Abstract: An electric circuit assembly and method provides direct bonding of a copper lead frame pattern (430) on a ceramic substrate (402), including the provision of numerous isolated lead frame segments of small size, without requiring individual oxidation nor placement of same on the substrate, and eliminating loss of alignment during fusing during direct bonding. The lead frame pattern (430) includes a plurality of lead frames (432) interconnected and held together by support bridges (434) therebetween. The support bridges (434) are designed to vaporize, open, retract and disappear during the direct bonding operation, resulting in direct bonded fusion of the copper lead frames (432) to the ceramic substrate (402), and eliminating any remnant of the support bridges (434).

Abstract: An electric circuit assembly (212) includes a ceramic tub (214) having a substrate floor (216) and an integral side wall (218) around the perimeter thereof and extending upwardly therefrom and having an integral lower wall (270) extending downwardly therefrom. The lower wall (270) is multi-partitioned and includes dividing wall portions (286, 288) providing electrical isolation and preventing sparking or voltage crossover between lead frames (220, 222, 224). The lower multi-partitioned wall also includes an outer peripheral portion (290) generally defining a chamber between the substrate (216) and a lower substrate (226) and enclosing the space between the substrates and encompassing recesses (274, 276, 278) defined in the lower surface of the upper substrate by central inner partitioned wall portions (286, 288, 292, 294). Copper lead frames (220, 222, 224) have pad portions (220a, 222a, 224a), received in respective recesses below respective apertures (240, 242, 244) through the upper substrate (216).

Abstract: An electric circuit assembly includes a copper pin (310) extending through aligned apertures (304, 314) in a directly bonded ceramic substrate (302) and copper lead frame (312), and directly bonded to the substrate (302). The pin (310) has an enlarged flange head (322) at one end, and is thermally deformed and enlarged at the other end (324) during the direct bonding. In another embodiment, one end (342) of a copper pin (340) extends out of an aperture (334) in a ceramic substrate (332) and slightly beyond the substrate surface (336). A lead frame (346) is directly bonded to the substrate surface (336) and droops around the protruding end (342) os the pin (340) and conforms thereto during the heating during the direct bonding. The lead frame (346) has a humped configuration over the aperture (334) in the substrate (332) and engages the protruding end (342) of the pin (340) and is deformed and raised thereby away from the substrate surface (336).

Abstract: A current sense circuit (100) includes a semiconductor power switch such as a MOSFET (102) having a source metallization contact pad (14) with a conductor jumper bond wire (106) directly connected thereto in the MOSFET module housing (104), which bond wire is connected to a source terminal lead frame within the module, which lead frame extends externally of the module for connection to a load (22) and load voltage (24). The current sense circuitry includes amplifier circuitry (150, 168) having first and second inputs (122, 124) connected to the source bond wire (106) at spaced points (126, 128) along the bond wire within the module housing (104) without insertion of additional series shunt resistance in the bond wire (106) between such points (126, 128), and sensing current flow through the bond wire (106) by sensing voltage between such points (126, 128) and amplifying such voltage.

Abstract: An electric circuit assembly (10) includes a ceramic substrate (14), a copper lead frame (20) having pad portions (22, 24, 26) directly bonded on the substrate, crimped portions (28, 30, 32) extending from the pad portions in a humped configuration above the substrate, and extension portions (34, 36, 38) extending from the crimped portions laterally beyond the substrate. The crimped portions prevent bonding of the extension portions to the substrate, to enable upward bending of the extension portions and crimped portions along bend lines (54) spaced laterally inwardly of the outer edge (18) of the substrate.

Abstract: An electrical circuit assembly (2) includes a heat sink (4), a ceramic substrate (6) on top of the heat sink (4), heat generating electrical components (8), including circuit elements (10) and lead frames (12), on top of the substrate. A threaded bolt (28) extends through aligned holes (22, 18, 16, 14) in the lead frame, substrate and heat sink and is electrically isolated from the lead frame and prevents short circuiting between the lead frame and the heat sink by a ceramic washer (24) having a lower annular portion (26) extending axially downwardly in the aligned holes around the bolt and having an upper radially extended shoulder flange (27) beneath an enlarged head (32) of the bolt.

Abstract: An electric circuit assembly (12) includes a ceramic tub (14) having a floor (16) and an integral side wall (18) around the perimeter thereof and extending upwardly therefrom. Copper lead frames (20, 22, 24), are directly and hermetically bonded to the bottom of the tub floor at apertures (40, 42, 44) therethrough. A semiconductor chip (38) is connected to the lead frames through the apertures in the floor of the tub. A top cover (36) is hermetically sealed to the top (32) of the side wall of the tub to close the tub and hermetically seal the semiconductor chip therein. A first copper ring (30) is directly bonded to the top of the side wall of the tub and a second copper ring (34) is directly bonded to the underside of the ceramic top cover, and the rings are subsequently welded to each other.

Abstract: An electric circuit assembly (10) is provided by a ceramic base substrate (14), a copper ground plane (20) directly bonded to the base substrate, an intermediate ceramic substrate (22) directly bonded to the ground plane, and a copper lead frame (24) having a pad portion (26) directly bonded to the intermediate substrate. The base substrate extends laterally beyond the ground plane and intermediate substrate. The lead frame has an extension portion (32) extending laterally beyond the intermediate substrate, ground plane and base substrate, and spaced above the base substrate by the thickness of the ground plane and intermediate substrate. The lead frame extension portion is bent upwardly from the pad portion along a bend line spaced laterally inwardly of the outer edge (18) of the base substrate.

Abstract: Heat sink cooling apparatus (4) includes a conduit (8) having an electrically conductive first portion (10) providing a first electrical terminal, an electrically conductive second portion (12) providing a second electrical terminal, and an electrically insulative intermediate portion (14) between and electrically isolating the first and second portions (10 and 12). The conduit (8) has an internal passage (16) receiving coolant (18) flowing therethrough including through the first and second portions (10 and 12) and the intermediate portion (14) therebetween. A heat generating electric current conducting component (6) is mounted on the first conduit portion and connected by an electrical conductor (26) to the second conduit portion (12) such that electric current flows through the component (6) and the conductor (26) between the first and second conduit portions (10 and 12) providing the main electrical terminals. The intermediate conduit portion (14) prevents a short circuit between the main terminals.

Abstract: An electric circuit assembly (10) includes a ceramic substrate (14), a copper lead frame (20) having pad portions (22, 24, 26) directly bonded on the substrate, crimped portions (28, 30, 32) extending from the pad portions in a humped configuration above the substrate, and extension portions (34, 36, 38) extending from the crimped portions laterally beyond the substrate. The crimped portions prevent bonding of the extension portions to the substrate, to enable upward bending of the extension portions and crimped portions along bend lines (54) spaced laterally inwardly of the outer edge (18) of the substrate.

Abstract: In a circuit assembly (36) having a semiconductor chip such as a MOSFET (12) mounted on a drain terminal lead frame (6) on a ceramic substrate (4), a combined source and gate return reference jumper wire (40) is connected between a current sense lead frame (52) and a combined gate return reference and current sense lead frame (38). The jumper wire has a first middle portion (42) connected to the source pad (14) of the MOSFET chip (12), and has a second middle portion 58 connected to the source terminal lead frame (8). Direct gate return referencing is provided, minimizing inductance in the gate return which is otherwise present when the gate return current path shares a portion of the source terminal current path. Direct current sensing is also provided, and the IR drop is sensed across the section of the wire jumper between the noted first and second middle portions (42and 58), without the need of an auxiliary resistor in series with the source terminal.

Abstract: Packaging structure is disclosed for three electrically isolated triacs (4,6,8) all within the same compact package (2). Plural sets of terminals are provided, each set having a pair of main terminals (15-16, 17-18, 19-20) and a gate terminal (39, 40, 41). One of the main terminals has a first substrate section (30, 31, 32) at a peripheral substrate edge (62) and a second substrate section (33, 34, 35) extending normally therefrom to an end portion (48, 49 50) disposed between substrate portions (42 and 24, 43 and 25, 44 and 26) of the gate terminal and the other main terminal, respectively. A power switching semiconductor component (4, 6, 8) is bonded to the end (48, 49, 50) of the extended substrate portion (33, 34, 35) of the one main terminial, which extended section has an open central section in which the gate terminal (39, 40, 41) is bonded to the substrate and isolated from the main terminals (15-16, 17-18, 19-20).

Abstract: In an electric circuit assembly (2) having conductive lead frames (8-10) directly bonded to an insulating substrate (6) by a eutectic, the lead frames are further subjected to a work hardening step (32, 34) to stiffen the lead frames and enable push-on fastener connection (12) to the lead frames without collapse thereof.

Abstract: A circuit package (2) includes a housing (10) having a chimney (20) extending downwardly through an upper epoxy coating material (16) into a lower thermally expansible soft silicon coating material (14) which covers heat generating electrical components (8) on a ceramic substrate (4). The soft silicon coating material is pliable and subject to thermal expansion. The epoxy coating material is substantially rigid and not subject to thermal expansion. The chimney provides a thermal expansion relief passage for the soft silicon coating material upon heating thereof by the electrical components, to prevent the ceramic substrate from being pushed away from the housing by the soft silicon coating material during thermal expansion thereof, and reduce undesirable forces against internal components.

Abstract: An electrical circuit assembly (2) includes a heat sink (4), ceramic substrates (6, 6a) on top of the heat sink (4), heat generating electrical components (8a), including electronic circuit elements (10,10a) and a plurality of flat planar connecting lead frames (12,12a, (14,14a and 16,16a) on top of the substrates (6,6a) and a printed circuit board (26) on top of the flat lead frames (12,12a 14,14a and 16,16a). The printed circuit board (26) has a conductive pattern (28) on its underside electrically engaging and laying flat along the top planar surface of the flat lead frames (12,12a, 14,14a and 16,16a). A plurality of deformable rivets (52, 54, 56 and 58) extend downwardly through respective apertures (60, 62, 64 and 66) in the printed circuit board (26) and through respective apertures (68, 70, 72 and 74) in the heat sink.

Abstract: An isolation transformer is provided by a primary conductor formed on an insulating layer above a secondary conductor formed on a chip therebelow, with flux lines coupling between the primary and secondary conductors to provide transformer action through the insulating layer therebetween. The primary is formed by a serpentine pattern having a plurality of parallel strips transverse to a plurality of parallel strips forming the secondary conductor. The secondary conductor may be formed on an extra insulating layer on the chip substrate.

Abstract: A copper lead frame (16) has an aperture (18) through which a molybdenum layer (20) extends to directly contact a ceramic substrate (8) therebelow. A semiconductor chip (2) is mounted on the molybdenum layer (20). Thermal conductivity is improved because of the reduced number of thermal path conduction layers between the semiconductor chip (2) and the ceramic substrate (8). The arrangement also enables the chip-expansion-matched thermal conductor (20) to contact the semiconductor chip (2) and match expansion therewith.

Abstract: A circuit package 2 is provided for heat dissipating power semiconductors and the like. Circuit means 10, including lead frames 12 and power conditioning components 13, is mounted on an electrically insulating thermally conductive substrate 4 and covered by an electrically insulating housing 6. Power lead frames 14 extend integrally externally of the housing 6 and have external portions 22 bent laterally across the to surface of the housing 6 to cooperate with terminal connection means 28 there below in the top wall 24 of the housing 6. Internal connection means 50 is provided for selectively connecting a peripheral power lead frame portion 46 to a central portion 52 of circuit means 10 and insulatively bypassing designated portions 54 of circuit means 10 therebetween. In one embodiment, circuit package 2 is provided in combination with an external printed circuit board 40 extending across the top surface 24 of the housing and connected to control lead frames 18 and power lead frames 14.

Abstract: A compact circuit package includes a housing providing a cavity for containing heat generating electrical components. A ceramic substrate is mounted to close the cavity. The package is adapted to be mounted in heat transferring relationship with a heat sink. The bottom surface of the compact circuit package is provided with a self-contained chamber containing a supply of grease. The chamber is defined by the package bottom surface and a bubble of plastic film which overlies the substrate and which is removable sealed to the package around the periphery of the substrate. In this form, the compact circuit package can be transported and stored until ready for use. When the package is ready to be mounted to a heat sink, pressure such as by a finger is applied to the top surface of the bubble film to thereby spreadingly apply the grease to the surface of the substrate.

Abstract: The compact circuit package (11) includes an insulating housing (12) providing a circuit retaining cavity (19) substantially surrounded by a pair of spaced side walls (15, 16) each terminating at a first rim (21, 22) and a second pair of spaced side walls (17, 18) each terminating at a second rim (24, 25). Each of the side walls provides an abutment (28, 31, 34) which limits the depth of entry of a electrically insulating, heat conducting substrate (30) into the cavity (19). Outer portions (44, 45) of a first pair of side walls rims (21, 22) are removed such as by a sander (46) to form a clamping surface (48) which includes an outer surface (42) of substrate (30) and reduced end portions (49, 50) of the pair of the side wall rims (21, 22) to permit increased substantial clamping pressures to a substantially planar external heat dissipating object (51) without damaging the substrate (30) and the side walls (15, 16, 17 18).