Thermally reworkable binders for flip-chip devices
AssigneeShell Oil Company
InventorsShridhar R. Iyer, Pui Kwan Wong
Life of this patent
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Abstract
A semiconductor device is attached to a supporting substrate by a plurality of solder connections that extend from the supporting substrate to the semiconductor device and the gap between the supporting substrate and the semiconductor device is filled with a reworkable composition comprising: (a) a thermally reworkable crosslinked resin produced by reacting at least one dienophile having a functionality greater than one and at least one 2,5-dialkyl substituted furan-containing polymer, and (b) at least one filler present in an amount from about 25 to about 75 percent by weight based upon the amount of components (a) and (b). Such a process provides a readily reworkable semiconductor assembly.
Claims30
An encapsulated flip chip assembly comprising:
- a supporting substrate;
- at least one semiconductor device attached to said supporting substrate by means of a plurality of solder connections that extend from said supporting substrate to form a gap between said supporting substrate and said semiconductor device;
- and
- a thermally reworkable binder filling said gap, said thermally reworkable binder comprising:
- (a) a thermally reworkable crosslinked resin produced by reacting at least one dienophile having a functionality greater than one and at least one 2,5-dialkyl substituted furan-containing polymer, and
- (b) at least one filler present in an amount from about 25 to about 75 percent by weight based upon the amount of components (a) and (b) thereby providing an assembly.
A process of providing an encapsulated flip chip assembly comprising the steps of:
- attaching at least one semiconductor device to a supporting substrate by a plurality of solder connections that extend from the supporting substrate to said semiconductor device to form a gap between said supporting substrate and said semiconductor device,
- filling said gap with a thermally reworkable flip chip binder comprising:
- (a) a thermally reworkable crosslinked resin produced by reacting at least one dienophile having a functionality greater than one and at least one 2,5-dialkyl substituted furan-containing polymer, and
- (b) at least one filler present in an amount from about 25 to about 75 percent by weight based upon the amount of components (a) and (b) thereby providing a flip chip assembly.
A method of reworking an encapsulated flip chip assembly comprising the steps of:
- heating the encapsulated flip chip assembly comprising at least one semiconductor device attached to a supporting substrate by a plurality of solder connections that extend from the supporting substrate to the semiconductor device to form a gap between said supporting substrate and said semiconductor device, and a thermally reworkable flip chip binder filling said gap, said thermally reworkable flip chip binder comprising
- (a) a thermally reworkable crosslinked resin produced by reacting at least one dienophile having a functionality greater than one and at least one 2,5-dialkyl substituted furan-containing polymer, and
- (b) at least one filler present in an amount from about 25 to about 75 percent by weight based upon the amount of components (a) and (b), at a temperature which is sufficiently high to melt or soften the solder connections and to convert the thermally reworkable composition into a liquid thereby providing a liquid composition,
- removing the semiconductor device from the supporting substrate providing a device-removed substrate.
Dependencies are inferred from the claim text.