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Why Dry After DI?

Dave F

#15150

Why Dry After DI? | 6 July, 1998

Aside from process flows where the next step is: 1 Powering-up an assembly 2 Testing the assembly on electronic test equipment Is there a reason (need) to dry assemblies after water washing followed by a DI water rinse? Or is air drying OK? Dave F

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Steve Gregory

#15156

Re: Why ask why? Bud Dry After DI? My, my, my... | 6 July, 1998

Hey Dave... The only reason I can think of wanting the boards good and dry after the wash is just what you've listed...power-up. I had some boards that went right into ICT right after the cleaner but still had a little water in the right angle connectors (which I haven't found a cleaner yet that will dry those bad boys good...) which of course came up a failure until we could dry them out. They first started having someone sit there with compressed air blowing the damn things out (which I couldn't stand watching them do), so I cranked the heat up in the wash temperature to drive some more heat into the assembly. You'd be suprized how much moisture is actually driven off if it's got some heat in it after the board has been sitting outside of the cleaner for a while.. -Steve Gregory-

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Wayne

#15157

Bud Dry After DI? My, my, my... | 7 July, 1998

| Hey Dave...

I agree with Steve, get them dry. Even though you are using DI water, once exposed to normal atmoshere the DI residue water will become contaminated. Fungus and board failure down the road. Not to mention if you plug it into test and heat things up all kinds of nasty things can happen. Heat will aid in reducing moisture content and extending the drying cycle is a safe starting point. Just my thoughts Wayne

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smd

#15151

Re: Why Dry After DI? | 7 July, 1998

I am about to place a huge PO for ESD boxes. Our assemblies need to be placed horizontally in the stainless racks until wavesoldered, but after the wash they will be placed in the boxes. The boxes have a conductive film but they are still cardboard boxes (Plastic is too expensive). So am I going to be the company putz for all time? I use an Electrovert H-400 Hydroclean. What do you guys suggest? Am I going to be OK? I just got the VP to approve this <20 minutes ago and now I read about this! I know a little water could sometimes get into our 80 pin connectors, but I thought I'd be OK. | Aside from process flows where the next step is: | 1 Powering-up an assembly | 2 Testing the assembly on electronic test equipment | Is there a reason (need) to dry assemblies after water washing followed by a DI water rinse? Or is air drying OK? | Dave F

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Dave F

#15152

Re: Why Dry After DI? | 8 July, 1998

smd: I think the idiom is "schmuck," rather than "putz." ;-) What are you concerned about? That the residual water in the 80 pin connector housing will flow down the boards and rot-out the bottom of your new boxes? Dave F | I am about to place a huge PO for ESD boxes. Our | assemblies need to be placed horizontally in the | stainless racks until wavesoldered, but after the | wash they will be placed in the boxes. The boxes | have a conductive film but they are still cardboard | boxes (Plastic is too expensive). So am I going to | be the company putz for all time? I use an | Electrovert H-400 Hydroclean. What do you guys | suggest? Am I going to be OK? I just got the VP | to approve this <20 minutes ago and now I read | about this! I know a little water could sometimes | get into our 80 pin connectors, but I thought I'd | be OK.

| | Aside from process flows where the next step is: | | 1 Powering-up an assembly | | 2 Testing the assembly on electronic test equipment | | Is there a reason (need) to dry assemblies after water washing followed by a DI water rinse? Or is air drying OK? | | Dave F

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smd

#15153

Re: Why Dry After DI? | 9 July, 1998

OK, I'll take a little abuse as long as you guys are giving me all this great advice. I am concerned about what might happen when a drop here and there comes from the connectors and is absorbed into the box. The box is going to suffer from this. I am going to shell out maybe 3-4K on these boxes (carboard W. burried shielding and some sort of silverish film on the surface) and can't have them getting soggy when filled with 10K worth of boards. What can I do?

| smd: I think the idiom is "schmuck," rather than "putz." ;-) | What are you concerned about? That the residual water in the 80 pin connector housing will flow down the boards and rot-out the bottom of your new boxes? Dave F | | I am about to place a huge PO for ESD boxes. Our | | assemblies need to be placed horizontally in the | | stainless racks until wavesoldered, but after the | | wash they will be placed in the boxes. The boxes | | have a conductive film but they are still cardboard | | boxes (Plastic is too expensive). So am I going to | | be the company putz for all time? I use an | | Electrovert H-400 Hydroclean. What do you guys | | suggest? Am I going to be OK? I just got the VP | | to approve this <20 minutes ago and now I read | | about this! I know a little water could sometimes | | get into our 80 pin connectors, but I thought I'd | | be OK. | | | | Aside from process flows where the next step is: | | | 1 Powering-up an assembly | | | 2 Testing the assembly on electronic test equipment | | | Is there a reason (need) to dry assemblies after water washing followed by a DI water rinse? Or is air drying OK? | | | Dave F

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Steve Gregory

#15154

Re: Why Dry After DI? Or does smd have to pay for the boxes outta his pay check? | 9 July, 1998

Hey there smd... Don't worry, I don't think you'll be the company shmuck, or putz, or doofus, or bone-head, or geek, or ding-bat, or...or...(hmmm, can't think of anything else at the moment)...but you catch my drift, don't ya? I only mean that unless there's something that you've not shared with us that we should know about...(GRIN). Just ribbin' ya'!! I think you'll be okay, those boxes can take quite a bit of abuse...I mean you don't wanna go putting dripping wet assemblies in them, but they can get a little wet and still be okay as long as they dry out in between moisture periods. We used those boxes to deliver finished boards to one of our customers final assembly building where they would test and do the final box assembly of the servers and hubs they built. We would pick-up the empty boxes at their building from the previous days delivery, and once in a while we would have to do that in the rain. The boxes would get a little wet but they would survive... Best thing to do if they get pretty wet though, is to take everything out of them if there is boards in there, and let the box dry before you carry anything else in them...that's when the damage is done, trying to carry something in them if they're wet. -Steve Gregory-

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Wayne

#15155

Re: Why Dry After DI? Or does smd have to pay for the boxes outta his pay check? | 10 July, 1998

| Hey there smd... | Don't worry, I don't think you'll be the company shmuck, or putz, or doofus, or bone-head, or geek, or ding-bat, or...or...(hmmm, can't think of anything else at the moment)...but you catch my drift, don't ya? I only mean that unless there's something that you've not shared with us that we should know about...(GRIN).

Steve /Steve: Take it easy, can't understand why anyone would want to use wet boxes or place boards in a box when they are wet. Lets take care of the customer and provide amle time to dry the boards. 5 P's Prior Planing Prevents Piss Poor Performance.(gues that's the 6 P's) How much moisture could there be on any board that would cause damage to the packing material. I think I would worry that the boards would be damaged more if wet and placed in an esd type wrapping? As for rain in California, you guys know what rain really is. Should be in New England we had 24 days with rain in June... Wayne ps still not use to this new keyboard.

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