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Electronic Assembly

What is the turnkey(box build, final assembly) assembly?

The turnkey(box build, final assembly) assembly is based on the design documents – Electronic Assembly. According to the technical procedures and specific requirements of the process documents, various electronic components and electromechanical components are assembled on the circuit board and carry out various tests, such as AOI, ICT, FCT, etc. Then, the tested PCBA board and the casing (generally divided into plastic and metal casings) together form a complete electronic product with certain functions.

The turnkey assembly process has differed according to the complexity of the product and the capacity, etc. But overall, there processing included assembly preparation, connective cable processing, PCBA assembly, component assembly, turnkey machine testing, turnkey assembly, inspection, package, etc.


Electronic 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 are required 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 products. It is mainly to carry out a comprehensive inspection of all aspects of the adjusted turnkey assembly to detect whether the product is a qualified product.


Basic sequence & requirements of the turnkey 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

Basic requirements for turnkey assembly:

1. The fittings (include components & assembly unit) that have not passed the inspection shall not be installed, and the assembled parts that have passed the inspection shall be kept clean.

2. Read the process documents and design documents carefully and strictly abide by the technical procedures. The completed turnkey assembly shall meet the requirements of drawings and technical documents.

3. Strictly follow the general sequence of assembly, prevent the order of the front and back from being reversed, and pay attention to the process connection between the front and the back.

4. Do not damage the components during the assembly process, to avoid damage to the coating on the machine case and components, so as not to damage the insulation performance.

5. Requires proficiency in operational skills, quality assurance, and strict implementation of inspection, mutual inspection, and full-time inspection.