Integrated circuit package and method of forming the same
View Patent ↗An integrated circuit package includes an electronic sensor protected by a lid structure. The electronic sensor includes a transducer placed on a backside surface of a lead frame assembly. The lid structure is placed over the transducer and is attached to the lead frame assembly on the backside surface. The lid can define an air cavity around the transducer, such that mold compound, gel, or other protective chemical material is not placed in contact with the transducer. The transducer is therefore protected without a chemical protectant, lowering the cost of the integrated circuit package and maintaining the sensitivity and performance of the transducer.
1. An electronic device comprising:
a lead frame assembly including a lead frame, the lead frame assembly having a horizontal plane defined by a first major surface, and a second major surface opposite the first major surface;
an opening between the first major surface and the second major surface;
a transducer attached to the first major surface over the opening;
a lid structure attached to the first major surface to cover the transducer; and
leads of the lead frame, non-horizontal surfaces of the leads extend in a direction away from the first major surface and opposite to the second major surface and in a same direction as non-horizontal surfaces of the transducer and non-horizontal surfaces of the lid structure extend away from the first major surface and the second major surface.
2. The electronic device of claim 1 , wherein the transducer comprises a pressure sensor.
3. The electronic device of claim 2 , wherein the opening provides a pressure vent for the pressure sensor.
4. The electronic device of claim 1 , wherein the lid structure defines a cavity between the transducer and a bottom surface of the lid structure.
5. The electronic device of claim 1 , wherein the lid structure is composed of copper.
6. The electronic device of claim 1 , wherein the lid structure is composed of stainless steel.
7. The electronic device of claim 1 , wherein the lid structure is composed of plastic.
8. The electronic device of claim 1 , wherein the lead frame assembly further comprises:
a plurality of leads of the lead frame; and
a molding compound structure attached to a portion of the lead frame, the molding compound structure located between gaps of the leads to provide an interlock with the leads, and the molding compound structure defines an exposed flag of the lead frame.
9. The electronic device of claim 8 , wherein the molding compound structure has a similar thickness as the lead frame between the first major surface and the second major surface, wherein the molding compound structure and lead frame together form a substantially coplanar flat surface along the first major surface based on the similar thickness between the molding compound structure and the lead frame.
10. The electronic device of claim 1 , wherein the transducer is a piezoresistive transducer (PRT).
11. A method of forming an electronic device, comprising:
providing a lead frame assembly including a lead frame, the lead frame assembly having a horizontal plane defined by a first major surface, and a second major surface opposite the first major surface, the lead frame having an opening between the first major surface and the second major surface, and leads, non-horizontal surfaces of the leads extend in a direction away from the first major surface and opposite to the second major surface and in a same direction as non-horizontal surfaces of a transducer and non-horizontal surfaces of a lid structure extend away from the first major surface and the second major surface;
attaching the transducer to the first major surface over the opening; and
attaching the lid structure to the first major surface to cover the transducer.
12. The method of claim 11 , wherein the transducer comprises a pressure sensor.
13. The method of claim 12 , wherein the opening provides a pressure vent for the pressure sensor.
14. The method of claim 11 , wherein the lid structure defines a cavity between the transducer and a bottom surface of the lid.
15. The method of claim 11 , wherein the lid structure is composed of copper.
16. The method of claim 11 , wherein the lid structure is composed of stainless steel.
17. The method of claim 11 , further comprising applying a mold compound to the lead frame prior to attaching the lid structure.
18. The method of claim 11 , wherein the mold compound and the lead frame form the first a surface so that the first surface is substantially flat.
19. The method claim 11 , wherein the transducer is a piezoresistive transducer (PRT).
20. An electronic device comprising:
a lead frame assembly including a lead frame, the lead frame assembly having a horizontal plane defined by a first major surface, and a second major surface opposite the first major surface, wherein the lead frame assembly includes;
a plurality of leads; and
a molding compound structure attached to a portion of the lead frame, the molding compound structure located between gaps of the leads to provide an interlock with the leads, and the molding compound structure defines an exposed flag of the lead frame, wherein the molding compound structure has a similar thickness as the lead frame, wherein the molding compound structure and lead frame form a substantially coplanar flat surface along the first and second major surfaces based on the similar thickness between the molding compound structure and the lead frame;
an opening between the first major surface and the second major surface;
a transducer attached to the first major surface over the opening; and
a lid structure attached to the first major surface to cover the transducer, wherein non-horizontal surfaces of the leads extend in a direction away from the first major surface and opposite to the second major surface and in a same direction as non-horizontal surfaces of the transducer and non-horizontal surfaces of the lid structure extend away from the first major surface and the second major surface.