Adhesive bonding composition and method of use
A polymerizable composition includes at least one monomer, a photoinitiator capable of initiating polymerization of the monomer when exposed to light, and a phosphor capable of producing light when exposed to radiation (typically X-rays). The material is particularly suitable for bonding components at ambient temperature in situations where the bond joint is not accessible to an external light source. An associated method includes: placing a polymerizable adhesive composition, including a photoinitiator and energy converting material, such as a down-converting phosphor, in contact with at least two components to be bonded to form an assembly; and, irradiating the assembly with radiation at a first wavelength, capable of conversion (down-conversion by the phosphor) to a second wavelength capable of activating the photoinitiator, to prepare items such as inkjet cartridges, wafer-to-wafer assemblies, semiconductors, integrated circuits, and the like.
1. A curable adhesive composition comprising:
an organic vehicle comprising at least one polymerizable monomer, wherein the viscosity of said organic vehicle is suitable for dispensing through an automated dispenser onto a selected substrate;
at least one photo-initiator responsive to a selected wavelength of light; and,
at least one energy converting material selected to emit said wavelength of light when exposed to a selected imparted radiation, wherein the at least one energy converting material is a downconverting material.
2. The curable adhesive of claim 1 , wherein the imparted radiation is an ionizing radiation.
3. The curable adhesive of claim 2 , wherein the ionizing radiation is X-rays.
4. The curable adhesive of claim 1 wherein said organic vehicle comprises a monomer forming a thermoset resin.
5. The curable adhesive of claim 4 , wherein said thermoset resin is selected from the group consisting of: acrylics, phenolics, urethanes, epoxies, styrenes, and silicones.
6. The curable adhesive of claim 1 , wherein said at least one photoinitiator is selected from the group consisting of: benzoin ethers, benzil ketals, α-dialkoxyacetophenones, α-aminoalkylphenones, acylphosphine oxides, benzophenones/amines, thioxanthones/amines, and titanocenes.
7. The curable adhesive of claim 1 , wherein said wavelength of light is in the UV range and said ionizing radiation comprises X-rays.
8. The curable adhesive of claim 1 , wherein said downconverting material comprises dispersed inorganic particulates selected from the group consisting of: metal oxides; metal sulfides; doped metal oxides; and mixed metal chalcogenides.
9. The curable adhesive of claim 1 , wherein the viscosity of said organic vehicle is suitable for printing onto a selected substrate through a mask.
10. The curable adhesive of claim 1 , wherein said adhesive is photo-patternable.
11. The curable adhesive of claim 1 , further comprising inorganic particulates selected from the group consisting of: metals and metal alloys, ceramics and dielectrics, and metal-coated polymers.
12. The curable adhesive of claim 1 , further comprising an organic component selected from the group consisting of: solvents, viscosity modifiers, surfactants, dispersants, and plasticizers.
13. The curable adhesive of claim 1 , wherein the at least one photo-initiator and the at least one energy converting material are chemically tethered to one another.
14. A cured adhesive formed from the curable adhesive of claim 1 .
15. The cured adhesive of claim 14 , wherein the cured adhesive is in the form of a film.
16. The cured adhesive of claim 15 , wherein the cured adhesive in the form of a film is partially cured.
17. The cured adhesive of claim 15 , wherein the film has anisotropic properties.