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SEMI G18-96 © SEMI 198 4, 1996 3 12.4 Any special packaging or ship p in g requirements shall be agreed upon between suppl ier and purchaser at the time of purchase. 13 Basis for Re jection 13.1 For the purposes of deter…

SEMI G18-96 © SEMI 1984, 1996 2

7.4 Camber (Edgewise Curvature) — Camber is not

critical for material used in the etching process

provided the end product (leadframe strip) meets its

requirements; ± 0.0625" (1.6 mm) in 36" (91 cm) is

considered acceptable.

7.5 Coil Set — A three foot long sample shall be

obtained from each coil supplied. The measured coil set

shall not exceed 1.500" (38.1 mm).

7.6 Edge Burrs — Undesirable and, if present, their

height shall not exceed 10% of the metal thickness.

7.7 Crossbow (Dish) — Crossbow is a function of

slitting. Because material for the photo chemical

process is generally about 16–20" wide, crossbow is not

a critical problem. However, the final product

(leadframe strips) must meet maximums, as suggested

in Table 2, and crossbow in the sheet form, shall not be

present to the extent that this specification cannot be

met.

Table 2 Maximum Crossbow

Specified Strip Width Maximum Crossbow

Up to 1.000" (25.4 mm), incl. 0.003" (0.076 mm)

Over 1.000" (25.4 mm) 0.005" (0.127 mm)

7.8 Oil Can — When any part of a sheet is pushed, but

not bent, and it snaps into a different position or plane

other than the original position with no further pressure,

oil canning is present. Oil canning shall not be present

on materials being used in the photo chemical process

(etching) to the extent that the maximum crossbow

specification on the finished product (see Table 2)

cannot be met.

8 Surface Finish

8.1 The material shall be commercially free of surface

imperfections such as pits, nicks, dents, gouges,

scratches, laminations, or inclusions.

8.2 Surface defects less than 0.0003" (0.0076 mm) in

depth will be acceptable unless otherwise agreed upon

between the supplier and purchaser.

APPLICATION NOTE: There is a question regarding the

ability of material suppliers to meet this specification.

Revision of this specification is under review.

9 Corrosion

9.1 Visual inspection shall be used to determine if

objectionable surface oxides are present which would

render the product unusable for the intended

application. Objectionable conditions, if present, should

be reported to the supplier within 60 days after receipt

of the material.

9.2 There shall be no visible rust on the surface of

Alloy 42 material.

10 Coils

10.1 Unless otherwise specified, coils shall be

supplied with an inside diameter that provides for good

packing practice without resulting in excessive coil set.

11 Certifications or Test Rep orts

11.1 Requests for certifications or test reports shall be

made at the time of order entry or contract agreement.

They shall be furnished by the manufacturer within one

week of date of shipment.

11.2 When certifications are required, the following

information shall be supplied as a minimum:

1. Vendor name

2. Purchase order number

3. Vendor order number

4. Alloy name and number

5. Chemical analysis

6. Temper designation (reference only)

7. Tensile strength

8. Elongation percent in 2"

9. Electrical conductivity % IACS (for copper base

alloys only)

11.3 In the event of a disagreement between supplier

and purchaser, an independent test shall be conducted

on the strip to verify the data provided in the

certification.

12 Packaging and Marking

12.1 The material shall be separated by size,

composition, and temper, and prepared for shipment in

such a manner as to ensure acceptance by a common

carrier for transportation at the lowest applicable rate.

12.2 The material shall be suitably packaged to protect

from condensation, contamination, etc., and to afford

protection from the normal hazards of transportation.

12.3 Each shipping unit shall be legibly marked with

the purchase order number, alloy name or number,

temper, size, gross and net weight, and name of the

supplier. The specification number shall be shown

when specified on the purchase order.

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

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).