PCB design: distinguishing between "via cover oil" and "via opening window"

Regarding the point of "via cover oil" and "via opening window" (the difference between the usage of VIA and PAD), many customers and design engineers often ask what this means when placing an order on the system, and which option should I choose for my file? The following is an explanation of this issue:

I often encounter such problems. The design is seriously non-standard. It is impossible to distinguish the usage of pad and via. Sometimes the conductive hole is processed with the attribute of pad, and sometimes the key hole is processed with the attribute of via. The design of VIA attribute and PAD attribute is chaotic, resulting in wrong processing. This is also one of the problems that often cause complaints. For circuit board production factories, when processing CAM data, some film processing engineers, because of the non-standard design files of customers, make mistakes and help customers modify the files to make the non-standard design correct. They process the engineering data based on their own experience, which leads to and contributes to the non-standard design of customers. Jieduobang hereby explains: What you did right last time does not mean that your file is correct! All engineers must pay attention to the design standards and specifications! Jieduobang will once again strictly require all film processing engineers to keep the status quo of customer files as much as possible! Try to handle it according to the design specifications and standards as much as possible, and cannot handle it according to the so-called experience! Reflect the problem, so that it can be a reference for all design engineers to improve the design quality and reduce the occurrence of problems!

This article mainly explains the connection between conductive vias, keyholes, and protel/pads/ and geber files. Conductive vias: via keyholes: Several problems that pads are particularly prone to :

1. Mixing pads and vias causes problems

1. When your file is pads or protel and sent to the factory, you are required to cover the vias with oil. You must pay attention to whether your plug-in holes (pads) are also using vias. Otherwise, your plug-in holes will also be covered with green oil, which will cause welding failure. Point of dispute: The plug-in holes must be sprayed with tin. How do you cover the oil? How do I use it? When you say this, please check the file to see if it is designed with pads or vias!

2. When your file is pads or protel, send the file to the factory, and place an order requiring via cover oil. Many customers use pads (plug-in holes) to represent conductive holes, which leads to your conductive holes opening windows. Maybe you want via cover oil. At that time, the point of dispute may be, I want conductive hole cover oil, why is it opened? Then please check your file design!

JDB would like to reiterate this point as follows: if it is a via, treat it as a via; if it is a pad, treat it as a pad! Because no one will know that yours is a conductive hole and that is a plug-in hole, and via and pad are unique identifiers, please be clear!

2. During the conversion process of via, problems may occur due to non-standard design or unclear setting rules for gerber conversion. When you send a gerber file, the factory manufacturer cannot distinguish which are vias and which are key holes. The only way to identify is to process according to the file. If there is a solder layer, there is a window! Point of dispute: I want vias with oil cover, and you have opened a window for me now. I may cause a short circuit. Please check your file. The gerber you issued is a film file. The factory has no way to check whether yours is a conductive hole or a key hole. Please check the gerber file to see if there is a solder layer. If there is, open a window. If not, cover with oil. 3. How to design via cover oil in protel or pads! - This is the most standard practice. If the design is standard, there will be no mistakes!

In protel, there is a tenting option in the via properties. If you check it, it must be covered with oil, so what you transfer out will be all covered with oil. In pads, the pads file needs to be covered with oil through the hole (via). The method is: when outputting the soldermask, that is, the solder mask layer, just check the upper solder mask top —— the via below, which means that all vias are opened. If it is not checked, the via will be covered with oil. In summary: pad is made as pad, this is the plug-in hole, and you have two choices for via. If you provide the original file, you will be asked to choose when placing an order. If you provide the gerber file, be sure to check whether the gerber file meets your requirements!