Production Process 1: Pre-engineering| Multi-layer HDI PCB Manufacturing Process
All pcb orders need to go through the engineering department before being scheduled for production.
What the engineering department does to ensure the smooth production?
A. Gerber files Review
After customers upload the Gerber files, the engineering department will first pre-review them. The contents reviewed generally include:
01) Whether the design files are complete.
① A complete PCB files should includes:
Board outline
Bottom copper
Bottom silkscreen
Bottom solder mask
Fab drawing
Inner layers
NC drill
Top copper
Top silkscreen
Top solder mask
② Clear and complete PCB requirements information(in gerber files or in separate files are all ok for us)
Layers
Material, TG value, TD value…
2 sides or single side need soldermask/silkscreen, what the soldermask/silkscreen color each side, how thickness the soldermask should be
Hole copper thickness
Quality standard request: IPC Class II or IPC Class III
Hole size or outline tolerance
Stack up
Others
02) Other issues, such as whether the circuit design is reasonable; whether there is any requirement beyond our capability.
B. BOM Files Review
If you want us assembly PCB boards for you too, then full files:Gerber Files+BOM File+Centroid File（other names maybe:aka Insertion, Pick-N-Place, or XY Data）should all included and provided to us when you order.
Click here to check Template-for-PCBA-Quotation
① Gerber Files, Please include all the layers files (copper, soldermask, silkscreen, solder paste, drill, outline).
② BOM file should clearly and full description of every kind of component, need at least below items:
Manufacturer Part Number
Manufacturer or Brand
Specific description of components parameters and specification, including such as voltage, resistance, capacitance etc
Location Number according to PCB silkscreen file
Quantity
③ Centroid File, also known as pick and place file. It should include component locations, rotations and reference designators.
C. Deal with Gerber Files
When making sure the files are complete and basically ok, engineers start to make WF and send out EQ to communicate with customers.
1) (Engineering Question) EQ Communication, Working File(WF) and waiting for customer confirmation if customer request
WF Making:
The information in the Gerber Files can’t be directly input to the corresponding machines for various processing. WF is then used to make compensation,optimization and panelization etc works to gerber files customers designed according to our factory actual production equipment, processes and technology. Such as in gerber file, customer request finished hole size 1.0mm, when making working file, our engineers will enlarge to 1.1mm. Using 1.1mm drill bit, adding copper plated, the finished hole size fits into 1.0mm; such as panelization, in order to fit equipment actual size, we have to panelize smaller size PCB in customer gerber files to bigger size, and add aided tooling edges and tooling holes for alignment and fixed onto equipment during production.
EQ communication:
Engineers will read the Gerber files in details, they will send an EQ to the customer if there is any doubtful point. For example, if the laminate structure provided by the customer is asymmetric which may lead to board wrap and affect the assembly quality, then they will suggest the client to modify it into a symmetrical one.
Click here to check Common PCB EQ Examples
2) Manufacturing Instruction(MI) Preparing, Production Drawing and Process Card
Each PCB order is prepared with a complete MI, which contains detailed instructions for each process from board cutting to packaging. In addition to the MI, a production drawing and the process card also assist PCB production together. The production drawing is a special instruction for the important contents of the design files, include external dimensions drilling requirements, circuits, soldermask, silkscreen, etc. Process cards are mainly used to track the warehousing receipt, quantity and acceptance of each production process to endure that each step is in order and can be accurately traced in case of problems.
