Re: BGA rework : IR or convection

We are currently looking at purchasing some BGA rework equipment. Could someone give us the pro's and cons of IR heating (top/bottom)vs. hot air convection ? All other tips are also welcome.

Thanks

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| We are currently looking at purchasing some BGA rework equipment. Could someone give us the pro's and cons of IR heating (top/bottom)vs. hot air convection ? | All other tips are also welcome. | | Thanks | Philip, I have been doing BGA rework for atleast three years. During those years I have used AIR-VAC, OK Industries, SRT and CONCEPTRONICS rework stations. All of these machines work for BGA rework, well some have beter options than others. The Conceptronics machine is the one that I have liked the most, for the reason that It has top/bottom convection and a IR heating pannel that pre-heats the board. It is PC controled and easy to use. I have used this machine to do re-balling, removal, placement on several types of BGA's including CSP's.

Hope this help a little.

If you like any other feedback please fill free to e-mail me or call me at (619) 642-5235.

Thanks

Tony A

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| We are currently looking at purchasing some BGA rework equipment. Could someone give us the pro's and cons of IR heating (top/bottom)vs. hot air convection ? | All other tips are also welcome. | | Thanks | Philip, My experience is primarily with Air-Vac, but I have some familiarity with other models. I personally think hot gas is the most reliable way to heat BGAs for rework. You will also require a suitable method for pre-heating of the board. This can be hot air or IR, but be sure it is capable for all sizes and thicknesses of boards that you will be handling. Check that the board holders and supports will accomodate all of your designs (large/small, thick/thin, single side/double side). Other considerations involve the design of the rework nozzles. Look at the amount of "keep-out" area that they require with respect to adjacent components. Consider the nozzle cost and delivery, and how many you will need. Be sure they are capable of providing the rework thermal profile that you require. You may also want to evaluate capability for CSP rework. These have some special requirements. Finally, you will want to look at capability for all types of BGAs and PCBs, not just the demo boards that you see at shows. I hope this helps you get started.

Glenn Robertson glenn.robertson@usa.alcatel.com

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| | We are currently looking at purchasing some BGA rework equipment. Could someone give us the pro's and cons of IR heating (top/bottom)vs. hot air convection ? | | All other tips are also welcome. | | | | Thanks | | | Philip, | I have been doing BGA rework for atleast three years. During those years I have used AIR-VAC, OK Industries, SRT and CONCEPTRONICS rework stations. All of these machines work for BGA rework, well some have beter options than others. The Conceptronics machine is the one that I have liked the most, for the reason that It has top/bottom convection and a IR heating pannel that pre-heats the board. It is PC controled and easy to use. I have used this machine to do re-balling, removal, placement on several types of BGA's including CSP's. | | Hope this help a little. | | If you like any other feedback please fill free to e-mail me or call me at (619) 642-5235. | | Thanks | | Tony A | Have any of you done work with CSP modules. Basically, a Chip Array or PBGA with passive components. We are having a tough time removing and replacing the parts without reflow the components inside the part. The passives are attached with a high lead solder (221 melt), but we are still seeing reflowing or internal shorts occurring after repair / replacement.

Any help or direction is appreciated,

Eric

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| | We are currently looking at purchasing some BGA rework equipment. Could someone give us the pro's and cons of IR heating (top/bottom)vs. hot air convection ? | | All other tips are also welcome. | | | | Thanks | | | Philip, | My experience is primarily with Air-Vac, but I have some familiarity with other models. I personally think hot gas is the most reliable way to heat BGAs for rework. You will also require a suitable method for pre-heating of the board. This can be hot air or IR, but be sure it is capable for all sizes and thicknesses of boards that you will be handling. Check that the board holders and supports will accomodate all of your designs (large/small, thick/thin, single side/double side). | Other considerations involve the design of the rework nozzles. Look at the amount of "keep-out" area that they require with respect to adjacent components. Consider the nozzle cost and delivery, and how many you will need. Be sure they are capable of providing the rework thermal profile that you require. | You may also want to evaluate capability for CSP rework. These have some special requirements. Finally, you will want to look at capability for all types of BGAs and PCBs, not just the demo boards that you see at shows. | I hope this helps you get started. | | Glenn Robertson | glenn.robertson@usa.alcatel.com | Glenn,

Thanks for the usefull info. You are talking about special considerations for CSP, could you be a bit more specific on what these considerations are?

Philip Bautil

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| | | We are currently looking at purchasing some BGA rework equipment. Could someone give us the pro's and cons of IR heating (top/bottom)vs. hot air convection ? | | | All other tips are also welcome. | | | | | | Thanks | | | | | Philip, | | I have been doing BGA rework for atleast three years. During those years I have used AIR-VAC, OK Industries, SRT and CONCEPTRONICS rework stations. All of these machines work for BGA rework, well some have beter options than others. The Conceptronics machine is the one that I have liked the most, for the reason that It has top/bottom convection and a IR heating pannel that pre-heats the board. It is PC controled and easy to use. I have used this machine to do re-balling, removal, placement on several types of BGA's including CSP's. | | | | Hope this help a little. | | | | If you like any other feedback please fill free to e-mail me or call me at (619) 642-5235. | | | | Thanks | | | | Tony A | | | Have any of you done work with CSP modules. Basically, a Chip Array or PBGA with passive components. We are having a tough time removing and replacing the parts without reflow the components inside the part. The passives are attached with a high lead solder (221 melt), but we are still seeing reflowing or internal shorts occurring after repair / replacement. | | Any help or direction is appreciated, | | Eric | Tony - I think most people would call this a Multi-Chip Module, although that term is no longer the "buzz-word" that it once was. What you are attempting is certainly a challenge. I don't know what repair equipment you are using, but I would certainly ask the supplier for any advice or help that they can provide. Also, be sure that the repair station is properly calibrated. I assume you part is a BGA (array) package, and that you have drilled holes in the mother board and installed thermocouples (.005" wire size) in some of the solder balls to establish your reflow profile. If that does not provide sufficient process information, there may be a way that you can place some thermocouples inside the package itself. You can get thermally conductive epoxy from Omega (and other sources) to hold them in place. In any case, be sure that all of the package solder balls are above reflow for enough time to make good metallurgical bonds to the pads. I have seen cases where a part was functional but failed a short time later for this reason. I hope this is helpful, and good luck in your work.

Glenn Robertson glenn.robertson@usa.alcatel.com

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| | | We are currently looking at purchasing some BGA rework equipment. Could someone give us the pro's and cons of IR heating (top/bottom)vs. hot air convection ? | | | All other tips are also welcome. | | | | | | Thanks | | | | | Philip, | | My experience is primarily with Air-Vac, but I have some familiarity with other models. I personally think hot gas is the most reliable way to heat BGAs for rework. You will also require a suitable method for pre-heating of the board. This can be hot air or IR, but be sure it is capable for all sizes and thicknesses of boards that you will be handling. Check that the board holders and supports will accomodate all of your designs (large/small, thick/thin, single side/double side). | | Other considerations involve the design of the rework nozzles. Look at the amount of "keep-out" area that they require with respect to adjacent components. Consider the nozzle cost and delivery, and how many you will need. Be sure they are capable of providing the rework thermal profile that you require. | | You may also want to evaluate capability for CSP rework. These have some special requirements. Finally, you will want to look at capability for all types of BGAs and PCBs, not just the demo boards that you see at shows. | | I hope this helps you get started. | | | | Glenn Robertson | | glenn.robertson@usa.alcatel.com | | | Glenn, | | Thanks for the usefull info. You are talking about special considerations for CSP, could you be a bit more specific on what these considerations are? | | Philip Bautil | Philip -

The primary requirement is the ablity to handle the smaller package sizes and align them properly for a pitch as low as 0.5mm. Many modules with CSPs will require very limited "keep-out" area, so you want to look for equipment that can accomodate that restriction. You may find it helpful to be able to watch the part as it is heated. You can actually observe the part drop slightly and sometimes align with the pads.

Glenn Robertson glenn.robertson@usa.alcatel.com

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