Hi Charles + Ma
The reason changing soldermask is generally undesirable is:
1. May have big cost impact
2. May cause delays since it is a permanent insulating material and may require product requalification.
3. Some OEMs are very picky about cosmetic appreance and strictly standardize the BOM for any PN or all PN.
So I suggest you test other fluxes and tuning the process first since it is more flexible and less time-consuming. Your solder and flux material suppliers may be familliar with the soldermask used and capable to make suggestions if you can identify the type.
Regards
C.B. Katzko
Research + Development
Meadville Group
by Blackberry
----- Original Message -----
From: MAXIN [[log in to unmask]]
Sent: 10/25/2009 05:17 PM ZE8
To: [log in to unmask]
Subject: Re: [TGAsia] Solder Balls
Dear charles,
Would you like to provide the flux model which you are using? There should not be so much solder ball around PTH after wave soldering, unless you are using N2 protection during wave soldering.
You can reduce the solder ball through adjust some raw materials. The most concern is the solder mask (or printing ink) on your PCB. The second one is the flux.
For example, we have several customers which are making PC motherboard and there are many PTHs on their boards, while we can avoid the solder ball problem by adjusting the flux formulation, you know, generally, our customer do not like to ask their PCB suppliers to make certain change (I mean, change the ink for solder mask).
with best regards,
---------------------------------------
MA XIN, Ph.D., CEO
Yik Shing Tat Industrial Co., Ltd.
Website: www.yikst.com
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No.38, Qianjin 2rd Rd., Xixiang
Bao an District, Shen Zhen
518101, P.R. China
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Tel: 86-755-27473328
Fax: 86-755-27473196
Email: [log in to unmask]
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======= 2009-10-24 17:54:27 you write=======
>标准不可能完全清晰化的,你可以拿片PCBA用箭头标识出来那些位置有SOLDER BALL,然后拿在手上晃动,如果还在原地不动的说明是不可移动的,反之就是不移动的
>
>另外你可以看SOLDER BALL的外围是否有被包裹着的迹象,如果有可以拿在手里晃晃,不动的就是不可移动的哇
>
>张美娟
>
>
>
>在2009-10-19，"QA[ShaoHua Wu]" <[log in to unmask]> 写道：
>
>HI all:
> 有沒有什麽方法判斷錫珠是不是可移動的，在此方面好像有一些判斷不清。
> 少華
>-----Original Message-----
>From: TGAsia [mailto:[log in to unmask]]On Behalf Of Brandon Tang
>Sent: Friday, August 21, 2009 3:36 PM
>To:[log in to unmask]
>Subject: Re: [TGAsia] Solder Balls
>
>
>
>Charles
>
>Solid content is very low but per your picture why there were much tacky residues on PCBA ,that’s the reason you are difficult to remove solder balls.
>
>I don’t know the configuration of wave solder in you side , Did you raise preheat temperature by 3-5℃ ,I bet flux vendor can help you solve this problem
>
>Brandon
>
>
>
>From: TGAsia [mailto:[log in to unmask]] On Behalf Of charles.lee
>Sent: 2009年8月21日 11:07
>To:[log in to unmask]
>Subject: Re: [TGAsia] Solder Balls
>
>
>
>Dear Brandon,
>
>
>
>We are using alcohol-based ,no-clean flus which solid content is 2.5+-0.5%,
>
>
>
>Best Regards
>
>Charles Lee
>
>
>
>From: TGAsia [mailto:[log in to unmask]] On Behalf Of Brandon Tang
>Sent: Friday, August 21, 2009 8:04 AM
>To:[log in to unmask]
>Subject: Re: [TGAsia] Solder Balls
>
>
>
>Charles
>
>What flux is used on your PCBA , alcohol-based or water-based ? what’s the solid content of flux? and is there large pad around PTH connector to absorb heat during wave solder ?
>
>Brandon
>
>
>
>From: TGAsia [mailto:[log in to unmask]] On Behalf Of Maker Cheng
>Sent:2009年8月20日 17:58
>To:[log in to unmask]
>Subject: Re: [TGAsia] Solder Balls
>
>
>
>Hi Charles,
>
>Usually, we can’t control the solder appear well during the reflow process or wave solder process. Note: IPC-A-610D has defines the solder ball criteria in Section.5.2.6.1, there are many comment for accept the PCBA with solder ball residue.
>
>
>
>Is wash process or not wash process in your factory? Maybe you can clear out the solder ball with brush and wash process.
>
>
>
>Maker.
>
>From: charles.lee [mailto:[log in to unmask]]
>Sent: Thursday, August 20, 2009 10:10 AM
>To: Cheng, Maker (程仁明 IES); [log in to unmask]
>Subject: RE: [TGAsia] Solder Balls
>
>
>
>Dear Maker,
>
>
>
>It’s definitey difficult to remove so many solder balls via ESD brush since they are too small. Another potential problem is that the sodler balls will become movable balls to hide into pins of ICs after brush.
>
>
>
>Best regards
>
>Charles Lee
>
>
>
>From:[log in to unmask] [mailto:[log in to unmask]]
>Sent: Thursday, August 20, 2009 9:35 AM
>To:[log in to unmask]; [log in to unmask]
>Subject: RE: [TGAsia] Solder Balls
>
>
>
>Hi Charles,
>
>If you can not prevent the solder ball appear in you process well, you can clear out the solder ball with ESD brush in you touch up station after wave solder process to meet IPC standard.
>
>
>
>Maker.
>
>From: TGAsia [mailto:[log in to unmask]] On Behalf Of Charles Lee(SVA)
>Sent: Wednesday, August 19, 2009 11:03 AM
>To:[log in to unmask]
>Subject: [TGAsia] Solder Balls
>
>
>
>Dear All,
>
>
>
>There are a great deal of tiny solder balls appeared in around PTH connector pins after wave soldering (PB Process) , please see the attached pictures.
>
>
>
>Here we would like to seek your helps and suggestions on how to solve the solder ball issues, thanks!
>
>
>
>Best regards
>
>Charles Lee
>
>
>
>
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