Using Tape & Reel for High Volume Flip Chip Delivery: A Manufacturing Analysis Presented at MCC/EIA/SEMATECH KGD Industry Workshop September 19, 1997 Joint Study by: Pat Jones - Delco Electronics Corporation Lisa Bernal Brethour - Surface Mount Taping, Inc. Tom Becker - 3M

Presentation Outline Background Test Plan Test Procedure Material Selection Wafer to Tape and Reel Results Transportation Test Results Bump Shape Analysis Spectral Analysis Pick and Place Test Results Conclusions and Recommendations

Statement of Need Need for low cost /high volume packaging Need to use existing SMT assembly equipment and tooling Need to use standardized embossed packaging media Need for documented research Need for industry standard for high volume flip chip packaging

Objective Determine feasibility of using standard embossed tape and reel packaging for flip chip ICs bumps down Determine functional “range of sizes” of flip chips in standard pockets Provide design model for sizing embossed pockets to flip chips Provide research to the semiconductor industry to assist in standardization

Experimental Scope Use a range of flip chip sizes Use a common flip chip thickness Develop experimental factorial design for chip size vs. pocket size Use common eutectic bumps with similar metallurgy Use of standardized FSTM shipping test method Use of standardized component handling equipment

Joint Division of Responsibilities

Process Flow Motorola Bump Wafer to Tape Test/Assembly 3M Tape & Reel Delco Electronics Wafers Motorola Bump Wafer to Tape Test/Assembly 3M Tape & Reel Motorola, SPS

Flip Chip Description *Bump Metallurgy: Eutectic Sn/Pb 60/40 or 63/37

Flip Chip Photos 8 mm Tape Photos to scale 24 mm Tape 12 & 16 mm Tape MSFB,4-UP MSFB FDIZ 8 mm Tape Photos to scale MFDS 24 mm Tape 12 & 16 mm Tape

Embossed Carrier Description 3M™ Conductive Polycarbonate Carrier 3000BD 3M™ Conductive PSA Cover Tape 2666 Precision Flat-bottom Pockets All pockets (except TC10) are “worst-case” for bump contact with carrier Bevel Edge with Raised Cross-bar pocket design Bevel < 35 deg. . Bare Die Bevel at 50% of Ko Flat-bottom Pocket < 3.0 deg. Draft Angle Inside Corner

Bevel Edge Pocket Design Low Draft Angles for better containment! (< 5.0 degrees) Bevel-edge pocket design for ease of use in loading! Precision Flat-Bottom Pocket (+/- 0.002”) Actual Cross-Section of 3M CSP Carrier Tape

Pocket Sizing Factorial

Wafer-to-Tape Process 100% visual inspection performed prior to pick manually inked damaged chips Bumps inspected to Delco Electronics Workmanship Standards Manually placed control dice in Gel-Pak®, bumps up Generated vibration samples versus control in tape and reel Gel-Pak® is a product of Vichem Corporation

Wafer-to-Tape Equipment

Wafer-to-Tape Saw street variation from wafer-to-wafer affected system alignment Initial tape designs were difficult to seal, re-designed tape to resolve problem Vacuum tip needed re-design to pick up bumped die reliably

Wafer-to-Tape Results

Packaging and Shipping Method Partially filled 13” reels Anti-static bags Placed in primary shipping container (pizza box) with anti-static bubble wrap Placed in secondary shipping container with anti-static bubble wrap Shipped UPS Red - Tempe, AZ to Kokomo, IN

Delco Electronics Test Flow Inspect 40 Die for Bump Damage Measure 10 Die for Flatness Photograph typical and atypical damage Spectral Analysis 5 die Tape Sample 1A 50 die - Control Inspect carrier pockets Tape Sample 1B 450 Die - Test Shipping Test Pick & Place 400 die Collect rotation data Collect mis-pick data Gel-Pak® control samples Reflow % of Die Cold Joint Analysis Reflow % of Die Cold Joint Analysis

Shipping Test Federal Standard Test Method 101C: Vibration Method 5019.1 Vibrate on 3 sides - one hour each 0.5” unrestrained vertical movement Drop Test Method 5007.1 Level B, procedures b, c and f 27” drop height

FDIZ Bump Photos Control Gel-Pak® Control Tape & Reel Test Sample SEM Photos

MSFB Bump Photos Control Gel-Pak® Control Tape & Reel Test Sample SEM Photos

MSFB4UP Bump Photos Control Gel-Pak® Control Tape & Reel Test Sample SEM Photos

FB250 Bump Photos Control Gel-Pak® Control Tape & Reel Test Sample SEM Photos

Bump Height Statistical Analysis Using computerized optical measuring system Repeatable to 2.5 um Analysis of mid-size FB250 bumps Analyzed bump heights and flatness Average and sigma

Bump Heights - Average

Bump Heights - Sigma

Bump Spectral Analysis Uncontaminated Contaminated Out of 50 flip chips analyzed with 48 bumps each (2, 400 bumps), only this small particulate of contamination was detected during spectral analysis.

Substrate Assembly Process SMD equipment with standard feeders (blind pick!) Data collection Rotation of flip chips in pockets Mis-pick information Reflow on test PCBs Comparison of modules with control vs. tested flip chips

Pick and Place Test Results *P&P #1 vacuum chuck was not optimized for small die and had difficulty picking up the FDIZ components. *P&P #2 vision system was not optimized for large components and had difficulty “seeing” the large components.

Conclusions and Recommendations Use of standardized embossed tape & reel solves high volume/low cost transportation needs Must limit die movement to < 10 degrees to prevent die damage Carrier should be cleaned prior to use Existing SMT placement equipment is capable of blind picking flip chips from carrier tapes

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