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SMT electronics assembly manufacturing forum.


Bill Haynes

#9155

Losing parts in wave | 5 October, 1999

I hope that someone can help me with my problem! I am experiencing a lot of glued on parts falling off in the wave solder machine. A little information about my process: 1)We use Loctite 3609 glue that is used up long before its shelf life 2)Our parts hold up to 1.6Kg of force(our standard) 3)We use a MVIIF for parts placement 4)We use a Panasonic HDP-G1 glue machine for glue placement and 5)Our oven profile is within specs. for our company. I just don't know what to do and would appreciate any help. If more info. is needed, please ask.

Thanks in advance, Bill

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K

#9156

Re: Losing parts in wave | 5 October, 1999

| I hope that someone can help me with my problem! I am experiencing a lot of glued on parts falling off in the wave solder machine. A little information about my process: 1)We use Loctite 3609 glue that is used up long before its shelf life 2)Our parts hold up to 1.6Kg of force(our standard) 3)We use a MVIIF for parts placement 4)We use a Panasonic HDP-G1 glue machine for glue placement and 5)Our oven profile is within specs. for our company. I just don't know what to do and would appreciate any help. If more info. is needed, please ask. | | Thanks in advance, | Bill | Bill: Sorry, but I have to ask.......

Are you absolutely sure that you are losing the parts in the wave?

What objective evidence do you have to support that conclusion?

Is it possible that the parts are being knocked off by less than optimal handling in moving the PCB assemblies from one area to another throughout the process?

Have you walked through your whole process and visually identified where the missing parts are ending up? Good places to look would be at the Screen printing process for your topside assembly, or on support tooling in the pick and place process for the topside parts, or any other place in the process after the adhesive cure?

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Mark

#9157

Re: Losing parts in wave | 6 October, 1999

| | I hope that someone can help me with my problem! I am experiencing a lot of glued on parts falling off in the wave solder machine. A little information about my process: 1)We use Loctite 3609 glue that is used up long before its shelf life 2)Our parts hold up to 1.6Kg of force(our standard) 3)We use a MVIIF for parts placement 4)We use a Panasonic HDP-G1 glue machine for glue placement and 5)Our oven profile is within specs. for our company. I just don't know what to do and would appreciate any help. If more info. is needed, please ask. | | | | Thanks in advance, | | Bill | | | Bill: | Sorry, but I have to ask....... | | Are you absolutely sure that you are losing the parts in the wave? | | What objective evidence do you have to support that conclusion? | | Is it possible that the parts are being knocked off by less than optimal handling in moving the PCB assemblies from one area to another throughout the process? | | | Have you walked through your whole process and visually identified where the missing parts are ending up? Good places to look would be at the Screen printing process for your topside assembly, or on support tooling in the pick and place process for the topside parts, or any other place in the process after the adhesive cure? | | | | Bill, I went through this about 3 years ago and Morris is absolutely correct. The primary cause of glued parts "falling" off PCB's was "less than optimal" (nice choice of words) handling throughout the rest of the process. We were assembling PCB's with press-fit connectors and test-points that had to be inserted prior to thru-hole stuffing and found the press operators were knocking 30 to 50 parts off each assembly. We made them a fixture and all was well.

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Brian Conner

#9158

Re: Losing parts in wave | 6 October, 1999

| | I hope that someone can help me with my problem! I am experiencing a lot of glued on parts falling off in the wave solder machine. A little information about my process: 1)We use Loctite 3609 glue that is used up long before its shelf life 2)Our parts hold up to 1.6Kg of force(our standard) 3)We use a MVIIF for parts placement 4)We use a Panasonic HDP-G1 glue machine for glue placement and 5)Our oven profile is within specs. for our company. I just don't know what to do and would appreciate any help. If more info. is needed, please ask. | | | | Thanks in advance, | | Bill | | | Bill: | Sorry, but I have to ask....... | | Are you absolutely sure that you are losing the parts in the wave? | | What objective evidence do you have to support that conclusion? | | Is it possible that the parts are being knocked off by less than optimal handling in moving the PCB assemblies from one area to another throughout the process? | | | Have you walked through your whole process and visually identified where the missing parts are ending up? Good places to look would be at the Screen printing process for your topside assembly, or on support tooling in the pick and place process for the topside parts, or any other place in the process after the adhesive cure? | | | | Bill,

Several questions:

1) What size of components are falling off - 1206's or Capacitors?

2) Where on the board are the components falling off - edge, middle, leading or trailing edge?

3) How large are the boards that this happening to?

4) Is this happening to a wide variety of boards or just a certain "group" of boards?

I think that we can narrow down the problem if these questions are answered!!!

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Bill Haynes

#9159

Re: Losing parts in wave | 6 October, 1999

| | I hope that someone can help me with my problem! I am experiencing a lot of glued on parts falling off in the wave solder machine. A little information about my process: 1)We use Loctite 3609 glue that is used up long before its shelf life 2)Our parts hold up to 1.6Kg of force(our standard) 3)We use a MVIIF for parts placement 4)We use a Panasonic HDP-G1 glue machine for glue placement and 5)Our oven profile is within specs. for our company. I just don't know what to do and would appreciate any help. If more info. is needed, please ask. | |

Hopefully some answers for everyone! -The objective evidence is the parts floating in the wave bath. -All PCB's are 100% inspected prior to moving to the next process and are stored in stockers during transportation and while awaiting the next process. -The glue side of the board is the last process the boards go through prior to 100% inspection and the parts are on the board then. -The component size varies form 2125's to 3015's and also includes some 22 pin SOIC's. -The parts fall off anywhere on the board without a pattern. -The PCB's range in size from 158mm X 230mm to 330mm X 200mm. -The problem exist on a wide variety of boards. | | Thanks in advance, | | Bill | | | Bill: | Sorry, but I have to ask....... | | Are you absolutely sure that you are losing the parts in the wave? | | What objective evidence do you have to support that conclusion? | | Is it possible that the parts are being knocked off by less than optimal handling in moving the PCB assemblies from one area to another throughout the process? | | | Have you walked through your whole process and visually identified where the missing parts are ending up? Good places to look would be at the Screen printing process for your topside assembly, or on support tooling in the pick and place process for the topside parts, or any other place in the process after the adhesive cure? | | | |

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#9160

Re: Losing parts in wave | 6 October, 1999

| | | I hope that someone can help me with my problem! I am experiencing a lot of glued on parts falling off in the wave solder machine. A little information about my process: 1)We use Loctite 3609 glue that is used up long before its shelf life 2)Our parts hold up to 1.6Kg of force(our standard) 3)We use a MVIIF for parts placement 4)We use a Panasonic HDP-G1 glue machine for glue placement and 5)Our oven profile is within specs. for our company. I just don't know what to do and would appreciate any help. If more info. is needed, please ask. | | | | | Hopefully some answers for everyone! | -The objective evidence is the parts floating in the wave bath. | -All PCB's are 100% inspected prior to moving to the next process and are stored in stockers during transportation and while awaiting the next process. | -The glue side of the board is the last process the boards go through prior to 100% inspection and the parts are on the board then. | -The component size varies form 2125's to 3015's and also includes some 22 pin SOIC's. | -The parts fall off anywhere on the board without a pattern. | -The PCB's range in size from 158mm X 230mm to 330mm X 200mm. | -The problem exist on a wide variety of boards. | | | Thanks in advance, | | | Bill Sounds like only the big ones are falling off and the birdseed is still sticking. How about the gluepatterns, might be not enough dots for the mass? What about dot hight versus standoff ?

Just another 2 questions

Wolfgang

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Mike Cooper

#9161

Re: Losing parts in wave | 6 October, 1999

We have same equipment and used the same adhesive. Switched to Loctite 3618 and problem went away. Check cure profile again. 150C at 90s best. Also, check dot size/patterns. Double dots for chips and 4-dot for SOTs works well for us. Regards.

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#9162

Re: Losing parts in wave | 7 October, 1999

| | | | I hope that someone can help me with my problem! I am experiencing a lot of glued on parts falling off in the wave solder machine. A little information about my process: 1)We use Loctite 3609 glue that is used up long before its shelf life 2)Our parts hold up to 1.6Kg of force(our standard) 3)We use a MVIIF for parts placement 4)We use a Panasonic HDP-G1 glue machine for glue placement and 5)Our oven profile is within specs. for our company. I just don't know what to do and would appreciate any help. If more info. is needed, please ask. | | | | | | | | Hopefully some answers for everyone! | | -The objective evidence is the parts floating in the wave bath. | | -All PCB's are 100% inspected prior to moving to the next process and are stored in stockers during transportation and while awaiting the next process. | | -The glue side of the board is the last process the boards go through prior to 100% inspection and the parts are on the board then. | | -The component size varies form 2125's to 3015's and also includes some 22 pin SOIC's. | | -The parts fall off anywhere on the board without a pattern. | | -The PCB's range in size from 158mm X 230mm to 330mm X 200mm. | | -The problem exist on a wide variety of boards. | | | | Thanks in advance, | | | | Bill | Sounds like only the big ones are falling off and the birdseed is still sticking. | How about the gluepatterns, might be not enough dots for the mass? What about dot hight versus standoff ? | | Just another 2 questions | | Wolfgang | You might also check the clearance between lowest part and edge of solder wave nozzle.

Wolfgang

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ed & tuna

#9163

Re: Losing parts in wave | 11 October, 1999

We also had that issue and feel, as Mr wolfgang feels, That handling or packaging may be an issue. The adhesive bond may be partially fractured and releasing in the wavesolder.

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