JP3051617B2 - Method for manufacturing semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device in which electrodes of a semiconductor element and electrodes of a wiring board are connected via metal projections.

[0002]

2. Description of the Related Art In recent years, electronic devices equipped with a large number of semiconductor elements have been rapidly increasing. For example, there are a memory card, a liquid crystal display, an EL display, and the like, all of which require a plurality of LSI chips to be mounted on a substrate having a fixed area at a high density and a low thickness. Thus LS
As an effective means for mounting I chips at high density, there is a micro bump bonding method (hereinafter referred to as MBB method). In this method, a metal projection electrode formed on an Al electrode of an LSI chip and a wiring electrode of a wiring board are bonded and connected with a photocurable insulating resin while applying pressure. Are electrically connected to each other. In this method, as described above, it is necessary to directly form a metal projection on the Al electrode of the LSI chip.
Conventionally, as a method of directly forming the metal projection, LS
A multilayer metal film called a barrier metal such as Cr-Cu or Ti-Pd is formed on the Al electrode of the I chip, and a metal projection called a bump is formed on the multilayer metal film by electrolytic plating. However, the A of the LSI chip
In order to form a metal projection directly on an electrode, a number of deposition steps, photolithography steps, and etching steps are required. For this reason, the LSI chip is damaged in the course of these steps, which causes a reduction in yield, and not only increases the mounting cost as a whole, but also lowers the reliability. Furthermore, it is difficult to obtain an LSI chip in which the metal protrusions are formed in advance,
There was a drawback that it lacked versatility.

In order to solve the above problem, as disclosed in Japanese Patent Publication No. 2-7180, for example, a metal projection formed on another substrate is transferred to an Al electrode of an LSI chip by a transfer method.・ There is a joining method.

Hereinafter, this step, together with the step of the MBB method, will be described with reference to FIGS.
FIGS. 5A to 5G are cross-sectional views showing changes in the state in the manufacturing process of the above-mentioned conventional publication. First, FIG.
As shown in (1), a metal projection substrate 21 having a metal projection 22 made of Au is prepared. This metal projection 22
It is mainly formed on the metal projection substrate 21 by the electrolytic plating method. Then, the semiconductor element 23 is placed above the metal projection substrate 21, and the Al electrode 24 of the semiconductor element 23 and the metal projection 22 are aligned.

Next, as shown in FIG. 1B, the metal tool 22 and the Al electrode 24 are brought into contact with each other, and a pressure is applied from the back surface of the semiconductor element 23 by a bonding tool 25.
Heat. By this pressurizing and heating, as shown in FIG. 6A, the alloy layer 32 is placed between the metal projection 22 and the Al electrode 24.
Occurs, and the metal protrusion 22 is bonded to the Al electrode 24. At this time, the temperature is about 380 to 460 ° C., the pressure is 7 to 10 g per metal projection, and the time is about 1 sec. here,
A slight Au-Al alloy layer 32 is formed on the interface layer between the metal protrusion 22 and the Al electrode 24. That is, pressurization and heating are performed with as little pressure, low temperature, and short time as possible so as not to change the shape and size of the metal projection 22 from the state at the time of formation.

Then, as shown in FIG. 1C, the bonding tool 25 is held while the semiconductor element 23 is sucked by a vacuum pump (not shown) through a vacuum suction hole 26 formed in the bonding tool 25. When lifted upward, the metal projection 22 is peeled off from the metal projection substrate 21 and transferred to the Al electrode 24.

Next, as shown in FIG. 1D, the semiconductor element 23 to which the metal protrusion 22 has been transferred and joined in the above-described process is used.
And a wiring substrate 28 having a wiring electrode 27 at a position corresponding to the metal protrusion 22, and a photocurable insulating resin 29 is applied to a region of the wiring substrate 28 where the semiconductor element 23 is located.

After that, as shown in FIG. 1E, the metal projection 22 is pressed against the wiring electrode 27 by the pressure tool 30 at room temperature. At this time, the photocurable insulating resin 29 interposed therebetween is pushed to the periphery, and the metal projection 22 and the wiring electrode 27 are completely electrically connected. At this time, the metal projection 22 needs to be largely deformed in order to complete the connection state. For example, the thickness of the metal projection 22 which was about 10 μm before pressing was 4 to 4 μm.
Deformed to about 5 μm. The load required for this is 90-100 g per metal projection.

Thereafter, as shown in FIG. 1F, ultraviolet rays 31 are irradiated from the back surface or side surface of the wiring board 28 to cure the photocurable insulating resin 29.

Finally, as shown in FIG. 1G, the pressure is released and the connection is terminated. As described above, in the prior art, the bonding between the wiring board 28 and the semiconductor element 23 is pressed without heating,
By fixing both with the photo-curable insulating resin 29, the point which has been a problem so far is improved, and the following features are provided.

1. Since it is a non-heating connection, it can be connected without giving thermal stress.

2. Since the members to be connected are merely pressed (contacted), there is no thermal stress at the joint due to the difference in the coefficient of thermal expansion.

3. Since the connecting portion is hardly joined through a metal bond, it is possible to cope with a narrow pitch.

[0014]

However, the above-mentioned conventional method has the following problems.

First, as described above, as shown in FIG. 6A, the Au-Al alloy layer 32 formed at the interface between the metal projection 22 and the Al electrode 24 in the first transfer / bonding step is an extremely thin layer. It is. This means that the Au—Al alloy layer 32 only has to provide a bonding force necessary for peeling the metal projection 22 from the metal projection substrate 21, and a large deformation of the metal projection 22 causes poor connection in a later step. This is because there is a fear. That is, when a large pressure or high temperature is applied or bonding is performed for a long time, the metal projections 22 mainly formed of columnar crystals formed by electrolytic plating or the like are greatly deformed, and the wiring 27 with the metal projections 22 in the next step is formed. It interferes with the connection. Therefore, the metal protrusion 22 is transferred onto the Al electrode 24 in a state where it is hardly deformed.

Thereafter, as described above, a high load of 90 to 100 g per metal projection is applied without heating, and
Is largely deformed and pressed against the wiring electrode 27 on the wiring board 28 (see FIG. 5E). At this time, as shown in FIG. A done
The u-Al alloy layer 32 is divided due to the large deformation of the metal projection 22 and is scattered near the joint surface between the metal projection 22 and the Al electrode 24. Therefore, most of the portion other than the Au-Al alloy layer 32 near the boundary between the two is not alloyed, resulting in a joint having low strength in reliability.

That is, when a reliability test such as high-temperature storage is performed on the joint formed by this manufacturing method, the electric resistance at the interface between the metal protrusion 22 and the Al electrode 24 increases in a relatively short test time, Further continuation of the test resulted in the regret that the terminal was completely electrically disconnected. In particular,
In a combination in which the wiring board and the semiconductor element have different coefficients of thermal expansion, during use under a high temperature condition, the difference between the coefficients of thermal expansion of the two causes a difference between the Al electrode 24 of the semiconductor element 23 and the metal protrusion 22. Since a large stress acts on the joint, there is a possibility that the joint between the two may be destroyed.

The present invention has been made in view of the above points, and 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 are connected via a metal projection. After performing the transfer and joining by alloying the electrode and the metal projection, the electrode of the semiconductor element and the metal projection are alloyed again with the wiring electrode and the metal projection aligned, and then the metal projection is removed. By connecting the electrode of the semiconductor element and the electrode of the wiring via the electrode, the coupling between the electrode of the semiconductor element and the metal projection can be strengthened without causing a problem at the time of connection between the electrode of the semiconductor element and the electrode of the wiring. Therefore, the purpose is to improve the reliability.

[0019]

In order to achieve the above object, the means specifically adopted in the first aspect of the present invention is a synthetic resin.
A wiring board on which wiring and electrodes of the wiring are formed on a plate ,
As a method of manufacturing a semiconductor device having a semiconductor element mounted on the wiring substrate and having an electrode connected to the electrode of the wiring via the metal projection, a metal projection is formed at a position corresponding to the electrode of the semiconductor element. A preparation step of preparing the provided metal projection substrate in advance; and positioning the semiconductor element and the metal projection with the semiconductor element and the metal projection substrate facing each other. with added pressure to the use substrate pressed against each other, by heating the substrate for a semiconductor <br/> element and the metal projection, the alloy layer between the electrode and the metal projection of the semiconductor element After being formed, a transfer / bonding step of transferring the metal protrusion from the metal protrusion substrate to the electrode of the semiconductor element, and the semiconductor element and the wiring board are opposed to each other and transferred to the electrode of the semiconductor element in the transfer / bonding step. And aligning the electrodes of the joined metal projection and the wiring, each other and the wiring board and the semiconductor element
Applying a pressing force to press against the semiconductor device
By heating and the wiring board, the electrode and the metal of the semiconductor element as the electrode and the metal projection of the semiconductor element becomes stronger bond than in the transfer-bonding step
A re-alloying step of forming an alloy layer of a wider range again between the projections, and in addition to the semiconductor element and the wiring board,
Release the pressing force and heating, and again
Pressing force between the element and the wiring board
In addition, the connection strength between the semiconductor element and the wiring board is strengthened.
Re-pressurizing step, and applying the pressing force
Inject insulating resin from the gap between the conductor element and the wiring board.
And pressurize the insulating resin to cure the insulating resin.
And a connection step of connecting the semiconductor element to the wiring board .

According to a second aspect of the present invention, in the first aspect of the present invention, the re-alloying step is performed by the transfer / transfer step.
This is a method in which a larger pressing force is applied than in the joining step.

According to a third aspect of the present invention, in the first aspect of the present invention, the realloying step is performed by the transfer / transfer step.
This is a method of performing heating to a higher temperature than in the bonding step.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the re-alloying step is performed by the transfer / transfer step.
This is a method in which pressing and heating are performed for a longer time than in the joining step.

[0023]

[0024]

The means adopted by the invention of claim 5 is that, in the invention of claim 1 described above , the electrode of the semiconductor element is made of aluminum.
Alternatively, an Al-based alloy is used, and A is used as an electrode of the wiring board.
This is a method using at least one of u, Ag, Ni or Cu or an alloy thereof.

[0026]

[0027]

According to the above method, in the first aspect of the present invention, in the transfer / bonding step, the electrode of the semiconductor element and the metal projection are pressed and pressed.
When heated, an alloy layer is formed near the boundary between the two, and a bonding state is established. Thereafter, the metal projection is transferred from the metal projection substrate to the electrode of the semiconductor element. And in the re-alloying process,
In a state where the metal projection transferred to the semiconductor element and the electrode of the wiring on the wiring board are in contact with each other, the electrode and the metal projection of the semiconductor element are pressed and heated so as to be in a more firmly bonded state.

In this case, in the transfer / bonding step, the metal projections need only be bonded to the electrodes of the semiconductor element with a minimum bonding strength, so that the degree of deformation can be reduced.
The later step of connecting the semiconductor element to the wiring board will not be disturbed, and in the re-alloying step, the electrode of the semiconductor element and the metal projection are aligned with the metal projection and the electrode of the wiring being aligned. Pressing and heating are performed stronger than in the previous step so that a wide range of alloy layer is formed between the two. that time,
Even if the metal protrusion is greatly deformed, the metal protrusion and the electrode of the wiring are already aligned and in contact with each other, so that a connection failure between the metal protrusion and the electrode of the wiring does not occur. Further, since a wide range of alloy layer is formed between the electrode of the semiconductor element and the metal protrusion, a sufficient alloy layer is secured between the two even if the metal protrusion is greatly deformed later. Therefore,
Strong joint strength can be obtained by alloying between the electrode and the metal projection of the semiconductor element without causing a problem of connection between the semiconductor element and the wiring board due to deformation of the metal projection. Special
In addition, the wiring board is a printed circuit board made of synthetic resin
In some cases, the difference in the coefficient of thermal expansion between the semiconductor element and the printed circuit board is
Because of its large size, it can be semiconductive when placed in a hot environment during use.
Large thermal stress occurs at the connection between the body element and the printed circuit board
However, due to the above-described operation, the electrode of the semiconductor element-the metal projection
Large alloying force can be obtained by re-alloying between
Due to the difference in thermal expansion coefficient between the printed circuit board and the printed circuit board.
The connection state between the parties is prevented from being destroyed.

That is, it is possible to obtain a bonding strength that can sufficiently withstand a stress caused by a difference in thermal expansion coefficient between the semiconductor element and the wiring board, and to obtain an electrode of the semiconductor element during use.
There is no increase in the electric resistance value between the metal protrusions and no occurrence of a non-conductive state, and the reliability is improved.

According to the second aspect of the present invention, since the re-alloying step is performed with a particularly large pressing force, the reaction is promoted under a high pressure condition, so that the re-alloying step covers a wide area near the interface between the electrode of the semiconductor element and the metal projection. The effect of the first aspect of the present invention can be obtained by forming the alloy layer.

According to the third aspect of the present invention, since the re-alloying step is performed by heating to a particularly high temperature, the reaction promoting action under a high temperature condition causes a wide area near the interface between the electrode of the semiconductor element and the metal projection. The effect of the invention of claim 1 is obtained by forming the alloy layer over the range.

According to the fourth aspect of the present invention, since the re-alloying step is performed by heating and pressing for a particularly long time, an alloy layer is formed over a wide range in the vicinity of the interface between the two. Action is obtained.

[0033]

[0034]

[0035] In the invention of claim 5, when the material constituting the electrode of semi-conductor elements is Al or Al alloy, the manufacturing cost is also a good electrical properties and inexpensive. Also, the metal protrusion is A
In the case of u, Cu, Ag or Ni, the electrical resistance between the electrode of the semiconductor element and the electrode of the wiring is small and the plastic deformation ability is moderate, so that the overall characteristics of the semiconductor device are improved.

[0036]

[0037]

FIG. 1A shows an embodiment of the present invention.
This will be described with reference to FIGS.

FIG. 1 is a sectional view for explaining steps of a method of manufacturing a semiconductor device in an embodiment. First, FIG.
As shown in the figure, a semiconductor element 23 is placed above a metal projection substrate 21. The metal projection substrate 21 has a diameter of about 30 μm and a height of 10 μm previously formed by electrolytic plating or the like.
A metal projection 22 made of m Au is mounted at a predetermined position. Then, the positions of the metal projections 22 on the metal projection substrate 21 and the Al electrodes 24 of the semiconductor element 23 are matched.

Then, as shown in FIG. 1B, a bonding tool 25 having a built-in heating mechanism (not shown) is pressed from the back surface of the semiconductor element 23 to bond the metal projection 22 and the Al electrode 24. The tool 25 is pressurized and heated. The pressurizing and heating conditions are as follows.
460 ° C., a pressure of 7 to 10 g per metal projection, and a time of 1 sec. The metal projection 22 on the metal projection substrate 21 is lightly bonded to the Al electrode 24 of the semiconductor element 23 by this pressurization and heating. Is done. Note that bonding tool 2
5 has a heating mechanism, so that the bottom surface of the bonding tool is made of a heat-resistant material.

Next, as shown in FIG. 3C, the semiconductor chip 23 is sucked by a vacuum pump (not shown) through a vacuum suction hole 26 formed in the bonding tool 25 while the bonding tool 25 is being sucked. Is lifted upward, the metal protrusion 22 is peeled off from the metal protrusion substrate 21 and is transferred and joined to the Al electrode 24 of the semiconductor element 23. The steps of FIGS. 1A to 1C are the transfer / joining steps.

At this time, as shown in FIG.
The metal projection 22 made of and the Al electrode 24 are joined by forming a slight Au-Al alloy layer 32 at the interface layer between them. That is, the metal projection substrate 2
Since only the Au—Al alloy layer necessary to peel off the metal protrusions 22 from 1 needs to be formed, the temperature required to form the Au—Al alloy layer 32 required also in terms of the transfer conditions is sufficient. And only take time and pressure. Therefore,
Under these bonding conditions, the metal projections 22 are hardly deformed, and the metal projections 2 having a thickness of about 10 μm before being transferred and joined.
The height of 2 is also only deformed by about 1-2 μm.

Next, as shown in FIG. 1D, a wiring board 28 such as a printed board having a wiring electrode 27 formed below the semiconductor element 23 to which the metal projection 22 has been transferred and joined in the previous step. Is installed. At this time, the formation position of the wiring electrode 27 corresponds to the formation position of the Al electrode 24 of the semiconductor element 23, and the position of the wiring electrode 27 and the position of the Al electrode 24, that is, the position of the metal protrusion 22 are matched. The wiring board 2
8, a silicon substrate or a glass substrate is used, and the material of the wiring electrode 27 is Cr-Au, Ti-Pd-Au, IT
O or the like is used.

Thereafter, the semiconductor element 23 is heated by the bonding tool 25 as shown in FIG.
The metal projection 22 is pressed against the wiring electrode 27 by pressing. The bonding conditions at this time are as follows:
380 to 460 ° C., the same as the temperature in the joining step (the state of FIG. 1B), the applied pressure is about 10 times the applied pressure in the transfer / joining step, and 70 to 100 g per metal projection.
The time is about 1 to 2 seconds. However, if the heating temperature is 3
The temperature may be set to a value higher than that of the transfer step in the previous step in the range of 80 to 460 ° C., and the heating time may be set to 3 to 7 seconds longer than that of the transfer / bonding step. By this step, the metal projection 22 and the Al electrode 24 are alloyed again,
The step shown in FIG. 1E is a re-alloying step. In this embodiment, as the material constituting the surface of the bonding tool 25, a material obtained by coating a ceramic with a diamond thin film was used.

In the re-alloying step, as shown in FIG. 2B, the new Au-Al alloy layer 3 is formed in a wider range than the Au-Al alloy layer 32 formed in the transfer / joining step.
3 are formed, and the metal protrusion 22 and the wiring electrode 27 are more firmly connected. At this time, the metal projection 22 has been deformed until its height becomes about 4 to 5 μm.

Next, as shown in FIG. 1 (f), the pressurization and heating by the bonding tool 25 are released, and the semiconductor element 23 is pressurized again by the pressurizing tool 30 at room temperature. The pressing force at this time is the same as in the realloying step, and is 70
It is about 100 g. At this time, since the metal projections 22 and the wiring electrodes 28 are pressurized at room temperature, no new alloying is performed in this step. The mounting position of 23 becomes highly accurate, and the connection strength becomes strong. Since the pressing tool 30 is not heated, the material forming the bottom surface of the pressing tool 30 does not need to be a heat-resistant material like the bottom surface of the bonding tool 25, and a material that can easily provide relatively high precision flatness. For example, glass or the like is used.

Thereafter, as shown in FIG. 1G, an insulating resin is injected from a gap between the semiconductor element 23 and the wiring board 28. Here, a photo-curable insulating resin 29 is used.
The region into which the photocurable insulating resin 29 is injected is formed by the metal protrusion 22.
May be formed only in the region where the semiconductor element 23 is formed.
It may be over the entire surface. Then, ultraviolet light is irradiated from the back surface or side surface of the wiring substrate 28 to cure the photocurable insulating resin 29.

Thereafter, as shown in FIG. 2H, when the pressure is released, the step of connecting the semiconductor element 23 to the wiring board 28 is completed.

In the above embodiment, the transfer / joining step (FIG. 1)
After (b) and (c)), a re-alloying step (FIG. 1)
(E), the A of the semiconductor element 23 is
The bonding between the l-electrode 24 and the metal protrusion 22 becomes stronger.
That is, as shown in FIG. 2A, in a state where the metal protrusion 22 is transferred and bonded onto the Al electrode 24 of the semiconductor element 23, as much Au- as necessary to transfer the metal protrusion 22.
Only the Al alloy layer 32 is formed at the interface between them.
If the pressurization and heating are performed more strongly than this, the metal protrusions 22 may be greatly deformed, and a connection failure on the wiring board 28 may occur after the transfer. In particular, the metal projection 22 is generally formed by electrolytic plating, and its structure mainly includes columnar crystals extending perpendicularly to the surface. Easy to crumble. Thus, as in the above embodiment, in the transfer / bonding step, the deformation of the metal projection 22 is minimized, that is, the reduction in height is reduced to 1 to 2 μm.
m.

On the other hand, in the re-alloying step, since the wiring electrode 27 of the wiring board 28 is in contact with the lower surface of the metal projection 22, even if the metal projection 22 is greatly deformed, The connection with the electrode 27 is not hindered. Therefore, as shown in FIG.
5, a large pressing force or a high heating temperature, or a long pressurizing and heating time, a wider range of new Au
-The Al alloy layer 33 is formed. At this time, the height of the metal projection 22 is deformed until it becomes about 4 to 5 μm.
By the presence of a sufficient alloy layer at the interface between the electrode and the metal protrusion, the bond between the Al electrode 24 and the metal protrusion 22 becomes extremely strong. Therefore, even if the difference in the coefficient of thermal expansion between the semiconductor element 23 mounted on the wiring board 28 and the wiring board 28 is large, it is effective to break the joint due to a large stress caused by the difference in thermal expansion during use. In addition, it is possible to effectively prevent the increase of the electric resistance and the occurrence of the interruption state.

Next, specific experimental results performed based on the above embodiment will be described. FIG. 3 shows the metal projection 2 when the bonding temperature and the pressing force between the Al electrode and the metal projection were changed.
2 shows the change in shear force (at room temperature) of No. 2. In the drawing, the vertical solid line range indicates the variation range of the measured values for each of 25 samples, and the values marked with ▲ and ● are the average values of the measured values. As you can see from the figure,
It is shown that the shearing force increases as the pressing force increases and the joining temperature increases. However, increasing the joining temperature increases the effect of improving the shear strength.

FIG. 4 shows data obtained by conducting a reliability test on the shear strength per metal projection at a high temperature of 150.degree. C., showing the conventional method including no re-alloying step and the method of the present invention. The method is compared with the method described above. In the drawing, the solid line range in the vertical direction indicates the variation range of the measurement values for each of 25 samples, and the values marked with ，, ●, Δ, and □ are the average values of the measurement values. ，, △, and △ are data of samples joined by the manufacturing method of the present invention, ○ is a sample in which only the pressing force is increased, は is a sample in which the heating temperature is increased, and △ is a time in which the heating temperature is not increased so much. Is the data of a sample with a longer length. Also, □
Is data of a sample joined by a conventional manufacturing method, in which only a pressing step at room temperature was performed without performing a re-alloying step after a transfer / joining step. Specific conditions are described in the figure. As shown in the figure, in the case of the conventional method, the initial shear strength is low, and the shear strength tends to largely decrease by 200 hours. On the other hand, in the case of the present invention, it is shown that the initial shear strength is large and that even when the test time is long, the shear strength hardly deteriorates.

In the above embodiment, the realloying step (see FIG. 1 (e)) and the connecting step (see FIGS. 1 (f) and 1 (g)) are performed separately. It is also possible to do. In this case, the material forming the bottom surface of the bonding tool 25 is made of a heat-resistant material such as ceramic, and the flatness of the surface is extremely excellent. The process shown in FIG. 1 (f) may be performed in a state where the pressure is applied at the same level as the pressing force in the example).

Further, in the above embodiment, the electrode of the semiconductor element of the semiconductor element 23 is the Al electrode 24. However, in practice, this Al electrode 24 is not limited to pure Al.
Al-based alloys such as Cu-Si alloy and Al-Ti-Si alloy are often used. However, not necessarily Al or Al
It is not limited to the system alloy. In the above embodiment, Au is used as the metal projection 22. However, the constituent material of the metal projection 22 is not limited to Au, and other metals can be used. In particular, Cu, Ag, Ni and the like have low electric resistance like Au, and have an appropriate plastic deformation ability, so that they can be interposed between the electrodes of the semiconductor element and the wiring electrodes to facilitate the electrical connection. Suitable to do.

Further, in the above embodiment, the photo-curable insulating resin 29 is used as the insulating resin in the connecting step, and the semiconductor element 2 is used.
Although 3 is connected on the wiring board 28, it goes without saying that a thermosetting resin, another resin, or a conductive material may be used. In that case, as in the above embodiment,
Injecting after re-alloying by pressurization and heating, and in the step shown in FIG. 1 (d), after positioning the metal projections 22 and the wiring electrodes 27, a photocurable As shown in FIG.
After heating and pressing as shown in (e) and (f), there is a method of curing by irradiating or heating with ultraviolet rays as shown in FIG.

[0055]

As described above, according to the first aspect of the present invention , the wiring and the electrodes of the wiring are formed on the synthetic resin plate.
As a method of manufacturing a semiconductor device in which a semiconductor element is mounted on a wiring board, a preparation step of forming a metal projection on a substrate for a metal projection in advance, and pressing and contacting the electrode of the semiconductor element with the metal projection are performed. After heating and alloying, a transfer / joining step of transferring the metal protrusions from the substrate for metal protrusions to the electrodes of the semiconductor device, and, in a state where the metal protrusions and the electrodes of the wiring are in contact, the electrodes of the semiconductor device and metal protrusions And a connection step of connecting the metal projections and the electrodes of the wiring so that the metal projections and the electrodes of the wiring are electrically connected to each other. A strong bond strength is obtained by re-alloying between the electrode and the metal projection of the semiconductor element without causing any trouble during the process, so that the stress due to the difference in thermal expansion coefficient between the semiconductor element and the wiring board can be reduced. Ten Bonding strength to withstand can be secured, and the electrodes of the semiconductor element during use - to effectively prevent the occurrence of increased and interruption states of the electrical resistance between the metal projections, it is possible to improve the reliability.

According to the second aspect of the present invention, in the manufacturing method of the first aspect, the re-alloying step is performed with a particularly large pressing force. An alloy layer can be formed over a wide range in the vicinity of the interface between the electrode and the metal projection, so that the effect of the first aspect of the invention can be effectively exhibited.

According to the third aspect of the present invention, in the manufacturing method of the first aspect , the re-alloying step is performed at a particularly high temperature. An alloy layer can be formed over a wide range in the vicinity of the interface between the metal layer and the metal projection, and the effect of the first aspect of the present invention can be effectively exhibited.

According to the fourth aspect of the present invention, in the manufacturing method of the first aspect , since the re-alloying step is performed by pressing and heating for a long time, the semiconductor can be reacted by a long time. An alloy layer can be formed over a wide range in the vicinity of the interface between the electrode of the element and the metal projection, so that the effect of the first aspect of the invention can be effectively exhibited.

[0059]

[0060]

According to a fifth aspect of the present invention, in the manufacturing method of the first aspect , Al or an Al-based alloy is used as the electrode of the semiconductor element of the semiconductor element, and Au, C is used as the metal projection.
Since u, Ag, or Ni is used, a semiconductor device having good overall characteristics can be manufactured at low cost.

[0062]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a change in a state in a manufacturing process of a semiconductor device in an example.

FIG. 2 shows Au— in a transfer / joining step and a re-alloying step.
It is sectional drawing which shows the difference of an Al alloy layer.

FIG. 3 is experimental data showing the dependency of the shear strength between the Al electrode and the metal projection on the pressing force and the joining temperature.

FIG. 4 is data showing the results of a reliability test on samples prepared by the manufacturing method of the present invention and a conventional manufacturing method.

FIG. 5 is a cross-sectional view showing a state change in a conventional semiconductor device manufacturing process.

FIG. 6 is a cross-sectional view showing a change of an Au—Al alloy layer in a transfer / joining step and a connecting step according to a conventional manufacturing method.

[Explanation of symbols]

 Reference Signs List 21 protruding electrode forming substrate 22 protruding electrode 23 semiconductor element 24 Al electrode 25 bonding tool 27 wiring electrode 28 wiring substrate 29 photocurable insulating resin 30 pressing tool 32 Au-Al alloy layer 33 new Au-Al alloy layer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/60 311

Claims (5)

(57) [Claims] 1. A wiring and electrodes of the wiring are formed on a synthetic resin plate.
A method for manufacturing a semiconductor device, comprising: a formed wiring board; and a semiconductor element mounted on the wiring board and having an electrode connected to an electrode of the wiring via a metal protrusion, the method comprising: A preparation step in which a metal projection substrate having a metal projection provided at a position corresponding to the electrode is prepared in advance; and the semiconductor element and the metal projection substrate are opposed to each other, and the electrode of the semiconductor element is aligned with the metal projection. to, with addition of pressing force pressed against each other and a substrate for the semiconductor element and the metal projection, the semiconductor device and the metal projection for group
After heating the plate and forming an alloy layer between the electrode of the semiconductor element and the metal projection, a transfer / bonding step of transferring the metal projection from the substrate for metal projection to the electrode of the semiconductor element, The semiconductor element and the wiring board are opposed to each other, and the metal projection transferred and joined to the electrode of the semiconductor element in the transfer and joining step is aligned with the electrode of the wiring, so that the semiconductor element and the wiring board are aligned with each other. When you apply pressing force
Moni by heating and the semiconductor element and the wiring substrate, the semiconductor element as the electrode and the metal projection of the semiconductor element becomes stronger bond than in the transfer-bonding step
A re-alloying step of forming an alloy layer of a wider range again between the electrode of the semiconductor and the metal projection, and pressing and heating applied to the semiconductor element and the wiring substrate
And again, at normal temperature, the semiconductor element and the wiring board
Between the semiconductor elements
Re-pressing step to strengthen the connection strength between the chip and the wiring board
And the semiconductor element and the wiring base in a state where the pressing force is applied.
Insulating resin is injected from the gap between the board and the insulating resin.
After curing, release the pressing force and apply to the wiring board.
And a connection step of connecting the semiconductor elements . 2. The method of manufacturing a semiconductor device according to claim 1, wherein the re-alloying step is performed so as to apply a larger pressing force than in the transfer / joining step. Method. 3. The method of manufacturing a semiconductor device according to claim 1 , wherein said re-alloying step is performed so as to heat to a higher temperature than in the transfer / joining step. Method. 4. The method of manufacturing a semiconductor device according to claim 1 , wherein the re-alloying step is performed so as to press and heat for a longer time than in the transfer / joining step. Manufacturing method for equipment. 5. The method of manufacturing a semiconductor device according to claim 1 , wherein Al or an Al-based alloy is used as an electrode of said semiconductor element, and Au, Ag, Ni or Cu or an alloy thereof is used as an electrode of said wiring board. A method for manufacturing a semiconductor device, comprising using at least one of the following.