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Heat guns and component damage

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#39397

Heat guns and component damage | 31 January, 2006

Does anyone have any information regarding damaged caused to components due to overheating primarily with a heatgun? I'm having a hard time getting engineering to comply. Thanks

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#39398

Heat guns and component damage | 31 January, 2006

Does anyone have any information regarding damaged caused to components due to overheating primarily with a heatgun? I'm having a hard time getting engineering to comply. Thanks

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#39399

Heat guns and component damage | 31 January, 2006

We are currently experiencing problems with delamination during rework/2nd op activity on lead free. I am suspecting this is a result of the use of a heat gun to rework components. My assumption is that the high heat and time in area greatly increase the likelihood of damage.

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#39401

Heat guns and component damage | 31 January, 2006

Ah, yes. The age-old battle of Production Supervision versus Process Engineering.

I guess you just need to tell your Process Engineer, "Pretty please with sugar on top, investigate this f*cking issue."

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Chunks

#39403

Heat guns and component damage | 31 January, 2006

There is none, since we don't know your part or temp being used. A heat gun CAN be used to remove parts with no damage, if its controled. You need to look up your part on the manufacturers web site, find the process data (time/temp)the part is designed for, run an experiment showing the heat gun is exceeding the manufacturers specification.

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#39404

Heat guns and component damage | 31 January, 2006

You see? Chunks, here has the right idea! To the original poster, you need to show this post to your "Desk Jockey" Process Engineer. That's the problem with some Engineers today. They forget everything they learned in Engineering school, they get enamored with the buzz-word speakin' manager with nice hair and glasses, and then they become stupid, and become more manegerial than Engineering...

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RDR

#39405

Heat guns and component damage | 31 January, 2006

Heat guns used improperly will definitely damage components. You must have a controlled heat gun that can be set to the max temp you want pb =215C max, Pbfree maybe 240C max. This heat gun must not be able to be adjusted or you must have total trust in your operators to not change the setting. It also is greatly dependant upon distance from nozzle to part.

We set our guns so the max temp we want is checked right out of the nozzle. This will enable the operator to get real close if they want without overheating the part. Of course this can be messed up as well by starting the operation with the gun right next to the part. We start at 4" away for 1 min. then bring it closer to reflow the part.

Most people don't understand ramp rates, heat absorption etc... A hot air rework should take at least 1.5 min. to remove the part. Most people get in a hurry and don't even come close to the time required.

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#39406

Heat guns and component damage | 31 January, 2006

Comp is relay. I've pulled the spec. Max 240. Using Leister h/g with manual temp settings from 1-6 (20 - 600C)set by the operator. Gun was set to setting 4.

They are using the heat gun to reflow the solder after SMT but before wave.

High failure rate at test. Still can't get engineering to admit issues are related to heat gun usage.

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RDR

#39408

Heat guns and component damage | 31 January, 2006

Relays huh? I can tell you from previous experience that relays are not a good heat gun candidate. Did you check how long this part can withstand the 240? I do not know what the 4 setting is on a liester but it is probably well in excess of the 240C.

What solder are you reflowing prior to wave? Is this a SMT / P.T.H. component? Or just an SMT part?

I have also killed many a relay (more so than even the heat gun) on the wave solder machine. We needed to drop pot temp to 240C (solder temp was at 235C at the board interface level) from 260C and ensure that the dwell time was <3 sec.

I would take a serious look at the wave process also.

I am a process engineer so I don't know if my comments are valid.

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Chunks

#39427

Heat guns and component damage | 1 February, 2006

OK, this is easy. You say HIGH fall out, so I can assume 25 or 50%? If so, run 10 without the heat gun and 10 with. This should show you if the heat gun process is the cause or not. If the relay is a surface mount, hand solder them on. If it's a thru hole relay, use some adhesive such as peelable solder mask or Kapton tape to hole them on.

If you do still have fallout, it may be your wave. I'd double check it before kicking the chairs out from under those dam desk sucking Process Engineers that are only good for making pretty charts and graphs. Try not to get involved in the "blame game", presnt factual data and let the numbers speak for themselves. If anyone still argues with you, they just don't understand what you're talking about.

P.S. I manage our Process Eng. Dept, so my views and statements are from 20 years real life engineering and experiences, plus some mistakes. I still have dried solder paste on my shoe from 3 years ago and scars from wave solder burns. I still get a kick out of people who ask "What's that shiny stuff is?" in our waves.

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slaine

#39428

Heat guns and component damage | 1 February, 2006

RS sell a heat cun that is fully temperature adjustable buy one of them and pre set it to the right temp then put a calibration sticker over the control.

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KEN

#39466

Heat guns and component damage | 1 February, 2006

Many relays use soldered post coil terminatins inside the relay. In one case many years ago I found the SMT relay manufacturer used eutectic solder inside their hermetic relay. The SMT relay would fail because the solder balled up on the post, would fall off (inverted reflow) and short the contacts.

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