Electrical device having improved lead frame and thermally stable connection arrangement and method

Claim 2

An electrical device (component/housing) having an improved lead frame, comprising: an electrical device comprising a main body having an associated horizontal plane, a geometric central point in the plane, and insulating wall portions; and a lead frame bonded to said insulating wall portions of the body and comprising a plurality of at least 5 electrical leads generally positioned about said central point and formed of flat sheet stock having a predetermined thickness, each of said leads having an emerging portion extending from said insulating wall portions of said body and connected by an intermediate flexible portion to an end lead portion to be bonded to another structure, said intermediate portion having orthogonal length and width dimensions and a thickness corresponding to said sheet stock thickness, said width dimension being measured parallel to said horizontal plane, said intermediate portion extending along its length dimension between said emerging and end lead portions in a general direction inclined with respect to said horizontal plane, wherein the improvement comprises each of said intermediate lead portions being oriented toward said central point so as to maximize absorption of stresses, by said intermediate portion, which stresses are radially directed between said central point and said end lead portion.

Claim 3

An electrical device according to claim 1 wherein each of said intermediate portions extend substantially perpendicular with respect to said horizontal plane.

Claim 4

An electrical device according to claim 2 wherein each of said end portions of said leads includes a planar portion extending parallel to said horizontal plane.

Claim 5

An electrical device according to claim 3 wherein said main body has a generally rectangular shape with major and minor axes parallel to said horizontal plane and a thickness dimension perpendicular to said horizontal plane and wherein at least one of said leads is position adjacent a corner of said body.

Claim 6

An electrical device according to claim 1 wherein said main body is a molded plastic body.

Claim 7

An electrical device (component/housing) having an improved lead frame, comprising: an electrical device comprising a main body having an associated horizontal plane, a geometric central point in the plane, and insulating wall portions; and a lead frame bonded to said insulating wall portions of said body and comprising a plurality of at least 5 electrical leads generally positioned about said central point and formed of flat sheet stock having a predetermined thickness, each of said leads having an emerging portion extending from said insulating wall portions of said body and connected by an intermediate flexible planar portion to an end lead portion to be bonded to another structure, said intermediate portion having orthogonal length and width dimensions and a thickness corresponding to said sheet stock thickness, said width dimension being measured parallel to said horizontal plane, said intermediate portion extending along its length dimension between said emerging and end lead portions in a direction inclined with respect to said horizontal plane, wherein the improvement comprises each of said intermediate lead portions being oriented such that for a vertical projection of said lead onto said horizontal plane, said width dimension of said intermediate portion is substantially perpendicular to a radial line in said horizontal plane drawn from said geometric central point toward the projection, in said horizontal plane, of said end lead portion connected to said intermediate portion, whereby after the leads are bonded to another structure, thermal expansion stresses which may act on the leads and/or the bonds of the leads to the other structure are minimized due to the orientation of the intermediate lead portions

Claim 8

An electrical device (component/housing) having an improved lead frame, comprising: an electrical device comprising a main body having an associated horizontal plane, a geometric central point in the plane, and insulating wall portions; and a lead frame bonded to said insulating wall portions of said body and comprising a plurality of at least 5 electrical leads generally positioned about said central point and formed of flat sheet stock having a predetermined thickness, each of said leads having an emerging portion extending from said insulating wall portions of said body and connected by an intermediate flexible planar portion to an end lead portion to be bonded to another structure, said intermediate portion having orthogonal length and width dimensions and a thickness corresponding to said sheet stock thickness, said width dimension being measured parallel to said horizontal plane, said intermediate portion extending along its length dimension between said emerging and end lead portions in a direction inclined with respect to said horizontal plane, wherein the improvement comprises each of said intermediate lead portions being oriented such that for a vertical projection of said lead onto said horizontal plane, said width dimension of said intermediate portion is substantially perpendicular to a radial line in said horizontal plane drawn from said geometric central point toward the projection, in said horizontal plane, of said end lead portion connected to said intermediate portion, whereby after the leads are bonded to another structure, thermal expansion stresses which may act on the leads and/or the bonds of the leads to the other structure are minimized due to the orientation of the intermediate lead portions

Claim 9

An electrical device according to claim 6 wherein each of said emerging portions comprises a planar portion extending from said body, parallel to said horizontal plane, to said intermediate lead portion.

Claim 10

An electrical device according to claim 7 wherein each of said intermediate portions extend substantially perpendicular with respect to said horizontal plane.

Claim 11

An electrical device according to claim 8 wherein each of said end portions of said leads includes a planar portion extending parallel to said horizontal plane.

Claim 12

An electrical device according to claim 6 wherein said emerging, intermediate and end portions of each of said leads comprise an integral lead formed from flat sheet stock.

Claim 13

An electrical device according to claim 10 wherein said main body has a generally rectangular shape with major and minor axes parallel to said horizontal plane and a thickness dimension perpendicular to said horizontal plane.

Claim 14

An electrical device according to claim 11 wherein at least one of said leads has its emerging portion adjacent a corner of said main body.

Claim 15

An electrical device according to claim 10 wherein said main body has a generally cylindrical shape with a radial dimension parallel to said horizontal plane and a thickness dimension perpendicular to said horizontal plane.

Claim 16

An electrical device according to claim 6 wherein said main body comprises an electrical device housing having insulating sidewalls perpendicular to said horizontal plane and surrounding said central geometric point and said leads extend generally inward from said sidewalls.

Claim 17

An electrical device according to claim 6 wherein said main body is a molded plastic body.

Claim 18

An electrical device (component/housing) having an improved lead frame, comprising: an electrical device comprising a main body having a generally rectangular parallelepiped configuration, an associated horizontal plane and having a geometric central point in the plane, and insulating wall portions; and a lead frame bonded to said insulating wall portions of said body and comprising at least one electrical lead positioned adjacent each one of four different corners of said body about said central point, each of said leads formed of flat sheet stock having a predetermined thickness, each of said leads having an emerging portion extending from said insulating wall portions of said body and connected by an intermediate flexible planar portion to an end lead portion to be bonded to another structure, said intermediate portion having orthogonal length and width dimensions and a thickness corresponding to said sheet stock thickness, said width dimension being measured parallel to said horizontal plane, said intermediate portion extending along its length dimension between said emerging and end lead portions in a direction inclined with respect to said horizontal plane, wherein the improvement comprises each of said intermediate lead portions being oriented such that for a vertical projection of said lead onto said horizontal plane, said width dimension of said intermediate portion is substantially perpendicular to a radial line in said horizontal plane drawn from said geometric central point toward the projection, in said horizontal plane, of said end lead portion connected to said intermediate portion, whereby after the leads are bonded to another structure, thermal expansion stresses which may act on the leads and/or the bonds of these leads to the other structure are minimized due to the orientation of the intermediate lead portions.

Claim 19

An electrical device (component/housing) having an improved lead frame, comprising: an electrical device comprising a main body having a generally rectangular parallelepiped configuration, an associated horizontal plane and having a geometric central point in the plane, and insulating wall portions; and a lead frame bonded to said insulating wall portions of said body and comprising at least one electrical lead positioned adjacent each one of four different corners of said body about said central point, each of said leads formed of flat sheet stock having a predetermined thickness, each of said leads having an emerging portion extending from said insulating wall portions of said body and connected by an intermediate flexible planar portion to an end lead portion to be bonded to another structure, said intermediate portion having orthogonal length and width dimensions and a thickness corresponding to said sheet stock thickness, said width dimension being measured parallel to said horizontal plane, said intermediate portion extending along its length dimension between said emerging and end lead portions in a direction inclined with respect to said horizontal plane, wherein the improvement comprises each of said intermediate lead portions being oriented such that for a vertical projection of said lead onto said horizontal plane, said width dimension of said intermediate portion is substantially perpendicular to a radial line in said horizontal plane drawn from said geometric central point toward the projection, in said horizontal plane, of said end lead portion connected to said intermediate portion, whereby after the leads are bonded to another structure, thermal expansion stresses which may act on the leads and/or the bonds of these leads to the other structure are minimized due to the orientation of the intermediate lead portions.

Claim 20

An electrical device according to claim 16 wherein said emerging, intermediate and end portions of each of said leads comprise an integral lead formed from flat sheet stock.

Claim 21

An electrical device according to claim 17 wherein each of said emerging portions comprises a planar portion extending from said insulating wall portions of said body, parallel to said horizontal plane, to said intermediately portion.

Claim 22

An electrical device according to claim 18 wherein each of said intermediate portions extend substantially perpendicular with respect to said horizontal plane.

Claim 23

An electrical device according to claim 19 wherein each of said end portions of said leads includes a planar portion extending parallel to said horizontal plane.

Claim 24

A thermally stable connection arrangement comprising: a substrate having an electrical conductor thereon, the substrate having a first predetermined coefficient of thermal expansion; a base upon which the substrate is located at a first position, the base having a second predetermined coefficient of thermal expansion; and a housing fixed to the base at a second position, the housing having at least one lead extending therefrom to the electrical conductor to which it is connected at a third position, and the lead having a third predetermined coefficient of thermal expansion, a first distance between the first position and the third position and a second distance between the first position and the second position being in a ratio substantially equal to the ratio of the difference between the second and third predetermined coefficients of thermal expansion and the difference between the first and third predetermined coefficients of thermal expansion, whereby there is substantially no differential movement due to thermal expansion between the substrate and the lead at the third position.

Claim 25

A thermally stable connection arrangement comprising: a substrate having an electrical conductor thereon, the substrate having a first predetermined coefficient of thermal expansion; a base upon which the substrate is located at a first position, the base having a second predetermined coefficient of thermal expansion; and a housing fixed to the base at a second position, the housing having at least one lead extending therefrom to the electrical conductor to which it is connected at a third position, and the lead having a third predetermined coefficient of thermal expansion, a first distance between the first position and the third position and a second distance between the first position and the second position being in a ratio substantially equal to the ratio of the difference between the second and third predetermined coefficients of thermal expansion and the difference between the first and third predetermined coefficients of thermal expansion, whereby there is substantially no differential movement due to thermal expansion between the substrate and the lead at the third position.

Claim 26

A thermally stable connection arrangement according to claim 21 comprising a plurality of leads arranged radially with respect to the center of the housing.

Claim 27

A thermally stable connection arrangement according to claim 21 comprising a plurality of leads interdigitated and extending across the housing from remote sides thereof to the electrical conductor.

Claim 28

A thermally stable connection arrangement according to claim 21 wherein the base comprises a heat sink.

Claim 29

A thermally stable connection arrangement according to claim 21 wherein the substrate comprises a heat conducting ceramic.

Claim 30

A thermally stable connection arrangement according to claim 21 wherein the ceramic comprises aluminum oxide.

Claim 31

A thermally stable connection arrangement according to claim 21 wherein the connection between the lead and the electrical conductor on the substrate is soldered.

Claim 32

A thermally stable connection arrangement according to claim 21 wherein the lead extends through the housing.

Claim 33

A thermally stable connection arrangement according to claim 21 wherein the housing comprises a plastic molding.

Claim 34

A thermally stable connection arrangement according to claim 29 wherein the lead is embedded in the housing.