Module & SiP Thermal Mgmt.Oct 19-20, 2017Shenzhen, China

Nader NikfarPrincipal Engineer/Mgr.Qualcomm Technologies, Inc.

2

Agenda

• Module & SiP components

• Thermal management challenges

• Thermal performance of SiP◦ Module level

◦ System level

◦ Comparison to conventional architecture

◦ In mobile platform

• Conclusions

3

Most SiPs are sub-systems for mobile devices

Module & SiPs

• SiP consists of

◦ Bare IC die

◦ Packaged IC die (2D/3D)

◦ SMT active and passive components

◦ Integrated passive devices (IPD)

◦ Embedded components

◦ Performance enhancements• Thermal lids

• Materials

◦ Thermal interface materials (TIM)

◦ Higher conductivity

• Shielding

• Stiffeners

Tracking devices

Smartphones

GPS SiPsRunning Monitors

WiFi/Bluetooth SiPsWearables

Tablets

3G/4G SiPsIoT/M2M

AutoUSB Dongles

POS

Examples of SiP

4

Thermal mgmt. of SiP is more challenging than SoC

Thermal Mgmt. Challenges

• SoC thermal challenge is still there◦ Heat source non-uniformity

◦ Floor planning

◦ Maintaining max. Tj across various IPs on a small die

• Additionally for SiP◦ High-density integration of components (2/2.5/3D)

◦ More components, smaller XY, thinner Z, high performance and functionality

◦ Higher heat flux density and mutual heating

◦ Cooling budgets mostly based on natural convection

◦ Multiple heat sources within one entity and multiple max. Tjs

• Consequently◦ Thermally-aware design approach “a must” for success

◦ System-level thermal mgmt./solution very critical to success of SiP

Example layout of a SiP

Exploded view of a SiP

5

Thermal Performance of SiP

SiP level knobs to improve performance

• Placement of ICs within SiP impacts the max. temp. of components• Proximity of hotter components

• Orientation

• Back to back placement (for double-sided designs)

• For higher-power chips, the conduction path to substrate must be

enhanced

• Enhance thermal conductivity of substrate by maximizing Cu content

along (X,Y,Z) as permitted by mechanical and electrical constraints

-4.0C

-1.3C

115.3C

Optimized placement impacts temp. distribution & magnitude

Enhance conductivity of substrate to maximize thermal performance

6

Thermal Performance of SiPSiP level knobs to improve performance

• Encapsulating SiP improves thermal performance

◦ Lower max. Tj values

◦ Extends time-to-throttle

◦ Lower thermal gradient

◦ Creates a single elevation at each side for

coupling to heat sink

◦ Larger effective heat transfer area

25

35

45

55

65

75

85

95

105

115

0 30 60 90 120 150 180 210 240 270 300

tem

pe

ratu

re [c]

time [sec]POWER AMPLIFIER (NO MOLD)

POWER AMPLIFIER (w/ MOLD)

POWER AMPLIFIER (w/ CU-MOLD)

Temperature rise over time for non-molded vs. 2 molded options

Lower max Tj values (left to right: non-molded, conventional mold, highly conductive moldImproved

Conduction

LCD Glass

LCD Module

Backcover

Battery

SiP in a typical smartphone (dual-side heat sinking)

IC 2

PC

B

Single elevation when molded

7

System Integration

Comparison to Conventional Architecture

IC 4IC 1

IC 2IC 3

PCB

IC 1PCB PCB

IC 4IC 3 IC 2 IC 1PCB PCB

IC 4IC 3 IC 2

180°

Substrate Substrate

Discrete SiP 1 SiP 2

Display module

Back cover

Screen

Mid-frame

Conventional chipset or SIP

Power distribution of chipset in Smartphone

810/19/2017 Qualcomm Confidential and Proprietary

Comparison to Conventional Architecture

IC 1 IC 2 IC 3 IC 4

Discrete 110.9 78.2 67.1 77.5

Module 1 92.2 65.7 61 73.9

Module 2 110.5 82.6 75.3 91.9

0

20

40

60

80

100

120

Te

mp

era

ture

(C

)

Steady state junction temperature

IC 4IC 1

IC 2IC 3

PCB

IC 1PCB PCB

IC 4IC 3 IC 2 IC 1PCB PCB

IC 4IC 3 IC 2

180°

Substrate Substrate

Conventional SiP 1

110.5

92.2

110.9

SiP 2

9

Thermal Performance of SiPTest data in mobile platform

Same phone with

SiP (25x25mm)

Conventional phone

with discrete chips

-10 C

IR scans of conventional vs. SiP solution at same boundary conditions

10

• Sip’s thermal performance as a standalone module (not heat sunk) isn’t good compared to conventional solutions

• Maximizing SiP’s thermal performance is a challenging task dependent on various variables:

◦ Components placement within SiP have to be analyzed to assure internal thermal performance of module is optimized

◦ Heat flux out of SiP should be maximized through both sides

◦ Coupling to system level thermal solution from both sides recommended (power dependent)

◦ The system thermal design and the placement of SiP within system impacts performance of SiP

• When above properly designed, SiPs thermal performance is better or equal to conventional solutions

• A thermally-aware design takes into account optimized chip and package-level heat transfer in addition to coupling

the SiP to a proper system level solution

• OEMs integrating SiPs into their platform:

◦ Co-design of system and coupling dynamics of SiP to system is a must for successful thermal performance

◦ Analyze heat transfer from SiP to ambient to assure thermal limits meet

• SiP's thermal performance is as good as system’s thermal solution

Conclusions

11

AcknowledgementSpecial thanks to following individuals at Qualcomm Technologies, Inc.

• Yang Zhang

• Ryan Lane

• Bohan Yan

• Damion Gastelum

Follow us on:

For more information, visit us at:

www.qualcomm.com & www.qualcomm.com/blog

Nothing in these materials is an offer to sell any of the components or devices referenced herein.

©2017 Qualcomm Technologies, Inc. and/or its affiliated companies. All Rights Reserved.

Qualcomm is a trademark of Qualcomm Incorporated, registered in the United States and other countries. Other products and brand names may be trademarks or registered trademarks of their respective owners.

References in this presentation to “Qualcomm” may mean Qualcomm Incorporated, Qualcomm Technologies, Inc., and/or other subsi diariesor business units within the Qualcomm corporate structure, as applicable.Qualcomm Incorporated includes Qualcomm’s licensin g business, QTL, and the vast majority of its patent portfolio. Qualcomm Technologies, Inc., a wholly -owned subsidiary of QualcommIncorporated, operates, along with its subsidiaries, substantially all of Qualcomm’s engineering, research and development fu nctions, and substantially allof its product and services businesses, including its semiconductor business, QCT.

Thank you