ASTM F44-16

Standard Specification for Metallized Surfaces on Ceramic

ABSTRACT
This specification covers requirements for powdered refractory metal coatings produced with or without additives. These coatings are applied to ceramic bodies in order to join ceramic bodies to metals or to other metallized ceramics by means of brazing or soldering. Included in this specification are requirements for a secondary metallic layer which is usually applied over the refractory metal layer. Two levels of quality for uniformity of metallizing are discussed, Level A and Level B. These levels discuss conditions and requirements needed in order to accept the uniformity of metallizing. Thickness of metallizing shall be measured using a metallurgical microscope. A polished cross-section that is perpendicular to the metallized surfaced is measured. The particles in the metallized layer must be sintered in order to form a dense matrix when viewed in cross section at 400 times. This cross section will indicate the extent of threedimensional sintering. A torque peel test and a tension test shall be performed in order to determine the bond strength of brazed metallized ceramics. Vacuum tightness of the brazed metallized ceramics shall also be determined.
SCOPE
1.1 This specification covers requirements for powdered refractory metal coatings produced with or without additives. These coatings are applied to ceramic bodies in order to join ceramic bodies to metals or to other metallized ceramics by means of brazing or soldering. Included in this specification are requirements for a secondary metallic layer which is usually applied over the refractory metal layer.  
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

General Information

• Status: Historical
• Publication Date: 30-Apr-2016
• ICS: 25.220.40 - Metallic coatings
• Technical Committee: F01 - Electronics
• Drafting Committee: F01.03 - Metallic Materials, Wire Bonding, and Flip Chip

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: F44 −16
Standard Specification for
1
Metallized Surfaces on Ceramic
ThisstandardisissuedunderthefixeddesignationF44;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 4. Ordering Information
4.1 The manufacturer and purchaser shall agree upon spe-
1.1 This specification covers requirements for powdered
cific quality levels as outlined in the following sections:
refractory metal coatings produced with or without additives.
4.1.1 Uniformity of metallizing (Section 5),
These coatings are applied to ceramic bodies in order to join
4.1.2 Thickness of metallizing (Section 6),
ceramic bodies to metals or to other metallized ceramics by
4.1.3 Secondary metal layer on the metallizing (Section 9),
meansofbrazingorsoldering.Includedinthisspecificationare
4.1.4 Values for bond strength (Section 10), and
requirements for a secondary metallic layer which is usually
4.1.5 Vacuum tightness of brazed metallized ceramic as-
applied over the refractory metal layer.
semblies (dependent on allowable use of manufacturer’s prod-
1.2 Thevaluesstatedininch-poundunitsaretoberegarded
uct) (Section 11).
as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only
5. Uniformity of Metallizing
and are not considered standard.
5.1 Either of the following two levels of quality may be
agreed upon between manufacturer and purchaser, depending
2. Referenced Documents
upon end use, seal area, and geometry.
2
2.1 ASTM Standards:
5.2 Level A—Less Demanding Application:
E3Guide for Preparation of Metallographic Specimens
5.2.1 Thin areas where the ceramic substrate can usually be
F19Test Method for Tension and Vacuum Testing Metal-
seen without magnification through the metallizing will be
lized Ceramic Seals
acceptable only if all of the following conditions are met:
5.2.1.1 There are no more than two such areas on any one
3. Terminology
coated band, spot, or pattern detail.
3.1 Definitions of Terms Specific to This Standard: 5.2.1.2 Theirextremitiesarenocloserthan10%ofthetotal
band length to each other.
3.1.1 ceramics—as referred to in this specification are
5.2.1.3 They are no wider than 10% of the width of the
understood to be inorganic, nonmetallic materials, the major
band but not exceeding 1 mm.
phase of which must be crystalline. A glassy intercrystalline
5.2.1.4 Theircumulativelengthdoesnotexceed25%ofthe
matrix may be present as one of the minor phases.
total band length.
3.1.2 metallizing— on a ceramic, is a process whereby a
5.2.2 Defects such as brush marks, screen marks, marks in
sinteredmatrixofmetalparticlesfirmlyadherestotheceramic.
themetallizingleftbyforeignmattersuchaslint,dust,etc.,and
3.1.3 refractory metals—those metals with melting points
pits or blisters, will be acceptable if they meet the four
equaltoorhigherthanthatofchromium.Therefore,thisgroup conditions outlined in 5.2.1.1 through 5.2.1.4. Such defects
includes chromium, columbium, molybdenum, rhenium,
will also be acceptable if their raised edges do not interfere
tantalum, and tungsten. with proper assembly of the joint.
5.2.3 Projections on metallized surfaces, such as oversized
particlesoragglomerateswillbeobjectionableiftheyinterfere
with assembly.
1
This specification is under the jurisdiction of ASTM Committee F01 on
5.2.4 Continuous coatings over sharp edges or corners with
Electronics and is the direct responsibility of Subcommittee F01.03 on Metallic
1
Materials, Wire Bonding, and Flip Chip.
a radius less than ⁄32 in. (0.8 mm) will not be required unless
Current edition approved May 1, 2016. Published May 2016. Originally
by specific agreement between manufacturer and purchaser.
approved in 1968. Last previous edition approved in 2011 as F44-95 (2011). DOI:
10.1520/F0044-16.
5.3 Level B—Demanding Application:
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
5.3.1 Thin areas will be unacceptable where the ceramic
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
substrate can be seen through the metallizing when examined
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. at 40× magnification.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
F44−16
5.3.2 Defects through which the underlying ceramic can be 9.4 Manufacturer and purchaser shall agree upon the layer
observed, such as brush or screen marks, marks left by foreign thickness, including maximum and minimum thickness limits.
mattersuchas
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: F44 − 95 (Reapproved 2011) F44 − 16
Standard Specification for
1
Metallized Surfaces on Ceramic
This standard is issued under the fixed designation F44; the number immediately following the designation indicates the year of original
adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This specification covers requirements for powdered refractory metal coatings produced with or without additives. These
coatings are applied to ceramic bodies in order to join ceramic bodies to metals or to other metallized ceramics by means of brazing
or soldering. Included in this specification are requirements for a secondary metallic layer which is usually applied over the
refractory metal layer.
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered standard.
1.3 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information
only.
2. Referenced Documents
2
2.1 ASTM Standards:
E3 Guide for Preparation of Metallographic Specimens
F19 Test Method for Tension and Vacuum Testing Metallized Ceramic Seals
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 ceramics—as referred to in this specification are understood to be inorganic, nonmetallic materials, the major phase of
which must be crystalline. A glassy intercrystalline matrix may be present as one of the minor phases.
3.1.2 metallizing— on a ceramic, is a process whereby a sintered matrix of metal particles firmly adheres to the ceramic.
3.1.3 refractory metals—those metals with melting points equal to or higher than that of chromium. Therefore, this group
includes chromium, columbium, molybdenum, rhenium, tantalum, and tungsten.
4. Ordering Information
4.1 The manufacturer and purchaser shall agree upon specific quality levels as outlined in the following sections:
4.1.1 Uniformity of metallizing (Section 5),
4.1.2 Thickness of metallizing (Section 6),
4.1.3 Secondary metal layer on the metallizing (Section 9),
4.1.4 Values for bond strength (Section 10), and
4.1.5 Vacuum tightness of brazed metallized ceramic assemblies (dependent on allowable use of manufacturer’s product)
(Section 11).
5. Uniformity of Metallizing
5.1 Either of the following two levels of quality may be agreed upon between manufacturer and purchaser, depending upon end
use, seal area, and geometry.
5.2 Level A—Less Demanding Application:
1
This specification is under the jurisdiction of ASTM Committee F01 on Electronics and is the direct responsibility of Subcommittee F01.03 on Metallic
MaterialsMaterials, Wire Bonding, and Flip Chip.
Current edition approved June 1, 2011May 1, 2016. Published June 2011May 2016. Originally approved in 1968. Last previous edition approved in 20062011 as F44-95
(2006).(2011). DOI: 10.1520/F0044-95R11.10.1520/F0044-16.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
F44 − 16
5.2.1 Thin areas where the ceramic substrate can usually be seen without magnification through the metallizing will be
acceptable only if all of the following conditions are met:
5.2.1.1 There are no more than two such areas on any one coated band, spot, or pattern detail.
5.2.1.2 Their extremities are no closer than 10 % of the total band length to each other.
5.2.1.3 They are no wider than 10 % of the width of the band but not exceeding 1 mm.
5.2.1.4 Their cumulative length does not exceed 25 % of the total band length.
5.2.2 Defects such as brush marks, screen marks, marks in the metallizing left by foreign matter such as lint, dust, etc., and pits
or blisters, will be acceptable if they meet the four conditions outlined in 5.2.1.1 through 5.2.1.4. Such defects will also be
acceptable if their raised edges do not interfere with proper assembly of the joint.
5.2.3 Projections on metallized surfaces, such as oversized particles or agglomerates will be objectionable if they interfere w
...