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Method for Improving DoP and Warpage in FOWLCSP

IP.com Disclosure Number: IPCOM000250316D
Publication Date: 2017-Jun-28
Document File: 4 page(s) / 461K

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.

Method for Improving DoP and Warpage in FOWLCSP

Background

Spin coated dielectric insulation layer is known to have low coverage or Degree of

Planaration (DoP) over isolated and loose Redistribution Layer (RDL). In multi-metal layers

structure, this disadvantage may cause significant leakage or even electrical short between

two metal layers of the RDL. Meanwhile, isolated and loose RDL tends to have obvious

variation in the thickness when it is formed by the methods of electroplating or

electrochemical deposition.

In Fig. 1, dummy metal patterns are traditionally added to minimize the problems mentioned

above. However, it would cause greater warpage of Fan-Out Wafer Level Chip Scale

Package (FOWLCSP) substrate by adding dummy metal patterns, and therefore will lead to

more difficulties in handling and a greater yield loss.

Fig. 1 The dummy metal patterns are added into Redistribution Layer (RDL)

Description

In the subject of the invention, instead of using solid pads, split open structures are used in

the special dummy metal patterns to provide local planarization to improve DoP, and also to

minimize the associated Copper coverage increment to reduce the impact on warpage.

The first embodiment of the special dummy metal pattern with split open structures is shown

in Fig. 2. The dimensions of the dummy metal pattern and the open structure are also shown

in Fig. 2.

The second embodiment of the special dummy metal pattern with split open structures is

shown in Fig. 3. The dimensions of the dummy metal pattern and the open structure are also

shown in Fig. 3.

Other embodiments of the special dummy metal patterns with split open structures are

proposed in Fig. 4 and Fig. 5.

For all of the embodiments, the split open structures are present only on the sides of the 2-

side or 1-side isolated bottom metal layer of the RDL and presen...