Composite metal column for mounting semiconductor device
AssigneeTexas Instruments Incorporated
InventorsJohn P. Tellkamp, Akira Matsunami
Life of this patent
Estimating the term…
Abstract
An integrated circuit chip 903, which has a plurality of pads 903b and non-reflowable contact members 1201 to be connected by reflow attachment to external parts. Each of these contact members 1201 has a height-to-diameter ratio and uniform diameter favorable for absorbing strain under thermo-mechanical stress. The members have a solderable surface 1202 on each end and a layer of reflowable material on each end. Each member is solder-attached (1204) at one end to a chip contact pad 903b, while the other end (1203) of each member is operable for reflow attachment to external parts.
Claims5
A method for forming connection members and assembling said members on the contact pads on a semiconductor device comprising the steps of:
- providing a metal sheet with a top surface and a bottom, having a core layer of a non-reflowable metal and a layer of reflowable material adherent to each surface, the thickness of said sheet determining the height of said connection members;
- providing a two-part die for guiding a stamping punch, each part having a structure to match the pattern of said contact pads;
- positioning and clamping said sheet between said die parts;
- providing a stamping punch having a plurality of stamping pins, the diameter of said pins determining the diameter of said connection members, said pins distributed to match said contact pad distribution;
- aligning said punch, said die having said sheet clamped between said parts and said semiconductor device so that each stamp pin is located over one of said contact pads;
- pressing said punch through said die and said sheet so that each stamping pin punches a connection member from said sheet, creating one connection member for each contact pad;
- bringing said members in surface contact with said pads;
- applying heat to said individual members and said device to melt said reflowable material between said members and said pads;
- and
- cooling the temperature below the reflow temperature whereby each member becomes firmly attached to its respective pad.
Dependencies are inferred from the claim text.