BGA, QFP and brothers

Hello, All Тема не новая, есть некоторая информация По BGA есть вот это: http://www.lrr.in.tum.de/~acher/bga/ на немецком, если будет спрос, я могу перевести. Второе, пролетало в comp.arch.fpga следующее: "Contrary to others experience, I've done BGA parts pretty successfully in "hobby mode", as well as with professional rework equipment. I've developed a few "tricks" that help. First, solder paste is very difficult to manage with hand placement. Instead, use water soluable flux on the board pads, and push a large solder ball over all the boards pads till you have a small shinny solder mound on each pad with a fairly uniform size to attach the BGA with. Clean the board well to remove the used flux, and apply fresh flux to both the board and the BGA balls. Second, position the BGA part on top of the pcb pads. It's very useful at this point to have a silk screened outline of the package to center the part with, that is very close to the real package size. Third, carefully place in a preheated convection oven, and bake. The correct time for this takes some practice and calibration of YOUR setup. Visually verify that the balls have a uniform "squat" on all four sides ... this generally means the parts wetted fine, and the part settled down on the balls at reflow temp. Read the lit about recommended profiles for various packages ... youmay not be able to exactly do those profiles, but you can come close with some practice. I've had pretty good luck using several different table top forced air "convection ovens" with digital controls. These are fairly inexpensive, and typically can regulate temps within 10 degrees F or so. Their problem, is uneven air flow which may result in uneven board heating if you do not give this some thought. Two of the ovens I used, required setting the board on a soda can near the center of the oven, with the turn table removed. A third oven required fashioning a foil air duct to make sure the hot air flow evenly covered the board. I suggest getting a non-contact IR thermometer with a spot capability including Harbor frieght. Using a salvage pcb of similar size and mass as your "test board" you can experiment with your "profile". I would suggest starting with the oven preheated to about 10-25F higher than your expected solder temp, quickly inserting your test board, and letting it bake for 2-3 minutes, open the door and quickly read several spots on the test board with the IR thermometer before the cool air drops the temp too much. Let the test board cool back to room temp, and repeat several times increasing the bake time about a minute each time. When you find the point where the board just reaches the solder temp, you can then program the oven to turn off 2 min after reaching that temp, and slowly cool the board back down without thermal shocking the BGA. Another process, is to pickup some slavage BGA parts with a similar package, and make a test board with the on die thermal diode brought out to test points, so you can run the wires out the door and monitor the die temp as you develop your thermal profile. You can also do this with your own board and FPGA's. You can also epoxy attach several thermal diodes to a test board, and monitor the profile in real time at several points. Pickup some Solderquik reballing preforms for the parts you plan to use. That way you can clean off your mistakes, and reball the parts to try again. The one thing you do not want to do, is get the newer BGA's too hot, or thermal shock them with cold air. Older parts in BG432 and BG560 packages are much more forgiving. I would suggest learning this process with XC4K, Virtex, or Virtex-E parts in BG432/BG560 packages, and once mastered move on to newer high density packages." Это тут за меня переведут :) И третье, что касается SMD воощбе, есть видеофайл (к сожалению текстовые комменты там на немецком, но их мало, как в немом кино прямо), где показано, как шаг за шагом припаять SMD деталь, т.е. xQFP. Интерес по первому и по третьему пунтку есть. Видео кстати взял вот отсюда:http://www.ulrichradig.de/gfx/video/SMD_einloeten.wmv

Hello, Jukov TQFP? soldering iron with microwave attachment & good flux: v2_finge:

Hello icebear Can you tell me in a nutshell what the foreigner is talking about?

Hello Orionsoft Ori> good flux In order to solder BGA it is more important to use a good non-boiling flux which for the most part compensates for the crookedness (shaking due to lack of drinking) of the hands Far away there was no photograph of a man whose balls stuck together and especially when he restores them :)

Hello, Jukov Juk> Can you tell me in a nutshell what the foreigner is talking about? Which of the three? The latter doesn't say that at all. I didn't read the first one completely. no photos, looks like what a hell of a machine he built himself for the BGA. There's no second I read it, just a trailer (literally a day or two ago there was this post in com.arch.fpga).

Hello hero her> In order to solder BGA, it is most important to use a good non-boiling flux her> which mostly compensates for crookedness (jitter with her> under-thrust) hands her> her> Far away there was no photograph of a man whose balls stuck together and her> especially when he restores them :) But still - really yourself? And then you are greeted with exclamations of “like two bytes...”, and on the other hand there is a complete counterweight (I wasn’t going to solder the BGA, just curious).

Hello icebear ice> But still, is it really possible to do it yourself? And then you are greeted with exclamations of “like two ice> bytes...", and on the other side there is a complete counterweight (I wasn’t going to solder ice> BGA, just interesting). In total, I have already soldered more than 1 thousand BGA microchips and I don’t think twice about it anymore. real or not. I looked at the unit; it’s easier to buy a soldering iron for $80 with a painting tool with a hairdryer it’s more difficult to blow away small parts :) Then you assemble the Legos and have fun until loss of pulse. Although I saw a device from a women's hair dryer that was over-chemicalized who removed/installed BGA without any problems

Hello Ronin Ron> making a signet is the main problem Under BGA? At home, yes :(

Hello hero making a signet is the main problem