vapour phase reflow is a soldering process that uses a heat transfer medium to reflow the solder on a printed circuit board (PCB). Here are some reasons why you might choose to use vapour phase reflow over other soldering processes:

Consistency: Vapour phase reflow provides consistent heating and cooling of the PCB and solder, ensuring that the solder joints are of high quality and free from defects.

High reliability: Vapour phase reflow can produce solder joints with high reliability due to the uniform heating and cooling of the PCB and solder. This results in strong, consistent solder joints that are resistant to thermal stress and vibration.

Low voiding: Vapour phase reflow can help reduce the occurrence of voids in solder joints. The heat transfer medium used in this process can penetrate small gaps and voids, leading to better wetting and bonding of the solder to the PCB.

Environmentally friendly: Vapour phase reflow is an environmentally friendly soldering process. The heat transfer medium used is non-toxic and non-flammable, and there is no need for flux. Additionally, the process has low energy consumption, which reduces the carbon footprint of the manufacturing process.

Suitable for complex PCBs: Vapour phase reflow is well-suited for soldering complex PCBs with fine-pitch components and high-density circuitry. The process provides uniform heating and cooling, which ensures that all components on the PCB are heated and soldered evenly.

Cost-effective: Although the initial investment in vapour phase reflow equipment may be higher than other soldering processes, it can be more cost-effective in the long run due to the high reliability and consistency of the process, which can reduce the need for repairs or rework.

In summary, vapour phase reflow can provide high reliability, low voiding, and consistent solder joints, making it a suitable choice for complex PCBs. The process is also environmentally friendly and cost-effective, making it an attractive option for many manufacturers.

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