Method for bonding high heat conductive insulating resin
Provided is a method for bonding a high heat conductive insulating resin, by which the high heat conductive insulating resin can be bonded to a heat sink without deteriorating insulating characteristics and heat conducting characteristics. The method includes: a fixing step of fixing the heat sink by means of a jig having a vacuuming function; a placing step of placing the heat sink fixed with the jig on a sheet-like high heat conductive insulating resin previously bonded to a cooler and making a hermetically closed space; and a bonding step of having a bonding section between the heat sink and the sheet-like high heat conductive insulating resin under a negative pressure by depressurizing the hermetically closed space, heating the sheet-like high heat conductive insulating resin, and bonding the sheet-like high heat conductive insulating resin to the heat sink.
1. A method of bonding a high heat conductive insulating resin to a heat sink on which a semiconductor element is soldered so that the high heat conductive insulating resin is interposed between a heat sink and a cooler, the heat sink being to be provided in a power module, the method comprising:
a fixing step of fixing the heat sink with a hollow jig;
a placing step of placing the heat sink fixed with the hollow jig onto a sheet-like high heat conductive insulating resin bonded to the cooler in advance, to create a hermetically closed space; and
a bonding step of reducing pressure in the hermetically closed space to create a negative pressure around bonded portions of the heat sink and the sheet-like high heat conductive insulating resin and heating the sheet-like high heat conductive insulating resin to bond the sheet-like high heat conductive insulating resin to the heat sink, wherein
the fixing step includes horizontally fixing the heat sink with the hollow jig to hold the heat sink between internal surfaces of the hollow jig,
the placing step includes making the hollow jig adsorb the cooler through an opening formed in an end of the hollow jig to create the hermetically closed space defined by the heat sink, the cooler, and the hollow jig, and
the bonding step includes evacuating air from the hermetically closed space through a hole formed in the internal surfaces of the hollow jig to create a negative pressure around the bonded portions.
2. The method of bonding high heat conductive insulating resin according to claim 1 , wherein a surface of the heat sink to be bonded to the resin is formed with a taper in a peripheral edge portion.