Here you'll find insights into PCB design, tech trends, assembly issues, and trending topics
in the general news media as they relate to printed circuit board technology.
As experts in the manufacture and assembly of printed circuit boards, we work to make our blog a helpful resource on PCB topics and the industries that we work with, including automotive, consumer electronics, aerospace and many more.
Impedance PCB final test eligibility criteria
Downstream operators usually require PCB manufacturers to do 100% electrical testing, so they will agree with PCB manufacturers on test conditions and test methods. Therefore, both parties will clearly define the following:
As automated test equipment becomes part of the overall electronics assembly process, DFT must include not only traditional hardware usage issues, but also knowledge of test equipment diagnostic capabilities.
The DFT team should be aware of the existing testing strategy. As OEMs turn to relying on more and more CMs, the equipment used varies from plant to plant. Without a clear understanding of the manufacturer's process, too many or too few tests may be used. Existing test methods include:
The schematic design software will be available in ORCAD. The supported Netlist is much more than the industry standard.
Design requirements: The designer must read the schematic diagram in detail, fully communicate with the project engineer, understand the circuit architecture, understand the working principle of the circuit, and clearly understand the layout and routing requirements of key signals.
After the following procedures, the finishing work shall be undertaken by the operator responsible for PCB board testing and repair, unless otherwise arranged. The final installer shall be responsible for reviewing and correcting the reinstallation.
Remarks: The grinding process between silk screen and solder mask may be omitted. It can be soldered first and then screen printed, depending on the substrate.
PCB material are divided into: 94HB, fireproof board (94VO, FR-1, FR-2), semi-glass (22F, CEM-1, CEM-3), and full glass (FR-4).
Via is one of the important components of a multi-layer PCB. The cost of drilling is usually 30% to 40% of the cost of PCB board. Simply put, each hole in the PCB can be called a via.
The film consists of a protective film, an emulsion layer, a bonding film, a film base and an antihalation layer. The main components are silver salt photosensitive materials, gelatin and pigments. Under the action of light, the silver salt can be reduced to the center of the silver core, but it is not dissolved in water. Therefore, it can be suspended in a gelatin state and coated on the substrate. The emulsion also contains a pigment to sensitize. The exposed film is then obtained by actinic action.
The process is as shown below: (PCB/LCD design)-->(CAM system)-->(Gerber file)
Computer-aided manufacturing technology, the English name is Computer Aided Manufacturing, referred to as CAM, is an advanced technology that is controlled by computer control. The development of computer technology and the emergence of laser plotters have led to the use of PCB-assisted manufacturing technology. Various CAM systems can generally process the gerber data (Gerber data), eliminate various defects in the design, make the design easier to produce, and greatly improve the production quality.
For the production of PCB printed boards, because many designers do not understand the production process of the circuit board, the circuit diagram of the design is only the most basic circuit diagram, and can not be directly used for production. Therefore, it is necessary to modify and edit the line file before actual production. It is not only necessary to produce a film map that can be suitable for the production process of the factory, but also to make corresponding punching data, mold opening data, and other data useful for production. It is directly related to various production projects in the future. These require engineers and technicians to understand the necessary production processes, and at the same time master the relevant software production, including common circuit design software such as: Protel, Pads2000, Autocad, etc., should be familiar with the necessary CAM software such as: View2001, CAM350; GCCAM Etc., CAM should include PCB design inputs, which can edit, correct, repair, and imprint circuit graphics, use disk as the dielectric material, and output automated data for ray mapping, drilling, and inspection.
With the development of the electronics industry, the requirements for printed boards are getting higher and higher. The high density of the printed board design, the thin wire, the small aperture tend to be faster and faster, and the production process of the printed board is more and more perfect.
At first glance, the PCB is similar in appearance regardless of its inherent quality. It is through the surface that we see the differences that are critical to the durability and functionality of the PCB throughout its lifetime.
It can be classified according to PCB use, substrate type, structure, etc., and is generally divided by PCB structure.
Basic grounding method: There are three basic grounding methods in electronic equipment: single-point grounding, multi-point grounding, and floating ground.
The so-called copper coating is to use the unused space on the PCB as the reference surface, and then fill it with solid copper. These copper areas are also called copper filling.
Eight Principles of PCB Design
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