Topic: New Official AMT Thread - page 42. (Read 149482 times)

No argument there. BM.ch seems to have recovered from those mistakes much better.

No argument there on the scrap factor. Thermal bumps are not final assembly. They are either on the board at time of production or not. And yes  continuing to bolt on sinks and burn, er, run the boards when they have such an easily seen by eyeball & felt by finger defect certainly not very smart.

But when mechanicals/thermals are not assembled properly and you just keep putting power on unit after unit that was delivered working, you end up with a huge scrap pile. 

aside from many/most of the backside thermal contact pads having anywhere from 25 to 50% of the thermal contact bumps not being there... Make nice jacks for pushing the board away from the sink.

The big silver dots are smushed (as they should be) thermal bumps. Most are not present at all. Folks who still have miners unreturned can easily unbolt the heatsinks and verify this. If the bumps were such a problem to make properly then even a thin copper foil shim would have done the trick.

Just tossing this out there for general information:
http://www.edn.com/electronics-blogs/the-workbench/4421218/PCB-layout-tips-for-thermal-vias

http://circuitcalculator.com/wordpress/2006/03/12/pcb-via-calculator/

http://m.eet.com/media/1200036/XLamp_PCB_Thermal.pdf

Those are examples of standard industry practice reference items for thermal via design. Even if not explicitly specified in 'build-to-print' any CM should:
a. Knowing the thermal needs for the A1 assumed maximum thermal transfer is needed meaning; heavy-plated thermal vias at a minimum preferably filled as well, and a full complement of thermal contact bumps on the bottom of the board that are high enough to go past the gap created by green screen layer to make firm mechanical contact with the main heat sink. btw, that layer creates a 3mil air gap. If there are a few bumps but not a full complement - that gap just got increased to 8-10mil. Thermal compound is not going to make up for that...

b. Flagged the above concerns and asked their customer to verify what is needed to meet industry-standard practice for working with high-power packages. If the customer is unsure then follow Best Practice and overkill the issue.

Then there is the matter of basic Ohms law... If the value of 1 component in a divider network is changed while leaving all others the same - the result (output) from that network is vastly different. To keep the network balanced all components need to be scaled by the same percentage.. Even if a customer signs off on the ECN I still would have insisted on a signed declaration spelling out the result of said change just to CMA.

I will leave it up to the Peanut Gallery to figure how this applies to us here I will say that a power chip missing over 50% of its expected cooling path combined with getting hit (very briefly) with excessive core voltage is not long for this world... These are all items that any CM with a design team should have found in initial design review and later design change reviews and known how to address properly.

All this of course in no way gets AMT off the hook for this mess. No matter what they are the ones that have to deal with it. It is just a glimpse into what the production problems were. Their horrible lack of communication skills is a whole 'nother matter and well worth the tomes that have been written here.

AMT did you get my email about my address update so it doesn't go to the wrong house when you ship?

Yes we're sure we have the right court, and this is not a common plea.

AMT

You have said that they owe you over $200,000 and yet the bucks county court of common pleas only has jurisdiction up to $12K. Are you sure you are in the right court?

Why is it a big deal if they were operating from a lodge? I don't don't care if the chips are arranged in a compass and square arrangement as long has it hases and does so safely.

Actually that is the truth. And no, the fact that there is a lodge around the corner didn't really factor into the decision of taking that office. It was vacant, affordable, a shorter commute and cheaper than the last location by $260 a month. Oh, and it wasn't right next to the lawyers that were suing us. There's a Dunkin donuts on the corner guys, maybe we're in cahoots with those guys as well right. And we'll be pre-selling munchkins and the latest Koolata's soon enough.

"Look AMT's office is right next to a Catholic church!  And a park! and if you zoom in on google maps you can see a car parked out front! OH MY GOD" 

Maybe they were in a hurry and didn't walk around it to see the front  LOL

Hold on now, if AMT is performing some masonic ritual over the miners to make them more profitable than I say let them go for it.

You guys are ridiculous.

Yes! Google it and see for yourselves. Don't take my word for it.

No way! AMT's office is in the back of the Masonic Lodge???

Hi AMT. I'll send you another email with my updated address because I have moved about a month ago. Please confirm you get it. Thank you so much for keeping us up to date.

Sounds like more of a "watch out" rather than a "threat".  If I were AMT, I guess I would be concerned that the people that they took money from might just come looking for them and do them harm.  Just saying...

I truly hope no one is physically hurt over all of this.  On the other hand, when you take large amounts of people's money and don't deliver something, I can totally understand the frustration and that they might just physically hurt you.  Again, I don't condone this, but the possibility is high in this situation. 

Yeah clenell!  Thanks for ruining it for everybody.   

Seriously, that may have been the funniest post I have ever read!