©hdp user group international, inc. proprietary 1 bmps (board-mounted power supply) modules...

©HDP User Group International, Inc. Proprietary

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BMPS (Board-Mounted Power Supply) ModulesDefinition Stage Project

Update May 18, 2011 Shenzhen, PRC


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Overview of BMPS ProjectsBMPS Project Overview

• Board Mount Power Supply (BMPS) Application Guideline, version 1.0 (2007)– The first edition was released 3 years ago. It was a ”best practices

paper” based on the known technology at that time.

• Board Mount Power Supply (BMPS) Application Guideline, version 2.0 (2010)– The second edition is complete and published. It updates the first

edition with current best practices.

• Board Mount Power Supply (BMPS) Modules– This project will focus on features, practices and processes on and

surrounding BMPS modules with respect to their assembly to PWBs. – The results of this project may be inserted in the BMPS Guideline

third edition.


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Objectives

The objective of the project is to:

• Identify the key design / manufacturability issues and opportunities with a focus on assembly

• Demonstrate the feasibility, accessibility, and reliability of select module-PWB interconnect features.

• Issue guidelines on PWB layout for BMPS that will aid in assy.

– Pad configurations, etc.

• Issue guidelines for automated handling of BMPS– Pick and place nozzles, grippers etc.Issue guidelines for

automated handling of BMPS– Pick and place nozzles, grippers etc.


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Opportunity / Challenges

Technology changes and manufacturingexpectations have uncovered issues regarding theuse of modern high-current BMPS modules

1. Lead-free soldering• Hole-fill on critical connections is routinely below targets.• Manage critical temperatures across different components • Energy Efficiency is an industry Priority

2. Surface Mount BMPS Modules• Opportunity to eliminate wave solder process

3. Reliability of select “QFN” and CSP BGA packages/attaches

4. Handling Automation• Desire to eliminate hand loading of BMPS modules• Desire to obviate hand soldering and touch-up

5. Currents are increasing• Different interconnect scheme needed• Interconnect scheme is at root of other issues of greatest

interest.

- Power brick pin-thru hole-fill is routinely below target in “real life”.

- IPC-A-610DC Telecom Addendum 7.5.5.1 reducing PTH solder fill to minimum pin-wetted length within barrel of 0.047”

- This “helps” – in terms of pure workmanship standards acceptability - but is a small, incremental change.

-This does not change our motivation for hole-fill optimization.©HDP User Group International, Inc.

Proprietary5

Brick Hole-Fill

Brick Hole-Fill


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Example: hole-fill below class2 minimumOn “real product” assembly qualification.

Note: good thermal relief, OK pin-hole clearance,Poor(?) thermal inertia(no gnd plane annular rings)

Fill

Fill

PCB Thickness

Brick Hole-Fill


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Example: hole-fill below class2 minimumOn “real product” assembly qualification.

Note: good thermal relief, good pin-hole clearance,Poor(?) thermal inertia(no gnd plane annular rings)

Brick Hole-Fill

• Intent of BMPS Hole-Fill focus is to complement/supplement HDP Cu-Dissolution / Hole-Fill Project.

• Comparison of BMPS feature complements to Cu Erosion

• Work from / confirm / extend findings of other hole-fill work.

Cu-Dissolution vs. BMPSCu-Dissolution vs. BMPSCu-Dissolution/Hole-Fill• Optimize hole-fill vs. Cu-dissolution

• Measures:

– Hole-fill

– Cu Thickness Remaining

– Cu Dissolution Rate

• Component Types:

– DIMM sockets

– Capacitors

– ½ Brick Power Module

• 0.130” thick board

– 12 layers: 4x 1oz + 8x 2oz

• Variables

– Solder Alloy

– Wave Type

– Solder Temp

– Contact Time

– Plane connections / Thermal Relief

– Pin to hole clearance

BMPS

© HDP User Group International, Inc.

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• Optimize BMPS interconnect to/through PCB

• Measures:

– PTH Hole-fill

– SMD Thermal/Shock/Vibe Reliability

– Functional (Interconnect)Performance

• Component Types:

– PTH ½ Brick Power Module

– SMD ½ Brick Power Module

– SMD Large LGA Power Module

• 0.140 → 0.180 thick board desired

• 12 layers: 4x 1oz + 8x 2oz

• Variables

– PTH Gas-vent / No Gas-vent

– PTH Lead- length

– PTH thermal relief

– SMD interconnect type

– SMD footprint

– Via configurations

Pin-to-Hole Clearance vs FillPin-to-Hole Clearance vs FillHolistic ViewHolistic View


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Courtesy of Celestica, Thilo Sack

Thermal Relief & Other FactorsThermal Relief & Other Factors


11Courtesy of Celestica, Thilo Sack

Thermal Relief & Other FactorsThermal Relief & Other Factors


12Courtesy of Celestica, Thilo Sack

Anomaly: “Entry effect”(leading position on pcb w.r.t. reflow)superceding thermal relief as fill driver(inhibitor)

Fill generally following thermal relief.

CURRENT DENSITY – POWER PLANE - .083” BRICK PIN HOLE W/ 4 SPOKE - 2OZ PLANE - DISTRIBUTED VIA TO TOP&BOTTOM - 100 AMP ~POINT LOAD

BMPS PTHBMPS PTH

CURRENT DENSITY - TOP&BTM - .083” BRICK PIN HOLE - 2OZ PLANE - DISTRIBUTED VIA TO TOP&BTM - 100 AMP ~POINT LOAD

BMPS PTH BMPS PTH

BMPS PTHBMPS PTH

• Fill: Gas Venting vs No Gas Venting


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Woosh

!

BMPS PTHBMPS PTH• Fill vs Thermal Relief Variations


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Plane Disconnect

Spoke Reduction

Spoke Narrowing

Radial/Distributed Via

Targeted fo

r DOE

Targeted fo

r DOE

BMPS PTHBMPS PTH


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- Fill vs Lead Protrusion


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- PTH(Pin-Through-Hole) power bricks are “the” remaining impediment to the elimination of wave solder process.

- True for many assemblies. True for enough sectors of product to pursue aggressively for the sake of process elimination; cost-reduction, manufacturing lead-time, simplicity.

- PTH power connection is familiar, feels robust, well characterized. However, it is a mfg process weak point.

- SMD solutions are on the market, but limited.

-Simple conversions have been applied.

SMT BMPS

Brick SMT Attach VariantsBrick SMT Attach Variants


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Pedestal Leg w/ Ball

Pure Post

LGA

Brick SMT Attach VariantsBrick SMT Attach Variants


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PTH – NO VENT

PTH – WITH VENT

SMT - PURE POST

PTH – LONG, WITH VENT

SMT - PEDESTAL&BALL

BMPS BMPS


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- BMPS DOE

Test Vehicle Details - NominalTest Vehicle Details - Nominal

• Bricks – 30A or greater

• 0.140 - 0.180” Thick

• 12 Layer w/ 2oz & 1oz

• ENIG or ENIPIG Finish

• Larger PCA

• Multiple SMT sites

• Multiple PTH sites

• Dual PTH / SMT site

• SAC305


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Test Vehicle Details - NominalTest Vehicle Details - Nominal

• Assembly

• Rework(Multiple)

• Shock & Vibe

• ATC

• Xray

• X-section

• Dye & Pry

• Electrical Performance


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Test Vehicle ResourcingTest Vehicle Resourcing

• Brick PTH Vented - $ Re-quoting to Emerson

• Brick PTH Un-Vented - $ Re-quoting to Emerson

• Brick SMD Pedestal+Ball - $ Re-quoting to Emerson

• Brick SMD Pure Post - $ Re-quoting to Emerson

• Brick SMD LGA - $ Re-quoting to Emerson

• Design - Juniper Networks

• PCB - Meadville

• Assembly - ?

• Test - ?


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February 2011Suggested Next Steps

1. Window until May Shenzen Meeting to gather new user/supplier participant

input.

2. Complete modeling / design / tape out the test vehicle.

3. Complete resourcing the Test Vehicle

4. Build / Test / Results


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Target Schedule

Project Task When Complete Actual

Project start in definition stage 01/03/09 Date/Month/YY

Project start in implementation stage 05/18/11 Date/Month/YY

Collect knowledge and experience of existing solutions

Ongoing Date/Month/YY

Define a preferred solution, experimental work, if needed etc

05/18/11 Date/Month/YY

Issue a project report 09/07/11 Date/Month/YY

Assemble information for the BMPS Guideline 10/07/11 Date/Month/YY


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Project Participants

System Integrators• Juniper Networks , Leif Hutchinson, Project leader• Tekelec, Tony Cosentino• Oracle(Sun), Livia Hu, Michael Freda • Alcatel, Joe Smetana • IBM, Jim Wilcox • (Ericsson – Joining Soon?)• (Huawei – Joining Soon ?)

Suppliers• Emerson, KK Chin• TDK/Innoveta Randy Heinrich• Nihon Superior Keith Howell• (Ericsson – Joining Soon ?)

Facilitator• HDP User Group Staff, Jack Fisher

End – Thanks!

End.

Thanks !

©hdp user group international, inc. proprietary 1 bmps (board-mounted power supply) modules...

Documents

bmps guideline

intent of bmps hole

brick hole

surrounding bmps modules

hdp user group international

good pinhole clearance

leadfree soldering hole

ok pinhole clearance