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SEMI G65-96 © SEMI 1996, 2004 2 5 Summary of Method 5.1 The leadframe samples (etched using a standard mask agreed between user and supplier) will be formed using a “W” forming tool. The resul ting form angle is to be me…

1 SEMI G65-96 © SEMI 1996, 2004

SEMI G65-96 (Reapproved 1104)

TEST METHOD FOR EVALUATION OF LEADFRAME MATERIALS

USED FOR L-LEADED (GULL WING TYPE) PACKAGES

This test method was technically approved by the Global Assembly & Packaging Committee and is the direct

responsibility of the Japanese Packaging Committee. Current edition approved by the Japanese Regional

Standards Committee on July 23, 2004. Initially available at www.semi.org September 2004; to be published

November 2004. Originally published in 1996.

1 Purpose

1.1 This test method describes an evaluation method

for bending characteristics of leadframe materials used

for L-leaded packages.

NOTE 1: The lead fatigue test described in MIL-STD-

883/2004 is not suitable for evaluating the bending

characteristics of fine pitch leadframes or leadframes used for

L-leaded packages because the method is based on reforming

the leads.

2 Scope

2.1 This test method may be applied to leadframes for

L-leaded packages such as QFP, SOP, TSOP, etc.

2.2 This test method may also be applied to any

leadframe materials with thickness  0.15 mm.

2.3 The test method may be used in trim and form tool

suppliers, leadframe material suppliers, leadframe

manufacturers, and package engineers.

NOTICE: This standard does not purport to address

safety issues, if any, associated with its use. It is the

responsibility of the users of this standard to establish

appropriate safety and health practices and determine

the applicability of regulatory or other limitations prior

to use.

3 Referenced Standards

3.1 Military Standard

MIL-STD-983 — Method 2004, Lead Integrity

NOTICE: Unless otherwise indicated, all documents

cited shall be the latest published versions.

4 Terminology

4.1 Definitions

4.1.1 crack (of leadframe) — Micro cleavage or

fracture on surface of outside of lead which is caused

by bending (see Figure 1).

1 United States Military Standards, Available through the Naval

Publications and Forms Center, 5801 Tabor Avenue, Philadelphia,

PA 19120-5099, USA. Telephone: 215.697.3321

Figure 1

Crack

4.1.2 orange peel (of leadframe) — Micro roughness

on surface of outside of lead caused by bending (see

Figure 2).

Figure 2

Orange Peel

4.1.3 spring back — Difference between designed

angle of forming tool and actual lead form angle.

NOTE 2: In this method, the angle of forming tool is 90°.

The value is defined by: Actual lead bend angle 90°.

5 Summary of Method

5.1 The leadframe samples (etched using a standard mask agreed between user and supplier) will be formed using a

“W” forming tool. The resulting form angle is to be measured and surface characteristics such as cracking and

orange peel are to be visible for compliance to the agreed upon specification.

6 Interference

6.1 If the forming tool does not meet the specification, lead movement during forming may result in poor

repeatability.

7 Significance

7.1 Devices manufactured with leadframes of different spring back characteristics may cause board assembly

problems, due to lead positional differences.

7.2 Crack in the leadframe may cause poor contact reliability with board.

8 Equipment

8.1 Tensile Tester — With minimum 9800N force and 1% accuracy.

8.2 “W” Forming Tool — With R = 0, 0.1 and 0.2 and form angle of 90°. The dimension and configuration are

shown in Figures 3–7.

Figure 3

W-Bending Test Tool

Figure 4

Upper Tool Detail

Figure 5

Lower Tool Detail