PCB Technical - PCB copy board software and method for preventing fingerprints

1. How to use PCB company copy board software:

Function: In the case that the original PCB file is missing or damaged, we can use the existing GERBER/ODB++ file to reversely generate the PCB file to make up for the loss!

Function steps: (Take the reverse generation of PCB from the existing GERBER file under the AD9 installation file as an example, the following required files can be generated by the user using the PCB file!)

1. Create a new CAM file in AD9.

2. Import Gerber files exported by other software through File/Import of AD9. Use the example of 4 Port Serial Interface.

It can be found in Program Files\Altium Designer 9\ Examples\Tutorials\CAMtastic Imports &Exports\Gerbers. We select File\Import\QuickLoad on the CAMtastic editor menu, and the following page will pop up, we select the above path. Then click "OK". The CAMtastic editor will automatically load and display the individual CAM data. Then the "Import Drill Date" dialog box will pop up. After we select "OK", a report file with the suffix ".log" will pop up. If there is a file error during the import process, it will be displayed in this file so that we can find it easily.

3. Import NC Drill files and netlist files output by other software through File/Import of AD. (If you are using ODB++ files, you can omit this step)

The NC Drill file is in the Program Files\Altium Designer 9\ Examples\Tutorials\CAMtastic Imports & Exports\ directory, and its name is "4 Port Serial Interface.txt".

The netlist file is in Program Files\AD9\Examples\Tutorials\CAMtastic Imports & Exports\Gerbers\ The import method is the same as that of NC Drill

4. Use Tool/Netlist/Extract to extract the imported Gerber network (the connected tracks are regarded as the same network, and the network name is randomly generated). If you do not import the netlist, you will not be able to rename the network, and the generated PCB file network name will be confused! We can select Tools\Netlist\Extrast to extract the netlist from the CAM data.

If the electrical network table is imported correctly, we can select Tools\Netlist\Rename Nets to change the name of the network.

5. Export the CAM file to PCB via File/Export/Export to PCB. So far, the import function is basically completed, but all the components have been decomposed into Pads, and the Designator on the overlay is no longer Text type.

2. How to prevent PCB (fingerprints)

There is artificial hype in almost every aspect of the PCB manufacturing process. This will cause a problem: the PCB is exposed to bare hands, leaving fingerprints on the board.

"Fingerprints" are a major scourge of PCBs, and one of the main reasons for poor PCB scrapping and end-user reliability degradation. In the PCB processing process, the hand and the board are in frequent contact, so fingerprints have become the most difficult problem in the industry. Let's talk about the causes, hazards and avoidance methods of fingerprints that can cause bad PCB boards:

1. Fingerprints: Fingerprints are sweat stains on the hands. Its main components are as follows:

A, water B, inorganic salts (such as Nacl, etc.) C, fatty oils (non-minerals) D, cosmetics and skin care products E, all kinds of dirt touched by bare hands (or dirty gloves) 2. Fingerprints Hazards in the PCB manufacturing process A. When bare objects touch the board, a chemical reaction occurs in the copper on the board surface in a very short time, resulting in oxidation of the copper surface. After a longer time, it will show obvious fingerprints after electroplating, and the uneven coating will cause serious defects in the appearance of the product.

B. The bare hand touch board before solder mask will cause the solder mask to fall, resulting in poor adhesion of the green oil, and it will blister and fall off during hot air leveling.

C. During the process from the solder mask to the packaging of the gold board, touching the board surface with bare hands will cause the board surface to be unclean and cause poor solderability or poor bonding.

D. Printed wet film or silk-printed circuit and the board surface before lamination has fingerprint grease, which can easily cause the adhesion of the dry/wet film to decrease, and cause the penetration and separation of the plating layer during electroplating, and the gold plate is easy to cause the board surface The pattern will oxidize the surface of the board after the solder mask is completed, and the color of yin and yang will appear.

If the above phenomena are not standardized and eliminated, it will damage the qualified rate of the product and the one-time pass rate, resulting in a long production and processing cycle, a high rework rate, and a low on-time delivery rate, which will damage the company's image in the eyes of customers.

3. How to prevent bare hands from touching the board is the key link to radically eliminate fingerprints. A. Every employee is required to develop a good habit of picking and placing the board. B. Carry gloves and finger cots. C. Be sure to wear gloves in the process of wearing gloves. Gloves (such as cloth gloves, rubber gloves, finger cots, etc.) D. Lead by example, teach by precepts and deeds, set up an image role model, and engrave a jingle in your mind: "Hold the edge of the board flat and lay flat, palm as the axis, coaxial rotation".