InFORMS®
Reinforced Indium and Solder Alloy Fabrications
Introduction
InFORMS® are patented fabrications in which braided, woven, or
random-fiber metal or non-metal substrate materials are sandwiched
between layers of pure indium or solder alloy. In the manufacturing
process, material from the surface layers passes through the
substrate matrix to cold weld where the metals meet within
the matrix. The process produces a reinforced indium or solder
fabrication with improved strength and handling characteristics.
The layers may also be adhered to the substrate without cold welding
at the interface so the substrate can flex to accommodate shear or
thermally-induced forces. Another option, would be to adhere an outer
indium or alloy layer to only one side of a substrate.
For solder applications, flux may be incorporated within the matrix or
applied as a coating.
After the laminating process is complete, parts are cut or punched
into discs, washers, rectangles and other shapes to suit specific
application requirements. Strip materials can also be provided for
custom sizing by the user.
Product Advantages
Informs offer dramatically improved handling when compared to
conventional solder alloy or indium sheet, foil, ribbon or large
preform materials. InFORMS also offer increased tensile and
compressive strength via the substrate materials while retaining
the unique attributes of the outer layer metal (e.g. the softness,
ductility, and other advantages of indium).
Applications
InFORMS provide engineers with an enhanced material for the
development of new, or the improvement of existing, applications.
They can be used in cryogenic or vacuum seals, EMI and RFI shielding,
ground straps, stand-offs, thermal mismatch devices or backplane
assembly washers. While a number of metals may be used, indium
should be considered in many applications because of its unique
attributes. For example, Indium readily wets glass, quartz, and glazed ceramics. When compared to conventional solders, indium-based
solders significantly reduce scavenging and leaching of gold and other precious metals.
Substrates and Outer Layer Metals
InFORMS can be produced from a wide range of metal and non-metal
substrates depending on the needs of the application. InFORMS have
been successfully produced using tin plated copper shielding mesh,
stainless steel mesh, and even woven and random-fiber fiberglass cloth.
Please contact our Technical Support Engineers if you would like us to
work with you to develop samples for experimentation, including special
substrate materials, layer thicknesses, or outer layer metallizations.
In applications where the metal meets in the substrate matrix, metals
used on outer layers may be dissimilar as long as they are compatible
with each other. Where the application does not require cold welding
of the outer layers, the layers may also be dissimilar. In either case,
compatibility with the substrate material must be considered in
applications development. Most compatibility issues are documented
in solder technical guides. However, if in question, it’s always a good
idea to contact Indium Corporation for advice. When solder alloys are
specified, published temperature guidelines are applicable.
Dimensional Specifications
InFORMS are produced in sheet form and can be cut or punched into
large unique shapes for applications such as cryogenic or vacuum
seals, or into small preforms for tasks such as component assembly.
Dimensional tolerances can be held to those normally specified for
standard solder preforms, but may vary depending on the part size,
thickness, substrate, and outer layer materials. Please contact us if
you have special requirements.
Summary
InFORMS add handling capability to soft and ductile indium and solder
alloys. They also strengthen and yet retain, the unique attributes of
the metals selected for the outer layers. InFORMS offer countless
opportunities for solving difficult application problems.
