Solder Ball Attach WB-300 - Wagenbrett · ISIT Fraunhofer Institut Siliziumtechnologie Device...

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www.wagenbrett.de

Fraunhofer InstitutSiliziumtechnologie

Device qualification at ISITDevice qualification at ISIT

Solder Ball Attach WB-300

www.wagenbrett.de

Device qualification at ISITDevice qualification at ISIT

Solder Ball Attach WB-300

www.wagenbrett.de

• unlimited umber of balls

• standard SMD stencil tooling

• throughput ca. 20 substrates / h

• ball diameter : 760 – 250 µm

• series production

Vakuum Feeding Gravity Feeding

• number of balls limited

• tooling expensive, long supplytime

• throughput ca. 4 substrates / h

• ball diameter : 760 – 300 µm

• prototyping

PlacementAlignment

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Wagenbrett WBWagenbrett WB--300300• application of solder spheres300 µm - 760 µm Ø

• wafer 4“- 300 mm, PCB

• qualified for WLP-CSPproduction at Fraunhofer ISIT

• 52.000 solder balls per 6“-wafer,500 µm Pitch, 300 µm Ø

• throughput: typ. 21 wafer/h

• Yield: 99,994 %

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Wagenbrett WBWagenbrett WB--300300• ball attach after UBM and grinding

• ball fixation with stencil printed tacky flux

• positioned balls are tolerant to waferhandling

• rework is possible after flux print and ball attach

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Wagenbrett WBWagenbrett WB--300300• “Gravity Feeding“ works with excessive

ball numbers

• multiple balling runs with the same ballsis uncritical

• 3 point adjust is very effective for fastsubstrate exchange

• surplus balls run off the stencil by tilting

• stencil cleaning is usually not requiredduring the processing!

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Wagenbrett WBWagenbrett WB--300300

monitor

X,Y, Θ adjust

cameras

stencil

machine control

cross hairs generator (optional)

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semi automatic machine conceptsemi automatic machine concept

• simplified process control concept for ease of operation

• robust substrate vacuum fixation

• controlled roll off of surplus solder balls without operatorintervention

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substrate preadjustsubstrate preadjust

exchangable vacuum plate cavity for

vacuum tweezer

universal fixation of different substrate diameters up to 300 mm

preadjust with 3 points

customer specific vacuum plates on request

ESD-conform design

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solder ball mangementsolder ball mangement

Surplus balls are removed by stencil tilting!

stencil

wafer flux deposit

solder ball

distance

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solder ball mangementsolder ball mangement

• ESD-conform ball container forsurplus balls

• very low risk of ball defects

• reduced number of manualhandling

• solder ball management workswith SAC lead free alloys, tested with 300 µm Ø, 500 µm Ø

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machine setupmachine setup

• easy machine setupwith precision heightadjust gauge

• available as option

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Experience in balling througput Experience in balling througput WBWB--300 solder ball attach tool300 solder ball attach tool

processing time for ball attach < 3 minutes/wafernew tooling setup < 10 minutesnumber of missing balls in mean: 2 balls per 52000 balls placed, equals 99,994 % yieldquality is nearly independet of operatorlow demand on operator qualificationattached balls can be reworked if necessary

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statistics of missing balls for statistics of missing balls for ball attach with WBball attach with WB--300300

Wafer Nummer

Number of missing balls after reflow

Example of 2 lots á 24 wafers

52000 solder balls per wafer,

6“, 300 µm Ø, pitch 500 µm

99,998 %

99,996 %

99,994 %

99,992 %

99,990 %

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solder ball attach on alternative solder ball attach on alternative substratessubstrates

FR4 substrate silicon die

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application specific modifications application specific modifications WBWB--300300

machine options:ESD-blowercross hair generatorcustom design vacuum platereduction frameprecision height adjust gaugeapplication training at ISIT

Solder Ball Attach WB-300 - Wagenbrett · ISIT Fraunhofer Institut Siliziumtechnologie Device...

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