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Some SMT opinions

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  • AI2Q
    KB1GTT and myself have been making up dozens of very small PCBs using 1206- and 0603-sized SMT parts, and we have been using a homebrew reflow oven made from a
    Message 1 of 8 , Jul 29, 2011
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      KB1GTT and myself have been making up dozens of very small PCBs using 1206- and 0603-sized SMT parts, and we have been using a homebrew reflow oven made from a Black and Decker infrared toaster oven. It's heating element is controlled with a 40A solid-state relay through a controller board connected to my PC with a USB connection. We use solder paste.
       
      The TechFX software we use runs under XP and gives you a way to set a variety of profiles (preheat, soak, reflow, cooldown). What's neat is that you can graphically watch the controller in action, thanks to its closed loop operation using a thermocouple detector inside the oven.
       
      While this set-up is FB for production runs, I would not recommend reflow for any one-off ham project such as a Softrock PCB. The reason? Well, if there should be an error, such as tombstoning (where a small SMT part stands up on edge), or movement of a fine-pitch SMD device, then the board must be reworked. Yes, you can rework just that part that needs attention, but sometimes a board can have multiple faults. Rework can be tough.
       
      I would recommend going at it the old fashioned way, namely one part at a time, testing as you go as per Robby's notes. Use ordinary solder and ChipQuik flux from a syringe.
       
      By the way, my daily transceiver is a G3XJP design PIC-a-STAR, using hundreds of SMT devices on many PCBs. It was all assembled by hand. ChipQuik is key to both successful soldering and rework. Fabulous stuff.
       
      Vy 73, AI2Q, Alex
      Member: ARRL, FOC, RSGB, CWops, QRP-L, Antique Wireless Association, Wide Area Amateur Radio Network, New England Radio Discussion Society (NERDS)
      http://home.roadrunner.com/~alexmm
       
      ----- Original Message -----
      Sent: Thursday, July 28, 2011 1:21 PM
      Subject: Re: [softrock40] Do all SMT first on RXTX?

       

      I too have used the cup warmer/hot air approach on two Lite's and I working on another lite and a couple Ensemble RXs. I do the hot air by hand.

      One thing I ran into on the Ensemble RX is that the board was too big for my cup warmer. Luckily our stove is one of the glass tops, so I used an IR thermometer to set the temp of one of the 'burners' to the same as the cup warmer (about 230 degF). Worked just great.

      I use a syringe to apply the solder paste and the only problem I've had is that I am too stingy with the paste for the multi-pin devices, so I often have to go touch up a pin or two. I use a high power eye loupe to inspect all the connections before proceeding.

      73,
      ...jerry
      KA6HLD

      On Thu, Jul 28, 2011 at 8:24 AM, MIKE DURKIN <Patriot121@...> wrote:
       

      when you do the hot air part ... do you do it by hand or do you use a stand ?

      Mike KC7NOA
    • cbayona
      I bought a TechFx 2.0 controller some time back but I never was too happy with it, it had several issues and the company never gave me a solution and now they
      Message 2 of 8 , Jul 29, 2011
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        I bought a TechFx 2.0 controller some time back but I never was too happy with it, it had several issues and the company never gave me a solution and now they are gone. When moving recently I found the controller and the thermocouples so I'm interested in getting something working, presently I do manual control of the oven.

        I recently watched a video of the controller soldering a BGA chip and the temperature profile was a thing of beauty, mine was nothing like that, the temperature would go up to the soaking temperature, overshoot then proceed to the reflow zone and overshoot that. The company is gone so I can't update my firmware or software so I'm stuck, maybe an Infra-wave oven would help.
         
        I recently ended buying a Infra-wave oven because of its quicker response, but I made an error, I cooked food with it before I even got around to using it to solder boards so now I will need to buy another one because the current one is not about to leave my kitchen, I love it for cooking.

        I been fooling around with the idea of building another controller with my own hardware and software, the hardware is working (ATMEGA168) but the software it's a work once in a blue while project, I'm trying to figure out the PID controller portion and how to make it work like I want it to and anticipate the overshoot.

        At 08:24 AM 7/29/2011, you wrote:

         
        KB1GTT and myself have been making up dozens of very small PCBs using 1206- and 0603-sized SMT parts, and we have been using a homebrew reflow oven made from a Black and Decker infrared toaster oven. It's heating element is controlled with a 40A solid-state relay through a controller board connected to my PC with a USB connection. We use solder paste.
         
        The TechFX software we use runs under XP and gives you a way to set a variety of profiles (preheat, soak, reflow, cooldown). What's neat is that you can graphically watch the controller in action, thanks to its closed loop operation using a thermocouple detector inside the oven.
         
        While this set-up is FB for production runs, I would not recommend reflow for any one-off ham project such as a Softrock PCB. The reason? Well, if there should be an error, such as tombstoning (where a small SMT part stands up on edge), or movement of a fine-pitch SMD device, then the board must be reworked. Yes, you can rework just that part that needs attention, but sometimes a board can have multiple faults. Rework can be tough.
         
        I would recommend going at it the old fashioned way, namely one part at a time, testing as you go as per Robby's notes. Use ordinary solder and ChipQuik flux from a syringe.
         
        By the way, my daily transceiver is a G3XJP design PIC-a-STAR, using hundreds of SMT devices on many PCBs. It was all assembled by hand. ChipQuik is key to both successful soldering and rework. Fabulous stuff.
         
        Vy 73, AI2Q, Alex
        Member: ARRL, FOC, RSGB, CWops, QRP-L, Antique Wireless Association, Wide Area Amateur Radio Network, New England Radio Discussion Society (NERDS)
        http://home.roadrunner.com/~alexmm
         
        SNIP

        Cecil
        k5nwa
        www.softrockradio.org > <  http://thepartsplace.k5nwa.com/   >
        http://parts.softrockradio.org/ >

        Never take life seriously. Nobody gets out alive anyway.

      • John D'Ausilio
        I also have and use an Infrawave oven .. I got the Spark-Fun controller which didn t work at all when I got it; the display timing was fubar, and the relay was
        Message 3 of 8 , Jul 29, 2011
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          I also have and use an Infrawave oven .. I got the Spark-Fun controller which didn't work at all when I got it; the display timing was fubar, and the relay was the wrong coil voltage. I fixed the firmware and hacked the board a bit and now it works great .. haven't tried BGA but I've done some 64-LFCSP (AD9912) and had no issues at all.

          de w1rt/john

          On Fri, Jul 29, 2011 at 11:51 AM, cbayona <CBayona@...> wrote:


          I bought a TechFx 2.0 controller some time back but I never was too happy with it, it had several issues and the company never gave me a solution and now they are gone. When moving recently I found the controller and the thermocouples so I'm interested in getting something working, presently I do manual control of the oven.

          I recently watched a video of the controller soldering a BGA chip and the temperature profile was a thing of beauty, mine was nothing like that, the temperature would go up to the soaking temperature, overshoot then proceed to the reflow zone and overshoot that. The company is gone so I can't update my firmware or software so I'm stuck, maybe an Infra-wave oven would help.
           
          I recently ended buying a Infra-wave oven because of its quicker response, but I made an error, I cooked food with it before I even got around to using it to solder boards so now I will need to buy another one because the current one is not about to leave my kitchen, I love it for cooking.

          I been fooling around with the idea of building another controller with my own hardware and software, the hardware is working (ATMEGA168) but the software it's a work once in a blue while project, I'm trying to figure out the PID controller portion and how to make it work like I want it to and anticipate the overshoot.


          At 08:24 AM 7/29/2011, you wrote:

           
          KB1GTT and myself have been making up dozens of very small PCBs using 1206- and 0603-sized SMT parts, and we have been using a homebrew reflow oven made from a Black and Decker infrared toaster oven. It's heating element is controlled with a 40A solid-state relay through a controller board connected to my PC with a USB connection. We use solder paste.
           
          The TechFX software we use runs under XP and gives you a way to set a variety of profiles (preheat, soak, reflow, cooldown). What's neat is that you can graphically watch the controller in action, thanks to its closed loop operation using a thermocouple detector inside the oven.
           
          While this set-up is FB for production runs, I would not recommend reflow for any one-off ham project such as a Softrock PCB. The reason? Well, if there should be an error, such as tombstoning (where a small SMT part stands up on edge), or movement of a fine-pitch SMD device, then the board must be reworked. Yes, you can rework just that part that needs attention, but sometimes a board can have multiple faults. Rework can be tough.
           
          I would recommend going at it the old fashioned way, namely one part at a time, testing as you go as per Robby's notes. Use ordinary solder and ChipQuik flux from a syringe.
           
          By the way, my daily transceiver is a G3XJP design PIC-a-STAR, using hundreds of SMT devices on many PCBs. It was all assembled by hand. ChipQuik is key to both successful soldering and rework. Fabulous stuff.
           
          Vy 73, AI2Q, Alex
          Member: ARRL, FOC, RSGB, CWops, QRP-L, Antique Wireless Association, Wide Area Amateur Radio Network, New England Radio Discussion Society (NERDS)
          http://home.roadrunner.com/~alexmm
           
          SNIP

          Cecil
          k5nwa
          www.softrockradio.org > <  http://thepartsplace.k5nwa.com/   >
          http://parts.softrockradio.org/ >

          Never take life seriously. Nobody gets out alive anyway.



        • cbayona
          They don t have their own software but they have links to other people software so that can be an issue as you found out. I looked at their controller before
          Message 4 of 8 , Jul 29, 2011
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            They don't have their own software but they have links to other people software so that can be an issue as you found out. I looked at their controller before but I already had hardware available. If I have to write my own software, I prefer AVR, TI's MSP430, or ARM because of it price/performance ratio.

            My problem is not the hardware I have the TechFX, and my own AVR hardware available, the problem is the software. Upon looking in the Internet I see people describing the same problem that I encountered but some reported it being fixed with more recent software versions. The problem is that after looking for hours I could not find any copies of the software anywhere, never mind more recent versions that fixes the issues.

            I was looking at making available a SoftRock like device all assembled and all SMT but if I had to buy a commercial oven that would make the project a little too expensive so it's on hold for now.

            If I could get the software updates for the TechFX it looks like it would work rather well, see a BGA done with that controller done last year.
            http://www.youtube.com/watch?v=ypQAPyiAsJA  > That is a Infra-wave oven for sure, with the controller doing a wonderful job.

            If anyone has a recent copy of the software for the PC and Firmware for the board I sure would be interested in getting a copy.

            At 11:09 AM 7/29/2011, you wrote:


            I also have and use an Infrawave oven .. I got the Spark-Fun controller which didn't work at all when I got it; the display timing was fubar, and the relay was the wrong coil voltage. I fixed the firmware and hacked the board a bit and now it works great .. haven't tried BGA but I've done some 64-LFCSP (AD9912) and had no issues at all.

            de w1rt/john

            On Fri, Jul 29, 2011 at 11:51 AM, cbayona <CBayona@...> wrote:


            I bought a TechFx 2.0 controller some time back but I never was too happy with it, it had several issues and the company never gave me a solution and now they are gone. When moving recently I found the controller and the thermocouples so I'm interested in getting something working, presently I do manual control of the oven.

            I recently watched a video of the controller soldering a BGA chip and the temperature profile was a thing of beauty, mine was nothing like that, the temperature would go up to the soaking temperature, overshoot then proceed to the reflow zone and overshoot that. The company is gone so I can't update my firmware or software so I'm stuck, maybe an Infra-wave oven would help.
             
            I recently ended buying a Infra-wave oven because of its quicker response, but I made an error, I cooked food with it before I even got around to using it to solder boards so now I will need to buy another one because the current one is not about to leave my kitchen, I love it for cooking.

            I been fooling around with the idea of building another controller with my own hardware and software, the hardware is working (ATMEGA168) but the software it's a work once in a blue while project, I'm trying to figure out the PID controller portion and how to make it work like I want it to and anticipate the overshoot.


            At 08:24 AM 7/29/2011, you wrote:

             
            KB1GTT and myself have been making up dozens of very small PCBs using 1206- and 0603-sized SMT parts, and we have been using a homebrew reflow oven made from a Black and Decker infrared toaster oven. It's heating element is controlled with a 40A solid-state relay through a controller board connected to my PC with a USB connection. We use solder paste.
             
            The TechFX software we use runs under XP and gives you a way to set a variety of profiles (preheat, soak, reflow, cooldown). What's neat is that you can graphically watch the controller in action, thanks to its closed loop operation using a thermocouple detector inside the oven.
             
            While this set-up is FB for production runs, I would not recommend reflow for any one-off ham project such as a Softrock PCB. The reason? Well, if there should be an error, such as tombstoning (where a small SMT part stands up on edge), or movement of a fine-pitch SMD device, then the board must be reworked. Yes, you can rework just that part that needs attention, but sometimes a board can have multiple faults. Rework can be tough.
             
            I would recommend going at it the old fashioned way, namely one part at a time, testing as you go as per Robby's notes. Use ordinary solder and ChipQuik flux from a syringe.
             
            By the way, my daily transceiver is a G3XJP design PIC-a-STAR, using hundreds of SMT devices on many PCBs. It was all assembled by hand. ChipQuik is key to both successful soldering and rework. Fabulous stuff.
             
            Vy 73, AI2Q, Alex
            Member: ARRL, FOC, RSGB, CWops, QRP-L, Antique Wireless Association, Wide Area Amateur Radio Network, New England Radio Discussion Society (NERDS)
            http://home.roadrunner.com/~alexmm
             
            SNIP

            Cecil
            k5nwa
            www.softrockradio.org > <  http://thepartsplace.k5nwa.com/  >
            http://parts.softrockradio.org/ >

            Never take life seriously. Nobody gets out alive anyway.




            Cecil
            k5nwa
            www.softrockradio.org > <  http://thepartsplace.k5nwa.com/   >
            http://parts.softrockradio.org/ >

            Never take life seriously. Nobody gets out alive anyway.

          • Allen West
            Where do you get solder paste and an IR thermometer?  When I google for paste I keep coming up with the gallon size. From: AI2Q To:
            Message 5 of 8 , Jul 30, 2011
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              Where do you get solder paste and an IR thermometer?  When I google for paste I keep coming up with the gallon size.

              From: AI2Q <ai2q@...>
              To: softrock40@yahoogroups.com
              Sent: Friday, July 29, 2011 9:24 AM
              Subject: [softrock40] Some SMT opinions

               
               
              KB1GTT and myself have been making up dozens of very small PCBs using 1206- and 0603-sized SMT parts, and we have been using a homebrew reflow oven made from a Black and Decker infrared toaster oven. It's heating element is controlled with a 40A solid-state relay through a controller board connected to my PC with a USB connection. We use solder paste.
               
              The TechFX software we use runs under XP and gives you a way to set a variety of profiles (preheat, soak, reflow, cooldown). What's neat is that you can graphically watch the controller in action, thanks to its closed loop operation using a thermocouple detector inside the oven.
               
              While this set-up is FB for production runs, I would not recommend reflow for any one-off ham project such as a Softrock PCB. The reason? Well, if there should be an error, such as tombstoning (where a small SMT part stands up on edge), or movement of a fine-pitch SMD device, then the board must be reworked. Yes, you can rework just that part that needs attention, but sometimes a board can have multiple faults. Rework can be tough.
               
              I would recommend going at it the old fashioned way, namely one part at a time, testing as you go as per Robby's notes. Use ordinary solder and ChipQuik flux from a syringe.
               
              By the way, my daily transceiver is a G3XJP design PIC-a-STAR, using hundreds of SMT devices on many PCBs. It was all assembled by hand. ChipQuik is key to both successful soldering and rework. Fabulous stuff.
               
              Vy 73, AI2Q, Alex
              Member: ARRL, FOC, RSGB, CWops, QRP-L, Antique Wireless Association, Wide Area Amateur Radio Network, New England Radio Discussion Society (NERDS)
              http://home.roadrunner.com/~alexmm
               
              ----- Original Message -----
              Sent: Thursday, July 28, 2011 1:21 PM
              Subject: Re: [softrock40] Do all SMT first on RXTX?

               
              I too have used the cup warmer/hot air approach on two Lite's and I working on another lite and a couple Ensemble RXs. I do the hot air by hand.

              One thing I ran into on the Ensemble RX is that the board was too big for my cup warmer. Luckily our stove is one of the glass tops, so I used an IR thermometer to set the temp of one of the 'burners' to the same as the cup warmer (about 230 degF). Worked just great.

              I use a syringe to apply the solder paste and the only problem I've had is that I am too stingy with the paste for the multi-pin devices, so I often have to go touch up a pin or two. I use a high power eye loupe to inspect all the connections before proceeding.

              73,
              ...jerry
              KA6HLD

              On Thu, Jul 28, 2011 at 8:24 AM, MIKE DURKIN <Patriot121@...> wrote:
               
              when you do the hot air part ... do you do it by hand or do you use a stand ?

              Mike KC7NOA


            • William Dillon
              http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=1310838&k=solder%20paste You can get a cheap IR thermo at Harbor Freight
              Message 6 of 8 , Jul 30, 2011
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                http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=1310838&k=solder%20paste

                You can get a cheap IR thermo at Harbor Freight

                On Jul 30, 2011, at 4:57 PM, Allen West wrote:

                 

                Where do you get solder paste and an IR thermometer?  When I google for paste I keep coming up with the gallon size.

                From: AI2Q <ai2q@...>
                To: softrock40@yahoogroups.com
                Sent: Friday, July 29, 2011 9:24 AM
                Subject: [softrock40] Some SMT opinions

                 
                 
                KB1GTT and myself have been making up dozens of very small PCBs using 1206- and 0603-sized SMT parts, and we have been using a homebrew reflow oven made from a Black and Decker infrared toaster oven. It's heating element is controlled with a 40A solid-state relay through a controller board connected to my PC with a USB connection. We use solder paste.
                 
                The TechFX software we use runs under XP and gives you a way to set a variety of profiles (preheat, soak, reflow, cooldown). What's neat is that you can graphically watch the controller in action, thanks to its closed loop operation using a thermocouple detector inside the oven.
                 
                While this set-up is FB for production runs, I would not recommend reflow for any one-off ham project such as a Softrock PCB. The reason? Well, if there should be an error, such as tombstoning (where a small SMT part stands up on edge), or movement of a fine-pitch SMD device, then the board must be reworked. Yes, you can rework just that part that needs attention, but sometimes a board can have multiple faults. Rework can be tough.
                 
                I would recommend going at it the old fashioned way, namely one part at a time, testing as you go as per Robby's notes. Use ordinary solder and ChipQuik flux from a syringe.
                 
                By the way, my daily transceiver is a G3XJP design PIC-a-STAR, using hundreds of SMT devices on many PCBs. It was all assembled by hand. ChipQuik is key to both successful soldering and rework. Fabulous stuff.
                 
                Vy 73, AI2Q, Alex
                Member: ARRL, FOC, RSGB, CWops, QRP-L, Antique Wireless Association, Wide Area Amateur Radio Network, New England Radio Discussion Society (NERDS)
                http://home.roadrunner.com/~alexmm
                 
                ----- Original Message -----
                Sent: Thursday, July 28, 2011 1:21 PM
                Subject: Re: [softrock40] Do all SMT first on RXTX?

                 
                I too have used the cup warmer/hot air approach on two Lite's and I working on another lite and a couple Ensemble RXs. I do the hot air by hand.

                One thing I ran into on the Ensemble RX is that the board was too big for my cup warmer. Luckily our stove is one of the glass tops, so I used an IR thermometer to set the temp of one of the 'burners' to the same as the cup warmer (about 230 degF). Worked just great.

                I use a syringe to apply the solder paste and the only problem I've had is that I am too stingy with the paste for the multi-pin devices, so I often have to go touch up a pin or two. I use a high power eye loupe to inspect all the connections before proceeding.

                73,
                ...jerry
                KA6HLD

                On Thu, Jul 28, 2011 at 8:24 AM, MIKE DURKIN <Patriot121@...> wrote:
                 
                when you do the hot air part ... do you do it by hand or do you use a stand ?

                Mike KC7NOA




              • Jerry Dunmire
                I get my solder paste in a syringe from KD5SSJ: http://www.kd5ssj.com/solderpaste Lots of choices for the IR thermometers. I think mine is from Frys, but try
                Message 7 of 8 , Jul 30, 2011
                • 0 Attachment
                  I get my solder paste in a syringe from KD5SSJ:
                  http://www.kd5ssj.com/solderpaste

                  Lots of choices for the IR thermometers. I think mine is from Frys, but try Amazon.

                  73,
                  ...jerry
                  KA6HLD

                  On Sat, Jul 30, 2011 at 4:57 PM, Allen West <kb4ra@...> wrote:
                   

                  Where do you get solder paste and an IR thermometer?  When I google for paste I keep coming up with the gallon size.

                  From: AI2Q <ai2q@...>
                  To: softrock40@yahoogroups.com
                  Sent: Friday, July 29, 2011 9:24 AM
                  Subject: [softrock40] Some SMT opinions

                   
                   
                  KB1GTT and myself have been making up dozens of very small PCBs using 1206- and 0603-sized SMT parts, and we have been using a homebrew reflow oven made from a Black and Decker infrared toaster oven. It's heating element is controlled with a 40A solid-state relay through a controller board connected to my PC with a USB connection. We use solder paste.
                   
                  The TechFX software we use runs under XP and gives you a way to set a variety of profiles (preheat, soak, reflow, cooldown). What's neat is that you can graphically watch the controller in action, thanks to its closed loop operation using a thermocouple detector inside the oven.
                   
                  While this set-up is FB for production runs, I would not recommend reflow for any one-off ham project such as a Softrock PCB. The reason? Well, if there should be an error, such as tombstoning (where a small SMT part stands up on edge), or movement of a fine-pitch SMD device, then the board must be reworked. Yes, you can rework just that part that needs attention, but sometimes a board can have multiple faults. Rework can be tough.
                   
                  I would recommend going at it the old fashioned way, namely one part at a time, testing as you go as per Robby's notes. Use ordinary solder and ChipQuik flux from a syringe.
                   
                  By the way, my daily transceiver is a G3XJP design PIC-a-STAR, using hundreds of SMT devices on many PCBs. It was all assembled by hand. ChipQuik is key to both successful soldering and rework. Fabulous stuff.
                   
                  Vy 73, AI2Q, Alex
                  Member: ARRL, FOC, RSGB, CWops, QRP-L, Antique Wireless Association, Wide Area Amateur Radio Network, New England Radio Discussion Society (NERDS)
                  http://home.roadrunner.com/~alexmm
                   
                  ----- Original Message -----
                  Sent: Thursday, July 28, 2011 1:21 PM
                  Subject: Re: [softrock40] Do all SMT first on RXTX?

                   
                  I too have used the cup warmer/hot air approach on two Lite's and I working on another lite and a couple Ensemble RXs. I do the hot air by hand.

                  One thing I ran into on the Ensemble RX is that the board was too big for my cup warmer. Luckily our stove is one of the glass tops, so I used an IR thermometer to set the temp of one of the 'burners' to the same as the cup warmer (about 230 degF). Worked just great.

                  I use a syringe to apply the solder paste and the only problem I've had is that I am too stingy with the paste for the multi-pin devices, so I often have to go touch up a pin or two. I use a high power eye loupe to inspect all the connections before proceeding.

                  73,
                  ...jerry
                  KA6HLD

                  On Thu, Jul 28, 2011 at 8:24 AM, MIKE DURKIN <Patriot121@...> wrote:
                   
                  when you do the hot air part ... do you do it by hand or do you use a stand ?

                  Mike KC7NOA



                • Jorge Macias
                  I bought in ebay http://cgi.ebay.com/1pcs-50g-MCN-300-Soldering-Solder-Paste-63-37-25-45um-/200598351069?pt=LH_DefaultDomain_0&hash=item2eb497ecdd and the
                  Message 8 of 8 , Aug 1, 2011
                  • 0 Attachment
                    I bought in ebay
                    and the thermometer
                    http://cgi.ebay.com/Non-Contact-IR-Laser-Infrared-Digital-Thermometer-New-/170632896688?pt=LH_DefaultDomain_0&hash=item27ba8360b0#ht_4743wt_805

                    On Sat, Jul 30, 2011 at 6:57 PM, Allen West <kb4ra@...> wrote:
                     

                    Where do you get solder paste and an IR thermometer?  When I google for paste I keep coming up with the gallon size.

                    From: AI2Q <ai2q@...>
                    To: softrock40@yahoogroups.com
                    Sent: Friday, July 29, 2011 9:24 AM
                    Subject: [softrock40] Some SMT opinions

                     
                     
                    KB1GTT and myself have been making up dozens of very small PCBs using 1206- and 0603-sized SMT parts, and we have been using a homebrew reflow oven made from a Black and Decker infrared toaster oven. It's heating element is controlled with a 40A solid-state relay through a controller board connected to my PC with a USB connection. We use solder paste.
                     
                    The TechFX software we use runs under XP and gives you a way to set a variety of profiles (preheat, soak, reflow, cooldown). What's neat is that you can graphically watch the controller in action, thanks to its closed loop operation using a thermocouple detector inside the oven.
                     
                    While this set-up is FB for production runs, I would not recommend reflow for any one-off ham project such as a Softrock PCB. The reason? Well, if there should be an error, such as tombstoning (where a small SMT part stands up on edge), or movement of a fine-pitch SMD device, then the board must be reworked. Yes, you can rework just that part that needs attention, but sometimes a board can have multiple faults. Rework can be tough.
                     
                    I would recommend going at it the old fashioned way, namely one part at a time, testing as you go as per Robby's notes. Use ordinary solder and ChipQuik flux from a syringe.
                     
                    By the way, my daily transceiver is a G3XJP design PIC-a-STAR, using hundreds of SMT devices on many PCBs. It was all assembled by hand. ChipQuik is key to both successful soldering and rework. Fabulous stuff.
                     
                    Vy 73, AI2Q, Alex
                    Member: ARRL, FOC, RSGB, CWops, QRP-L, Antique Wireless Association, Wide Area Amateur Radio Network, New England Radio Discussion Society (NERDS)
                    http://home.roadrunner.com/~alexmm
                     
                    ----- Original Message -----
                    Sent: Thursday, July 28, 2011 1:21 PM
                    Subject: Re: [softrock40] Do all SMT first on RXTX?

                     
                    I too have used the cup warmer/hot air approach on two Lite's and I working on another lite and a couple Ensemble RXs. I do the hot air by hand.

                    One thing I ran into on the Ensemble RX is that the board was too big for my cup warmer. Luckily our stove is one of the glass tops, so I used an IR thermometer to set the temp of one of the 'burners' to the same as the cup warmer (about 230 degF). Worked just great.

                    I use a syringe to apply the solder paste and the only problem I've had is that I am too stingy with the paste for the multi-pin devices, so I often have to go touch up a pin or two. I use a high power eye loupe to inspect all the connections before proceeding.

                    73,
                    ...jerry
                    KA6HLD

                    On Thu, Jul 28, 2011 at 8:24 AM, MIKE DURKIN <Patriot121@...> wrote:
                     
                    when you do the hot air part ... do you do it by hand or do you use a stand ?

                    Mike KC7NOA



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