Soumalya-HOY tester-University of Alberta (ECE 512)

ECE 512 Fall 2012 Presentation

Can IC testing Go Wireless? Introduction to the HOY tester

Soumalya Ghosh(1304792)

University of AlbertaElectrical and Computer Engineering

[email protected]

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Outline

• Motivation• IC testing strategies vs. VLSI technology• Wireless testing – the new standard– Introduction to wireless testing

• Types of wireless testing techniques– RF Communication technique– NF Communication technique– Optical Communication technique

contd. …

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Outline (2)

• The new platform – HOY– Introduction to the HOY tester

• The HOY approach• HOY operation• Advantages of HOY• Test flow (HOY)• Future work

Motivation

• Probe card costs• Probe card alignment issues• Contact causes wear and tear in the chip• Maintenance and cleaning issues of cards• Testing is the only category of cost which

doesn’t decrease with advanced fabrication1

• Increased pin count, speed, timing accuracy requirements

1. Semiconductor Industry Association, ITRS Report, 2003 Edition, 2003

IC testing strategies vs. VLSI technology

Fig. 1: Microprocessor clock rates2

2. Bushnell, Michael, and Vishwani Agrawal. Essentials of electronic testing for digital, memory, and mixed-signal VLSI circuits. Vol. 17. Springer, 2000.

The scenario

Table 1: VLSI Chips – present and future3

3. D. Herrell, "Power to the Package," IEEE Spectrum, vol. 36, no. 7, pp. 46-53, July 1999

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Wireless testing – the new standard

• Replaces conventional i/o pins in probe cards with wireless links

• Specially suitable when pin density is very high in the DUT

• Higher reliability due to reduced mechanical stress

• No creation of debris• Faster data rates possible than with cards

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RF Communication technique

• Also called as ‘Far Field’ communication technique

• Transceivers are placed on the wafer• Size overhead may result• Provides long range• Power supply considerations

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NF Communication technique

• Energy transmitted through varying EM field (quasi-static EM field)

• Consumes low power• Eliminates reflection issues• More efficient than RF technology for shorter

distances

Fig. 2: Near and far fields around RF source

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Optical Communication Technique

• High frequency EM fields• Almost immune to interference• Exploited using LDT (Laser Direct Testing)– Laser – metal interaction– Photoelectron emission, etc

The new platform – HOY

Developers are:Cheng Wen Wu, Shi-Yu Huang, Po-Chiun Huang, Tsin-Yuan Chang and Yu-Tsao Hsing,Dept. of Computer Science, National Tsing Hua University, Taiwan

and

Chih-Tsun HuangDept. of Electrical Engineering, National Tsing Hua University, Taiwan

contd. …Wu, Cheng-Wen, et al. "The HOY tester-Can IC testing go wireless?." VLSI Design, Automation and Test, 2006 International Symposium on. IEEE, 2006.

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Introduction to the HOY tester

• A novel wireless test system with enhanced embedded test features

• Conceived in 2003, launched in 2005, called HOY – (Hypothesis, Odyssey and Yield)

• Provides test solutions for wafer test, final test after packaging and field tests and diagnostics

• Reduced capital investment, simplified test flow and increased parallelism reduces cost

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The HOY approach

HOY

HypothesisOdyssey

Yield

Fig. 3: The HOY approach

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Hypothesis

It is getting harder for the ATE :i. to keep up with the pin count, speed and timing

accuracyii. to maintain reasonable cost level and satisfy

above requirementsiii. to maintain quality and yield for wafers bare dies

and packaged chips According to the HYPOTHESIS, we can solve

all these issues with wireless test

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Odyssey

• HOY is a long term project with some key technologies still immature

• We expect the technological expertise required for the implementation of HOY be available sometime in the recent future

• Within 10 years time significant portion of IC testing to go wireless

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Odyssey (2)

Fig. 4: HOY applications:

a) Wafer test

b) Chip test

c) Field diagnosis

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Yield

1. It performs wafer-level test and burn-in 2. It supports at-speed testing (by BIST)3. It greatly improves the defect level before the

dies are packagedHowever,4. Complete BIST (and BISR) solutions5. Stable and low cost wireless communication6. Contactless power supply, security, pin/pad test

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HOY operation

Fig. 5: The HOY test system with contactless power supply

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Advantages of HOY

• It performs wafer level test and burn-in• It supports at-speed testing (by BIST)• It greatly improves the defect level before the

dies are packaged• In conventional test flow there are redundant

tests• Wafer level burn-in and test can be done in a

more cost-effective way• Bottleneck in pin count is removed

Greatly simplified test runs:• Burn-in is done at the wafer level• Both burn-in and wafer level tests are by BIST• Further tests depend on packaging needs– If packaged, final tests are done after packaging– If not, KGD (known-good-die) should be guaranteed

up to the allowable defect level• Final test contains pin test, basic functional

test, AC test and speed sort

Test flow (HOY)

Wu, Cheng-Wen, et al. "The HOY tester-Can IC testing go wireless?." VLSI Design, Automation and Test, 2006 International Symposium on. IEEE, 2006.

• For non-packaged dies all tests are completed at the wafer level

• BISR repairs after the BIST detects any fault• CUTs have their own BISR module in-built

Test flow (HOY) (2)

Wu, Cheng-Wen, et al. "The HOY tester-Can IC testing go wireless?." VLSI Design, Automation and Test, 2006 International Symposium on. IEEE, 2006.

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Future work

Proposed technologies for HOY:

A. Enhanced Embedded Test FeaturesB. Wireless Transmission and Contactless PowerC. Test Interface and TestersD. Protocols, ID and Security

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References

1. Semiconductor Industry Association, ITRS Report, 2003 Edition, 2003

2. Bushnell, Michael, and Vishwani Agrawal. Essentials of electronic testing for digital, memory, and mixed-signal VLSI circuits. Vol. 17. Springer, 2000.

3. D. Herrell, "Power to the Package," IEEE Spectrum, vol. 36, no. 7, pp. 46-53, July 1999

4. Wu, Cheng-Wen, et al. "The HOY tester-Can IC testing go wireless?." VLSI Design, Automation and Test, 2006 International Symposium on. IEEE, 2006.

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Questions