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 Nov 29, 2006 |
BGA ball crack at pad/solder ball interface Dear all, Recently, we run 2 models with heat sink attachment on top of this BGA(on top of this BGA, there is flip chip attached at the center of the BGA). Hence, the center of the BGA is higher than corner/side. We used conventional way to attach heat sink to the BGA. Heat sink anchor pullout is a retention spring that press across the BGA package top surface and locks on both sides at the 2 hooks soldered to the board next to the edge of the BGA ...
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Jul 21, 2006 |
... Test Faulure due to BGA ICs Does replacing the BGA fix the problem? To be a little more blunt, is the BGA or is it the tech says it's the BGA. Beleive none of what you hear and only half of what you see. What kind of BGA is it? If it is one of those BGA's with a built in heatsink, then the center balls may not be getting complete reflow. If it is a BGA with a flange, maybe the cool down is too fast and the BGA is warped during cool down. If you can sacrifice a PCB and BGA for profiling that ...
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Aug 17, 1998 |
... the surface should be allowed to cool for a couple of minutes. Re Balling BGA Devices To replace solder balls on to a BGA first all the uneven solder or solder balls should be removed using a conventional de soldering tool. When the surface of all the pads is flat either solder paste may be applied to the part, a liquid flux dispensed or flux paste stencil printed on to the BGA. A clean stencil is then placed on to the BGA and solder balls placed in the stencil. The over sized apertures allow ...
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Apr 13, 2004 |
... Soluble for No Clean BGA Balls Hi DaveF, To explain. The BGA that we have is from Motorola. The solder balls of these BGA's are Eutectic Solder and processed using a NC flux (as per info from supplier). So this means that the BGA pad and solder connections had NC flux process. We are applying WS paste on our PCB's then place the BGA's from Motorola with a NC processes bonding between the ball and bga pad. Though we are getting good solder joint and drop on our BGA's after reflow soldering, I'm ...
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Jan 15, 1999 |
Re-Balling BGA and BGA sockets Does anyone have information pertaining to re-balling BGA components using balls that are preformed onto disolable paper waffers (mini BGA reballing kit)? The paper containing the specific BGA device/pattern would be placed onto the BGA then processed through a reflow (oven). After reflow, the BGA is placed in water and the paper containing the balls is pulled away from the component, resulting in a reballed BGA. Is this product available on the market or is it a ...
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Aug 18, 1999 |
Bridge on BGA Yesterday as I was creating a profile on a plastic BGA using Conceptronics freedom 2000 rework station, I happend to discover that I was able to remove solder bridging from a plastic BGA. This is what I did. Created a removal profile, I had a board that had 3 bridges on the BGA. Run the profile and as soon as saw the BGA that was ready for removal, I brought down the nossle Picked up the BGA and came up almost 20mils than dropped back the BGA. I X-Ray the BGA, no bridging. The ...
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Mar 14, 2007 |
... Package BGA Components any issue in SMT? Hi Muhammad thanks for the reply. However, this is my current situation. We are currently using some BGA's with this kind of packaging BGA over BGA. I have verified solderability of the main BGA (below Bga the one w/c will be soldered to PCB) using Ersascope inspection, X-ray inspection rotated 90 degree and also profile data's all is fine. However, during testing our ICT encounter's testing failures they simple use hot air to blow-up the BGA and retest ...
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Dec 7, 2006 |
BGA rework with unplugged vias PCB As you are aware the common method to rework BGA is : 1. Remove BGA with hot air reflow machine ( SRT as current practice) 2. Clean the BGA pad using solder iron and solder wick. 3. Replace BGA with SRT rework machine. The problem we have with unplug via is when we clean the BGA pad, the solder resist cover the trace between pads and vias will be removed. During the solder removal process certain amount of solder will also get into the unplug vias as well ...
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Jul 22, 1999 |
Bga reballing Does anyone have any experiences with bga reballing. When I had reworked failed bga part with new part It was good. So I tried to reball bga detached but failed . I guess the cause of fail is thermal shock. IS IT OK TO REBALL BGA PARTS DETACHED ? I wonder. Before an experiment I'm sured that bga parts can stand thermal shock.The result was different as I expected THE PROCESS I DID IS AS BELOW �� Detach an bga part failed with bga rework machine�� add heat �� Remove ...
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Mar 26, 2010 |
BGA Placement Process Thank you Graham for the response. The particular BGA that we currently Bake is a Level 3 BGA, which means the BGA will expire in 7 days after removal. We are currently baking the BGAs once a week for the problem described above. These devices are under constant use and therefore each batch is being constantly baked prior to usage. We are currently purchasing a Sealer that can ensure the BGA are stored in an air tight seal ESD bag. I am currently Baking the BGA components ...
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Nov 7, 2001 |
BGA,s Storage 1 CAN WAVE SOLDER AFFECT OR DAMAGE BGA? Sure. Since you are vague, assuming: * Partially assembled board was not stored to prevent moisture absorption. * BGA is in a plastic package. * Partially assembled board was stored long enough to exceed the moisture absorption allowance of the BGA. * BGA is on the topside when waving. * Vias near the BGA pads are not plugged. So, here are a couple of possibilities: * Topside [and bottom side] temperature is ~200�F out of the preheater ...
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Jan 24, 2007 |
BGA opens / cracks Hello, we are facing some troubles with BGA opens in our production. PCB are both side popolated with BGA. BGA is array of 26*26, with some 6*6 center balls. PCB has 2 reflow processes, 4 pcs of BGA on each side. Now we are partly observing opens on the center balls on those BGA which have seen 2nd reflow process. Cross section analysis have shown micro cracks between ball and BGA pad. No crack between ball and PCB pad. Ball itselfs looks good, and also was soldered before on ...
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Aug 4, 2004 |
... under BGA Hi, Thanks for your reply. I run 2 boards, using the same paste, thermal profile and the same method of aqueous cleaning, 1st is a Topline test board with topline BGA (BGA 272 with 1.27 Pitch) and the 2nd is our product PCB with our BGA from Motorola (BGA 272 with 1.27 Pitch). The test board BGA seems to be fine, clean and without any milky looking Joint. Our product's BGA looked milky and the white residue is noticeable below the solder joint as if there's a gap between the BGA ball ...
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May 18, 1999 |
... BGA experiences... 1. REMOVE BGA, reball BGA, remove a ball from the BGA and replace it with a 30awg wire and protected using hi-temp solder and adhessive. Drill the pad all the way through the PWB, screen print solder paste using micro-stencil and placing BGA with the 30awg wire coming through the pwb. Reflow BGA using CONCEPTRONICS Freedom 2000 rework station. Attached 30awg wire to a via on solder side. X-ray and Ship. 2.Used the actual stencil to print solder paste on top of the balls of BGA ...
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Nov 17, 2008 |
BGA soldering & BGA ball formation I would not recommend doing BGA soldering with only a hot air gun. I have done it in the past, but the boards would eventually come back from the field because the solder joints did not form correctly and the BGA would have to be reworked again. In the event that I had to solder a BGA without a BGA rework station, I would at least want to have a bottomside board preheater so that I could preheat the PCB before I applied topside heat with a hot air gun. When I ...
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May 12, 2008 |
BGA Reworking on the cheap? Hi, there are different BGA packages, it's not same to rework LFBGA with 0.5 mm step and BGA with 1.27 mm step for instance basically you will be able to de-solder the BGA with hot air and proper nozzle which distributes the heat even on the BGA package, your problem will be later to may place and solder the new BGA on the board to place precisely BGA part you will need machine with split vision or some tool which to allow you to place the chip on it's board location ...
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Mar 25, 2010 |
... itself by lifting the BGA and testing the board for shorts and other issues. These tests showed no issues with the PCB once the BGA was lifted. We can tell that the BGA is the root cause of the problem, but not why. I am not sure at which temperature the wire bonding in a BGA geos critical and breaks. Would anyone know if that is a possibility, because the Broadcom BGA which we are working on currently has a built in thermal conduit from the top of the BGA where an external heatsink can be ...
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Aug 21, 2001 |
... process for BGA mounting? why not WS? 1) why is No-clean (NC) the preferred process, for BGA mounting by SMT? Probably the same reason NC is the preferred process for mounting non-area array SMT components. 2) why is water-soluble (WS) not a hot choice? There�s not reason not to use WS. Cleaning of assemblies featuring BGA devices may seem at first consideration to be fairly easy due to the large standoff height achieved by the balls. The difference between fine pitch QFP and BGA devices is ...
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Jun 2, 2009 |
BGA flux dipping process We have been doing BGA's for years now, and I would suggest updating your profile and place a thermal couple on the BGA, keep in mind the bigger the part the more heat it will need, We stencil print all of BGA's from simple bga's to complex ones, your stencil provider if they know what they ware doing will be able to work with you on the stencil thickness. (DEK Rules), I also place BGA's without solder paste. Heres the most important trick to BGA's BAKE them first, they ...
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Jul 24, 2002 |
... or even the BGA substrate itself. We find many BGA's that look acceptable visually and through X ray inspection. Black pad contamination is not visually or X ray detectable. It causes the connection to appear as an open during electrical test. Many people misdiagnose it as a defective BGA component. You can only diagnose this problem by removing the BGA and inspecting the PCB & BGA substrates. I suggest that if you can use a QFP rather than a BGA, then do so. If you must use a BGA and have ...
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Jan 18, 2001 |
... Dave, The BGA substrate surface finish is NiAu, while the PCBA pad surface is HASL. The solder ball composition is SnPb 63/37 and the solder paste used on the PCBA is also the same but with 2% Silver.>>> Dave, sorry I don't have the picture with me now to post. After sodering the BGA on to the PCBA, we peeled off the BGA's subsrate which left the ball well in tact on the PCBA, and we analysed the surface left on the peeled BGA's subsrate pad. That was smoother than a raw BGA's removed ball by ...
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Jul 27, 2005 |
BGA SEM test Issue: At 60'C test PCB Fails. Operator did simulation. Use of Heat Gun to heat up the BGA to 60'C while PCB is powered and running. At 60'C BGA fails. When pressed system is back which means that something becomes open. Sent BGA for SEM and found that there are cracks between the Nickel and the Copper layer of the BGA package where the joints are connected (BGA Package PAD). I was told that it is because of my thermal profile. Visited my profile and had this measured parameters ...
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Feb 20, 2004 |
BGA PROCESS MATERIAL We successfully clean WS flux on 1mm and 1.25mm pitch BGA. For 0.8mm pitch BGA, we use no clean, because we cannot remove the flux residue from under them efficiently. Use ion chromatography testing to be sure it is clean under the BGA. IC is the only way to be sure you can clean sufficiently. As a down & dirty method for determining capability of cleaners: * Make some glass [heat resistant tempered glass] slugs that are bigger than the BGA you plan to clean. * Glue several ...
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Apr 9, 2003 |
BGA Rework We've encountered a little problem with BGA's. There was a process problem in the build of the boards which has ment the BGA are failing open circuit due to the lack of solder paste. Any-one else had this problem? Any suggestions on solutions? We've tried replacing one BGA, but when the unit has been rebuilt and tested another BGA open circuit has been found on a different BGA. We also have the added problem of the boards being difficult in the sense we have to reflow the rework ...
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Mar 2, 2001 |
BGA Solder Mask Repair Frank, I am not talking about the masking on the PCB. I am actually talking about the masking on the solder side of the BGA. We have a very very high dollar BGA and are trying to reclaim alot for reuse. When we remove the BGA from the assembly, you have to do a little cleaning up before starting the BGA Re-Balling Process. Well by just using a soft cloth the green masking gets rubbed off the bottom of the BGA. WE are trying to figure out a way we can re-apply the masking ...
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Feb 25, 2010 |
BGA We are a small Contract Manufacturer and have received a project which has BGA's on top & bottom. 2 larger BGA's on one side (~_20x20mm) & 3 smaller BGA's (~_8x8mm) on the other. we plan on running the side with the smaller BGA's first but need some advice as to how to keep the 1st side BGA's from falling off when running the second side. Any advice would be helpful. Thanks
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Aug 11, 2008 |
BGA Detached off the board > I assume you mean the balls of the BGA, not pads > (laugh it up guys - I said balls). If so, you > may have a no-lead BGA or a high temp BGA. hi I mean that the the balls were left on the board and the BGA pads were found clean. What do you mean by "no lead BGA"? Thanks
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Jun 26, 2007 |
Lead-Free BGA Rework I have been trying to rework a lead-free BGA. For some reason, when I remove the BGA the corner pads on the board come off and the board must be scrapped. If I do manage to remove the BGA successfully, when I solder the BGA, the corners of the BGA warp up and doesn't allow me to get a good connection on the pads. I have tried using a larger nozzle, increased temperature, and nothing seems to work. the board is ENIG and it does contain a large ground plane ...
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Feb 9, 2007 |
BGA Tilt 0.25mm tilt? That's pretty small depending on you BGA size. Is it failing? Or just your Q.E. being anal? What size BGA we talking about? What ball count? Just one board? Maybe cheaper to just repair. Now assuming there is NO part under the BGA: First check your board. Are all pads the same size? Most board houses will cheat on pad openings. If not check your Gerber to be sure you are asking for same size on all pads. Next, check your part. Missing balls can cause tilt. Check your balls ...
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Oct 30, 2006 |
Flux residue cleaning procedure As we understand it, you: * Get some nice BGA from your supplier * Find BGA to be packaged properly * Bake the BGA for 24 hours at [what temperature?] to reduce the potntial for damaging moisture sensitive components during following processes * Remove BGA from oven and prepare to rework a board * Observe the BGA making poor contact with the board, because the BGA connector balls are coated with a white residue What changes would you make with this interpretation ...
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Mar 13, 2006 |
... issue was Co. does not need to go Pbfree, but some BGA's they use are only available Pbfree. They don't want to throw away Pb BGA stock, so some boards might have a combination of both Pb and Pbfree BGAs. The question basically was Should they solder with Pbfree solder (because of the Pbfree BGA), even though there would also be Pb BGA on the board? The first poster said no, this would give voids in Pb BGA. I responded that soldering Pbfree BGA with Pb solder would give reliability issues ...
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Mar 22, 2005 |
... you guys doing for filled/tented/plugged vias on the BGA site? A2. 2221A, 4.5.1 tells you the vias have to be tented on both sides. Q2. What type of issues can this cause if using no filled/tented/plugged vias on the BGA site? A2. BGA via with no tenting, plugging, or filling allows: * Via to scavange solder from the BGA solderball connection. * Heat from wave solder pot to reflow BGA solderballs. * Solder from wave solder to wick to the BGA solderballs. Q3. What type of issues can this cause if ...
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Apr 13, 2004 |
... for No Clean BGA Balls Q1: Can anyone explain to me about the effect of their mixture. A1: What is their �mixture�? Q2: What enhancement does my BGA will have when using a WS paste flux with regards to corrosion, 25 years life cycle of the solder joint. A2: Tough to say, which board has the lower level of harmful contaminants? Q3: What's the benefit in using a WS paste flux on a BGA with No Clean solder joint process? A4: Assuming you solder NC / paste, reflow water washable BGA / wash, you ...
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Sep 29, 2003 |
What causes Bga corners to lift during reflow Hi Mantis. Has there been any changes in the BGA itself? One of our BGAs changed to a newer type, and after that we had problems with corner lifting. In that case problem was BGA's structure, there was mismatch in TCE between BGA's substrate and molding compound. There was nothing to be done, but change the BGA for that older type again, since the problem was in the BGA itself, not in our proces. br, Sam
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Jul 31, 2003 |
SRT -1000 BGA rework system A couple of things you can look into 1. The proper bottom pre-heat of board. If you are applying only direct hot air to BGA without preheating can cause BGA's to warp and collapse un-even. 2. Moisture on you BGA's. If BGA's were not properly packaged moisture can hot air balloon the BGA ...
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May 15, 2003 |
BGA shorts that can't be found. Have seen similar circumstances a couple times. Possible causes: 1) PCB defect - remove the BGA and inspect/test the PCB for shorts. ( trace short, layer short etc ) 2) PCB defect that only shows up when the BGA is populated - a short somewhere on the PCB, and the BGA is not the fault, but part of the circuitry. Remove the BGA, short dissapears. Replace the BGA, short returns. These are the fun ones to find Good luck! Phil
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Feb 18, 2003 |
BGA shorting Haran: Have you made improvements regarding your BGA shorts? We are facing the same problem and we think it is partly because the non coplanarity of the seating plane of the BGA which causes BGA balls to squeeze on one side of the BGA. Also, we have found that the seating plane thickness is sometimes larger than the BGA balls which lead us to have opens instead. Arturo
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Oct 30, 2002 |
BGA Short Have you tried doing a reflow of the BGA with the connectors removed? This should solve the question of connector proximity giving you a problem. Also, try rotating the board 90 deg in your rework station before reflowing a BGA. Be sure to rotate the BGA the same direction. This will help you find out if a nozzle problem exists. If the defect still occurs on the same sides of the BGA (closest to the connector) with the BGA and board rotated, there is most likely a nozzle flow issue. If ...
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Aug 15, 2002 |
void on BGA Ball due to via on BGA pad To whom this may concern, I recently ran into the problem with vias on pads of BGA when place BGA and reflow gas trap on vias escape and result in ball having void greater than 50% of BGA diameter. The BGA pad is measured at 20 mils and the vias measure at 10 mils. These vias are drilled only from layer 1 to layer 2. Some vias can be seen with a microscope, other was capped or partially cap through a HASL process. So would anyone has any suggestion on how ...
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Aug 10, 2001 |
Micro BGA baking Hello Friends, Please advise how critical is the Micro BGA baking? The BGA size is around 7x7mm and we need to program it before mounting. The Micro BGA's are supplied in Trays and are put in to tape and reel after programming.We need to put these BGA's in to tape and reel due to Pick and place machine limitation. The Micro BGA's are 32 mils pitch and 10mils dia. Thanks, Praveen
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May 4, 2001 |
BGA CORNER WARP BGA warpage combined with PCB warpage can lead significant process yield loss. First, it is possible that major portion of BGA's apparent warpage is, in fact, coming from the PCB warpage. Assuming that the warpage is solely from BGA itself, I think unfortunately there wouldn't be any root-cause solution other than changing the BGA package design. Your observation on the relative thinness of the BGA substrate suggests that the warpage is most likely due to the inadequate package ...
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Mar 30, 2000 |
... plugged via under pad may also create a void in molten ball. Typically most voids are detected in the middle to top (ball / BGA interface) of the reflowed solder joint. This is expected because the entrapped air bubble and the vaporized flux, which is applied to the PCB BGA pads, rises during the reflow profile. This occurs when the applied solder paste and the BGA's collapsible eutectic solder ball(s) melt together during the reflow profile (typically 235 to 240 *C peak temperature). If the ...
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Nov 14, 2002 |
Help! BGA Socket / BGA Direct Placement Kevin, I have done the following process to a similar problem: 1. Plug holes (even to both sides of the board) 2. Clean any flux left on the surface, especially on bottom side. 3. Apply Kapton tape to the bottom side, you mite want to apply 3 layers. 4. Apply a small layer of paste flux to the top side. 5. Apply BGA and Reflow. Note: Applying paste flux will only work if attaching a plastic BGA with SN63/37. If you are applying a Ceramic BGA with SN 90/10 ...
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Mar 23, 1999 |
BGA USAGE IN THE INDUSTRY? I WORK FOR A SMALL TO MID-SIZE CONTRACT ASSEMBLY HOUSE. WE ARE TRYING TO FIND ANY SURVEYS OR STUDIES DONE ON THE USE OF BGA'S BY COMPANIES ON NEW DESIGNS. THE WAY EVERYBODY'S ALWAYS TALKING ABOUT BGA'S YOU WOULD THINK THAT THERE WILL BE NOTHING EXCEPT BGA'S ON BOARDS 10 YEARS FROM NOW. NONE OF OUR CUSTOMERS AT THE TIME ARE USING ANY BGA'S. ANYWAY, MY MAIN QUESTION HERE IS IF ANYBODY OUT THERE KNOWS OF ANY STUDIES OR SURVEYS THAT BREAK DOWN THE MARKET ON PCB DESIGNS AND ...
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Feb 14, 2001 |
BGA shorts BGA Shorting 1 Damaged mask in between the BGA pad and via on the substrate. 2 Poor print registration. 3 Poor via segregation from the pads? Are they tented or is there just a dam in between? 4 Review the profile. You can run into a number of problems in BGA rework, if the profile is incorrect. 5 An inert reflow atmosphere helps 6 Solder shorts: Moisture entrapment causes solder shorts 80% of the time. Cracks occur bottom side. Use acoustic microscope to find. 7 Warping BGA are the ...
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Jun 27, 2001 |
... with reworked BGA. Others routinely replace the balls and re-use the BGA. [Here�s a take on Motorola�s thinking on repairing BGA. As a minimum => BGA Cycle 1: solder ball attach. BGA Cycle 2: BGA attach to board. BGA Cycle 3: BGA removal from board. BGA Cycle 4: BGA pad dress. BGA Cycle 5: BGA ball replacement. BGA Cycle 6: BGA re-attach to board. Board Cycle 1: BGA attach to board. Board Cycle 2: BGA removal from board. Board Cycle 3: board pad dress. Board 4: BGA re-attach to board.] ECO ...
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May 25, 2009 |
BGA ball vs land design problem?? Hello, recently we changed supplier of the LF BGA, we did corossection and now have doubts... previous BGA specs : pitch 1mm, ball diameter 0.6mm future BGA specs : pitch 1mm, ball diameter 0.4mm on the crossecrion we found that one of the ball seems cracking from the package - under x-ray we saw void in other ball but this one seem quite normal, checking more BGA under x-rays show more voiding that on the opponent (previous) parts land pad on the PCB is 0.45 ...
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Jan 14, 2007 |
... BGA. * Using a syringe to dispense lots of a low melting point solder under the BGA. [Use an alloy with a MUCH lower than the near eutectic solder that you commonly use. Ask your paste supplier for suggestions. Try to avoid using alloys containing bismuth, because of potential reliability issues with high operating temperature equipment.] Then doing BGA removal. OR Remove the BGA by cutting the board, the dunking the BGA in a solder pot of near eutectic solder. ----> Pre-heating the board is now ...
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Jun 27, 2006 |
BGA Vs. QFP I don't understand why you think a BGA would be better than a QFP. Half the process questions I see on this forum seem to deal with BGA's, and the switch to Pbfree processing is a far greater hassle - Pb free QFP's will be compatible with either process. The debate still rages here monthly about using BGA's in mixed process. The main benefit of a BGA over a QFP is it uses less real estate. If the designer has the room to use a QFP, I say, let him do it. A part we use in our facility ...
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Sep 20, 2005 |
BGA relow without solder paste? HLY: If you must build product while you wait to get the printer fixed, and if the BGA balls are eutectic solder, your approach is a good one. All solder paste does in this assembly application is supply the flux. Additional solder volume is not necessary. I've done quite a few BGA repairs using a Metcal BGA rework station. In those cases, I would apply the "gel" flux to the BGA balls by pressing them into a well of "gel" flux of a controlled depth (approx 14 mils ...
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