With regard to the point of "open window through hole" and "cover oil through hole" (the usage of PAD and VIA), many customers and design engineers often ask what this means when ordering a system, which option should I choose for my files? The following is the explanation of this problem point:
Sometimes the conductive hole is treated with PAD attribute, and sometimes the key hole is treated with VIA attribute. The via attribute and pad attribute design are confused, which leads to wrong processing. This is also one of the problems frequently complained about. And for the circuit board production factory, in the processing of CAM data, some processing film engineers, because the customer design document is not standardized, and the wrong, to help customers modify the document, the design is not standardized, with their own experience to deal with the engineering data, which leads to and contributes to the customer's design is not standardized. Keyou circuit hereby state: The last time you did the right, does not mean your document is right! All engineers must pay attention to the design standards and specifications! Keyou circuit will again strictly require all processing of film engineers, as far as possible to maintain the status of customer documents! As far as possible to do according to the design specification and standard processing, not according to the so-called experience processing! Reflect the problem, so that you can design engineers do a reference, improve the quality of design and reduce the occurrence of problems!
This article focuses on conductive holes, keyholes, and the connection between Protel 99 SE/pads/ and CAM350 geber files Conductive holes: via keyholes: pad is particularly prone to several problems:
First, via in the conversion process, because of the design is not standard or you are not clear on the conversion gerber setting rules, and cause problems when you send the gerber file, the factory can not distinguish those are through the hole and those are insert key holes, the only recognition is according to the file processing, which helps the welding layer that there is a window! The gerber you sent out is the film file, and the factory has no way to check whether it is conductive hole or keyhole. Please check the gerber file to see if it is helpful for welding layer. If it is, open the window, if it is not, cover the oil.
Two, pad and via mixed use, resulting in problems
1. When your files are pads or protel, send them to the factory and ask for the cover oil. Please note that you need to carefully check if your pad is also useful via, otherwise you will get green oil on your PAD hole and it will not be possible to weld the point: The plug-in hole must be sprayed with tin. Why did you cover the oil and how did I use it? Please check the file when saying this, whether it was designed by pad or via!
2. When your files are protel or pads, send the files to the factory, and the order requirement is through hole cover oil. Many customers use pad(plug-in holes) to represent conductive holes, which leads to the opening of your conductive holes. Then please check your document design!
Keyou circuit at this point, again as follows, if you are via, press via, if you are pad, press pad! Because no one will know that yours is a conductive hole, that is a plug-in hole, and via and pad are the only identifiers, please be clear!
Three, how to design hole cover oil in protel or pads! This is the most standard practice, if the design standard, it will not go wrong!
In protel, there is a tenting option in the via property. If you check it, it must be cover oil. Then what you turn out is all cover oil. When you output soldermask (solder layer), just check the soldermask top -- via below, which means all pass through the hole to open the window. If you do not check, pass through the hole cover oil. You have two choices via. If you provide the original file, you can choose when placing the order. If you provide the gerber file, please check whether the gerber file meets your requirements!