PCB defects

[dgowey]

I've just received a run of PCB's where about half of them have a defective soldermask. The PCB surface has a green/copper striped appearance with the stripes being about 1/16" wide (like brush marks). Soldermask does appear to cover the whole board, but varies in thickness. Has anyone else encountered this and is it something to worry about or just an appearance defect?

[Tom]

I have one question about the board finish. Was it plated with Immersion White Tin (IWT)?

The reason I ask this is because Hallmark Circuits was having the same problem with a new Immersion White Tin line. They said that it was too harsh on the solder mask because the tin is a hard metal. They had the Immersion White Tin line removed and they replaced it with an Immersion Silver (IAg) line and that has worked out much better.

The Immersion White Tin boards with the scrape marks on the solder mask worked OK but it looked ugly.

[dgowey]

Thanks for responding, Tom.
The plating is HASL (not IWT) with LPI soldermask.
It's nothing new or unusual for us - same board house that we've used for years.
I tend to think this is just a cosmetic defect, but just looking for other opinions.

[Tom]

I think your boards will work fine as long as the brush marks are surface marks and do not pierce the solder mask.

I personally have never seen a board with your description, but it sounds like a cosmetic problem that will not affect functionality.

It's always nice to know who the manufacturer is (you could have mentioned their name) so we can pin down comparative results coming from a specific vendor. Then we could dissect it into machinery problems or human error.

[dgowey]

For those interested, the manufacturer is Circuit Services World Wide in Bellevue, WA.
I should mention that we have used them for years and have rarely had problems with workmanship or delivery.
I am planning to bring this to their attention to figure out what happened and to (hopefully) prevent it from happening again in the future.

[dovo]

Hi friend,
Why don't you try us? We are Megal Circuit, Inc.
We are located at Fountain Valley CA.


MEGAL CIRCUITS, INC.

You may not recognize the company name on the letterhead, but I think it will become familiar quickly--I’ve started my own Printed Circuits board Company.

Megal Circuits, Inc. is the leading manufacturer of technically demanding printed circuit boards; flex circuits, rigid-flex circuits.

As you know, I’ve spent nearly fifteen years as a Printed Circuits Board Engineer. I’m putting that background to use in my new company.
We provide quality electronic manufacturing and printed circuit board designs, whether your application is commercial, industrial, MCI has the experienced staff and equipment needed to design and manufacture your products.
As a Contract Electronic Manufacturer and Printed Circuit Design Service, we provide a complete set of solutions to firms incorporating printed circuit boards into their products. We use industry standard CAD systems and high-end tooling to optimize the assembly process. We can provide material acquisition and Design for Manufacture enhancements. There is no substitute for having skilled designers working in the same facility where the product is manufactured. With these in-house capabilities, we can offer savings on the assembly of new as well as existing products. These resources give our customers a high quality product at a reasonable price.
Our goal is to offer development and production solutions tailored to fit your needs. If you need a vendor with tremendous attention to detail and the patience to do it right the first time, then please contact us.
Thank you for your time.

Sincerely,

Dominique Vo
President

[Lameris]

Personally, if consistantly you don't have a problem, I wouldn't mention your vendor name. One potential issue, that you haven't even fully discussed with them yet, out of lots of good boards doesn't make them a bad supplier.

[Tom]

Gary,

I absolutely agree that one batch of bad boards does not make a manufacturer a bad supplier. But, when you mention the manufacturers name so everyone can see, other people might be experiencing the same exact defect as the one mentioned from the same supplier.

In today's complex web of technology with acquisitions taking place regularly and plant closures happening everywhere it's nice to know what's going on. Statements like "I've been using this manufacturer for 4 years with no problems and all the sudden I got a bad batch of bad boards" That doesn't tell us anything that we can relate to or accurately respond to.

Mentioning a manufacturers name should not be a negative statement, but rather "Is anyone else using this manufacturer having a similar problem?”

Good manufacturers of the past can quickly become bad manufacturers by change of ownership, employees, management or whatever. This process happens rather quickly and we only help ourselves by pointing these issues out in a constructive way (not a negative way). I like to know what's happening out there in the world. We help each other that way.