Browse Prior Art Database

New EMI Shielding with Composite Material

IP.com Disclosure Number: IPCOM000249327D
Publication Date: 2017-Feb-16
Document File: 4 page(s) / 393K

Publishing Venue

The IP.com Prior Art Database

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 54% of the total text.

New EMI Shielding with Composite Material

Background

In the current semiconductor industry, sputtering and other coating methods for the purpose

of electromagnetic interference (EMI) shielding are used in the molding process after loading

package units on a mold carrier. However, the protection method on the package bottom area

for these EMI shielding technologies has several disadvantages, shown in Fig. 1. In Fig. 1(a),

the major issue is metal deposition around solder balls on the package bottom, which is likely

to cause electrical short failure. Other issues include the package side surface discolor shown

in Fig. 1(b), package dropping and abnormal shielding shown in Fig. 1(c), and structure of

fabric shown in Fig. 1(d).

Fig. 1 the issues with the current coating methods of electromagnetic interference (EMI) shielding

Description

The subject invention discloses a new EMI shielding method with composite material in

various molding process after loading package units on a mold carrier. This new method is

designed to replace the current sputtering and other coating methods for EMI shielding. The

advantages of the new method include, but not limited to, lower machine cost, well-known

process, easy thickness control with shielding material, higher adhesion with the first molding

material.

The first embodiment of the subject invention is shown in Fig. 2. The process flow by

sequence includes the following processes: mold carrier preparation, lamination of temporary

bonding tape on the mold carrier, pick and place package units on the mold carrier, resin

system with multi-layer and filler, molding and post-molding curing with conductive

New EMI Shielding with Composite Material

material, debonding of the mold carrier and temporary bonding tape, mounting solder balls

and finally package singulation.

The new EMI shielding method with composite material is adopted in the fourth step of the

above process flow. Two types of the resin system structure are proposed here: the first

structure (left) from top to the bottom contains a SUS or metal layer on the top, a copper or

metal layer, a SUS or metal layer sandwiched in the middle, and a resin layer with copper or

metal fillers on the bottom; while the second structure (right) from top to the bottom contains

a resin layer with copper or metal fillers on the top, a SUS or metal layer, a resin layer with

copper or metal fillers, a copper or metal layer, a resin layer with copper or metal fillers, a

SUS or metal layer sandwiched in the middle, and a resin layer with copper or metal fillers on

the bottom.

The resin can be embedded molding compound (EMC), substrate PPG or other core material,

paste or film material such as epoxy, and etc. In this embodiment, EMC of a sheet shape is

shown with copper or metal fillers inside. EMC of other shapes, such as a granular shape, a

tablet shape or in liquid can also be used in the process. Meanwhile, the type of fillers can be

meta...