|
The Knowledge and Know-how Connection
|
|
June 18, 2013
|
|
|
|
|
|
|
More Related Programs »
|
Featured Sponsor - please stay tuned ...
»
Accurate Force Measurement SolderabilityTesting
Force measurement solderability testing verifies the robustness of the component or board termination. The Gen 3 Systems Must 3 measures forces at milli-newton levels accurately and easily.
Gen3 Systems Limited
Do BGA Components Warp During Reflow?
We recently reworked a BGA component and the corners all bridged. Can these components be removed and reused if we remove the warp? What causes the corners of the BGA component to warp and how do we prevent it?
Board Talk is presented by ITM ConsultingVisit ITM Consulting to learn more.Phil Zarrow, ITM ConsultingWith over 35 years experience in PCB assembly, Phil is one of the leading experts in SMT process failure analysis. He has vast experience in SMT equipment, materials and processes. Jim Hall, ITM ConsultingA Lean Six-Sigma Master Blackbelt, Jim has a wealth of knowledge in soldering, thermal technology, equipment and process basics. He is a pioneer in the science of reflow.
|
|
Sponsors
»
|
High-Speed Counters for Taped SMDs
Zip through 7-15" reels for fast, accurate inventory & kitting to preset quantities. Bar code scanner, labeler & empty pocket detector. See video.
Manncorp 
|
Heller Shanghai Celebrates 10 Year Anniversary
Heller will be celebrating its 10th year in Shanghai, with manufacturing, R&D Center and Applications Lab. Congratulations! Click to learn more...
Heller Industries Inc. 
|
Moisture Damage Causes Early Field Failures
All components are susceptible to moisture damage. Even PCBs. These defects can pass through ICT and functional test and they lead to early field failures. Is your CM in control of MSDs?
Super Dry® by Totech 
|
Quickturn now includes Slots & Cutouts
You can now select Slots and Cutouts on Quickturn orders with lead times as short as 24 hours, and at a lower price than ever before. Learn more...
Sunstone Circuits 
|
Why Use EMI / RFI Shielding
EMI / RFI shielding products protect electronics from damaging electromagnetic radiation. Learn more...
Diamond MT 
|
|
|
|
|
Views: 2036
|
Matching the nozzle size to the BGA is important to minimize the warping of the part during rework. Using a too small nozzle requires all the heat to pass thru the part and into the solder joint. This can cause large temperature differentials and result in BGA warping. A properly sized nozzle - one that is approx 2mm all around larger than the part will allow heat to flow directly onto the PWB and reduce the intensity of the profile. A less intense profile (temp + flow rate) will help to prevent the temp differentials that can cause the BGA to bow down and create corner shorts.
Jerry Wiatrowski, General Dynamics C4 Systems, USA
Does the shape (square vs rectangle), size (large such as 1.25" sq. vs small (say 0.50" x 0.75") or material (such as all plastic or a die on a small PCB) affect the amount of corner or edge warping. At our company, we have the most trouble with memory devices which are plastic and are about 0.5" x 0.75". We rarely have problems with BGAs such as CPUs which are about 1.25" square and have a bonded die flip-chipped onto a small PCB.
We also think that RoHS solder makes for trouble in attaching BGAs. We know of a couple of companies that routinely remove RoHS solder balls and replace them with eutectic lead-tin solder. The tin plus a pinch of this and that metals don't melt uniformly and require a hotter reflow. Since not all component solders are equal for a given BOM, the assembler has to use best judgment to pick the reflow temperature and dwell and ramp-up and ramp-down times.
Bob Anslow, Dynatem, Inc., USA
Main cause behind warping of BGA components is excessive moisture contents in the package. Another reason can be some mismatch between the various components that make up a BGA Package (i.e. the substrate, molding compound and silicon chip).
Later one is the package manufacturing fault and these type of packages require special care while designing the reflow profile.
Whereas if the reason is excessive moisture, special care should be taken while baking.
Maninder Singh, Deltron (A Div. of CDIL), Chandigarh, India