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Solder Mask IPC Standard

Dreamsniper

#9090

Solder Mask IPC Standard | 7 October, 1999

Is there an IPC Standard stating the max. number of times that a PCB can pass through a reflow or wavesolder machine without having solder mask breakdown.

PCB is FR4 Solder Mask is LPI Reflow and W/S Profile = Standard

thanks and regards,

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#9091

Re: Solder Mask IPC Standard | 8 October, 1999

| Is there an IPC Standard stating the max. number of times that a PCB can pass through a reflow or wavesolder machine without having solder mask breakdown. | | PCB is FR4 | Solder Mask is LPI | Reflow and W/S Profile = Standard | | thanks and regards, | | Try: IPC-SM-840B and Bellcore TR-NWT-00078

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#9092

Re: Solder Mask IPC Standard | 8 October, 1999

| | Is there an IPC Standard stating the max. number of times that a PCB can pass through a reflow or wavesolder machine without having solder mask breakdown. | | | | PCB is FR4 | | Solder Mask is LPI | | Reflow and W/S Profile = Standard | | | | thanks and regards, | | | | | Try: IPC-SM-840B and Bellcore TR-NWT-00078 | Let me be clear. IPC-SM-840B and Bellcore TR-NWT-00078 define solder mask characteristics. I doubt that they call-out anything about the ablity to bear-up under a quantity of heat cycles.

That you are asking this question makes me wonder, is this someone:

(1) Who is abusing printed circuit boards? ... OR (2) Is unfortunate enough to be trying to assemble poorly fabricated boards?

So Dreambuddy, which are you?

My2�

Dave F

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JohnW

#9093

Re: Solder Mask IPC Standard | 10 October, 1999

| | | Is there an IPC Standard stating the max. number of times that a PCB can pass through a reflow or wavesolder machine without having solder mask breakdown. | | | | | | PCB is FR4 | | | Solder Mask is LPI | | | Reflow and W/S Profile = Standard | | | | | | thanks and regards, | | | | | | | | Try: IPC-SM-840B and Bellcore TR-NWT-00078 | | | Let me be clear. IPC-SM-840B and Bellcore TR-NWT-00078 | define solder mask characteristics. I doubt that they call-out anything about the ablity to bear-up under a quantity of heat cycles. | | That you are asking this question makes me wonder, is this someone: | | (1) Who is abusing printed circuit boards? ... OR | (2) Is unfortunate enough to be trying to assemble poorly fabricated boards? | | So Dreambuddy, which are you? | | My2� | | Dave F | Well I've been hiding for a while so I thought I'd pop in and see what was happening ( some kind peron decided to shorten my car for me, man the longerst 3 week's of my life has been living in a kneck brace! anyway's I'm here and I'm rambling..) So how many time's will the mask go over the wave or through the reflow, I like Dave's question ...WHY ? I theory as long as you don't go over the Tg of the resist you shouldn't start into the plastic deformation or the breaking down of the chain's of the mask, The IPC and Bell Core spec's that Dave mentioned are really the gospel's on the mask's but they won't tell you what your asking. The best folk's to talk to are the mask manufacturer's or the PCB fab house. The problem though isn't so much the mask, I would question your joint's and the life of the part's after a few attmept's at the process. Remember every time you 'cook' a board through the reflow or wave your giving the intermetallic's more room to grow and that's not going to do the PCB much good.

JohnW

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Dreamsniper

#9094

Re: Solder Mask IPC Standard | 10 October, 1999

| | | | Is there an IPC Standard stating the max. number of times that a PCB can pass through a reflow or wavesolder machine without having solder mask breakdown. | | | | | | | | PCB is FR4 | | | | Solder Mask is LPI | | | | Reflow and W/S Profile = Standard | | | | | | | | thanks and regards, | | | | | | | | | | | Try: IPC-SM-840B and Bellcore TR-NWT-00078 | | | | | Let me be clear. IPC-SM-840B and Bellcore TR-NWT-00078 | | define solder mask characteristics. I doubt that they call-out anything about the ablity to bear-up under a quantity of heat cycles. | | | | That you are asking this question makes me wonder, is this someone: | | | | (1) Who is abusing printed circuit boards? ... OR | | (2) Is unfortunate enough to be trying to assemble poorly fabricated boards? | | | | So Dreambuddy, which are you? | | | | My2� | | | | Dave F | | | Well I've been hiding for a while so I thought I'd pop in and see what was happening ( some kind peron decided to shorten my car for me, man the longerst 3 week's of my life has been living in a kneck brace! anyway's I'm here and I'm rambling..) | So how many time's will the mask go over the wave or through the reflow, I like Dave's question ...WHY ? | I theory as long as you don't go over the Tg of the resist you shouldn't start into the plastic deformation or the breaking down of the chain's of the mask, The IPC and Bell Core spec's that Dave mentioned are really the gospel's on the mask's but they won't tell you what your asking. | The best folk's to talk to are the mask manufacturer's or the PCB fab house. | The problem though isn't so much the mask, I would question your joint's and the life of the part's after a few attmept's at the process. Remember every time you 'cook' a board through the reflow or wave your giving the intermetallic's more room to grow and that's not going to do the PCB much good. | | JohnW | | Well one thing is that we have mixed tech bds., smt and through hole, it passes the reflow but after wave soldering the masks blister... I tried to run a bare bd. in our reflow oven twice and it blistered... Another thing, a plain through-hole pcb also blistered after wave-soldering..had checked our wave thermal profile and found to be good, also same with the reflow. This damn blistered pcb's all came from one manufacturer. The rests of our pcb's from other manufacturers run fine. Only this !

thanks and regards,

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JohnW

#9095

Re: Solder Mask IPC Standard | 14 October, 1999

Dream,

Sound's to me like your PCB supplier has process problems, probably outgassing or such from trapped moisture / contaminant's. I thoink it's time you called in your vendor for a chat.

JohnW

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