Electrically conductive adhesive composition, connection structure, solar battery module, and method for producing same

1. An electrically conductive adhesive composition, comprising:

electrically conductive particles containing a metal of which melting point is 220° C. or less;

a thermosetting resin; and

a thermal cationic polymerization initiator,

wherein a combination ratio of the content of components of the electrically conductive adhesive composition other than the electrically conductive particles to the content of the electrically conductive particles is 5/95 to 50/50 in terms of the solid content ratio by mass.

2. The electrically conductive adhesive composition according to claim 1 , wherein the metal of the electrically conductive particles contains at least one selected from the group consisting of bismuth, indium, tin, and zinc.

3. The electrically conductive adhesive composition according to claim 1 , further comprising a flux activator.

4. The electrically conductive adhesive composition according to claim 3 , wherein the flux activator has a hydroxyl group and a carboxyl group.

5. The electrically conductive adhesive composition according to claim 1 , wherein the thermosetting resin contains an epoxy resin.

6. The electrically conductive adhesive composition according to claim 1 , wherein the thermal cationic polymerization initiator releases at least one selected from the group consisting of an inorganic ion containing an antimony atom, an inorganic acid ion containing a phosphorus atom, and an organic acid ion containing a boron atom, by heating.

7. The electrically conductive adhesive composition according to claim 1 , wherein a reaction start temperature of the thermosetting resin and the thermal cationic polymerization initiator is from 30 to 200° C.

8. The electrically conductive adhesive composition according to claim 1 used for electrically connecting an electrode of a solar battery cell and a wiring member.

9. The electrically conductive adhesive composition according to claim 1 , wherein the combination ratio of the content of components of the electrically conductive adhesive composition other than the electrically conductive particles to the content of the electrically conductive particles is 30/70 or less in terms of the solid content ratio by mass.

10. The electrically conductive adhesive composition according to claim 1 , wherein the combination ratio of the content of components of the electrically conductive adhesive composition other than the electrically conductive particles to the content of the electrically conductive particles is 10/90 to 30/70 in terms of the solid content ratio by mass.

11. The electrically conductive adhesive composition according to claim 1 , wherein the content of the thermosetting resin in the electrically conductive adhesive composition is 40% by mass or less.

12. The electrically conductive adhesive composition according to claim 1 , wherein the thermal cationic polymerization initiator comprises at least one salt selected from the group consisting of sulfonium salts, thiophenium salts, thiolanium salts, benzylanimonium salts, pyridinium salts, hydrazinium salts, carboxylic acid esters, sulfonic acid esters, amine imides, diazonium salts, iodonium salts, and phosphonium salts.

13. The electrically conductive adhesive composition according to claim 1 , wherein the content of the thermal cationic polymerization initiator is 0.01 parts by mass or more and more relative to 100 parts by mass of the thermosetting resin.

14. The electrically conductive adhesive composition according to claim 1 , wherein the content of the thermal cationic polymerization initiator is 0.1 parts by mass or more and more relative to 100 parts by mass of the thermosetting resin.

15. A connection structure, comprising:

a solar battery cell, and

a wiring member electrically connected with an electrode of the solar battery cell via the electrically conductive adhesive composition according to claim 1 or a cured product thereof.

16. A method for producing a solar battery module, comprising:

a step of arranging an electrode of a solar battery cell and a wiring member so as to face each other via the electrically conductive adhesive composition according to claim 1 ;

a step of laminating encapsulants on a light receiving surface side of the solar battery cell and on a back surface side opposite to the light receiving surface;

a step of laminating a glass member on the encapsulant at the light receiving surface side of the solar battery cell;

a step of laminating a protective film on the encapsulant at the back surface side of the solar battery cell; and

a step of heating the laminate having the glass member and the protective film to electrically connect the electrode of the solar battery cell and the wiring member and also to encapsulate the solar battery cell.

17. A solar battery module, comprising:

a solar battery cell;

a wiring member electrically connected to an electrode of the solar battery cell via the electrically conductive adhesive composition according to claim 1 or a cured product thereof;

encapsulants laminated each on a light receiving surface side of the solar battery cell and a back surface side opposite to the light receiving surface;

a glass member laminated on the encapsulant at the light receiving surface side of the solar battery cell; and

a protective film laminated on the encapsulant at the back surface side of the solar battery cell.