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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Green coating and through-hole plating

Xingsheng

#14729

Green coating and through-hole plating | 11 August, 1998

Hi, can you please tell me how to make green coating and through-hole plating of PCB? Thanks! Xingsheng

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Dave F

#14730

Re: Green coating and through-hole plating | 13 August, 1998

| Hi, can you please tell me how to make green coating and through-hole plating of PCB? Thanks! | Xingsheng Xingsheng: Welcome. Bible on PCB fabrication: Printed Circuits Handbook, Clyde Coombs, McGraw-Hill Web resources: http://www.pwbrc.org/ and http://www.ipc.org Trade journals: PC Fabrication and Circuitree 1 GREEN COATING is called solder mask. Solder mask resists solder in areas that are not to be interconnected. Keep solder mask away from features that require solder. Solder mask should clear features by 0.004 inches. Solder mask over bare copper (SMOBC). Incorporate SMOBC fabrication technology on SMT boards. Otherwise, solder on the traces under the solder mask will reflow during the SMT soldering process and could bridge between traces. The concern about the potential of bridging between traces increases as the spacing between traces decreases. Solder mask finish. A matte solder mask finish has a higher surface energy than glossy and so, reduces solder ball formation. Types of solder mask. Wet film, dry film, and liquid photo-imageable are types of solder masks. 2 THROUGH-HOLE PLATING. The quick answer is: After drilling; fabricators deburr the holes, desmear the copper plating, and deposition copper on the walls of the drilled holes. After coating, imaging, strip/etch/strip, and solder masking; fabricators coat the copper on solderable areas, including the through holes, with a protectent. The protectent limits oxidation of the copper and preserves its solderability. Solder is the most common protectent. We don�t want to talk about other protectents, because it will just get Earl Moon going. In fact just saying that "solder is the most common protectent" is probably enough to do that. Have fun Dave F

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Earl Moon

#14731

Re: Green coating and through-hole plating | 14 August, 1998

| | Hi, can you please tell me how to make green coating and through-hole plating of PCB? Thanks! | | Xingsheng | Xingsheng: Welcome. | Bible on PCB fabrication: Printed Circuits Handbook, Clyde Coombs, McGraw-Hill | Web resources: http://www.pwbrc.org/ and http://www.ipc.org | Trade journals: PC Fabrication and Circuitree | 1 GREEN COATING is called solder mask. Solder mask resists solder in areas that are not to be interconnected. Keep solder mask away from features that require solder. Solder mask should clear features by 0.004 inches. | Solder mask over bare copper (SMOBC). Incorporate SMOBC fabrication technology on SMT boards. Otherwise, solder on the traces under the solder mask will reflow during the SMT soldering process and could bridge between traces. The concern about the potential of bridging between traces increases as the spacing between traces decreases. | Solder mask finish. A matte solder mask finish has a higher surface energy than glossy and so, reduces solder ball formation. | Types of solder mask. Wet film, dry film, and liquid photo-imageable are types of solder masks. | 2 THROUGH-HOLE PLATING. The quick answer is: After drilling; fabricators deburr the holes, desmear the copper plating, and deposition copper on the walls of the drilled holes. After coating, imaging, strip/etch/strip, and solder masking; fabricators coat the copper on solderable areas, including the through holes, with a protectent. The protectent limits oxidation of the copper and preserves its solderability. Solder is the most common protectent. | We don�t want to talk about other protectents, because it will just get Earl Moon going. In fact just saying that "solder is the most common protectent" is probably enough to do that. | Have fun | Dave F Dave, Just when I was becoming a nice guy again, you go and do this. However, I must say, you sure know a lot about boards - so when do we get an adequate replacement for HASL. Did you notice the posting in the IPC TechNet concerning the latest surface finishes council meeting. Maybe we'll get some good news soon. Moonman

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Dave F

#14732

Re: Green coating and through-hole plating | 14 August, 1998

| | | Hi, can you please tell me how to make green coating and through-hole plating of PCB? Thanks! | | | Xingsheng | | Xingsheng: Welcome. | | Bible on PCB fabrication: Printed Circuits Handbook, Clyde Coombs, McGraw-Hill | | Web resources: http://www.pwbrc.org/ and http://www.ipc.org | | Trade journals: PC Fabrication and Circuitree | | 1 GREEN COATING is called solder mask. Solder mask resists solder in areas that are not to be interconnected. Keep solder mask away from features that require solder. Solder mask should clear features by 0.004 inches. | | Solder mask over bare copper (SMOBC). Incorporate SMOBC fabrication technology on SMT boards. Otherwise, solder on the traces under the solder mask will reflow during the SMT soldering process and could bridge between traces. The concern about the potential of bridging between traces increases as the spacing between traces decreases. | | Solder mask finish. A matte solder mask finish has a higher surface energy than glossy and so, reduces solder ball formation. | | Types of solder mask. Wet film, dry film, and liquid photo-imageable are types of solder masks. | | 2 THROUGH-HOLE PLATING. The quick answer is: After drilling; fabricators deburr the holes, desmear the copper plating, and deposition copper on the walls of the drilled holes. After coating, imaging, strip/etch/strip, and solder masking; fabricators coat the copper on solderable areas, including the through holes, with a protectent. The protectent limits oxidation of the copper and preserves its solderability. Solder is the most common protectent. | | We don�t want to talk about other protectents, because it will just get Earl Moon going. In fact just saying that "solder is the most common protectent" is probably enough to do that. | | Have fun | | Dave F | Dave, | Just when I was becoming a nice guy again, you go and do this. However, I must say, you sure know a lot about boards - so when do we get an adequate replacement for HASL. | Did you notice the posting in the IPC TechNet concerning the latest surface finishes council meeting. Maybe we'll get some good news soon. | Moonman Earl: You're a nice guy who has forgotten more than I'll know. I hope "The Council" takes a stand. Dave F

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