JP4089531B2 - Manufacturing method of semiconductor device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing a semiconductor device and a semiconductor device manufactured by the method, and in particular, in the manufacture of a semiconductor device in which a semiconductor element is bonded to a wiring board via a so-called metal bump, the density of metal bumps is high. The present invention relates to a method that makes it possible.
[0002]
[Prior art]
There is an ever-increasing demand for high-density mounting of electronic components, and the bare chip method is regarded as important as a method of mounting a semiconductor element on a wiring board. From the viewpoint of the electrical external connection structure in the bare chip mounting method, the face up mounting using the wire bonding method is changing to the face down mounting by flip chip bonding using solder bumps.
[0003]
In flip chip bonding using solder bumps, solder bumps are formed on the electrodes on the surface of the semiconductor element. As the solder bump forming method, there is the following method.
B) After depositing a desired metal by a vapor deposition method on a dummy wafer through a metal mask so as to have a target circuit pattern, the desired metal is aligned and transferred to the wafer on which the semiconductor element chip is formed. After applying the flux, it is wet-backed (melted and made liquid).
B) A resist mask is formed on the wafer on which the semiconductor element chip is formed, and a solder metal layer having a desired composition and film thickness is formed by electrolytic plating on the electrode exposed in the opening of the mask. After applying, wet back.
C) A mask made of a heat-resistant insulating film having an opening for exposing an electrode is formed on a wafer on which a semiconductor element chip is formed, and a solder paste mixed with a flux component is put into the mask opening with a squeegee or the like. After filling, it is heated and melted, and after further removing the insulating film, it is wet-backed. (For example, see Patent Document 1)
[0004]
[Patent Document 1]
JP 2000-277552 A (page 3-4, FIG. 1)
[0005]
[Problems to be solved by the invention]
Conventionally, solder bumps with an array pitch of several hundreds of μm (for example, 200 μm) have been formed by using any of the above methods, but the array pitch tends to further decrease in the future. There is a growing demand for 100 μm or less, for example, 50 μm. Along with this, the bump diameter is also reduced.
[0006]
When the bump diameter is 50 μm or less, the solder bump after a normal wet-back becomes a spherical shape. This example will be described with reference to FIG.
As shown in FIG. 1A, for example, a photosensitive dry film 40 is attached to the surface of the semiconductor element 10 on which the pad electrode 14 is formed, as shown in FIG. As shown in c), exposure is performed using the glass mask 100, and as shown in FIG. 1 (d), a resist mask 42 having an opening for exposing the pad electrode 14 is formed. In addition, the code | symbol 12 is SiO, for example ₂ An insulating film made of Next, as shown in FIG. 1E, a solder layer 16 ′ is formed on the pad electrode 14 by, for example, electrolytic plating, and then wet-backed. As a result, the solder layer becomes a spherical solder bump 16 as shown in FIG. Next, the resist mask 42 is removed to obtain the semiconductor element 10 having the structure shown in FIG.
[0007]
When such a solder bump becomes spherical with a diameter of about 50 μm or less, the measurement error of the sphere recognition degree becomes large. As a result, the measurement error of the bump height is increased, and the alignment accuracy is lowered. As a result, it is easy to cause a bonding failure due to a positional deviation or the like.
In addition, when the bump height is reduced, the ability to relieve the strain caused by the difference in thermal expansion coefficient between the semiconductor element and the wiring board joined via the bump is lowered, and the joint in a long-time temperature cycle test is reduced. Concerns arise about the assurance of reliability. This means that the conventional wetback method in which the solder bumps have a spherical shape is not preferable as the bumps are reduced.
[0008]
In addition, the solder bump forming method of item (c) is effective from the viewpoint of cost reduction. However, when the solder bump array pitch becomes finer than 50μm, the particle size distribution and shape variation of the solder metal powder will cause the volume variation between the bumps. There is a problem that the reliability of the joining is reduced.
[0009]
Further, as another problem to be considered along with high-density mounting of electronic components, there is the adoption of a low-k (that is, low dielectric constant) film. For high-density mounting of electronic components, it is essential to narrow the pitch of the electrodes and increase the number of wiring layers. For this purpose, a low-k insulating film is used as an interlayer insulating film. At present, porous organic or inorganic films have been proposed as low-k insulating films. Such a porous interlayer insulating film has low mechanical strength, and if an ultrasonic bonder load is applied to the electrode formed thereon, for example, during stack wire bonding, the interlayer insulating film may be crushed and damaged. is there. Accordingly, when bump bonding a semiconductor element using such an interlayer insulating film to a wiring board, it is necessary to be able to bond it by applying as little load as possible.
[0010]
In flip chip mounting, the thermal expansion characteristic is adjusted in the gap between the semiconductor element and the wiring board in order to relieve stress caused by the difference in thermal expansion characteristic between the semiconductor element and the wiring board on which the semiconductor element is mounted. Filling (under-filling) resin is performed. In this case, before the semiconductor element is bump-bonded to the wiring board, for example, an underfill resin is supplied to the surface of the wiring board on which the counter electrode is formed, and then the semiconductor element is bump-bonded, for example. .
[0011]
For example, as shown in FIG. 2A, a fluid resin layer 6 is applied to the surface of the wiring board 5 on which the electrodes 4b are formed. On the other hand, the semiconductor chip 1 on which the bump 4a is formed is arranged, and as shown in FIG. 2B, the bump 4a enters the resin layer 6 and contacts the electrode 4b. The wiring board 5 is brought close and heated to melt-bond the bumps 4a and the electrodes 4b, and to cause the resin layer 6 to undergo a crosslinking reaction and to be cured.
[0012]
This method is more difficult to fill the underfill resin in a state where the semiconductor element and the wiring board are bonded, as the gap between the semiconductor element and the wiring board becomes narrower, the number of bumps increases, and the arrangement pitch becomes denser. This is an effective way to solve this problem. However, the resin layer 6 is dispersed and mixed with filler 8 made of organic or inorganic particles for adjusting the coefficient of thermal expansion after curing. As a result, the filler 8 is interposed between the bump 4a and the electrode 4b, and the bonding and electrical connection between them are impaired. This problem is more susceptible to finer bumps.
[0013]
[Means for Solving the Problems]
An object of the present invention is to provide a technique for comprehensively solving the above-described problems, and in particular, to provide a method capable of bonding a semiconductor element and a wiring board with a force that does not damage a low-k insulating film. For the purpose. It is another object of the present invention to provide a method capable of ensuring electrical connection between a bump-bonded semiconductor element and a wiring board regardless of the filler in the underfill resin. Another object of the present invention is to provide an effective method for reducing the heating temperature in the step of face-down bonding the semiconductor element to the wiring board and for suppressing the temperature rise of the wiring board having a larger thermal expansion coefficient than that of the semiconductor element. And
[0014]
An object of the present invention is to provide a method of manufacturing a semiconductor device in which an electrode of a semiconductor element and an electrode of a wiring board are connected, a step of forming an insulating film having an opening on the electrode of the wiring board, and a metal layer in the opening Forming a first metal bump by melting the metal layer by heating and solidifying the metal layer, then removing the insulating film, and forming an opening on the electrode of the semiconductor element. A step of forming an insulating film, a step of forming a metal layer in the opening, a second metal bump having a height lower than that of the first metal bump by solidifying after melting the metal layer by heating. A step of forming, a step of subsequently removing the insulating film, a step of thermocompression bonding after aligning the first metal bump and the second metal bump, A step of filling a thermosetting adhesive having a flux action between the thermocompression-bonded wiring board and the semiconductor element; and curing the thermosetting adhesive by heating; and the first metal bump Electrically connecting the electrode of the wiring board and the electrode of the semiconductor element with the second metal bump; It is solved by the manufacturing method of the semiconductor device characterized by including.
[0015]
The above will be described in some detail. First, in the present invention, the solder bump is heated to a temperature lower by about 10 ° C. to 20 ° C. than its melting point in a state where it is in contact with the counter electrode. At this temperature, the Young's modulus of the solder bump is significantly lower than the value at room temperature. For example, in the case of a tin-bismuth alloy solder having a melting point of 138 ° C., the Young's modulus at 128 ° C. is about 1/3 at room temperature. As a result, the solder bump can be thermocompression bonded to the counter electrode with a low load.
[0016]
Even in this state, a certain degree of mechanical strength and electrical connection is obtained, but between the semiconductor element and the wiring board, a thermosetting underfill resin is filled, and the whole is higher than the melting point of the solder bump. For example, it is heated to a temperature 30 ° C. higher. As a result, the solder bump is melted to achieve sufficient electrical and mechanical joining with the counter electrode, and the under-fill resin is cured to obtain sufficient reinforcing strength.
[0017]
According to the present invention, the metal bump is formed in a columnar shape by performing wet-back of the solder layer before removing the resist mask used for forming the solder layer on the pad electrode of the semiconductor element to form the metal bump. Is done. Therefore, the height of the metal bump is about twice as high as when the wet bump is performed after removing the resist mask and the metal bump becomes spherical. As a result, it is possible to use metal bumps having a fine pitch and a large aspect ratio.
[0018]
In addition, a metal bump is thermocompression bonded to the counter electrode with a low load. This, combined with the fact that the aspect ratio of the metal bump can be increased, makes it possible to avoid damage to the low-k insulating film due to the pressing force during thermocompression bonding.
The underfill resin is filled in a state where the metal bumps are columnar and have a large aspect ratio, and the metal bumps are temporarily bonded to the counter electrode by thermocompression bonding. As a result, filling can be performed quickly and easily, and the filler mixed with the underfill resin does not affect the electrical and mechanical bonding between the metal bump and the counter electrode, and the thermal and other properties of the underfill resin. There is an advantage that can be easily adjusted.
[0019]
In the present invention, a metal bump having a high height is formed on a wiring board on which a semiconductor element is mounted, and a metal bump having a lower height is formed on the semiconductor element, or only a pad electrode is used as a counter electrode. Including doing. As a result, the heat conduction path in the thermocompression bonding between the counter electrode of the semiconductor element and the metal bump of the wiring board is shorter on the semiconductor substrate side than the bonding surface of the counter electrode and the metal bump, and on the wiring board side. long.
[0020]
Normally, heating is performed from the semiconductor element side by a bonding tool. By setting the height of the metal bumps to the above relationship, the temperature drop at the metal pad on the semiconductor element side is small, and the wiring board side is heated. The temperature drop at the metal pad is greater. As a result, the set temperature of the bonding tool for heating the bonding surface to a predetermined temperature can be lowered. Further, the temperature rise of the wiring board is reduced, and the generation of thermal stress due to the thermal expansion of the wiring board can be suppressed. As a result, the reliability of bonding can be improved.
[0021]
In the present invention, a solder bump made of at least one of tin, silver, bismuth, indium, copper, antimony, gold, and zinc is used as the metal bump. In particular, by using solder bumps containing indium and at least one of tin, silver, bismuth and zinc as the second component as metal bumps on semiconductor elements, the bonding temperature and the Young's modulus of the solder bumps at the bonding temperature are reduced. Therefore, it is possible to realize the joining under a low load and improve the joining reliability.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
A method of manufacturing a semiconductor device according to the first embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 3A, for example, a photosensitive dry film 40 is attached to the surface of the semiconductor element 30 on which the pad electrode 34 is formed, as shown in FIG. As shown in FIG. 2, ultraviolet rays are irradiated through the glass mask 100 to expose a predetermined pattern on the photosensitive dry film 40. This is developed to form a resist mask 42 having an opening for exposing the pad electrode 34 as shown in FIG. In addition, the code | symbol 32 is SiO, for example ₂ An insulating film made of
[0023]
Next, as shown in FIG. 3E, a solder layer 36 ′ is formed on the pad electrode 34 exposed in the opening of the resist mask 42. The solder layer 36 'can be formed by using an electrolytic plating method or a vapor deposition method, but the former is more advantageous in terms of cost. In FIG. 3 (e), the solder layer 36 ′ is formed to a thickness higher than that of the resist mask 42. Although it is not essential to set the thickness of the solder layer 36 ′ in this way, as described above, it is caused by a difference in thermal expansion coefficient between the semiconductor element 30 and a wiring board (not shown) on which the semiconductor element 30 is mounted. In order to relieve stress, it is desirable to form a metal bump as high as possible. However, if an attempt is made to make it too high, the solder layer 36 ′ spreads laterally on the resist mask 42 and a so-called bridge is formed with the adjacent solder layer 36 ′. Therefore, it goes without saying that the thickness immediately before forming the bridge is the limit.
[0024]
The metal component constituting the solder layer 36 ′ is selected from at least one of tin, silver, bismuth, indium, copper, antimony, gold, and zinc. The metal component constituting the solder layer 36 ′ may be selected so that indium is included as an essential component and at least one of tin, silver, bismuth, and zinc is included as a second component. Thereby, the heating temperature and the pressing force in the thermocompression bonding process to be described later can be set lower.
[0025]
Next, with the resist mask 42 left, the solder layer 36 'is heated to a temperature equal to or higher than its melting point and melted (wet back). As a result, the top of each solder layer 36 ′ becomes flat as shown in FIG. 3 (f) due to surface tension when melted.
Next, after cooling to below the melting point and solidifying, the resist mask 42 is removed. As a result, as shown in FIG. 3G, free-standing bumps 36 having a desired height arranged at a predetermined pitch are obtained.
[0026]
Next, the semiconductor element 30 on which the solder bumps 36 are formed as described above is disposed so as to face the counter electrode (not shown) formed on the wiring board 50 as shown in FIG. The counter electrode in the wiring board 50 may be a pad electrode made of, for example, copper foil, or may be a bump electrode formed on such a pad electrode. However, in the case of a bump electrode, it is desirable to have a melting point higher than that of the solder bump 36 formed on the semiconductor element 30.
[0027]
Next, as shown in FIG. 4 (i), the solder bump 36 of the semiconductor element 30 is in contact with the counter electrode (not shown) of the wiring substrate 50, or at least the solder bump 36 is melted by the melting point of the solder bump 36. The solder bump 36 is thermocompression bonded to the counter electrode by heating to a temperature lower by about 10 ° C. to 20 ° C. and applying a load that does not cause deformation of the solder bump 36.
[0028]
Next, as shown in FIG. 4 (j), an underfill resin 60 is inserted between the semiconductor element 30 and the wiring board 50 at, for example, a well-known potting at a heating temperature during the thermocompression bonding or below, for example, room temperature. Then, the whole is heated to the melting point of the solder bump 36 or, for example, about 30 ° C. higher than that. As a result, the solder bump 36 is melted to be in a sufficiently joined state with the counter electrode, and the underfill resin 60 is cured.
[0029]
Thereafter, the whole is cooled to room temperature. During this time, each solder bump 36 melts and solidifies in a state of being confined in the under-fill resin 60, so that there is no possibility that the solder bump is deformed or a bridge between adjacent ones is formed.
In the first embodiment, the columnar solder bumps 36 are formed on the semiconductor element 30 and the solder bumps 36 are joined to the counter electrode (not shown) of the wiring board 50. A second embodiment in which bumps are formed and bonded to the counter electrode of the semiconductor element will be described next.
[0030]
As shown in FIG. 5A, for example, a photosensitive dry film 40 is attached to the surface of the wiring board 50 on which the pad electrode 54 is formed, as shown in FIG. 5B, for example. As shown in FIG. 2, ultraviolet rays are irradiated through the glass mask 100 to expose a predetermined pattern on the photosensitive dry film 40. This is developed to form a resist mask 42 having an opening for exposing the pad electrode 54 as shown in FIG. Reference numeral 52 is, for example, SiO. ₂ An insulating film made of
[0031]
Next, as shown in FIG. 5 (e), a solder layer 56 ′ is formed on the pad electrode 54 exposed in the opening of the resist mask 42. The solder layer 56 ′ can be formed by using an electrolytic plating method or a vapor deposition method. As shown in FIG. 5E, the solder layer 56 ′ is preferably formed to a thickness higher than that of the resist mask. However, the thickness of the solder layer 56 ′ on the resist mask 42 is such that it does not form a bridge as described above. The metal component constituting the solder layer 56 ′ in the second embodiment is selected to be at least one of tin, silver, bismuth, indium, copper, antimony, gold, and zinc.
[0032]
Next, with the resist mask 42 remaining, the solder layer 56 ′ is heated to a temperature equal to or higher than its melting point and melted (wet back). As a result, each solder layer 56 ′ has a columnar shape with a flat top as shown in FIG. 5 (f) due to surface tension when melted.
Next, as shown in FIG. 5G, after cooling to a melting point or lower and solidifying, the resist mask 42 is removed. As a result, free-standing bumps 56 having a desired height arranged at a predetermined pitch are obtained.
[0033]
On the other hand, as shown in FIG. 6 (h), for example, a photosensitive dry film 40 is attached to the surface of the semiconductor element 30 on which the pad electrode 34 is formed, as shown in FIG. As shown in j), ultraviolet rays are irradiated through the glass mask 100 to expose a predetermined pattern on the photosensitive dry film 40. This is developed to form a resist mask 42 having an opening for exposing the pad electrode 34, as shown in FIG. 6 (k). In this case, the thickness of the photosensitive dry film 40 may be the same as that in the process described with reference to FIG. Reference numeral 32 denotes, for example, SiO. ₂ An insulating film made of
[0034]
Next, as shown in FIG. 6L, a solder layer 36 ′ having a predetermined height is formed on the pad electrode 34 exposed in the opening of the resist mask 42. In FIG. 1 (l), the solder layer 36 'is formed with a height lower than the thickness of the resist mask 42. However, even if a photosensitive dry film 40 having the same thickness as the solder layer 36' is used. There is no problem. The solder layer 36 ′ needs to be formed at a height lower than the height of the solder bump 56 formed on the wiring board 50 by the process described with reference to FIG. 5.
[0035]
The metal component constituting the solder layer 36 ′ can be selected from at least one of tin, silver, bismuth, indium, copper, antimony, gold, and zinc, but contains indium as an essential component. It is desirable to select at least one of tin, silver, bismuth and zinc as the second component. This is because the melting point of the solder bump formed on the semiconductor element 30 is lower than the melting point of the solder bump 56 formed on the wiring substrate 50 described with reference to FIG. This is because it is desirable in terms of the set value and distribution of the pressing force.
[0036]
Next, with the resist mask 42 left, the solder layer 36 'is heated to a temperature equal to or higher than its melting point and melted (wet back).
Next, after cooling to below the melting point and solidifying, the resist mask 42 is removed. As a result, as shown in FIG. 6 (m), self-supporting bumps 36 having a desired height arranged at a predetermined pitch are obtained.
[0037]
Next, referring to FIG. 7, the semiconductor element 30 on which the solder bumps 36 are formed as described above is disposed so as to face the solder bumps 56 formed on the wiring board 50, as shown in FIG. 7 (n). .
Next, as shown in FIG. 7 (o), with the solder bumps 36 of the semiconductor element 30 in contact with the solder bumps 56 of the wiring substrate 50, the bonding tool 70 is brought into contact with and pressed against the back surface of the semiconductor element 30. . Thus, at least the solder bump 36 is heated to a temperature lower by about 10 ° C. to 20 ° C. than the melting point of the solder bump 36 and a load that does not cause deformation of the solder bump 36 is applied. And thermocompression bonding.
[0038]
Next, as shown in FIG. 7 (p), an underfill resin 60 is inserted between the semiconductor element 30 and the wiring board 50 at, for example, a known potting at a heating temperature during the thermocompression bonding or below, for example, room temperature. Then, the whole is heated to the melting point of the solder bump 36 or, for example, about 30 ° C. higher than that. As a result, at least the solder bumps 36 are melted and are in a sufficiently joined state with the solder bumps 56. At the same time, the under-fill resin 60 is cured. Thereafter, the whole is cooled to room temperature. During this time, each solder bump 36 melts and solidifies in a state of being confined in the under-fill resin 60, so that there is no possibility that the solder bump is deformed or a bridge is formed between adjacent solder bumps.
[0039]
As described above, by selecting the composition of the solder layer 36 'so that indium is an essential component and at least one of tin, silver, bismuth, and zinc is included as a second component as described above, solder bumps can be obtained. The Young's modulus at the melting point of 36 and the heating temperature at the time of thermocompression bonding can be made lower than those of the solder bumps 56 formed on the wiring board 50. As a result, the heating temperature and the pressing force in the thermocompression bonding process can be set lower. Furthermore, even if there is non-uniformity in the distribution of the heating temperature, pressing force and solder bump 56 height in the substrate surface applied during thermocompression bonding, the effect of absorbing the influence due to deformation of the solder bump 36 is obtained. is there.
[0040]
FIG. 8 shows the difference between the first embodiment in which metal bumps are formed on the semiconductor element as described above and the second embodiment in which metal bumps having a height higher than the counter electrode on the semiconductor element are formed on the wiring board. The description will be given with reference.
8A and 8B show the case of the first embodiment in which the metal bumps 36 are formed on the semiconductor element 30. FIG.
[0041]
FIG. 8C shows the case of the second embodiment in which the metal bump 56 having a high height is formed on the wiring substrate 50 and the metal bump 36 having a low height is formed on the semiconductor element 30.
The distance L between the metal bumps 36 in the heat conduction path passing through the metal bumps 36 in FIG. ₁ And distance L of the metal bump 36 portion in the heat conduction path passing through the metal bump 36 in FIG. ₂ And L ₁ Is L ₂ It is longer and the temperature drop in the metal bump 36 in FIG. 8A is larger than that in the metal bump 36 in FIG. That is, in the latter case, a temperature close to the temperature of the bonding tool 70 is applied to the joint surface between the metal bump 36 and the metal bump 56. If the temperature of the bonding surface is constant, the latter means that the temperature of the bonding tool 70 can be set lower. Further, since the latter has a larger distance from the bonding surface to the wiring substrate 50, the temperature rise of the wiring substrate 50 due to heating during the thermocompression bonding of the metal bumps is reduced, and the influence of the difference in thermal expansion characteristics from the semiconductor element 30 is exerted. And the reliability of bonding can be improved.
[0042]
Specific examples of the present invention will be described below. The present invention is not limited to the following examples.
Items common to the following embodiments are listed in advance.
B) Raw materials for metal bumps
Tin, silver, bismuth, copper, zinc electroplating solution (Ishihara Yakuhin)
Indium electrolytic plating solution (manufactured by Daiwa Kasei)
These plating solutions are used by appropriately mixing depending on the composition of the solder bumps, or plating is performed in a plurality of stages using a single or a mixture of small varieties.
B) Resin material for mask insulation film
Acrylate dry film (RY-32 series, manufactured by Hitachi Chemical Co., Ltd.)
C) Resin material for underfill
The following (1) (under-fill resin 1) or (2) (under-fill resin 2)
(1) Prepared with the following composition
Main agent: 100 parts by weight of bisphenol F type epoxy resin and 100 parts by weight of naphthalene type epoxy resin
Curing agent: Me.THPA (methyl tetrahydrophthalic anhydride) (KRM-291-5: manufactured by Asahi Denka) 100 parts by weight
Curing accelerator: 0.5 part by weight of imidazole
・ Organic acid: 20 parts by weight of succinic anhydride
Inorganic filler: 334 parts by weight of silica powder
Coupling agent: 1 part by weight of γ-glycidoxypropyltrimethoxysilane and 1 part by weight of hexamethyldisilazane
In the composition described above, the mixing ratio of the inorganic filler and the adhesive composition other than the inorganic filler was such that the amount of inorganic filler was 0.50 to 70% by weight, and the remainder was the adhesive composition.
[0043]
(2) Silica powder (average particle size 4 μm) mixed with epoxy-based flux fill (Senju Metal) at a ratio of 50 to 80% by weight
D) Wet-back flux for solder metal layer (R5003 manufactured by α Metals) This flux is not essential in each of the following examples.
In addition to the above, the adhesive composition and the inorganic filler in the underfill resin material can be selected from the following materials.
[0044]
・ Main agent: Alicyclic epoxy resin, bisphenol A type epoxy resin, biphenyl type epoxy resin, novolac type epoxy resin
・ Activators: Succinic acid, sebacic acid, adipic acid, stearic acid, palmitic acid, maleic acid, acetic anhydride, tetraethylene glycol, polyethylene glycol
Coupling agent: β- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyl propyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopyropyltrimethoxysilane, hexa Methyl disilazane, silicon coupling agent / curing accelerator: imidazole (2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 1- Benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-methyl-2-ethylimidazole), organic phosphine (triphenylphosphine, trimethallylphos) Phi , Tetraphenylphosphonium tetraphenyl borate, triphenylphosphine triphenyl borane), diazabicyclo down den Sen, diazabicyclo down den St. Lien sulfonate, diazabicyclo down Den Sen octylate 0.1-40 overlapping portion
Curing agent: methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylhymic anhydride, hexahydrophthalic anhydride, trialkyltetrahydrophthalic anhydride, tetrahydrophthalic anhydride, methylcyclohexenedicarboxylic acid, nadic anhydride
Addition amount is calculated by the amount of epoxy, etc.
・ Inorganic filler: silica, alumina
Specific Example 1
A dry film having a film thickness of 30 μm is pasted at 100 ° C. on the surface of a semiconductor wafer in which 2000 pad electrodes having a diameter of 30 μm are arranged at a pitch of 50 μm and a plurality of semiconductor element regions arranged in a matrix at the periphery are adhered at 100 ° C. Development was performed to form an opening having a diameter of 30 μm on the pad electrode, thereby forming a resist mask. As the developer at this time, n-methyl 2-pyrrolidone was used. A tin-bismuth (Sn-Bi) solder metal layer was formed in the opening of the resist mask by electrolytic plating so that the film thickness was about 40 ± 1 μm. In this case, the composition example of the Sn—Bi solder metal layer has a Bi content of 57% by weight. The melting point of this Sn—Bi solder metal layer was 139 ° C. (The same applies to the following examples). Flux was applied to the solder metal layer, heated at a maximum temperature profile of 200 ° C., and wet-backed to form solder bumps. After that, the resist mask was removed using a 5% monoethanolamine aqueous solution. The semiconductor wafer from which the resist mask was removed was cut and separated into individual semiconductor element regions using a known dicing machine, and the semiconductor elements were cut out.
[0045]
Next, using an ordinary bonder, position the semiconductor element and the wiring board so that the Sn-Bi solder bumps formed on the semiconductor element (chip) and the counter electrode formed on the wiring board face each other. Combined and thermocompression bonded at a temperature of 129 ° C. for 20 seconds. Thereafter, the underfill resin was filled between the semiconductor element and the wiring board and heated at a temperature of 200 ° C. for 2 minutes. This temperature is set relatively high while the eutectic temperature of the Sn—Bi alloy with Bi of 57% is 139 ° C. This is because the solder metal layer formed by electrolytic plating does not necessarily have a uniform alloy composition at the initial stage and the final stage due to a change in the composition of the plating solution accompanying the progress of plating. Of course, the temperature margin may be set smaller depending on the uniformity of the composition. Moreover, the load applied to the thermocompression bonding under the above conditions was about 1.5 kg per chip.
[0046]
As a result, it was confirmed that a good electrical connection was obtained between the semiconductor element and the wiring board. As a connection reliability test, a temperature cycle test of −55 ° C. to 125 ° C. was performed 2000 cycles. As a result, the increase in resistance at the joint portion was as good as 10% or less at maximum.
Specific Example 2
A dry film having a film thickness of 25 μm is pasted at 100 ° C. on the surface of a semiconductor wafer in which 2000 pad electrodes having a diameter of 20 μm are arranged at a pitch of 40 μm and a plurality of semiconductor element regions are arranged in a matrix at the periphery, and exposure and Development was performed to form an opening having a diameter of 20 μm on the pad electrode, thereby forming a resist mask. As the developer at this time, n-methyl 2-pyrrolidone was used. A tin-bismuth (Sn-Bi) solder metal layer was formed in the opening of the resist mask by electrolytic plating so that the film thickness was about 35 ± 1 μm. Flux was applied to the solder metal layer, heated at a maximum temperature profile of 200 ° C., and wet-backed to form solder bumps. After that, the resist mask was removed using a 5% monoethanolamine aqueous solution. The semiconductor wafer from which the resist mask was removed was cut and separated into individual semiconductor element regions using a known dicing machine, and the semiconductor elements were cut out.
[0047]
Next, using a normal bonder, the semiconductor element and the wiring board are aligned so that the Sn-Bi solder bump formed on the semiconductor element and the counter electrode formed on the wiring board face each other. Thermocompression bonding was performed at a temperature of 129 ° C. for 20 seconds. Thereafter, the underfill resin was filled between the semiconductor element and the wiring board and heated at a temperature of 200 ° C. for 2 minutes. Under the above conditions, the load applied to thermocompression bonding was about 1.5 kg per chip.
[0048]
As a result, it was confirmed that a good electrical connection was obtained between the semiconductor element and the wiring board. As a connection reliability test, a temperature cycle test of −55 ° C. to 125 ° C. was performed 2000 cycles. As a result, the increase in resistance at the joint portion was as good as 10% or less at maximum.
Specific Example 3
A dry film having a film thickness of 50 μm is pasted at 100 ° C. on the surface of a semiconductor wafer in which 2000 pad electrodes having a diameter of 50 μm are arranged at a pitch of 100 μm and a plurality of semiconductor element regions arranged in a matrix at the periphery are adhered at 100 ° C. Development was performed to form an opening having a diameter of 50 μm on the pad electrode, thereby forming a resist mask. As the developer at this time, n-methyl 2-pyrrolidone was used. A tin-silver (Sn-Ag) solder metal layer was formed in the opening of the resist mask by electrolytic plating so that the film thickness was about 60 ± 6 μm. Flux was applied to the solder metal layer, heated at a maximum temperature profile of 250 ° C., and wet-backed to form solder bumps. After that, the resist mask was removed using a 5% monoethanolamine aqueous solution. The semiconductor wafer from which the resist mask was removed was cut and separated into individual semiconductor element regions using a known dicing machine, and the semiconductor elements were cut out.
[0049]
Next, using a normal bonder, the semiconductor element and the wiring board are aligned so that the Sn-Ag solder bumps formed on the semiconductor element face the counter electrodes formed on the wiring board, respectively. Thermocompression bonding was performed at 210 ° C. for 20 seconds. Thereafter, the underfill resin was filled and heated at a temperature of 250 ° C. for 2 minutes. The eutectic temperature of the Sn-Ag alloy with 3.5% Ag is 221 ° C. Under the above conditions, the load applied to thermocompression bonding was about 2.0 kg per chip.
[0050]
As a result, it was confirmed that a good electrical connection was obtained between the semiconductor element and the wiring board. As a connection reliability test, a temperature cycle test of −55 ° C. to 125 ° C. was performed 2000 cycles. As a result, the increase in resistance at the joint portion was as good as 10% or less at maximum.
Specific Example 4
A dry film having a film thickness of 50 μm is pasted at 100 ° C. on the surface of a semiconductor wafer in which 2000 pad electrodes having a diameter of 50 μm are arranged at a pitch of 100 μm and a plurality of semiconductor element regions arranged in a matrix at the periphery are adhered at 100 ° C. Development was performed to form an opening having a diameter of 50 μm on the pad electrode, thereby forming a resist mask. As the developer at this time, n-methyl 2-pyrrolidone was used. An indium (In) solder metal layer was formed in the opening of the resist mask by electrolytic plating so that the film thickness was about 70 ± 5 μm. Flux was applied to the solder metal layer, heated at a maximum temperature profile of 250 ° C., and wet-backed to form solder bumps. After that, the resist mask was removed using a 5% monoethanolamine aqueous solution. The semiconductor wafer from which the resist mask was removed was cut and separated into individual semiconductor element regions using a known dicing machine, and the semiconductor elements were cut out.
[0051]
Next, using a normal bonder, the semiconductor element and the wiring board are aligned so that the In solder bumps formed on the semiconductor element face the counter electrodes formed on the wiring board, respectively, and the temperature is 148. Thermocompression bonding was performed at 20 ° C. for 20 seconds. Thereafter, the underfill resin was filled and heated at a temperature of 200 ° C. for 2 minutes. The melting point of In is 157 ° C. Under the above conditions, the load applied to thermocompression bonding was about 1.5 kg per chip.
[0052]
As a result, it was confirmed that good electrical connection was obtained between the semiconductor substrate and the wiring substrate. As a connection reliability test, a temperature cycle test of −55 ° C. to 125 ° C. was performed 2000 cycles.
In each of the specific embodiments described above, the case where the solder bumps are formed on the semiconductor element has been described. However, the present invention can be implemented without changing the semiconductor element and the wiring board.
Specific Example 5
A dry film having a film thickness of 25 μm made of an acrylate resin is applied to the surface of a semiconductor wafer in which 2000 pad electrodes with a diameter of 30 μm are arranged at a pitch of 50 μm and a plurality of semiconductor element regions arranged in a matrix at the periphery are defined. The resist mask was formed by pasting at 0 ° C., exposing and developing to form an opening having a diameter of 10 μm on the pad electrode. As the developer at this time, n-methyl 2-pyrrolidone was used. An indium (In) layer was formed in the opening of the resist mask by electrolytic plating so that the film thickness was about 5 ± 1 μm. A flux was applied to the indium layer thus formed, heated at a maximum temperature profile of 190 ° C., and wet-backed to form solder bumps. After that, the resist mask was removed using a 5% monoethanolamine aqueous solution. The semiconductor wafer from which the resist mask was removed was cut and separated into individual semiconductor element regions using a known dicing machine, and the semiconductor elements were cut out.
[0053]
On the other hand, a dry film having a film thickness of 25 μm made of an acrylate resin was attached to the surface of a wiring board having 2000 pad electrodes with a diameter of 30 μm at a pitch of 50 μm and arranged in a matrix at the periphery at 100 ° C. Development was performed to form an opening having a diameter of 30 μm on the pad electrode, thereby forming a resist mask. As the developer at this time, n-methyl 2-pyrrolidone was used. A tin-bismuth (Sn—Bi) solder metal layer was formed in the resist mask opening by electrolytic plating so that the film thickness was about 35 ± 1 μm. Flux was applied to the solder metal layer, heated at a maximum temperature profile of 200 ° C., and wet-backed to form solder bumps. After that, the resist mask was removed using a 5% monoethanolamine aqueous solution.
[0054]
Next, the semiconductor element and the wiring board are aligned so that the In solder bumps formed on the semiconductor element face the Sn-Bi solder bumps formed on the wiring board, and a normal bonder is used as the semiconductor. The In solder bump and the Sn-Bi solder bump were thermocompression bonded by contacting the back surface of the element and pressing at a temperature of 135 ° C. for 10 seconds. Thereafter, the underfill resin was filled and heated at a temperature of 200 ° C. for 2 minutes. The melting point of In is 157 ° C.
[0055]
The applied load in the thermocompression bonding was about 0.5 kg per chip. This value was 1/3 of the applied load in the specific examples 1 to 4 described above. Moreover, the peak temperature of the wiring board at the time of thermocompression bonding was 98 degreeC, and it turned out that it is 30 degreeC or more lower than the case of specific Examples 1-4.
As a result, it was confirmed that a good electrical connection was obtained between the semiconductor substrate and the printed circuit board. As a connection reliability test, a temperature cycle test of −55 ° C. to 125 ° C. was performed for 500 cycles.
Specific Example 6
A dry film having a film thickness of 25 μm made of an acrylate resin is applied to the surface of a semiconductor wafer in which 2000 pad electrodes with a diameter of 30 μm are arranged at a pitch of 50 μm and a plurality of semiconductor element regions arranged in a matrix at the periphery are defined. The resist mask was formed by pasting at 0 ° C., exposing and developing to form an opening having a diameter of 10 μm on the pad electrode. As the developer at this time, n-methyl 2-pyrrolidone was used. An In-48 wt% Sn solder metal layer made of indium (In) and 48 wt% tin (Sn) was formed in the opening of the resist mask by electrolytic plating so as to have a film thickness of about 5 ± 1 μm. A flux was applied to the indium-tin solder metal layer thus formed, heated at a maximum temperature profile of 147 ° C., and wet-backed to form solder bumps. After that, the resist mask was removed using a 5% monoethanolamine aqueous solution. The semiconductor wafer from which the resist mask was removed was cut and separated into individual semiconductor element regions using a known dicing machine, and the semiconductor elements were cut out.
[0056]
On the other hand, a dry film having a film thickness of 25 μm made of an acrylate resin was attached to the surface of a wiring board having 2000 pad electrodes with a diameter of 30 μm at a pitch of 50 μm and arranged in a matrix at the periphery at 100 ° C. Development was performed to form an opening having a diameter of 30 μm on the pad electrode, thereby forming a resist mask. As the developer at this time, n-methyl 2-pyrrolidone was used. A tin-bismuth (Sn—Bi) solder metal layer was formed in the resist mask opening by electrolytic plating so that the film thickness was about 35 ± 1 μm. Flux was applied to the solder metal layer, heated at a maximum temperature profile of 200 ° C., and wet-backed to form solder bumps. After that, the resist mask was removed using a 5% monoethanolamine aqueous solution.
[0057]
Next, the semiconductor element and the wiring board are aligned so that the In-Sn solder bumps formed on the semiconductor element face the Sn-Bi solder bumps formed on the wiring board, respectively. Was brought into contact with the back surface of the semiconductor element, and the In-Sn solder bump and the Sn-Bi solder bump were thermocompression bonded by applying pressure at a temperature of 110 ° C. for 10 seconds. Thereafter, the underfill resin was filled and heated at a temperature of 200 ° C. for 2 minutes. Note that In48wt% -Sn has a melting point of 117 ° C. Under the above conditions, the load applied to thermocompression bonding was about 0.5 kg per chip. Moreover, the peak temperature of the wiring board at the time of thermocompression bonding was 78 degreeC, and it turned out that it is 50 degreeC or more lower than the case of specific Examples 1-4.
[0058]
As a result, it was confirmed that a good electrical connection was obtained between the semiconductor substrate and the printed circuit board. As a connection reliability test, a temperature cycle test of −55 ° C. to 125 ° C. was performed for 500 cycles.
Specific Example 7
A dry film having a film thickness of 25 μm made of an acrylate resin is applied to the surface of a semiconductor wafer in which 2000 pad electrodes with a diameter of 30 μm are arranged at a pitch of 50 μm and a plurality of semiconductor element regions arranged in a matrix at the periphery are defined. The resist mask was formed by pasting at 0 ° C., exposing and developing to form an opening having a diameter of 10 μm on the pad electrode. As the developer at this time, n-methyl 2-pyrrolidone was used. An In-2.8 wt% Zn solder metal layer composed of indium (In) and 2.8 wt% zinc (Zn) is formed in the resist mask opening by electrolytic plating so that the film thickness is about 5 ± 1 μm. Formed. A flux was applied to the indium-zinc solder metal layer thus formed, heated at a maximum temperature profile of 180 ° C., and wet-backed to form solder bumps. After that, the resist mask was removed using a 5% monoethanolamine aqueous solution. The semiconductor wafer from which the resist mask was removed was cut and separated into individual semiconductor element regions using a known dicing machine, and the semiconductor elements were cut out.
[0059]
On the other hand, a dry film having a film thickness of 25 μm made of an acrylate resin was attached to the surface of a wiring board having 2000 pad electrodes with a diameter of 30 μm at a pitch of 50 μm and arranged in a matrix at the periphery at 100 ° C. Development was performed to form an opening having a diameter of 30 μm on the pad electrode, thereby forming a resist mask. As the developer at this time, n-methyl 2-pyrrolidone was used. A tin-bismuth (Sn—Bi) solder metal layer was formed in the resist mask opening by electrolytic plating so that the film thickness was about 35 ± 1 μm. Flux was applied to the solder metal layer, heated at a maximum temperature profile of 200 ° C., and wet-backed to form solder bumps. After that, the resist mask was removed using a 5% monoethanolamine aqueous solution.
[0060]
Next, the semiconductor element and the wiring board are aligned so that the In-Zn solder bumps formed on the semiconductor element face the Sn-Bi solder bumps formed on the wiring board, respectively. Was brought into contact with the back surface of the semiconductor element, and the In-Zn solder bump and the Sn-Bi solder bump were thermocompression bonded by applying pressure at a temperature of 135 ° C. for 10 seconds. Thereafter, the underfill resin was filled and heated at a temperature of 200 ° C. for 2 minutes. The melting point of In-2.8 wt% Zn is 144 ° C. Under the above conditions, the load applied to thermocompression bonding was about 1.0 kg per chip, which was 2/3 of the specific examples 1 to 4. Moreover, the peak temperature of the wiring board at the time of thermocompression bonding was 98 degreeC, and it turned out that it is 30 degreeC or more lower than the case of specific Examples 1-4.
[0061]
As a result, it was confirmed that a good electrical connection was obtained between the semiconductor substrate and the printed circuit board. As a connection reliability test, a temperature cycle test of −55 ° C. to 125 ° C. was performed 500 cycles. As a result, the increase in resistance at the joint portion was as good as 10% or less.
Specific Example 8
A dry film having a film thickness of 25 μm made of an acrylate resin is applied to the surface of a semiconductor wafer in which 2000 pad electrodes with a diameter of 30 μm are arranged at a pitch of 50 μm and a plurality of semiconductor element regions arranged in a matrix at the periphery are defined. The resist mask was formed by pasting at 0 ° C., exposing and developing to form an opening having a diameter of 10 μm on the pad electrode. As the developer at this time, n-methyl 2-pyrrolidone was used. An In-1.0 wt% Cu solder metal layer composed of indium (In) and 1.0 wt% copper (Cu) is formed in the resist mask opening by electrolytic plating so that the film thickness is about 5 ± 1 μm. Formed. A flux was applied to the indium-copper solder metal layer thus formed, heated at a maximum temperature profile of 150 ° C., and wet-backed to form solder bumps. After that, the resist mask was removed using a 5% monoethanolamine aqueous solution. The semiconductor wafer from which the resist mask was removed was cut and separated into individual semiconductor element regions using a known dicing machine, and the semiconductor elements were cut out.
[0062]
On the other hand, a dry film having a film thickness of 25 μm made of an acrylate resin was attached to the surface of a wiring board having 2000 pad electrodes with a diameter of 30 μm at a pitch of 50 μm and arranged in a matrix at the periphery at 100 ° C. Development was performed to form an opening having a diameter of 30 μm on the pad electrode, thereby forming a resist mask. As the developer at this time, n-methyl 2-pyrrolidone was used. A tin-bismuth (Sn—Bi) solder metal layer was formed in the resist mask opening by electrolytic plating so that the film thickness was about 35 ± 1 μm. Flux was applied to the solder metal layer, heated at a maximum temperature profile of 200 ° C., and wet-backed to form solder bumps. After that, the resist mask was removed using a 5% monoethanolamine aqueous solution.
[0063]
Next, the semiconductor element and the wiring board are aligned so that the In-Cu solder bumps formed on the semiconductor element face the Sn-Bi solder bumps formed on the wiring board, respectively. Was brought into contact with the back surface of the semiconductor element, and pressure was applied at a temperature of 135 ° C. for 10 seconds to thermally press the In—Cu solder bump and the Sn—Bi solder bump. Thereafter, the underfill resin was filled and heated at a temperature of 200 ° C. for 2 minutes. The melting point of In-1.0 wt% Cu is 144 ° C. Under the above conditions, the load applied to thermocompression bonding was about 0.5 kg per chip. Moreover, it turned out that the peak temperature of a wiring board at the time of thermocompression bonding is 110 degreeC, and is 20 degreeC or more lower than the case of specific Examples 1-4.
[0064]
As a result, it was confirmed that a good electrical connection was obtained between the semiconductor substrate and the printed circuit board. As a connection reliability test, a temperature cycle test of −55 ° C. to 125 ° C. was performed for 500 cycles.
Specific Example 9
A dry film having a film thickness of 25 μm made of an acrylate resin is applied to the surface of a semiconductor wafer in which 2000 pad electrodes having a diameter of 20 μm are arranged at a pitch of 40 μm and a plurality of semiconductor element regions arranged in a matrix at the periphery are defined. The resist mask was formed by pasting at 0 ° C., exposing and developing to form an opening having a diameter of 10 μm on the pad electrode. As the developer at this time, n-methyl 2-pyrrolidone was used. A solder metal layer made of indium (In) was formed in the opening of the resist mask by electrolytic plating so that the film thickness was about 5 ± 1 μm. A flux was applied to the indium solder metal layer thus formed, heated at a maximum temperature profile of 187 ° C., and wet-backed to form solder bumps. After that, the resist mask was removed using a 5% monoethanolamine aqueous solution. The semiconductor wafer from which the resist mask was removed was cut and separated into individual semiconductor element regions using a known dicing machine, and the semiconductor elements were cut out.
[0065]
On the other hand, a dry film having a film thickness of 20 μm made of an acrylate resin is attached to the surface of a wiring board having a diameter of 20 μm and having 2000 pads with a pitch of 40 μm and arranged in a matrix at the periphery at 100 ° C. Development was performed to form an opening having a diameter of 20 μm on the pad electrode, thereby forming a resist mask. As the developer at this time, n-methyl 2-pyrrolidone was used. A tin-bismuth (Sn—Bi) solder metal layer was formed in the resist mask opening by electrolytic plating so that the film thickness was about 25 ± 1 μm. Flux was applied to the solder metal layer, heated at a maximum temperature profile of 200 ° C., and wet-backed to form solder bumps. After that, the resist mask was removed using a 5% monoethanolamine aqueous solution.
[0066]
Next, the semiconductor element and the wiring board are aligned so that the In solder bumps formed on the semiconductor element face the Sn-Bi solder bumps formed on the wiring board, and a normal bonder is used as the semiconductor. The In-Cu solder bump and the Sn-Bi solder bump were thermocompression bonded by contacting with the back surface of the element and applying pressure at a temperature of 135 ° C. for 10 seconds. Thereafter, the underfill resin was filled and heated at a temperature of 200 ° C. for 2 minutes. The melting point of In is 157 ° C. Under the above conditions, the load applied to thermocompression bonding was about 0.5 kg per chip, which was 1/3 of that in Examples 1-4. Moreover, it turned out that the peak temperature of the wiring board at the time of thermocompression bonding is 110 degreeC, and is 20 degreeC or more lower than the case of Examples 1-4.
[0067]
As a result, it was confirmed that a good electrical connection was obtained between the semiconductor substrate and the printed circuit board. As a connection reliability test, a temperature cycle test of −55 ° C. to 125 ° C. was performed for 500 cycles.
In each of the above examples, a flux was used when the solder metal layer was etched back, but even if there was no flux, there was almost no difference in the results. Further, as the underfill resin, no difference was observed when either the underfill resin 1 or the underfill resin 2 described in the section of the underfill resin material was used. Furthermore, after the solder bumps are thermocompression bonded to the counter electrode, the underfill resin filled between the semiconductor element and the wiring board is cured and bonded to the counter electrode by melting the solder bump at the same temperature at the same time. However, the solder bump may be melted and solidified after the thermosetting resin is cured at a temperature lower than the melting point of the solder bump.
[0068]
The present invention includes the following aspects.
(Additional remark 1) It is related with the manufacturing method of the semiconductor device which connects the electrode of a semiconductor element, and the electrode of a wiring board, and has an opening part on at least any one of the semiconductor element which has an electrode in a main surface, and a wiring board. Forming an insulating film; forming a metal layer having a height equal to or greater than the thickness of the insulating film in the opening; and melting and solidifying the metal layer by heating to form a first metal bump A step of removing the insulating film after that, a step of thermocompression bonding after aligning the metal bump with the other electrode, and the semiconductor element and the wiring board in which the metal bump and the electrode are thermocompression bonded A step of filling a thermosetting adhesive having a flux action between the two and a step of curing the thermosetting resin by heating and electrically connecting both electrodes by the metal bumps. Features and A method for manufacturing a semiconductor device.
[0069]
(Supplementary note 2) The manufacturing method of the semiconductor device according to supplementary note 1, wherein the composition of the first metal bump includes at least one of tin, silver, bismuth, indium, copper, antimony, gold, and zinc. Method.
(Additional remark 3) The process of forming the insulating film which has an opening part on the said electrode of the said semiconductor metal, the process of forming the metal layer more than the film thickness of this insulating film in this opening, and this metal by heating Melting the layer and then solidifying to form a first metal bump; then removing the insulating film; forming an insulating film having an opening on the electrode of the semiconductor element; Forming a second metal bump in the opening, removing the insulating film thereafter, aligning the first metal bump and the second metal bump, and then thermocompression bonding; The method for manufacturing a semiconductor device according to appendix 1, wherein:
[0070]
(Supplementary Note 4) The manufacturing method of the semiconductor device according to Supplementary Note 3, wherein the composition of the second metal bump includes indium and includes at least one of tin, silver, bismuth, copper, and zinc as a second component. Method.
(Supplementary Note 5) A semiconductor device manufactured by the method according to Supplementary Note 1.
[0071]
(Additional remark 6) The manufacturing method of the semiconductor device of Additional remark 1 characterized by using either the electroplating method or the vapor deposition method for the process of forming a metal layer in the opening part of the said insulating film.
(Additional remark 7) The said metal bump is a metal or alloy which has the melting | fusing point which exists in the range of 100 to 300 degreeC, The manufacturing method of the semiconductor device of Additional remark 1 characterized by the above-mentioned.
[0072]
(Supplementary note 8) The method of manufacturing a semiconductor device according to supplementary note 3, wherein the metal bump formed on the wiring board is a metal or an alloy having a melting point of 138 ° C to 300 ° C.
(Additional remark 9) The said insulating film has photosensitivity, The manufacturing method of the semiconductor device of Additional remark 1 characterized by the above-mentioned.
[0073]
(Supplementary note 10) The method of manufacturing a semiconductor device according to supplementary note 1, wherein the step of thermocompression bonding after aligning the metal bump with the other electrode is performed at a temperature lower than the melting point of the metal bump.
(Supplementary note 11) The method for manufacturing a semiconductor device according to supplementary note 1, wherein the thermosetting adhesive contains an organic acid and contains at least one of a direction filler and an organic filler.
[0074]
(Supplementary note 12) The method of manufacturing a semiconductor device according to supplementary note 1, wherein the first metal bump includes at least one of tin, silver, bismuth, indium, copper, antimony, gold, and zinc.
(Supplementary note 13) The method of manufacturing a semiconductor device according to supplementary note 3, wherein the second metal bump contains indium and contains at least one of tin, silver, bismuth, copper, and zinc as a second component.
[0075]
(Appendix 14) A semiconductor characterized in that a metal bump formed on at least one of a semiconductor substrate and a wiring substrate is bonded to a counter electrode formed on the other by thermocompression bonding at a temperature immediately below the melting point of the metal bump. Device manufacturing method.
(Supplementary note 15) The method of manufacturing a semiconductor device according to supplementary note 14, wherein the temperature in the vicinity of the melting point of the metal bump is in the range between the melting point of the metal bump and a temperature lower by about 20 ° C. from the melting point.
[0076]
(Supplementary Note 16) A thermosetting resin is filled between the semiconductor substrate and the wiring substrate in which the metal bump and the counter electrode are joined by thermocompression bonding, and then the metal bump is applied by applying a temperature higher than the melting point. 15. The method of manufacturing a semiconductor device according to appendix 14, wherein the thermosetting resin is cured while being bonded to the other electrode.
[0077]
【The invention's effect】
According to the present invention, a solder bump formed on one of the semiconductor element and the wiring board is thermocompression bonded to the counter electrode formed on the other at a temperature just below the melting point of the solder bump. Underfill resin is filled between the road substrate and the solder bump is melted by heating in this state to complete the bonding with the counter electrode and the underfill resin is hardened. There is no loss of shape or bridging in the fine solder bumps arranged in density, and the pressing force at the bonding between the semiconductor element and the wiring board can be reduced, and damage to the low-k insulating film is avoided. Furthermore, according to the present invention, in the bump bonding between the semiconductor element and the wiring board, the temperature applied to the wiring board can be reduced, and the reliability of the bonding due to the thermal stress caused by the difference in thermal expansion characteristics from the semiconductor element can be reduced. Can be improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an essential part for explaining the steps of a conventional solder bump forming method.
FIG. 2 is a cross-sectional view of an essential part for explaining a problem in conventional bonding of a bump electrode and a counter electrode.
FIG. 3 is a cross-sectional view of an essential part for explaining the first half of a process in one embodiment of the present invention
FIG. 4 is a fragmentary cross-sectional view for explaining the second half of the process in an embodiment of the present invention.
FIG. 5 is a cross-sectional view of a main part for explaining one of the first half of a process in another embodiment of the present invention.
FIG. 6 is a cross-sectional view of an essential part for explaining the other half of the first half of the process in another embodiment of the present invention.
FIG. 7 is a cross-sectional view of an essential part for explaining the second half of the process in another embodiment of the present invention.
FIG. 8 is a cross-sectional view of an essential part for explaining the difference in effect between two embodiments of the present invention
[Explanation of symbols]
30 Semiconductor elements
32,52 Insulating film
34,54 Pad electrode
36 ', 56' solder layer
36, 56 Solder bump (metal bump)
40 Dry film
42 resist mask
50 Wiring board
60 Underfill resin
70 Bonding tools

Claims (3)

In a method for manufacturing a semiconductor device for connecting an electrode of a semiconductor element and an electrode of a wiring board,
Forming an insulating film having an opening on the electrode of the wiring board;
Forming a metal layer in the opening;
A step of melting the metal layer by heating and then solidifying to form a first metal bump;
A step of removing the insulating film thereafter,
Forming an insulating film having an opening on the electrode of the semiconductor element;
Forming a metal layer in the opening;
A step of melting the metal layer by heating and then solidifying to form a second metal bump having a height lower than that of the first metal bump;
A step of removing the insulating film thereafter,
A step of aligning the first metal bump and the second metal bump and then thermocompression bonding ;
A step of filling a thermosetting adhesive having a flux action between the thermocompression-bonded wiring board and the semiconductor element;
Curing the thermosetting adhesive by heating, and electrically connecting the electrode of the wiring board and the electrode of the semiconductor element by the first metal bump and the second metal bump. A method for manufacturing a semiconductor device. The composition of the first metal bump includes at least one of tin, silver, bismuth, indium, copper, antimony, gold or zinc,
2. The method of manufacturing a semiconductor device according to claim 1, wherein the composition of the second metal bump includes indium and at least one of tin, silver, bismuth, copper, or zinc. The second metal bump has a lower melting point than the first metal bump,
2. The thermocompression bonding of the first metal bump and the second metal bump at a heating temperature at which the second metal bump does not melt at least in the thermocompression bonding step. 3. A method for manufacturing a semiconductor device according to 2.

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