Methods of forming a microshield on standard QFN package

Patent metadata

Field	Value
Publication number	US-9627230-B2
Application number	US-201113036272-A
Country	US
Kind code	B2
Filing date	Feb 28, 2011
Priority date	Feb 28, 2011
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

Shielded electronic packages may have metallic lead frames to connect an electromagnetic shield to ground. In one embodiment, a metallic lead frame of the electronic package and a surface of the metallic lead frame defines a component area for attaching an electronic component. The metallic lead frame includes a metallic structure associated with the component area that may have a grounding element for connecting to ground and one or more signal connection elements, such as signal leads, for transmitting input and output signals. The electromagnetic shield connects to the metallic lead frame to safely connect to ground while maintaining the signal connection elements isolated from the shield.

First claim

What is claimed is:

1. A method of manufacturing an electronic package, comprising:
providing a metallic lead frame having a component area on a surface of the metallic lead frame and a metallic structure associated with the component area, wherein the metallic structure comprises a plurality of connection portions, each connection portion comprising a plurality of connection leads;
providing an electronic component on the component area;
providing an overmold within and over the metallic lead frame such that the overmold covers the component area;
forming an opening through the overmold that exposes at least a section of the metallic structure;
applying an electromagnetic shield material within the opening and over the overmold to form an electromagnetic shield over the component area such that the electromagnetic shield is coupled to at least the section of the metallic structure exposed by the opening;
coupling the metallic structure to ground with a grounding portion;
partially etching the grounding portion through a first etch; and
partially etching the metallic lead frame on a subset of the plurality of connection leads such that remaining ones of the plurality of connection leads other than the subset form grounding leads different from the grounding portion for connection to ground with a second etch.

2. The method of claim 1 , further comprising:
wherein forming the opening through the overmold that exposes at least the section of the metallic structure includes exposing at least a section of the grounding portion; and
wherein applying the electromagnetic shield material within the opening and over the overmold to form the electromagnetic shield over the component area includes forming the electromagnetic shield such that the electromagnetic shield is coupled to at least the section of the grounding portion.

3. The method of claim 1 , wherein:
forming the opening through the overmold that exposes at least the section of the metallic structure comprises forming the opening such that the section of the metallic structure exposed by the opening includes at least a section of the grounding portion; and
applying the electromagnetic shield material within the opening and over the overmold to form the electromagnetic shield over the component area such that the electromagnetic shield is coupled to at least the section of the metallic structure exposed by the opening includes forming the electromagnetic shield such that the electromagnetic shield is coupled to at least the section of the grounding portion exposed by the opening.

4. The method of claim 1 , wherein the metallic structure includes a signal connection element for transmitting signals.

5. The method of claim 1 , further comprising applying a noble metal to at least a section of the metallic lead frame.

6. The method of claim 1 , wherein the metallic lead frame has a component portion that includes the component area on the surface of the metallic lead frame and the metallic structure associated with the component area extends along a periphery of the component portion.

7. The method of claim 6 , wherein the metallic structure substantially surrounds the periphery of the component portion.

8. The method of claim 6 , wherein providing the metallic lead frame having the component area on the surface of the metallic lead frame and the metallic structure associated with the component area comprises:
providing the metallic lead frame so as to include a first side and a second side oppositely disposed from the first side, the first side having the component area on the surface of the metallic lead frame; and
wherein the first etch comprises performing a first partial etch on the grounding portion from the second side of the metallic lead frame.

9. The method of claim 8 , wherein providing the metallic lead frame having the component area on the surface of the metallic lead frame and the metallic structure associated with the component area comprises:
providing the metallic lead frame such that the metallic structure further includes a signal lead for transmitting signals; and
wherein the second etch comprises performing a second partial etch on at least a section of the signal lead from the first side of the metallic lead frame such that at least the section of the signal lead is partially etched from the first side of the metallic lead frame.

10. The method of claim 6 wherein the metallic structure substantially surrounds the periphery of the component portion and each of the plurality of connection portions is positioned between one of a plurality of grounding portions and another one of the plurality of grounding portions.

11. A method of manufacturing a plurality of electronic packages, comprising:
providing a metallic lead frame having a plurality of component portions and a plurality of metallic structures wherein each of the plurality of metallic structures extends about a periphery of one of the plurality of component portions and each of the plurality of component portions defines a component area on a surface of the metallic lead frame;
providing electronic components on component areas;
providing an overmold within the metallic lead frame and over the surface of the metallic lead frame to cover the component areas;
forming channels through the overmold about the periphery of each of the plurality of component portions, wherein the channels expose at least a section of each of the plurality of metallic structures; and
applying an electromagnetic shield material over the overmold and in the channels to form electromagnetic shields wherein each electromagnetic shield is formed over the component area of one of the plurality of component portions and at least the section of each of the plurality of metallic structures is coupled to one of the electromagnetic shields.

12. The method of claim 11 , wherein each of the plurality of metallic structures substantially surrounds one of the plurality of component portions.

13. The method of claim 11 , wherein providing the metallic lead frame having the plurality of component portions and the plurality of metallic structures comprises:
providing the metallic lead frame so that the metallic lead frame includes a first side and a second side oppositely disposed from the first side, the first side having the component areas, each of the plurality of metallic structures having a grounding portion that is coupled to the metallic lead frame for connecting to ground; and
performing a first partial etch on the grounding portion of each of the plurality of metallic structures from the second side of the metallic lead frame such that the grounding portion of each of the plurality of metallic structures is partially etched on the second side of the metallic lead frame.

14. The method of claim 13 , wherein providing the metallic lead frame having the plurality of component portions and the plurality of metallic structures further comprises:
providing the metallic lead frame such that each of the plurality of metallic structures includes a signal lead for transmitting signals; and
performing a second partial etch on at least a section of the signal lead of each of the plurality of metallic structures from the first side of the metallic lead frame such that at least the section of the signal lead of each of the plurality of metallic structures is partially etched on the first side of the metallic lead frame.

15. The method of claim 14 , further comprising:
wherein forming the channels through the overmold that exposes at least the section of each of the plurality of metallic structures comprises fo

Assignees

• Carey Dan
• Calhoun Brian Howard
• Qorvo Us Inc

Inventors

• Carey Dan
• Calhoun Brian Howard

Classifications

• H10W42/276

  the arrangements being on an external surface of the package, e.g. on the outer surface of an encapsulation · CPC title

• H10W74/00

  Encapsulations, e.g. protective coatings · CPC title

• H10W74/127

  characterised by arrangements for sealing or adhesion · CPC title

• H10W72/0198

  batch processes · CPC title

• H10W90/756

  between a chip and a stacked lead frame, conducting package substrate or heat sink · CPC title