JP2002343904A - Semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device which is easy to handle, even if being formed thin, while semiconductor elements are formed thin to mount them at high density in the prior art, but base materials used for the semiconductor elements are brittle enough to break, thus making difficult handling in the thinned condition. SOLUTION: A semiconductor element 1 is mounted in a face-down manner on a surface of a printed board 5 with electrode posts 3 formed thereon, the electrode posts 3 and the element 1 are molded with a resin 4, and only the molded surface of the resin 4 is polished until the posts 3 appear on the surface. Thus, the semiconductor element is mounted by face-down mounting less in increase in the thickness on a flexible printed board and the polishing follows to realize a semiconductor device easy to handle, even if being formed thin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device in which semiconductor elements are mounted at high density.

[0002]

2. Description of the Related Art In recent years, with the rapid spread of small portable devices, demand for semiconductor devices has been rapidly growing. In particular,
Despite the lightness, size, and size of devices, multifunctionality is demanded, so that a large number of semiconductor elements must be mounted at high density. For this reason, semiconductor devices have been handled as packaged products so far, but recently, they are not rarely handled as bare chips, and furthermore, three-dimensional mounting in which semiconductor devices are stacked in the thickness direction has been proposed. . Current,
The main three-dimensional implementation proposed is shown in FIG. As shown in FIG. 9, unlike the conventional high-density mounting, the three-dimensional mounting can secure a mounting area also in the thickness direction of the printed circuit board, and thus can contribute to further downsizing of the device. Also,
As shown in FIG. 9, in order that lamination in the thickness direction does not lead to expansion of the device in the thickness direction, the semiconductor element is greatly thinned by polishing to solve the problem.

[0003]

However, the base material used for semiconductor elements such as silicon is brittle and easily broken, so that it is very difficult to handle the base material in a thinned state.

Accordingly, the present invention provides a semiconductor device which is easy to handle even if it is made thinner and is suitable for high-density mounting.

[0005]

In order to solve this problem, a semiconductor device according to the present invention comprises a semiconductor element mounted face down on a surface of a printed circuit board on which an electrode post is formed on the electrode post forming surface side. After the electrode posts and the semiconductor element are resin-molded, only the resin mold surface is polished at least until the electrode posts are surfaced. According to the present invention, a semiconductor device is mounted on a flexible printed board using face-down mounting with a relatively small increase in thickness, and then polished. Can be realized.

[0006]

According to the first aspect of the present invention, a semiconductor element is mounted face-down on the electrode post forming surface side of a printed circuit board on which an electrode post is formed, and the electrode post and the electrode post are mounted. After the semiconductor element is resin-molded, only the resin-molded surface is polished until at least the electrode posts are surfaced, so that a semiconductor device which is easy to handle even when thinned can be realized.

According to a second aspect of the present invention, there is provided the semiconductor device according to the first aspect, wherein a printed circuit board on which connection electrodes are formed on a back surface side of a place where an electrode post is formed is used. Thus, the semiconductor device according to claim 1 can be stacked in the thickness direction.

A third aspect of the present invention is characterized in that a plurality of the semiconductor devices according to the second aspect are stacked and hot-pressed to connect the electrode posts and the connection electrodes. And a method for stacking the semiconductor device according to claim 2 in the thickness direction.

According to a fourth aspect of the present invention, an electrode post and a connection electrode are connected by soldering between a plurality of the semiconductor devices according to the second aspect. Another method for loading semiconductor devices in the thickness direction is shown.

According to a fifth aspect of the present invention, in a wafer state, an electrode post is formed on an input / output terminal portion of a semiconductor element, a resin is formed around the electrode post, and the wafer is polished on both sides. After thinning at least until the electrode posts are surfaced, the semiconductor elements are singulated, and the diced semiconductor elements are hot-pressed on a printed circuit board to connect the electrode posts and the connection electrodes of the printed circuit board. The connection is characterized in that the electrode posts and the sealing resin layer for connecting to the printed circuit board can be formed in a wafer state, and furthermore, a structure which is easy to handle even when thinned can be realized.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
2 will be described.

(Embodiment 1) FIG. 1 shows Embodiment 1 of the present invention.
FIG. 4 is a schematic view showing a method for forming a semiconductor device in FIG. In FIG. 1, reference numeral 1 denotes a semiconductor element, 2 denotes a bump, 3 denotes an electrode post, 4 denotes a resin, and 5 denotes a printed board.

As shown in FIG. 1, the semiconductor device according to the present embodiment is formed by (a) mounting the semiconductor element 1 face down on a printed board 5 having an electrode post 3 formed on a mounting surface side, and (b) This is performed by molding with a resin 4 so as to cover the semiconductor element 1 and the electrode posts 3 and (c) polishing the surface of the resin 4 at least until the electrode posts 3 are surfaced. The electrode posts are formed by plating copper or solder. For face-down mounting, a method using a thermosetting resin 11 (FIG. 2), a method using a solder bump 2a (FIG. 3), or a method using a gold bump 2b and a conductive paste 12 (FIG. 4).
And so on. In the case of mounting with thermosetting resin, it is necessary to newly mold with resin after face-down mounting, but in the case of mounting with solder bumps or gold bumps and conductive paste, it is used for sealing between the semiconductor element and the printed board Resin is also used to mold the semiconductor element and the electrode posts.

Heretofore, a substrate used for a semiconductor element such as silicon has been fragile and easily broken. On the other hand, in the present embodiment, since the semiconductor element is mounted face-down on a flexible printed board and then polished, the thickness can be reduced to about 10 μm, and the thickness in face-down mounting is increased to 30 μm. Even if the total thickness of the substrate is about 80 μm, a semiconductor device having a thickness of 150 μm or less can be realized with a structure that is easy to handle even if the thickness is reduced.

(Embodiment 2) FIG. 5 shows Embodiment 2 of the present invention.
FIG. 4 is a cross-sectional view of the semiconductor device at FIG. In FIG. 5, 5a indicates a printed circuit board, and 6 indicates a connection electrode.

As shown in FIG. 5, the semiconductor device according to the present embodiment has substantially the same form as that of the first embodiment.

A feature is that a printed circuit board 5a having connection electrodes 6 formed on the back surface side of the places where the electrode posts 3 are formed is used. With this configuration, stacking in the thickness direction for realizing higher-density mounting can be performed.

FIGS. 6 and 7 show two methods of stacking in the thickness direction. First, in one method, as shown in FIG. 6, a plurality of semiconductor devices 7 described in the present embodiment are stacked and hot-pressed to connect the electrode posts 3 and the connection electrodes 6. At the time of hot pressing, the resin 4 is adhered to the printed circuit board 5a, and has a structure with sufficient connection reliability. Next, as shown in FIG. 7, another method is to connect the electrode posts 3 and the connection electrodes 6 with the solder 8 between the semiconductor devices 7 shown in this embodiment.

(Embodiment 3) FIG. 8 shows Embodiment 3 of the present invention.
FIG. 4 is a schematic view showing a method for forming a semiconductor device in FIG. In FIG. 8, 3a denotes an electrode post, 4a denotes a resin, 5c denotes a printed board, 9 denotes a wafer, 10 denotes an input / output terminal, 13 denotes a pressure heating tool, and 14 denotes a dicing saw.

As shown in FIG. 8, the semiconductor device according to the present embodiment includes (a) an electrode post 3a formed on an input / output terminal 10 of a semiconductor element 1 in a state of a wafer 9, and (b) an electrode post 3a. (C) After the wafer 9 is thinned by double-side polishing until at least the electrode posts 3a are surfaced, (d) the wafer 9 is separated into individual semiconductor elements 1,
(E) The individualized semiconductor elements 1 are formed by hot pressing on the printed circuit board 5c. At the time of hot pressing, the resin is adhered to the printed circuit board to form a structure capable of obtaining sufficient connection reliability. The electrode posts are formed by plating copper or solder.

As described above, in the present embodiment, the formation of the electrode posts for connecting to the printed circuit board and the sealing resin layer can be performed in a wafer state in which a large number of electrode posts can be collectively processed. Since the polishing is performed in a state in which it is made thin, it is possible to realize a structure that is easy to handle even if the thickness is reduced.

[0022]

As described above, the semiconductor device according to the present invention is:
Since the semiconductor element is mounted on a flexible printed circuit board using face-down mounting with a relatively small increase in thickness, and then polished, it is possible to realize a form that is easy to handle even if the thickness is reduced.

[Brief description of the drawings]

FIG. 1 is a schematic process cross-sectional view illustrating a method for forming a semiconductor device in Embodiment 1.

FIG. 2 is a schematic process sectional view showing a mounting method using a thermosetting resin.

FIG. 3 is a schematic process sectional view showing a mounting method using solder bumps.

FIG. 4 is a schematic process sectional view showing a mounting method using a gold bump and a conductive paste.

FIG. 5 is a schematic cross-sectional view of a semiconductor device in Embodiment 2.

FIG. 6 is a schematic process cross-sectional view illustrating a method of mounting the semiconductor device according to the second embodiment by hot pressing;

FIG. 7 is a schematic cross-sectional view showing a method for mounting the semiconductor device according to the second embodiment by soldering;

FIG. 8 is a schematic process diagram illustrating a method for forming a semiconductor device in Embodiment 3.

FIG. 9 is a schematic cross-sectional view showing a form in a conventional three-dimensional mounting.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor element 2 Bump 3 Electrode post 4 Resin 5 Printed circuit board

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 25/11 25/18 (72) Inventor Masaaki Katsumata 1006 Kadoma, Oji, Kadoma, Osaka Matsushita Electric Industrial Co., Ltd. Inside

Claims (5)

[Claims] 1. A semiconductor device is mounted face-down on a side of the electrode post forming surface of a printed circuit board on which an electrode post is formed, and the electrode post and the semiconductor element are resin-molded. A semiconductor device which is polished until at least the electrode posts are surfaced. 2. The semiconductor device according to claim 1, wherein a printed circuit board on which connection electrodes are formed on the rear surface side of the place where the electrode posts are formed is used. 3. A semiconductor device comprising a plurality of the semiconductor devices according to claim 2 mounted thereon and hot-pressed to connect the electrode posts and the connection electrodes. 4. A semiconductor device comprising a plurality of semiconductor devices according to claim 2, wherein electrode posts and connection electrodes are connected by soldering. 5. In a wafer state, an electrode post is formed at an input / output terminal portion of a semiconductor element, a resin is formed around the electrode post, and the wafer is thinned by double-side polishing until at least the electrode post is surfaced. After that, the semiconductor element is singulated, and the diced semiconductor element is hot-pressed on a printed circuit board, thereby connecting the electrode posts and connection electrodes of the printed circuit board. apparatus.