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SEMI G16-88 © SEMI 198 3, 1996 2 5 Dimensions 5.1 Dra w ing must show dimension s fo r the following items, if applicable: 1. P ackag e length 2. P ackage w idth 3. Top cavity thickness 4. Bottom cavity thick ness 5. Fra…

SEMI G16-88 © SEMI 1983, 19961

SEMI G16-88

SPECIFICATION FOR DIMENSIONS AND TOLERANCES USED TO

MANUFACTURE PLASTIC CHIP CARRIER TOOLING

1 Preface

This document is a guideline for the ordering of tooling

required to mold and form plastic chip carriers. It is to

be used by packaging engineers, mold manufacturers

and end of line tool makers as the basis for defining the

limits of manufacturing tolerances.

2 Applicable Documents

Related information may be found in:

MIL-STD-100

— Engineering Drawing Practices

ANSI Y14.5

— Dimensioning and Tolerancing

JEDEC Publication No. 95

— Outline for

Semiconductor Devices

3 Selected Definitions — Pr oduction Criteria

Tolerance Limits

3.1 mismatch and offset — Defined with respect to

package only. All statements will be equally applicable

in two (2) axes. All mismatch and offset measurements

are made after molding and prior to trimming.

3.1.1 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.)

3.1.2 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

top cavity position relative to the bottom cavity

position. (See Figure 2.)

3.2 Molded Protrusions

3.2.1 parting line protrusions — Those plastic

excesses which remain as a normal characteristic after

normal molding, deflashing, trimming, and singulation.

(See Figure 6.)

3.2.2 top or bottom protrusions — Those plastic

excesses (includes ejector pin “crowns”), which remain

1 Military Standards, Naval Publications and Form Center, 5801

Tabor Avenue, Philadelphia, PA 19120

2 ANSI, 1430 Broadway, New York, NY 10018

3 JEDEC, 2001 Eye Street, N.W., Washington, D.C. 20006

as a normal characteristic extending from the smooth

surface of the molded package.

3.3 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 6.)

3.4 lead shoulder protrusions and intrusions — Any

variations in straightness along the defined shoulder

width caused by dambar removal. (See Figure 6.)

3.5 package warpage — Any non-linear dimensional

change from the mold cavity characteristic, usually

caused by incorrect package design or molding

practices. (See Figure 3.)

3.6 shoulder bend location — Measured from the

outermost point of the shoulder bend radius. (See

Figure 4.)

3.7 lead co-planarity — Defined as the vertical lead

position with respect to a reference plane measured

after forming. (See Figure 5.)

4 Ordering Information

4.1 Purchase orders for tooling for plastic molded

quad 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 should be included.

2. A list of any tolerance limits which will differ

from those detailed in Section 6.

3. The type of tooling steel required.

4. The type of leadframe material 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.

8. The type of molding press to be used,

including power requirements.

9. Applicable leadframe drawing, including all

dimensions.

SEMI G16-88 © SEMI 1983, 1996 2

5 Dimensions

5.1 Drawing must show dimensions 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 center line

7. Ejector bottom locations from cavity center

line

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 Dimensional Tolerance

Limits for PCCs

6.1 In recognizing that every manufacturing process is

subject to variation, the following list details the

acceptable limit of this variation:

CAVITY MISMATCH

0.004" (0.101 mm)

PACKAGE/FRAME

OFFSET

0.002" (0.05 mm) (excluding

leadframe tolerances)

MOLDED PROTRUSIONS

(see Figure 6)

Parting line 0.006" (0.15 mm)

Top or bottom 0.001" (0.025 mm)

VARIATION IN LEAD POSITION

(see Figure 6) 0.004" (0.101 mm)

SHOULDER INTRUSIONS AND PROTRUSIONS

(see Figure 6) Intrusions 0.002" (0.05 mm)

Protrusions 0.003" (0.08 mm)

PACKAGE WARPAGE

Warp factor 2.5

LEAD CO-PLANARITY

0.003" (maximum)

EJECTOR PIN DEPTH

0.010" (maximum)

7 Sampling

7.1 Samples used to determine compliance to Section

6 shall be determined between vendor and supplier.

8 Packaging

8.1 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

Figure 2

Figure 3

Figure 4

Shoulder Bend Location

VERTICAL, LEAD POSITION

Figure 5

Coplanarity

Figure 6

Parting Line Protrusion and Variation in Lead

Locations — Vertical Lead Position

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.

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