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Product Data Sheet
Solder Preforms
Introduction
Solder Preforms are used in a variety of applications that
require precise amounts of solder.
Preforms come in standard shapes such as squares,
rectangles, washers and discs. Typical sizes range from
.010" (.254mm) up to 2" (50.8mm). Smaller and larger
sizes, as well as custom shapes, are also available.
Dimensions can be held to tight tolerances to assure
volume accuracy.
Selecting Alloys
A wide assortment of alloys is available in liquidus
temperatures that range from 47°C to 1063°C. Alloys can
be indium–contained, gold-contained, lead–free, fusible or
standard tin–lead, as well as many others.
1. Alloy selection should be based on strength and other
required physical properties, as well as the preferred
soldering temperature and the operating
temperature of the device being soldered. A general rule
is to select an alloy that melts at least 50°C higher than
the operational temperature of the part being soldered.
2. Next, consider the materials being soldered and what
solder is most compatible with them. For example,
tin–based solders will scavenge the gold from gold-plated Selecting Dimensions
parts, forming brittle intermetallics, so indium-based The location of the solder joint and the volume of solder
solders are generally recommended in these cases. needed will determine the size and shape of the preform.
3. Metals and alloys have different characteristics that can Once the flat dimensions (diameter, length, width) have
affect the ease with which they can be made into different been determined, the thickness can be adjusted to achieve
shapes and thicknesses. It is important to consider the the desired volume of solder. Generally, for through–hole
shape of the final preform in the alloy selection process. connections, add 10–20% to the calculated volume for a good
fillet. For pad to pad joints, figure about 5% less surface area
4. The operating environment of the completed assembly is than the pad.
also an important consideration for alloy selection. Will
it operate in very high or very low temperatures, or be Each Solder Preform should have a burr tolerance specified.
subjected to vibration? If so, you need to select an alloy You should stay as close to standard tolerances as possible
that will stand up to these conditions. to avoid adding cost and lead time to your preforms.
Our Application Engineers will work with you to determine Indium Corporation has an extensive library of sizes and
the best alloy for your application. shapes from which you can choose, or we can create a
set–up specifically for your application. Using an existing
preform size can eliminate the additional time associated
with creating a new set–up.
OVER—>
Form No. 97702 R3
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Solder Preforms
Packaging and Storage Technical and Customer
Solder Preforms come in a variety of packaging options, Support
including tape and reel. To minimize excessive handling, Indium Corporation’s internationally experienced engineers
and exposure to air and subsequent oxidation, Solder provide in-depth technical assistance to our customers.
Preforms should be packaged according to the quantity Thoroughly knowledgeable in all facets of Material Science
used during a typical work shift. as it applies to the electronics and semiconductor sectors,
Technical Support Engineers provide expert advice in solder
Store in the original container, closed securely, in 55% properties, alloy compatibility and selection of solder
RH or less and at temperatures less than 22°C. Solder preforms, wire, ribbon and paste. Indium Corporation’s
Preforms can also be stored in an inert atmosphere, such Technical Support engineers provide Rapid Response to all
as a nitrogen dry box. technical inquiries.
Shelf Life Material Safety Data Sheet
The shelf life of solder preforms is dependent on the alloy
The MSDS for this product can be found online at
composition. Pb-free alloys, and alloys with lead content of
http://www.indium.com/techlibrary/msds.php
less than 70%, have a shelf life of 1-year from the date of
manufacture (DOM). Alloys with lead content >70% have a
shelf life of 6-months from the DOM.
Dimensional Specification Recommendations
Width/length or diameter: Typical Tolerances
Up to .100" (2.54mm) ±.002"(± .051mm)
Over .100" (2.54mm) ± .005" (± .127mm)
Thickness:
Up to .001" (.025mm) ± .0002" (.005mm)
.001" (.025mm) to .002" (.050mm) ± .0003" (.0076mm)
> .002" (.050mm) to .010" (.254mm) ± .0005" (.0127mm)
> .010" (.254mm) to .020" (.508mm) ± .0010" (.0254mm)
> .020" (.508mm) to .050" (1.27mm) ± .0025" (.0635mm)
> .050" (1.27mm) ± 5%
Burr Tolerances (Discs, Squares & Rectangles):
≤.050" (1.27mm) .002" (.050mm)
>.050" (1.27mmm) to .500" (12.7mm) .003" (.076mm)
>.500" (12.7mm) .005" (.127mm)
Burr Tolerances (Washers & Frames):
≤.100" (2.54mm) .003" (.076mm)
When thickness ≥ 2/3 of I.D. .005" (.127mm)
Also available: solder ribbon and foil, solder wire, solder paste, solder spheres, solder fluxes, solder ingot, and other solder
fabrications.
This product data sheet is provided for general information only. It is not intended, described which are sold subject exclusively to written warranties and limitations
and shall not be construed, to warrant or guarantee the performance of the products thereon included in product packaging and invoices.
