Order by: Relevancy | Date
May 1, 2007 | Hi, We are encountering BGA problems where it dislodge from the board. Some are just by normal hand
Apr 30, 2007 | I'd also recommend Control Micro Systems;4420 Metric Drive; Winter Park, Florida. We've been using
Apr 24, 2007 | If the PCB you are using is a HASL pad finish and is a leaded assembly, we use homeplate pads with a 5 mil stencil. If the circuit has Enig finish and is PB-Free then we use 1:1 apertures with a 5 mil stencil Either method should provide no solderballs and good fillets for 0402 passives. Good
Apr 12, 2007 | Our SMT production and storage area is air-conditioned, constant temperature is maintained but the humidity is not controlled , the raw SMT material is stored in a "Drier" cabinet, but since we assemble hybrid SMT and thru-hole PCB assemblies, the SMT subassemblies are not kept in a humidity
Mar 30, 2007 | We have now ordered a another stencil with square apetures with 20% overprint just because it is so difficult to get the solder paste to stay on the pcb pads without to get it stuck within the apertures. We have set the print speed down, the separation speed down etc. etc. We are just going to try
Mar 29, 2007 | Hi George, Depending on your product, wave soldering twice is not all that bad. Residues will be
Mar 20, 2007 | Could you use a conductive PCB holder rack instead of a box? check out http://www.stanleysupplyservices.com/product-group.aspx?id=874 for what I have in mind.
Mar 15, 2007 | There is no IPC document, nor should there be.
Look here: Mar 14, 2007 | I have a customer that designed a fine pitch BGA into a board, and has put small vias in the middle of each pad on the PCB. Anyone have any ideas on how I can prevent the solder from the BGA from flowing through the vias and causing voids or no contacts on the BGA solder joints?
Mar 14, 2007 | I have a customer that designed a fine pitch BGA into a board, and has put small vias in the middle of each pad on the PCB. Anyone have any ideas on how I can prevent the solder from the BGA from flowing through the vias and causing voids or no contacts on the BGA solder joints?
Feb 15, 2007 | Has anyone any ideas where I can purchase replacement parts for my Quad QRS VII Reflow Oven? Recently had a failure on the Machine PCB 8367, resulting in message error, stating "message took too long to respond". Just looking for help to keep the machine going
Feb 9, 2007 | CHECKS FIRST that your BGA doesn't tilt from pick & place machine. SECOND lead free paste have some problem that it solder the component whereever pick&place put the component while solder pastes having lead, put the component on its PCB pad like a magnet then reflow it. THIRD follow
Jan 30, 2007 | Thank you for feedback and comment. We are trying this again, increasement of solder temp to reach 210-215 peak temp. This is also our norml guideline, but in the past the colleagues had observed problem with that PCB, so reduced it. I let you know the result. Currently we wait for materials
Jan 18, 2007 | Production reject IC short? So there is a solderbridge on your IC? What type of IC? A few things to consider: 1.- Too much paste during screen printing because you may not have enough PCB support You need to provide as much details as possible ( type of paste, type of IC etc ) other wise
Jan 18, 2007 | Wondering if anyone is using cleaning solutions that are safe to use and store, and don't cost an arm and a leg. Cleaning tasks would include solder paste stencil cleaning, misprinted PCB cleaning, flux cleaning after rework, and so on and so forth. Would really appreciate your advice.
Jan 15, 2007 | Having problem with a 2X50 SCKT Strip PTH component(fine pitch) bridging on the wave. The PCB runs in wave pallets. Just wanting to know what successful findings have been done to eliminate bridging? Pallet angles? Copper or titanium inserts? Air knife? Lead lengths? What works well?
Dec 29, 2006 | About one year we have that problem with some of pcbs. Our customers told us about that. Because they can't mounting components on those pcb reason of flux residue. As you know flux not conductive chemical. We didn't change anything before having that. Now we think that we must change operating
Dec 18, 2006 | Hi, Yes, I would hate to resort to cleaning, but the product must be clean. We have been using palettes to keep most of the flux off the PCB, but there is still residue around the connectors. Does anyone suggest a good no clean flux to use with lead free process that leave as little residue
Dec 18, 2006 | Hi, We have a white residue, which is visible, and we would like to have the produce clean as it's a PCI card, so users see the PCB. I am wondering if we need to install a cleaning stage to the line for these kinds of products. Can anyone give some advice on that, and do you think its a good
Dec 15, 2006 | Hello All, Is Ionic Cleanliness testing using say an Ionograph on No-clean assemblies a valid test? If not, why? I understand factors like PCB cleanliness but is the 1.56ug/in2 IPC criteria valid for no-clean assemblies and can an Ionograph be used to pass that criteria for No-clean?? Thanks
Dec 7, 2006 | You have two options 1. Get some real solder mask form board supplier (not touchup pens) and repa
Dec 6, 2006 | Hello, we rework BGA packages that come back from the field. I've seen on occasion a black and or red "epoxy" substance from the manufacturer on the corner of some board's BGA chips that I imagine are applied to increase corner bond of the chip to the PCB. My question is what is this stuff called
Nov 30, 2006 | Thanks for the replies, it is getting clearer now. We called a PCB supplier and acted if we didnt know what was what, he actually told us its all the same, chemical, flash, immersion, all the same... It is now getting clearer why we are sometimes getting soldering issues with matte looking gold
Oct 31, 2006 | SWAG - Was your experiment on the board with the large ground plane? The board we are seeing issues with also has a large ground plane (approx 50% of PCB), and 90% of the delamination occurs in that area. The delamination is about the size of a silver dollar. We are currently running some life
Oct 31, 2006 | thanks for your reply, actually we bake the PCB assembly prior the rework because the package was exposed for quite some time already. The baking time was 24hrs @ 125 deg.C. We notice that there were flux residues on the connectors after the baking. We just neglect it and we proceed to BGA rework
Oct 30, 2006 | I have some problems in sufficient preheating the pcb's. They splatter on the mainwave, causing solderballing. Less flux causes problems with the fill of the through- holes. We use a Delta Wave with 3 preheat zones, the first two are calrods the third is a IR zone. This configuration was advised
Oct 2, 2006 | Assuming: * Customer board has been designed to provide for cleaning under components. * Cleaning
Aug 31, 2006 | Many thanks Saaitk, The PCB to protect could be (fuel cut off control system against tiefs ...)located in between driver cabin and engine. I have done a quick look on HumiSeal Automotive Products, found Acrylic Resin, Model 1B66 should be a suitable resin. Any experience available on this forum
Aug 31, 2006 | GS, Resin choice is really dependant on what you are protecting the PCB from. I would suggest that AR or UR would be the 2 that may be most suitable. Material manufacturers can give some good advice on material properties would be worthwhile giving them a ring and getting their recommendations
Aug 28, 2006 | Being the Lead free material would be more fragile it would have more of a tendency to fracture the
Aug 28, 2006 | Sounds like your PCBs are now white tin. Change this to another roHS compliant finish and see if prob goes away. You must get control of the materials that you are being asked to build. Your Customer needs your advice on surface finishes, they should not be talking with the PCB suppliers
Aug 9, 2006 | Trace repair is dependent upon the operator. A highly skilled operator can repair a trace with no a
Aug 9, 2006 | Use ENIG, plated finish will be too thick and make for a brittle joint. ENIG is self limiting so thi
Jul 28, 2006 | Thats a great idea Doc. If we all listened to your suggestions, there would be zero defects in PCB manufacturing. I bet your using Bahodum solder which, I'm sure, is incapable of defects. Pavel, sounds like you can rule out reflow as the problem. Let us know what you come up with.
Jul 27, 2006 | of pcb manufacturing, he should be able to answer this one.
Jul 20, 2006 | Hi Folk, i am wondering why they are Missing ELCap and ELCap being totally shifted out of the PCB Copper Pad during the SMT Reflow. Recently we have encountered some boards with the above mentioned symptoms. Appreciate if anyone could advise me. Thks & Rdgs CKH
Jul 20, 2006 | John S. Bill Csonka of Photocircuits Inc. here again. Photocircuits does have the latest TS1694
Jul 17, 2006 | Hello there, I'd love to have HR at 50-55%, but also temp at 21-23 deg C, with hot start of summer in Poland, we have on prod.floor close to 30 deg C and 30%HR, it is really difficult to print properly and to get pcb through oven without problems... last wednesday we went to 32 deg C and lots
Jun 29, 2006 | Hi I manufacture a range of components with Ag,Pd,Pt terminatons. Has the solder wetted to the componet and is the termination still left on the component? I would expect the solder to remain on the pad though, if all your other devices on the pcb are soldering ok it should still be there. One good
Jun 26, 2006 | Through the pads of conncector(50pin) were printed full solder paste, the solder paste of about 2-5 pads follow to bottom of the connector 2-5 pins, the 2-5 pads outside of connector no any tin after reflow. Is this PCB problem? I can supply failure photo for reference, how to attach?
Jun 21, 2006 | I've been building boards for a long time and have never heard of anyone using electrolytic silver.
Jun 18, 2006 | Please specify your needs. If you want to use a Fuji CP6 ship-shooter for chip placement on a pcb that are already glued before in an earlier process; the answer is yes. But the CP-6 itself can't handle the glue process, since it is a pure placement machine. /Sincererly
Jun 9, 2006 | So sorry sir Fastec, but I am Mumtaz, not Guru. Call me a troll, but I have been a part of pcb assembly since it's inception. I speak from experience but also am eager to accept new ideas. Yes, I know the Guru may be playing us as fools and his processes are very rediculous, but one never knows
Jun 1, 2006 | Hello, We repair mobile (cellular) phones, and most are now having their u-BGA IC's underfilled. Can anyone suggest methods for removal of the IC's ? The manufacturers are very vague when it comes to this process, but are starting to get tired of us replacing PCB's just because a glued IC
May 30, 2006 | For Trion 2340-Orbotech AOI is not so hard to handle this automated machine, specially for offline PCB test inspection, since it only used black and white color configuration. To improve its testing capability, try using the BRIGHT_A or BRIGHT_m function which differ on brightness of the shadow
May 27, 2006 | HI, just my 0,00001 cents Which preheat system does your wave solder has? for instance ? - IR ? - Bottom only ? - IR + Forced Air ? (bottom) - IR + Forced Air (bottom) IR top ? PCB thickness ? Appropriate preheat is important when looking to fill up holes. Best Regards .......GS
May 23, 2006 | Had exactly the same type of issues. Tried everything from pre fluxing the pcb's , various ammendements to the oven profile and various pastes. Finally after a lot of help from multicore we settled on a paste by the code of cr39. A no clean flux with a more active flux. May I also recommend Tamura
May 16, 2006 | . Optimizing the PCB layout is not always an option. Comments?
Apr 26, 2006 | Hi all, Has anyone any experience they can share with regard to pad dissolution on PTH's on thick
Apr 19, 2006 | Many times a pad that has no signal trace going to it will come off. It does happen from heat and t
Apr 18, 2006 | ...did not work for us....with large ground planes on the PCB, cycle time just became unrealistic. Regards, George
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