Professional PCB manufacturing and assembly
Building 6, Zone 3, Yuekang Road,Bao'an District, Shenzhen, China
PCB Design
PCB Design
How to deal with the problem of "overhole cover oil" and "overhole opening window" in PCB processing?
Kim 0 Comments

How to deal with the problem of "overhole cover oil" and "overhole opening window" in PCB processing?

Regarding the point of "through hole opening window" and "through hole cover oil" (the use of PAD and VIA), many customers and PCB design engineers often ask what this means when placing an order, which option should I choose for my file?


The following is the explanation of this problem point:

Sometimes the conductive hole is processed with PAD attribute, and sometimes the plug-in hole is processed with VIA attribute. The design of via attribute and pad attribute is 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.


Chengdu Zicheng Electronic hereby states: What you did right last time does not mean that your document is right! All engineers must pay attention to the design standards and specifications! Chengdu Zicheng Electronics will again strictly require all the 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 give the PCB design engineers to do a reference, improve the design quality and reduce the occurrence of problems!


This article mainly explains conductive holes, plug-in holes, and the connection between protel /pads/ and geber files. Conductive holes: via, plug-in holes: pad especially prone to several problems:

One, 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 those are plug-in holes, the only can identify 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 plug-in hole. Please check the gerber file to see if it is helpful for welding layer. If yes, open the window, if no, 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 whether your pad (pad) is also used for via, otherwise green oil will be on your pad and it will not be able to be welded.

Contention: The plug-in hole must be sprayed with tin. How did you cover the oil and how did I use it? Please check the document when saying this. Is it designed by pad or via?


2. When your files are protel or pads, send the files to the PCB 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!

Chengdu Subroutine electronic to this point, again as follows, if you are via, press via, if you are pad, press pad! Because no one will know which conductive hole you are, which 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 exporting 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.


To sum up: pad according to pad, this is the plug-in hole, via you have two choices, 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!

Just upload Gerber files, BOM files and design files, and the KINGFORD team will provide a complete quotation within 24h.