Recent Trends of Package Warpage and Measurement Metrologies

(iNEMI Warpage Characterization Project Phase 3)

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Wei Keat Loh1, Ron Kulterman2, Haley Fu3, Masahiro Tsuriya31Intel Technology Sdn. Bhd. Penang, Malaysia

2 Flextronics, Austin, Texas, USA3 iNEMI (International Electronics Manufacturing Initiative), China, Japan

Content• Motivation• Range of packages considered• Dynamic package warpage characteristic

– PoP– PoP Memory– SiP– FCBGA– FCBGA with Lids– PBGA – Summary

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Motivations

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Package Warpage CharacteristicBoard Warpage Characteristic

Board Assembly Parameters

Material selections: solder paste, flux

• Packaging technology is aggressively evolving to meet new user demands and requirements.• Thin and cool device • Energy efficient & Highly integrated SOC/SIP/SOP• High package and board assembly yield

• Dynamic warpage characteristic of electronic package is critical for seamless board assembly. Hence this effort is to understand the kind of dynamic warpage demonstrated in industry.

Package Technology Dynamic Warpage Measurement

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• Generous Donation of Samples from IndustryPackage Type Design Schematic drawing of

package construction

PoP

Overmold TMV® Expose Die TMV®

Bare Die PoP Interposer PoP Pre-stack PoP

package MCeP®

PoP Memories

SiP Overmold Multiple

Chip Package (MCP)

FBGA Overmold single die package

FCBGA with single or multi dies

FCBGA with Lid

Organic and ceramic substrate

PBGA Ranges

• Need more contribution from industry

Package on Package (POP) Warpage Characteristics (Phase 2)

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• POP Package dynamic warpage varies in behavior and form.• Majority are convex at room temperature and transition to concave at high temperature. • The construction of the package and the material used can modulate the dynamic warpage behavior.• All these samples have low warpage within the allowable guideline stipulated in Jedec.

POP Memory Warapge Characteristics

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• POP Memory package dynamic warpage varies in form and behavior.• It is crucial to ensure the POP Memory dynamic warpage (shape) is compatible to POP Bottom Package.• Reducing in package body thickness potentially increases the dynamic warpage range and variability.

FBGA and SiP Package Warpage Characteristics

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Wide variation of dynamic package warpage depending on packaging constructions and materials used.

FCBGA (Single and Multi-Chip) Package Warpage Characteristic

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Simple fundamental: Thinner and larger package gives higher dynamic warpage. Increase demand of ultra thin and cool form factors requires electronic industry to focus on innovation in

design, materials, assembly and SMT recipes.

FCBGA - Lid Package Warpage Characteristics

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• For FCBGA with Lid, the dynamic warpage depends on the lid design and attachment, substrate, body thickness, die size and etc.

PBGA Package Warpage Characteristics

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• In PBGA package construction, mold properties play a significant role in controlling the package warpage due to the dominant ratio of the mold volume.

• The different range of warpage depends on the material and geometry used.• Among these PBGA’s, all meet the Jedec guideline in reflow temperature warpage. Depending on the solder

system or mold material used, the high temperature warpage can refer to 183C-220C for PbSn or 220C-260C for Pb-free

Different mold

PBGA Package Warpage Characteristics

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• For larger PBGA packages, the magnitude of warpage can be significantly higher.• If the solder system is Pb free, some of the package warpage magnitude shown exceeds the Jedec

guideline.• If the solder system is PbSn, all of the PBGA meet the Jedec guideline.

Different mold

Thermal Shadow Moiré Confocal

Dynamic Warpage Measurement Metrologies

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Projection Moiré 3D DIC Digital Image Correlations

Summary• Different packaging technology gives rise to different dynamic warpage

characteristic and challenges

• Understanding the dynamic warpage characteristic will enable the industry to continue innovate to overcome assembly challenges.– Better design integrations

– Better materials engineering (ultra low CTE)

– Better substrate build up process to account for residual stresses and packaging assembly process

– Robust surface mount process to enable high dynamic warpage package assembly yield.

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iNEMI: Warpage Characteristics of Organic Packages, Phase 3

iNEMI Technology Roadmap 2013• Identify package

warpage as key challenge

Phase 1 (2011-13)• Literature survey• Establish metrology

correlation between sites and increase awareness

• Reaching out to industry for component donation

• (Forming & Storming)

Phase 2 (2013-2014)• Establish current

technology package dynamic warpage (POP, PBGA, FCBGA)

• Measurement protocol (effect of “As Is”, “Bake” and Moisture Exposure Time (MET)) and sample size needed.

• (Norming)

Phase 3 (2015-2016)• Continue establishing

technology package dynamic warpage (all kind)

• Dynamic warpage measurement metrology assessment.

• (Performing)

Phase 4 (2016-2017)• Continue establishing

technology package dynamic warpage (all kind)

• TBD

Continuous focus on dynamic warpage characteristic of latest packaging technology and warpage measurement metrology

Thank you!

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Project Scopes in Phase 3 SOW

• to develop a better understanding of the current trends of warpage behavior for different package constructions. • Small BGA Packages:

• Interposer, 2.5D, 3D stack packages, through via silicon (TSV); Memory technology (High Band Width Memory, DDR)

• Large BGA Packages• Package stiffeners – picture frame stiffener, different stiffener attachment method, shapes and sizes• Either organic substrate or ceramic substrate

• System In Package/Multi Chip Package (BGA)• Stack Die or multiple die• Die on interposer and/or with asymmetrical layout.

• Embedded Package (embedded silicon, actives and passives)• *The measurement will be done at respective tool manufacturer.

Benchmark package warpage characteristics

• Identify measurement methods and protocols based on the different measurement techniques and technology such as below:• Confocal techniques• Projection moiré techniques• Thermo moiré techniques with or without convective reflow• 3D Digital Image Correlations (DIC)

Evaluation of current dynamic warpage measurement metrology

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Thermal Shadow Moiré Apparatus Convention and Preconditioning

Preconditioning Description

“As Is” Units used for board assembly immediately after taken out fromseal bag.

“Bake” Mimic condition where package moisture level being reset bybaking it for 24hrs at 125˚C

“MET 9 Days”Mimic 7 days component board assembly staging time + 2 days ofunforeseen delays. Exposed to 30 ˚C and 60%RH prior towarpage measurement

Thermo Moiré Metrology

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JEDEC Standard No. 22-B112A

Other warpage metrology can be found in JESD22-B112A