JP2606110B2 - Multilayer substrate and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer substrate used for flip-chip mounting of a semiconductor and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, flip-chip mounting of this type has been widely used because it has advantages such as lower cost and higher productivity than manual bonding using wires.

FIG. 5 is a cross-sectional view for explaining a conventional substrate used for flip-chip mounting and a mounting method thereof.
As shown in FIG. 5A, an electrode 2 is provided on a semiconductor 11. Next, in FIG. 5B, first, a spherical solder bump 13 is formed on the electrode 12. Semiconductor 11
Is mounted on a substrate 14 provided with bonding pads 15 that are electrically connected to the electrodes 12 via the solder bumps 13 (note that in FIG.
Only the layer substrate is shown as substrate 14). Further, a thick film glass 16 for preventing the molten solder bumps 13 from flowing into circuits and patterns other than the bonding pads 15 when the semiconductor 11 is mounted on the substrate 14 is formed on the substrate 14. The thick film glass 16 is formed by applying a glass paste and firing after the substrate firing process on the multilayer substrate.

In such a configuration, the semiconductor 11 is superimposed on the substrate 14 so that the solder bumps 13 are in contact with the bonding pads 15, and the semiconductor 11 is heated from a lower surface of the substrate. The heating melts the solder bumps, and the electrodes 12 and the bonding pads 15 are electrically connected.

A substrate on which this type of semiconductor is mounted and a method of manufacturing the same are disclosed in, for example, Japanese Patent Application Laid-Open No. H4-171891, published June 19, 1992 (Document 1).
The described structures and manufacturing methods are known. This document 1
Has a recess at the center of the surface of the multilayer printed wiring board,
There is described a multilayer printed wiring board provided with copper-plated surface mounting pads on the entire surface including the lower surface and side surfaces of a concave portion having a U-shaped vertical section.

[0006]

However, since the substrate used for flip-chip mounting shown in FIG. 5 forms a thick film glass after the substrate is baked, the substrate must be baked twice and the manufacturing process Is complicated. In addition, although the positional relationship between the bonding pad and the thick film glass needs to be accurately adjusted, the alignment is not possible because the green sheet constituting the substrate shrinks at the time of firing the substrate.

On the other hand, the substrate and the method for manufacturing the substrate described in Document 1 have a problem that the manufacturing process is very complicated and the production efficiency is reduced.

An object of the present invention is to solve the above-mentioned problems and to provide a flip-chip mounting substrate and a method of manufacturing the flip-chip mounting substrate, in which the alignment between the semiconductor and the substrate is easy and the manufacturing is easy.

[0009]

Therefore, according to the present invention, in a multilayer substrate, a hole is formed in a substrate of a layer higher than a substrate having a bonding pad matching a position of a bonding pad electrically connected to a bump electrode. The above-mentioned object is achieved by providing.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail with reference to the drawings.

First, a method of flip-chip mounting a semiconductor and a multilayer substrate will be described. Hereinafter, a multi-layer substrate composed of three layers will be described as an example so that the electrical connection structure and method between the semiconductor and the bonding pads on the multi-layer substrate, which are features of the present invention, can be easily understood.

FIG. 1 is a sectional view for explaining a flip-chip mounting method of a semiconductor according to the present invention.

In FIG. 1, FIG. 1A shows a semiconductor 1 to be mounted, and a semiconductor similar to the semiconductor 11 shown in FIG. 5 is used as a conventional technique. Figure (b) shows solder bump 3
1 shows a semiconductor 1 on which a semiconductor layer 1 is formed and a ceramic multilayer substrate 4 on which the semiconductor 1 is mounted. In FIG.
The first layer 7 has a hole 6 at a position corresponding to the bonding pad 5 provided on the second layer 8. Although not shown in the figure, the second and third layer substrates 8 and 9 are electrically connected by filling the via holes provided in each layer with a conductive paste and firing the substrate. . The first and second layer substrates 7 and 8 are joined by the above-described firing.

In such a configuration, first, the solder bump 3 is inserted into the hole 6 so as to be in contact with the bonding pad 5, and the semiconductor 1 and the multilayer substrate 4 are inserted in the direction of the arrow in FIG.
And overlap. Next, by applying heat to the multilayer substrate 4 from below, the solder bumps 3 are melted, and the electrodes 2 and the bonding pads 5 are electrically connected. At this time, the second
The molten solder does not flow into circuits and patterns other than the bonding pads 5 provided on the layer 8. this is,
The portion of the first layer 7 other than the hole 6 is a conventional technology shown in FIG.
This is because it has the same action as the thick film glass 16 described in (1).

Next, a multilayer substrate and a method of manufacturing the same according to the present invention will be described with reference to FIGS.

First, the green sheet 1 shown in FIG.
Holes 6 are formed by punching holes at 0 to obtain a first layer substrate 7. Next, as shown in FIG. 1C, a circuit pattern 18 is formed on the second layer substrate 8, and a bonding pad 5 is provided in a portion of the semiconductor 1 that contacts the solder bump 3. Further, via holes 17 for obtaining electrical connection with the third layer substrate 9 are provided at the ends of the circuit pattern 18, and the inside is filled with a conductive paste such as tungsten. A circuit pattern 18 is provided on the third layer substrate 9 shown in FIG. 4D in the same manner as the second layer substrate 8, and the connection portion 1 is provided at a position corresponding to the position of the via hole 17 on the second layer substrate.
9 is provided.

Next, the first to third layer substrates 7 shown in FIG.
9 are stacked and the laminated substrate is fired to obtain a multilayer substrate 4 including first to third layers. The method of laminating the first layer substrate 7 having the holes 6 and the second layer substrate 8 is as shown in FIG. 3 so that the positions of the holes 6 and the bonding pads 5 are aligned in the direction of the arrow in FIG. Laminate.

Next, a second embodiment of the present invention will be described with reference to FIG. As shown in FIG. 2B, bonding pads 5 are provided on the second and third layer substrates 7 and 8 of the multilayer substrate 4. The first and second solder bumps 3 and the bonding pads 5 are electrically connected to each other.
Holes 6 are provided in layer substrates 7 and 8. However, since a circuit pattern is formed on the second substrate 8, the holes 6 are provided so that the circuit patterns do not cross the holes 6. The method of forming the bonding pads 5, holes 6, and circuit patterns on each layer substrate is exactly the same as in the first embodiment. The same applies to the mounting method.

[0019]

As described above, in the multilayer substrate according to the present invention, bonding pads for electrically connecting the bump electrodes are provided in the lower layer, and holes are provided in the upper layer at positions corresponding to the bonding pads. Has been
Unlike the related art, it is not necessary to form a thick film glass for preventing solder flow on the upper layer, and a multilayer substrate can be obtained by one firing of the substrate. Further, there is no need to match the positional relationship between the bonding pad and the thick film glass. For this reason, the manufacturing process of the multilayer substrate for flip-chip mounting can be greatly simplified, and there is an effect that the production efficiency is improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating flip-chip mounting of a semiconductor in a case where a bonding pad is provided only on a second layer substrate for explaining an embodiment of the present invention.

FIG. 2 is a perspective view illustrating a multilayer substrate according to one embodiment of the present invention and a method for manufacturing the same.

FIG. 3 is a perspective view showing a state in which a first layer substrate of the multilayer substrate shown in FIG. 2 is stacked;

FIG. 4 is a cross-sectional view illustrating a multi-layer board having bonding pads on second and third-layer boards of a multi-layer board for explaining a second embodiment of the present invention and a mounting method thereof.

FIG. 5 is a cross-sectional view illustrating a substrate used for conventional flip chip mounting and a mounting method thereof.

[Explanation of symbols]

 Reference Signs List 1 semiconductor 2 electrode 3 solder bump 4 multilayer substrate 5 bonding pad 6 hole 7 first layer substrate 8 second layer substrate 9 third layer substrate 10 green sheet 11 semiconductor 12 electrode 13 solder bump 14 substrate 15 bonding pad 16 thick glass 17 Via hole 18 Circuit 19 Connection

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location H05K 3/34 507 H01L 23/12 N

Claims (3)

(57) [Claims] 1. A third layer substrate having a first bonding pad connected to a semiconductor electrode, and a first bonding pad disposed on the third layer substrate and corresponding to a first bonding pad at a position corresponding to the first bonding pad. And a second-layer substrate having a second bonding pad connected to the electrode at a position different from the position where the first hole is formed, further comprising: And a second hole at a corresponding position of the first hole and the second bonding pad.
A multilayer substrate, comprising: a first layer substrate having a hole. 2. The flip- chip mounting structure of a semiconductor on a multilayer substrate, wherein the solder bumps on the electrodes provided on the semiconductor are formed on the first hole and the solder hole on the multilayer substrate according to claim 1. The multilayer board is heated and cooled by inserting the electrodes into the second holes, and the electrodes are connected to the first bonding pads and the second bonding pads by the solder bumps.
A flip- chip mounting structure, wherein the flip- chip mounting structure is electrically connected to the bonding pad. 3. The multi-layer substrate according to claim 1, wherein at least the second layer substrate and the third layer substrate have via holes, and the via holes are filled with a conductive paste; 2. The method according to claim 1, further comprising: aligning and stacking the substrates up to the third layer; and firing the three substrates from the first layer to the third layer. 3. Production method of a multilayer substrate.