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SEMI G19-0997 © SE MI 1980, 1997 1 SEMI G19-0997 SPECIFIC A TI ON FOR DIP LEADFRAMES PRODUCED BY ETCHING 1 Preface This specification is a guideline for pro duction of DIP leadframes for plas tic molded semiconductor pac…

SEMI G18-96 © SEMI 1984, 19963

12.4 Any special packaging or shipping requirements

shall be agreed upon between supplier and purchaser at

the time of purchase.

13 Basis for Rejection

13.1 For the purposes of determining conformance

with the requirements prescribed in the specification,

any measured value outside the specified limiting

values shall be cause for rejection.

13.2 If objectionable material is found and rejected,

samples of the questionable material, with the defects

identified and marked, should be sent to the supplier

along with information as to order number, quantity

originally received, date received, and quantity rejected.

Rejected material should be held with adequate

protection and identification by the purchaser for a

reasonable amount of time, pending investigation by the

supplier.

NOTICE: These standards do not purport to address

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

responsibility of the user of these standards to establish

appropriate safety and health practices and determine

the applicability of regulatory limitations prior to use.

SEMI makes no warranties or representations as to the

suitability of the standards set forth herein for any

particular application. The determination of the

suitability of the standard is solely the responsibility of

the user. Users are cautioned to refer to manufacturer’s

instructions, product labels, product data sheets, and

other relevant literature respecting any materials

mentioned herein. These standards are subject to

change without notice.

The user’s attention is called to the possibility that

compliance with this standard may require use of

copyrighted material or of an invention covered by

patent rights. By publication of this standard, SEMI

takes no position respecting the validity of any patent

rights or copyrights asserted in connection with any

item mentioned in this standard. Users of this standard

are expressly advised that determination of any such

patent rights or copyrights, and the risk of infringement

of such rights, are entirely their own responsibility.

International), 3081 Zanker Road, San Jose, CA 95134. Reproduction o

the contents in whole or in part is forbidden without express written

consent of SEMI.

SEMI G19-0997 © SEMI 1980, 19971

SEMI G19-0997

SPECIFICATION FOR DIP LEADFRAMES PRODUCED BY ETCHING

1 Preface

This specification is a guideline for production of DIP

leadframes for plastic molded semiconductor packages

produced by the etching process. It is a design guideline

for packaging engineers, etchers, and mold

manufacturers and has been developed to meet the

requirements of automatic bonders.

2 Applicable Documents

2.1 SEMI Standards

SEMI G18 — Specification for Integrated Circuit

Leadframe Material Used in the Production of Etched

Leadframes

SEMI G10 — Standard Method for Mechanical

Measurement of Plastic Package Leadframes

2.2 Other Document

PCM1 D-300

— Standard Specification

3 Selected Definitions

burrs and protrusions — Fragments of excess material,

either horizontal or vertical, attached to the lead frame.

camber — Curvature of the leadframe strip edge (see

Figure 1).

Figure 1

Camber

coil set — Longitudinal bowing of the leadframe (see

Figure 2).

1 Photochemical Machining Institute, 4113 Barberry, Lafayette Hills,

PA 19444

Figure 2

Coil Set

compensation — Changes made in the dimensions on

the master artwork other than those specified on the

engineering artwork that allow for the process variables

(i.e., etch factor, undercut).

crossbow — Transverse bowing of the leadframe (see

Figure 3).

(enter graphic when available)

Figure 3

Crossbow

etch factor — The ratio of etched depth to the lateral

etch or undercut (see Figure 4).

Figure 4

Undercut and Etch Factor

functional area — The die attach pad and wire bond

(lead tip) area.

lateral etch or undercut — The allowable bevelled edge

caused by the leadframe etchant attacking the metal

laterally as well as vertically (see Figure 5).

Figure 5

Overetching

lead twist — Angular rotation of the bond fingers (see

Figure 6).

Figure 6

Lead Twist

offset alignment accuracy — The top to bottom

alignment accuracy of the etched leadframe operation

(see Figure 7).

Figure 7

Etched Offset

pits — Shallow surface depressions or craters in the

leadframe material (see Figure 8).

Figure 8

Pits

resist breakdown — Etching under the edges of the

resist causing more than a standard undercut.

undercut — Bevelled edge caused by the etchant

attacking the metal laterally as well as vertically (see

Figure 4).

4 Ordering Information

Purchase orders for leadframes for plastic molded

semiconductor packages furnished to this specification

shall include the following items:

1. Drawing number and revision level

2. Material

3. Number of leads

4. Material certification

5. Number of units/strip

6. Plating requirements

7. Packaging and marking (see Section 8)