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Substrate manufacturing method with a convex surface using one-step plating

IP.com Disclosure Number: IPCOM000248385D
Publication Date: 2016-Nov-23
Document File: 3 page(s) / 166K

Publishing Venue

The IP.com Prior Art Database

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Page 01 of 3

Substrate manufacturing method with a convex surface using one-step plating

Background

Semiconductor devices are widely used in modern electronic products, in which the substrate of low cost and high quality is a major concern in the current technology. One of the critical problems is the non-wetting contact between the bump material and the bump pad. Shown in Fig. 1, a metal layer is fabricated on the embedded bump pad to increase the wetting bump, and an additional base copper layer is also created to increase the adhesive strength between the metal layer and the bump pad in the conventional method. For example, in the patent US20080003803 A1, a layer of solder wettable material is formed on the exposed surface of the bump pad and the sidewalls and substantially on the comers of the solder mask layer.

Fig. 1 An additional base copper layer in the conventional method

However, the conventional method of complex steps to form the bump on the bump pad has a high risk for registration and adhesion, especially when a convex surface is present.

Description

This invention discloses a substrate with a convex surface and the manufacturing method thereof using a one-step plating process to form a single metal layer. The subject invention has the advantages of making the metal layer more easily and rendering stronger adhesion between the metal layer and the bump pad so that there is no risk for registration and delamination, which will be described in detail later.

In Fig. 2, the substrate with a convex surface is shown for the subject invention. Compared with the conventional substrate in Fig. 1, an additional base copper is eliminated between the single metal layer and the bump pad.

Fig. 2 The substrate with a convex surface for the subject invention


Page 02 of 3

Substrate manufacturing method with a convex surface using one-step plating

The manufacturing processes of the substrate with a convex surface for the subject invention are shown from Fig. 3 to Fig 5. In Fig. 3, first, a carrier is prepared of a detach core in the center and first copper layers on both the top and bottom sides. The subject invention adopts
a dual manufacture strategy in which the same processes are conducted on both the top and bottom sides of the carrier before the detach core is removed; and thus the identical structures formed on the top side and the bottom side are mirrored to the detach core. Therefore, the processes below are described on the top side only. Second, a polyimide (PI) layer is formed on the first copper layer and completely covers the top surface. Third, first vias are formed by a PI etching process or a laser process; and then a first copper plating is formed in an electroless copper plating process on the top surface and sidewalls of the PI layer, with a portion of the first copper layer exposed through the first vias. Fourth, first copper vias are formed by filling the first vias wi...