[Help]:Smaller footprint of 0402 SMD capacitors

[smithchart]

Dear All:

I need to create a customized 0402 capacitor footprint(SMD) to use in MentorGraphic Expedition. The recommended size from IPC-SM-782A is too large for me. May I know what is the minimum pad size, pad pitch, solder mask, body outline size etc. that I can use?

Thanks in advance.

Regards,

 

[actra]

0402 means 0.04" X 0.02" which is 1.016 X 0.508 mm

 

[Drew3rdOF3]

Talk to the people who are going to assemble your design. They will tell you what can and cannot be assembled and how much the price may differ with a smaller footprint. Also make sure it can be probed without shorting it to its next door neighbor.

 

[smithchart]

Dear Drew3rdOF3:

Thanks for your reply. I am in the prototype stage for a high-speed application and what I want to know is what could be the-state-of-the-art fabrication and assembly process for the footprint I required before I go to source for the prototype and assembly house. Any idea about this?

Thanks.

 

[Drew3rdOF3]

One of my favorite things to do is take a tour of fabrication and assembly houses as often as I can. You should make every attempt to do this if at all possible. It is very important to get both fab and assy involved in your design as soon as possible - long before completion. Get documentation from as many fab/assy houses as possible. Try to insist on talking with the people that actually do the work.
If you have not already done the above, you will be surprised at the help you get because they want your business. They know that even if you do not go with them for that design for whatever reason, there is a good possibility you will feed them in the future. Directly or indirectly. I might still have contacts in the Southern California area if that will work for you. In all cases, anyone who will not give you the time is a waste of time.
I have acquired some pretty tight footprints and placements by keeping everybody in the loop. However, I will not disclose them because of NDAs in place, and/or I have no wish to burn any bridges.

You already have a great resource with the internet. Websites usually have their capabilities listed in some form or other.

That being said, the technology is always advancing. You may get better results than I have, but I will help with what I can; There is a lot of competition in this world so when I will not give you the answers, I *will* show you where to find them.

 

[alex840]

you can try to use the "least" footprint from the new IPC7351. they are quite small, really.