Are our design contractors trying to get us closed down?

Hello,

We have gotten some LED lamps designed and prototyped for us by external design contractors.

The Lamps comprise four LED PCB's , each dissipating ~1.8W.

These PCBs have been glued to a solid vertical aluminium bar, -the glue used is Loctite 382........

Loctite 382 datasheet:
http://tds.loctite.com/tds5/docs/382-EN.PDF


This glue has very poor thermal conductivity and is extremely expensive ($18.51 for ONE SINGLE (!!) 20gram bottle based on 200 bottles quantity)

20 gram bottle of loctite 382:-
http://www.loctite.co.uk/cps/rde/xc...redDotUID=productfinder&redDotUID=1000000IE5R

...not only this, but it has a glass transistion temperature of 120degC, and we're thinking the LED PCBs could get that hot and melt the glue.


We are worried that the design contractor is in cahoots with our competitor, and that this poor choice of glue just compounds our belief.


Do you think they are trying to ruin us by specifying this poor-choice glue?




(it does have the advantage of being fast-setting, but then again, that also means the production staff will have to keep screwing the lid on and off)

grizedale said:

Hello,

Do you think they are trying to ruin us by specifying this poor-choice glue?

Click to expand...

If you're the designer you should in some way be defining the glue. Either by specifying it directly, or by giving them performance requirements. Did you tell them the expected operating temperature? Did you give them a requirement for thermal conductivity? Did you give them a cost goal?

Even if the sabotage you describe is for real, it will take at least a few concerned parties to persuade a higher-up to look into it.

Whatever boss went with the decision to use the wrong glue, he's unlikely to want to change.

That's assuming you are able to locate the one who can make any kind of decision.

He might take action if you can show him that a few units failed in service.

I guess you will consider someone with more design experience next time, If you had specifications and they were not met, then they did not complete the task.. If there were paper napkin specs ,m then your company did not complete the task. Either way, I am not surprised by the lack of experience.