What to do to NOT get popcorned chip.

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • ktmmotocross
    Boardkiller
    • Feb 2014
    • 3553
    • slovakia

    #1

    What to do to NOT get popcorned chip.

    Hello. I desolder GPU 7600go and it popcorned. the chip was shorted so i throw it to can. But what can i do to not popocorned it. temp of couple when desolder was 230c and was on the chip in the middle, so it wasnt a high temp. also i preheated board
    Last edited by ktmmotocross; 06-29-2014, 05:26 AM.
  • Th3_uN1Qu3
    Believe in
    • Jul 2010
    • 6031
    • Romania

    #2
    Re: What to do to NOT get popcorned chip.

    Popcorning happens due two 2 main causes. 1 is moisture trapped inside the chip, this can be dried by baking the board at 80-90C for a few hours. 2 is too aggressive top heater. What rework station do you have?

    My personal preference is cranking the bottom heat high, even if it browns the board a bit. Just low enough that i don't get parts falling off. And do as little work with the top heat as possible.
    Originally posted by PeteS in CA
    Remember that by the time consequences of a short-sighted decision are experienced, the idiot who made the bad decision may have already been promoted or moved on to a better job at another company.
    A working TV? How boring!

    Comment

    • ktmmotocross
      Boardkiller
      • Feb 2014
      • 3553
      • slovakia

      #3
      Re: What to do to NOT get popcorned chip.

      have home build station with adjust hight of top heater and bottom heater to be not agressive. my reflow time is 2x longer then optimal profile to be not agressive with temp rising

      Comment

      • Th3_uN1Qu3
        Believe in
        • Jul 2010
        • 6031
        • Romania

        #4
        Re: What to do to NOT get popcorned chip.

        Maybe your reflow time is actually too long. Exact data would help.
        Originally posted by PeteS in CA
        Remember that by the time consequences of a short-sighted decision are experienced, the idiot who made the bad decision may have already been promoted or moved on to a better job at another company.
        A working TV? How boring!

        Comment

        • dellxps15
          Badcaps Legend
          • Feb 2014
          • 1585
          • italy

          #5
          Re: What to do to NOT get popcorned chip.

          do you use hot air top-bottom or full hybrid IR ?

          i have full ir and if i stay at 225° on the chip for more then 30 seconds it will popcorn. ive seen that many people suggest to put (for a full ir) a kapton on the top of the bga to prevent popcorning.

          baking and other operation are a bit too hard to do with normal staff (i dont have now a proper hooven)

          Comment

          • ktmmotocross
            Boardkiller
            • Feb 2014
            • 3553
            • slovakia

            #6
            Re: What to do to NOT get popcorned chip.

            i have 200W halogen as bottom heater and 400W IR bulb as top heater.
            top heater is pwm regulated and PID regulated

            Comment

            • tomodachi
              Badcaps Veteran
              • Apr 2012
              • 593
              • Turkey

              #7
              Re: What to do to NOT get popcorned chip.

              I guess 7600 is already faulty from factory. my multiple reflows or reballs with this chip got popcorned annoyingly, especially the one at toshiba a100. you can find a new revision of that chip and it will be ok.
              Last edited by tomodachi; 07-01-2014, 05:24 AM.

              Comment

              • Th3_uN1Qu3
                Believe in
                • Jul 2010
                • 6031
                • Romania

                #8
                Re: What to do to NOT get popcorned chip.

                Originally posted by ktmmotocross
                i have 200W halogen as bottom heater and 400W IR bulb as top heater.
                top heater is pwm regulated and PID regulated
                There you go. You have too little bottom heat. 600-800W would be preferred. I have 800W, have modified a toaster with PWM control and it does the job. I don't think i've ever used more than 300W with the hot air on top.

                And yes, more than 30 seconds above 220C will kill most chips. This is why i prefer to reball even new chips with leaded solder.
                Originally posted by PeteS in CA
                Remember that by the time consequences of a short-sighted decision are experienced, the idiot who made the bad decision may have already been promoted or moved on to a better job at another company.
                A working TV? How boring!

                Comment

                • ktmmotocross
                  Boardkiller
                  • Feb 2014
                  • 3553
                  • slovakia

                  #9
                  Re: What to do to NOT get popcorned chip.

                  my bottom is only 200W but can have no regulation and it preheat board to 150 in 9 minutes. i know it is slow but i think about preheat that slower is better. Or?

                  Comment

                  • sasser
                    Badcaps Veteran
                    • Dec 2012
                    • 364
                    • Malaysia

                    #10
                    Re: What to do to NOT get popcorned chip.

                    Pre bake for reduce risk popcorned chip.

                    Comment

                    • dellxps15
                      Badcaps Legend
                      • Feb 2014
                      • 1585
                      • italy

                      #11
                      Re: What to do to NOT get popcorned chip.

                      my question is: if humidity (water)boil at 100° celsius, why popcorning generally happen only over 200° celsius?....
                      second: a very small quantity of humidity, shouldnt evaporate as soon as che chip reach a temperature of 120-150° ?

                      for me popcorning is just the too high temperature exposion like anso the unique sayd. generally if i reach 225° for 5 seconds, i never get popcorn.

                      Comment

                      • SteveNielsen
                        Retired Tech
                        • Jun 2012
                        • 2327
                        • USA

                        #12
                        Re: What to do to NOT get popcorned chip.

                        At a high enough temperature the water is probably expanding faster than the plastic case can let it out.

                        Comment

                        • claudyu07
                          Claudyu07
                          • May 2014
                          • 164
                          • Ireland

                          #13
                          Re: What to do to NOT get popcorned chip.

                          I had same problem. Bake for 2 hrs at 100 degrees

                          Comment

                          • dellxps15
                            Badcaps Legend
                            • Feb 2014
                            • 1585
                            • italy

                            #14
                            Re: What to do to NOT get popcorned chip.

                            i did one today ( chip is 2010 )

                            note the kapton over the chip
                            Attached Files

                            Comment

                            • sasser
                              Badcaps Veteran
                              • Dec 2012
                              • 364
                              • Malaysia

                              #15
                              Re: What to do to NOT get popcorned chip.

                              pre bake is take time consuming are kapton tape method can replace this procedure? and im worried when use kapton tape the tantalum cap on bga were melt too and maybe dislodged because kapton tape not sticky at high tempreture.

                              Comment

                              • Th3_uN1Qu3
                                Believe in
                                • Jul 2010
                                • 6031
                                • Romania

                                #16
                                Re: What to do to NOT get popcorned chip.

                                I don't use tape of any kind over the chip and never had issues, but i'm using hot air.

                                The caps on top of the chip are ceramic not tantalum. They won't melt. If you accidentally move one or two off, they can always be put back in place with the hot air wand and appropriate nozzle. No problem.
                                Originally posted by PeteS in CA
                                Remember that by the time consequences of a short-sighted decision are experienced, the idiot who made the bad decision may have already been promoted or moved on to a better job at another company.
                                A working TV? How boring!

                                Comment

                                • senndogg
                                  Badcaps Veteran
                                  • Dec 2011
                                  • 383
                                  • Albania

                                  #17
                                  Re: What to do to NOT get popcorned chip.

                                  I use a very-static self made station where bottom heating is the key. The small caps under the chip will never drop as they are already glued to the board. Just pay attention to not move your desk accidentally. i use a 600W halogen and usually i dont need to flow more than 2-3 minutes for removing the original 35x35mm chip with lead-free solder balls, and do not flow at all to chips with leaded solder balls as they will desolder very easy.
                                  Unfortunately i havent had success with the big chips in the VGAs as 50x50, but
                                  nowadays they are not worthy swapping as they cost more than a decent VGA.

                                  I have found out that the notorious series of chips tend to popcorn most.

                                  Comment

                                  • ravi_1617
                                    YY Solutions
                                    • Jan 2012
                                    • 343
                                    • India

                                    #18
                                    Re: What to do to NOT get popcorned chip.

                                    go to this website www.bgamods.com

                                    Comment

                                    • xboxhaxorz
                                      Senior Member
                                      • Jan 2011
                                      • 196

                                      #19
                                      Re: What to do to NOT get popcorned chip.

                                      the bottom of this article points out popcorning http://www.thebgareworkmachine.com/r...e-development/

                                      Comment

                                      Related Topics

                                      Collapse

                                      • acedogblast
                                        Guide to transplant MEC1503 EC chip and EEPROM reprogamming for T14s gen 2 and X13 gen 2
                                        by acedogblast
                                        This is a guide that I am writing for helping others to replace their MEC1503 EC chip if it breaks (or to get around an inconvenient prompt to the BIOS). This forum has been extremely helpful to me so I would like to contribute to help others. I will tell you right now that this task is very difficult to do. You MUST have experience and tools to do precision micro-soldering, BGA reballing, trace repair, and general laptop repair skills.

                                        There are some specialty tools needed to do this task. The replacement MEC1503 chips can be acquired from Aliexpress. Do not buy the bare chips as...
                                        11-02-2024, 05:13 PM
                                      • BMCappelletti
                                        Asus Chromebox CN62 - wrong chip put on BIOS reader
                                        by BMCappelletti
                                        Long story short:
                                        - dad converted Asus Chromebox CN62 into Windows compatible, with mrchromebox BIOS, years and years ago
                                        - gave the computer to his son a couple years later
                                        - son now decided to revert it to Chrome OS, to sell it as original (re-writing BIOS with the backup one created by his dad)
                                        - too lazy to remove the board from the case, thought a voltage regulator was the BIOS chip (you know... it has 8 legs)
                                        (seems like the story was not that short)

                                        He used alligator clips to read the chip. No luck reading it. Removed chip and placed on a SOC-8...
                                        01-08-2025, 07:27 PM
                                      • Troystain
                                        Help EZP2023+ updated chip database for w25q256jveq?
                                        by Troystain
                                        Hello, anyone here have updated ezp2023+ chip database in .dat file format.

                                        I need to add w25q256jveq chip but I do not know what data should I type.

                                        I'm using the ezp chip dabase editor posted from here https://www.badcaps.net/forum/troubl...ro-programmers

                                        The currenty unit model that I am trying to detect is HP elitebook 640 g9 which is currently locked on admin bios....
                                        11-25-2024, 12:53 AM
                                      • inck243
                                        Acer e15-e5-576g-5762 bricked. Bios chip won't interface in AsProgrammer.
                                        by inck243
                                        Thanks for any help. The board version is DAZAARMB6E0 REV: E. The bios chip is winbond 25Q64JVSIQ1736. W25Q64JV is not available in AsProgrammer -- only BV CV FV or FW_1.8c. The chip won't interface with asProgrammer and a CH341A. When I have this chip on the board, the laptop will not post but when I plug it in to power, the blue LED lights up, also the orange when the battery is connected. When I push the power on button, keyboard backlight turns on and the fan starts briefely then turns off. But I can't do anything to program this bios chip so I bought another one.

                                        The BIOS...
                                        07-25-2024, 09:17 AM
                                      • thxd43
                                        Lenovo laptop does not turn on, what does this number mean in a BIOS chip?
                                        by thxd43
                                        Hello, first of all, excuse me, I am using the translator, English is not my native language.

                                        I have a Lenovo ideapad 330S - 14IKB laptop.



                                        The tablet did not recognize me when I connected it, so I checked the device manager and I realized that there were many with the exclamation mark, so one by one I began to update their drivers until the sign disappeared of admiration, I even updated the BIOS, and the laptop rebooted normally and worked, so far so good, but the tablet still did not recognize me, I read on the internet that it could be due to a...
                                        02-23-2023, 08:37 PM
                                      • Loading...
                                      • No more items.
                                      Working...