"voiding" search results in the Electronics Forums

1078 result s found for "voiding" in the Electronics Forums

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Conformal Coat

Jun 24, 2019 | yes, the void should not expose the conductor or bridge the conductor, the coating there should be thick as IPC required but you need minimize the voids and bubbles. ALso for those small chips, a void or bubble on it means possible ECM, normlly should not has void or bubble on it because it

What is the QFN or Device Voiding Levels Needed for Automotive Industry for Power Devices for Electric Vehicles?

Mar 15, 2017 | What is the QFN or Device Voiding Levels Needed for Automotive Industry for Power Devices for Electric Vehicles? Customer precedes standard, but customer must be educated and informed on what is achievable with their design and what is accepted as industry standard practice. My guess is that the negative effect of those voids is negligible. {Voids at the solder interface on the thermal pads} Here is a fact that I do know. People get nervous when they see voids in an x-ray image.

What is the QFN or Device Voiding Levels Needed for Automotive Industry for Power Devices for Electric Vehicles?

Mar 15, 2017 | What is the QFN or Device Voiding Levels Needed for Automotive Industry for Power Devices for Electric Vehicles? From what I know, you should follow IPC standard for the class assembly that you are building. From your post somebody mentioned something somewhere - doesn't make it official information. I would not be worried about having voids, but what is their location and size. You absolutely don't want voids on your signal pads of the QFN. Big voids lead to failures. I have read several articles, claiming that small voids actually improve the strength of the solder joint. Solder paste and proper stencil design help reduce voiding.

Voiding measure

Jul 13, 2016 | Voiding measure Guys I'm looking for a software on the web that I can use to do void measurements. I have x-ray images but unfortunately no software in the machine to be able to calculate void size. Thanks in advance for your support.

Does IPC definition for "QFN Void Ration" ?

Aug 10, 2014 | Does IPC definition for "QFN Void Ration" ? Does IPC definition for "QFN Void Ration" ? Like IPC 7095 susgestion the BGA Void ratio.

Voids with LGAs

Jan 17, 2013 | Voids with LGAs We have got lots of voids at ALL LGA. Anyone has ideas to get rid of this issue or just minimize the size of voids ?. With the same paste, same reflow oven, looking good profile, we don't have that problem with BGA. Thanks.

SMT voiding

Oct 25, 2012 | SMT voiding Here's a paper that may help http://www.ipcoutlook.org/pdf/assembly_challenges_bottom_terminated_ipc.pdf Temperature Impact * Profile didn’t have a significant impact on voiding . * Voids slightly increased with higher temperature. Reflow Atmosphere Impact * Nitrogen didn’t help to reduce voiding amount * Nitrogen could result in less voids but larger voids. Orientation Impact * Orientation didn’t impact the voiding significantly. SMD vs. NSMD Pad * There was no significant

N2 and Voiding??

Oct 17, 2012 | N2 and Voiding?? Has anyone ever experienced void increase while using N2? Thanks for the Help!! anvil

Void control

Oct 11, 2012 | Void control We are experimenting with void control in reflow and have had pretty good luck for the most part in attaining Class lll IPC spec. but we have seen a sudden increase in voiding on a specific product and I was wondering if anyone has seen this extreme voiding before? We were wondering

SMT voiding

Sep 30, 2012 | SMT voiding We believe that Dave's analysis above is mostly accurate. Run a board with no components, and check for voids. We'd also like a little more information, though, to clarify. What type of component is experiencing the voiding? You describe the voiding as "under" the component...are we talking about ground pads, or blind lands under components? The types of lands that are prone to voiding due to the mechanical nature of the part? Is the voiding isolated to any particular area of the board/components? Is the voiding isolated to a single assembly for you, or is it being experienced across

Depanneling Problems

Feb 19, 2011 | What kind of voids? There are voids from out gassing (moisture) and voids from contamination and or poor solder ability ? If it is on one component I would look at the part. Also if it a big Varistor make sure the board is preheated properly.

Voiding in LGA (LT) soldering

Sep 1, 2010 | Voiding in LGA (LT) soldering Dear Sachu_70, During the tests we also checkt other devices, there are a few small voids visible, but they are marginal. We only see large voids in this device. During the testruns we tried several reflow profiles, but without large succes.

BGA Solder Voids

Jun 14, 2010 | BGA Solder Voids What can I do to reduce BGA solder voids?

BGA Voids

May 21, 2010 | BGA Voids Erli, Thanks for your feedback. The BGA hybrids were baked before production. I had a particular date code that we dis-continued using. This date code was consistently voiding near or above 25%. The other date codes still produced voiding on average around 12-16% void sizes which is a process indicator. The manufacturer of the BGAS seems unconcerned if the voiding is under 25% citing the the "Hole-in-pad" issue. All of the other assemblies that I build have no measurable voids. I do get a occasional void of around 5%. Thanks...

BGA Voids

May 20, 2010 | BGA Voids Unfilled vias consistently produce higher quantities and larger voids than filled vias, in some cases 5 times as much. [Effect of Filling Via-in-Pad on Voiding Rates in PWB Assembly for BGA Components; C Shea, R Raut, L Piccione; ALPHA -A Cookson Electronics Company]

BGA Voids

May 19, 2010 | BGA Voids Hello, I'm having problems with voiding on an assembly that has a GPS hybrid with balls much like a BGA. This is a RoHS assembly using no-clean solder (Kester EM907). The voids are at or above 25%. I use an 8 zone oven where I peak in zone 7 and use zone 8 as an extended peak. I've tried RSS and RTS profiles with no change in the voids. I've tried following the profile recommended by the paste manufacture and profiles recommended by the GPS hybrid datasheet using an ECD Megamole 20. I contacted the GPS hybrid manufacturer and got the following response: "Since the soldering pads

Solder void underneath the mosfet

Mar 26, 2010 | Solder void underneath the mosfet What about thermal cycling and/or vibration over the long term? My guess is that with the voids the joint would not be as reliable long term as a joint without the void. Am I thinking correctly?

How much voiding to allow on QFN's

Jan 12, 2010 | How much voiding to allow on QFN's What is your concern regarding voiding in QFN solder connections?

How much voiding to allow on QFN's

Jan 11, 2010 | How much voiding to allow on QFN's I know IPC is working on a spec for voiding for QFN'S. However since its not released I'm curious what others have defined as the max allowable % voiding on the leads (not center ground).

BGA Voiding for RoHS

Nov 13, 2009 | BGA Voiding for RoHS Could you clear how much void content do you client required? Normally, 5% void content is permited in clients.

BGA Voiding for RoHS

Nov 10, 2009 | BGA Voiding for RoHS I'm curious why your customer is concerned with BGA voiding. Normal process voids, even well in excess of IPC "limits", don't effect reliability so why monkey with the process to get rid of a non-issue?

QFN Thermal pad voiding

May 15, 2009 | QFN Thermal pad voiding Hi all, Is there any standard for percentage voiding on the center thermal pad on a QFN? We use the dot matrix array for paste to allow for outgassing etc, but we have had a couple of xray inspection "fails" for voiding on this pad , in or around 30-40% voiding. Is this not normal considering its

BGA voids

Apr 23, 2009 | BGA voids That you have one BGA of 30 BGA that has voids, makes us wonder what's the deal with that one BGA. Especially given that this is the initial run of a product with BGA at your plant, it really makes us want to understand just what is driving the voiding in that part.

BGA voids

Apr 23, 2009 | BGA voids During initial profiling we shoot for 15% or less voiding on our BGAs. During production runs we consider voids under 15% to be ok. Voiding between 15%-25% we string tag and pay more attention to during test. Over 25% we consider a reject.

BGA voids

Apr 23, 2009 | BGA voids Every paper I've seen published shows that BGA voids either have no effect or actually give a slight improvement. The one exception are voids with a root cause in bad incoming boards, such as champagne voiding where nearly the entire interface is gone. I've done thermal cycling of BGAs(-40/+125C and -40/+150C) and found voids had no measurable effect on reliability, including voids up around 35%. I have no idea what the words "process indicator" means in this context and wish IPC-610 hadn't used them. If voids aren't a defect, what are they indicating? Why would I monkey with my process

SN100C Selective Solder Voiding

Nov 12, 2008 | SN100C Selective Solder Voiding Jim, We are experiencing voids, also at Selective, on a transformer with known flux residue issues. The supplier told us they were using a OA, or RMA flux which has to be cleaned, and we accepted these parts anyway. How does the "separation speed" parameter affect voids?

Voiding In BGAs

Nov 6, 2008 | Voiding In BGAs IPC only allows 25% max voiding. We are able to run at levels much lower than 25% by using a heller 1800 reflow oven. Have not been able to eliminate voids completly. Not even the worst case have we been above 20%.

Voiding In BGAs

Nov 5, 2008 | Voiding In BGAs Take a look at your profile. Early on in the development of our leadfree process we saw excessive voids on BGA'S. We tweeked our reflow profile and were able to bring our voids down to about 9% or less. Also found that some paste mfgs. worked better than others.

Voiding In BGAs

Nov 4, 2008 | Voiding In BGAs Anyone have any advise on reduing voiding in BGAs using a SAC305 solder paste?

QFN void issue

Jun 20, 2008 | QFN void issue Hi all, any good recommendation for PbF paste application to reduce voids underneath the QFN thermal pad (stencil thickenss? opening? via hole? reflow profile etc)? We have tried few stencil opening design but no significant improvement as seen. There will be about 50% or above of voiding in the total pad area. Is is possible to reduce the voids below 50% or any industry standard/spec available for QFN voids? Thanks a million! B. Rgds, Phil

Solder voids in PTH

Feb 19, 2008 | Solder voids in PTH Do you of reducing hole size of DIMM connector will improve solder voids??

BGA Voids

Feb 13, 2008 | BGA Voids Larry, from my days of working for a Telecom. company, Bellcore standards (now Telcordia) was our BGA Void guideline. There was some verbiage in the guideline that accounted for allowable VOID VOLUME ...keep in mind, VOID AREA and volume are 2 different things. The 2D x-ray that we used measure void AREA (not volume). That being said, we took the area measurement, and coverted it to volume - example 13.5% area void translates to 5% volume void (it's all from your high school gee-i'm-a-tree class). The QE's in your company will love this. See attachment for details. (THANKS SMTNet

Voiding in Underfill process

Jan 23, 2008 | Voiding in Underfill process You can do a destructive test to sort of check your process. Break off the flipchip and look for voids. I have used Namics 8437-2 for the last 7 or 8 years. Good stuff. Flows under a 0.001" gap with no voids. Chris

Voiding in Underfill process

Jan 21, 2008 | Voiding in Underfill process Is there a tool to check for voiding in a Underfill process?


Sep 17, 2007 | Void We have never studied this, but here's what we'd guess. If there are void in BGA solder balls at inbound: * A proper reflow recipe will eliminate the void. * A poor recipe will allow the void to remain and possibly generate additional void.


Sep 6, 2007 | Void Can voids be carried over from original voids in solder balls during reflow?

voids when waving

Mar 12, 2007 | voids when waving Have you checked the parts for contamination? Are the voids out of spec? IPC allows some voiding, especially with lead free solder. Component contamination can cause this to repeat, as well. Try pre-tinning the component in question, and see if suddenly you get better solder joints. Check

Soldering to an OSB surface

Jan 12, 2007 | OSB ??? OSP !!! 1. The longer the soak, the fewer the Voids. 2. The Higher the soak, the fewer the Voids. Options 1 and 2 have downsides. You could call your paste supplier and see if they have a low-void solder paste... most likely formulated for "micro-via in pad"

SAC solder balls reflow with Sn/Pb paste - Voids Issue

Oct 5, 2006 | SAC solder balls reflow with Sn/Pb paste - Voids Issue I have noticed certain BGAs void more than others. We place about 8 different brands of BGAs and only one brand voids like crazy and we have to adjust for it.

Imm Silver and Voiding

Jun 23, 2006 | Imm Silver and Voiding Some amount of voiding was always seen on sites where solder paste is printed. These voids are much smaller. However the site where a flip chip is flux dipped has never had problems with voiding. Macro voids (and huge ones at that)across the board surfaced recently, both on sites with solder paste

Imm Silver and Voiding

Jun 22, 2006 | Imm Silver and Voiding First, we expect voiding in imm silver to be similar to ENIG. We expect more voiding in OSP than other common solderability protection. Second, choosing a solder paste, which does not contain resins and activators that decompose at higher temperatures, is the primary factor in void reduction . Third, tell us more about your: * Solder paste * Thermal recipe measured at voiding site * Breadth and scope of problem

Imm Silver and Voiding

Jun 22, 2006 | Imm Silver and Voiding Hello, Has anyone had issues with voiding while using Imm Silver PCB finish. Does thickness of silver, contamination of the plating bath or other factors if you come point out cause voids due to the plating.

Voids found

Mar 2, 2006 | Voids found Hi, We found voids on BGA. Understand IPC stated as long as not more than 25% should be fine. So, is there any standard stated how many voids in BGA can be allow. Appreciate your help......

Solder Paste Voids

Nov 23, 2005 | Solder Paste Voids Search the fine SMTnet Archives for background on BGA void, while you're waiting for others to respond

Solder Paste Voids

Nov 23, 2005 | Solder Paste Voids We are using AIM WS300 solder paste and are experiencing excessive voiding on our BGAs. We have exhausted reflow profile alternatives and just can't beat the voids. Has anyone had success with this paste on BGAs? If so how?

Voiding under BGA's

May 10, 2005 | Voiding under BGA's Dr Lee at Indium has written extensively on voiding, Check their site for papers.

Voiding under BGA's

May 8, 2005 | Voiding under BGA's We are continuing to struggle with voids under BGA's. Our problem are not consistent. some CCA's are perfect but others have pin hole sized voids. Does anyone have any feedback on Indium 92j and how it performs for bga's?

BGA Specifications for IPC Class

Feb 2, 2005 | Based on X-ray imaging, IPC-7095 standard specifies three categories for void size for BGA solder joints. These categories are based on the percentage of joint cross sectional area occupied by the voided area. Class III Small: Void area is LT 9% Class II Medium: Void area GT 9% but LT 20.25% Class I Large: Void area GT 20.25% but LT 36% This standard does not specify a category for voids GT 36% and assumes that is beyond acceptable limits of most products. Class III product would be for highest reliability with the smallest allowable void area.

LSP profile

Jun 7, 2004 | First, voiding is a process indicator. Next, as you say, the profile is a significant contributor to void formation. Finally, when considering the "material factors" that drive void formation, solder paste formulation is the most critical. Discussing voids is one THE most favorite topics here

Large Voids with Via in Pad

Apr 13, 2004 | Large Voids with Via in Pad Now, that's different. We misunderstood the problem from your original descrtiption. We thought the voids were showing at the via in the pad. Now, we understand the voids appear to be in the solder balls. Suggestions are: * Search the SMTnet Archives. * Get some of the papers published by Dr . Lee at Indium Corp. He has conducted a number of investigations concerning solder joint voiding and BGA components. * Following from this previous comment, recognize that solder paste composition is a major contributor to BGA voiding. * That voids disappear when you rework them with hot air, may

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