JPH0574857A - Semiconductor device - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent the occurrence of cracks and peeling in the connection terminals due to stress caused by the difference in thermal expansion coefficient. [Structure] In a semiconductor device in which a silicon pellet 11 is CCBed on a substrate 21, a connection terminal 34 is constructed based on a bump main body 17 made of soft silicone rubber. [Effect] The substrate 21 and the pellet 1 at the time of thermal fluctuation based on the difference in thermal expansion coefficient between the alumina ceramic and silicon
Since the difference in the deformation amount with respect to No. 1 can be absorbed by the elastic deformation of the soft bump main body 17, the stress acting on the connection terminal 34 can be suppressed or suppressed by the difference in the deformation amount. As a result, it is possible to prevent the occurrence of peeling and cracks in the connection terminals 34 formed by CCB.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, particularly a semiconductor pellet (hereinafter referred to as pellet or chip).
Relates to a semiconductor device bonded to an insulating substrate (hereinafter, simply referred to as a substrate) by a flip chip method. That is, the technology effectively applied to a semiconductor device that is mechanically and electrically connected to each other.

[0002]

2. Description of the Related Art The flip chip method is a name given by so-called face-down bonding, in which a chip is turned upside down and bonding is performed using connection terminals formed on the surface or substrate. The flip chip method includes a ball method in which a metal ball is attached to a chip, a bump method in which a protruding electrode is formed of aluminum or a silver alloy, or a pedestal method in which a pedestal is attached to a substrate, depending on the form of the connection terminal to be formed.

The ball-type flip-chip structure is characterized in that a considerably thick low-melting glass is used as a chip protective film and that bumps for electrode connection (protruding electrodes, Bum) are used.
p) is formed from a solder (Pb-Sn) which covers the surface of a Cu ball plated with Ni and Au. In the manufacturing method, first, the surface of a conventional planar element having an Al electrode is covered with protective glass. Next, the glass film of the electrode portion is removed, an electrode base is formed of a multi-layer metal of Cr-Cu-Au, and Cu balls plated with Ni and Au are placed on the electrode base to form bumps welded by solder. This method is not suitable for a chip having a large number of electrodes because it is connected via Cu balls.

Therefore, an improved version of this system is also a controlled collapse reflow chip. This is one in which hemispherical bumps are formed by using Sn-Pb instead of the Cu balls of the above method. The bump is formed on the Al pad via a barrier metal (Cr-Cu-Au). In order to prevent excessive solder flow during bonding, a chip having a pad that is not connected to internal wiring has been devised.

Flip chips made of Al or Ag-Sn bumps are easy to work with Al and Ag alloys.
It is used because it is easy to obtain bonding conditions. The manufacturing method is the same as the above-mentioned ball method until the wafer having the internal wiring is covered with the glass film or the SiO ₂ film and the window for the electrode is opened by the photoresist technique. next,
After thinly depositing Cr or Ti as an adhesive metal,
The bump metal is attached and the bump portion is left to be removed by etching. The adhesion thickness of the bump metal is determined by the balance between the etching yield and the bondability, and is generally about 25 μm. Also, the size of the bump is limited by the chip size. There is also a flip chip using solder instead of Al and Ag—Sn.

An example of the flip-chip technology is "IC mounting technology" issued by the Industrial Research Institute Co., Ltd.
Published January 15, 1980 P81, P103 to P10
There are five.

[0007]

However, in the conventional flip-chip type semiconductor device, repeated stress acts on the connection terminal portion due to the difference in thermal expansion coefficient between the pellet and the substrate, so that the pellet does not adhere to the substrate. There is a problem that peeling or cracking occurs in the connection terminal portion due to a temperature cycle during bonding or during operation of the semiconductor device.

Therefore, in order to reduce the thermal stress due to the difference in the thermal expansion coefficient, the thermal expansion coefficient of the substrate is adjusted to the thermal expansion coefficient of the pellet as much as possible. In the case of this solution, since the selection condition of the substrate is determined by the thermal expansion coefficient, other physical properties other than the thermal expansion coefficient such as thermal conductivity, insulation performance, dielectric constant, adhesion with wiring, hygroscopicity, etc. However, there is a problem in that a material having excellent properties cannot be used as a substrate forming material.

An object of the present invention is to provide a semiconductor device capable of preventing the occurrence of cracks and peeling at a connection terminal due to stress associated with the difference in thermal expansion coefficient while avoiding restrictions on the substrate regarding the thermal expansion coefficient. It is in.

As a mounting technique for mounting pellets having bumps on a mounting substrate, an anisotropic conductive film is bonded to the mounting substrate, and the pellets are placed on the anisotropic conductive film with the bump groups in contact. At the same time, there is a technology to electrically connect the pellets to the mounting board through the electrical paths of the bumps and the anisotropic conductive film by pressing the bumps against the anisotropic conductive film by contraction of the photo-curable adhesive. ,Proposed.

However, in the semiconductor device using this anisotropic conductive film, the electrical connection between the pellet and the substrate is ensured by the contact between each bump and the anisotropic conductive film. However, there is a problem in that the inter-electrode pitch is restricted by the performance of the anisotropic conductive film.

A second object of the present invention is to provide a semiconductor device which can surely electrically connect the pellet and the substrate and can set the pitch between the electrodes small.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0014]

The typical ones of the inventions disclosed in the present application will be outlined below.

That is, in a semiconductor device in which a semiconductor pellet having an electronic circuit built therein is mechanically and electrically connected to an insulating substrate via a connection terminal, the connection terminal is connected to an electrode pad of the semiconductor pellet. The bump main body is made of a soft material so as to project, and a bump formed by applying a conductive coating to the surface of the main body so as to electrically connect to the electrode pad is soldered to the pad of the insulating substrate. It is characterized by being formed by.

[0016]

According to the above means, since the bump body is made of the soft material, the mechanical stress generated by the difference in the thermal expansion coefficient between the semiconductor pellet and the substrate is absorbed by the deformation of the bump body. Due to the deformation absorbing effect of the bump body, it is possible to prevent the stress generated due to the difference in thermal expansion coefficient between the semiconductor pellet and the substrate from concentrating on the connection terminal, so that peeling or cracks occur at the connection terminal. Can be prevented in advance.

[0017]

1 is an enlarged partial sectional view showing a semiconductor device according to an embodiment of the present invention, FIG. 2 is a perspective view showing a semiconductor pellet used therein, and FIG. 3 is an enlarged partial sectional view thereof.
4, 5, and 6 are enlarged partial plan views and enlarged partial vertical cross-sectional views showing a bump forming process, and FIG. 7 is a partially cutaway perspective view showing a substrate used in the semiconductor device of FIG.
Is an enlarged partial sectional view thereof, and FIGS. 9 and 10 are explanatory views for explaining the stress generation preventing action.

In this embodiment, in the semiconductor device according to the present invention, a silicon pellet (hereinafter referred to as a pellet) 11 as a semiconductor pellet in which an integrated circuit is built is used.
Computer module substrate (hereinafter referred to as substrate) 2
1 is configured to be mechanically and electrically connected by a plurality of connection terminals 34 formed by CCB. The most important feature of this semiconductor device is that the connection terminals 34 are the electrode pads 14 of the semiconductor pellets 11.
The bump main body 17 is made of a soft material and protrudes from the bump main body 17, and the conductor coating 19 is formed on the surface of the bump main body 17.
Is formed by being soldered to the pads 32 of the insulating substrate 21 so that the bumps 12 formed by being electrically connected to the electrode pads 16A are soldered to the pads 32 of the insulating substrate 21.

The semiconductor device is manufactured by the following manufacturing method. Hereinafter, a method of manufacturing this semiconductor device will be described. This description clarifies details of the configuration of the semiconductor device.

In this embodiment, the pellet 11 shown in FIG. 2 is used, and a plurality of bumps 12 for forming the connection terminal 34 are formed on the main surface of the connection side of the pellet 11.
It is formed by arranging at predetermined intervals. The manufacturing work of pellets and bumps is performed in the form of a wafer in a so-called pre-process in the manufacturing process of a semiconductor device. Hereinafter, the manufacturing process of the pellets will be briefly described, mainly the forming process of the bumps 12.

In a pre-process of a so-called semiconductor device manufacturing process, a desired integrated circuit (not shown) is formed in a wafer form so as to correspond to each pellet 11. Next, in the electric wiring forming step, the electric wiring 14 is formed on the insulating film 13 of the integrated circuit. Aluminum is used for the work of forming the electric wiring 14, and the work is performed by an appropriate thin film forming process such as sputtering or vapor deposition and a lithographic process. A passivation film 15 is deposited on the electric wiring 14. Usually, the passivation film 15 is composed of a hard insulating film such as a silicon oxide film or a silicon nitride film.

A plurality of (9 in this embodiment) through holes 16 are arranged in the passivation film 15 at predetermined locations spaced from each other, respectively. In this embodiment, as shown in FIG. 4, each through hole 16 is formed in a circular ring shape having an outer peripheral diameter of 200 μm and an inner peripheral diameter of 150 μm. Predetermined electric wiring 14 is exposed on the bottom surface of each opened through hole 16, and therefore the through hole 16 substantially constitutes an electrode pad 16A. The work of opening the through hole 16 is selectively performed by a lithography process.

Thereafter, in the bump forming process, a thin film forming process and a lithographic process are used to electrically connect the bumps 12 to the electrode pads 16A, that is, the electric wirings 14 in the through holes 16 of the pellet 11. To be formed respectively. In the present embodiment, as shown in FIG. 3, the bump 12 is made of a soft material having an insulating property, and is formed in a hemispherical shape so as to project from the bump body 17. A ring-shaped through hole is formed from the bump body 17. Base layer 18 formed over 16
And the electrode pad 16A, which is attached from the bump body 17 to the outside of the through hole 16 through the underlayer 18.
That is, it is composed of a conductor film 19 electrically connected to the electric wiring 14, and a preliminary solder layer 20 attached to the surface of the conductor film 19.

The bump body 17 is made of silicone rubber as a soft material having an insulating property and is formed on the inner disk-shaped portion of the through hole 16 by the potting molding method as shown in FIGS. 4 and 5. It is formed in a hemispherical shape. That is, when the liquid silicone rubber is potted on the inner disk-shaped portion of the through hole 16, the hemispherical bump body 17 having the disk shape of the through hole 16 as a radius is formed by the surface tension thereof. ..

After the bump body 17 is formed in this way, as shown in FIG. 5, the underlying layer 18 is formed from the hemispherical bump body 17 to the outside of the circular ring-shaped through hole 16. Chromium (Cr) is used as the material, and the through holes 16 are masked on the outside thereof by the vapor deposition method so as to have a thickness of about 50 nm.

Subsequently, as shown in FIG. 6, a conductive coating film 19 is formed on the chromium underlayer 18 by a similar vapor deposition method using copper (Cu) as a constituent material to form a conductive coating film 19 having a thickness of
It is deposited to be about 20 μm.

Then, as shown in FIG. 3, the preliminary solder layer 20 is formed by using a solder material having a melting point capable of effectively executing CCB described later as a constituent material,
A similar vapor deposition method is applied to a thickness of about 2 μm.

The wafer on which the pellets 11 and the bumps 12 are formed as described above is divided into each pellet 11 in the dicing process. The pellet 11 after being diced is formed into a minute flat plate shape corresponding to a pellet mounting region on a substrate 21 described later.

On the other hand, in this embodiment, the substrate 21 as shown in FIGS. 7 and 8 is used. Next, the configuration of the substrate 21 will be described.

The substrate 21 includes a base 22 formed of alumina ceramic, and the base 22 is formed in a rectangular board shape having an appropriate strength and size so that it can be used as a computer module board. There is. In the present embodiment, alumina ceramic is used as the constituent material of the base 22, but not limited to this, it is possible to use ceramics such as silicon carbide, mullite, aluminum nitride, and insulating materials such as epoxy resin. ..

A first insulating layer 23 is laminated on the base 22, and the first insulating layer 23 is formed of polyimide resin in a film shape. This first insulating layer 2
A first electric wiring (hereinafter, referred to as a first wiring) 24 is provided on the surface 3.
Are patterned into a desired shape and wired. In the present embodiment, the first wiring 24 is formed by joining a copper foil on the first insulating layer 23 using titanium as an adhesion metal and selectively patterning by a lithography process.

The second insulating layer 2 is formed on the first insulating layer 23.
5 is laminated, and the second insulating layer 25 is formed in a film shape by using a polyimide resin like the first insulating layer 23. On this second insulating layer 25, a second electric wiring (hereinafter, referred to as a second wiring) 26 is patterned and wired in a desired shape. The second wiring 26 is
It is formed similarly to the first wiring 24.

Further, a plurality of through holes 27 are formed in the second insulating layer 25 by a lithographic process, and each through hole 27 exposes a predetermined electrode portion of the first wiring 24. .. The through-hole conductor 28 is made of the same conductive material as that of the first wiring 24 for each through-hole 27.
It is filled by an appropriate means such as a plating method. Each through-hole conductor 28 has one end (hereinafter referred to as a lower end) electrically connected to each electrode portion of the first wiring 24, and has an upper end at the second insulating layer 2.
5 is exposed.

As shown in FIGS. 7 and 8, a protective insulating layer 29 is laminated on the second insulating layer 25,
The protective insulating layer 29 is made relatively thick using a polyimide resin which is an example of an insulating material having a small lateral elastic modulus. Incidentally, in this embodiment, the protective insulating layer 2
9 has a thickness of about 200 μm and is formed by successive lamination.

The second through hole 3 is formed in the protective insulating layer 29.
A plurality of 0s are formed by the lithography process, and each second through hole 30 exposes each through hole conductor 28 of the first wiring 24 and a predetermined electrode portion of the second wiring 26. ing. The second through-hole conductor 31 is filled with the second through-hole conductor 31 using the same material as that of the wirings 24 and 26, and is filled by an appropriate means such as a vapor deposition method, a sputtering method, or a plating method. The lower ends of the through-hole conductors 31 are electrically connected to the first through-hole conductors 28 and the electrodes of the second wiring 26, respectively, and the upper ends thereof are exposed on the protective insulating layer 29. It is in a state of being.

CCB pads 32 are formed on the upper ends of the respective second through-hole conductors 31. A preliminary solder layer 33 is formed on the pad 32 so that the bump 12 has good wettability with the preliminary solder layer 20. The pads 32 are arranged so as to correspond to the bumps 12 on the pellet 11, and the arrangement group is arranged for the number of pellets 11 mounted on the substrate 21. In this embodiment, the group of pads 32 includes pellets 11 of 10 mm square at a distance between the bumps 12, and the arrangement pitch of the pellets 11 is 12 m.
It is arranged to be m.

In the CCB process, the pellets 11 having the above structure are gang-bonded to the substrate 21 manufactured as described above for each row of the pad 32 groups.
That is, in a face-down state in which the bumps 12 are fitted to the pads 32 that have been subjected to the pre-soldering process, the pellets 11 are aligned with the groups of the pads 32 of the substrate 21 and are temporarily bonded.

Thereafter, the pre-solder layers 20 and 3 of each bump 12 and pad 32 are subjected to an appropriate reflow process.
By melting 3 respectively, each connection terminal 34 is simultaneously formed, respectively, as shown in FIG.
By this group of connection terminals 34, each pellet 11 is transferred to the substrate 21.
And a state in which the integrated circuit is electrically connected to the first wiring 24 and the second wiring 26 via the connection terminal 34 and the through-hole conductors 31 and 28. In this way, the semiconductor device shown in FIG. 1 is manufactured.

Next, the operation will be described. Silicon and alumina ceramics have different coefficients of thermal expansion. That is, the coefficient of thermal expansion of silicon is about 3.5 to 4.0 × 10 ⁻⁶ (1 / °).
K), the coefficient of thermal expansion of alumina ceramic is about 7.2 ×
It is 10 ⁻⁶ (1 / ° K). The coefficient of thermal expansion of the low thermal expansion polyimide insulating layer is 3.0 to 5.0 × 10 ⁻⁶ (1 /
° K), the coefficient of thermal expansion of copper wiring is 17 × 10 ^-6 (1 / °
K). The coefficient of thermal expansion of the substrate 21 in the present embodiment is a composite value of these, and is substantially equal to the coefficient of thermal expansion of the alumina ceramic base 22.

Therefore, when the pellet 11 and the substrate 21 are rigidly connected by the connection terminal 34, CCB
At the same time, when a large thermal fluctuation is applied during operation of the semiconductor device or the like, a large difference occurs in the expansion deformation amount and the contraction deformation amount between the pellet 11 and the substrate 21, so that the connection terminal 34 Stress is applied to the connection terminal 34
The present inventor has clarified that there is a problem that peeling and cracks occur in the. In particular, when the pellet size is as large as 10 mm □ or more, peeling and cracking tend to be remarkable.

FIG. 9 is an explanatory view for explaining the mechanism of this peeling or cracking, where the pellet 11 is the substrate 21.
The state of the conventional example in which the terminals are rigidly coupled by the connection terminals 35 formed by using solder bumps is shown.

As shown in FIG. 9, for example, CC
The expansion position of the pellet 11 and the expansion position of the substrate 21 at the time of B tend to reach the contraction position due to the difference in thermal expansion coefficient when the temperature is lowered to room temperature. At this time, the contraction difference between the pellet 11 and the substrate 21 influences each other to generate strain, and the stress causes the conventional connection terminal 3 due to the solder bump.
Act on 5.

Now, consider the case where the pellet 21 is not deformed but the substrate 21 is deformed. The deformation occurring only in the substrate 21 causes a stress corresponding to (proportional to) the deformation. The stress is applied to the connection terminal 35 as an illegal mechanical force, and a strain corresponding to the stress is generated in the connection terminal 35.

FIG. 9 shows how stress is generated in the connection terminal 34. Pellets 11 for clarity
Shall not be deformed. As can be seen from FIG. 9, large stress is generated in each connection terminal 35 located in the peripheral portion of the pellet 11.

However, since the connection terminals 35 formed by the conventional solder bumps cannot completely follow the deformation of the substrate 21 due to the influence of the rigidity of the pellet 11, the stress of each connection terminal 35 causes the connection terminal 35 itself to have strength and elastic deformation, and When the adhesion limit with the pad 32 is exceeded, cracking or peeling occurs.

In contrast to the above principle, in this embodiment, as shown in FIG. 10, the connection terminal 34 is based on the bump main body 17 formed of silicone rubber. The elastic deformation of the bump body 17 absorbs the difference in the amount of deformation between the pellet 11 and the substrate 21 due to the difference in the coefficient of thermal expansion during thermal fluctuation. As a result, peeling and cracking of the connection terminals 34 are prevented.

That is, during CCB, the substrate 21 is deformed to the state shown in FIG. 10 due to the difference in thermal expansion coefficient between the pellet 11 and the substrate 21, but in this embodiment, the connection terminal 34 is made of soft silicone rubber. As shown in FIG. 10, since the entire connection terminal 34 is deformed by the elastic deformation of the bump body 17 made of soft silicone rubber, the pellet 11 The difference in deformation with the substrate 21 will be absorbed.

In this way, since the connection terminal 34 itself elastically deforms to absorb the difference in deformation between the pellet 11 and the substrate 21, the connection terminal 34 formed between the pellet 11 and the substrate 21 is No stress exceeding the strength, elastic deformation limit, or adhesion limit of the connection terminal 34 acts. As a result, the phenomenon that the connection terminal 34 is peeled off or cracked is prevented in advance.

The semiconductor device according to this example was subjected to a temperature cycle test with a temperature cycle period of 1 cycle / hour and a temperature range of -50 ° C to 100 ° C. No disconnection due to thermal fatigue occurred in the connection terminal 34 based on the bump main body 17 made of rubber.

According to the above embodiment, the following effects can be obtained.
In a semiconductor device in which pellets are CCBed on a substrate, the connection terminals are constructed based on a bump body made of a soft material, so that the substrate and the pellets can be separated during thermal fluctuation based on the difference in thermal expansion coefficient between alumina ceramic and silicon. Since the difference in the amount of deformation of the soft bump body can be absorbed by the elastic deformation of the soft bump body, the stress acting on the connection terminal can be suppressed or suppressed by the difference in the amount of deformation, and as a result, the connection formed by the CCBs. It is possible to prevent the terminal from peeling or cracking.

By preventing the peeling or cracking of the connection terminal due to CCB, the yield of the semiconductor device due to CCB can be increased, and the quality and reliability thereof can be improved.

By forming the soft bump body using the silicone rubber by the potting molding method, it is possible to suppress the cost increase to a small extent and to configure the soft bump body having an extremely large elastic limit.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, as the soft material for forming the soft bump body, not only silicone rubber is used but also epoxy resin, polyimide resin, etc., and soft metal such as lead, etc. may be used.

The soft bump body is not limited to be formed by the potting method, but may be formed by a screen printing method, a spray printing method, an electroless plating method, a vapor deposition method, or the like.

The material for forming the conductor coating to be adhered to the surface of the soft bump body is not limited to copper, but
Aluminum, gold, palladium, platinum, alloys thereof, or the like may be used, and not only chromium but also titanium or the like may be used as the material for forming the adhesion underlayer.

The electric wiring layer is not limited to two layers,
It may be formed in one layer, or may be formed in three or more layers.

The method of flip-chip bonding the pellet to the substrate is not limited to the CCB method,
Other flip chip methods may be used.

In the above description, the case where the invention made by the present inventor is mainly applied to the semiconductor device used for the module of the computer which is the field of application of the background has been described, but the invention is not limited thereto. It can be applied to all semiconductor devices in which pellets are bonded to a substrate by a flip chip method. In particular, the present invention is applied to the case where the difference in thermal expansion coefficient between the pellet and the substrate is large and the pellet size is large, and excellent effects can be obtained.

[0060]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.

In the semiconductor device in which the pellets are CCBed on the substrate, the connection terminals are constructed on the basis of the bump main body made of a soft material, so that the thermal expansion based on the expansion coefficient difference between the substrate constituent material and the pellet constituent material is performed. Since the difference in the deformation amount between the substrate and the pellet at the time of change can be absorbed by the elastic deformation of the soft bump body, the stress acting on the connection terminal can be suppressed or suppressed due to the difference in the deformation amount. It is possible to prevent occurrence of peeling and cracks in the connection terminals formed by the flip chip method.

[Brief description of drawings]

FIG. 1 is an enlarged partial sectional view showing a semiconductor device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a semiconductor pellet used therein.

FIG. 3 is an enlarged partial sectional view thereof.

FIG. 4 is an enlarged partial plan view showing a state after the bump body is formed in the bump forming step.

FIG. 5 is an enlarged partial vertical cross-sectional view showing a state after forming a base layer in a bump forming step.

FIG. 6 is an enlarged partial vertical cross-sectional view showing a state after the conductor coating is applied in the bump forming step.

7 is a partially cutaway perspective view showing a substrate used in the semiconductor device of FIG.

FIG. 8 is an enlarged partial sectional view thereof.

FIG. 9 is an explanatory diagram for explaining the action of preventing stress generation.

FIG. 10 is an explanatory diagram for explaining the action of preventing stress generation.

[Explanation of sign]

11 ... Pellet, 12 ... Bump, 13 ... Insulating film, 14 ...
Electrical wiring, 15 ... Passivation film, 16 ... Through hole, 16A ... Electrode pad, 17 ... Soft bump body, 1
8 ... Underlayer, 19 ... Conductor coating, 20 ... Preliminary solder layer, 2
DESCRIPTION OF SYMBOLS 1 ... Substrate, 22 ... Base, 23 ... 1st insulating layer, 24 ... 1st electric wiring (1st wiring), 25 ... 2nd insulating layer, 26 ... 2nd electric wiring (2nd wiring), 27 ... Through hole , 28 ...
Through-hole conductor, 29 ... Protective insulating layer, 30 ... Second through-hole, 31 ... Through-hole conductor, 32 ... Pad,
33 ... Pre-solder layer, 34 ... Connection terminal, 35 ... Conventional solder bump connection terminal.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomio Yamada 111 No. Nishiyokote-cho, Takasaki-shi, Gunma Hitachi Takasaki factory (72) Inventor Mayumi Kaneko 111 Nishiyoko-cho, Takasaki-shi Gunma Hitachi, Ltd. Takasaki Plant (72) Inventor Takashi Ouma 64 Nagata, Tenuma-cho, Minami-Akita-gun, Akita Prefecture Akita Denshi Co., Ltd. (72) Inventor Tadamoki Sakuraba 64 Naganuma, Tenno-cho, Minami-Akita-gun Akita Prefecture Akita Denshi Co., Ltd.

Claims (3)

[Claims] 1. A semiconductor device in which a semiconductor pellet having an electronic circuit formed therein is mechanically and electrically connected to an insulating substrate via a connection terminal, wherein the connection terminal is an electrode pad of the semiconductor pellet. The bump main body is made of a soft material so as to project, and a bump formed by applying a conductive coating to the surface of the main body so as to electrically connect to the electrode pad is soldered to the pad of the insulating substrate. A semiconductor device which is formed by the above. 2. The electrode pad is formed in a ring shape, and the bump main body is provided inside the ring-shaped electrode pad so as to project from the soft material having an insulating property. 1. The semiconductor device according to 1. 3. The semiconductor device according to claim 2, wherein the bump body is formed by a potting molding method using a soft resin having an insulating property.