Semiconductor package having an isolation wall to reduce electromagnetic coupling
View Patent ↗A system and method for packaging a semiconductor device that includes a wall to reduce electromagnetic coupling is presented. A semiconductor device has a substrate on which a first circuit and a second circuit are formed proximate to each other. An isolation wall of electrically conductive material is located between the first circuit and the second circuit, the isolation wall being configured to reduce inductive coupling between the first and second circuits during an operation of the semiconductor device. Several types of isolation walls are presented.
1. A semiconductor device comprising:
a substrate with a surface;
a first circuit on the substrate and comprising a plurality of electrical components, including a first transistor, and a first wire bond array electrically coupled between the first transistor and a first lead;
a second circuit on the substrate and comprising a plurality of electrical components, including a second transistor, and a second wire bond array electrically coupled between the second transistor and a second lead;
encapsulation material covering the surface of the substrate, the first and second transistors, the first and second wire bond arrays, and portions of the first and second leads; and
an isolation wall formed of electrically conductive material located in the encapsulation material between the first circuit and the second circuit, the isolation wall formed of a rectangular body of material that extends perpendicularly from the surface of the substrate above a height of the first and second wire bond arrays, wherein the body of material also extends parallel to the surface of the substrate at least between the first and second wire bond arrays, the isolation wall being configured to reduce electromagnetic coupling between the first circuit and the second circuit during an operation of at least one of the first circuit and the second circuit, and wherein the isolation wall includes a plurality of holes through which the encapsulation material may flow during a process of making the semiconductor device.
2. The semiconductor device as recited in claim 1 , further comprising a ground potential node, wherein the isolation wall is electrically connected to the ground potential node.
3. The semiconductor device as recited in claim 2 , wherein the isolation wall is electrically connected to the ground potential node by one of solder, brazing material, and adhesive.
4. The semiconductor device as recited in claim 2 , wherein the isolation wall is received within an aperture in the ground potential node.
5. The semiconductor device as recited in claim 1 , wherein the isolation wall comprises a body of electrically conductive material inserted into a slot in the encapsulation material.
6. The semiconductor device as recited in claim 1 , wherein the first electrical circuit is a carrier amplifier of a Doherty amplifier; and the second electrical circuit is a peaking amplifier of the Doherty amplifier.
7. The semiconductor device as recited in claim 1 , wherein the first transistor has a first gate pad and a first drain pad, the second transistor has a second gate pad and a second drain pad, and the body of material also extends parallel to the surface of the substrate at least between the first and second gate pads and between the first and second drain pads.
8. A semiconductor device comprising:
a substrate with a surface;
a first circuit on the substrate and comprising a plurality of electrical components, including a first transistor, and a first wire bond array electrically coupled between the first transistor and a first lead;
a second circuit on the substrate and comprising a plurality of electrical components, including a second transistor, and a second wire bond array electrically coupled between the second transistor and a second lead;
encapsulation material covering the surface of the substrate, the first and second transistors, the first and second wire bond arrays, and portions of the first and second leads; and
an isolation wall formed of electrically conductive material located in the encapsulation material between the first circuit and the second circuit, the isolation wall formed of a rectangular body of material that extends perpendicularly from the surface of the substrate above a height of the first and second wire bond arrays, wherein the body of material also extends parallel to the surface of the substrate at least between the first and second wire bond arrays, the isolation wall being configured to reduce electromagnetic coupling between the first circuit and the second circuit during an operation of at least one of the first circuit and the second circuit, wherein the isolation wall is formed by a section of a lead frame for the semiconductor device, and wherein the lead frame also includes the first lead and the second lead.
9. The semiconductor device as recited in claim 8 , wherein the lead frame is formed by an electrically conductive sheet, and the isolation wall is formed by a section of the lead frame that is transverse to a plane of the electrically conductive sheet.
10. The semiconductor device as recited in claim 8 , wherein the section is connected by a link to a remainder of the lead frame and the link is bent so that the section is transverse to the remainder of the lead frame.
11. A semiconductor device comprising:
a substrate with a surface;
a first circuit on the substrate and comprising a plurality of electrical components, including a first transistor, and a first wire bond array electrically coupled between the first transistor and a first lead;
a second circuit on the substrate and comprising a plurality of electrical components, including a second transistor, and a second wire bond array electrically coupled between the second transistor and a second lead;
encapsulation material covering the surface of the substrate, the first and second transistors, the first and second wire bond arrays, and portions of the first and second leads; and
an isolation wall formed of electrically conductive material located in the encapsulation material between the first circuit and the second circuit, the isolation wall formed of a rectangular body of material that extends perpendicularly from the surface of the substrate above a height of the first and second wire bond arrays, wherein the body of material also extends parallel to the surface of the substrate at least between the first and second wire bond arrays, the isolation wall being configured to reduce electromagnetic coupling between the first circuit and the second circuit during an operation of at least one of the first circuit and the second circuit, wherein the encapsulation material has a top surface and a slot extending into the encapsulation material from the top surface toward the substrate and between the first circuit and the second circuit, and wherein the isolation wall is located in the slot, and wherein the isolation wall comprises electrically conductive material applied to a surface of the slot.
12. A Doherty amplifier comprising:
a substrate with a surface;
a carrier amplifier on the substrate and comprising a plurality of electrical components, including a first transistor, and a first wire bond array electrically coupled between the first transistor and a first lead;
a peaking amplifier on the substrate adjacent to the carrier amplifier and comprising a plurality of electrical components, including a second transistor, and a second wire bond array electrically coupled between the second transistor and a second lead;
encapsulation material covering the surface of the ground plane, the first and second transistors, the first and second wire bond arrays, and portions of the first and second leads; and
an isolation wall formed of electrically conductive material located in the encapsulation material between the carrier amplifier and the peaking amplifier, the isolation wall formed of a rectangular body of material that extends perpendicularly from the surface of the substrate above a height of the first and second wire bond arrays, wherein the body of material also extends parallel to the surface of the substrate at least between the first and second wire bond arrays, the isolation wall being configured to reduce an electromagnetic coupling between the carrier amplifier and the peaking amplifier during an operation of the Doherty amplifier, and wherein the isolation wall includes a plurality of holes through which the encapsulation material may flow during a process of making the semiconductor device.
13. The Doherty amplifier as recited in claim 12 , further comprising a ground potential node, wherein the isolation wall is electrically connected to the node.
14. The Doherty amplifier as recited in claim 13 , wherein the isolation wall is electrically connected to the ground potential node by one of solder, brazing material, and adhesive.
15. The Doherty amplifier as recited in claim 13 , wherein the isolation wall is received within an aperture in the ground potential node.
16. The Doherty amplifier as recited in claim 12 , wherein the isolation wall comprises a body of electrically conductive material inserted into a slot in the encapsulation material.
17. The Doherty amplifier as recited in claim 12
A Doherty amplifier comprising:
a substrate with a surface;
a carrier amplifier on the substrate and comprising a plurality of electrical components, including a first transistor, and a first wire bond array electrically coupled between the first transistor and a first lead;
a peaking amplifier on the substrate adjacent to the carrier amplifier and comprising a plurality of electrical components, including a second transistor, and a second wire bond array electrically coupled between the second transistor and a second lead;
encapsulation material covering the surface of the ground plane, the first and second transistors, the first and second wire bond arrays, and portions of the first and second leads; and
an isolation wall formed of electrically conductive material located in the encapsulation material between the carrier amplifier and the peaking amplifier, the isolation wall formed of a rectangular body of material that extends perpendicularly from the surface of the substrate above a height of the first and second wire bond arrays, wherein the body of material also extends parallel to the surface of the substrate at least between the first and second wire bond arrays, the isolation wall being configured to reduce an electromagnetic coupling between the carrier amplifier and the peaking amplifier during an operation of the Doherty amplifier, wherein the encapsulation material has a top surface and a slot extending into the encapsulation material from the top surface toward the substrate and between the carrier amplifier and the peaking amplifier, and wherein the isolation wall is located in the slot, and wherein the isolation wall comprises electrically conductive material applied to a surface of the slot.
18. A method of fabricating a semiconductor device, the method comprising:
forming a first circuit on a surface of a substrate, wherein the first circuit includes a first transistor and a first wire bond array electrically coupled between the first transistor and a first lead;
forming a second circuit on the surface of the substrate adjacent to the first circuit, wherein the second circuit includes a second transistor and a second wire bond array electrically coupled between the second transistor and a second lead;
covering the surface of the substrate, the first and second transistors, the first and second wire bond arrays, and portions of the first and second leads with encapsulation material; and
locating an isolation wall of electrically conductive material in the encapsulation material between the first circuit and the second circuit, the isolation wall formed of a rectangular body of material that extends perpendicularly from the surface of the substrate above a height of the first and second wire bond arrays, wherein the body of material also extends parallel to the surface of the substrate at least between the first and second wire bond arrays, the isolation wall being configured to reduce electromagnetic coupling between the first circuit and the second circuit during an operation of the semiconductor device, and wherein the isolation wall includes a plurality of holes through which the encapsulation material may flow during a process of making the semiconductor device.
19. The method as recited in claim 18 , wherein locating an isolation wall comprises forming a lead frame from an electrically conductive sheet, wherein a wall section is defined in the electrically conductive sheet; and bending the wall section transverse to the electrically conductive sheet thereby forming the isolation wall.
20. The method as recited in claim 18 , wherein locating an isolation wall comprises forming a slot in the encapsulation material and defining the isolation wall in the slot.
21. A semiconductor device comprising:
a substrate having a surface;
a circuit on the surface of the substrate and comprising a plurality of electrical components, wherein the circuit has a transistor with an input and an output;
encapsulation material covering the surface of the substrate, the transistor, the input, and the output; and
an isolation wall formed of electrically conductive material located in the encapsulation material between the input and the output, the isolation wall formed of a rectangular body of material that extends perpendicularly from the surface of the substrate above a height of the input and the output, the isolation wall being configured to reduce electromagnetic coupling between the input and the output during an operation of the circuit, and wherein the isolation wall includes a plurality of holes through which the encapsulation material may flow during a process of making the semiconductor device.
22. The semiconductor device as recited in claim 21 , further comprising a ground potential node, wherein the isolation wall is electrically connected to the ground potential node.
23. The semiconductor device as recited in claim 22 , wherein the isolation wall is electrically connected to the ground potential node by one of solder, brazing material, and adhesive.
24. The semiconductor device as recited in claim 22 , wherein the isolation wall is received within an aperture in the ground potential node.
25. The semiconductor device as recited in claim 21 , wherein the isolation wall is formed by a section of a lead frame for the semiconductor device.
26. The semiconductor device as recited in claim 25 , wherein the lead frame is formed by an electrically conductive sheet, and the isolation wall is formed by a section of the lead frame that is transverse to a plane of the electrically conductive sheet.
27. The semiconductor device as recited in claim 25 , wherein the section is connected by a link to a remainder of the lead frame and the link is bent so that the section is transverse to the remainder of the lead frame.
28. The semiconductor device as recited in claim 21 , wherein the encapsulation material has a top surface and a slot extending into the encapsulation material from the top surface toward the substrate and between the input and the output, and wherein the isolation wall is located in the slot.
29. The semiconductor device as recited in claim 28 , wherein the isolation wall comprises electrically conductive material applied to a surface of the slot.
30. The semiconductor device as recited in claim 28 , wherein the isolation wall comprises a body of electrically conductive material inserted into the slot.
31. A semiconductor device comprising:
a substrate with a surface;
a first circuit on the substrate and comprising a plurality of electrical components, including a first transistor, and a first wire bond array electrically coupled between the first transistor and a first lead;
a second circuit on the substrate and comprising a plurality of electrical components, including a second transistor, and a second wire bond array electrically coupled between the second transistor and a second lead;
encapsulation material covering the surface of the substrate, the first and second transistors, the first and second wire bond arrays, and portions of the first and second leads, wherein the encapsulation material has a top surface and a slot extending into the encapsulation material from the top surface toward the substrate and between the first circuit and the second circuit, and wherein the isolation wall is located in the slot;
an isolation wall formed of electrically conductive material located in the encapsulation material between the first circuit and the second circuit, the isolation wall formed of a rectangular body of material that extends perpendicularly from the surface of the substrate above a height of the first and second wire bond arrays, wherein the body of material also extends parallel to the surface of the substrate at least between the first and second wire bond arrays, the isolation wall being configured to reduce electromagnetic coupling between the first circuit and the second circuit during an operation of at least one of the first circuit and the second circuit; and
a plurality of wire bonds encapsulated in the encapsulation material and having exposed sections at a bottom of the slot, wherein a bottom edge of the isolation wall makes electrical contact with the exposed sections of the plurality of wire bonds.
32. A semiconductor device comprising:
a substrate with a surface;
a first circuit on the substrate and comprising a plurality of electrical components, including a first transistor, and a first wire bond array electrically coupled between the first transistor and a first lead;
a second circuit on the substrate and comprising a plurality of electrical components, including a second transistor, and a second wire bond array electrically coupled between the second transistor and a second lead;
encapsulation material covering the surface of the substrate, the first and second transistors, the first and second wire bond arrays, and portions of the first and second leads, wherein the encapsulation material has a top surface and a slot extending into the encapsulation material from the top surface toward the substrate and between the first circuit and the second circuit, and wherein the isolation wall is located in the slot;
an isolation wall formed of electrically conductive material located in the encapsulation material between the first circuit and the second circuit, the isolation wall formed of a rectangular body of material that extends perpendicularly from the surface of the substrate above a height of the first and second wire bond arrays, wherein the body of material also extends parallel to the surface of the substrate at least between the first and second wire bond arrays, the isolation wall being configured to reduce electromagnetic coupling between the first circuit and the second circuit during an operation of at least one of the first circuit and the second circuit; and
one or more electrically conductive posts encapsulated in the encapsulation material and having exposed ends at a bottom of the slot, wherein a bottom edge of the isolation wall makes electrical contact with the exposed ends of the one or more electrically conductive posts.
33. A semiconductor device comprising:
a substrate with a surface;
a first circuit on the substrate and comprising a plurality of electrical components, including a first transistor, and a first wire bond array electrically coupled between the first transistor and a first lead;
a second circuit on the substrate and comprising a plurality of electrical components, including a second transistor, and a second wire bond array electrically coupled between the second transistor and a second lead;
encapsulation material covering the surface of the substrate, the first and second transistors, the first and second wire bond arrays, and portions of the first and second leads, wherein the encapsulation material has a top surface and a slot extending into the encapsulation material from the top surface toward the substrate and between the first circuit and the second circuit, and wherein the isolation wall is located in the slot;
an isolation wall formed of electrically conductive material located in the encapsulation material between the first circuit and the second circuit, the isolation wall formed of a rectangular body of material that extends perpendicularly from the surface of the substrate above a height of the first and second wire bond arrays, wherein the body of material also extends parallel to the surface of the substrate at least between the first and second wire bond arrays, the isolation wall being configured to reduce electromagnetic coupling between the first circuit and the second circuit during an operation of at least one of the first circuit and the second circuit; and
a plurality of electrically conductive vias at a bottom of the slot, wherein a bottom edge of the isolation wall makes electrical contact with the plurality of electrically conductive vias.