N2 would be easyier, large volume vacuum chamber is not practical.
However, I think mechanical cutting is more practical since edge geometry and finish of Laser cut composites is poor.
Regardsn katzko
C.B. Katzko
by Blackberry
----- Original Message -----
From: NG ENG GUAN [[log in to unmask]]
Sent: 06/20/2008 09:37 AM ZE8
To: [log in to unmask]
Subject: Re: [TGA] 有关激光分板的可靠性问题
Hi Renie,
How about perform the laser cutting under a vacuum condition ? Perhaps this
could reduce the Carbonization effect at the cutting edge?
Best regards
EG
From: TGAsia [mailto:[log in to unmask]] On Behalf Of Renie Zhao
Sent: 20 June 2008 09:00
To: [log in to unmask]
Subject: Re: [TGA] 有关激光分板的可靠性问题
Thanks for all of you good feedback!
Previous we tried to use the CO2 laser (10.6 um wavelength) to do the PCBA
cutting, and find there is some carbonization, which can not meet IPC
requirement. Currently we still use the Router or Punch to do the cutting
Otherwise, I heard from some laser vendor that maybe 9.4um wavelength will
be better for PCBA cutting, and has maybe has little carbonization. But
currently there is little this wavelength CO2 laser in China. Do you have
some understanding about 9.4 wave length CO2 laser for PCB/PCBA cutting?
Thanks
Best regards
Renie Zhao (赵艳)
Phone: +86-13543085801
Email: [log in to unmask]
_____
From: TGAsia [mailto:[log in to unmask]] On Behalf Of Chris Katzko
Sent: Friday, June 20, 2008 8:00 AM
To: [log in to unmask]
Subject: Re: [TGA] 有关激光分板的可靠性问题
Generally, the effective depth of cutting glass reinforced materials with
CO2 Laser will be limited to a certain depth per pulse requiring multiuple
pulses as thickness increases, makling the process slow and expensive. For
bare PCB fabrication routing or punching will be more cost-effective. For
singulating PCBA, routing or sawimg can be used but is dusty, a cleaner
process may be water jet cutting (Flow Systems).
If you are trying to cut flexible and rigid materials with the same CO2
laser (for example Rigid-Flex) I suggest you experiment with multiple pass
cutting of the rigid material too avoid over concentrating heat.
Keep in mind the glass fiber reinforcement has two negative effects:
a) low adsorption of CO2 which creates heat
b) diffraction of the Laser beam and loss of cohefrency
Therefore a CO2 Laser with high peak power and short duration will work best
and by making multiple passes the material has a chance to cool to avoid
burning.
A "Top Hat" beam will work better than a raw Gaussian beam so if your Laser
has a beam shaper I suggest to flatten the center and clip the sides with a
small aperature to obtain the highest peak power and shortest duration.
As material thickness and number of glass reinforcement plys increase so
will the difficulty of cutting and you may find the amount of edge tapering
unacceptable. That is why I suggest mechanical cutting as a simpler and
better method. However, I've successfully cut FR-4 and BT up to about 0.5mm
with accedptable results and no charring (discoloration).
Good luck + Regards,
Katzko
C.B. Katzko
by Blackberry
_____
----- Original Message -----
From: NG ENG GUAN [[log in to unmask]]
Sent: 06/19/2008 02:12 PM ZE8
To: [log in to unmask]
Subject: Re: [TGA] 有关激光分板的可靠性问题
nk=blue>
So? Do you have any solution to overcome the carbonized residue on the edge
problem ??
From: TGAsia [mailto:[log in to unmask]] On Behalf Of Joseph Ho
Sent: 19 June 2008 13:58
To: [log in to unmask]
Subject: Re: [TGA] 有关激光分板的可靠性问题
Dear all,
Use laser to cut the outline is possible and can be applied in Flexible PCB
in sample build, our FPCB is thickness and no fiber glass.
However, for rigid PCB, the board thickness is the great concern as the
resin and fiber glass need large energy to cut.
Besides, burn the outline may have carbonized residue on the edge.
With Best Regards
Joseph Ho
Senior QA Manager, B2F
“ Creating value that increases customer competitiveness”
_____
From: TGAsia [mailto:[log in to unmask]] On Behalf Of FP Deng
Sent: Wednesday, June 18, 2008 3:52 PM
To: [log in to unmask]
Subject: Re: [TGA] 有关激光分板的可靠性问题
这是个很好的LEAN project,用激光切割机分板还是切实可行的,它的影响只是外观问
题,最重要的的是能够说服你的客户并能够接受........
Regards.
FP Deng
Manufacturing Engineering
Tel: +86-0769-83394581-260 email:[log in to unmask]
www.celestica.com
Solid Partners. Flexible Solutions.
Renie Zhao <[log in to unmask]>
Sent by: TGAsia <[log in to unmask]>
2008-06-18 15:37
Please respond to
Asia Committe Task Group Forum <[log in to unmask]>; Please respond to
Renie Zhao <[log in to unmask]>
To
[log in to unmask]
cc
Subject
Re: [TGA] 有关激光分板的可靠性问题
我们现在用的都是Router 或者使Punching, 但发现夹具成本费非常高，如果用激光自
动 切割的话，可以省掉不同产品的夹具成本， 也可以提高激光机的应用灵活性。
Best regards
Renie Zhao (赵艳)
Phone: +86-13543085801
Email: <mailto:[log in to unmask]> [log in to unmask]
_____
From: NG ENG GUAN [mailto:[log in to unmask]]
Sent: Wednesday, June 18, 2008 3:27 PM
To: 'Asia Committe Task Group Forum'; Renie Zhao
Subject: RE: [TGA] 有关激光分板的可靠性问题
赵艳小姐,
你好. 我觉的因该不行. 关键是,有必要用激光切割机进行分板吗?
From: TGAsia [mailto:[log in to unmask]] On Behalf Of Renie Zhao
Sent: 18 June 2008 15:18
To: [log in to unmask]
Subject: [TGA] 有关激光分板的可靠性问题
Dear All:
为了提高PCBA 的分板效率，我们试图用激光切割机进行分板，但是在分板过程中总是
有碳化现象， 我们也进行了可靠性测试（功能，跌落，温湿循环，热冲击， 功能），
发现即使有轻微碳化现象，也不影响PCBA 的性能。有关此事请教大家下面几个问题：
1. 在IPC 的标准中，用激光进行PCBA的分割，是否允许有轻微碳化现象？
2. 如果不允许，在我们进行了一系列的可靠性 测试之后，如果确认轻微碳化
并不影响其性能，那么有没有可能根据实际更改一下IPC 的标准？
Best regards
Renie Zhao (赵艳)
Phone: +86-13543085801
Email: <mailto:[log in to unmask]> [log in to unmask]
_____
From: TGAsia [mailto:[log in to unmask]] On Behalf Of Leo Zhang
Sent: Tuesday, June 17, 2008 10:52 AM
To: [log in to unmask]
Subject: [TGA] 交流（镀金）
Dear ALL，
请问哪位对镀金（工艺/工序）比较了解，我有一些问题想请教和交流一下，谢谢！
Best Regards
Leo Zhang 张毅博
==========================================
Engineering
SZ Kaifa Mirco Electronics Co., Ltd.
7006#,CaiTian Road,ShenZhen,China.
Direct Line : (86-755) 83032983
Tel : (86-755) 83275000 Ext.36274/33983
Fax : (86-755) 83275514
Mobile :(86)13728767036
Email : [log in to unmask]
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