JP2004014778A - Semiconductor device and method of manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve conductivity between a bump electrode and an electrode located on a board in a face-down mounting manner wherein a mounting operation is carried out through an anisotropic conductive film. <P>SOLUTION: Two or more conical or trapezoidal protrusions 12a formed of passivation films 12 are previously formed on a wiring electrode 11 when the bump electrode 14 is formed. In this state, a bump underlying metal layer 13 is deposited, and furthermore a gold electrode is formed thereon through a deposition growth method so as to serve as the bump electrode 14. Irregularities are formed on the electrode surface of the bump electrode 14 corresponding to the irregularities provided on the wiring electrode 11, so that the plane of the electrode can be improved in flatness as a whole. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a semiconductor device and a manufacturing technology thereof, and is particularly effective when applied to a semiconductor device mounted by a flip chip method using bump electrodes.
[0002]
[Prior art]
The technology described below has been studied by the inventor when researching and completing the present invention, and the outline thereof is as follows.
[0003]
2. Description of the Related Art In semiconductor devices such as semiconductor chips, there is a strong demand for miniaturization, high-density mounting, and the like. In response to such technical demands, a so-called flip-chip mounting technique of aligning a semiconductor chip provided with bump electrodes on a mounting board side face down and connecting the bump electrodes and the mounting board side electrodes has been developed. Widely adopted.
[0004]
As the mounting using the flip-chip method, for example, mounting methods such as a chip-on-glass (COG) method, a chip-on-film (COF) method, and a chip-on-board (COB) method are known.
[0005]
In recent years, even in the field of liquid crystal technology in which higher definition and an increase in the number of pixels are required, for example, the above method is actively adopted as a mounting method of an LCD driver for controlling voltage switching related to liquid crystal display. .
[0006]
[Problems to be solved by the invention]
However, the present inventor has found that the above-described technology has the following problems.
[0007]
The flip-chip mounting is generally performed by interposing an anisotropic conductive film made of an anisotropic conductive resin or the like between a bump electrode on the semiconductor device side and an electrode on the mounting substrate. This is performed by heat-pressing the bump electrode to the mounting substrate side electrode.
[0008]
The electrical connection between the bump electrode and the mounting substrate-side electrode during such mounting is ensured by the conductive particles contained in the anisotropic conductive film being interposed between the bump electrode and the mounting substrate-side electrode. It will be.
[0009]
In other words, the conductive particles contained in the anisotropic conductive film are interposed between the bump electrode and the mounting substrate side electrode by the heat compression bonding so that the two electrodes can be electrically connected to each other. As a result, electrical connection is ensured along the route of the bump electrode, the conductive particles, and the mounting substrate side electrode.
[0010]
In order to secure electrical connection between the two electrodes by using the interposed conductive particles as intermediates, it is required to increase the density of the conductive particles between the two electrodes.
[0011]
However, during the mounting, if unevenness occurs in the pressure bonding of the bump electrode to the mounting board side electrode, the density of the conductive particles interposed between the two electrodes is relatively lower in the insufficiently pressed portion than in the normally pressed portion. It tends to be coarse.
[0012]
In such an underpressurized portion, the conductive particles interposed between the two electrodes are less compressed between the two electrodes as compared to the normal pressurized portion, and the conductive particles between the conductive particles, or between the electrode and the conductive particles, In some cases, the degree of contact is relatively weak, or a non-contact state occurs. In such a case, the electrical resistance at that portion increases, and good and sufficient conductivity between the two electrodes cannot be secured.
[0013]
For example, if a potential difference is applied between the two electrodes, a current certainly flows, but a sufficient current does not flow from the beginning, and an abnormality such as a long time is required until the voltage is sufficiently increased. Smooth switching of the voltage causes a serious obstacle to the clarity of the liquid crystal display in a liquid crystal display LCD driver that changes the liquid crystal state and performs the display.
[0014]
In addition, such an abnormality is caused in a completed product inspection of a semiconductor device such as a completed LCD driver or the like, when a test probe is applied to a predetermined position and its conduction is inspected, the reaction is slow or no conduction is shown. If the contact position is changed by slightly moving the probe, this may be one of the causes of a problem at the time of inspection such that conduction is suddenly confirmed.
[0015]
One of the major causes of such conduction abnormality is due to the surface shape of the bump electrode. A bump electrode is formed by removing a passivation film on a wiring electrode provided in a semiconductor device by etching or the like, and forming an electrode thereon by plating or the like.
[0016]
Therefore, in the bump electrode formed in this way, a depression is formed on the electrode surface that reflects the step between the passivation film surface and the wiring electrode surface when the passivation film is etched to expose the wiring electrode. Become.
[0017]
When a semiconductor device having a bump electrode having such a configuration is mounted face-down by a flip-chip method, the electrode surface having a dent faces the mounting substrate-side electrode, and the anisotropic conductive film interposed between the two electrodes. The pressing force on the conductive particles is slightly different between the concave portion and the peripheral portion that is not concave. That is, pressure unevenness occurs during mounting.
[0018]
Therefore, as a countermeasure, a means has been proposed to reduce the step between the passivation film surface and the wiring electrode surface by reducing the thickness of the passivation film. However, making the passivation film thinner, on the contrary, also lowers its insulating property, and a technique for securing the conductivity between the bump electrode and the electrode on the mounting board side without making the passivation film thinner. The development of is desired.
[0019]
An object of the present invention is to ensure sufficient conductivity between a bump electrode on a semiconductor device such as an LCD driver and a counter electrode such as a mounting board electrode connected to the bump electrode. is there.
[0020]
The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.
[0021]
[Means for Solving the Problems]
The following is a brief description of an outline of typical inventions disclosed in the present application.
[0022]
The present invention provides a plurality of recesses on the electrode surface of a bump electrode of a semiconductor device, the recesses being capable of conducting to a wiring electrode provided on the surface of the semiconductor device. By making the structure large, the conductivity between the bump electrode and the mounting substrate-side electrode can be satisfactorily ensured via the anisotropic conductive film containing the conductive particles.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In all the drawings for describing the embodiments, members having the same functions are denoted by the same reference numerals, and repeated description thereof will be omitted.
[0024]
FIG. 1A is a cross-sectional view schematically showing a bump electrode structure of a semiconductor device according to an embodiment of the present invention, and FIG. 1B is a sectional view showing a mounting substrate side using a bump electrode having the configuration shown in FIG. FIG. 4 is a cross-sectional view schematically showing a state where the device is mounted on the helmet.
[0025]
As shown in FIG. 1A, a wiring electrode 11 made of Al or the like is provided on the surface of the semiconductor device 10. A passivation film 12 is provided on the wiring electrode 11.
[0026]
On the wiring electrode 11, a passivation film 12 is provided intermittently in a convex shape corresponding to a portion where the bump electrode 14 is formed, and an uneven portion is formed. The convex portion 12a is formed in a conical section, and the concave portion 12b is formed in an inverted conical shape corresponding to the conical shape of the convex portion 12a. The bump electrode 14 made of Au or the like is provided on the uneven portion having the plurality of convex portions 12a and concave portions 12b with the bump base metal layer 13 interposed therebetween.
[0027]
On the electrode surface of the bump electrode 14 thus formed, a convex portion 14 a (14) and a concave portion 14 b (14) are respectively formed corresponding to the above-mentioned concave and convex portions formed of the passivation film 12 provided on the wiring electrode 11. A plurality is formed.
[0028]
Also, as shown in FIG. 1, the convex portion 12a and the concave portion 12b are formed in a conical or inverted conical shape, respectively, so that the convex portion 14a and the concave portion 14b of the bump electrode 14 are formed correspondingly. Are also formed in a conical shape and an inverted conical shape, respectively. In FIG. 1, for the sake of simplicity, the convex and concave portions 14 a and the concave portions 14 b on the electrode surface side of the bump electrode 14 are exaggerated from the convex portions 12 a and the concave portions 12 b.
[0029]
The pyramid means, for example, a cone or a pyramid such as a triangular pyramid, a quadrangular pyramid, or a pentagonal pyramid.
[0030]
When the bump electrode 14 is formed by plating growth, the convex and concave portions 14a and the concave portions 14b have smaller irregularities than those of the convex portions 12a and the concave portions 12b, and the concave and convex portions can be regarded as flat macroscopically. It has become.
[0031]
In the thus formed recess 14b, as shown in FIG. 1A, the recess opening side area S1 on the electrode surface side is the recess bottom surface area S2 (in the figure, the area of the bottom of the valley of the recess 14b is shown). ) Is formed larger.
[0032]
As shown in FIG. 1B, when the concave portion 14b is mounted on the electrode 16a on the mounting substrate 16 with the anisotropic conductive film 15 interposed therebetween, as shown in FIG. The conductive particles 17 may be set so as not to completely enter the recess 14b. That is, the width of the recess 14b may be set to be equal to or smaller than the average particle diameter of the conductive particles 17, for example.
[0033]
With this setting, as shown in FIG. 1B, the bump electrode 14 side of the semiconductor device 10 having the configuration shown in FIG. In the case of face-down mounting, the conductive particles 17 do not completely enter the recesses 14b, and the conductive particles 17 are reliably interposed between the bump electrodes 14 and the electrodes 16a of the mounting substrate 16, so that the bump electrodes 14 and the conductive particles 17, and the contact between the conductive particles 17 and the electrode 16 a can be ensured. Therefore, the conductivity between the bump electrode 14 and the electrode 16a on the mounting substrate 16 side is sufficiently ensured.
[0034]
In the above description, as shown in FIG. 1A, the shape of the convex portion 12a of the passivation film 12 provided on the wiring electrode 11 which determines the shape of the uneven portion formed on the electrode surface of the bump electrode 14 is formed in a conical shape. As described above, the concave portion 14b may have any shape as long as the concave portion opening side area S1 on the electrode surface side can be made larger than the concave portion bottom surface side area S2. For example, the convex portion 12a may be formed in a trapezoidal cross section.
[0035]
On the other hand, as shown in FIG. 2A, when the bump electrode 14 is provided on the wiring electrode 11 of the semiconductor device 10, unlike the case shown in FIG. In the case where the uneven portion composed of the convex portion 12a and the concave portion 12b is not provided, a large concave portion 19 reflecting the step portion 18 formed between the passivation film 12 and the wiring electrode 11 is provided on the electrode surface side. Will be formed.
[0036]
The recess 19 shown in FIG. 2A is much larger than the recess 14b shown in FIG. That is, in the configuration shown in FIG. 1A, a large depression corresponding to the large depression 19 is provided with a large number of depressions and projections composed of the small projections 14a and the depressions 14b, and one large depression is provided as a whole. In other words, it can be said that the electrode surface is quasi-planarly flattened.
[0037]
FIG. 2B shows a case where the bump electrodes 14 having such a configuration are mounted face-down with an anisotropic conductive film 15 interposed between the bump electrodes 14 and the electrodes 16a on the mounting substrate 16 side. In the portion corresponding to the concave portion 19, the concave portion 19 is originally formed in a large concave portion even when the pressure bonding is performed in the same manner as in FIG. In some cases, the conductive particles 17 in the anisotropic conductive film 15 cannot be interposed at high density. In the figure, as shown by the portion surrounded by the ellipse, the contact portion with the conductive particles 17 is reduced.
[0038]
FIG. 2B shows, as an example, a situation in which the concave portion 19 and the conductive particles 17 are separated from each other. That is, for example, as shown in FIG. 2B, the concave portion 19 occupying a large area of the electrode surface of the bump electrode 14 and the concave portion of the conductive particle 17 interposed between the concave portion 19 and the electrode 16a on the mounting substrate 16 side. 19. The contact with the electrode 16a is deteriorated. The pressing force of the conductive particles 17 tends to be weaker between the concave portion 19 and the electrode 16a than between the high peripheral portion 19a corresponding to the step 18 of the concave portion 19 and the electrode 16a.
[0039]
For this reason, there may be a case where the conductivity between the bump electrode 14 and the electrode 16a on the mounting board 16 side is not sufficiently ensured. Also, even if conductivity is ensured, as described above, for example, if a potential difference is applied between the two electrodes, a current certainly flows, but a sufficient current does not flow from the beginning, and it takes time until the voltage is sufficiently increased. And abnormalities such as
[0040]
Such a failure is an extremely fatal failure in an LCD driver of a liquid crystal display that changes the liquid crystal state and performs the display by smoothly switching the voltage, for example. It will not be possible to ensure sex and the like.
[0041]
However, the semiconductor device 10 according to the present invention having the bump electrodes 14 having the configuration shown in FIG. 1A is different from the semiconductor device 10 having the bump electrodes 14 having the configuration shown in FIG. Since the surface side is flattened, the conductive particles 17 can be interposed between the electrode 16a on the mounting substrate 16 side on average and the average conductivity can be sufficiently ensured.
[0042]
In addition, in the configuration shown in FIG. 1A, the apex of a large number of protrusions 14a intermittently provided on the surface side of the bump electrode 14 at intervals smaller than the average particle size of the conductive particles causes the apex macroscopically. Is regarded as a substantially continuous state and is pseudo-flattened. Therefore, it is necessary to reduce the thickness of the passivation film 12 to eliminate the step 18 proposed as a solution to the above problem. You don't have to do it. Forcibly reducing the thickness of the passivation film 12 may weaken the insulation based on the passivation film 12, but such danger can be avoided.
[0043]
Next, in the method of manufacturing the semiconductor device 10 having the bump electrode 14 having the above-described structure, as shown in FIG. 3, for example, an LCD driver 10a (10 ) Will be described as an example.
[0044]
FIG. 3 is a plan view showing an arrangement state of bump electrodes 14 of an LCD driver 10a formed in a slender rectangular shape for controlling voltage switching between a gate line group provided in a direction intersecting with the liquid crystal display mechanism and a drain line group. Indicated by As shown in FIG. 3, the LCD driver 10a is provided with a large number of bump electrodes 14 corresponding to a large number of gate lines and drain lines corresponding to the number of pixels of the liquid crystal display screen. A large number of bump electrodes 14 are provided along the long sides and short sides of the rectangular surface of the LCD driver 10a.
[0045]
The semiconductor device 10 included in the LCD driver 10a having the above configuration is provided with the bump electrodes 14 having the above-described structure by performing the steps shown in FIGS.
[0046]
In FIG. 4A, a drive circuit element for a liquid crystal display device and a wiring electrode 11 made of Al are formed on a wafer 31 at a position where a bump electrode 14 is formed by an existing method, and a passivation film 12 is formed thereon. The formed state is shown as a cross-sectional view of a main part.
[0047]
In the configuration shown in FIG. 4A, a resist 32 is applied on the passivation film 12. A mask pattern is exposed by stepper exposure in a range corresponding to the wiring electrode 11 of the applied resist 32, and the mask pattern is patterned on the resist 32 by development after exposure. FIG. 4B is a sectional view showing a state where the resist 32 is patterned.
[0048]
Various patterns can be considered for the pattern formed on the resist 32. For example, as shown in FIG. 42, 43, and 44 may be provided.
[0049]
Alternatively, as shown in FIG. 5B, the recesses 45 formed in a substantially rectangular shape may be arranged in a matrix. Further, as shown in FIG. 5C, the concave portions 46 formed in a rectangular shape may be provided in a row. Further, as shown in FIG. 5D, the recess 47 may be formed in an annular shape. A plurality of such concave portions 47 formed in an annular shape may be provided concentrically.
[0050]
As shown in FIG. 4C, the passivation film 12 is patterned by etching with an enhanced isotropic property using the resist 32 that has been subjected to predetermined patterning as a mask.
[0051]
As such etching, for example, isotropic dry etching can be used. Usually, in the isotropic dry etching, the pressure is set to 0.1 to 1.0 Torr (1.3332 × 10 to 1.333322 × 10 3 Torr). ² Pa) and the gas type is CF ₄ And 8% O ₂ In general, the etching is performed by using an etching condition in which isotropic etching is performed. However, in the present embodiment, an etching condition in which the isotropic property is further strengthened is adopted unlike the ordinary isotropic etching condition.
[0052]
That is, under the above pressure, CF ₄ And O ₂ Was added to increase the isotropy. As the gas type, SF ₆ May be used.
[0053]
In this way, the passivation film 12 is patterned by dry etching with enhanced isotropy, and then the resist 32 used as a mask is removed. FIG. 4D is a sectional view showing a state in which the resist 32 has been removed in this manner.
[0054]
As shown in FIG. 4D, on the wiring electrode 11, a plurality of convex portions 12a formed of a passivation film 12 and having a conical cross section are intermittently left, and a concave portion 12b is also formed. That is, the uneven portion is provided on the wiring electrode 11.
[0055]
With the uneven portions provided on the wiring electrodes 11 in this way, as shown in FIG. 6A, a bump underlayer metal layer 13 is deposited to a predetermined thickness. For example, a Cr layer, a Cu layer, and an Au layer may be sequentially deposited and stacked from the lower layer by sputtering.
[0056]
After the bump base metal layer 13 is deposited to a predetermined thickness in this way, a resist 33 is applied to the predetermined thickness. After the application of the resist, the mask pattern is exposed by stepper exposure corresponding to the wiring electrode 11, and a mask pattern for forming a bump electrode is patterned on the resist 33 by development after the exposure. FIG. 6B is a sectional view showing such a state.
[0057]
Thereafter, using the patterned resist 33, as shown in FIG. 6C, the Au bump electrode 14 is formed by electrolytic plating. After the formation of the bump electrode 14, as shown in FIG. 7A, the resist 33 for forming the bump electrode is removed. Further, an unnecessary portion of the bump base metal layer 13 is removed, and as shown in FIG. 7B, an LCD driver 10a as the semiconductor device 10 having the bump electrodes 14 of the configuration according to the present invention is manufactured.
[0058]
As shown in FIG. 7B, the bump electrode 14 formed by the above-described series of steps is formed by forming a plurality of protrusions 12a of the passivation film 12 on the wiring electrode 11 intermittently, thereby forming an uneven portion. The state reflecting the irregularities thus formed is formed as the irregularities composed of the projections 14a and the depressions 14b on the electrode surface of the bump electrode 14.
[0059]
The uneven portion formed on the electrode surface of the bump electrode 14 is formed by growing gold plating in the vertical direction from the state of FIG. 6B, and the growth of the gold plating grows not only in the vertical direction but also in the horizontal direction. Therefore, the plating growth in the vertical direction and the horizontal direction is combined, and the uneven portion on the electrode surface has a gentle uneven shape in which the height of the unevenness is lower than the uneven portion formed by the passivation film 12 on the wiring electrode 11. ing.
[0060]
In particular, when the bump electrode 14 is formed, as shown in FIG. 4D, in the uneven portion formed on the wiring electrode 11, the concave portion 12b formed in accordance with the convex portion 12a of the passivation film 12 has a passivation. The opening area S3 on the front surface side of the film 12 is formed in a hole portion larger than the opening area S4 on the wiring electrode 11 side.
[0061]
For this reason, since the side surface of the convex portion 12a is formed in a tapered shape as compared with a case where such a hole portion is formed, for example, in a straight shape in which the side surface of the convex portion is stood vertically, that is, in a columnar shape, the bump base by sputtering is formed. The deposition of the metal layer 13 can be performed evenly in the recess 12b.
[0062]
Further, as described above, in the case of the uneven portion formed by the convex portion having the side surface extending straight, the opening area S3 on the front surface side of the passivation film 12 and the opening area on the wiring electrode 11 side are formed. A columnar hole having substantially the same size as the area S4 is formed. When the under bump metal layer 13 is deposited in this state, the opening area S3 becomes small, and in the subsequent gold plating for forming the bump electrode 14, the plating solution hardly penetrates to the bottom of the hole. There is a high possibility that a state in which the void is confined on the bottom side will occur.
[0063]
However, in the present invention, since the opening area S3 is formed to be larger than the opening area S4, the plating solution can flow smoothly, and the generation of a void which becomes a resistance at the time of conduction can be prevented. Therefore, the reliability of the formed bump electrode 14 in terms of conductivity can be improved.
[0064]
Further, as shown in FIG. 4D, the concave portion 12b is formed in a substantially inverted trapezoidal cross section, and further, a bump base metal layer 13 is deposited in a subsequent step, so that the convex portion 13a and the concave portion 13b As a result, an uneven portion is formed. The recess 13b after the deposition of the bump base metal layer 13 is in a state in which the recess space is more filled than the recess 12b by plating.
[0065]
As described above, when the concave space is formed in a concave and convex shape such as a rectangular waveform by the convex portion having the side surface extending directly upward, as described above, the opening area S3 on the front surface side of the passivation film 12 and the wiring area 11 side Since the opening area S4 is formed in a columnar hole having substantially the same size as the opening area S4, for example, when the opening area S3 is assumed to be the same, the recessed space shown in FIG. It can be said that the recess is easily buried by the subsequent gold plating.
[0066]
That is, in the configuration according to the present invention, in which the recess 13b is easily embedded by plating growth, the electrode of the bump electrode 14 is formed in an uneven shape such as a rectangular waveform by the convex portion having the side surface extending upward. It can be said that the surface is easier to flatten.
[0067]
As described above, according to the present invention, when the bump electrode 14 is formed, the opening area S3 on the surface side of the passivation film 12 on the passivation film 12 on the wiring electrode 11 is larger than the opening area S4 on the wiring electrode side. In addition, by forming a plurality of holes communicating with the wiring electrode 11, the surface of the bump electrode formed by the subsequent plating growth is further flattened.
[0068]
If the LCD driver 10a (10) having the bump electrode 14 whose flattening is promoted is used, as shown in FIG. 8, a liquid crystal corresponding to the bump electrode 14 of the LCD driver 10a and the electrode 16a of the mounting board 16 is used. Conductivity in flip-chip mounting in which the anisotropic conductive film 15 is interposed between the substrate 51 and the liquid crystal side wiring layer 51a can be sufficiently ensured.
[0069]
As schematically shown in FIG. 8, the width of the concave portion 14 b of the uneven portion formed on the electrode surface of the bump electrode 14 is formed smaller than the average particle size of the conductive particles 17, and as described above, the flatness is high. Is set. Therefore, unlike the bump electrode structure having the structure shown in FIG. 2B, the bump electrode structure having the structure shown in FIG. 8 has a larger distance between the bump electrode structure and the liquid crystal side wiring layer 51a over the entire surface of the electrode surface. The conductive particles 17 included in the anisotropic conductive film 15 to be interposed can be sandwiched so as to be crushed by being interposed at high density on average.
[0070]
Therefore, a conduction route including the bump electrode 14, the conductive particles 17, and the liquid crystal side wiring layer 51 a can be reliably established, and the conduction can be sufficiently ensured.
[0071]
FIGS. 9A and 9B show a case where the shape of the projection 12a of the passivation film 12 to be left on the wiring electrode 11 is set to a trapezoidal cross section in steps corresponding to FIGS. 4C and 4D. Of the bump electrode 14 in FIG. A portion formed corresponding to the upper bottom portion of the convex portion 12a having a trapezoidal cross section is indicated by a convex portion 14a in the figure. FIGS. 9A and 9B show a case where the concave portion 14b is formed concentrically.
[0072]
FIG. 9A shows the case where the bump electrode 14 is formed concentrically according to the shape of the rectangular bump electrode 14, and FIG. 9B shows the case where it is formed concentrically according to the shape of the square bump electrode 14. By forming the concentric shape, the conductive area of the concave portion 14b on the wiring electrode 11 can be made larger than in the case where the conductive area is formed in a row.
[0073]
Of course, the arrangement of the concave portions 14b may be formed in a matrix or a row as shown in FIG. Further, in the above description, the case where the concave portion is formed in a plane linear shape is shown, but the concave portion may be formed so as to meander in a waveform to increase the conductive area.
[0074]
As described above, the invention made by the inventor has been specifically described based on the embodiment. However, the present invention is not limited to the embodiment, and various modifications can be made without departing from the gist of the invention. Needless to say.
[0075]
For example, in the above description, the LCD driver is described as an example. However, the present invention is not limited to the LCD driver, and the bump electrode may be mounted face-down by face-down mounting with an anisotropic conductive film interposed therebetween. It is needless to say that the present invention can be applied to a semiconductor device having a structure of being electrically connected to an electrode.
[0076]
【The invention's effect】
The effects obtained by typical aspects of the invention disclosed in the present application will be briefly described as follows.
[0077]
That is, the flatness of the surface of the bump electrode can be increased, and the conductivity between the bump electrode and the partner electrode can be improved.
[Brief description of the drawings]
FIG. 1A is a cross-sectional view schematically showing a bump electrode structure of a semiconductor device according to an embodiment of the present invention, and FIG. 1B is mounted using a bump electrode having the configuration shown in FIG. It is sectional drawing which shows the state mounted on the board side typically.
FIG. 2A is a cross-sectional view schematically showing a bump electrode structure formed without providing an uneven portion on a wiring electrode, unlike the configuration shown in FIG. 1, and FIG. FIG. 4 is a cross-sectional view showing a state where the bump electrode having the configuration shown in FIG.
FIG. 3 is a plan view showing the arrangement of bump electrodes in a semiconductor device configured as an LCD driver.
FIGS. 4A to 4D are cross-sectional views illustrating a series of example steps of a method of manufacturing a semiconductor device according to an embodiment of the present invention.
FIGS. 5A to 5D are plan views showing examples of patterning a passivation film.
FIGS. 6A to 6C are cross-sectional views illustrating a series of example steps of a method of manufacturing a semiconductor device according to an embodiment of the present invention.
FIGS. 7A and 7B are cross-sectional views showing a state in which a bump electrode is formed by a series of steps of a method of manufacturing a semiconductor device according to the present invention.
FIG. 8 is a cross-sectional view of an essential part showing an example of a state in which an LCD driver of a semiconductor device provided with bump electrodes having a configuration according to the present invention is mounted on a liquid crystal substrate side.
FIGS. 9A and 9B are plan views illustrating a case where concave portions on the surface of a bump electrode are formed concentrically.
[Explanation of symbols]
10 Semiconductor device
10a LCD driver
11 Wiring electrode
12 Passivation film
12a convex part
12b recess
13 Under bump metal layer
13a convex
13b recess
14 Bump electrode
14a recess
14b convex part
15 Anisotropic conductive film
16 Mounting board
16a electrode
17 conductive particles
18 steps
19 recess
19a Peripheral part
31 wafer
32 resist
33 Resist
41 recess
42 recess
43 recess
44 recess
45 recess
46 recess
51 LCD substrate
51a Liquid crystal side wiring layer
S1 recess opening side area
S2 Concave bottom surface area
S3 opening area
S4 opening area

Claims (5)

A semiconductor device having a bump electrode,
On the electrode surface of the bump electrode, a plurality of recesses that are electrically connected to a wiring electrode provided on the semiconductor device are provided,
The semiconductor device is characterized in that the recess has an area on the electrode opening side on the electrode surface side larger than the area on the recess bottom side. A semiconductor device having a bump electrode,
On the electrode surface of the bump electrode, a plurality of recesses that are electrically connected to wiring electrodes provided on the semiconductor device are provided concentrically,
The semiconductor device is characterized in that the recess has an area on the electrode opening side on the electrode surface side larger than the area on the recess bottom side. A semiconductor device having a bump electrode that is conductively connected to an electrode on a mounting substrate side via an anisotropic conductive film containing conductive particles,
An uneven portion is provided on the electrode surface of the bump electrode,
The concave portion of the concave and convex portion is electrically connected to a wiring electrode provided on the semiconductor device, and the concave portion opening side area on the electrode surface side of the concave portion is formed to be larger than the concave portion bottom surface side area,
The semiconductor device according to claim 1, wherein a dimension of the concave portion on the electrode surface side is set smaller than an average particle size of the conductive particles. A method of manufacturing a semiconductor device having a bump electrode,
A step of providing a hole communicating with the wiring electrode so that an opening area on the surface of the passivation film is larger than an opening area on the wiring electrode side in the passivation film provided on the wiring electrode of the semiconductor device;
Forming a bump electrode on the wiring electrode so as to be conductive to the wiring electrode through the hole. A method of manufacturing a semiconductor device having a bump electrode,
A step of subjecting the passivation film provided on the wiring electrode of the semiconductor device to an isotropic etching treatment so as to intermittently leave a passivation film having a conical or trapezoidal cross section on the wiring electrode;
A step of providing a bump base metal layer on the wiring electrode while the passivation film having a conical or trapezoidal cross section is intermittently left on the wiring electrode;
Forming a bump electrode by plating on the bump base metal layer.

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