A redistribution layer (RDL) is an extra metal layer on an
integrated circuit
An integrated circuit (IC), also known as a microchip or simply chip, is a set of electronic circuits, consisting of various electronic components (such as transistors, resistors, and capacitors) and their interconnections. These components a ...
that makes its
I/O pads available in other locations of the chip, for better access to the pads where necessary.
When an integrated circuit is manufactured, it usually has a set of I/O pads that are
wirebonded to the pins of the package. A redistribution layer is an extra layer of wiring on the chip that enables bond out from different locations on the chip, making chip-to-chip bonding simpler. Another example of the use for RDL is for spreading the contact points around the
die so that
solder balls can be applied, and the
thermal stress
In mechanics and thermodynamics, thermal stress is mechanical stress created by any change in temperature
Temperature is a physical quantity that quantitatively expresses the attribute of hotness or coldness. Temperature is measurement, m ...
of mounting can be spread. The RDL is often made out of a
polyamide
A polyamide is a polymer with repeating units linked by amide bonds.
Polyamides occur both naturally and artificially. Examples of naturally occurring polyamides are proteins, such as wool and silk. Artificially made polyamides can be made throug ...
,
benzocyclobutene (BCB) or
polybenzoxazole (PBO) with copper plated on its surface.
See also
*
Semiconductor device fabrication
Semiconductor device fabrication is the process used to manufacture semiconductor devices, typically integrated circuits (ICs) such as microprocessors, microcontrollers, and memories (such as Random-access memory, RAM and flash memory). It is a ...
References
External links
Redistribution tutorial
Semiconductor device fabrication
Packaging (microfabrication)
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