PCB Blog - What is the PCB product assembly service?

PCB assembly refers to the process of assembling all electronic components (such as resistors), transistors, diodes, etc On the printed circuit board, the assembly method can be manual or mechanical. People often confuse PCB assembly with PCB manufacturing, as they involve completely different processes.

PCB products assembly service

Which industries require PCB manufacturing and assembly services?

Different types of industries and their demand for PCB manufacturing and assembly services. Many industries require PCB manufacturing and assembly services. PCB manufacturing and assembly services are widely used in fields such as electronics and automation. The following are some industries that require PCB manufacturing and assembly services.

Automobile

The automotive industry requires high-quality PCB design to reduce the time and cost of testing cars. They rely on flexible PCB manufacturing and assembly services or rigid flexible PCB manufacturing and assembly services to reduce the replacement cost of parts and vehicles upon arrival at the production line.

electronic product

The electronics industry uses PCB manufacturing and assembly services to produce various electronic products, including smartphones, computers, and household appliances such as washing machines and air conditioners.

Medical

The medical industry requires PCB manufacturing and assembly services for various purposes, including measuring blood pressure and other vital signs such as heart rate monitors. The industry also provides PCB manufacturing and assembly services for surgical equipment and medical diagnostic equipment.

space flight

The aerospace industry relies on PCB assembly services to develop circuits for components used in satellites, rockets, and aircraft, such as landing gear assembly lines, navigation systems, and aircraft instrument displays. Usually, PCBs are referred to as PWBs or printed circuit boards.

Agriculture

The agricultural industry uses PCB manufacturing and assembly services to develop machines for harvesting crops or managing livestock. PCB components are used in automatic milking machines and greenhouses for horticulture (planting plants) and hydroponics (planting soilless plants).

Mining

The mining industry relies on PCB manufacturing and assembly services for vehicles and equipment used in various stages of extracting natural resources (sand, minerals, oil, etc.). PCB manufacturing and assembly services are used for underground mining machines and pipelines for transporting oil or natural gas.

Building

The construction industry uses PCB manufacturing and assembly services to process steel and other building materials, such as concrete and ceramic tiles. Then these materials are made into objects with various functions, such as buildings, tanks, pipelines, or bridges.

Transport

The transportation industry utilizes PCB and assembly manufacturing services to meet its various forms of land, air, and sea travel. PCB manufacturing and assembly services are used to develop GPS systems for tracking aircraft in flight or ships at sea, as well as electronic components in cars and trucks for personal transportation.

PCB Product Assembly Technology

The advancement of electronic technology has brought more possibilities for PCB assembly There are three commonly used assembly techniques now, one is SMT (Surface Mount Technology), the second is THT (Through Hole Technology), and the third is a combination of the first two.

Surface Mount Technology

SMT assembly is mainly achieved by soldering surface mount devices (SMTs) onto printed circuit boards. Due to the small standard packaging of SMD components, the entire process must be carefully controlled to ensure high precision and appropriate temperature of the solder joints. Fortunately, SMT is a fully automated assembly technology that can automatically pick up individual components and place them on a PCB with extremely high accuracy.

Through-hole technology

THT is a more traditional PCB assembly technology where installers insert electronic components such as capacitors, coils, and large resistors and inductors into the circuit board through holes. Compared to SMT, the through-hole installation allows for the assembly of large components, providing stronger mechanical bonding, which is also more suitable for testing and prototype design.

Hybrid PCB assembly technology

Electronic products tend to be designed with smaller volumes and more functions, thus placing higher demands on PCB assembly. People need to assemble highly complex circuits in limited space, and it is difficult to achieve the expected results using only SMD or PTH. We need to combine SMT and THT technology. When using hybrid PCB assembly technology, appropriate adjustments must be made to simplify welding and assembly.

PCB assembly process

1. Solder paste printing

In the first step, the solder paste will be applied to the board The solder paste is gray and consists of tiny metal balls, with 96.5% confidence, 3% silver, and 0.5% copper, ensuring that it is used in a controlled amount and applied in the exact location On the PCB assembly line, the printed circuit board and solder template are fixed by mechanical fixtures and an accurate amount of solder paste is applied to the required area The machine applies the slurry onto the template until it evenly covers each open area Finally, when we remove the template, we can see that the solder paste remains in the correct position.

2. Handling

In the second step, we need to use a mounting machine that can automatically place surface mount components on printed circuit boards Currently, SMD components are widely used in various PCBs and can be efficiently assembled In the past, manual picking and placement were applied, and assembly personnel needed to pay great attention during this process to ensure that all components were placed in the correct position And automatic retrieval and placement are operated by working robots 24/7 without fatigue, which greatly improves productivity and reduces errors The machine uses a vacuum fixture to pick up printed circuit boards and then moves them to the pickup and placement station Then the robot places the PCB on the workstation, and the SMD components will be placed on top of the solder paste at the designated location.

3. reflow soldering

After taking and placing, the PCB assembly will be transferred to the reflow soldering process The circuit board will be transferred to a large reflux furnace through a conveyor belt The oven will heat the boar at high temperatures, usually around 250 degrees Celsius, to melt the solder in the solder paste When the heating process is completed, the circuit board will pass through an oven composed of a series of cooler heaters, which will help cool and solidify the melted solder During reflow soldering, we should pay attention to some special boards, such as double-sided printed circuit boards Each side of the double-sided printed circuit board needs to be stenciled and reflowed separately. Generally, the side with fewer components will be reflowed first, and then the other side.

4. Inspection

The assembled circuit board needs to undergo functional testing, and the reflow process may result in poor or even no connection Movement during reflow soldering can also cause a short circuit Therefore, inspection is a key step involved in the assembly process There are various methods for checking errors, among which manual inspection, X-ray testing, and automatic optical testing are commonly used Regular inspection can be carried out after reflow soldering, so any potential problems can be identified until PCB assembly enters the next process This type of inspection can help manufacturers save a lot of money because the earlier they discover problems, the earlier they solve them without wasting time, human resources, and materials.

5. Insertion of through-hole components

In addition to SMD components, some circuit boards may need to be assembled with other types of components, such as through holes or PTH components So how do you assemble these components? Excellent, the circuit board has electroplated holes that provide access for PCB components to transmit signals from one side of the board to the other Therefore, in this case, solder paste is feasible, so we need to use other welding methods to insert PTH components, such as manual welding and wave soldering.

6. Functional testing

In the final step, a final inspection will be conducted to test the functionality of PCBA, which we refer to as functional testing. This test will simulate the normal operation of the PCB and monitor the electrical characteristics of the PCB when the power and analog signals pass through the PCB to determine whether the PCBA is qualified.

PCB product assembly services are very suitable for various PCB designs, providing fast turnaround time and high-quality circuit boards. PCB product assembly services can help reduce costs.