What design files are included in SMT PCBA components

What design files are included in SMT PCBA components
Some companies do not manage their files well Even the most basic circuit board (PCB) files are missing.  The following introduces the basic files that should be available for general Circuit board assembly (PCBs) transfer
1. Gerber file or PCB CAD file Gerber file
Gerber archives are the most basic PCB manufacturing archives. After PCB factories receive Gerber files and import them into CAM software, they can provide production data for each PCB process. Gerber data can also provide image data for specific devices, such as automatic optical inspection equipment (AOI), and can also be used to define the basis of PCB steel plate aperture (aperture).
2. Fab drawing (manufacturing standard)
Wafer Factory Drawings
This specification usually requires the PCB manufacturer to complete the circuit board. The above contents usually include the following information. This specification is usually used as the inspection basis by the circuit board assembly plant when inspecting incoming materials:
The color of the insulating ink. It is usually green, but also black and red.
Screen printing ink color. It is generally white, but also yellow, and other colors are rare.
Surface treatment of printed circuit board, such as ENIG, HASL, OSP... wait. Some ENIGs also specify the thickness of gold and nickel layers, and some even specify the thickness of copper foil.

The substrate grade of the circuit board. Current circuit boards are divided into lead-free and lead-free processes. The lead-free process requires relatively high temperature resistance. If necessary, it is better to specify Tg value (lead-free 150C or higher) and Td value (lead-free 325C) of FR4 substrate. Z-axis expansion coefficient (300 ppm/degree or less).
Power efficiency of copper foil. Especially high-frequency products.
V-cut and additional machining or drilling information.
Puzzle style and size.
3. Panel drawing (jigsaw puzzle/connecting plate specification)
Coupling specification
The Gerber file above only defines the data of single chip PCB. However, in order to improve the utilization rate of the circuit board and the efficiency of the manufacturer, the actual output of the circuit board is designed by the board/connecting board. The shape, style and size of the board will affect the design of the following tools, and different jigsaw puzzle methods may even make the original tools unusable:
Steel plate (sample)
Vacuum block
Part visual inspection template (visual inspection template)
MDA (Manufacturing Defect Analyzer) or ICT (Online Tester) test fixture
FVT (functional verification tester, functional test fixture)
When transferring between different production lines and different factories, remember to use the original jigsaw puzzle style. If the original file does not define a puzzle style, you can request it from the original Circuit board manufacturer and standardize it.
4. Placement Component X-Y table (XY coordinates of SMT parts)
XY coordinate of SMT part
The SMT printer determines the position of the part to be placed on the circuit board according to X, and the user-defined Y coordinate axis Of course, there are other parameters (Z axis, rotation) to form the SMT printing machine As long as PCB designers can generate X and Y table of parts through PCB CAD, it can greatly reduce SMT engineers' programming
If it is impossible to generate X and Y coordinate tables from PCB CAD, you can still use the traditional method, use the projector to slowly measure part by part, or open the Gerger file and measure on the computer. However, no matter which method is used to measure the results, it is actually necessary to fine tune the SMT machine to match the actual coordinates.
5. Readable drawing file (readable circuit board layer)
Readable circuit board layer
Most people may not be able to read Gerber's archives directly. Normally, we will output each layer of PCB to a readable PDF file, including solder paste layer, screen layer, mask layer and various circuit layers.