JPH10335336A - Solder bump structure and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide solder bump structures and manufacture thereof whereby no crack occurs at solder bumps, even when a thermal stress occurs and the structures can be easily be separated from a substrate after mounting. SOLUTION: A semiconductor device 5 composed of a semiconductor chip, etc., has a wiring pattern 22 on its main surface 21, solder bumps 4 disposed on terminals of the pattern 22, and a reinforcing resin material 7 which is disposed on the main surface 21 of the device 5 between solder bumps 25 and bonded to approximately the lower semispherical part 24 of each solder bump. On at least a part of approximately the upper semi-spherical part 23 of each solder bump other resin 3 having no affinity with the resin material 7, remains.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solder bump structure used in a semiconductor device and a method of manufacturing the same, and more particularly to a solder bump reinforcing structure of a BGA type semiconductor device. .

[0002]

2. Description of the Related Art Conventionally, in a semiconductor device using a small solder bump portion such as a BGA type CSP (chip size package) or a flip chip as an external electrode, if used for a long period of time, a crack is formed at the base of the solder bump portion. Sometimes occurred. The reason why cracks are formed at the base of the solder bumps in this way is considered to be due to a large difference between the thermal expansion coefficient of the semiconductor device and the thermal expansion coefficient of the semiconductor substrate to be mounted.

[0003]

As shown in FIG. 2, the above-described problem is caused by filling the reinforcing resin 10 between the semiconductor device 5 including an appropriate chip and the mounting substrate 11, and by using a resin. To some extent, it can be eliminated by preventing a large displacement. However, as shown in FIG. 2, the semiconductor device 5 is mounted on a mounting substrate 11 with a thermosetting resin 10 for reinforcement.
If a defect is detected in the semiconductor device 5 or the mounting substrate 11 in a later step, it is impossible to separate them, so that the defective product is replaced with another product. There is a problem that it cannot be mounted. Therefore, the yield has been reduced.

In the method disclosed in Japanese Patent Application Laid-Open No. Hei 8-236654, a paste-like resin is poured between solder bumps and then heat-treated to form a resin layer, or the paste-like resin is mixed in the paste-like resin. A method has been proposed in which a solder bump is immersed, then heat-treated to form a resin layer, and then polished until the bump appears.

However, in the conventional method, when the solder bump size is small and the pitch is small,
If resin is poured between the solder bumps, there is a problem that the resin also covers the upper surface of the solder bumps, causing a mounting failure. In addition, processing accuracy is required to perform polishing until the bumps appear, There was a problem that it also took.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a semiconductor device in which a solder bump is used as an external electrode. When an abnormality is detected in the device, the two can be easily separated from each other, and for example, a solder bump portion so that a chip can be removed from a substrate is provided, or a method of manufacturing a solder bump structure is provided. Is what you do.

[0007]

In order to achieve the above-mentioned object, the present invention employs the following basic technical structure. That is, as a first aspect of the present invention, a plurality of solder bump groups provided on a terminal portion of a wiring pattern provided on a main surface of a semiconductor device, and between the solder bumps, Along with being disposed on the main surface, is formed of a reinforcing resin material joined to only the substantially lower hemisphere of each solder bump, and at least a portion of the substantially upper hemisphere of each solder bump includes the The reinforcing resin material is a bump structure in which other resin having no affinity remains, and as a second aspect according to the present invention,
A method of manufacturing a solder bump structure used in a semiconductor device having a solder bump as an external electrode, the manufacturing method comprising: a reinforcing resin material fixed to a solder bump portion on a lower surface of a flexible material having a flat lower surface. Transferring a resin material for a mask having no affinity with the solder bump portion, pressing the lower surface of a rubber material of the flexible material against the upper surface of the solder bump portion, and transferring and applying the resin material for a mask to the upper hemispheric surface of the solder bump portion. And a step of supplying a predetermined amount of a reinforcing resin material fixed to the solder bumps between the solder bumps,
Pressing the solder bump portion surface with a pressing material having a flat lower surface,
Bonding and fixing the reinforcing resin material only to the substantially lower hemisphere portion of each of the solder bump portions.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The solder bump structure according to the present invention has the above-mentioned technical configuration, and therefore, the upper half of the spherical portion of the solder bump portion provided on the semiconductor mounting device. Has no reinforcing resin, while the lower half of the spherical portion of the solder bump has the reinforcing resin firmly bonded and fixed as in the prior art. Even when thermal stress occurs after mounting the semiconductor device on a predetermined semiconductor substrate, cracks and the like do not occur in the lower portion of the solder bump portion, while the spherical portion of the solder bump portion does not. Since the reinforcing resin does not exist in the upper half, the semiconductor device and the mounting substrate can be easily separated if necessary.

Further, in the present invention, a masking resin material having no affinity with the reinforcing resin material is transferred and applied to the upper hemisphere of the solder bump with a rubber material or the like, so that the reinforcing resin material is supplied. When the reinforcing resin material is spread out to the outside of the solder bump on the outermost periphery of the semiconductor device by applying pressure with a rubber material, the reinforcing resin material does not cover the upper surface of the solder bump, but only on the base of the solder bump. A resin material can be applied.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a solder bump structure and a method of manufacturing the same according to the present invention. FIG.
(D) is a cross-sectional view schematically showing the structure of a specific example of the solder bump portion 20 according to the present invention. A plurality of solder bump groups 4, 4 ', 4 ",... Arranged on the terminals of the wiring pattern 22 provided thereon.
.. And the reinforcing resin material 7 which is arranged on the main surface 21 of the semiconductor device 5 between the solder bumps 25 and is joined only to the substantially lower hemisphere portion 24 of each solder bump. And the respective solder bump portion groups 4,
A solder bump structure 20 in which another resin 3 having no affinity for the reinforcing resin material 7 remains on at least a part of the substantially upper hemispherical portion 23 of 4 ′, 4 ″. It is shown.

That is, in the solder bump structure 20 according to the present invention, the solder bump portion groups 4, 4 ', 4 "
... Are mounted on the wiring terminals of the main surface 21 on which the wiring pattern of the semiconductor device 5 composed of an appropriate chip is provided, and are substantially lower half of the spherical solder bump portion. In FIG. 1, a reinforcing resin for fixedly holding the solder bump portion 4 on the surface of the semiconductor device 5 is provided on the spherical portion of FIG.
As shown in (D), a configuration is adopted in which the support resin is arranged, while the reinforcing resin does not exist on the upper half spherical portion of the spherical body of the solder bump portion 4. Since the resin (mask resin) that has a slight affinity with the reinforcing resin remains in at least a part thereof, the semiconductor device 5 is mounted on the appropriate semiconductor substrate 11 by a face-down method. Even when mounted on the semiconductor substrate, the spherical surface 23 of the upper half of the solder bump portion 4 can be connected to the terminal portion of the wiring portion provided on the semiconductor substrate without the intervention of the reinforcing resin.

Therefore, if the semiconductor device 5 is defective, the semiconductor device 5 and the semiconductor substrate 11 are re-heated to a temperature higher than the melting point of the solder constituting the solder bump portion. It can be easily separated. The reinforcing resin used in the present invention is not particularly specified, and a thermoplastic resin, a thermosetting resin, and the like generally used conventionally can be used. The resin having no resin is not particularly limited, and a material generally having no affinity with the above-mentioned reinforcing resin may be used.

Next, an example of a method for manufacturing a solder bump structure according to the present invention will be described in detail with reference to FIGS. 1 (A) to 1 (D). That is, in the method of manufacturing a solder bump structure according to the present invention, first, the solder bump surface of the semiconductor device 5 having the solder bumps 4 as external electrodes is set to the upper surface, and the masking resin material 3 having no affinity with the reinforcing resin material 7 is used. Is applied to the upper surface of the solder bumps, the masking resin material 3 is supplied on a rotatable flat disk, a squeegee is applied from the center to the outer peripheral edge, the gap between the disk surface and the squeegee is fixed, and the disk is rotated. The mask resin material 3 is spread to a certain thickness on the disk. Next, the rubber material 2 having a flat lower surface is brought into contact with the mask resin material 3 on the disk, and the mask resin material 3
Is transferred.

The lower surface of the rubber material 2 is pressed against the surface of the solder bump group 4 of the semiconductor device 5, as shown in FIG.
The mask resin material 3 is transferred to the upper hemisphere of the solder bump 4. Then, the masking resin material 3 is once dried by heating to form a film of the masking resin material 3 on the upper hemisphere of the solder bump 4.

Next, as shown in FIG. 1B, a reinforcing resin material 7 is supplied to the solder bump 4 surface of the semiconductor device 5 by a dispenser 6, and as shown in FIG. Another flat rubber material 9 is pressed using an appropriate pressing head 8 to spread the reinforcing resin material 7 to the position of the outermost solder bumps 4 of the semiconductor device 5, The space 25 between the groups is completely filled with the reinforcing resin material.

However, in the present invention, since the material having no affinity with the reinforcing resin material 7 provided beforehand in the upper hemispherical portion 23 of the solder bump portion 4 is provided, the reinforcing resin material is not used. The material 7 and the upper hemispherical portion 23 of the solder bump portion 4 are not bonded to each other, and accordingly, FIG.
As shown in (D), finally, the reinforcing resin material 7 is heated and cured, and the reinforcing resin material 7 is contracted, so that the reinforcing resin material 7 is attached to the base, which is the lower hemispherical portion 24 of the solder bump 4. The material 7 is firmly adhered and fixed so as to form a support portion made of a resin film. The reinforcing resin material 7 is removed from the upper hemisphere portion 23 of the bump portion 4 and has an affinity with the reinforcing resin material 7. It has a state in which a material having no properties remains at least partially.

In the present invention, the material used to transfer the mask resin material is not limited to a rubber material, but can adsorb the mask resin material.
Any material can be used as long as the material has elasticity and flexibility so that it can come into contact with the surface of the solder bump portion 4 while forming a predetermined concave state when receiving a predetermined pressing force. It is.

Similarly, the rubber material used when the reinforcing resin material 7 is pushed from the surface of the semiconductor device 5 into the space between the solder bumps 4 is not limited to this, but is appropriately specified. Any material having the above elasticity and flexibility can be used. That is, in the method of manufacturing a solder bump structure according to the present invention, for example, a mask resin material having no affinity with the reinforcing resin material fixed to the solder bump portion is transferred to the lower surface of a flexible material having a flat lower surface. A step of pressing the lower surface of the rubber material of the flexible material against the upper surface of the solder bump portion to transfer and apply the resin material for a mask to the upper semi-spherical surface of the solder bump portion; Supplying a predetermined amount of a reinforcing resin material fixed to the portion, and pressing the surface of the solder bump portion with a pressing material having a flat lower surface, and applying the reinforcing resin material only to a substantially lower hemisphere portion of each solder bump portion. And a step of bonding and fixing the same.

Further, more specific examples of the method for manufacturing a solder bump structure according to the present invention include, for example,
In a semiconductor device having a solder bump as an external electrode, a step of transferring a masking resin material having no affinity with a reinforcing resin material to a lower surface of a rubber material having a flat lower surface, Pressing the resin material onto the solder bumps to transfer and apply the resin material for mask to the upper hemispherical surface of the solder bumps; heating and drying the resin material for mask; and applying a reinforcing resin material to the solder bump surface. A step of supplying a fixed amount, a step of pressing the solder bump surface with a rubber material having a flat lower surface, and a step of spreading the reinforcing resin material to outside the outermost solder bumps of the semiconductor device; and heating and curing the reinforcing resin material And a step of performing

[0020]

According to the present invention, since the above-mentioned technical structure is employed, a resin material for a mask having no affinity with a reinforcing resin material is formed by using a flexible material such as a rubber material to form a solder bump. After supplying the reinforcing resin material by transfer coating on the upper hemisphere, pressurize with a flexible material such as the rubber material and spread the reinforcing resin material to the outside of the outermost solder bump of the semiconductor device. In addition, there is an effect that the reinforcing resin material can be applied only to the base of the solder bump without covering the upper surface of the solder bump with the reinforcing resin material.

[Brief description of the drawings]

FIGS. 1A to 1D are explanatory views showing the procedure of a specific example of a method for manufacturing a solder bump structure according to the present invention.

FIG. 2 is a diagram for explaining a conventional mounting state of a semiconductor device and a semiconductor substrate.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 transfer head 2 rubber material 3 mask resin material 4 solder bump 5 semiconductor device 6 dispenser 7 reinforcing resin material 8 pressurizing head 9 rubber material 10 resin 11 mounting substrate 20 Solder bump structure 21: Main surface of semiconductor device 22: Wiring pattern of semiconductor device 23: Upper hemisphere of solder bump 24: Lower hemisphere of solder bump 25: Space between solder bumps

Claims (4)

[Claims] A plurality of solder bumps provided on a terminal portion of a wiring pattern provided on a main surface of the semiconductor device; and a plurality of solder bump groups arranged on the main surface of the semiconductor device between the solder bumps. A reinforcing resin material joined to only the lower hemisphere portion of each solder bump,
A solder bump structure, characterized in that at least a part of the upper hemispherical portion of each of the solder bumps has another resin having no affinity with the reinforcing resin material remaining. 2. The solder bump structure according to claim 1, wherein said solder bump portion is joined to a connection terminal of a chip mounted on said semiconductor substrate. 3. A method of manufacturing a solder bump structure used in a semiconductor device using a solder bump as an external electrode, the manufacturing method comprising: fixing a solder bump portion to a lower surface of a flexible material having a flat lower surface. Transferring a masking resin material having no affinity with the reinforcing resin material, and pressing the lower surface of the rubber material of the flexible material against the upper surface of the solder bump portion, and applying the masking resin material on the solder bump portion. Transferring and applying a predetermined amount of a reinforcing resin material fixed to the solder bump portion between the solder bump portion, and pressing the solder bump portion surface with a pressing material having a flat lower surface,
Bonding and fixing the reinforcing resin material only to the substantially lower hemispherical portion of each of the solder bump portions. 4. A semiconductor device using a solder bump as an external electrode, a step of transferring a masking resin material having no affinity with a reinforcing resin material onto a lower surface of a rubber material having a flat lower surface; Pressing the rubber material against the solder bumps to transfer and apply the resin material for mask to the upper hemisphere of the solder bumps; heating and drying the resin material for masks; reinforcing the solder bump surface A step of supplying a predetermined amount of resin material for use, a step of pressing the solder bump surface with a rubber material having a flat lower surface, and spreading a reinforcing resin material to outside the outermost solder bumps of the semiconductor device; 4. The method for manufacturing a solder bump structure according to claim 3, further comprising a step of heating and curing the resin material.