JPH04304645A - Method for mounting semiconductor element - Google Patents

Abstract

PURPOSE:To eliminate an improper electric connection due to removal of conductive fillers between an electrode of a semiconductor element (IC chip) and an electrode of a circuit board in a method for mounting the element through the filler on the board. CONSTITUTION:A transparent insulating film 12 is formed in a position except an electrode of a recess 13 shape on a circuit board 10, conductive fillers 14 are but in the recess 13, an ultraviolet-ray curing adhesive 15 is put in the recess 13 which is filled with the fillers 14, and a semiconductor element 15 is mounted on the board 10 through the fillers 14.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of mounting a semiconductor element (IC) on a circuit board.

0002

[Prior Art] Conventionally, technologies in this field include:
For example, there was one described in Japanese Patent Application Laid-Open No. 62-244142. FIG. 4 is a cross-sectional view of such a conventional semiconductor device. As shown in this figure, 1 is a glass substrate on which an ITO electrode 2 is formed for electrical connection with the IC chip, 3 is an adhesive for fixing the IC chip and the glass substrate 1, and 4 is an adhesive. It is a conductive filler contained in the adhesive that contributes to the electrical connection between the IC chip and the ITO electrode 2. Here, the adhesive 3 and the conductive filler 4 constitute the anisotropic conductive adhesive 5. There is. 6 is an IC chip, 7 is an Al electrode formed on the IC chip 6, 8 is an Au bump formed on the Al electrode, 9 is for protecting the circuit wiring on the IC chip from humidity, etc.; This is an insulating layer to prevent electrical contact with the outside.

FIG. 3 shows the mounting process of the semiconductor element as described above.
This will be explained with reference to. First, as shown in FIG. 3(a), an anisotropic conductive adhesive 5 is formed on a circuit board 1 made of a glass substrate. Normally, this step involves an anisotropic conductive adhesive 5 containing a conductive filler 4 dispersed in a predetermined amount in advance.
is temporarily adhered onto the circuit board 1. Next, as shown in FIG. 3(b), the IC chip 6 on which the Au bumps 8 are formed is aligned onto the circuit board 1.

Next, as shown in FIG. 3(c), the IC chip 6 is heat-pressed using a tool to complete the process.

[0005]

[Problems to be Solved by the Invention] However, in the above-mentioned conventional semiconductor element mounting process, when connecting the electrodes of the minute IC chip 6, whether or not an electrical connection has been made is determined by the presence of the anisotropic conductive adhesive 5. There was a problem that it depended on the amount of conductive filler 4 to be dispersed. The present invention
To provide a method for mounting a semiconductor element which eliminates the above-mentioned problems, eliminates electrical connection defects, and has excellent electrical connection reliability in a semiconductor element mounting method in which electrical connection is made through a conductive filler. With the goal.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a method for mounting a semiconductor element onto a circuit board via a conductive filler, in which an electrode portion other than a concave-shaped electrode portion is formed on the circuit board. a step of forming an insulating film on the part;
The method includes a step of placing a conductive filler in the recess, a step of putting an adhesive into the recess containing the conductive filler, and a step of mounting the semiconductor element on the circuit board via the conductive filler. It is something.

[0007] Furthermore, a method for mounting a semiconductor element on a circuit board via a conductive filler includes a step of forming a recess in an electrode portion on the circuit board, and a step of inserting a conductive filler into the formed recess. , a step of putting an adhesive into the recess, and a step of mounting a semiconductor element on the circuit board via the conductive filler.

[0008]

[Operation] According to the present invention, the electrode part is formed into a recessed part, a conductive filler and an adhesive are put in the recessed part, and the semiconductor element is mounted on the circuit board via the conductive filler. Place the filler on the electrode part (transparent electrode) on the circuit board.
It is possible to eliminate electrical connection failures due to deviation of the conductive filler between the electrode portions of the semiconductor element (IC chip) and the electrode portions of the circuit board. Furthermore, short circuits between electrodes can be prevented.

[0009]

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a semiconductor device mounting process showing an embodiment of the present invention. First, as shown in FIG. 1A, on a transparent circuit board 10 on which a transparent electrode 11 is formed, an insulating transparent film 12 such as SiO several thousand Å~
It is formed with a thickness of several μm. Formation method is sputtering, P-C
After forming a film using a device such as VD, a pattern may be formed by photolithography, or a method such as a thick film printing method may be used. Here, the film thickness of the insulating transparent film 12 is assumed to be a.

Next, as shown in FIG. 1B, a conductive filler 14 having a diameter of several thousand Å to several μm is placed in the recess 13 formed by the transparent electrode 11 and the insulating transparent film 12. At this time, the thickness a of the insulating transparent film 12 is smaller than the height b of the conductive filler 14 placed in the recess 13, that is, b>a
must satisfy the following relationship. Next, Figure 1(c)
As shown in FIG. 2, an ultraviolet curing adhesive 15 is placed on the conductive filler 14 in the recess 13 of the transparent electrode 11.

Next, as shown in FIG. 1(d), the IC chip 16 and the circuit board 10 are aligned using a well-known method, and the IC chip electrode 17 is bonded to the ultraviolet curing adhesive 15 and the conductive filler 14. Make sure it's on top. Next, Figure 1(e
), the semiconductor element mounting process is completed by applying pressure and irradiating ultraviolet light from the light source 18 on the circuit board 10 side.

With this configuration, the IC chip electrode 17 and the transparent electrode 11 can be reliably electrically connected through the conductive filler 14 as shown in FIG. The IC chip 16 can be mounted on. Next, other embodiments of the present invention will be described with reference to the drawings. FIG. 5 is a cross-sectional view of a semiconductor device mounting process showing another embodiment of the present invention.

First, as shown in FIG. 5(a), a transparent electrode 21 is formed on a circuit board 20. The electrodes may be formed by a device such as sputtering, vapor deposition, or CVD, and the recesses 22 (including holes) may be formed in the portions of the IC that are in contact with the electrodes by a photolithography process, or may be formed by thick film printing. . The thickness is several thousand Å to several μm. Here, the film thickness of the transparent electrode 21 is assumed to be a.

Next, as shown in FIG. 5(b), a conductive filler 23 having a diameter of several thousand Å to several μm is placed in the recess 22 formed in the transparent electrode 21. At this time, the height b of the conductive filler in the recess 22 must be higher than the film thickness a of the transparent electrode. In other words, the relationship b>a must be satisfied. Next, as shown in FIG. 5(c), an ultraviolet curing adhesive 24 is applied to the transparent electrode 21 and the conductive filler 23.

Next, as shown in FIG. 5(d), the IC chip 25 and the circuit board 20 are aligned using a well-known method, and the IC chip electrode 26 is coated with the ultraviolet curing adhesive 24 and the conductive filler. The mounting process of the semiconductor element is completed by placing the semiconductor element on top of the semiconductor element 23 and applying pressure and irradiating ultraviolet rays from the light source 27 on the circuit board 20 side. With this configuration, as shown in FIG. 6, the IC chip electrode 26 and the transparent electrode 21 are connected via the conductive filler 23.
A reliable electrical connection can be made with the circuit board 20.
The IC chip 25 can be mounted on. In addition,
FIG. 6(a) is a cross-sectional view of the semiconductor element, and FIG. 6(b) is a plan view of the semiconductor element.

Furthermore, in place of the ultraviolet curable adhesive in each of the above-described embodiments, the same effect can be obtained by using, for example, a thermosetting adhesive that hardens when heat is applied. At this time, any method suitable for the adhesive used may be used for curing the adhesive. Furthermore, the circuit board 1 described above
In some cases, the electrodes 11, 21, and the insulating film 12 do not need to be transparent. Further, by making the diameter of the conductive filler finer, it becomes possible to connect fine electrodes.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and various modifications can be made based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

[0018]

As described in detail above, according to the present invention, the following effects can be achieved. The electrode part is shaped like a concave part, a conductive filler and an adhesive are put into the concave part, and the semiconductor element is mounted on the circuit board via the conductive filler. (transparent electrode), and it is possible to eliminate electrical connection failures due to deviation of the conductive filler between the electrode part of the semiconductor element (IC chip) and the electrode part of the circuit board. Furthermore, short circuits between electrodes can be prevented.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a semiconductor device mounting process showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a semiconductor device packaged according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view of a conventional semiconductor device mounting process.

FIG. 4 is a cross-sectional view of a conventional semiconductor device mounted thereon.

FIG. 5 is a cross-sectional view of a semiconductor device mounting process showing another embodiment of the present invention.

FIG. 6 is a diagram showing a mounting state of a semiconductor element showing another embodiment of the present invention.

[Explanation of symbols]

10, 20 Circuit board 11, 21 Transparent electrode 12 Insulating transparent film 13, 22 Recess 14, 23 Conductive filler 15, 24 Ultraviolet curing adhesive 16, 25
IC chip 17, 26 IC chip electrode 18, 27 Light source

Claims (4)

[Claims] 1. A method for mounting a semiconductor element on a circuit board via a conductive filler, comprising the steps of: (a) forming an insulating film on a portion of the circuit board other than the recessed electrode portion; b) putting a conductive filler into the recess, (c) putting an adhesive into the recess containing the conductive filler, and (d) mounting a semiconductor element onto a circuit board via the conductive filler. 1. A method for mounting a semiconductor device, comprising the steps of: 2. The semiconductor device mounting method according to claim 1, wherein the thickness a of the insulating film is lower than the height b of the conductive filler entered into the recess. Method. 3. A method for mounting a semiconductor element on a circuit board via a conductive filler, which includes the steps of (a) forming a recess in an electrode portion on the circuit board; and (b) adding conductive material to the formed recess. A semiconductor device comprising: (c) putting an adhesive into the recess; and (d) mounting a semiconductor element on a circuit board via the conductive filler. How to implement. 4. The method for mounting a semiconductor device according to claim 3, wherein the height a of the electrode portion is lower than the height b of the conductive filler that has entered the recess. .