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SEMI G75-0698 © SE MI 1998 3 NOTICE: T hese standards do n ot purport to address safety issues, if any, ass o ciated with their use. It is the responsibility of t he user of these standards to establish appropriate safet…

SEMI G75-0698 © SEMI 1998 2

4.10 tensile break strength — The tensile force per

unit of original cross section of the sample at the point

of breakage.

4.11 tensile modulus — The ratio of stress to strain of

the sample below the yield point, in the elastic region of

the stress/strain curve.

NOTE: Plastic materials may not have a true elastic region in

the stress/strain curve or force/elongation curve. A tangent is

drawn to the maximum slope of the curve in order to

determine the modulus.

4.12 thermal decomposition temperature (base film

and adhesive) — The thermal decomposition

temperature is determined at 5% of the weight loss

when the tape is set to the thermal ramp at 10°

C/minute.

4.13 volume resistivity — The quotient of the voltage

gradient parallel to the current within the test piece

divided by the current density.

5 Significance

5.1 Ionic Impurities

5.1.1 Ionic contamination can adver sely affect the

reliability of semiconductor devices by causing leakage

currents and aluminum corrosion.

5.2 Adhesive Strength

5.2.1 Low adhesive strength may re sult in inner leads

movement of leadframe during the assembly and

packaging process which may result in low yield or

poor device reliability.

5.3 Peel Strength of Protective Film from Leadframe

Tape

5.3.1 If the peeling strength of prote ctive film from

leadframe tape varies in peeling strength, the taping

machines will not operate consistently.

5.4 Water Absorption

5.4.1 If the leadframe tapes absorb a n excessive

amount of water in storage, before or after packaging,

then reliability of devices made by these leadframes

may be affected. Current leakage and corrosion of

device metallization may occur.

5.5 Weight Loss

5.5.1 Weight loss may indicate that devices

manufactured with the leadframe tape may have

reliability problems due to the tape outgassing.

5.6 Shrinkage Factor

5.6.1 Excessive shrinkage at therma l processing may

cause the lead shift and wire bond problems for

automatic bonders.

5.7 Thermal Decomposition Temperature

5.7.1 The devices manufactured with leadframe tape

that decomposes at too low a temperature may have

lower reliability.

5.8 Coefficient of Thermal Expansion and Glass

Transition Temperature

5.8.1 Excessive expansion of the leadframe tape may

cause lead shift and/or lead lift and result in dislocated

bonds from automatic bonders.

5.9 Tensile Strength, Elongation, and Tensile Modulus

5.9.1 If the tensile strength, elongation, and tensile

modulus varies, the taping machines will not operate

consistently.

5.10 Volume and Surface Resistivity

5.10.1 Low volume and/or surface re sistivity is

indicative of potential leakage currents between

leadframe inner leads which can affect the function of

the device.

5.11 Dielectric Constant and Dissipation Factor

5.11.1 High dielectric constant mater ials used in

semiconductor packages may cause transmission

delays. High dielectric loss causes energy loss, which

leads to exothermic problems in semiconductor

packages.

5.12 Breakdown Strength

5.12.1 Very low breakdown strength may cause de-

vices to fail in use.

5.13 Leakage Current

5.13.1 A high leakage current betwee n leadframe

inner leads, which may be exacerbated due to high

moisture test conditions and impurities in the tape, may

result in poor device reliability.

6 Procedure

6.1 Procedures are detailed in the Test Methods

following this document.

7 Reporting Results

7.1 The sample size per lot and the reported items

shall be determined by agreement between user and

supplier.

7.2 The report shall contain the fo llowing information:

7.2.1 Leadframe Tape Material — M anufacturer, type,

and lot number.

7.2.2 Notification of acceptance or rejection.

SEMI G75-0698 © SEMI 19983

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’ 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 G75.1-0698 © SEMI 19981

SEMI G75.1-0698

TEST METHOD FOR MEASUREMENT OF IONIC IMPURITIES IN

LEADFRAME TAPE

1 Summary of Method

1.1 Ionic impurities are extracted from sample tape by

water at 100°C or 121°C and quantitatively analyzed by

ion chromatography and flame photometry or atomic

absorption spectrometry. The pH and electrical

conductivity of the extracted solutions are also

measured.

1.2 If sample tape needs the cure before the extraction,

vender should inform the customer of the necessity of

curing and report the impurity data after cure.

1.3 Ion chromatography is used to determine the

presence and concentration of the following ionic

species: Na

, NH4

, K

, NO

, Cl

, Br

, SO

, PO

1.4 Flame photometry or atomic absorption

spectrometry is used to determine the concentration of

and K

ions.

1.5 pH and conductivity measurements are also de-

scribed.

2 Referenced Documents

NOTE: As listed or revised, all documents cited shall be the

latest publications of adopted standards.

2.1 SEMI Standards

SEMI G29 — Test Method for Trace Contaminants in

Molding Compounds

SEMI G59 — Test Method for Measurement of Ionic

Contamination on Leadframe Interleafing and the

Contamination Transferred from the Interleafing to the

Leadframes

2.2 ASTM Standards

ASTM D 1125 — Standard Test Methods for Electrical

Conductivity and Resistivity of Water

ASTM D 1193 — Standard Specification for Reagent

Water

ASTM D 4327 — Standard Test Method for Anions in

Water by Ion Chromatography

ASTM E 70 — Standard Test Method for pH of

Aqueous Solutions with the Glass Electrode

2.3 JIS Specifications

1 American Society for Testing Materials, 100 Barr Harbor Drive,

West Conshohoken, PA 19428-2959

JIS K 0121 — General Rules for Atomic Absorption

Spectrochemical Analyses

JIS Z 8802 — Method for Determination of pH of

Aqueous Solutions

3 Interferences

3.1 All the sample preparations and measurements

must be carried out in clean containers which have been

washed in deionized water in order to reduce any

spurious readings.

3.2 Electrodes and syringes must be similarly cleaned

before each test.

3.3 Contamination from the sampling process may

also affect the results.

4 Equipment

4.1 Ion Extraction Vessels-Parr bomb with Teflon

liner.

4.2 Ion chromatograph for anion and cation analysis

(see SEMI G59).

4.3 Flame photometer or atomic absorption

spectrometer.

4.4 Standard solution preparation vessels, balance and

volumetric dispensers (see SEMI G29 and SEMI G59).

4.5 pH meter.

4.6 Microconductivity cell and meter.

5 Reagents and Materials

5.1 Deionized water, conductivity of less than 1.0 µ

S/cm at 25°C per ASTM D 1193.

5.2 Eluents and regenerants for specific

chromatograph columns prepared per chromatograph

equipment manufacturer’s recommendations so that the

water peak can be separated from the ionic peaks.

5.3 Compounds for Standard Solutions

5.3.1 Cations — NaCl, NH

Cl, KCl

5.3.2 Anions — NaCl, Na2HPO

•12H2O, NaBr,

NaNO

, K

NOTE: All compounds to be reagent grade.

2 Japanese Standards Association, 1-24, Akasaka 4 Chome, Minato-

ku, Tokyo, Japan