JPH1167772A - Leveling method for protruding electrode of semiconductor element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make leveling height of protruding electrodes uniform with high precision by reducing the variance in leveling height of the protruding electrodes of a semiconductor element, when the height of a plurality of protruding electrodes formed on the semiconductor element is made uniform by sandwiching the semiconductor element between two plates and adding a load. SOLUTION: When the height of a plurality of protruding electrodes 1 formed on a semiconductor element 2 is made uniform by sandwiching a semiconductor element 2 between two plates 3 and 4 and adding a load, a material 5 that distorts elastically is inserted inbetween a surface 2a of the semiconductor element 2, on which the protruding electrode 1 is not formed and a leveling plate (on the lower side) 4, and under this condition, the tip of the protruding electrode 1 is squashed by adding the load, so that the height of the plurality of protruding electrodes 1 is leveled uniformly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for leveling bump electrodes of a semiconductor device in a process of assembling the semiconductor device.

[0002]

2. Description of the Related Art In recent years, the mounting methods of semiconductor elements have become higher in density, and flip-chip mounting methods capable of realizing the highest density mounting have been widely used.

In the flip-chip mounting method of directly connecting the projecting electrodes of the semiconductor element and the wiring electrodes of the substrate, if the heights of the projecting electrodes of the semiconductor element are not uniform, the projecting electrodes of the semiconductor element are attached to the wiring electrodes of the substrate. Since a portion where the electrode is not in contact is generated and a problem such as poor contact occurs, it is conventionally necessary to align the heights of the protruding electrodes of the semiconductor element with high precision.

As shown in FIG. 7, a conventional method for leveling a protruding electrode of a semiconductor device is such that a semiconductor device 2 is placed between two leveling plates which are adjusted closer to parallel.
Is placed on a leveling plate (lower side) 4 with the surface 2b on which the protruding electrode 1 is formed upward, and the protruding electrode 1 of the semiconductor element 2 is sandwiched by the leveling plate (upper side) 3 to apply a load. Thereby, the tip of the protruding electrode 1 is crushed to make the height uniform.

[0005]

However, in the conventional method of leveling the protruding electrodes of a semiconductor device, a plurality of protruding electrodes 1 to be leveled are determined depending on the parallelism with the leveling plates (upper) 3 and (lower) 4. The accuracy of the height is affected. Specifically, the adjustment of the parallelism between the leveling plates (upper) 3 and (lower) 4 is about 4 μm.
m is the limit, and the height of the protruding electrode 1 is leveled in the state of the parallelism. Therefore, the deviation of the parallelism is directly reflected, and the variation in the height of the plurality of protruding electrodes 1 is about As a result, there is a problem that the leveling height of the plurality of bump electrodes 1 varies.

Further, as the size of the semiconductor element increases, the leveling plate used also increases, and the processing accuracy of the leveling plate deteriorates. Therefore, the processing accuracy of the leveling plate and the parallelism of the leveling plates 3 and 4 increase. There is a problem that the leveling height of the plurality of bump electrodes 1 varies.

When a foreign substance or the like is present under the semiconductor element 2, the leveling of the projection electrode 1 of the semiconductor element 2 is performed in a state where the semiconductor element 2 is inclined by the foreign substance or the like. There is a problem that the height varies.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of leveling a protruding electrode of a semiconductor device, which makes the leveling height of the protruding electrode of the semiconductor device uniform with high precision.

[0009]

According to the present invention, there is provided a method for leveling a protruding electrode of a semiconductor device, the method comprising: applying a load with a semiconductor device sandwiched between two plates to apply a plurality of protruding electrodes formed on the semiconductor device. In making the height uniform, a material that is elastically deformed is interposed between the surface of the semiconductor element on which the protruding electrode is not formed and one of the plates, and in this state, the load is applied to the protruding electrode. Leveling the height.

According to the method for leveling the protruding electrodes of the semiconductor device of the present invention, the leveling height of the plurality of protruding electrodes of the semiconductor device can be made uniform with high precision.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In a method according to a first aspect of the present invention, the height of a plurality of projecting electrodes formed on a semiconductor element is increased by applying a load with a semiconductor element sandwiched between two plates. Upon uniforming, a material that is elastically deformed is interposed between the surface of the semiconductor element on which the protruding electrode is not formed and one of the plates, and the load is applied in this state to increase the height of the protruding electrode. The leveling method of the protruding electrode of the semiconductor element to be leveled, by interposing an elastically deformable material between the surface of the semiconductor element where the protruding electrode is not formed and one of the plates,
The leveling height of the projecting electrodes of a plurality of semiconductor elements is absorbed by a material that elastically deforms so that the surface on which the projecting electrodes of the semiconductor element are formed and the plate in contact with the surface are more parallel to each other. Can be uniformed with high precision. Even when the semiconductor element is tilted due to the presence of foreign matter or the like under the semiconductor element, the inclination of the semiconductor element is reduced by the elastically deformable material, and the leveling height of the protruding electrodes of the semiconductor element is made uniform with high precision. can do.

According to a second aspect of the present invention, a method is provided for applying a load with a semiconductor element sandwiched between two plates to equalize the heights of a plurality of protruding electrodes formed on the semiconductor element. A plurality of semiconductor elements are arranged on a tape-shaped elastically deformable material passing between the plates, and the semiconductor elements are transferred each time the load is applied and leveling of the height of the protruding electrode is performed. And a leveling method of the protruding electrode of the semiconductor element which repeats leveling the height of the protruding electrode by positioning the next semiconductor element between the plates, and a tape-like elasticity passing between the two plates. Since a plurality of semiconductor elements are arranged on a deformable material, and a level is applied to the plurality of semiconductor elements sequentially by applying a load, the same effect as described above is obtained. It can implement leveling of the height of the projecting electrodes of a plurality of semiconductor elements efficiently.

According to a third aspect of the present invention, there is provided a method for leveling a protruding electrode of a semiconductor device according to the first or second aspect, wherein the elastically deformable material is a sticky material. When leveling the height of the plurality of bump electrodes of the semiconductor element, the semiconductor element can be more firmly fixed by the adhesiveness of the elastically deformable material, and comes into contact with the surface on which the bump electrode of the semiconductor element is formed and the surface. The deviation in parallelism is absorbed by an adhesive and elastically deformable material so that the plate becomes more parallel to the plate, and the leveling height of the projecting electrodes of the plurality of semiconductor elements can be made uniform with high precision. Further, when transferring a plurality of semiconductor elements by making the elastically deformable material into a tape shape, the semiconductor elements can be transferred in a fixed state by the adhesiveness of the elastically deformable material.

According to a fourth aspect of the present invention, there is provided a method for equalizing the height of a plurality of protruding electrodes formed on a semiconductor element by applying a load with a semiconductor element sandwiched between two plates. A projection provided on the lower plate is located at an intersection of a perpendicular line from a center of gravity generated by the load between the plurality of projection electrodes and a surface of the semiconductor element on which the projection electrode is not formed or at a position close to the intersection. It is a method of leveling the protruding electrode of the semiconductor element, which is placed so as to abut and applies the load in this state to level the height of the protruding electrode, and the protruding portion provided on the lower plate, A semiconductor element is mounted by applying a load between the plurality of protruding electrodes so as to abut on an intersection of a perpendicular line from a center of gravity generated by the load and a surface on which the protruding electrodes are not formed or a position close to the intersection. Butt The surface of the semiconductor element on which the protruding electrode is formed is inclined so that the surface on which the electrode is formed and the plate in contact with the surface are more parallel to each other. The leveling height of the electrode can be made uniform with high precision.

[0015] Even when foreign matter or the like exists under the semiconductor element, if the foreign matter is smaller than the height of the projection provided on the lower plate, the influence of the foreign matter or the like on the leveling of the projection electrode of the semiconductor element can be obtained. Hardly ever.

Specifically, the center of the surface of the semiconductor element on which the protruding electrodes are formed or the center of the surface surrounded by the plurality of protruding electrodes is determined, and the protruding portion provided on the lower plate is positioned from the center. Is placed so as to abut on the intersection of the perpendicular line of the semiconductor element and the surface of the semiconductor element on which the protruding electrode is not formed or in the vicinity thereof, and in this state, the load is applied to level the height of the protruding electrode. I do.

According to the present invention, the intersection of the vertical line from the center of the surface of the semiconductor element where the projecting electrodes are formed or the center of the surface surrounded by the plurality of projecting electrodes and the surface where the projecting electrodes are not formed or the intersection thereof. The same effect as described above can also be obtained by applying a load by placing the projection so that the projection abuts on the proximity position.

Hereinafter, a method for leveling a bump electrode of a semiconductor device according to the present invention will be described based on a specific embodiment. (Embodiment 1) As shown in FIG. 1, a plurality of layers formed on a semiconductor element 2 by applying a load with a semiconductor element 2 interposed between a leveling plate (upper side) 3 and a leveling plate (lower side) 4 When the height of the projecting electrode 1 is made uniform, the surface 2a of the semiconductor element 2 on which the projecting electrode 1 is not formed is formed.
A material 5 that is elastically deformed, for example, a polyimide sheet, is interposed between the protruding electrode 1 and the leveling plate (lower side) 4. This is a method of leveling the protruding electrodes of the semiconductor element to level the height uniformly.

If the thickness of the elastically deformable material 5 is too small, the elastically deformable material 5 will not be deformed until the parallelism is obtained. If the thickness is too large, the semiconductor element 2 will be elastically deformed when a load is applied. For example, the thickness was set to 10 μm to 30 μm since the load was not sufficiently applied due to sinking.

Other examples of the elastically deformable material 5 include urethane rubber and silicone rubber. Note that the semiconductor element 2
The height of the plurality of projecting electrodes 1 formed thereon is generally about 45
It is formed to about μm.

Even when the height of the projecting electrode 1 is leveled in a state where the parallelism between the leveling plate (upper) 3 and the leveling plate (lower) 4 is adjusted to be about 4 μm in parallel, the material 5 which is elastically deformed can be used. A material 5 that is elastically deformed so that the surface 2b of the semiconductor element 2 on which the protruding electrodes 1 are formed and the leveling plate (upper side) 3 are more parallel.
As a result, the deviation in parallelism is absorbed, and the variation in the height of the plurality of protruding electrodes 1 is about 2 μm.

When the semiconductor element 2 is tilted due to the presence of foreign matter or the like under the semiconductor element 2, the inclination of the semiconductor element 2 due to the foreign matter or the like can be reduced by the elastically deformable material 5. From the above, the elastically deformable material 5 is interposed between the surface 2a of the semiconductor element 2 on which the protruding electrode 1 is not formed and the leveling plate (lower side) 4, and a load is applied in this state. By leveling the heights of the projecting electrodes 1, the heights of the plurality of projecting electrodes 1 can be made uniform with high precision.

Further, even when a foreign substance or the like is present under the semiconductor element and the semiconductor element is tilted, the inclination of the semiconductor element due to the foreign substance or the like is reduced by the elastically deformable material, and the leveling height of the projecting electrode of the semiconductor element is reduced. Can be uniformed with high precision.

In the first embodiment, even when urethane rubber, silicone rubber, or the like is used as the material 5 that is elastically deformed, the same effect as described above is obtained. In the first embodiment, even when the elastically deformable material 5 is made of an adhesive material, for example, an acrylic adhesive or a silicone adhesive, the same effect as described above is obtained, and the elasticity of the elastically deformable material 5 is improved. Thereby, the semiconductor element 2 can be further fixed.

(Embodiment 2) As shown in FIG. 2, a semiconductor element 2 is sandwiched between a leveling plate (upper side) 3 and a (lower side) 4 and a load is applied on the leveling plate 3 (lower side). In making the heights of the plurality of projecting electrodes 1 uniform,
An elastically deformable material 5 on a continuous tape 6 passing between the leveling plates 3 (upper) and 4 (lower);
For example, a polyimide sheet is disposed, a plurality of semiconductor elements 2 are arranged on the elastically deformable material 5, and the semiconductor is applied each time the load is applied to level the plurality of bump electrodes 1. The element 2 is transferred from left to right, and the next semiconductor element 2 is positioned between the leveling plates (upper side) 3 and (lower side) 4 to repeatedly level the height of the protruding electrode 1. This is a leveling method of the protruding electrode.

Other examples of the elastically deformable material 5 include urethane rubber and silicone rubber. By the above,
The same effect as in the first embodiment can be obtained, and the leveling of the heights of the projecting electrodes of the plurality of semiconductor elements can be efficiently performed.

In the second embodiment, when the tape-shaped elastically deformable material 5 is used without using the tape 6, the same effect as described above is obtained. Embodiment 2
In the case where the tape-shaped elastically deformable material 5 without using the tape 6 is made of an adhesive material, for example, an acrylic adhesive or a silicone-based adhesive, the same effect as described above is exerted and the elastic deformation is performed. Due to the adhesiveness of the material, the semiconductor element can be more firmly transported.

(Embodiment 3) As shown in FIG. 3, a semiconductor element 2 is sandwiched between a leveling plate (upper side) 3 and a leveling plate (lower side) 4 to form a load on the semiconductor element 2. In making the heights of the plurality of protruding electrodes 1 uniform, the intersection of the perpendicular 2c from the center of gravity 2e generated by the load between the plurality of protruding electrodes 1 and the surface 2a on which the protruding electrodes 1 are not formed. Position (hereinafter, center of gravity position 2)
d) or a position close thereto is placed on the hemispherical projection 7 of the leveling plate (lower side) 4 so that the load is applied to level the height of the projection electrode 1 in this state. This is a leveling method of a bump electrode of a semiconductor element.

The position 2d of the center of gravity of the semiconductor element 2 is given by (Equation 1)
, The center of gravity 2e generated by the load between the plurality of protruding electrodes 1 (the point at which the sum of the distances of the respective protruding electrodes 1 × the total force is 0) is obtained, and the center of gravity 2e is determined by the surface on which the protruding electrode 1 is not formed. 2a. A plurality of protruding electrodes 1 of a semiconductor element 2 as shown in FIG.
, The center of gravity 2
d can be determined.

[0030]

(Equation 1) Here, n is the total number of projecting electrodes 1 Ln is the distance from the center of gravity 2 e generated by a load between the plurality of projecting electrodes 1 to each projecting electrode 1 Fn is the force applied to each projecting electrode 1 The center of gravity of the semiconductor element 2 The means for positioning so that the position 2d is located on the hemispherical projection 7 is, for example, after the semiconductor element 2 is sucked up by a suction nozzle, and as shown in FIG. 5, the positioning jig 8a and the positioning jig 8b The semiconductor element 2 is interposed therebetween, and the suction nozzle is removed. In some cases, it is moved in that state and positioned so as to be on the hemispherical projection 7. The positioning accuracy of the positioning means is ± 50 μm
Therefore, it is possible to sufficiently cover an allowable range (within about ± 100 μm) having the same effect as the case where the center of gravity 2d of the semiconductor element 2 is placed on the hemispherical projection 7 in contact. .

The material of the hemispherical projection 7 includes, for example, carbide SUS and Ti alloy.
Has a height of, for example, 20 μm or more and 100 μm or less.
From the above, the semiconductor element 2 is placed so that the center of gravity position 2d or a position close to the center of the semiconductor element 2 abuts on the hemispherical projection 7, and a load is applied in this state, thereby tilting the leveling plate (upper side) 3. At the same time, the surface 2b of the semiconductor element 2 on which the protruding electrodes 1 are formed becomes more parallel, a uniform load can be applied to the plurality of protruding electrodes 1, and the height of the plurality of protruding electrodes 1 can be adjusted with high precision. It can be made uniform.

In the third embodiment, the same effect can be obtained even if the hemispherical projection has a shape other than a hemisphere as long as the projection can be supported by a point or a small area. In the third embodiment, the shape of the semiconductor element 2 is, for example, a square or a rectangle, and as shown in FIG. 6A, each corner of the surface 2b of the semiconductor element 2 on which the bump electrode 1 is formed. An intersection 10a (the center of the surface on which the protruding electrode 1 is formed) of the line connecting 2f is determined. This intersection 10
When each of the protruding electrodes 1 is arranged at a position symmetrical with respect to the point a, a perpendicular 11 from the intersection 10a is
The same effect can be obtained by placing a load so that the intersection 9a with the surface 2a where no is formed or a position close to the intersection 9a abuts on the protrusion.

In the third embodiment, the semiconductor element 2 has a rectangular or square shape, for example, as shown in FIG.
As shown in FIG. 2B, an intersection 10b of a line connecting the protruding electrodes 1 on the surface 2b of the semiconductor element 2 on which the protruding electrodes 1 are formed.
(The center of the surface surrounded by the plurality of protruding electrodes 1) is determined. Each protruding electrode 1 is arranged at a position symmetrical with respect to the intersection 10b, and the intersection 10a and the intersection 10b of a line connecting each corner 2f of the surface 2b of the semiconductor element 2 forming the protruding electrode 1 are formed. If they do not match, the intersection 9 between the perpendicular 11 from this intersection 10b and the surface 2a on which the protruding electrode 1 is not formed
The same effect can be obtained by placing a load so that the position b or a position close to the position b abuts on the protrusion and applying a load.

[0034]

According to the present invention, a load is applied between the surface of the semiconductor element on which the protruding electrode is not formed and one of the plates with an elastically deformable material interposed therebetween to level the height of the protruding electrode. Thereby, the deviation of the parallelism is absorbed by the material which is elastically deformed so that the surface of the semiconductor element on which the protruding electrode is formed and the plate in contact with the surface become more parallel, and the plurality of protruding electrodes of the semiconductor element are absorbed. The leveling height can be made uniform with high precision.

Further, even when a foreign substance or the like is present under the semiconductor element and the semiconductor element is tilted, the inclination of the semiconductor element due to the foreign substance or the like is reduced by the elastically deformable material, and the leveling height of the projecting electrode of the semiconductor element is reduced. Can be uniformed with high precision.

Further, a material which is sticky and elastically deforms is
Protruding electrodes on the semiconductor element can be efficiently leveled by providing the semiconductor element on a continuous tape, adhering the semiconductor element thereon, and moving the tape. Also,
The projecting portion provided on the lower plate is brought into contact with the intersection of the perpendicular line from the center of gravity generated by the load between the plurality of projecting electrodes and the surface where the projecting electrodes are not formed or at a position close to the intersection. By mounting the semiconductor element between the two plates in a state where the semiconductor element is placed and supported at points, a uniform load can be applied to the protruding electrodes and leveling can be performed with high precision.

Further, the center of the surface of the semiconductor element on which the protruding electrodes are formed or the center of the surface surrounded by the plurality of protruding electrodes is determined, and the protruding portion provided on the lower plate is perpendicular to the center. And the surface where the protruding electrode is not formed is placed so as to be in contact with the intersection or at a position close to the intersection, and the semiconductor element is sandwiched between two plates while the semiconductor element is supported at a point, so that the Uniform load can be applied and leveling can be performed with high accuracy.

[Brief description of the drawings]

FIG. 1 is a side view of a semiconductor element according to a first embodiment of the present invention in a leveling state of a bump electrode;

FIG. 2 is a side view of a semiconductor device according to a second embodiment of the present invention in a leveling state of a bump electrode;

FIG. 3 is a side view of a semiconductor device according to a third embodiment of the present invention in a state where a protruding electrode is leveled;

FIG. 4 is an explanatory diagram for obtaining a position of a center of gravity according to the third embodiment;

FIG. 5 is a view showing an example of a semiconductor element positioning means according to the third embodiment;

FIG. 6 is a diagram showing an example of a center position according to the third embodiment;

FIG. 7 is a side view showing a leveling state of a protruding electrode of a conventional semiconductor element.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Projection electrode 2 Semiconductor element 2a Surface of semiconductor element on which projection electrode is not formed 2b Surface of projection of semiconductor element on which projection electrode is formed 2c Perpendicular line 2d Center of gravity position 2e Center of gravity generated by load between plural projection electrodes 2f Semiconductor Element corner 3 Leveling plate (upper side) 4 Leveling plate (lower side) 5 Material that elastically deforms 6 Tape 7 Spherical projection 8a Positioning jig 8b Positioning jig 9a, 9b Intersection of surfaces on which no projection electrode is formed 10a Center of the surface forming the protruding electrode 10b Center of the surface surrounded by the protruding electrode 11 Perpendicular

Claims (5)

[Claims] When a load is applied across a semiconductor element between two plates to equalize the height of a plurality of projecting electrodes formed on the semiconductor element, the projecting electrodes of the semiconductor element are formed. A method of leveling a protruding electrode of a semiconductor element, wherein a material that elastically deforms is interposed between a surface that is not covered and one of the plates, and the height of the protruding electrode is leveled by applying the load in this state. 2. A tape-like member that passes between the plates when a load is applied across a semiconductor element between two plates to equalize the heights of a plurality of protruding electrodes formed on the semiconductor element. A plurality of semiconductor elements are arranged on a material that is elastically deformed, and each time the load is applied to level the height of the protruding electrode, the semiconductor element is transferred, and the next semiconductor element is placed between the plates. And a method for leveling the protruding electrode of the semiconductor device, which repeats leveling the height of the protruding electrode by positioning the protruding electrode. 3. The method according to claim 1, wherein the elastically deformable material is a sticky material. 4. A projection provided on a lower plate when a height is applied to a plurality of projection electrodes formed on the semiconductor element by applying a load with a semiconductor element sandwiched between two plates. The semiconductor element is placed between the plurality of protruding electrodes so as to abut on an intersection of a perpendicular line from a center of gravity generated by the load and a surface of the semiconductor element on which the protruding electrodes are not formed or a position close to the intersection. A leveling method for projecting electrodes of a semiconductor device, wherein the height of the projecting electrodes is leveled by applying the load. 5. A step of applying a load with a semiconductor element sandwiched between two plates to equalize the height of a plurality of projecting electrodes formed on the semiconductor element, forming the projecting electrodes of the semiconductor element. The center of the surface or the center of the surface surrounded by the plurality of protruding electrodes is obtained, and the protruding portion provided on the lower plate is perpendicular to the center and the surface on which the protruding electrode of the semiconductor element is not formed. A method of leveling a protruding electrode of a semiconductor device, wherein the semiconductor device is placed so as to be in contact with an intersection or a position close to the intersection, and the height of the protruding electrode is leveled by applying the load in this state.