Solderless test interface for a semiconductor device package
AssigneeTexas Instruments Incorporated
InventorEdward H. Olsen
Life of this patent
Estimating the term…
Abstract
A solderless test interface (10) includes a thin, flexible, electrically insulative sheet (20) having metal plated through-holes (24) formed in the pattern of the external ball contacts (54) of a semiconductor device (14). The termini (26, 30) of the holes (24) on the surface of the sheet (20) are also plated. The metal (40) is coated with a soft metal (42) which will cold-flow under force. The sheet is inserted between the ball contacts (54) and a test board (18). Force is applied to the test board and/or the device to engage and deform the soft metal (42) at the hole termini (26, 30) by its engagement with the balls (54) and pads (16) on the test board. The deformation ensures a low resistance electrical path between the balls and the pads during testing of the device.
Claims5
A solderless test interface for establishing a temporary, very low electrical resistance connection between external contacts of a semiconductor device package and conductive pads of a test board, which comprises:
- a thin, planar, flexible, electrically insulative substrate having apertures therethrough, the pattern of the aperture termini on one side of the substrate being congruent with the pattern of the contacts, and the pattern of the aperture termini on the other side of the substrate being congruent with the pattern of the conductive pads, the substrate being insertable between the facing contacts and pads, when the device package and the test board are opposed, in order to align the respective termini groups with the contacts and the pads;
- a first, electrically continuous thin layer of a highly conductive metal on the wall of each aperture and on both surfaces of the substrate surrounding the termini of each aperture;
- and
- a second, electrically conductive, soft metal layer on at least the termini-surrounding portions of the first layer, the soft metal experiencing cold flow deformation when force is applied to such portions by the contacts and the pads while the substrate is inserted between the device and the board as they are urged together to establish a very low electrical resistance path between the balls and the pads through the deformed portions of the second layer and through the first layer.
Apparatus for establishing a temporary, very low electrical resistance connection between the balls of a BGA semiconductor device and conductive pads of a test board, which comprises:
- a thin, planar, flexible, electrically insulative substrate having a plurality of apertures therethrough, the pattern of the terminus of each aperture on one side of the substrate being congruent with the pattern of the balls on the BGA and the pattern of the terminus of each aperture on the other side of the substrate being congruent with the pattern of the conductive pads on the test board, the substrate being insertable between the BGA device and the test board;
- an electrically continuous thin coating of a highly conductive metal on the wall of each aperture and on both surfaces of the substrate surrounding the termini of each aperture wall;
- and
- a soft metal layer on the coatings, the soft metal layer on each terminus-surrounding coating experiencing cold flow when force is applied between the layers covering opposed annular coatings when the substrate is inserted between the device and the board as they are urged together, to establish a very low resistance through the coating between the balls and the pads.
A method of establishing a temporary, very low electrical resistance connection between external contacts of a semiconductor device package and conductive pads of a test board, which comprises:
- inserting a thin, planar, flexible, electrically insulative substrate having apertures therethrough, between the facing contacts and pads, when the device package and the test board are opposed;
- the pattern of the aperture termini on one side of the substrate being congruent with the pattern of the contacts, and the pattern of the aperture termini on the other side of the substrate being congruent with the pattern of the conductive pads;
- a first, electrically continuous thin layer of a highly conductive metal being deposited on the wall of each aperture and on both surfaces of the substrate surrounding the termini of each aperture;
- a second, electrically conductive, soft metal layer being deposited on at least the termini-surrounding portions of the first layer;
- aligning the respective termini groups with the contacts and the pads;
- and
- urging the package and the test board together with sufficient force to deform the soft metal by cold flow deformation effected by the contacts and the pads thereagainst to establish a very low electrical resistance path between the balls and the pads through the deformed portions of the second layer and through the first layer.
A method of establishing a temporary, very low electrical resistance connection between the balls of a BGA semiconductor device and opposed conductive pads of a test board, which comprises:
- inserting between the device and the board a flexible, thin, electrically insulative substrate having therethrough plural apertures each aligned with a respective ball-pad pair and carrying on the aperture walls and on the substrate surfaces surrounding the aperture termini a soft metal layer which experiences cold flow in those regions of the layer surrounding the aperture termini when a force is applied to such regions;
- and
- applying sufficient force to the device and the board to effect sufficient cold flow of the regions engaged by the balls and the pads to effect a very low resistance electrical path therebetween.
A method of making a solderless test interface for establishing a temporary, very low electrical resistance connection between external contacts of a semiconductor device package and conductive pads of a test board, which comprises:
- forming apertures through a thin, planar, flexible, electrically insulative substrate, the pattern of the aperture termini on one side of the substrate being congruent with the pattern of the contacts, and the pattern of the aperture termini on the other side of the substrate being congruent with the pattern of the conductive pads, the substrate being insertable between the facing contacts and pads, when the device package and the test board are opposed, in order to align the respective termini groups with the contacts and the pads;
- depositing a first, electrically continuous thin layer of a highly conductive metal on the wall of each aperture and on both surfaces of the substrate surrounding the termini of each aperture;
- and
- depositing a second, electrically conductive, soft metal layer on at least the termini-surrounding portions of the first layer, the soft metal experiencing cold flow deformation when force is applied to such portions by the contacts and the pads while the substrate is inserted between the device and the board as they are urged together to establish a very low electrical resistance path between the balls and the pads through the deformed portions of the second layer and through the first layer.
Dependencies are inferred from the claim text.