Bubble Board

Wow, a tented via you can sleep under!

Cheers

Phil Hobbs

-- Dr Philip C D Hobbs Principal ElectroOptical Innovations

email: hobbs (atsign) electrooptical (period) net

On a sunny day (Tue, 05 Oct 2010 15:21:43 -0700) it happened John Larkin wrote in :

I think this is some reflection, as the lines are still straight.

Chinese? ...or Indian?

John Larkin a écrit :

If you have internal planes that'll make for a one giant key keyboard.

Chinese. Two boards out of 45 did this.

John

John

Mine are much nicer.

Actually, even my homemade PCBs don't suffer from that malady :)

Tim

-- Deep Friar: a very philosophical monk. Website:

"John Larkin" wrote in message news: snipped-for-privacy@4ax.com...

"John Larkin" wrote in message news: snipped-for-privacy@4ax.com...

Be interesting to slice that in half to see what delaminated. My guess is excessive moisture in one of the materials, either the G10 or the prepreg. Did that bubble during IR?

Cheers

You won't do any better from India. Their physics is different over there, too.

We've seen delamination on some Nelco material. It was apparently caused by the higher temperatures needed for lead-free solder. We have switched to FR408HR.

Bob

When I looked at it, it looked like an optical illusion - what I saw was a crater about 1/4" deep at the center, with the traces floating in space over it.

But you say it's more like a blister?

Thanks, Rich

How so? Is it some kind of mystical Hindu thing?

Thanks, Rich

Just... wow.

They shipped them like that? Has anyone mentioned "Q.C." to them?

Mark L. Fergerso

I see that you added parts to this board.

So, does this board work ??

Defects like this show up when a board goes through the reflow oven. It doesn't matter if the board works, it's scrap.

On a sunny day (Tue, 05 Oct 2010 16:42:04 -0700) it happened John Larkin wrote in :

So do they charge extra for that?

On a sunny day (Tue, 5 Oct 2010 19:17:48 -0500) it happened "Tim Williams" wrote in :

WhY dO yoU GuyS oNLy PaINt tHE cOMPonENtS, WhY nOT uSe rEAL ComponENTs?

This particular one? Don't know. We're not going to add the LCD or the connectors. We sure wouldn't sell it if it did work.

It's an LCD display board that emulates a VF display board. Noritake EOLd the VF glass, so we did a little substitute board that uses an Atmel processor to intercept the multiplexed 16-segment VF scan, figure out the original ASCII, and drive an LCD. The board in the pic is fully stuffed with the parts we actually use, except for the VF itself, which is bolted on and hand-soldered after reflow, and the ribbon cable header, also hand soldered.

We used the VF display board in about 7 different products, so it was easier to do this than to booger the code in all of them. Future products would talk directly to an LCD, of course.

John

No, two out of 45 bubbled up as they passed through the reflow oven. Bad lamination, maybe trapped moisture?

A couple of times lately, we bought boards from local PCB houses who seem to be outsourcing to China. But they don't seem to be QCing what comes back. We recently got one lot of boards with horribly mis-registered drill holes, breaking out of the vias, and at least one obvious trace repair (wire jumpers over traces, painted same color as the solder mask) per board. Sent them all back.

John