EP0337448A2 — Semiconductor device having a metal stem

Claim 1

Independent Claim 209 words

A semiconductor device of the type in which a metal stem (1) is superposed over the undersurface of a printed circuit board (5) over the upper surface of which are defined wiring patterns (4) being extended radially and outwardly from their starting ends at the center portion of the upper surface of said board (5); the upper portion of each of pins (7) inserted into through holes (1a,5a) of said board (5) and said stem (1), respectively, in alignment with each other, and said each lead pin (7) is connected to its corresponding end of said wiring patterns (4) on the upper surface of the board (5) through a connecting member (9) such as solder; and the upper and peripheral portions of said board (5) are covered with a metal shell (10): characterized in that the outer ends of said wiring patterns (4) defined over the upper surface of said board (5) so as to extend radially and outwardly, are located in the vicinity of the upper openings of said through holes (1a,5a) which are formed through said printed circuit board (5) and into which are inserted said lead pins (7), and said outer ends are absent at the positions of the outer sides from said through holes (1a,5a).

Claim 2

Dependent Claim 209 words

A semiconductor device of the type in which a metal stem (1) is superposed over the undersurface of a printed circuit board (5) over the upper surface of which are defined wiring patterns (4) being extended radially and outwardly from their starting ends at the center portion of the upper surface of said board (5); the upper portion of each of pins (7) inserted into through holes (1a,5a) of said board (5) and said stem (1), respectively, in alignment with each other, and said each lead pin (7) is connected to its corresponding end of said wiring patterns (4) on the upper surface of the board (5) through a connecting member (9) such as solder; and the upper and peripheral portions of said board (5) are covered with a metal shell (10): characterized in that the outer ends of said wiring patterns (4) defined over the upper surface of said board (5) so as to extend radially and outwardly, are located in the vicinity of the upper openings of said through holes (1a,5a) which are formed through said printed circuit board (5) and into which are inserted said lead pins (7), and said outer ends are absent at the positions of the outer sides from said through holes (1a,5a).

Claim 3

Dependent Claim 277 words

A semiconductor device comprising a metal stem (1), as a package substrate, a semiconductor chip (3) which is mounted on a heat sink (2) arranged to the stem (1), a printed circuit board (5) being superposed on the stem (1) and having wiring patterns (4) which are connected to a plurality of input and output terminals of the chip (3) at their starting ends through bonding wires (6), a plurality of lead pins (7) being connected to the corresponding outer ends of the patterns (4) and projecting downward through the stem (1), and a metal shell (10) fitted to the upper surface of the stem (1) so that the chip (3), wires (6) and the board (5) are covered; wherein the outermost ends of said wiring patterns (4) which are formed on said board (5) and connected to the outermost rows and columns of said lead pins (7), are formed in the manner of being confined to the inner position of the outermost rows and columns through holes (1a,5a) of the board (5) for said outermost lead pins (7); and before said semiconductor device is accomplished, all the starting ends at the center of the wiring patterns (4) are connected to each other and formed to a center portion wiring layer (11) so as to electrically short-circuit said wiring patterns (4) for gold plating in order to connect said starting end with said bonding wires (6), and after said device is accomplished, said center portion wiring layer (11) is cut off my means of blanking out the predetermined size and shape such that the connected portion of said wiring layer (11) is left in the predetermined size.

Claim 4

Dependent Claim 277 words

A semiconductor device comprising a metal stem (1), as a package substrate, a semiconductor chip (3) which is mounted on a heat sink (2) arranged to the stem (1), a printed circuit board (5) being superposed on the stem (1) and having wiring patterns (4) which are connected to a plurality of input and output terminals of the chip (3) at their starting ends through bonding wires (6), a plurality of lead pins (7) being connected to the corresponding outer ends of the patterns (4) and projecting downward through the stem (1), and a metal shell (10) fitted to the upper surface of the stem (1) so that the chip (3), wires (6) and the board (5) are covered; wherein the outermost ends of said wiring patterns (4) which are formed on said board (5) and connected to the outermost rows and columns of said lead pins (7), are formed in the manner of being confined to the inner position of the outermost rows and columns through holes (1a,5a) of the board (5) for said outermost lead pins (7); and before said semiconductor device is accomplished, all the starting ends at the center of the wiring patterns (4) are connected to each other and formed to a center portion wiring layer (11) so as to electrically short-circuit said wiring patterns (4) for gold plating in order to connect said starting end with said bonding wires (6), and after said device is accomplished, said center portion wiring layer (11) is cut off my means of blanking out the predetermined size and shape such that the connected portion of said wiring layer (11) is left in the predetermined size.

Claim 5

Dependent Claim 115 words

A semiconductor device according to claim 2; the upper end portions of said plurality of lead pins (7) are electrically connected to said outer ends of the wiring patterns (4) corresponding to the several lead pins (7) by means of a connecting member (9) such as solder; said printed circuit board (5) consists of a plastic film having wiring of copper (Cu) on its upper surface; said bonding wires (6) connected to said starting ends of said wiring patterns (4) by gold plating are made of aluminum (Al), and said wires (6) are connected to bonding pads which are arranged at the outer peripheral portion of said semiconductor chip (3) as input and output terminals.

Claim 6

Dependent Claim 63 words

A semiconductor device according to claim 2; said plurality of lead pins (7) are inserted into a plurality of through holes (1a,5a) bored at the predetermined portions of the metal stem (1) and printed circuit board (5) corresponding to said lead pins (7), and each insulation member (8) such as glass is filled between each lead pin (7) and each through hole (1a,5a).

Claim 7

Independent Claim 259 words

A method for producing a semiconductor device which is constituted in that a semiconductor chip is mounted on a heat sink provided to a metal stem; a printed circuit board including wiring patterns, which have central starting ends connected with bonding pads as input and output terminals of said semiconductor chip through bonding wires and outer ends of said patterns formed radially and connected to a plurality of lead pins projecting from undersurface of the stem, is superposed on the upper surface of the metal stem; a metal shell is fitted to the metal stem so as to cover said chip, said wires and said board: wherein said printed circuit board of the semiconductor device is made up through; the first step in which said wiring patterns are formed such that starting ends are connected each other at the center portion corresponding to arrangement position of said chip so as to form a central portion patterning wiring layer, and outer ends of said patterns are located within the outermost through holes of said stem and board corresponding to the outermost lead pins; the second step in which the predetermined current supply causes said central portion patterning wiring layer to be electrically short-circuited in order to plate it with gold so that an electrical connection between said wiring patterns and bonding wires for connecting said chip is stabilized; and the third step in which after said board is plated with gold, said central portion patterning wiring layer is cut off in the predetermined shape from said wiring patterns by blanking.

Claim 8

Independent Claim 259 words

A method for producing a semiconductor device which is constituted in that a semiconductor chip is mounted on a heat sink provided to a metal stem; a printed circuit board including wiring patterns, which have central starting ends connected with bonding pads as input and output terminals of said semiconductor chip through bonding wires and outer ends of said patterns formed radially and connected to a plurality of lead pins projecting from undersurface of the stem, is superposed on the upper surface of the metal stem; a metal shell is fitted to the metal stem so as to cover said chip, said wires and said board: wherein said printed circuit board of the semiconductor device is made up through; the first step in which said wiring patterns are formed such that starting ends are connected each other at the center portion corresponding to arrangement position of said chip so as to form a central portion patterning wiring layer, and outer ends of said patterns are located within the outermost through holes of said stem and board corresponding to the outermost lead pins; the second step in which the predetermined current supply causes said central portion patterning wiring layer to be electrically short-circuited in order to plate it with gold so that an electrical connection between said wiring patterns and bonding wires for connecting said chip is stabilized; and the third step in which after said board is plated with gold, said central portion patterning wiring layer is cut off in the predetermined shape from said wiring patterns by blanking.

Claim 9

Dependent Claim 55 words

A method for producing a semiconductor device according to claim 5; said wiring pattern formed in the first step consists of a plastic film on which the predetermined pattern is formed by copper (Cu), and said bonding wires which is electrically connected to said wiring patterns in the second step are formed by aluminum (Al).

Semiconductor device having a metal stem

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