Reflowing with Thermo Couples(Reflowprofiles incl)

This is the recommended reflow profile for a setup with a BGA rework station a preheater and thermo couples.

Note the temp readings are from the thermo couples on top of the board you are meant to place them with kapton tape close to the chip you are going to reflow so that it touches the mainboard fiber.

Material list:

Thermo Couples and Thermometer:

K-type Thermo couples and a Thermometer you can get from our Shop, this one has got a good sensitivity, we found the ones on Ebay with 2 probes are very unreliable and have delays:

http://xbox-experts.com/stores_shop.php

To keep the thermo couples in place use Kapton or aluminum tape(kapton is better though because it really insulates the fiber of the probes too, you can get the tape from our shop too at a cheap price).

Here is a graphic bigwerm made which illustrates where to position the thermal probes, Thanks:

heres a crud pic i made in paint,the grey strip is high heat aluminum tape which you cover just the very tip(ball) the gold is the kapton tape.the k type thermal couple end will be very similar to the image in the pic.the tip of the probes are about "1mm" from the gpu.

Preheater:

In terms of preheaters Presto griddles are very popular and they give pretty good results at a price of about 30$US or just a simple hot plate, in Europe searchin for a "Teppan yaki grill" often works better because Presto isnt as widely spread.

Besides that the 853-A IR-preheater by AOYUE is also quite popular, can be gotten at ownta.com for example for about 103€, they ship worldwide at decent prices and there are also lots of other more advanced preheaters to choose from, or for the U.S sra-solder.com for about 105 $US, they also ship worldwide but usually it is quite expensive.

I don't recommend the Aoyue preheater because it is too small to provide sufficient heat for a 360 motherboard or larger board. -pure3d2

BGA Rework station:

There are also several to choose from but most prefer the AOYUE 968, the 852 A+ is also quite popular, besides that there are also still less pricey ones by KADA and others, your best go will be for one of the AOYUE ones though.

You can either look on Ebay, or get them from sra-solder.com (North America) or ownta.com (Rest of the World)

These Rework stations must sometimes be recalibrated though, the heating element must often be adjusted, how this is done for the AOYUE ones is shown nicely here:
http://forums.xbox-experts.com/viewtopic.php?f=6&t=1397 (Kudos to Deary for that tutorial, thanks)

For KADA stations yaywoop made a tutorial which you can find here:
http://forums.xbox-experts.com/viewtopic.php?f=8&t=1102

Hotair Gun Nozzles, which ones do you need?

For GPU and CPU you will need the 4141, that makes up to 40x40mm space, the chips dimensions might only be 35x35mm but you always need a little space still around.

For HANA and Southbridge chip the 2828 nozzles are fine.

For the RAM chips the 1919 is fine, it already comes with many rework stations though so you will probably not have to buy it.

In general nozzles with a NET are to be preferred because they offer a much better and more even airflow thereby leading to better reflow results apparently, so you might want to spend the dollars extra for one of them.

You can get nozzles here: sra-solder.com (North America) and ownta.com (Rest of the World)

Flux usage:

The usage of flux which type and kind always leads to a lot of controversy, some prefer liquid flux, others paste, some make their own.

Some of the things to take care of in general are though, that the flux you are using is a no-clean type(must not be removed after application) and it should be non-corrosive.

To apply flux use a pipette to suck up some of the flux, then hold the mainboard at an angle and gently flush flux under the chip from the one side until you see it leaking out on the other side, repeat that for all 4 sides of the chip to assure all solder balls are covered, use q-tips to get rid of the flux around the chip that leaked out, it will turn all black and sticky after the reflow + the tape from the thermo couple can get lose from the stuff so make sure to clean it up properly.
Q-tips + some alcohol do the trick, if it is a pretty old board you might also want to flush alcohol under the chip prior to applying flux to wash out dirt etc which can effect the reflow too.

Flux always got an activation time you find it in the datasheets, but usually it is preheating the board for about 5-10 minutes before starting the actual reflow. This is important to give the liquid components, like alcohol or water enough time to evaporate so that the solder balls are only covered in a layer of the flux particles etc, if you dont wait long enough this can cause the popcorn effect because all the alcohol would evaporate when the solder is already vulnerable.

Where to get flux?

For North America just look on ebay you find lots there: Ebay.com (Search for "no clean liquid flux")

For Europe Distrilec.com seems to be a reliable place they also offer a large variety on Ebay you dont find as much often.

Reballing:

For Reballing you will first need a lot of reflowing experience so if you are new you should not be investing in it yet. In general you can expect your first reflows to mess up thats just normal you must get used to the equipment and perfect your profile with temps and timings and the combination of preheater and hot air. This slightly differs for every setup.
Best is to get a couple of consoles from Ebay to test out your setup so that you dont mangle customers consoles.

Once you have perfected reflowing and got the timings right you can attempt to take off chips without damaging pads, for that slightly higher temps are needed because you will have to raise the nozzle, same accounts for this expect to mess up some consoles in the learning process. To take off the chip most stations already come with a vacuum pen otherwise get one for 4 $US.

This is however dedicated to reflowing for now, so that just as a side note....

Baking and flattening out the the mainboard before reflowing

Before reflowing you might want to perform a low-temp oven bake of the board, temperatures under 70C for several hours. This gets rid of moisture and flattens the board out as a whole.
This is especially recommended if a weird x-clamp fix or the x-clamps caused visible warping because this can lead to a failed reflow, corners of the chip might lift etc and you might end up with 0002 or 0003, also by experience board which were baked prior to reflowing last a lot longer because the solder balls are not moist and so less vulnerable.

Here you can find the oven baking tutorial, many repair shops get big regular kitchen ovens and bake 5 and more boards at once in it so this is a general idea you might want to invest in too.

http://xbox-experts.com/tutorial/oven-bake/

The actual Reflow and Recommended Profiles

(Kudos to pure3d2 for this reflow profile)

Once the preheater warms the board until the topside thermocouple reads 125-130C, I wait 5 minutes. Then I turn on the station at 150C and hold for 1 minute, then 200C, hold for 1 minute, then 250C hold for 25-30 seconds.

After this, I go up 20C every 8-10 seconds until the thermocouple reading shows 215C (for Xenon boards and some Zephyr boards) hold for 10-15 seconds, drop station down to 200C, then down to 100C as fast as it can go, turn off griddle, turn off station.

For some Zephyr, all Falcon and Jasper boards, I continue to add 20C every 8-10 seconds until the thermocouple reading shows 220-225C, hold for 10-15 seconds, drop station down to 200C, then down to 100C as fast as it will go, turn off griddle, turn off station.

The key is using a thermocouple. Some boards are thicker than others so it takes more heat/time to get to the reflow temperature.

Here is another reflow profile posted by xboxhaxorz: http://xbox-experts.com/tutorial/reflow-tutorial-with-equipment-list/

For help and questions check out this thread on the forums: http://forums.xbox-experts.com/viewtopic.php?f=8&t=3074 or just join the live chat

Just thought a summary of that information was needed at a point, credits go to many users on the forums who contributed to it as a whole, thank you to all of you.

For suggestions, possible additions and general feedback please send me an Email to: wilhelm@xbox-experts.com