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Joseph Hebert
04/28/12 16:46
Read: 1086 times
Okemah, Ok
United States


 
#187267 - plating holes
Responding to: Mahmood Elnasser's previous message
Hi Mahmood,

The short answer is, no. There is no easy way to do plated through holes. But there are ways it can be done.

Obviously you can set up to do electroplating. But if you do you need to know a couple of things. First, you'll need an "activator" to make the holes platable. That's why it's important not to use dull bits that just burn their way through the FR4. You need clean holes for the activator to work. Basically, activator is just carbon particles in liquid. You dip the board in the liguid and squeegee it off the surfaces. As the liquid dries from the holes it leaves behind a layer of carbon which can be plated.

The second thing you'll need to know is a technique called reverse pulse plating. Espeially if you have high aspect ratio holes (l >> d), you need to read up on this.

Of course, you'll also need to know the various chemistries you'll use, plating solutions, etc., but that stuff is easy enough to find.

It happens that, as we speak, I am doing the ground work to start plating my through holes. Since I recently finished building a lamination press and can now produce multi-layer boards, I need to make the change. I've been using a conductive epoxy to "plate" my through holes. It's a paste that you smear over the panel while a vacuum table sucks the paste through the holes. Then you bake the panel at 160C for a half hour and you've got continuity.

The problem is that the paste is very expensive, and it only works well for 2 to 4 layer boards. You might be able to get a 6-layer done, but I wouldn't take any bets. If you're only going to do 2-layer boards this is a good alternative. If you're going to do multi-layer boards, go ahead and set up to electroplate.

One more thing. Whether you electroplate or use conductive epoxy, you will need to put a stop, a protective membrane, on the surfaces of your board before you drill the holes. I use a clear plastic that I buy from a library supply store. It comes in rolls 18" wide (just wide enough to cover both sides of my 9" x 12" panels) with adhesive on one side. It's intended to put on the covers of books to protect them.

Good luck,

Joe

List of 74 messages in thread
TopicAuthorDate
CNC      Mahmood Elnasser      04/14/12 10:43      
   Enjoy :)      Oliver Sedlacek      04/16/12 04:14      
      Having fun      Mahmood Elnasser      04/17/12 13:53      
   Congratulations      Joseph Hebert      04/16/12 09:42      
      We looked at buying one of those      Jez Smith      04/16/12 14:09      
         Me Either!      Joseph Hebert      04/16/12 14:17      
            We use a variety      Jez Smith      04/17/12 00:50      
               do not be lazy,Mr.Smith      Stefan KAnev      04/17/12 11:28      
               prototype cost and turnaround      Joseph Hebert      04/17/12 13:31      
                  I'll find the ads      Erik Malund      04/17/12 14:14      
                     googled      Erik Malund      04/17/12 14:22      
                        Ebay deal      Steve M. Taylor      04/17/12 15:08      
                           What about this one then...        Robert Revens      04/25/12 12:59      
                              Follow up on prototype board shops      Joseph Hebert      06/22/12 08:41      
                                 international pcb houses      Mahmood Elnasser      06/22/12 14:13      
                                    PCB Houses      Joseph Hebert      06/22/12 16:55      
            working out of town      Erik Malund      04/17/12 07:20      
      CNC bits      Mahmood Elnasser      04/25/12 06:37      
         answering      Joseph Hebert      04/25/12 11:38      
            it happens      Mahmood Elnasser      04/25/12 14:51      
               what other tools required?      Mahmood Elnasser      04/25/12 15:00      
                  a new trick zeroing Z axis      Mahmood Elnasser      04/26/12 12:26      
                     Z ref      Steve M. Taylor      04/26/12 13:10      
                        Collet type      Mahmood Elnasser      06/22/12 14:27      
                        Z axis reference      Mahmood Elnasser      07/02/12 01:40      
                           Vacuum      Per Westermark      07/02/12 02:35      
               this sort of thing happens often, from my experience      Richard Erlacher      05/01/12 07:38      
                  ctrl+A, crtl+C, submit      David Brown      09/19/12 01:34      
         tools      Joseph Hebert      04/26/12 14:11      
            holding the PCB      Mahmood Elnasser      04/27/12 00:27      
               Holding the PCB      Joseph Hebert      04/27/12 14:06      
                  Carbon steel?      Per Westermark      04/27/12 20:16      
                     Not tungsten carbide      Joseph Hebert      04/28/12 16:37      
                        Just carbide is a bit lazy slang for tungsten carbide      Per Westermark      04/28/12 21:41      
                           If you say so.      Joseph Hebert      04/28/12 22:30      
                  Plate through holes      Mahmood Elnasser      04/28/12 11:05      
                     plating holes      Joseph Hebert      04/28/12 16:46      
                     plated through holes cont.      Joseph Hebert      04/28/12 22:37      
                  2 point registration system      Mahmood Elnasser      04/30/12 14:27      
                     Need not be exactly in middle.      Per Westermark      04/30/12 16:05      
                        is it that simple?      Mahmood Elnasser      05/01/12 00:27      
                     2-pin registration      Joseph Hebert      04/30/12 23:40      
                     Fine pitch milling      Joseph Hebert      05/01/12 23:54      
                        Solder Mask      Mahmood Elnasser      05/02/12 10:28      
                           solder mask and legend      Joseph Hebert      05/02/12 11:47      
                              too much work      Mahmood Elnasser      05/02/12 15:54      
                                 Much work      Joseph Hebert      05/06/12 15:50      
                                    My CNC      Steve M. Taylor      05/07/12 06:57      
                                       Is That...      Michael Karas      05/07/12 10:30      
                                       which cad did you use?      Mahmood Elnasser      05/07/12 15:58      
                                          Limit Switches      Michael Karas      05/08/12 00:22      
                                             Will do      Mahmood Elnasser      05/08/12 10:55      
                                                Little Plates      Michael Karas      05/08/12 16:40      
                                             MEchanical limit switches      Steve M. Taylor      05/11/12 12:50      
                                       Your project      Joseph Hebert      05/10/12 06:18      
                                          This:      Steve M. Taylor      05/11/12 12:38      
                                             very cool!      Joseph Hebert      05/11/12 13:29      
                                             Funnel      Michael Karas      05/12/12 12:37      
                                                Funnel !      Steve M. Taylor      05/13/12 13:04      
                                                   Lawyer or Solicitor - Not ! !      Michael Karas      05/13/12 15:43      
                                                      RIght      Steve M. Taylor      05/14/12 12:16      
                                    vacuum pick and place tool      David Brown      09/19/12 01:29      
            90 degrees bits      Mahmood Elnasser      09/14/12 04:22      
               Z-axis depth control      Joseph Hebert      09/15/12 22:53      
                  stepper       Mahmood Elnasser      09/16/12 06:34      
                     z-axis control      Joseph Hebert      09/16/12 15:37      
   oiling      Mahmood Elnasser      09/29/12 14:49      
      lubrication      Joseph Hebert      10/01/12 10:41      
      Lube      Steve M. Taylor      10/05/12 14:47      
         ballscrews      Mahmood Elnasser      10/06/12 00:21      
            Ballscrews      Steve M. Taylor      10/06/12 14:00      
               Sometimes it's useful for controlling dynamics      Richard Erlacher      10/06/12 14:08      
            ballscrews & table slides      Joseph Hebert      10/06/12 15:15      
   LINUXCNC      Mahmood Elnasser      10/19/12 02:08      

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