SHIELDED SEMICONDUCTOR DEVICE AND LEAD FRAME THEREFOR

• US 20200131030A1
• Filed: 10/30/2018
• Published: 04/30/2020
• Est. Priority Date: 10/30/2018
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Inventors: Ngion, Lee Fee, Poh, Zi-Song, Vincent, Michael B.
• Granted Patent: US 10,654,709 B1
• Time in Patent Office: Days
• CPC Class Codes: B81B 2201/0264 Pressure sensors
• CPC Class Codes: B81B 2207/012 the micromechanical device and the control or processing electronics being separate parts in the same package
• CPC Class Codes: B81B 2207/098 Arrangements not provided for in groups B81B2207/092 - B81B2207/097
• CPC Class Codes: B81B 7/0061 suitable for fluid transfer from the MEMS out of the package or vice versa, e.g. transfer of liquid, gas, sound
• CPC Class Codes: B81B 7/0064 for protecting against electromagnetic or electrostatic interferences
• CPC Class Codes: B81B 7/007 Interconnections between the MEMS and external electrical signals
• CPC Class Codes: B81C 1/00301 Connecting electric signal lines from the MEMS device with external electrical signal lines, e.g. through vias
• CPC Class Codes: B81C 1/00309 suitable for fluid transfer from the MEMS out of the package or vice versa, e.g. transfer of liquid, gas, sound
• CPC Class Codes: B81C 2203/0154 Moulding a cap over the MEMS device
• CPC Class Codes: B81C 2203/0792 Forming interconnections between the electronic processing unit and the micromechanical structure
• CPC Class Codes: G01L 9/0042 Constructional details associated with semiconductive diaphragm sensors, e.g. etching, or constructional details of non-semiconductive diaphragms details about the integration or bonding of piezoresistor in or on the diaphragm G01L9/0052 and G01L9/0057 respectively
• CPC Class Codes: H01L 21/561 Batch processing
• CPC Class Codes: H01L 2224/32145 the bodies being stacked
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48145 the bodies being stacked
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/83 using a layer connector
• CPC Class Codes: H01L 2224/85 using a wire connector
• CPC Class Codes: H01L 2224/97 : the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 23/3107 : the device being completely enclosed
• CPC Class Codes: H01L 23/49551 : characterised by bent parts
• CPC Class Codes: H01L 23/49582 : Metallic layers on lead frames
• CPC Class Codes: H01L 23/552 : Protection against radiation, e.g. light or electromagnetic waves
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 : Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding

Abstract

A shielded semiconductor device is assembled using a lead frame having a die receiving area, leads disposed around the die receiving area, and a bendable strip formed in the die receiving area. Each lead has an inner lead end that is spaced from but near to one of the sides of the die receiving area and an outer lead end that is distal to that side of the die receiving area. An IC die is attached to the die receiving area and electrically connected to the inner lead ends of the leads. An encapsulant is formed over the die and the electrical connections and forms a body. The strip is bent to extend vertically to a top side of the body. A lid is formed on the top side of the body and is in contact with a distal end of the vertical strip.

Claims

1. An article of manufacture, comprising:

a lead frame, wherein the lead frame includes a die receiving area, a plurality of leads disposed on at least one side of the die receiving area and that are generally perpendicular to the at least one side of the die receiving area, wherein each lead of the plurality of leads has an inner lead end that is spaced from but near to the at least one side of the die receiving area and an outer lead end that is distal to the at least one side of the die receiving area, and a strip formed in the die receiving area that is bendable to a substantially vertical position for electrical connection to a package lid, and wherein the die receiving area, the plurality of leads, and the strip are all formed of the same electrically conductive sheet material.

2. The article of claim 1, wherein the strip is formed along one side of the die receiving area.

3. The article of claim 1, wherein the strip has a width of 0.05 mm to 0.20 mm, and a length of 0.50 mm to 2.0 mm.

4. The article of claim 1, wherein the lead frame is formed from a copper sheet that is plated with a non-corrosive metal or metal alloy.

5. The article of claim 1, wherein the die receiving area is rectangular.

6. The article of claim 5, wherein the plurality of leads includes leads disposed on each of the sides of the die receiving area.

7. The article of claim 1, further comprising:

a first integrated circuit die attached to the die receiving area and electrically connected to the inner lead ends of the plurality of leads; and

an encapsulant formed over the first die, the electrical connections between the first die and the plurality of inner lead ends, wherein the encapsulant forms a body, and wherein the strip is bent vertically and extends to an upper edge of the body.

8. The article of claim 7, further comprising the package lid formed on the upper edge of the body and in contact with the strip.

9. The article of claim 8, wherein the package lid comprises a metal sputter coated on the top edge of the body.

10. The article of claim 7, wherein the first die is electrically connected to the inner lead ends with bond wires.

11. The article of claim 10, further comprising a second integrated circuit die attached to a top surface of the first die and electrically connected to at least one of the first die and the plurality of leads.

12. The article of claim 11, wherein the first die comprises a microcontroller unit and the second die comprises a pressure sensor, wherein there is a void in the encapsulant above the second die and a hole in the package lid that is in communication with the void such that the second die is exposed to the ambient environment outside of the body by way of the hole and the void.

13. The article of claim 12, wherein the package lid is attached to the upper edge of the body with a conductive adhesive and the vertical strip is in contact with the conductive adhesive.

14. A shielded semiconductor device comprising:

a lead frame including a die receiving area, a plurality of leads disposed on at least one side of the die receiving area and that are generally perpendicular to the at least one side of the die receiving area, wherein each lead of the plurality of leads has an inner lead end that is spaced from but near to the at least one side of the die receiving area and an outer lead end that is distal to the at least one side of the die receiving area, and a strip formed in the die receiving area that is bent to a substantially vertical position, and wherein the die receiving area, the plurality of leads, and the strip are all formed of the same electrically conductive sheet material;

a first integrated circuit die attached to the die receiving area and electrically connected to the inner lead ends of the plurality of leads;

an encapsulant formed over the first die and the electrical connections between the first die and the plurality of inner lead ends, wherein the encapsulant forms a body, and wherein the strip extends vertically to an upper edge of the body; and

a package lid formed on the upper edge of the body and in contact with a distal end of the vertical strip such that the vertical strip is in electrical communication with the package lid.

15. The shielded semiconductor device of claim 14, further comprising a second integrated circuit die attached to a top surface of the first die and electrically connected to at least one of the plurality of leads and the first die, and covered with the encapsulant.

16. A method of assembling a shielded semiconductor device, comprising:

providing a lead frame including a die receiving area, a plurality of leads disposed on at least one side of the die receiving area and that are generally perpendicular to the at least one side of the die receiving area, wherein each lead of the plurality of leads has an inner lead end that is spaced from but near to the at least one side of the die receiving area and an outer lead end that is distal to the at least one side of the die receiving area, and a strip formed in the die receiving area that is bent to a substantially vertical position for electrical connection to a package lid, and wherein the die receiving area, the plurality of leads, and the strip are all formed of the same electrically conductive sheet material;

attaching a first integrated circuit (IC) die to the die receiving area of the lead frame;

electrically connecting the first IC die to the inner lead ends of the plurality of leads;

encapsulating the first IC die, the electrical connections and the lead frame with a molding compound, wherein the molding compound forms a body and wherein the distal ends of the plurality of leads are exposed along at least one lateral side of the body and a distal end of the vertical strip is exposed at a top surface of the body; and

forming a metallic lid on the top surface of the body, wherein the exposed distal end of the vertical strip contacts the package lid such that the vertical strip is in electrical communication with the package lid.

17. The method of claim 16, further comprising:

attaching a second IC die to an upper surface of the first IC die and electrically connecting the second IC die to at least one of the first IC die and the inner lead ends of the plurality of leads, wherein the second IC die is covered with the molding compound.

18. The method of claim 17, wherein a void is formed over the second IC die and the package lid includes a hole that is in communication with the void such that the second IC die is exposed to the ambient environment by way of the hole and the void.

19. The method of claim 18, wherein the first IC die is a microcontroller unit and the second IC die is a pressure sensor.

20. The method of claim 16, wherein the lid is formed by sputtering.