Why Clean Boards should be a Priority for the SMT Sector Sheila - - PowerPoint PPT Presentation

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Apr 20, 2023 259 likes •479 views

Why Clean Boards should be a Priority for the SMT Sector Sheila Hamilton Teknek Limited Outline 05/03/2019 EEARS 2011 2 What does Teknek do? Teknek manufactures high efficiency contact cleaning systems using proprietary technology for

SLIDE 1

Why Clean Boards should be a Priority for the SMT Sector

Sheila Hamilton

Teknek Limited

SLIDE 2

05/03/2019 EEARS 2011 2

Outline

SLIDE 3

05/03/2019 EEARS 2011 5

What does Teknek do?

Teknek manufactures high efficiency

contact cleaning systems using proprietary technology for removing particles of contamination down to 1 micron from substrates at several stages during the manufacturing process

SLIDE 4

Double Sided Option

Pre-Sheeted Adhesive Roll traps contamination Elastomer cleaning rollers PCB Feed Static elimination Panel conveyor

SLIDE 5

Single Sided Option

Pre-Sheeted Adhesive Roll traps contamination Elastomer cleaning rollers PCB Feed

Static elimination

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Assembly Process Defect Chart

According to data from the Surface Mount Technology Association 74% of defects in PCB manufacturing process are related to solder paste.

[ Source: SMTA 2000 ]

Printing Process Related Defects

SLIDE 7

Board failures

Some typical board failure mechanisms

SLIDE 8

Contamination related issues found by 3D-SPI

Excessive solder paste deposit

Chip Chip Desired amount

f paste

Reason:

Dust and dirt from board manufacture and storage cause poor gasketing from stencil to PCBs

Volume: 205% (Excessive Error)

SLIDE 9

Contamination related issues found by 3D-SPD

Insufficient solder paste deposit

Desired amount of paste

Insufficient paste may lead to parts separation or cracking of the fillet during accelerated life testing. Volume: 35%

Reasons:

Contamination creating blockage of stencil hole, meaning solder paste cannot fill the aperture properly

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Contamination related issues found by 3D-SPI

CSP or BGA After Reflow CSP or BGA

Open Circuit

SLIDE 11

Contamination related issues found by 3D-SPI

Reasons:

Foreign substances are on the PCB’s Too many prints without wiping the stencil

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Conductive contamination analysis using EDX

200µ EDX result = Mg, Al

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Conductive contamination analysis using EDX

EDX result = Mg, Al 200µ

SLIDE 14

Conductive contamination analysis using EDX

100µ EDX result = Mg, Al

SLIDE 15

Conductive contamination analysis using EDX

50µ EDX result = Sn

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Conductive contamination analysis using EDX

EDX result = Cu,Ni 50µ

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Contamination from boards collected

n Adhesive Roll can be

analysed

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PPM Improvement

SLIDE 19

Cleaning = yield improvement = ROI

Koh Young AOI – overall combined supply results

Approx 30% yield improvement

Teknek SMT installed weeks 36 -38

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Yield Improvement

Teknek SMT machine results:

Overall fails fall from an average of 6.66% to 4.6%
an improvement of 31%
Excessive solder faults fall from 1.53% to 0.6%
an improvement of 61%
Bridging falls from an average of 1.13% to 0.43%
an

improvement of 62%

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Benefits of Teknek Contact Cleaning

 Increase Yields  Improves solder joint integrity  Removal of random and variable contamination related defects  Ensure a clean surface for printing and maximise print quality  Ensures better stencil to board gasketing  Reduces tombstoning / rework / rejects  More reliable product  Reduced field returns  Saves time and money