* Posts: 61Getting started with BGA

*
Posts: 61

Getting started with BGA reflow and reballing ...
« on: June 28, 2014, 09:59:46 PM »
I have an Aoyue Int2703A+ soldering station combined with the Aoyue Int883 pre-heater and I want to reflow and reball the GPU chip on a laptop motherboard. I have read a few guides but there are still some questions that are still unresolved before I continue. I'm new to this and I've never done this before.

Quesion 1: What is recommended pre-heater temperature? The melting point of leaded solder is around 180°C and lead-free about 200°C, if I understand it correctly. How can I tell what alloy has been used? The laptop is an Asus, the motherboard was manufactured in 2007, most likely by Foxconn as that brand is mentioned on the motherboard. It has no RoHS or other markings that I can see that could potentially indicate that a lead-free soldering process has been used in the manufacturing.

Question 2: When I put the motherboard on the pre-heater, there are components on the back-side (facing the heating elements of the pre-heater), won't the solder melt and make these components fall off the PCB? Or will the surface-tension of the melted solder keep them in place anyway? Is there any measure I can take to prevent components from falling off the PCB?

Question 3: Can I put the entire motherboard as it is on the pre-heater or should I use some metal shroud that shields all parts of the motherboard but the surface underneath the GPU? Maybe that can damage the pre-heater? I suppose I could take a few layers of household aluminium foil and cut a square in it...

Question 4: Is there a risk that the motherboard will bend because of the heat or is it designed to take the heat? Maybe I should make some kind of pcb jig or fixture that prevents the motherboard from carrying its own weight so it won't bend when the heat softens it? I'm hoping that this won't be necessary. The jig that comes with the pre-heater will only hold the motherboard on its edges.

Question 5: Are all components designed to take the heat? I.e. the plastic sockets and connectors, won't they melt from the heat? The caps, isn't there a risk that they will pop? Strangely enough I cannot see any electrolytic caps on the motherboard so perhaps this is not an issue, but what applies in the more general case?
« Last Edit: June 29, 2014, 06:08:25 AM by axero »
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Offline wraper

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Posts: 1992
Country: lv

Re: Getting started with BGA reflow and reballing ...
« Reply #1 on: June 28, 2014, 10:27:01 PM »
No way you can reflow big BGAs with this equipment with acceptable rate of success. You will get 1 working board out of 4 at best. Other will be irreversibly dead (lifted pads, popped PCB) if you will succeed to remove IC at all. Moreover Nvidia BGAs don't handle even smallest overheat, they will pop. Also reball is a hoax in most cases because problem usually hides inside the IC itself (lost connection between die and substrate) and heating just revives it temporarily. Usually 1 week - couple of months. Also need to mention, most nvidia GPUs on ebay, aliexpress and other places made before 2009 are pure crap. They are just dead IC's removed from motherboards but they will work for a short time as described before. Also there are bunch of remarked chips sold. They might be IC's with different memory bus (will work in many cases but with ram divided by 2 for example). May be lower/higher end variation of the same chip, desktop GPU sold as notebook or even more exotic variants.
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Offline axero

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Posts: 61

Re: Getting started with BGA reflow and reballing ...
« Reply #2 on: June 28, 2014, 11:19:16 PM »
So what equipment do you propose to be used then? What temperatures are these GPU chips designed to take? They must be able to take something, otherwise they wouldn't survive manufacturing. And I read a lot of success stories on the tube of fixed Xboxess, Playstations and all sorts of remorseless pieces of laptop motherboards...

So I feel like you are exaggerating quite a bit here, I have soldered a lot of things but I have rarely experienced e.g. lifted pads. Still waiting for answers to my questions :(
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Offline wraper

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Posts: 1992
Country: lv

Re: Getting started with BGA reflow and reballing ...
« Reply #3 on: June 28, 2014, 11:54:06 PM »
Problem with such hot air stations is that you can't evenly heat up large area, therefore while you are burning one area, solder is not yet melted in another. Trust me, soldering BGA is completely different from soldering SMT resistor or QFN IC. Board warping also is a serious problem, that's why big preaheaters are needed.There are large IR or hot air stations with big preheaters and tight temperature control for this. For example:
http://www.ebay.com/itm/Newest-BGA-ACHI-IR-12000-Dark-Infrared-Rework-BGA-Station-for-Reworking-BGA-/181281761347?pt=LH_DefaultDomain_0&hash=item2a353c2843
http://www.ebay.com/itm/Jovy-RE-8500-Infrared-BGA-Rework-Station-for-SMD-BGA-Reflow-Rework-/151320432090?pt=LH_DefaultDomain_0&hash=item233b668dda But I can't call them super duper stations. They are in budget range, so not perfect at all. I would say that they are cheapest you can buy to get acceptable results when soldering large BGA's. There are cheaper ones with halogen heat lamp but they are total crap.
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Offline axero

Regular Contributor
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Posts: 61

Re: Getting started with BGA reflow and reballing ...
« Reply #4 on: June 29, 2014, 01:09:21 AM »
The Int 883 is big enough to heat an entire full ATX motherboard so I don't think size and power is an issue here. The heating elements of the pre-heater looks pretty good too and they are probably quite capable of distributing the heat evenly. Here's an overview of the 883 and its smaller sibling 863:

http://bit.ly/VvTTWt

I realize now that the jig can be configured to secure the motherboard so that it won't warp. I bought this unit from a reputable seller that sells equipment that costs more than 6 times as much as the ebay items you linked to.

Perhaps there may be an issue with the hot air gun of the re-work station. Perhaps these questions better be asked at bga rework forums, as I seem to get no answer here...
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Offline wraper

Super Contributor
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Posts: 1992
Country: lv

Re: Getting started with BGA reflow and reballing ...
« Reply #5 on: June 29, 2014, 01:52:50 AM »
Obviously BGA forum would be better place. What I can almost guarantee that you will get dead board if you have not couple of scrap boards to try on them first.
Answers:
Solder is lead free. Parts won't fall off (except big parts with very small footprints) unless you'll shake the board. You must cover plastic connectors nearby. All board must be heated evenly underneath. If this is Nvidia GPU made in 2007 then just either heat that chip and it will work some more time or you need to get replacement with 2009+ date code (with all problems getting proper one, I wrote about). Name the chip model BTW as some are no way you can get normal replacement. As BGA is almost certainly glued to the board on the sides (must remove most of the glue on board preheated to 110-140oC), you will be unable to catch solder melt moment without controlling the temperature (lifted pads I warned about). That jig is no good, as it will move parts underneath when solder melts, there must be no any objects under the GPU and nearby.
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Offline axero

Regular Contributor
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Posts: 61

Re: Getting started with BGA reflow and reballing ...
« Reply #6 on: June 29, 2014, 06:07:26 AM »
Ok, but during the reflow process I guess that the pre-heater should bring the temperature up to at least 180°C. Then the top heater should bring it up to at least 220°C for a few minutes during the peak of the reflow process. The pre-heater is programmed to bring the temperature up and down slowly and "soak" the PCB it as they call it.

The BGA chip is not that big, it's only 32 by 32 mm and there is a 30 by 30 mm nozzle for the heater gun so the heating will be pretty evenly distributed over the chip on the top side as well.

The GPU chip is an nVidia G84-625-A2 sharing the heat-sink with an Intel SLA5U chip. It is a GeForce 9500M GS and it has its own dedicated RAM, i.e. it isn't sharing RAM with the system. The enclosed picture shows these two chips. As can be seen in the picture, it looks like the chips are glued to the PCB in the corners.

The system boots normally and I can log in to windows 7 as usual but the screen is black and there is no image output from any of the three ports (LCD 30-pin, VGA out, HDMI out). No BIOS, no ASUS greetings logo, no MS-DOS prompt, no Windows, nothing, the screen is black the entire time.

* GPUandSBchips.jpg (755.69 kB, 1456x1908 - viewed 348 times.)
« Last Edit: June 29, 2014, 06:14:23 AM by axero »
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Offline wraper

Super Contributor
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Posts: 1992
Country: lv

Re: Getting started with BGA reflow and reballing ...
« Reply #7 on: June 29, 2014, 06:46:09 AM »
You can heat up GPU a bit, for example to 120-150o C with hot air and try if MB works. If it works ok, 100% GPU fail. So you either need to heat it to higher temperature to prolong it's life to couple of months or if you are very lucky maybe even year. Or change it, no reball, as it is useless and only stressing PCB. Actually it is not so small and it may be difficult to successfully change it and will require higher preheat than with normal equipment. You must try on something else first (at least removing the chip) or you will get a dead board with 95% probability. Verified by a lot of people including myself. Also small thermocouple near to the BGA would be very helpful. Most of the G84-625-A2 sold from China and other places proven to be remarked in most cases, from something that usually won't work. On Russian notebook repair forums repair guys suggest to change it to G84

ผลลัพธ์ (ไทย) 1:

* Posts: 61Getting started with BGA reflow and reballing ...« on: June 28, 2014, 09:59:46 PM »I have an Aoyue Int2703A+ soldering station combined with the Aoyue Int883 pre-heater and I want to reflow and reball the GPU chip on a laptop motherboard. I have read a few guides but there are still some questions that are still unresolved before I continue. I'm new to this and I've never done this before.Quesion 1: What is recommended pre-heater temperature? The melting point of leaded solder is around 180°C and lead-free about 200°C, if I understand it correctly. How can I tell what alloy has been used? The laptop is an Asus, the motherboard was manufactured in 2007, most likely by Foxconn as that brand is mentioned on the motherboard. It has no RoHS or other markings that I can see that could potentially indicate that a lead-free soldering process has been used in the manufacturing.Question 2: When I put the motherboard on the pre-heater, there are components on the back-side (facing the heating elements of the pre-heater), won't the solder melt and make these components fall off the PCB? Or will the surface-tension of the melted solder keep them in place anyway? Is there any measure I can take to prevent components from falling off the PCB?Question 3: Can I put the entire motherboard as it is on the pre-heater or should I use some metal shroud that shields all parts of the motherboard but the surface underneath the GPU? Maybe that can damage the pre-heater? I suppose I could take a few layers of household aluminium foil and cut a square in it...Question 4: Is there a risk that the motherboard will bend because of the heat or is it designed to take the heat? Maybe I should make some kind of pcb jig or fixture that prevents the motherboard from carrying its own weight so it won't bend when the heat softens it? I'm hoping that this won't be necessary. The jig that comes with the pre-heater will only hold the motherboard on its edges.Question 5: Are all components designed to take the heat? I.e. the plastic sockets and connectors, won't they melt from the heat? The caps, isn't there a risk that they will pop? Strangely enough I cannot see any electrolytic caps on the motherboard so perhaps this is not an issue, but what applies in the more general case?« Last Edit: June 29, 2014, 06:08:25 AM by axero »LoggedOffline wraper Super Contributor *** Posts: 1992 Country: lvRe: Getting started with BGA reflow and reballing ...« Reply #1 on: June 28, 2014, 10:27:01 PM »No way you can reflow big BGAs with this equipment with acceptable rate of success. You will get 1 working board out of 4 at best. Other will be irreversibly dead (lifted pads, popped PCB) if you will succeed to remove IC at all. Moreover Nvidia BGAs don't handle even smallest overheat, they will pop. Also reball is a hoax in most cases because problem usually hides inside the IC itself (lost connection between die and substrate) and heating just revives it temporarily. Usually 1 week - couple of months. Also need to mention, most nvidia GPUs on ebay, aliexpress and other places made before 2009 are pure crap. They are just dead IC's removed from motherboards but they will work for a short time as described before. Also there are bunch of remarked chips sold. They might be IC's with different memory bus (will work in many cases but with ram divided by 2 for example). May be lower/higher end variation of the same chip, desktop GPU sold as notebook or even more exotic variants.LoggedOffline axero Regular Contributor * Posts: 61Re: Getting started with BGA reflow and reballing ...« Reply #2 on: June 28, 2014, 11:19:16 PM »So what equipment do you propose to be used then? What temperatures are these GPU chips designed to take? They must be able to take something, otherwise they wouldn't survive manufacturing. And I read a lot of success stories on the tube of fixed Xboxess, Playstations and all sorts of remorseless pieces of laptop motherboards...So I feel like you are exaggerating quite a bit here, I have soldered a lot of things but I have rarely experienced e.g. lifted pads. Still waiting for answers to my questions :(LoggedOffline wraper Super Contributor *** Posts: 1992 Country: lvRe: Getting started with BGA reflow and reballing ...« Reply #3 on: June 28, 2014, 11:54:06 PM »Problem with such hot air stations is that you can't evenly heat up large area, therefore while you are burning one area, solder is not yet melted in another. Trust me, soldering BGA is completely different from soldering SMT resistor or QFN IC. Board warping also is a serious problem, that's why big preaheaters are needed.There are large IR or hot air stations with big preheaters and tight temperature control for this. For example:http://www.ebay.com/itm/Newest-BGA-ACHI-IR-12000-Dark-Infrared-Rework-BGA-Station-for-Reworking-BGA-/181281761347?pt=LH_DefaultDomain_0&hash=item2a353c2843http://www.ebay.com/itm/Jovy-RE-8500-Infrared-BGA-Rework-Station-for-SMD-BGA-Reflow-Rework-/151320432090?pt=LH_DefaultDomain_0&hash=item233b668dda But I can't call them super duper stations. They are in budget range, so not perfect at all. I would say that they are cheapest you can buy to get acceptable results when soldering large BGA's. There are cheaper ones with halogen heat lamp but they are total crap.LoggedOffline axero Regular Contributor * Posts: 61Re: Getting started with BGA reflow and reballing ...«ตอบกลับ #4 ใน: 29 มิถุนายน 2014, 01:09:21 AM »Int 883 มีขนาดใหญ่พอที่จะความร้อนมีทั้งเมนบอร์ด ATX เต็มดังนั้นฉันไม่คิดว่า ขนาด และพลังงานเป็นปัญหาที่นี่ องค์ประกอบความร้อนของฮีตเตอร์ก่อนลักษณะสวยดีเกินไป และพวกเขาจะค่อนข้างคงที่สามารถกระจายความร้อนอย่างสม่ำเสมอ นี่คือภาพ 883 และพี่น้องเล็กของ 863:http://bit.ly/VvTTWtฉันรู้ที่ฉลุสามารถกำหนดค่าความปลอดภัยแผงวงจรหลักเพื่อให้มันไม่เส้นยืน ฉันซื้อนี้หน่วยจากผู้ขายมีชื่อเสียงที่ขายอุปกรณ์ที่ต้นทุนมากกว่า 6 ครั้งเท่ากับสินค้า ebay ที่คุณเชื่อมโยงกับบางทีอาจมีปัญหากับปืนลมร้อนของสถานีทำงานใหม่ บางทีคำถามเหล่านี้ดีถูกถามที่กระดานข่าวสาหร่ายทำใหม่ เป็นฉันดูเหมือนจะได้รับการตอบรับที่นี่...เข้าสู่ระบบWraper ออฟไลน์ ผู้สนับสนุนซุปเปอร์ *** บทความ: 1992 ประเทศ: lvRe: การเริ่มต้นกับสาหร่าย reflow และ reballing ...«ตอบกลับ #5 บน: 29 มิถุนายน 2014, 01:52:50 AM »แน่นอนสาหร่ายฟอรั่มจะดีกว่า อะไรสามารถเกือบรับประกันว่า คุณจะได้รับบอร์ดตายว่าไม่คู่ของบอร์ดเสียจะลองพวกเขาก่อนคำตอบ:Solder is lead free. Parts won't fall off (except big parts with very small footprints) unless you'll shake the board. You must cover plastic connectors nearby. All board must be heated evenly underneath. If this is Nvidia GPU made in 2007 then just either heat that chip and it will work some more time or you need to get replacement with 2009+ date code (with all problems getting proper one, I wrote about). Name the chip model BTW as some are no way you can get normal replacement. As BGA is almost certainly glued to the board on the sides (must remove most of the glue on board preheated to 110-140oC), you will be unable to catch solder melt moment without controlling the temperature (lifted pads I warned about). That jig is no good, as it will move parts underneath when solder melts, there must be no any objects under the GPU and nearby.LoggedOffline axero Regular Contributor * Posts: 61Re: Getting started with BGA reflow and reballing ...« Reply #6 on: June 29, 2014, 06:07:26 AM »Ok, but during the reflow process I guess that the pre-heater should bring the temperature up to at least 180°C. Then the top heater should bring it up to at least 220°C for a few minutes during the peak of the reflow process. The pre-heater is programmed to bring the temperature up and down slowly and "soak" the PCB it as they call it.The BGA chip is not that big, it's only 32 by 32 mm and there is a 30 by 30 mm nozzle for the heater gun so the heating will be pretty evenly distributed over the chip on the top side as well.The GPU chip is an nVidia G84-625-A2 sharing the heat-sink with an Intel SLA5U chip. It is a GeForce 9500M GS and it has its own dedicated RAM, i.e. it isn't sharing RAM with the system. The enclosed picture shows these two chips. As can be seen in the picture, it looks like the chips are glued to the PCB in the corners.The system boots normally and I can log in to windows 7 as usual but the screen is black and there is no image output from any of the three ports (LCD 30-pin, VGA out, HDMI out). No BIOS, no ASUS greetings logo, no MS-DOS prompt, no Windows, nothing, the screen is black the entire time.* GPUandSBchips.jpg (755.69 kB, 1456x1908 - viewed 348 times.)« Last Edit: June 29, 2014, 06:14:23 AM by axero »LoggedOffline wraper Super Contributor *** Posts: 1992 Country: lvRe: Getting started with BGA reflow and reballing ...« Reply #7 on: June 29, 2014, 06:46:09 AM »You can heat up GPU a bit, for example to 120-150o C with hot air and try if MB works. If it works ok, 100% GPU fail. So you either need to heat it to higher temperature to prolong it's life to couple of months or if you are very lucky maybe even year. Or change it, no reball, as it is useless and only stressing PCB. Actually it is not so small and it may be difficult to successfully change it and will require higher preheat than with normal equipment. You must try on something else first (at least removing the chip) or you will get a dead board with 95% probability. Verified by a lot of people including myself. Also small thermocouple near to the BGA would be very helpful. Most of the G84-625-A2 sold from China and other places proven to be remarked in most cases, from something that usually won't work. On Russian notebook repair forums repair guys suggest to change it to G84

ผลลัพธ์ (ไทย) 3:

กระทู้ : 61


เริ่มต้นกับ BGA reflow reballing และ . . . . . . .
«เมื่อ : มิถุนายน 28 , 2014 , 09:59:46 PM »
ฉันมี aoyue int2703a บัดกรีสถานีรวมกับเครื่อง aoyue int883 ก่อนและฉันต้องการ reflow reball GPU และชิปบนเมนบอร์ดแล็ปท็อป . ฉันได้อ่านไม่กี่แนว แต่ยังคงมีคำถามที่ยังค้างคาอยู่ ก่อนที่จะต่อฉันใหม่นี้ และผมไม่เคยทำแบบนี้มาก่อน . . .

quesion 1 : แนะนําอะไรก่อนอุณหภูมิฮีตเตอร์ จุดหลอมเหลวของตะกั่วบัดกรีประมาณ 180 ° C และตะกั่วประมาณ 200 องศา C ถ้าผมเข้าใจมันได้อย่างถูกต้อง ฉันสามารถบอกได้ว่าแม็กซ์ถูกใช้ ? แล็ปท็อปเป็น ASUS , เมนบอร์ดที่ถูกผลิตในปี 2550 ส่วนใหญ่โดย Foxconn เป็นแบรนด์นั้นเป็นที่กล่าวถึงบนเมนบอร์ดมันไม่มีภาพ หรือเครื่องหมายอื่นที่ฉันสามารถดูที่อาจบ่งชี้ว่า ปราศจากสารตะกั่วบัดกรีกระบวนการได้ถูกใช้ในการผลิต

คำถามข้อที่ 2 : เมื่อฉันใส่เมนบอร์ดในเครื่องก่อน มีองค์ประกอบในด้านหลัง ( ซึ่งองค์ประกอบความร้อนของเครื่องทำน้ำอุ่นก่อน ) ไม่บัดกรี ละลายและให้ส่วนประกอบเหล่านี้ตก PCB ?หรือจะแรงตึงผิวของหลอมประสานให้พวกเขาในสถานที่ต่อไป มีมาตรการใด ๆที่ฉันสามารถใช้เพื่อป้องกันไม่ให้ชิ้นส่วนตกลงมา PCB ? คำถามที่ 3 :

ผมจะใส่เมนบอร์ดทั้งหมดเป็นเครื่องก่อน หรือผมควรใช้โลหะห่อหุ้มที่เกราะทุกส่วนของเมนบอร์ด แต่พื้นผิวใต้ GPU ? บางทีมันอาจจะสร้างความเสียหายให้อุ่นก่อน ?ฉันคิดว่าฉันอาจจะต้องใช้เวลาในชั้นของอลูมิเนียมฟอยล์และตัดเป็นสี่เหลี่ยมในมัน . . . . . . .

คำถาม 4 : มีความเสี่ยงที่เมนบอร์ดจะโค้งเพราะความร้อน หรือมันออกแบบมาเพื่อใช้ความร้อน ? บางทีฉันอาจจะทำให้บางชนิดของการ หรือโคมที่ป้องกันเมนบอร์ดจากการแบกน้ำหนักของตัวเองดังนั้นมันจะไม่โค้งงอเมื่อความร้อนนุ่ม ?ฉันหวังว่า นี้ไม่จำเป็น จิ๊กที่มากับเครื่องก่อนจะถือเมนบอร์ดบนขอบ

คำถามที่ 5 : มีทุกองค์ประกอบที่ออกแบบมาเพื่อใช้ความร้อน ? เช่น ฐานพลาสติก และเชื่อมต่อพวกเขาจะไม่ละลายจากความร้อน ? หมวก , ไม่มีความเสี่ยงที่พวกเขาจะปรากฏ ?