he word assembly means to gather or integrate something onto some platform. In the terms of electronics, electronic assembly means integrating or assembling electronic circuits into a single enclosure or to solder electronic components onto a PCB. Within a printed circuit board Electronic PCB assembly or production or manufacturing process there are several individual stages. However, they all must work together to form an integrated overall process. Each stage of assembly and production must be compatible with the next, and there must be feedback from the output to the input to ensure that the highest quality is maintained. In this way, any problems are detected quickly and the process can be adjusted accordingly.
Electronic PCB assembly Types:
Automated PCBA:
Many companies provide services in electronic assembly work. The most popular domain is PCBA (PCB Assembly china). This work requires a very simple yet expensive setup that includes automated machines like pick and place robots and soldering machines that are used to do PCBA. This automated assembly will save a lot of time and effort and is very useful in batch/bulk manufacturing. The major factors that contribute to higher costs are
- 1. Pick and Place SMT machine programming
- 2. Process of reflow soldering
- 3. Solder stencil making
- 4. Cleaning of Solder flux
- 5. Different QC inspections
- 6. Labor Charges
- These factors contribute to higher prices, but the process is speedy and highly suitable for bulk electronic assembly / PCB Assembly. The automated SMT components assembly price is directly proportional to the BOM (Bill of Material) lines. The automated electronic component assembly cost also depends on the size and type of the components. For example, BGA and QFN, lead-less components will increase PCB assembly cost, 0201 packages of resistors, capacitors will also increase assembly cost.
- The double-sided electronic circuit boards, means boards having components on both sides of PCB, have a higher cost in assembly then single-sided boards.
The manual PCB assembly includes hand soldering and de-soldering. This method is good when you need some customized product assembly and you need only a few prototypes. In this case, there is no need for a CAD file for automated placement of components, you just place components by hand and solder them. To de-solder, you just need a solder sucker and hot air gun to pull components out from the PCB. This is an advantage in manual PCBA that you can de-solder components at will. This is also useful in electronic circuit boards repairs and service. The BGA and QFN components soldering is done manually to ensure neat work. Hot air guns and solder balls are used in hand soldering of these IC packages.
Prototyping, Modular, Product Assembly:
In this type of assembly, the PCBs stuffed with components can be assembled in an enclosure made of plastic, sheet metal, or similar material. For this purpose, electronic assembly companies use 3D modeling software like Solid Works, PRO-E, and AUTOCAD to design enclosures. This software can also design the wiring/harness of the entire product. For example, in Servo Drives, there is a separate PCB for power supply, relay board, microprocessor board, and signal conditioning board. So these companies fabricate the enclosure and then assemble the stuffed PCBs in and interconnect all wires and harness and finally test the product and deliver.
Basic sequence & requirements of the Electronic PCB assembly
Turnkey assembly sequence and principle
The general principle of the turnkey assembly installation is as below:
- Light, then heavy
- Small, then large
- Riveted, then installed
- Mounted, then welded
- Inside, then install outside
- From the bottom, then to the top
- From flat part and then to the high part
- Fragile and easily damaged are the final installation
- The previous process shall not affect the next process
Electronic assembly process:
The various stages in the PCB assembly process include adding solder paste to the board, picking and place of the components, soldering, inspection, and test. All these processes are required and need to be monitored to ensure that product of the highest quality is produced. The PCB assembly process described below assumes that surface mount components are being used as virtually all PCB assembly these days uses surface mount technology.
PCB Assembly Process
1. The basic requirement for assembly preparation is to ensure sufficient quantity and matching of components of PCBs and components. And the quality must be qualified.
2. The processing and fabrication of the connection cable are mainly based on the design documents, processing all kinds of connecting cable used in the whole assembly process to meet the production process requirements.
3. PCBA assembly is mainly to install capacitors, resistors, transistors, integrated circuits, and other electronic components on the PCB board according to the requirements of the design documents, which is the basis for manufacturing turnkey electronic products.
4. Unit assembly is based on PCB assembly, combining PCB components through the interface and connecting cable into units or modules with specific functions.
5. The turnkey assembly is based on the unit assembly, and the various unit components that make up the electronic product are installed in a unified cabinet, cabinet, or other carriers, and finally, become a complete electronic product.
6. Turnkey assembly debugging and testing. Commissioning and testing is must after turnkey assembly. The turnkey assembly debugging mainly includes two parts of adjustment and test.
7. Adjustment is a working process to adjust the adjustable part of the electronics products to enable it can complete the normal working. This test is a comprehensive test of the function and performance of the assembled machine. The test can achieve the predetermined technical indicators and whether the predetermined function can be achieved.
8. The final inspection is the finishing part of the assembly of the entire electronic product. It is mainly to carry out a comprehensive inspection of all aspects of the adjusted turnkey assembly to detect whether the product is qualified.
How to Choose Electronic PCB assembly Companies:
Most of the companies that are electronic assembly companies deal in bulk quantities of production. Choosing an Electronic PCB assembly company is not difficult if you know your requirements. You should get all services from a single supplier/company that provides, PCB fabrication, PCB assembly, product assembly, and delivery of the product at the customer location.
So to choose an Electronic PCB assembly company of your requirements, this should have
1- A company that provides the best quote in terms of “quantity” required and “price”
2- The company should have the least “MOQ” (Minimum Order Quantity)
3- If the customer wants large quantities, then a larger MOQ is also good. Usually, 500,1000,10,000 quantities are offer by bulk product assembly companies.
4- The company should have “least lead” time
5- The “quality” of the product matters a lot, but quality can only be observed when you receive your consignment. If you experience a good quality of PCBA or electronic assembly of products then you can place a “repeat order”. This means you can again hire the same company for the same product and quantity.
6- Online websites like Alibaba, Aliexpress, HKTDC, Made in China, eBay, Amazon have the option to search for online suppliers and manufacturers. The manufacturer is the one is that has its factory and production facility and also has its warehouse. On the other hand, the supplier is the one that picks the products from other factories, and keeps its commission, and sells at a higher price.
7- You should approach directly to the manufacturer rather than the supplier or retailers
8- You should check for feedback and ratings given to suppliers/manufacturers from other clients.
9- You should read reviews given online to suppliers/manufacturers
10- You should also watch for the snapshots of the products, so you can have the idea to visually check the quality of a product. This is not a guarantee that what you see is exactly what you get, but you should check these snapshots and compare them with other suppliers to filter those suppliers who do not satisfy your needs.
11- A supplier with a money-back guarantee is always good
12- Avoid free delivery suppliers. Because this will take a lot of time maybe around 60 days to shipment reach your location. Or maybe it never reaches. This is usual for free shipment. Select suppliers that support DHL or EMS delivery
13- Select those suppliers/manufacturers whose response and customer support is good
14- Select those suppliers/manufacturers who have the most experience and awards on online stores like mentioned in Sr#06
15- Nowadays most of the suppliers and manufacturers' factories and warehouses are in China. So they have cheap labor and low-cost products that can meet your requirements.
Why Europe PCB is the top priority for Electronic PCB assembly?
The PCB assembly process for the manufacture of loaded printed circuit boards has been considerably simplified in this overview. The PCB assembly and production processes are generally optimize to ensure very low levels of defects, and in this way produce the highest quality product. Because of the number of components and solder joints in today's products and the very high demands placed on quality, the operation of this process is critical to the success of the products that are manufacture. Europe PCB is the the top choice for electronic PCB assembly for years.
