ASTM F204-76(2018)

Standard Test Method for Surface Flaws in Tungsten Seal Rod and Wire

ABSTRACT
This test method establishes the apparatuses to be used, specimen preparation methods, and standard procedures for determining the presence of surface flaws in tungsten-seal rods and wires of random or cut lengths, and in the tungsten section of multiple-piece-through leads used in electronic devices, by means of examination of a glass bead sealed to the tungsten.
SCOPE
1.1 This test method covers the determination of the presence of surface flaws in tungsten-seal rod and wire of random or cut lengths, and in the tungsten section of multiple-piece-through leads used in electronic devices, by means of examination of a glass bead sealed to the tungsten.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 28-Feb-2018
• ICS: 21.140 - Seals, glands
• Technical Committee: F01 - Electronics
• Drafting Committee: F01.03 - Metallic Materials, Wire Bonding, and Flip Chip

Relations

• Replaces: ASTM F204-76(2013) - Standard Test Method for Surface Flaws in Tungsten Seal Rod and Wire
• Effective Date: 01-Mar-2018
• Referred By: ASTM F288-96(2019) - Standard Specification for Tungsten Wire for Electron Devices and Lamps
• Effective Date: 01-Mar-2018

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: F204 − 76 (Reapproved 2018)
Standard Test Method for
Surface Flaws in Tungsten Seal Rod and Wire
ThisstandardisissuedunderthefixeddesignationF204;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Apparatus
1.1 This test method covers the determination of the pres- 3.1 Beading Equipment—Suitable beading equipment ca-
ence of surface flaws in tungsten-seal rod and wire of random pable of producing glass-to-tungsten seals as prescribed in
or cut lengths, and in the tungsten section of multiple-piece- Section 4.
through leads used in electronic devices, by means of exami-
3.2 Microscope—Alow-power microscope capable of mag-
nation of a glass bead sealed to the tungsten.
nification up to 30 diameters, preferably of the binocular type.
1.2 The values stated in SI units are to be regarded as
3.3 Light Source— A suitable white light source, preferably
standard. No other units of measurement are included in this
diffuse for illumination of the bead under the microscope.
standard.
4. Preparation of Test Specimen
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the 4.1 The test specimen shall be a beaded tungsten rod
responsibility of the user of this standard to establish appro-
prepared in the following manner:
priate safety, health, and environmental practices and deter- 4.1.1 Clean the surface to be beaded in the usual manner
mine the applicability of regulatory limitations prior to use.
employed by the user of the tungsten.
1.4 This international standard was developed in accor- 4.1.2 Alternative Methods of Specimen Preparation—In
dance with internationally recognized principles on standard-
case of disagreement between the manufacturer and the
ization established in the Decision on Principles for the purchaser, substitute one of the following alternative methods
Development of International Standards, Guides and Recom-
of preparing the tungsten rod for that in 4.1.1.
mendations issued by the World Trade Organization Technical 4.1.2.1 Boilthetungstenfor2minina5 %solutionof27 %
Barriers to Trade (TBT) Committee. hydrogen peroxide. Pour off the hydrogen peroxide and rinse
the tungsten twice in distilled water. Dry rapidly with pure
2. Terminology alcohol or in an oven heated to 100°C.
4.1.2.2 Place the tungsten in a solution (20 weight %) of
2.1 Definitions:
sodium hydroxide or potassium hydroxide and pass sufficient
2.1.1 beaded length—the actual length through which a
electrical current through it to induce electrolytic action
glass-to-tungsten seal exists as evidenced by the color of the
sufficient to clean the specimen.
interface.
4.2 Bead the cleaned tungsten rod over the area to be
2.1.2 fault—a tungsten-glass seal in which a fissure, either
examined with glass, of the type and wall thickness commonly
delineated by a line of bubbles or in itself clearly discernible,
used for beading, to a length of not less than 5 mm bead length.
is observed when inspected as prescribed in this test method.
4.3 To permit examination of the gla
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