Designguidelinesforaluminumwirewedgebonding.doc

REVISION HISTORY
Revision
Description of Change
Writer/Reviser
Effective Date
A
New Release
Weifeng Liu/Dick Pang
10/03/2013

Optional Section (see footnote)
APPROVERS
Author Name
Title
Department Name
Weifeng Liu
Senior Microelectronics Engineer
MEP, AEG
Dick Pang
Microelectronics Engineer
MEP, AEG

Author’s Manager Name
Title
Department Name
Anwar Mohammed
Senior Director
ATT/MEP, AEG

AEG VP Name
Title
Department Name
Murad Kurwa
Advanced Engineering Group VP
Advanced Engineering Group

Optional Section
ABOUT FLEXTRONICS

Flextronics is a leading Electronics Manufacturing Services (EMS) provider focused on delivering complete design, engineering and manufacturing services to automotive, computing, consumer, industrial, infrastructure, medical, clean tech and mobile OEMs. Flextronics helps customers design, build, ship, and service electronics products through a network of facilities in 30 countries on four continents. This global presence provides design and engineering solutions that are combined with core electronics manufacturing and logistics services, and vertically integrated with components technologies, to optimize customer operations by lowering costs and reducing time to market.

1.0 BACKGROUND/INTRODUCTION
1.1. N/A

2.0 PURPOSE
2.1. This document was created to present aluminum wire wedge bonding process capability and design guidelines we can offer to current and potential new customers.

3.0 SCOPE
3.1. This document is mainly to cover the following processes:
· Aluminum ultrasonic wedge bonding

4.0 DEFINITIONS and ABBREVIATIONS
4.1. N/A

5.0 REFERENCES

Document Title
Document Number
Document \ Hyperlink
Guidelines for Chip-on-Board Technology Implementation
IPC-SM-784

TEST METHOD STANDARD MICROCIRCUITS
MIL-STD-883H

6.0 POLICY STATEMENT
6.1. N/A

7.0 PROCESS FLOW CHART

Aluminum Wedge Bonding Process

8.0 PROCEDURE

9.0 RESPONSIBILITY
9.1. N/A

10.0 TRAINING REQUIREMENTS
10.1. N/A

11.0 KEY PERFORMANCE INDICATORS AND METRICS
11.1.

Al Wire Ultrasonic Wedge Bonding Spec
Standard

General design rules
Aluminum wire metallurgy
Al 98.9%, Si 1%

Aluminum wire diameter
0.8 mil for 60 um pitch

Chip bond pad geometry
Rectangle prefer

Chip bond pad dimensions
Min 52x65 um with 60um pitch

Chip bond pad pitch
Min. 60um

Substrate pad metallurgy
Electrolytic Nickel: 2.5um min (100 micro inch), Electrolytic Gold: 0.4~0.9um (16-35 micro inch)

Substrate pad dimensions
Rectangle prefer

Bond-bond loop length
Min. 0.3mm for die to die bonding, 0.6mm for down bond wire length. Max. (<100 times of wire diameter)

Bond-bond loop height
Max 7 mil

Qualified Material List
Aluminum wire
0.8 mil wire from Cebu chip connections incorporated

Wedge bond tool
2130-1515-L-W=0.025 DSR (For Fine Pitch)
“30”= Wire Feed angle 30 deg series
“15”= Hole size 0.0015in; “15” = Bond length 0.0015
“L”= Wedge Length 0.828in
“W”= Wedge width 0.0025in
Vendor: Gaiser

Non conductive die attach
Henkel Ablebond 2025 D (Nagase ECM 357 -346 -5 to be evaluated)

Glob top encapsulation
Hysol EO1062

Dam material (for dam/fill process)
HYsol FP4451

Fill material (for dam/fill process)
Hysol FP4450

Process spec
Pad surface condition after cleaning
No contaminants

Process profile
Temperature: room temperature, 1st Bond Force: 14g, 1st Bond Power: 56Dac,1st Bond time: 14ms, 2nd Bond Force: 14g, 2nd Bond Power: 60Dac, 2nd Bond Time: 14ms

Wire pull testing
>=2.5g (for 0.8 mil wire)

Non-destructive wire pull
80% of preset minimum bond strength

Quality control
No devices shall be acceptable that exhibits:
· Ultrasonic wedge bonds on the die or package post that are less than 1.2 times or more than 3.0 times the wire diameter in width, or less than 1.5 times or more than 6.0 times the wire diameter in length.
· Thermosonic wedge bonds on the die or package post that are less than 1.5 times or more than 3.0 times the wire diameter in width or are less than 1.5 times or more than 6.0 times the wire diameter in length.
· Bond width less than 1.0 times the wire diameter for aluminum wires 2.0 mils or greater in diameter.
· Wedge bonds where the tool impression does not cover the entire width of the wire.
· Bonds on the die where less than 50% of the bond is within the unglassivated bonding pad area
· Wire bond tails exceed 2 times wire diameter in length on die and on post
· Bonds on foreign materials
· Bonds lifting or peeling

Reliability spec
Reliability testing
Follow component reliability qualification
· High temperature aging:125 C, 1000 hours (30)
· High temperature/high humidity: 85C/85%RH, 1000 hours (or with bias, 30)
· Temperature cycling: -55 C to 125 C, 1000 cycles (30)

IPC-SM-784

12.0 ASSESSMENT OF CONFORMANCE METHOD
12.1. N/A

13.0 RECORD RETENTION REQUIREMENT
13.1.

No
Record
Retention Period
Storage Location
Protection
Retrieval
Disposition
1.

(Note: This section is Mandatory if this Policy/Process/or Procedure is related to or leads to the generation of records.)
14.0 DOCUMENT REVIEW AND APPROVAL REQUIREMENTS
14.1. N/A

15.0 ATTACHMENTS/APPENDICES
15.1. N/A

Note:
This template provides a framework to document Policy, Process, and Procedures. The originator can add topics and sections as are required to bring clarity to the document. Additionally, the originator can delete sections that are not Mandatory or applicable.