1. Field of the Invention
The present invention relates to silane adducts used as coupling agents which adhere inorganics like metal, glass or ceramic to organic adhesives like epoxy resin, polyimide resin, polyimide-siloxane resin, and siloxane resin used in the field of semiconductor package of Board-On-Chip (BOC), and Chip Scale Package (CSP) installed on electronic devices, cellular phone and computers, etc. More specifically, the present invention relates to silane adducts having a relatively higher adhesive strength as expressed formula 1, and manufacturing method thereof.

wherein X is a dehydrogenated form selected from one of epoxy compounds, amino compounds, and bisphenolics, and R1 is a organoalkyl group, which is one of the functional group selected among glycidyloxypropyl group, 2-(3,4-epoxycyclohexyl)ethyl- group, 3-acryloxypropyl group, 3-methacryloxypropyl group, amino-propyl group, 3-[2-(2-aminoethylamino)ethylamino]propyl group, N-methylaminopropyl group, N-phenylaminopropyl group, N,N-dimethyl-3-aminopropyl group, mercapto-propyl group, cyano-propyl group, and isocyanato-propyl group.
2. Description of the Background Art
Conventional silane coupling agent as expressed formula 2 is used as coupling agents which adhered inorganics like metal, glass or ceramic to organic adhesives like epoxy resin, polyimide resin, polyimide-siloxane resin, and siloxane resin used in the field of semiconductor package of Board-On-Chip (BOC), and Chip Scale Package (CSP) installed on electronic devices, cellular phone, computer, semiconductor material like BOC, and CSP

wherein, R is methyl or ethyl group. R1 is selected from one of glycidyloxypropyl group, 2-(3,4-epoxycyclohexyl)ethyl group, 3-acryloxypropyl group, 3-methacryloxypropyl group, amino-propyl group, 3-[2-(2-aminoethylamino)ethylamino]propyl group, N-methylaminopropyl group, N-phenylaminopropyl group, N,N-dimethyl-3-aminopropyl group, mercapto-propyl group, cyano-propyl group, and isocyanato-propyl group, which has a reactivity or a compatibility with polymeric materials.
More details, for the purpose that the silane coupling agent as expressed formula 2 couples inorganic material to organic materials, the RO— group of the conventional silane coupling agent as expressed formula 2 must be transformed into silanol group, —SiOH, as expressed formula 3 by hydrolysis process as shown in reaction 1.
Silanol group of formula 3 formed by hydrolysis chemically reacted to inorganic materials, and R1 group can be chemically coupled to other organic materials. From the reaction, the bond between organic adhesives and inorganics will be strengthened.(RO)3SiR1+H2O→(HO)3SiR1+3R—OH  [Reaction 1]

wherein R and R1 are the same as those of formula 2, and R—OH is organic by-product with low molecule. Because R—OH is a volatile organic compound, it is desirable to minimize the by-product for safety and environmental cause.
In general, there are three methods of Solution, Dry-blend, and Integral blend to adapt the conventional silane compounds and then to bond between organic adhesive and inorganics. The details are shown below:
1) Solution Method:
It is used to make compounds of formula 3 with silanol group through hydrolysis of RO— group as shown in reaction 1 by adding silane coupling agent to alcohol/water co-solvent. This process takes an hour and it is very important to properly control pH of the solution.
2) Dry Blend Method:
It is a method that silane compounds without hydrolysis are directly added or silane compounds blended with solvent are added into mineral fillers, before impregnating the fillers to resin.
However, it has the disadvantage that the silane compound is not uniformly wetted over the filler.
3) Integral Blend Method:
This method is to directly add the silane coupling agent without treatment by hydrolysis to a polymeric phase etc. and then to diffuse the silane coupling agent on the surface of fillers uniformly dispersed in polymer resin. This method is used in the case that the above two methods are difficult to adopt. Its result is, however, less effective than the above two methods 1) and 2) which are directly wetted on surface of fillers.
In the case where the silane coupling agent is applied to the organic die attach adhesive so that chips as inorganic material are connected with substrates as electrical path in Board-On-Chip (BOC) or Chip-Scale-Package (CSP) of semiconductor, the solution method and the dry blend method can not be used because the surfaces of the chip and the substrate cannot be directly treated with silane coupling agent. For that purpose, the integral blend method directly adding the silane coupling agent to the adhesive should be used.
However, if the integral blend method is used in order that the general silane coupling agent is added into the adhesive applied to BOC or CSP, R—OH group generated by hydrolysis forms void on the interface between the die attach adhesive and metal or chip. The void trapped on the interface may give rise to incomplete wetting, which inevitably leads to a decrease of the adhesive strength when external thermal or mechanical stress is applied thereto. Therefore, the adhesive with the conventional silane coupling agent is very difficult to use for adhesion of package like BOC and CSP for semiconductors.