Adhesive for electronic component

1. An adhesive composition for a pre-applied underfill sealant comprising:

(a) a radical polymerizable monomer having one or more functional groups selected from the group consisting of vinyl group, maleimide group, acryloyl group, methacryloyl group and allyl group,

(b) a polymer having a polar group, wherein the polar group is selected from the group consisting of hydroxyl, carboxyl, (meth)acrylovl and epoxy group, and the polymer has a weight-average molecular weight in the range of 10,000 to 1,000,000,

(c) a filler having an average particle diameter of less than 1 μm, and

(d) a thermal radical initiator,

wherein the adhesive composition is in the form of a film having a thickness not less than 5 μm and not more than 100 μm.

2. The adhesive composition according to claim 1 , wherein said thermal radical initiator (d) is an organic peroxide.

3. The adhesive composition according to claim 1 , further comprising a support tape laminated on the adhesive composition.

4. A method for producing a film-shaped adhesive composition, comprising a step of applying the adhesive composition according to claim 1 on a supporting substrate, and B-staging the applied adhesive composition.

5. A wafer with an adhesive layer, comprising the adhesive composition according to claim 1 in a B-staged state and laminated on an element-formed face of a wafer.

6. The wafer with an adhesive layer according to claim 5 , further comprising a support tape laminated on the adhesive layer.

7. A method for producing a wafer with an adhesive layer, comprising a step of applying the adhesive composition according to claim 1 on an element-formed face of a wafer, and B-staging the applied adhesive composition.

8. A method for producing a wafer with an adhesive layer, comprising a step of laminating the film-shaped adhesive composition according to claim 1 on an element-formed face of a wafer.

9. A wiring board with an adhesive, comprising the adhesive composition according to claim 1 in a B-staged state and laminated on a wiring board.

10. A method for producing a wiring board with an adhesive, comprising a step of applying the adhesive composition according to claim 1 on a wiring board, and B-staging the applied adhesive composition.

11. An electronic device which is produced by using the adhesive composition according to claim 1 .