JPH06151502A - Mounting method for flip chip of semiconductor element - Google Patents

Abstract

PURPOSE:To put a bump electrode and a base electrode in continuity by a method wherein uncured resin is formed on a bump electrode part of a semiconductor element, the bump electrode is pressed on the base electrode and the resin is melted by heating and then cooled to be cured. CONSTITUTION:An electrode 1a is formed on a semiconductor element 1 by Al evaporation, a passivation film 3 of Si3N4 is formed on a part other than a place at which connection is made with a base 6 and an Au bump electrode 2 is formed on the electrode 1a by a plating method. Thermoplastic resin of epoxy is heated and applied for coating on the bump electrode 2. The bump electrode 2 is aligned in position with a base electrode 7, pressed thereon and heated so that the two electrodes be put in continuity, and the peripheries thereof are covered with cured resin 5a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flip chip mounting method for semiconductor devices.

[0002]

2. Description of the Related Art FIG. 2 is a sectional view showing steps in a conventional semiconductor chip flip-chip mounting method. First, as shown in FIG. 2A, Pb—Sn based solder bumps 22 are formed on the semiconductor element 21. Further, the substrate electrode 2 is provided on the substrate 23.
4 is formed, and a film (for example, SiO ₂ , Si ₃ N ₄ , Cr, or the like) that does not flow solder is formed as the solder dam 25 in order to prevent the flow of solder, except for the places where the solder bumps 22 are connected. Then, the pre-solder 26 is formed at the connection point.

The semiconductor element 21 is mounted on the substrate 2
Alignment is performed so that 3 becomes a predetermined position. Next, the solder bumps 22 of the semiconductor element 21 are butted against the preliminary solder 26 of the substrate 23, and a temperature higher than the melting point (210 to 230 ° C. in Pb—Sn eutectic) so that they are melted.
The semiconductor element 2 is heated as shown in FIG.
The solder bump 22 on 1 and the preliminary solder 26 on the substrate electrode 24 are fused to complete the connection between the two.

[0004]

As described above, the flip-chip connection has a feature that all electrodes can be connected at once and high-density connection is possible, but since it requires heating. In addition, there is a problem that the substrate material used is limited in heat resistance and it is difficult to directly mount the chip on an LCD display or the like.

The present invention eliminates the above-mentioned problems and provides a flip chip mounting method of a semiconductor device, which has high mass productivity and can be connected to a substrate material having low heat resistance.

[0006]

In order to achieve the above object, the present invention provides a semiconductor element mounting method for flip-chip mounting a semiconductor element on a substrate, wherein a bump electrode portion of the semiconductor element is selectively uncured. After the resin is formed, the semiconductor element is pressed onto the substrate to cure the resin in a state where the bumps are pressed against the substrate electrodes.

[0007]

According to the present invention, the uncured resin is selectively coated on the bump electrode portion of the semiconductor element as described above. After that, the semiconductor element is aligned with a predetermined position of the substrate, a resin that cures at a low temperature or UV is interposed, the semiconductor element is pressed against the substrate, the resin is cured, and the bump electrode and the substrate electrode are connected to each other for conduction. To do.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a sectional view of a semiconductor element mounting process showing an embodiment of the present invention. First, FIG. 1 (a)
As shown in FIG.
a is formed in advance, and S
The passivation film 3 made of i ₃ N ₄ is formed in advance,
The Au bump electrode 2 is formed on the electrode 1a by the plating method. Although the process of FIG. 1A is different from that shown in the drawing, it is manufactured by a conventional technique in a wafer state.

Next, as shown in FIG. 1B, using a glass mask 4 having an opening in the bump electrode 2 portion on the semiconductor element 1 in a wafer state, resin 5 is provided only on the opening portion of the bump electrode 2. Coating. In this embodiment, the epoxy-based thermoplastic resin is heated to about 180 ° C., liquefied, and sprayed from above the glass mask 4. Alternatively, although not shown, it is also possible to apply by screen printing to a thickness approximately equal to the height of the bump electrodes 2 and cure. That is, the applied thermoplastic resin returns to room temperature and forms the cured resin 5a. As the thermoplastic resin, a polymer such as an acrylic resin or a silicone resin can be used in addition to the above.

Next, although not shown, individual semiconductor elements 1 are made into chips along a grid line between chips by using a dicing saw. Next, as shown in FIG.
The bump electrodes 2 of the semiconductor element 1 are aligned so that they can be connected to the substrate electrodes 7 on the substrate 6. A glass substrate is used for the substrate 6, and ITO (Indium) is used for the substrate electrode 7.
m Tin Oxide) was used. And FIG.
As shown in (d), the semiconductor element 1 is pressed against the substrate 6 and the bump electrode 2 is pressed against the substrate electrode 7, and heating is performed to melt the resin 5. As a result, the resin 5 between the end surface of the bump electrode 2 and the substrate electrode 7 disappears, and the bump electrode 2 of the semiconductor element 1 and the substrate electrode 7 are connected and conducted.

In this state, air is blown and cooling is performed to fix the semiconductor element 1 on the substrate 6, and the cured resin 5a is formed so as to cover the bump electrodes 2 and the substrate electrodes 7. In the above example, the epoxy-based thermoplastic resin 5
Was heated and melted, applied to the bump electrode 2 and cured, but the resin may be a conductive, non-conductive or anisotropic conductive resin. Alternatively, a thermosetting resin which is a mixture of a main agent and a curing agent and which reacts when heated may be used. Alternatively, an ultraviolet curable resin may be used. Also,
The bump electrode 2 is not limited to Au, but Cu, C
Any metal having conductivity such as r and capable of being formed by plating may be used. However, it is desirable that the bump electrodes 2 to be used have uniform diameters, and that the bump electrodes 2 are elastically deformed or the resin 5 to which they are adhered has elasticity in order to obtain conductive reliability in connection. There is a need. Further, the substrate 6 is not limited to glass, and can be used for glass substrates, metal substrates, resin substrates and the like.

[0012]

As described in detail above, according to the present invention, the following effects can be obtained. Since the uncured resin is selectively formed on the bump electrode part of the semiconductor element, the position can be easily recognized by the camera, and it becomes difficult to confirm the mounting position by the resin coating process on the substrate and the resin coating. The increase in the alignment time can be eliminated, and the manufacturing cost can be reduced.

Since the semiconductor element can be fixed and the electrodes can be connected to each other by using a resin which is hardened at a low temperature when connecting to the substrate, flip chip mounting of the semiconductor element on the substrate material having low heat resistance is required. You can

[Brief description of drawings]

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

FIG. 2 is a sectional view of a conventional semiconductor element mounting process.

[Explanation of symbols]

 1, 21 Semiconductor element 2 Bump electrode 3 Passivation film 4 Glass mask 5 Resin 5a Cured resin 6, 23 Substrate 7, 24 Substrate electrode 22 Solder bump 25 Solder dam 26 Pre-solder

Claims (1)

[Claims] 1. A semiconductor element mounting method for flip-chip mounting a semiconductor element on a substrate, wherein uncured resin is selectively formed on bump electrode portions of the semiconductor element, and then the semiconductor element is pressed onto the substrate. A flip-chip mounting method for a semiconductor device, characterized in that the resin is cured while the bump electrode is pressed against the substrate electrode.