Why the PCB manufacturer always asked for change in your PCB design?
Few days ago, there has a hardware engineer post two questions :
1) Do you allow your manufacture to do some changes to your PCB Design?
2) if Yes, do you think that the manufacturer can make your design better?
Below is what he have experienced :
I'm working with a Manufacturer for Two weeks to make a really complex board which contains High speed signals , impedance control and BGA components with 0.4 mm pitch. The Manufacture Proposed to do some changes to our layout in order to pass the EQ Tests . I can not allow that as i'm afraid that those changes can affect my board so i did them by myself. what do you think ?
And here are some Answers and commends from the views and most of them are hardware and software engineer .
A: Hello Salem. Each PCB manufacturer has different processes, many use DFM methods tailored to their needs. When a manufacturer asks for specific changes, it is because your design is not optimized enough for manufacturing. It is best to follow your recommendations. What I recommend is that you make the changes yourself, but you must demand that they give you all the possible details so that your design fits your specifications. The process of communication with the manufacturer is key.
B: don't let them do that ,if the board need some rectification ,it's you who will do that especially in impedance controlled board, he can easily brake some clearance or track thickness constraints
C: How to recommend: every time you have a very complex design, check first with the manufacturer before designing the PCB layout. This way you can adapt your DRC to the manufacturer's standards
Exactly especially for complex Designs .
D: 2 weeks? Seems a very long time to still be getting questions from your PCB manufacturer. No wonder they want to finish it for you - you’re making them lose their profit.
E: It should be done in design level but manufacturer often do this, it is better you ask them what changes done then check in design either it will effect or not.
F: Even if they do some changes, you have to check them before proceeding to prod, and do the necessary tests. But taking in account some recommendations from them is a good thing.
What is your idea of above questions?
To answer this two question, let's start with the working process between the designer and the manufacturer
At the very beginning, the designer will send the blueprints and sketches to the manufacturer, and then the manufacturer review all documentation and examine the basic information of the design, materials, copper thickness, circuit space, etc., and they will provide feedback to the engineer to indicate if the board or product is working. All processes are based on the manufacturer's production capacity.
Different PCB manufacturers have different capabilities, so it is important to contact the right manufacturers at the first step.
Once the appropriate supplier is found, the manufacturing process is entered, but the manufacturing process does not occur until the manufacturer converts the format file into a manufacturing document.
During this transaction, PCB manufacturer's engineers will adjust the Gerber format date, for example, the length and width of the wide circuit to avoid open or short circuits, increase copper area to avoid copper deficiency during manufacturing, and therefore engineer design. It is important to leave enough space for the PCB for the manufacturer to adjust the data.
The manufacturer then sends the manufacturing documentation to the engineer for confirmation. The manufacturing process will only begin once confirmed.
As you can see, the PCB manufacturing process is very complicated and any errors can cause PCB damage.
In the above process, an important reminder for the engineer is that the manufacturing data is different from the originally designed data. It is therefore important to understand the capabilities of the supplier. And find the perfect solution for this conflict. It is best to have a team, engineers and manufacturers of engineers can discuss together. In this way, both parties can reach an agreement on the product.