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SEMI G37-88 © SEMI 198 6, 1988 2 8. The type of molding pr ess to be used, includin g power requirem e nts. 9. Applicable leadf r ame drawing, including all dimens ions. 5 Dimensions 5.1 D rawin g must show dimens ion fo…

SEMI G37-88 © SEMI 1986, 19881

SEMI G37-88

SPECIFICATION FOR DIMENSIONS AND TOLERANCES USED TO

MANUFACTURE PLASTIC MOLDED SMALL OUTLINE PACKAGE

TOOLING

1 Preface

This document is a guideline for the ordering of tooling

required to mold and form plastic molded small outline

semiconductor packages. It is to be used by packaging

engineers, mold manufacturers, and end-of-line

toolmakers as the basis for defining the limits of

manufacturing tolerances.

2 Applicable Documents

2.1 ANSI Specification

Y14.5 — Dimensioning and Tolerancing

2.2 JEDEC Specification

Pub. No. 95 — Registered and Standard Outline for

Semiconductor Devices

2.3 Military Specification

MIL-STD-100 — Engineering Drawing Practices

3 Selected Definitions — Pr oduct Criteria

Tolerance Limits

mismatch and offset — defined with respect to package

only. As this family of packages has four sides, all

statements will be equally applicable in two (2) axes.

All mismatch and offset measurements are made after

molding and prior to trimming.

cavity to frame offset — will be measured prior to any

trimming operation. Offset will be defined as the

difference in bottom cavity position with respect to a

leadframe datum. The offset measurement will exclude

leadframe tolerances (see Figure 1).

top to bottom cavity mismatch — characterized by the

fact that the top and bottom cavities in the mold are not

aligned properly, causing a mismatch condition. The

measurement shall be stated as the difference in the

package top cavity position relative to the bottom cavity

position (see Figure 2).

parting line protrusions — those plastic excesses which

remain as a normal characteristic after normal molding,

deflashing, trimming, and singulation (see Figure 3).

1 ANSI, 1430 Broadway, New York, NY 10018

2 JEDEC, 20001 Eye Street, N.W., Washington, D.C. 20006

3 Military Standards, Naval Publications and Form Center, 5801

Tabor Avenue, PA 19120

top or bottom protrusions — those plastic excesses

(includes ejector pin crowns), which remain as a normal

characteristic extending from the smooth surface of the

molded package.

variations in lead location — defined with respect to a

90° angle from the top or bottom of the smooth surface

of the molded package as viewed on the end or side

projections (see Figure 3).

lead shoulder intrusions and protrusions — any

variations in straightness along the defined shoulder

essentially caused by dambar removal (see Figure 3).

package warpage — any non-linear dimensional

change from the mold cavity characteristic, usually

caused by incorrect package design or molding

practices (see Figure 4).

shoulder bend location — measured from the outermost

point of the shoulder bend radius (see Figure 5).

lead co-planarity — defined as the vertical lead

position with respect to a reference plane measured

after forming. The reference plane is defined by the

three lowest leads from the bottom of the package (see

Figure 6).

4 Ordering Information

4.1 Purchase orders for tooling for plastic molded high

density TAB semiconductor packages furnished to this

specification shall include the following items:

1. A package tooling outline drawing showing all

required dimensions listed in Section 5. Package

surface finish to be included.

2. A list of any tolerance limits which differ from

those in Section 6.

3. The type of tooling steel required.

4. The type of leadframe material and temper to be

used.

5. The type of plastic to be molded (if proprietary, a

statement of its shrinkage characteristics).

6. Sampling plan for compliance to Section 7.

7. The number of spare parts or expendable parts

desired.

SEMI G37-88 © SEMI 1986, 1988 2

8. The type of molding press to be used, including

power requirements.

9. Applicable leadframe drawing, including all

dimensions.

5 Dimensions

5.1 Drawing must show dimension for the following

items, if applicable:

1. Package length

2. Package width

3. Top cavity thickness

4. Bottom cavity thickness

5. Frame thickness

6. Ejector top locations from cavity centerline

7. Ejector bottom locations from cavity centerline

8. Ejector size (top and bottom)

9. Ejector depth (top and bottom, draft angle top side,

bottom side, and end)

10. End notch shape, depth, width, length

11. Pin 1 ID location from package center

12. Pin 1 ID shape and size

13. Corner radius or sides

14. Corner radius or ends

15. Lead spread (nominal)

16. Shoulder bend location

17. Shoulder width

6 Product Criteria — Dimen sional Tolerance

Limits for S.O. Packages

6.1 In recognizing that every manufacturing process is

subject to variation, the following list details the

acceptable limit of this variation:

CAVITY MISMATCH

(See Figure 2) 0.05 mm (0.002")

PACKAGE/FRAME OFFSET

(See Figure 1), (excluding leadframe

tolerances)

0.05 mm (0.002")

MOLDED PROTRUSIONS

(See Figure 3) Parting line 0.15 mm (0.006")

Top or bottom 0.025 mm (0.001")

VARIATION IN LEAD LOCATION

(See Figure 3) 0.101 mm (0.004")

SHOULDER INTRUSIONS AND

PROTRUSIONS

Intrusions 0.025 mm (0.001")

Protrusions* 0.004"

PACKAGE WARPAGE

Warp factor: 2.5

LEAD CO-PLANARITY

0.003" (maximum)

EJECTOR PIN DEPTH

0.003"

* Assumes 0.002" design protrusion.

7 Sampling

Samples used to determine compliance to Section 6

shall be determined between user and supplier.

8 Packaging

Tooling must be packed in containers designed and

constructed to prevent damage and/or contamination.

Specific protection must be provided if tooling is to be

shipped any great distance.

Figure 1

Cavity to Frame Offset

Figure 2

Cavity Mismatch

Figure 3

Parting Line Protrusions