The characteristics of selective welding process are studied by comparing with wave soldering. The most obvious difference between the two is that the lower part of the printed circuit board in wave soldering is completely immersed in the liquid solder.
The heat generated during the operation of electronic equipment makes the internal temperature of the equipment rise rapidly. If the heat is not distributed in time, the device will fail due to overheating.
In PCB proofing, temperature sensitive elements can limit the application of reflow soldering, whether in cartridge or SMD. Therefore, selective welding can be used after reflow welding in most applications.
Printed Circuit Board Quality Standards and Performance Specifications Series Manual. Includes the quality standards and performance specifications set by the Printed Circuit Board Association of America for all printed circuit boards.
What is printed circuit board DFM: Product Manufacturability Design for short DFM. It is a discipline that studies some design behavior rules of the relationship between the physical design of the product itself and the parts of the manufacturing system,
FPCS have many applications in a number of different fields. They are used in solar cells, mobile phones, vehicles and aircraft. Many of these applications require thin and durable flexible sheets, which can therefore withstand bending, folding or rolling
various components (chips, resistors, capacitors, inductors, plugs, fuses, etc.) will be welded or affixed to the PCB, so that it is together with the copper foil layer. To form a complete circuit.
PCB board test system will have a new design idea, the use of automatic test system based on USB bus and virtual instrument design idea, give full play to the role of the computer
Halogen-free PCB printed circuit boards have low water absorption and meet the requirements of environmental protection, in other performance can also meet the quality requirements of PCB board.
Circuit designers and technicians of products must master and follow PCBA manufacturability design procedures. Following PCBA manufacturability design procedure is the first prerequisite for product manufacturability design.
To summarize, the production process of a typical pcb factory is as follows: blanking → inner fabrication → pressing → drilling → copper plating → outer fabrication → soldering paint printing → text printing → surface treatment → contour processing.
Why is lead not allowed on printed boards, assembly processes and products? There are two reasons for this: first, lead is toxic and affects the environment; Second, leaded solder is not suitable for new assembly technology.
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