Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


reflow profile

steven

#17668

reflow profile | 21 September, 2001

when taking a reflow profile, can i attach the thermalcouple to the component body (using high temp tape) instead of to the leads (often found thermal couple dettached during reflow). in general, what is the temp diff between these 2 locatinos. if solder paste recommanded the peak temp should fall in 210 - 220 degree c, what is the best temp should i see on component body?

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#17669

reflow profile | 21 September, 2001

You can, and for small parts you probably won't see much difference between body temp. and lead temp. For QFPs or PLCCs there will be a much greater delta, though.

I'd be more concerned with the small surface area you're making contact on (spherical thermocouple end on flat component surface). Why don't you bury the thermocouples in the solder joints with high temp. solder? It's a pain with fine pitch, but gives you the best data since it's actually measuring the temperature within the joint (solder).

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#17671

reflow profile | 21 September, 2001

You can measure temperatures any place that you would like, but the issue is the temperature of the solder. We've seen solder temperatures that vary from lead to lead on the same component.

Why don't you want to measure the temperature of your solder?

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dougk

#17677

reflow profile | 21 September, 2001

We're used to placing the theromcouple on the solder joint and securing it with thermally-conductive UV adhesive. It's quick & easy to apply, and I've only seen a couple degrees difference from high-temp solder technique. Thoughts?

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#17678

reflow profile | 22 September, 2001

We like that method for certain jobs. The res sometimes freaks inspectors. We prefer the aluminum tape we've spoken about before on SMTnet.

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#17679

reflow profile | 22 September, 2001

Back-stepping a bit. If a profile is being used to: * Set-up the oven for a new product or trouble-shooting process, the profile should be taken with a solid contact to a solder connection. * Monitoring on-going stable and in-control process that represents the product needs for a good conection, the profile can be taken just about any where, but the thermocouple probably should be in contact with metal.

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Tony

#17680

reflow profile | 22 September, 2001

I like to secure the thermalcouples with a small dot of chip-bonder(surface mount adhesive). The chip-bonder will cure durring the first pass through the oven. After I have developed my profile I remove thermalcouples and the chip-bonder with a soldering iron.. Works great, thermalcouples will not move during profiling.

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bobm

#17713

reflow profile | 26 September, 2001

there is a company called EFD. my contact there is john kaminski. they have thermocouples that are spring loaded requiring no solder at all. they work great. you attach them to the edge of the board and you can move the end to make contact where you want. it is a little investment but they are very nice.

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vance

#17827

reflow profile | 9 October, 2001

does EFD have a website? -vance

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random7

#17831

reflow profile | 9 October, 2001

check out ECD.com for temprobes.

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bobm

#17836

reflow profile | 9 October, 2001

THE PEOPLE THAT MAKE THE PROFILING EQUIPMENT IS. ECD. THERE WEB SITE ADDRESS IS http://www.ecd.com THE CONTACT THERE IS OPAL HILL. PH# 800-323-4548

FAX# 503-659-4422

E-MAIL opal.hill@ecd.com sorry i got companies confused.

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