Method of manufacturing an electromagnetic interference shielding layer

Patent metadata

Field	Value
Publication number	US-11848276-B2
Application number	US-201917287326-A
Country	US
Kind code	B2
Filing date	Nov 4, 2019
Priority date	Nov 5, 2018
Publication date	Dec 19, 2023
Grant date	Dec 19, 2023

Abstract

A method of manufacturing a semiconductor package which is at least in part covered by an electromagnetic interference shielding layer. The method includes at least these steps: i. providing the semiconductor package and an ink composition having at least a compound comprising at least one metal precursor and at least one organic compound; ii. applying at least a part of the ink composition onto the semiconductor package, wherein a precursor layer is formed; and iii. treating the precursor layer with an irradiation of a peak wavelength in the range from 100 nm to 1 mm. Further disclosed is a semiconductor package comprising an electromagnetic interference shielding layer comprising at least one metal, wherein the semiconductor package is obtainable by the aforementioned method. Still further disclosed are a semiconductor package comprising an electromagnetic interference shielding layer having a specific conductance and thickness, and uses of an ink composition.

First claim

The invention claimed is:

1. A method of manufacturing a semiconductor package, which is at least in part covered by an electromagnetic interference shielding layer, comprising at least these steps:
i. providing the semiconductor package and an ink composition,
wherein the ink composition comprises at least these constituents:
a) a compound comprising at least one metal precursor, and
b) at least one organic compound;

ii. applying at least a part of the ink composition onto the semiconductor package, wherein a precursor layer is formed; and
iii. treating the precursor layer with an irradiation, wherein at least 80% of the irradiation has a wavelength in the range from 100 nm to 1 mm, based on the total irradiation applied during the treating.

2. The method of claim 1 , wherein the application of the ink composition in step ii. is performed by using inkjet technology.

3. The method of claim 1 , wherein the treating is performed by infrared irradiation having a peak wavelength in the range from 1,500 nm to 4,000 nm.

4. The method of claim 1 , wherein the precursor layer is treated with the irradiation for less than 10 minutes.

5. The method of claim 1 , wherein the total radiative flux density of the irradiation is in the range of from 100 to 1,000,000 W/cm 2 .

6. The method of claim 1 , wherein the at least one organic compound is a terpene.

7. The method of claim 1 , wherein the semiconductor package comprises one or more electrical components, of which at least one is a semiconductor element, wherein the electrical components are at least in part molded with a mold.

8. The method of claim 1 , wherein the electromagnetic interference shielding layer has a thickness of 5 μm at most.

9. The method of claim 1 , wherein the at least one metal precursor has a decomposition temperature in the range from 80 to 500° C.

10. The method of claim 1 , wherein the at least one metal precursor has at least one of these features:
at least one metal cation which is selected from the group consisting of silver, copper and gold, or a combination of any two of them, or all three;
at least one anion which is selected from the group consisting of carboxylate, carbamate, formate and nitrate;
or a combination of any two or more of the at least one metal cation and the at least one anion.

11. The method of claim 1 , wherein the amount of metal in the ink composition is in the range from 1 to 60 wt. %, based on the total weight of the composition.

12. The method of claim 1 , wherein an amount of metal particles in the ink composition is less than 1 wt. %, based on the total weight of the ink composition.

13. A semiconductor package comprising an electromagnetic interference shielding layer comprising at least one metal obtained by the method according to claim 1 , wherein the electromagnetic interference shielding layer adjoins the semiconductor package and has at least one of these features:
a thickness in the range from 5 nm to 5 μm;
a variation of the thickness of less than 50%;
an electrical conductance of at least 5% with respect to the conductance of the bulk metal; and
a printing resolution in the range from 30 to 150 μm;
or a combination of at least two of the features.

14. A semiconductor package comprising at least one electronic component, a mold and a first layer of an electromagnetic interference shielding material, wherein:
the mold surrounds at least a part of the at least one electronic component;
the first layer of the electromagnetic interference shielding material adjoins at least a part of the mold;
the first layer of the electromagnetic interference shielding material is in direct physical contact with the mold;
the specific conductance of the first layer of the electromagnetic interference shielding material is in the range from 5 to 90% of the bulk metal; and
the thickness of the first layer of the electromagnetic interference shielding material is in the range from 5 nm to 5 μm.

15. The semiconductor package of claim 14 , wherein the first layer is a single layer of electromagnetic interference shielding material.

16. The semiconductor package of claim 14 , wherein the electromagnetic interference shielding material comprises a metal selected from the group consisting of silver, gold and copper or a combination of at least two thereof.

17. An article comprising at least two semiconductor packages according to claim 14 , wherein at least two of the semiconductor packages are stacked.

18. A use of an ink composition comprising at least one metal precursor and at least one organic compound for creating an improved conductive layer on a semiconductor package, wherein:
the conductive layer forms an electromagnetic interference shield which layer adjoins to the surface of the semiconductor package;
the ink composition is applied to the semiconductor package using inkjet technology; and
the conductive layer is formed by treating the ink composition with irradiation of a peak wavelength in the range from 100 nm to 1 mm.

19. The use of an ink composition according to claim 18 , wherein the improvement consists of at least one of these features:
A] a thinner yet effective electromagnetic interference shielding layer;
B] the electromagnetic interference shielding layer is less susceptible to mechanical stress or impact; and
C] a better adhesion of the electromagnetic interference shielding layer to the semiconductor package.

20. An article comprising at least two semiconductor packages obtained by a method according to claim 1 wherein at least two of the semiconductor packages are stacked.

Assignees

• Heraeus Deutschland Gmbh & Co Kg
• Heraeus Electronics Gmbh & Co Kg

Inventors

• Neumann Christian
• Boldt Kai-Ulrich
• Thomas Muriel
• Behl Susanne
• Krämer Peter
• Ulland Holger

Classifications

• H10W74/117

  the substrate having spherical bumps for external connection · CPC title

• H10W74/01

  Manufacture or treatment · CPC title

• H10W42/273

  the arrangements being between laterally adjacent chips, e.g. walls between chips · CPC title

• H10W42/276

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

• H10W74/10

  characterised by their shape or disposition · CPC title