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| Application |
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This
semiconductor device is mainly used as a switch
in power electronics converters. The command signal
being the voltage is applied between gate and
source terminal.
The device generates almost
no loss (little heat generation), which lends
the power supply fast response, excellent linearity,
and high efficiency.
Example:
MOSFET (Metal Oxide Silicon Field Effect Transistor)
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| Product
Design |
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There
are several different designs for a Power Leadframe.
Typical for them is a big & thick Heatsink,
which is mainly needed to dissipate the heat and
as well to carry the silicon chip. The lead count
starts with two & goes up to 7 Leads. The
most common product stamped & delivered to
the Semiconductor Industry is a TO220 in dual
gauge form.
Example: TO220 standard & TO220 IDF
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| Raw
Materials |
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In
order to give the best properties to a Power Leadframe
(high conductivity & easy dissipation of heat),
a pure Copper is used as base material, which
has minimum 99.8% of Cu and only little impurities
like Iron, Nickel or Phosphorous. Today’s
market requires two different material forms:
Dual gauge material and Single gauge material
Dual
gauge material is a material, which has two different
thicknesses. The thin material area is created
either by milling, by hammering or by a rolling
process
Example:
Dual gauge material milled
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Single
gauge material has the same thickness all over
the Leadframe, same as IC or Discrete products.
Beside
the material form, there are varieties on the
plating requirements. Till today, most Power Leadframe
has Nickel-Nickel Phosphorous plating. This plating
process is done before the stamping (called pre-plating),
which leads to bare Copper edges on the finished
product.
The
current market trend is moving towards the direction
of bare Copper, which means no plating at all.
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