Project Call for Participation: Conformal Coating Evaluation for Improved Environmental Protection, Phase 2 Listen to the webinar recording: https://youtu.be/JadBuYKKqjM If you have trouble accessing this video, please contact Haley Fu ([email protected])

April 6/7 & 13, 2021

Project Chair: Prabjit Singh (IBM) Co-Chair: Chen Xu (Nokia) iNEMI Project Manager: Haley Fu Agenda

• Introduction of Project Chairs • iNEMI Project Development Process • Companies Involved in Planning • Project Briefing • Objectives • Previous Related Work • Scope • Timeline • How to Join • Q&A

Note: All phones will be on mute until the end of the presentation

2 Introduction of Project Chairs

Dr. Prabjit Singh (IBM) Dr. Chen Xu (Nokia Bell Labs) Job title: Senior Technical Staff Member Job title: Distinguished member of technical staff Experience: 1. 42 years of metallurgical engineering Experience: and failure analysis of computer power 1. BS Degree in Chemistry from Tongji University in packing and cooling , China; Ph.D. in Physical Chemistry from Ruhr-University Bochum, Germany 2. 2 years of superconductor 2. ~100 publications, 40 presentations, 3 book chapters, manufacturing and characterization. 15 approved and pending patents. 3. 7 years of thin film technology and 3. Member of ACS, AVS, AESF and has participated in electro-migration characterization. various AESF, iNEMI, HDPUG and IPC committee 4. 83 patents issued. activities resolving industry-wide issues and developing standards

3 iNEMI Project Development Process

1 CONCEPT

2 DEFINITION “ Initiative” Open for Industry input 3 PLANNING ------iNEMI Technical Committee (TC) Approve SoW & PS 4 LAUNCH

5 EXECUTION “ Project” Limited to committed Members 6 CLOSURE iNEMI Project Management Policy

• Two governing documents for projects • SOW (statement of work): sets out project scope, background, purpose, benefits, and outlines required resources, materials, processes, project schedule, etc. • Project Statement (PS): signed by participating companies to secure commitment on resource and time contributions.

• iNEMI Project requires iNEMI membership • Signed membership agreement • Commitment to follow iNEMI By-laws and IP policy

5 Project Briefing Project Background and Objective

§ Conventional test determines the times to failure of coated components, which has disadvantages: – Done in dry sulfur environment at 105 oC. – No moisture and no gas besides sulfur. – Takes many months.

§ Test should be able to determine conformal coating performance – in less than a week – under environmental conditions like the application conditions.

7 Conventional method

Results of corrosion of 0603 resistors in FoS chamber at 105 oC

RUB Control

EP1

Courtesy: M. Gaynes and 2017-2018 project team

©2018 Universal Instruments PAGE: 8 Phase 1: Project team

Prabjit Singh, Larry Palmer Mei Ming Khaw, Kok-Lieh Tan IBM Corporation, Poughkeepsie, Keysight, Penang, NY, USA Mike Huang, Ruby Chen Xu Wistron Corporation, Hsinchu, Nokia, Murray Hill, NJ, USA

Jason Keeping Haley Fu Celestica, Toronto, Canada iNEMI, Shanghai, China

Marko Pudas Picosun, Masala, Finland Phase 1: Thin film method

§ Cu and Ag thin films are conformally coated and exposed to a corrosive environment. § The corrosion rates of the coated metallic thin films are electrically measured and used to quantitatively characterize the conformal coatings. § The corrosion rates of coated and uncoated metallic films are compared.

10 Phase 1: Test setup with FoS

The relative humidity in the chamber was kept constant using a saturated salt solution.

The sulfur gas concentration was kept constant at 0.15 ppm by keeping the chamber temp at 40 oC; and at 0.30 ppm at 50 oC.

The chamber air was not stirred. Phase 1: Bare silver and copper films corrosion rates

th( t = 0)

Rate of loss of metal thickness

12 Phase 1: Acrylic coating performance

Rate of loss of metal thickness

13 Phase 1: 50 °C, 15 %RH chamber, film corrosion after 5.32 days

Silver thin films Copper thin films

Silicone protects ALD protects Ag Silicone protects ALD and acrylic Ag well at 40% well. Cu poorly. protects Cu well. RH but not at Acrylic protects 50% RH. Ag poorly. Phase 1: Conclusions

§ This study shows that conformal coatings can be characterized by the degree of corrosion protection provide by the coatings as measured by the rates of corrosion of the underlying copper and silver thin films. – The test duration is less than a week compared to a year long test if done by conventional means. – It can differentiate the performance of different coatings.

15 Phase 2: Objective & Scope

§ Compare the performance of conformal coatings subjected to the flower of sulfur (FoS) chamber environment to the performance seen when using a mixed flowing gas (MFG) chamber environment under targeted corrosion rate, temperature and humidity range.

§ The MFG environment is expensive but well established in the industry for testing electronic hardware for susceptibility to atmospheric corrosion.

§ Refine the test design (air circulation for FoS) and provide test recommendations and guidelines to the industry for both the FoS and MFG testing approaches.

§ Explore the test vehicle design on PCBA and the test feasibility

16 Phase 2: Proposed experiment plan

§ FoS temperature and humidity § Coatings: conditions with circulated air: – Acrylic – Temperature: 40 oC – Fluoropolymer – Relative humidity: 15%, 31% – ALD and 75% § Current through thin films – 100, 200, 300 and 100 mA. § MFG test condition – Gases concentration: Electrical and temperature test − SO2: 200 ppb conditions for the FoS chamber at 40 °C − H2S: 1000 ppb Duration, Current, Nominal film temp − NOx: 1000 ppb days mA and %RH, °C − Cl2: 50 ppb 0-1.85 100 42 °C, 13.5% – Temperature: 30 oC 1.85-3 200 52 °C, 8.2% 3-4.16 300 64 °C, 4.6% – Relative humidity: 15%, 31% 4.16-5.32 100 42 °C, 13.5% and 75%

17 Phase 2: Schedule

Timeline starts from the project sign-up when the participating team members are confirmed.

Tasks Months 1 2 3 4 5 6 7 8 1. Solidify the experiment plan details x 2. Prepare the testing resource, serpentine thin film coupons x 3. Coat the coupons, arrange shipment x 4. FOS test runs to characterize conformal coatings x x x 5. MFG test of coated and uncoated thin films x x x x x 6. Summary & Final report x x 7. Explore possible test on the PCBA x x x x x x

18 How to Join Sign-Up Due on April 30, 2021

• iNEMI membership is required to join the project • Download SOW and PS from iNEMI web: • https://community.inemi.org/conformal-coating2 • Sign the PS • Signature of representative of participants • Signature of manager approval • Send scanned PS to [email protected] • iNEMI Vice President of Technical & Project Operations will sign and approve your participation and send you back the completed PS with acceptance • Join iNEMI membership, or questions, contact Haley Fu ([email protected])

20 Q&A www.inemi.org

Haley Fu [email protected]