One, introduction to PCB proofing
1.PCB proofing definition
PCB proofing refers to the trial production of printed circuit boards before mass production. The main applICation is the process of SMAll batch trial production to the factory after the electronic engineer presets the circuit and completes the PCB Layout, that is, PCB proofing. General engineers in the product presets have not completed explicit recognition and complete testing, are calLED PCB proofing. In popular terms, the door is to do samples; PCB proofing is to make a physical object of the preset PCB schematic diagram, which is a product taste test before batch production. A PCB project needs to involve many items, a product if a link of the problem, it is easy to affect the degree of product development; The same is true for PCB board making. Generally, a project will be done, and the preset PCB will go to the sample factory for proofing, and several boards will be made for testing. If the test is passed, mass production can be carried out.
2.PCB proofing file
PCB proofing files generally cover pcb circuit board files or Gerber files, and plate making to explain - a few layers of board, material, pad process, ink color, whether there is impedance requirements do match.
3.PCB proofing cycle
Ordinary 7 days or so, can be expedited;
Single and double panel proofing 7 days delivery;
Four layers of board proofing 15 days delivery;
Mass production according to the labor capacity of each factory is not the same as the ordinary 20-30 days.
Two,PCB proofing to explain the project
Generally, it covers PCB single size, PCB joint size, PCB material number, number of doors, PCB board material, PCB board thickness, PCB copper thickness, PCB surface disposal, color of welding proof ink, color of seal oil black, environmental protection requirements, fire rating, VIA plug hole, aperture tolerance, PCB board bending, PCB forming form and other specifications. Here are a few:
1. Materials: First of all, it is necessary to explain what kind of materials are used to manufacture PCB circuit boards. FR4 is the most widely used.
2. Board layer: Explain the number of layers of PCB boards you make.
3. Welding resistance color: there are several kinds of color can be selected according to the requirements of enterprises, the common color is green.
4. Screen printing color: screen printing font and frame color on the PCB circuit board, generally selected as white color.
5. Copper thickness: generally according to the current of PCB circuit to carry out scientific calculation of copper thickness, generally thicker, the better, but the cost will be higher, so the demand is reasonable and balanced.
6. Whether the hole is covered by welding resistance: over-resistance welding is to insulate the hole, otherwise it is not to insulate the hole.
7. Exterior coating: spray tin, OSP, sunk tin, sunk gold, gilded and so on.
8. Number: The number of PCB manufactured should be explained clearly.
Three, PCB proofing projects pay attention to things
1. Seriously search and retrieve PCB circuit board files to prevent data problems.
2. All aspects of the implementation of the process is approved, and the manufacturer to implement the process layout.
3. Limit the number of production, cherish quality and save costs.
4. Fully communicate with manufacturers to prevent accidents in advance.
Four, PCB proofing form selection
PCB circuit board proofing is divided into three forms: regular Pcb factory, professional sample enterprises and small copy board enterprises.
1. The goal of regular PCB factories to make samples is to have bulk orders, so of course we expect to return orders; Professional proofing enterprises themselves only do sample or small batch, professional and rapid, adapt to one or two small sample manufacturing, you have a large order to him, he can not do.
2. In terms of quality assurance, it must be that regular PCB factories do a better job than sample companies. Professional sample companies charge fees for selling and sending samples with a small hammer, and do not even need to do flying needle tests. Normal PCB factories usually do flying needle test, from the material to the process are meticulous, careful and professional, so the quality is often successful.
3. A small number of board copying enterprises are also engaged in PCB proofing. After submitting processing materials to customers and obtaining clear recognition of the final scheme, they should quickly provide customers with PCB proofing, functional prototype manufacturing and testing, so as to ensure its operability.