Method of making multilayered circuitized substrate assembly
View Patent ↗A method of making a multilayered circuitized substrate assembly which includes bonding at least two circuitized substrates each including at least one layer of high temperature dielectric material, one of these layers in turn including at least one thru-hole therein having therein a quantity of a a low temperature conductive paste, the paste including an organic binder component and at least one metallic component. The flakes of the metallic component are sintered during the bonding to form a conductive path through the dielectric of one of the substrates.
1. A method of making a multilayered circuitized substrate assembly, said method comprising:
providing a first circuitized substrate including at least one high temperature dielectric layer having first and second opposing surfaces and at least one opening within said at least one high temperature dielectric layer, extending from said opposing surface to said second opposing surface;
positioning a quantity of low temperature conductive paste within said at least one opening of said first circuitized substrate, said low temperature conductive paste including an organic binder component and at least one metallic component including a plurality of flakes; and
bonding a second circuitized substrate including at least one high temperature dielectric layer to said first circuitized substrate by lamination over a time period of approximately 300 minutes and at a pressure within the range of from about 1700 PSI to about 2300 PSI, whereby said flakes within said low temperature conductive paste are sintered during said lamination process and are of sufficient density to form at least one electrical path through said paste, from said first opposing surface to said second opposing surface.
2. The method of claim 1 wherein, during said lamination, the lamination temperature is raised from an ambient temperature to a first predetermined temperature over a first predetermined time period and maintained at said first predetermined temperature for a second predetermined time period, following which said lamination temperature is lowered to a third predetermined temperature over a third predetermined time period and then further lowered to a fourth predetermined temperature over a fourth predetermined time period.
3. The method of claim 2 wherein said first predetermined time period is about 45 minutes, said first predetermined temperature is about 364.4 degrees C., said second predetermined time period is about 125 minutes, said third predetermined temperature is about 260 degrees C., said third predetermined time period is about 100 minutes, said fourth predetermined temperature is about 176.7 degrees C. and said fourth predetermined time period is the remaining minutes of said time period of approximately 300 minutes.
4. The method of claim 2 wherein said lamination temperature is lowered to an ambient temperature following said time period of approximately 300 minutes.