SMT Printing

Solutions not known

Solutions not known at this time

Solutions need optimization

Current solutions need optimization

Solutions deployed or known

Solutions deployed or known today

Not determined

TBD

ROADMAP TIMEFRAME

TECHNOLOGY ISSUE

TODAY (2024)

3 YEARS (2027)

5 YEARS (2029)

10 YEARS (2034)

ISSUE #1

Stencils to improve print quality of small apertures on mixed component applications

NEED

Stable print to area ratio of 0.6. Ensure high and stable transfer efficiency (>70%) from small aperture printing. Standard Deviation <10%.

Stable print to area ratio of 0.55. No other change.

Stable print to area ratio of 0.5. No other change.

CURRENT TECHNOLOGY STATUS

Solutions Deployed or Known Today

Solutions Need Optimization

Technology Status Not Determined

GAP

Maintaining keep-out space compliance for step-stencil designs.

Maintaining keep-out space compliance for step-stencil designs. Stencil manufacturing quality and solder paste compatibility factors due to stricter area ratio requirement.

Maintaining keep-out space compliance for step-stencil designs. Stencil manufacturing quality and solder paste compatibility factors due to stricter area ratio requirement. Printing machine performance factors due to stricter area ratio requirement.

CHALLENGE

Designers are making components and inter-spacings smaller, reducing step stencil keep-out areas.

• Designers are making components and inter-spacings smaller, reducing step stencil keep-out areas.

• Improving stencil manufacturing tolerances.  Use of higher cost finer powder solder pastes.

• Designers are making components and inter-spacings smaller, reducing step stencil keep-out areas.

• Improving stencil manufacturing tolerances.  Use of higher cost finer powder solder pastes.

• Printing machine alignment and stencil gasket control.

ISSUE #2

Printing the full real estate of a circuit board

NEED

Print to the extreme outer edges of the board edge or as close as possible. Print keep-out distance from board edge is at least 10 mm when using traditional top clamping hardware in printing machine.

Print keep-out distance from board edge is at least 5 mm when using traditional top clamping hardware.

CURRENT TECHNOLOGY STATUS

Solutions Deployed or Known Today

Solutions Deployed or Known Today

GAP

None

CHALLENGE

Maintain flush stencil contact to the full area of the board including its extremities.

ISSUE #3

Enabling low area ratio printing through advancements in laser cut stencil fabrication

NEED

At area ratio of 0.6 achieve volume print transfer efficiency >  70% and volume standard deviation < 10%.

At area ratio of 0.55 achieve volume print transfer efficiency > 70% and volume standard deviation < 10%.

At area ratio of 0.5 achieve volume print transfer efficiency > 70% and volume standard deviation < 10%.

CURRENT TECHNOLOGY STATUS

Solutions Deployed or Known Today

Solutions Need Optimization

GAP

None

Shrinking component dimensions drive use of smaller apertures and tighter interspacing.

CHALLENGES

• Maintaining uniform aperture profile at small dimensions.

• Stencil aperture opening differences.

• Stencil supplier capability differences to meet requirements for stricter control of aperture cut dimensions.

• Improving the application and adhesion of nano-coatings to aperture walls. This may require new foil material, understanding the performance and industry definition of fine-grained stainless-steel stencils, novel coatings, and improvements to laser cutting process equipment.

ISSUE #4

Paste homogeneity in enclosed pump-head printing system

NEED

Preserve and maintain proper mix ratio of paste particles to flux to accomplish stable printing.

CURRENT TECHNOLOGY STATUS

Solutions Need Optimization

GAPS

• Static type pump-head systems exist that are not designed with active paste mixing function.

• Use of enclosed pump-head printing systems is declining as industry shifts more towards conventional squeegee blade printing for all applications.

• Advanced pump-head systems are available with dynamic paste mixing feature.

• Equipment suppliers are not implementing further developments.

Expectation that enclosed pump-head printing will be rarely used anymore.

CHALLENGES

Difficulty in mixing paste fully in pump-head. Active paste mix systems are complicated to clean and maintain by user. Applying too much pressure to the paste.

Difficult for maintenance for legacy systems.

ISSUE #5

Preventing under stencil wipe cleaning liquid from wetting top side of stencil

NEED

Printing machine under stencil wiping system should apply stencil cleaning liquid to wet only stencil bottom side and inside aperture walls.  (Topside stencil wetting risks cleaning liquid contact with solder paste and potential introduction of process damaging contaminants.)

CURRENT TECHNOLOGY STATUS

Solutions Need Optimization

GAP

Cleaning liquid contamination on stencil topside is not detectable.  There is a lack of cleaning liquid dosing feedback.

CHALLENGE

Development and  implementation of sensors / systems to assist detecting excess solvent seeping through apertures that contaminates the stencil topside during an under-stencil wipe process. (Need to understand interaction of fabric roll with solvent and parameters.)

ISSUE #6:

Maintenance intervals for printing equipment

NEED

Need to increase the maintenance intervals (Predictive maintenance is based on the number of boards printed). The printing machine should indicate when maintenance is required based on the number of boards printed.

CURRENT TECHNOLOGY STATUS

Solutions Need Optimization

The practice of manual maintenance record keeping and “fix it when it breaks” approach is still prevalent. Based on printing equipment recommendations, weekly, monthly, six monthly checks.

GAPS

• Lack of automatic maintenance notification / predictive maintenance. 

• Machine design for serviceability does not exist. 

• Maintenance is typically based on calendar time durations not based on the number of boards printed.

• Lack of sensors for better self-diagnostics of machine.

• Lack of improved traceability of squeegee blade wear for example.

CHALLENGES

• Challenges for developing and implementing on-board service assistance tools.

• Few printers built with new sensors to detect system wear / failure.

• Integrating SPI and other tools to connect and communicate with printer is difficult.

ISSUE #7:

Printing extra-large boards (24 inch x 1.5 meter (591 inch) in length) (600 (24 inch) x 800 mm (32 inch) board for network) (LED display boards or back-panel boards: thin or thick boards and heavy boards)

NEED

Good board design (understand spacing between large and small component and fine pitch components). Good printing.

CURRENT TECHNOLOGY STATUS

Solutions Need Optimization

24 inch width is okay to do but 1.5  meter (59.1  inch) length is a challenge. Certain applications can do a stitching process- printing a section/half of the board and then print the remainder. (Not common or convenient.) This may restrict the length of the backplane/complex board to manufacture.

GAP

• Lack of the following:

• Printing equipment to print boards with this length.

• Stencil inability to cope with board stretch.

• Printer handling boards with larger mass (backplane boards) and general handling.

• For large backplane boards, small volumes do not justify large investments in printing equipment.

CHALLENGE

Shrinkage and warpage issues for large boards with fine pitch components. Board stretch with challenges of aligning global and local fiducials.

ISSUE #8

Changeover Automation

NEED

Reduce manual processes involved with printing equipment setup.

CURRENT TECHNOLOGY STATUS

Solutions Need Optimization

Automatic tooling pin support placement systems are now available.  Automatic paste dispense from cartridges widely available.  Automatic paste dispense from jar containers available.

GAP

Lack of automated installation for dedicated tooling. Dedicated tooling requires manual installation.  (Automatic squeegee and stencil exchange system working prototypes have been demonstrated in controlled settings.)

CHALLENGE

New and evolving automation features may not be retrofittable to legacy printing machines, requiring investment in new equipment.  Automation option cost versus value.

ISSUE #9

Automatic Process Control In Production

NEED

Reduce manual processes involved with printing equipment operation during production.

CURRENT TECHNOLOGY STATUS

Solutions Need Optimization

• Closed loop squeegee pressure control capability is well established and automatic squeegee pressure calibration capability is selectively available. 

• Solder paste inspection machine feedback to printing machine permits automatic alignment offset adjustment and automatic under stencil cleaning.

• Some advanced solder paste inspection feedback systems permit automatic print speed and squeegee pressure optimization.

• Novel systems exist to automatically remove solder paste residue from squeegee blades inside the printer.

GAP

• Vast majority of printing machines do not self-check vision alignment calibration.

• Topside stencil cleaning is not available.

• Some implementation of IPC CFX standard (or other unique protocols) required for printer to SPI machine communication (for  new equipment only).

CHALLENGE

Software, networking for printer to SPI machine communication. Automation cost vs. value.

Automation cost vs. value

ISSUE #10

Process Traceability Automation

NEED

Reduce manual data entry by automatically recording details of hardware (machine, tooling, stencil), materials (solder paste, substrate), and equipment settings (process equipment recipe, operating environment) used in a stencil printing machine process job.

CURRENT TECHNOLOGY STATUS

Solutions Need Optimization

Semi-automatic tracking using manual label readers is common. Some laser marking of boards.

GAP

Lack of integration with warehouse / enterprise/ factory level.

CHALLENGES

• Radio-frequency ID (RFID) and barcode labels are unreliable (unreadable).

• Location of fixed position RFID and barcode readers.

• Automation cost vs. value. Data management.

ISSUE #11

Replenishment of under-stencil cleaner fabric

NEED

Reduce printing machine downtime due to unscheduled manual intervention by predictive maintenance and automating consumable replenishment processes.

CURRENT TECHNOLOGY STATUS

Solutions Need Optimization

Under-stencil cleaner fabric roll change requires printing machine cycle stop for manual replacement. 

GAP

Uninterrupted printing during under stencil cleaner fabric roll change is currently unsupported.  (New under-stencil cleaner system designs permit more productivity enabled by larger fabric roll size.)

CHALLENGES

• Automation cost vs. value.

• Managing consecutive printing jobs that may require unique under stencil cleaning consumables. 

• Continue uninterrupted defect free print process during a consumable replenishment alarm.

ISSUE #12

Replenishment of under-stencil cleaner fluid

NEED

Reduce printing machine downtime due to unscheduled manual intervention by using predictive maintenance and automating consumable replenishment processes.

CURRENT TECHNOLOGY STATUS

Solutions Need Optimization

Under-stencil cleaner fluid change requires manual re-filling.

GAP

Lack of new under-stencil cleaner system designs that will permit more productivity- enabled larger capacity front-side-accessible solvent reservoirs

CHALLENGES

• Automation cost vs. value.

• Managing consecutive printing jobs that may require unique under stencil cleaning consumables. 

• Continue uninterrupted defect-free print process during a consumable replenishment alarm.

ISSUE #13

Application and Replenishment of Solder Paste

NEED

Reduce printing machine downtime due to unscheduled manual intervention by using predictive maintenance and automating consumable replenishment processes.

CURRENT TECHNOLOGY STATUS

Solutions Need Optimization

There is some availability of automatic solder paste replenishment using programmable paste cartridge or jar dispense that is based on print cycle count or paste bead size sensor feedback option. Limited prediction of the replenishment process to reduce print downtime.

GAP

Solder paste replenishment for jars. (This is related to non-standard jar diameter and height.) 

CHALLENGES

• Solder paste replenishment for –jars- hardware has not been designed for this automation. 

• Automation cost versus value. 

• Development of predictive paste replenishment in combination with stencil cleaning needs to reduce printer downtime 

Automation cost versus value. 

ISSUE #14

Step stencil print quality

NEED

Development of squeegee blade technology and materials capable of good contact on stencil closer to the step wall edge to enable printing of apertures close to the step up/down boundary.

CURRENT TECHNOLOGY STATUS

Slotted squeegee and soft squeegees are available. Slotted squeegees will not work with several step-up locations. Soft squeegees wear out quickly and can scoop paste with large apertures(less paste printed). Standard says X (Keep-out distance = step depth x 36. 1  mil step up = 36 mils keep-out). Currently industry can use down to 1 mil step up =  24 mils). This capability requires a thinner squeegee to achieve this)  IPC standard needs review and update on this issue

Keep-out distance = step depth x 36. 1 mil step up = 36 mils keep-out. Industry can use down to 1 mil step up =  18 mils). This capability requires a thinner squeegee to achieve this.  IPC standard needs review and update on this issue

Solutions Need Optimization

GAP

Inadequacy of standard blade to wipe paste close to the step stencil wall.  (Gap between squeegee suppliers in terms of differences in squeegee blade thickness supplied that would affect keep out distances)

CHALLENGE

Having a more compliant metal type squeegee blade that provides durability of a standard rigid blade. This is a squeegee blade technology and material development issue not a step stencil development issue.

2

TRL: 1 to 4

Levels involving research

6

TRL: 5 to 7

Levels involving development

9

TRL: 8 to 9

Levels involving deployment

EXPECTED TRL LEVEL*

TECHNOLOGY ISSUE

POTENTIAL SOLUTIONS

TODAY

(2024)

3
YEARS

(2027)

5
YEARS

(2029)

10
YEARS (2034)

ISSUE #1

Stencils to improve print quality of small apertures on mixed component applications

Stencil frame structural tolerances, straightness, and rigidity accommodating print area ratio ³ 0.6.

9

9

9

9

Stencil frame structural tolerances, straightness, and rigidity accommodating print area ratio ³ 0.55.

8

8

9

9

Stencil frame structural tolerances, straightness, and rigidity accommodating print area ratio ³ 0.5.

7

8

9

9

Nano-coating accommodating print area ratio ³ 0.6.

9

9

9

9

Nano-coating accommodating print area ratio ³ 0.55.

8

8

9

9

Nano-coating accommodating print area ratio ³ 0.5.

7

8

9

9

For printing technical issue # 1, there will be stencil frame coplanarity and stencil foil dimension and aperture wall surface roughness and nano-coating challenges after 3 years, based on AR (area ratios) of 0.55 and after 10 years based on AR of 0.5.

ISSUE #2

Printing the full extents of a circuit board

Top pinch clamp to accommodate print area ratio ³ 0.6 for apertures located ³ 10 mm from clamped edge of board.

8

9

9

9

Top pinch clamp to accommodate print area ratio ³ 0.55 for apertures located ³ 10 mm from clamped edge of board.

7

8

9

9

Top pinch clamp to accommodate print area ratio ³ 0.5 for apertures located ³ 10 mm from clamped edge of board.

6

6

7

8

Top pinch clamp to accommodate print area ratio ³ 0.6 for apertures located ³ 5 mm from clamped edge of board.

6

7

8

9

Top pinch clamp to accommodate print area ratio ³ 0.55 for apertures located ³ 5mm from clamped edge of board.

5

6

7

8

Top pinch clamp to accommodate print area ratio ³ 0.5 for apertures located ³ 5 mm from clamped edge of board.

4

5

6

7

Foil-less and snugger clamp to accommodate print area ratio ³ 0.6 for apertures located ³ 0.5 mm from clamped edge of board.

8

9

9

9

Foil-less and snugger clamp to accommodate print area ratio ³ 0.55 for apertures located ³ 0.5 mm from clamped edge of board.

7

8

8

9

Foil-less and snugger clamp to accommodate print area ratio ³ 0.5 for apertures located ³ 0.5 mm from clamped edge of board.

6

6

7

8

For printing technical issue # 2, there will be development of top clamping after five years due to needs for 5 mm distance from the board edge from a 10 mm distance from the board edge.

ISSUE #3

Enabling low area ratio printing through advancements in laser cut stencil fabrication

Improved laser technology, cutting manufacturing tolerances, and quality to accommodate print area ratio ³ 0.6.

9

9

9

9

Improved laser technology, cutting manufacturing tolerances, and quality to accommodate print area ratio ³ 0.55.

8

8

9

9

Improved laser technology, cutting manufacturing tolerances, and quality to accommodate print area ratio ³ 0.5.

7

8

9

9

For printing technical issue # 3, there will be laser cutting stencil challenges after three years based on ARs of 0.55 and after 10 years based on ARs of 0.5.

ISSUE #4

Paste homogeneity in enclosed pump-head printing system

Mixing, stirring, other methods to circulate paste material inside head.

8

8

8

8

Sensors and monitoring of paste condition inside head.

2

3

4

6

For printing technical issue # 4, there will be no investment to innovate pump-head technology to increase full mixing of paste based on lack of industry demand. There will continue to be support for existing equipment with this technology used in the field.

ISSUE #5

Preventing under stencil wipe cleaning liquid from wetting top side of stencil

Liquid consumption monitoring.

8

8

9

9

Liquid over-dosage detection.

5

6

7

8

Liquid dosage optimization.

4

5

6

8

ISSUE #6

Predictive maintenance for printing equipment

Automatic maintenance notifications / predictive maintenance feature.

6

7

8

8

Under-stencil cleaning consumable demand prediction per product.

6

7

7

8

Implementation of smart sensors or feedback devices enabling active monitoring of critical equipment functions.

4

5

6

8

Automatic vision calibration and verification.

4

5

6

8

ISSUE #7

Printing extra-large boards > 20 inches (508 mm)

Multi-step stitch enabled printing machine process capability.

5

6

6

7

Large substrate size capacity printing machine.

8

8

8

9

ISSUE #8

Changeover automation

Programmable automatic solder paste dispense from cartridge.

8

9

9

9

Automatic solder paste cartridge exchange.

5

6

7

8

Programmable automatic solder paste dispense from jar.

7

8

8

8

Automatic solder paste jar exchange.

4

5

6

7

Programmable automatic tooling pin exchange & positioning system.

7

8

8

9

Automatic print material exchange system.

7

8

8

9

Automatic stencil exchange system.

6

7

8

8

Automatic squeegee exchange system.

5

6

7

8

Automatic under stencil cleaner fabric roll exchange.

4

5

6

7

ISSUE #9

Automatic print process control in production

Solder paste bead size monitoring, coupled to automatic paste replenishment.

8

8

9

9

Solder paste inspection machine closed loop feedback to printing machine for automatic adjustments to optimize alignment offset and under stencil cleaning.

7

8

8

8

Solder paste inspection machine closed loop feedback to printing machine for automatic adjustments to optimize print process parameters.

6

7

8

8

Solder paste inspection machine closed loop feedback to printing machine for guided stencil aperture inspection.

6

6

7

8

Solder paste condition fitness for use monitoring.

6

6

7

8

Automatic coplanarity adjustment per product.

5

6

7

8

Smart squeegee dynamic controls (angle, pressure, speed).

4

5

6

7

ISSUE #10

Process traceability automation

Automatic record keeping of hardware (machine, tooling, stencil), materials (solder paste, substrate), and critical printing equipment settings.

6

7

8

8

ISSUE #11

Under-stencil cleaner fabric replenishment

Increased under stencil fabric roll size capacity to reduce refill frequency.

7

8

8

9

Automatic under stencil cleaner fabric roll exchange.

4

5

6

7

Fabric roll free under stencil cleaner.

1

2

3

5

ISSUE #12

Under-stencil cleaner fluid replenishment

Front positioned large capacity fluid filling station accessible and usable during production.

8

8

9

9

Dosage sensors to improve fluid use and replacement.

5

6

7

8

Pour-less fluid refill method.

4

5

6

7

ISSUE #13

Solder paste management on stencil

Automatic solder paste collection from loaded product stencil and transfer back to same or new stencil.

7

8

8

9

Standardize paste jar container to a common form compatible with automatic jar dispense hardware configured for stencil printing machines.

4

5

6

7

ISSUE #14

Step stencil print quality

Slotted squeegee process expected to accommodate 24 mil (0.60 mm) keep-out spacing at 1 mil (0.025 mm) step size.

7

8

8

9

Slotted squeegee process expected to accommodate 18 mil (0.46 mm) keep-out spacing at 1 mil (0.025 mm) step size.

6

7

8

8

Soft compliant squeegee blade materials.

8

9

9

9

Compliant and resiliently sharp squeegee blade material.

4

5

6

7

Stencil technology improvements.

6

7

8

8

For printing technical issue # 14, the capability of slotted squeegees will be challenged as keep-out distances reduce over time. Soft squeegees are not deployed as industry does not want to use them as there would be increased wear out from their use.