CIRCUIT SUBSTRATE WITH STRONG ADHESION

Abstract

The surface of the circuit substrate is a solder mask. The solder mask protects the electrical circuit on the circuit substrate against suffering from the environmental damage. By dividing the area of the circuit substrate into the solder mask area and the adhesive area, a bismaleimide triazine layer is formed on the surface of the circuit substrate to coarsen the adhesive area and so as to enhance the adhesion strength between the chip and the circuit substrate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more fully describe embodiments of the present invention, reference is made to the accompanying drawings. These drawings are not to be considered limitations in the scope of the invention, but are merely illustrative.

FIG. 1 is a top-view schematic diagram of a known layout for adhering a chip onto the circuit substrate.

FIG. 2 is a top-view schematic diagram of a layout of a coarsened area including multiple adhesive areas on the circuit substrate according to one embodiment of this invention.

FIG. 3 is a top-view schematic diagram of a layout including multiple coarsened areas on the substrate according to one embodiment of this invention.

FIG. 4 is a top-view schematic diagram of a layout including various drawings for different relations between the coarsened area and the adhesive areas on the substrate according to one embodiment of this invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 2 is a top-view schematic diagram of a substrate layout according to one embodiment of this invention. The substrate includes a solder mask area 200 and a large coarsened area 220 having multiple adhesive areas 210. The adhesive areas 210 are coarsened at the same time when the large coarsened area 220 is coarsened, and the coarsening method is to form a bismaleimide triazine layer on the substrate.

FIG. 3 is a top-view schematic diagram of a substrate layout according to one embodiment of this invention. The substrate includes a solder mask area 300 and multiple coarsened areas, and each coarsened area includes multiple adhesive areas 310. For being better understood, the coarsened areas coincide with the adhesive areas 310 in the present embodiment. The coarsening method, similar to the aforementioned, is to form a bismaleimide triazine layer over the adhesive area 310 on the substrate.

The object of the coarsened area is to enhance the adhesion strength for pasting a chip onto the substrate. The area of the coarsened area may be smaller than the area of the adhesive area. Besides, a substrate may include multiple coarsened areas and each coarsened area includes multiple adhesive areas. Therefore, the chips must be pasted on the adhesive area with coarsened surface. For example, the embodiment shown in FIG. 4, a coarsened area 420 includes multiple adhesive areas 410, a coarsened area 421 is smaller than an adhesive area 410, and a coarsened area 422 is bigger than an adhesive area 410.

Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that other modifications and variation can be made without departing the spirit and scope of the invention as claimed.

Claims

1. A substrate, comprising: a solder mask area; andat least one coarsened area with a coarsened surface, surrounded by said solder mask area, wherein said coarsened area comprises at least one adhesive area.

2. A substrate according to claim 1, wherein a bismaleimide triazine material makes said coarsened surface.

3. A substrate according to claim 1, wherein the areas of any two of said coarsened areas are the same.

4. A substrate according to claim 1, wherein the areas of any two of said coarsened areas are different.

5. A substrate according to claim 1, wherein the area of said adhesive area is the same as the area of said coarsened area.

6. A substrate according to claim 1, wherein the area of said adhesive area is different from the area of said coarsened area.