Nickel Alloys for Electronics - Nickel Institute

131 Pages·2002·0.75 MB·English

NiDI

Nickel
Development
Institute
Nickel
Alloys for
Electronics
A Nickel Development Institute
Reference Book Series N° 11 002
1988
NiDI
Nickel
Development
Institute
Nickel Development Institute (NiDI)
is the market development and
applications research organization of
the primary nickel industry. NiDl was
incorporated and organized in 1984. Its
headquarters are in Toronto, Canada.
NiDI's objective is sustained growth in
the consumption of nickel. Through a
network of a dedicated permanent staff
and key international consultants and
project contractors, NiDl carries out
market development activities, market
exploration, and applications-oriented
technical research relevant to the
achievement of its objective around the
world. It provides technical service to
nickel consumers and others concerned
with nickel, nickel alloys and their uses.
NiDI's principal marketing efforts are
directed toward the United States,
Western Europe, Japan and the newly
industrializing nations in Latin America,
the Pacific rim and the Indian subconti-
nent … those countries having the
greatest current consumption of nickel
and those having the greatest potential
for growth.
NiDI's information services are
available to designers, specifiers, and
educators as well as to nickel users.
Enquiries are welcomed from architects,
engineers, specification writers, and
others responsible for selection of
materials for manufacturing and
construction. NiDl cooperates with
colleges and universities by furnishing
relevant information and material for
engineering, materials science, and
industrial design education.
T
he material presented herein has
been prepared for the general informa-
tion of the reader and should not be
used or relied upon for specific applica-
tions without first securing competent
advice.
While the material is believed to be
technically correct, NiDl, its members,
staff, and consultants do not represent
or warrant its suitability for any general
or specific use and assume no liability
or responsibility of any kind in
connection with the information herein.
Drawings and/or photographs of
equipment, machinery, and products
are for illustrative purposes only, and
their inclusion does not constitute
or imply any endorsement of the items
or of the companies that manufacture
or distribute them.
Foreword
Reliability, freedom from maintenance costs,
longer service and minimum production
rejects have become increasingly important to
designers and manufacturers of electronic and
electrical equipment.
In civilian communications and computers,
military equipment and industrial controls,
nickel alloys provide the combinations of
characteristics and properties that warrant
their review whenever new designs or design
modifications are being considered.
Nickel Alloys for Electronics is intended to
provide information that will be directly ap-
plicable to engineers and designers in evaluat-
ing and applying the nickel alloys that are
most useful to the electronics industry. The
Nickel Development Institute (NiDI) gratefully
acknowledges the cooperation of the many
companies who have contributed information
and background data.
The materials included in this reference book
are based on generic alloys that have industry
specifications and Unified Numbering System
(UNS) numbers. Proprietary alloys and
manufacturers thereof are not included.
Table of Contents
Page No.
Semiconductor Packaging, Lead Frame and Glass Sealing Alloys
42 Alloy (K94100)................................................................................................1
F 15 Alloy (K94610)............................................................................................7
426 Alloy (K94760)............................................................................................10
46 Alloy (K94600)..............................................................................................13
52 Alloy (N14052)..............................................................................................16
Reference Data on Non-Metallic Materials.................................................................19
Minimum Expansion Alloy
Invar (K93600)...................................................................................................20
Nickel Beryllium (N03360)...........................................................................................23
Nickel
Nickel 200, 201, 205, 233, 270/290
(N02200, N02201, N02205, N02233, N02270/N02290)................................25
Copper-Base Connector and Spring Alloys
Copper Alloy C72500........................................................................................29
Copper Alloy C76200........................................................................................33
Copper Alloy C77000 .......................................................................................37
Spinodal Alloy
Copper Alloy C72900........................................................................................40
Stainless Steel Alloys AISI 301 and 304.....................................................................46
Nickel Electroplating.....................................................................................................49
Standards and Specifications......................................................................................62

Note—Numbers in parentheses are UNS (Unified Numbering System) Numbers; Copper
Development Association (CDA) and UNS Numbers for Copper-Base Alloys are identical.
42 Alloy*
Nickel and iron-nickel alloys were the Superior bend properties
original commercial semiconductor
at the temper used for
packaging metals. 42 Alloy lead frames
lead frames
continue to be used widely for high-
reliability ceramic Cer-DIP and plastic- Important in making conven-
packaged devices where these advan- tional 90° as well as J-bends.
tages are important:
Closest possible match to
thermal expansion of
Worldwide availability
alumina,
There are no patents on 42
Alloy and it is made everywhere beryllia and
semiconductor devices are vitreous glass
manufactured and packaged.
Extremely important in avoiding
cracks and breaks in soldered joints
Intrinsically superior
(Fig. 3).
strength and stiffness
Plateability
The much higher yield strength
and modulus of elasticity of 42 42 Alloy strip can be plated,
Alloy is important in minimizing striped or spot-plated with nickel,
bent leads, especially in automatic copper or lead-tin solder as well as
insertion (Fig. 1). gold or silver.
High softening and stress Weldability
relaxation temperatures Iron-nickel alloys are welded
readily by spot, projection, seam,
Strength and stiffness are main-
stitch, flash and other resistance
tained completely during exposure
and fusion processes. Alloy 42 is
to soldering, burn-in and other
also adaptable to ultrasonic and
manufacturing steps where ex-
thermocompression bonding and
posure to elevated temperatures is
electron-beam and laser welding.
possible (Fig. 2).
Cladding
Higher hardness at
Composite strip can be pro-
temper used
duced by cladding or inlaying 42
This is reflected in improved Alloy with copper, aluminum, gold
lead frame strip surface. or silver to obtain combinations of
the best properties of two or more
No intermetallic
alloys or metals, and to reduce
compounds costs.

that can be harmful to
These characteristics add up to the use
solderability
of 42 Alloy wherever resistance to heat,
High strength levels are moisture or aggressive environments is
developed through cold work encountered, and where long life and
alone. high reliability are called for. Properties of
42 Alloy are shown in Table 1.
*UNS K94100
1
Thermal Management in
Semiconductor Devices
and Printed Circuit Board
Assemblies
Limiting junction and average die
temperatures in microelectronic devices
and assemblies require consideration of
the chip and board designs, component
densities and external cooling systems.
These design factors plus the bulk
thermal conductivity of the ceramic or
epoxy package usually have more effect
than the thermal conductivity of the lead
frame material alone.
Thermal test boards and systems are
now widely used to test new device and
board designs and should be used to
determine whether the difference be-
tween the thermal conductivity of a 42
Alloy lead frame and a copper-base
frame is significant.
The high reliability and the superior
mechanical properties of 42 Alloy should
not be overlooked simply because the
thermal conductivity of the material is
not as high as the copper-base alloys.
2
Fig 1 Comparative yield strength levels of
42 Alloy vs C19400 at several tempers

3
Fig 2 Stress relaxation of high-strength
lead-frame alloys as measured by resistance to
softening [strip thickness 0.254 mm (0.010 in.)]
4
Fig 3 Linear thermal expansion of 42 Alloy,
99.5% beryllia and 94% alumina vs temperature

5