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Re: PCB through hole activation for copper plating
开云体育I'll agree.? Other than what's mentioned, I've done two layer
boards at home.? Problems are: 1) you can't do vias under chips unless the chips are DIL. 2) the vias have to be fairly large for you to be able to solder to them. 3) lacing wire through 200 holes is a pain. 4) No way to do 4 layer boards, or even 3 layer boards.? Yes, you can, but you're going to have to drill a pit in the top layer and run a wire jumper to a pad. 5) most automatic routers assume you're going to a commercial PCB manufacturer, and route the board accordingly.? You're likely to need to manually route the boards.? (Vias underneath chips (fixable), close pad spacing, etc.? You can do it, likely enough, but will the design autoroute?) We won't talk about the problem in getting the top and bottom layers registered, however you decide to do it. My immediate response is that past a certain level of complexity, making your own boards needs stuff you don't have, and is a significant investment (chemical baths to plate through holes, upside down drills to accurately drill holes (did that one....), and the like.? Even the tin-lead plating involves chemicals that seem to be nasty. all of this VERY much depends on the level of complexity of your board.? Me?? I've moved to Chinese made boards with 6 mil traces, TQFP-144 chips and plated through holes.? I don't know how to make them myself. Harvey
On 6/13/2020 4:48 PM, Lee Studley
wrote:
>From a pro, |
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Re: PCB through hole activation for copper plating
From a pro,
If its only 2 layers and you insist on real through hole, it's most time and cost effective to just have them made at an online boardhouse( dirt cheap). Otherwise the threading a long length of fine wire and soldering if wave soldered, then snipping, or if smt, as a post-task is the way to go. If more than 2 layers, get them made. ? |
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Re: PCB through hole activation for copper plating
开云体育Just a comment about eyelets, not at all suggesting to use them: Many, many decades ago I worked at Motorola when eyelets were used. The original style, and common today, is a tube with the top edge rolled over.? There was no problem wave-soldering the bottom or the component wire if present.? The problem was that the solder inside the eyelet would not consistently flow over the top edge? of the eyelet onto the top PCB pad.? In effect only an unreliable mechanical contact was formed on the top side. ? The problem was resolved by using eyelets with a slit in them that allowed the solder to flow out onto the top pad. Actually there was no rolled over edge, the eyelets were straight slit tube sections that were expanded on top and bottom as part of the eyelet insertion process. Bertho ? ? From: [email protected] <[email protected]> On Behalf Of Terry Gray
Sent: Friday, June 12, 2020 19:46 To: [email protected] Subject: Re: [homebrewpcbs] PCB through hole activation for copper plating ? And again, not looking for a mechanical solution.? Already tried eyelets...they suck for so many reasons, the foremost being inconsistency of connection. Already tried soldered wires...this also sucks...mainly being a PITA to solder and they only address vias.? Any through hole connectors can't be done this way. |
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Re: PCB through hole activation for copper plating
Jim Higgins
Received from Terry Gray at 6/13/2020 00:17 UTC:
Jim, Sodium Hypophosphite Monohydrate is apparently a controlled substance but for whatever reason it seems to be much easier and far cheaper to obtain than its cousin Calcium Hypophosphite, and I haven't talked to anyone that knows why! I can obtain it from several places in the US as well as from several Chinese vendors on Alibaba for a much lower price than CH. Perhaps I'm wrong, but I bet you found places that list a price for it, and seem to indicate it's available, but the real hassle will come when you actually try to order it. Established labs/companies with a good reason can get it in limited quantities, but as a home hobbiest (assuming here) it's another story. I truly wish you luck. Jim H |
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Re: PCB through hole activation for copper plating
I think that are difficult to understand all the content of the site, but I want put focus in this process that doesn't use calcium hypophosphite:
On Friday, June 12, 2020, 5:53:15 PM GMT-3, Terry Gray <twgray2007@...> wrote:
Thanks everyone for your replies and sugestions. Thanks, Matheus!? While not exactly what I was hoping for, this is a reasonable solution.? I will give a shot at trying to "make" calcium hypophosphite.? Been a looong time since I dabbled in chemistry but maybe it is like riding a bicycle and you never forget how! And, for anyone who cares, calcium hypophosphite is available from several vendors on alibaba.? They all advertise the stuff for pennies per gram but when you request a quote all of them come back in the neighborhood of $100 per 500G.? Then when you tell them you are in the US, the price jumps up to about $500 per 500G.? This is well beyond the range of most hobbyists...at least well beyond mine.? Now I am off to price diy calcium hypophosphite! Thanks again! |
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Re: PCB through hole activation for copper plating
Jim, Sodium Hypophosphite Monohydrate is apparently a controlled substance but for whatever reason it seems to be much easier and far cheaper to obtain than its cousin Calcium Hypophosphite, and I haven't talked to anyone that knows why!? I can obtain it from several places in the US as well as from several Chinese vendors on Alibaba for a much lower price than CH.
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Re: PCB through hole activation for copper plating
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-------- Original message -------- From: Terry Gray <twgray2007@...> Date: 6/12/20 6:45 PM (GMT-06:00) Subject: Re: [homebrewpcbs] PCB through hole activation for copper plating Also have tried conductive inks, paints, resins.? Never got more than about 75% of the holes being conductive. |
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Re: PCB through hole activation for copper plating
And again, not looking for a mechanical solution.? Already tried eyelets...they suck for so many reasons, the foremost being inconsistency of connection. Already tried soldered wires...this also sucks...mainly being a PITA to solder and they only address vias.? Any through hole connectors can't be done this way.
Also have tried conductive inks, paints, resins.? Never got more than about 75% of the holes being conductive. |
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Re: PCB through hole activation for copper plating
I did have an idea, which may or may not work:
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It's not a replacement for plated through holes, but may address the same problem. I was working on a strictly mechanical basis, which meant eyelets or jumper wires Eyelets have a history of being badly soldered and not being as permanent as people would want. What I thought of was an automated system that would push a piece of soft copper wire into a hole. From the bottom it would be center punched to swage it in the hole (and it wouldn't be flush) Then at the top, cut off a bit above flush, and swaged to cover the top pad as much as possible. What I'm thinking of is effectively a solid rivet. While I was thinking of this reply, I thought that a wire protuded through the board, then bent at right angles. Then at the top, cut off the wire above the surface (distance matters!), then bend the wire over to make a C shaped jumper between top and bottom layers. The idea is that this could be automated with a special setup that had the appropriate wire benders as needed. Solder that, and you've got a better solution, I think. Harvey On 6/12/2020 6:53 PM, Jim Higgins wrote:
Received from Matheus Costa via groups.io at 6/12/2020 15:16 UTC:There are another method that don't use calcium hypophosphite. It's in this site (in portuguese, but google translate can be effective to get the essential): |
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Re: PCB through hole activation for copper plating
Jim Higgins
Received from Matheus Costa via groups.io at 6/12/2020 15:16 UTC:
There are another method that don't use calcium hypophosphite. It's in this site (in portuguese, but google translate can be effective to get the essential): The method at this site starts with Sodium Hypophosphite, which is as much a controlled substance as Calcium Hypophosphite. Jim H |
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Re: PCB through hole activation for copper plating
Thanks everyone for your replies and sugestions.
Thanks, Matheus!? While not exactly what I was hoping for, this is a reasonable solution.? I will give a shot at trying to "make" calcium hypophosphite.? Been a looong time since I dabbled in chemistry but maybe it is like riding a bicycle and you never forget how! And, for anyone who cares, calcium hypophosphite is available from several vendors on alibaba.? They all advertise the stuff for pennies per gram but when you request a quote all of them come back in the neighborhood of $100 per 500G.? Then when you tell them you are in the US, the price jumps up to about $500 per 500G.? This is well beyond the range of most hobbyists...at least well beyond mine.? Now I am off to price diy calcium hypophosphite! Thanks again! |
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Re: PCB through hole activation for copper plating
There are another method that don't use calcium hypophosphite. It's in this site (in portuguese, but google translate can be effective to get the essential): Anyway, in that site there are a homebrew solution to manufacture calcium hypophosphite too. Best regards Matheus
On Thursday, June 11, 2020, 9:19:23 PM GMT-3, Terry Gray <twgray2007@...> wrote:
There is an Instructable on this very subject. I have had no luck with the conductive ink or paint method, never getting close to 95%, which is why I am inquiring about the chemical method. If I can't obtain Calcium Hypophosphite then I would like to find an alternative chemical method that doesn't require it. |
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Re: PCB through hole activation for copper plating
Jim Higgins
You know what? You asked a question and I answered on point... and then amplified separately in hopes of helping. You are no worse off now than you were when you started, but now you act like I'm a problem. Google is your friend.
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Jim H Received from Terry Gray at 6/12/2020 00:13 UTC: Thanks for your suggestions but did you read where I am specifically asking about "through-hole activation" and not for alternatives? I have used eyelets but really don't like them due to a too large hole size requirement. I have also gone the soldered wire route but that is only good for vias, and useless for connectors. |
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Re: PCB through hole activation for copper plating
An electroplating shop might be cool and give you a small amount. On Thu, Jun 11, 2020 at 1:37 PM Charlie Hansen <n0tt1@...> wrote: One might also check out the jewelry sellers on ""....I purchased |
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Re: PCB through hole activation for copper plating
There is an Instructable on this very subject.
I have had no luck with the conductive ink or paint method, never getting close to 95%, which is why I am inquiring about the chemical method. If I can't obtain Calcium Hypophosphite then I would like to find an alternative chemical method that doesn't require it. |
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Re: PCB through hole activation for copper plating
Thanks for your suggestions but did you read where? I am specifically asking about "through-hole activation" and not for alternatives?? I have used eyelets but really don't like them due to a too large hole size requirement.? I have also gone the soldered wire route but that is only good for vias, and useless for connectors.
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Re: PCB through hole activation for copper plating
One might also check out the jewelry sellers on "etsy.com"....I purchased
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some VERY tiny brass rivets on a site (sorry, no link...Google) and they also had eyelets. Charlie On Thu, 11 Jun 2020 17:29:51 +0000 "Jim Higgins" <HigginsJ@...> writes:
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Bertho
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