Adhesive of substituted oxirane or oxetane compound with silver-based, lead-free solder
View Patent ↗In accordance with the present invention, it has now been found that glycidyl epoxy resins containing substitution on the epoxide ring can be used with conventional epoxy curing agents and fluxing agents to produce underfill adhesives that are suitable for use with silver-based alloys. Owing to the structural similarity of the new materials to conventional epoxy resins, physical and material properties of the invention formulations are altered little, if at all, relative to products currently in use, and so are highly compatible with existing processes.
1. A combination of an adhesive composition and a silver-based, lead-free solder, comprising
(a) an adhesive composition comprising
(i) the combination of at least one substituted oxirane compound and at least one substituted oxetane compound, and one or more polymerizable co-reactants,
wherein said at least one substituted oxirane compound or substituted oxetane compound comprises the structure:
E-CH 2 -Q-X p —Y—Z m —Y n —X p -Q—CH 2 -E
wherein:
each E is independently an oxirane bearing 1, 2, or 3 additional substituents other than H or an oxetane bearing 1, 2, or 3 additional substituents other than H,
each Q is independently selected from the group consisting of —O— and —S—,
each X is optional, and when present, is independently selected from —C(O)— and —SO 2 —,
each Y is independently an optionally substituted hydrocarbylene,
Z is optional, and when present is selected from the group consisting of —O—, —C(O)—, —S—, —SO 2 —, hydrocarbylene and substituted hydrocarbylene, and combinations of any two or more thereof,
m=0 or 1,
n=0 or 1, and
each p is independently 0 or 1, and
(ii) optionally, a fluxing agent; and
(b) a silver-based, lead free solder.
2. The composition of claim 1 , wherein the hydrocarbylene of Y or Z is selected from the group consisting of alkylene, alkenylene, alkynylene, cycloalkylene, and arylene.
3. The composition of claim 2 , wherein arylene is phenylene or naphthylene.
4. The composition of claim 1 , wherein each Q is —O—.
5. The composition of claim 4 , wherein X is —C(O)—.
6. The composition of claim 4 , wherein each Y is —C 6 H 4 —.
7. The composition of claim 4 , wherein Z is —C(CH 3 ) 2 —.
8. The composition of claim 1 , wherein each of m and n is 0.
9. The composition of claim 1 , wherein each of m and n is 1.
10. The composition of claim 1 , wherein at least one E has the structure:
wherein:
each of R 1 -R 3 is independently selected from the group consisting of hydrogen, alkyl, substituted alkyl, aryl, and substituted aryl, provided, however, that at least one of R 1 -R 3 is not hydrogen.
11. The composition of claim 10 , wherein R 1 and R 3 are H and R 2 is —CH 3 .
12. The composition of claim 10 , wherein R 1 is H and each of R 2 and R 3 are —CH 3 .
13. The composition of claim 1 , wherein at least one E has the structure:
wherein:
R 4 is selected from the group consisting of alkyl, substituted alkyl, aryl, and substituted aryl.
14. The composition of claim 13 , wherein R 4 is —CH 3 .
15. The composition of claim 1 , wherein said co-reactants are epoxy, oxetane, carboxylic acid, anhydride, thiol, amine, or combinations of any two or more thereof.
16. The composition of claim 1 , wherein said co-reactants are epoxy.
17. The composition of claim 1 , further comprising one or more additional polymerizable components selected from the group consisting of maleimides, cyanate esters, vinyl ethers, (meth)acrylates, and styrenes.
18. The composition of claim 1 , further comprising at least one polymerization promoter, and optionally, a filler, toughening agent and/or plasticizer.
19. The composition of claim 1 , wherein reaction products of said composition are re-workable.
20. The composition of claim 19 , wherein reaction products of said composition are thermally reworkable.