JP5023710B2 - Semiconductor device and manufacturing method thereof - Google Patents

Description

  The present invention relates to a bonding material using metal particles having a particle size of 1 to 100 nm as a main bonding agent, and also relates to a semiconductor device bonded using the bonding material.

When the particle size of metal particles is reduced to a size of 100 nm or less and the number of constituent atoms is reduced, the surface area ratio with respect to the volume of the particles increases rapidly, and the melting point and sintering temperature greatly decrease compared to the bulk state. It has been known. Using this low temperature firing function, the particle size is 1-100
The use of nm metal particles as a bonding material has been studied (see, for example, Patent Document 1). In Patent Document 1, a bonding material in which a film made of an organic substance is applied around a core made of metal particles having an average particle diameter of 100 nm or less is bonded by heating to decompose the organic substance to sinter the metal particles. It is described to do. In this bonding method, the metal particles after bonding change into a bulk metal and at the same time are bonded by metal bonding at the bonding interface, so that they have very high heat resistance, reliability, and high heat dissipation. In addition, in connection of electronic parts and the like, lead-free soldering is required, but there is no substitute material for high-temperature solder. Since the use of hierarchical solder is indispensable for mounting, the appearance of a material that replaces this high-temperature solder is desired. Therefore, this joining technique is also expected as a material to replace this high temperature solder.

JP 2004-107728 A

When the present inventors examined about the joining material which used the metal particle of the average particle diameter of 100 nm or less as described in patent document 1 etc. as a main agent of joining, as a to-be-joined member, with respect to the other electrodes, such as Au, Ag, Pd However, it was found that sufficient bonding strength could not be obtained for Cu and Ni, which are often applied in semiconductor mounting. FIG. 8 shows the results of evaluation of bonding strength performed on each electrode material. Using a silver particle having an average particle diameter of 10 nm coated with an amine-based organic material as a bonding material with a bonding temperature of 250 ° C. and a pressure of 1.0 MPa constant, to an Au, Ag, Pd, Ni, and Cu electrode in the atmosphere. Were joined. The vertical axis in FIG. 8 indicates the shear strength and is normalized by the value of the Ag electrode. As a result, Au,
It was found that good bonding strength was obtained for Ag and Pd electrodes, but sufficient bonding strength was not obtained for Ni and Cu electrodes.

  The organic material coated with the ultrafine particles described in Patent Document 1 is a material that disappears only by heating in the atmosphere, and is effective for electrodes that are difficult to oxidize. Not suitable.

  In the case where electronic components constituting a semiconductor device are bonded using a bonding material containing metal ultrafine particles as a main agent for bonding, it is necessary to ensure electrical continuity. The bonding material is also required to relax thermal strain and to have thermal conductivity. Furthermore, it must be able to join even the most frequently used Ni and Cu electrodes.

  An object of this invention is to improve the joining reliability of the junction part of Ni or Cu electrode of a semiconductor device, and the joining material which uses a metal particle as the main ingredient of joining.

  As a result of sincerity studies by the present inventors in order to solve the above-mentioned problems, reduction is achieved by a bonding material containing metal oxide particles having an average particle diameter of 1 nm to 50 μm, which is a metal particle precursor, and a reducing agent made of an organic substance. It has been found that excellent bonding strength with respect to Ni or Cu electrodes can be obtained by bonding in an atmosphere.

  The present invention is a semiconductor device in which a semiconductor element and a Cu or Ni electrode are connected via a bonding layer made of Ag, Cu or Au, and the bonding layer and the Cu or Ni electrode are bonded by mutual diffusion bonding. A semiconductor device having the above structure is characterized.

  A method of manufacturing a semiconductor device in which an electrode of a semiconductor element and a wiring for extracting an electrical signal of the semiconductor element to the outside are joined, wherein at least one of the electrode of the semiconductor element or the wiring is Cu or A semiconductor device comprising a step of bonding the electrode and the wiring by heating in a reducing atmosphere with a bonding material comprising metal oxide particles made of Ni and having an average particle diameter of 1 nm to 50 μm and a reducing agent made of an organic substance. The manufacturing method is characterized.

  According to the present invention, it is possible to improve the bonding reliability of a bonding portion between a Ni or Cu electrode of a semiconductor device and a bonding material using metal particles as a main bonding agent.

  Hereinafter, the present invention will be described in detail. It has been found that, in the conventional bonding using a bonding material having metal particles having an average particle size of 100 nm or less as the main agent for bonding, an oxide layer is formed on the surface of the Ni or Cu electrode at the time of bonding. This oxide layer is considered to be a factor for reducing the bonding strength. On the other hand, as a result of sincerity studies by the present inventors, it has been found that excellent bonding strength can be obtained even for Ni or Cu electrodes by performing bonding in a reducing atmosphere using a specific bonding material. It was. That is, by bonding in a reducing atmosphere with a bonding material containing metal oxide particles having an average particle diameter of 1 nm to 50 μm, which is a metal particle precursor, and a reducing agent made of an organic substance, a Ni or Cu electrode can be bonded. Excellent bonding strength can be obtained. In this bonding, by adding a reducing agent made of an organic substance to the metal particle precursor, the metal particle precursor is reduced at a lower temperature than when the metal particle precursor alone is thermally decomposed. A phenomenon is used in which metal particles of 100 nm or less are produced and the metal particles are joined together by fusing each other. In the presence of a reducing agent, metal oxide particles begin to be produced at a temperature of 200 ° C. or less and 100 nm or less. Therefore, bonding can be achieved even at a low temperature of 200 ° C. or less, which has been difficult in the past. In addition, since metal particles having a particle size of 100 nm or less are created in-situ during bonding, it is not necessary to prepare metal particles whose surfaces are protected by organic substances, manufacturing of bonding materials, simplification of bonding processes, bonding A significant cost reduction of the material can be achieved. Further, the formation of an oxide layer of the Ni or Cu electrode is suppressed by the bonding in a reducing atmosphere and the reducing action of the reducing agent, and a strong metal bond between the Ni or Cu electrode and the metal particles can be achieved.

  The metal particle precursor having an average particle diameter of 1 nm to 50 μm for producing metal particles of 100 nm or less is defined as a metal oxide because the metal content in the metal particle precursor is high, so that the volume shrinkage during bonding This is because the oxidative decomposition of the organic matter is promoted because it is small and generates oxygen during decomposition. Here, the metal particle precursor refers to a substance that produces metal particles having a particle size of 100 nm or less after being mixed with a reducing agent and reduced by heating.

  The reason why the average particle size of the metal particle precursor used here is 1 nm or more and 50 μm or less is that when the average particle size of the metal particles is larger than 50 μm, it is difficult to produce metal particles having a particle size of 100 nm or less during bonding. This increases the number of gaps between particles, making it difficult to obtain a dense bonding layer. The reason why the thickness is 1 nm or more is that it is difficult to actually produce a metal particle precursor having an average particle size of 1 nm or less. In the present invention, since metal particles having a particle size of 100 nm or less are produced during bonding, the particle size of the metal particle precursor does not have to be 100 nm or less, and the metal particle precursor is produced, handled, and stored for a long period of time. From this viewpoint, it is preferable to use particles having a particle diameter of 1 to 50 μm. In order to obtain a denser bonding layer, it is also possible to use a metal particle precursor having a particle size of 1 nm to 100 nm.

Examples of the metal oxide particles include silver oxide (Ag ₂ O, AgO), copper oxide, gold oxide, and the like, and a bonding material made of at least one metal or two or more metals from these groups is used. Is possible. Since metal oxide particles composed of gold oxide, silver oxide (Ag ₂ O, AgO), and copper oxide generate only oxygen during reduction, residues after bonding are hardly left and the volume reduction rate is very small.

  As content of a metal particle precursor, it is preferable to set it as 99 mass parts or less exceeding 50 mass parts in the total mass part in a joining material. This is because when the metal content in the bonding material is high, the organic residue is reduced after bonding at low temperature, and it becomes possible to achieve a dense fired layer at low temperature and to achieve metal bonding at the bonding interface. This is because it becomes possible to obtain a bonding layer having improved heat dissipation and high heat resistance.

  As the reducing agent composed of an organic substance, one or more mixtures selected from alcohols, carboxylic acids, and amines can be used.

  Examples of the compound containing an alcohol group that can be used include alkyl alcohols such as ethanol, propanol, butyl alcohol, pentyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, and dodecyl. There are alcohol, tridecyl alcohol, tetradecyl alcohol, pentadecyl alcohol, hexadecyl alcohol, heptadecyl alcohol, octadecyl alcohol, nonadecyl alcohol, icosyl alcohol. Furthermore, not only the primary alcohol type, but also an alcohol compound having a secondary alcohol type such as ethylene glycol or triethylene glycol, a tertiary alcohol type, alkanediol, or a cyclic type structure can be used. In addition, compounds having four alcohol groups such as citric acid and ascorbic acid may be used.

  Moreover, there exists alkylcarboxylic acid as a compound containing carboxylic acid which can be utilized. Specific examples include butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, Examples include octadecanoic acid, nonadecanoic acid, and icosanoic acid. Further, similarly to the amino group, it is possible to use not only the primary carboxylic acid type but also a secondary carboxylic acid type, tertiary carboxylic acid type, dicarboxylic acid, and a carboxyl compound having a cyclic structure.

  Moreover, an alkylamine can be mentioned as a compound containing an available amino group. For example, butylamine, pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, octadecylamine, There are nonadecylamine and icodecylamine. The compound having an amino group may have a branched structure, and examples thereof include 2-ethylhexylamine and 1,5-dimethylhexylamine. In addition to the primary amine type, a secondary amine type or a tertiary amine type can also be used. Further, such an organic material may have an annular shape.

  The reducing agent to be used is not limited to the organic substance containing the alcohol, carboxylic acid, and amine, but may be an organic substance containing an aldehyde group, an ester group, a sulfanyl group, or a ketone group.

Here, reducing agents that are liquid at 20 to 30 ° C., such as ethylene glycol and triethylene glycol, are reduced to silver after one day if mixed with silver oxide (Ag ₂ O) and the like and left after mixing. Need to be used immediately. On the other hand, myristyl alcohol, laurylamine, ascorbic acid, etc., which are solid in the temperature range of 20-30 ° C., do not react greatly with metal oxides for about a month, so they have excellent storage stability. These are preferably used when stored for a long time after mixing. Further, it is desirable that the reducing agent used has a certain number of carbon atoms in order to function as a protective film for purified metal particles having a particle size of 100 nm or less after reducing metal oxides and the like. Specifically, it is desirably 2 or more and 20 or less. This is because, when the number of carbon atoms is less than 2, metal particles are produced at the same time as particle size growth occurs, making it difficult to produce metal particles of 100 nm or less. On the other hand, if it exceeds 20, the decomposition temperature becomes high and the metal particles are hardly sintered, resulting in a decrease in bonding strength.

  The amount of the reducing agent used may be in the range of 1 part by mass to 50 parts by mass with respect to the total weight of the metal particle precursor. This is because if the amount of the reducing agent is less than 1 part by mass, the amount of the metal particle precursor in the bonding material is not reduced enough to produce metal particles. Moreover, when it exceeds 50 mass parts, it is because the residue after joining increases and it is difficult to achieve metal joining at the interface and densification in the joining silver layer. Furthermore, as a reducing agent, it is preferable that the thermal weight reduction rate at the time of a heating to 400 degreeC is 99% or more. This is because if the decomposition temperature of the reducing agent is high, the residue after bonding increases, and it is difficult to achieve metal bonding at the interface and densification in the bonding silver layer. Here, the measurement of the thermogravimetric decrease rate at the time of heating up to 400 ° C. is performed using a commercially available apparatus such as TG / DTA6200 manufactured by Seiko Instruments or TGA-50 manufactured by Shimadzu Corporation. It shall be when conducted in air at 10 ° C / min.

  The combination of the metal particle precursor and the reducing agent composed of an organic substance is not particularly limited as long as the metal particles can be produced by mixing them, but from the viewpoint of storage stability as a bonding material, the metal is used at room temperature. A combination that does not produce particles is preferred.

  Moreover, it is also possible to mix and use metal particles having a relatively large average particle diameter of 50 μm to 100 μm in the bonding material. This is because the metal particles of 100 nm or less produced during bonding play a role of sintering metal particles having an average particle diameter of 50 μm to 100 μm. Further, metal particles having a particle size of 100 nm or less may be mixed in advance. Examples of the metal particles include gold, silver, and copper. In addition to the above, at least one metal selected from platinum, palladium, rhodium, osmium, ruthenium, iridium, iron, tin, zinc, cobalt, nickel, chromium, titanium, tantalum, tungsten, indium, silicon, aluminum, etc. It is possible to use an alloy made of more than one kind of metal.

  The bonding material used in this embodiment may be used only with a reducing agent comprising a metal particle precursor and an organic substance, but a solvent may be added when used as a paste. If it is used immediately after mixing, it may be used with a reducing action such as methanol, ethanol, propanol, ethylene glycol, triethylene glycol, terpineol alcohol, etc. It is preferable to use water, hexane, tetrahydrofuran, toluene, cyclohexane, or the like having a weak reducing action at room temperature. In addition, when a reducing agent such as myristyl alcohol that is difficult to reduce at room temperature is used, it can be stored for a long time, but when a reducing agent such as ethylene glycol is used, it is mixed at the time of use. And preferably used.

Moreover, in order to improve the dispersibility of the metal particle precursor in the solvent, the periphery of the metal particle precursor may be coated with an organic substance using a dispersant as necessary to improve the dispersibility. Examples of the dispersant used in the present invention include polyvinyl alcohol, polyacrylonitrile, polyvinyl pyrrolidone, polyethylene glycol, and other commercially available dispersants such as Dispersic 160, Dispersic 161, Dispersic 162, Dispersic 163, and the like. Dispersic 166, Dispersic 170, Dispersic 180, Dispersic 182, Dispersic 184, Dispersic 190 (manufactured by Big Chemie), MegaFuck F-479 (Dainippon Ink), Solsperse 20000, Solsperse 24000, Solsperse 26000 , Solsperse 27000, Solsperse 28000 (above, manufactured by Abyssia) and the like can be used. The amount of such a dispersant used is in the range of 0.01 wt% or more and not exceeding 45 wt% in the bonding material for the metal particle precursor.

  These paste materials can be applied using a method in which the paste is ejected from a fine nozzle by an ink jet method and applied to the electrode or the connection part of the electronic component on the substrate, or a metal mask or mesh mask with an open application part. A method of applying only to the surface, a method of applying to a necessary part using a dispenser, a water-repellent resin containing silicone, fluorine, etc., is applied with a metal mask or mesh mask having an opening only on the necessary part, or photosensitive. A method of applying a water-repellent resin on a substrate or electronic component, removing a portion to which the paste composed of the fine particles and the like is applied by exposure and development, and then applying a bonding paste to the opening, and After applying the water-repellent resin to the substrate or electronic component, the paste application part consisting of the metal particles is applied with a laser. Removed, there is then a method of applying a bonding paste in the opening. These coating methods can be combined according to the area and shape of the electrodes to be joined. In addition, when a solid material at room temperature such as myristyl alcohol or ascorbic acid is used as the reducing agent, there is a method of forming a sheet by mixing with a metal particle precursor and applying pressure to use as a bonding material .

  In bonding using this bonding material, metal particles having a particle size of 100 nm or less are produced from the metal particle precursor during bonding, and metal bonding is performed by fusing metal particles having a particle size of 100 nm or less while discharging organic substances in the bonding layer. It is essential to apply heat and pressure to do this. Further, in order to achieve mutual diffusion bonding with the Ni or Cu electrode, it is essential to perform bonding in a reducing atmosphere. As joining conditions, it is preferable to apply heating of 50 ° C. or more and 400 ° C. or less and pressurization of 0.01 to 10 MPa within 1 second or more and 10 minutes or less.

  In the bonding according to the present invention, the metal oxide particles become pure ultrafine metal particles that are not oxides having a particle size of about 0.1 to 50 nm by heating at the time of bonding, and the pure metal ultraparticles are fused together to become a bulk. . The melting temperature after becoming bulk is the same as the melting temperature of metals in the normal bulk state, and the ultrafine metal particles are melted by low-temperature heating, and after melting, they are heated to the melting temperature in the bulk state. It does not re-melt until This is because when pure metal ultrafine particles are used, bonding can be performed at a low temperature, and the melting temperature is improved after bonding. The advantage of not melting. Further, the thermal conductivity of the bonding layer after bonding can be 50 to 430 W / mK, and the heat dissipation is excellent. Further, since the precursor is a metal oxide, there is a merit of low cost. Note that it is necessary to coat the metal oxide particles with an organic substance such as alcohol in order to promote the reduction effect. Furthermore, the atmosphere during bonding needs to be a reducing atmosphere. As the reducing atmosphere, for example, hydrogen can be used.

  An oxide layer that inhibits metallic bonding is not formed at the interface bonded through the bonding material and the bonding method described above. The metal particles generated by reduction are required to be bonded to the mating member in a metallic manner by bonding to increase the bonding strength and to ensure electrical conduction. Of course, the mating member is also required to be metallically bonded to the metal forming the metal particles. For this reason, it is desirable that the mating member be formed of a material that is metal-bonded to the metal particles. In the counterpart member made of Ni, Cu, or an alloy containing them as a main component, the metal particles and the counterpart member are metallicly bonded at the time of joining. In addition, also in the case of silver oxide and copper oxide mixed, it has the advantage that it can join similarly to the above and can improve corrosion resistance.

  By using the bonding material and the bonding method described above for bonding Ni or Cu electrodes of a semiconductor device, it is possible to obtain excellent bonding reliability.

  Hereinafter, examples of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments.

  1A and 1B show an insulating semiconductor device to which the present invention is applied. FIG. 1A is a plan view and FIG. 1B is a cross-sectional view taken along line AA 'in FIG. FIG. 2 is a perspective view showing the main part of FIG.

  In this embodiment, one surface of the semiconductor element 101 has a collector electrode (not shown) formed on the ceramic insulating substrate 103 by a bonding layer 105 containing silver oxide particles (containing 5 wt% of myristyl alcohol and pure silver after bonding) 105. The wiring layer 102 is joined. The ceramic insulating substrate 103 is bonded to the support member 110 via the solder layer 109. The ceramic insulating substrate 103 and the wiring layer 102 are referred to as a wiring substrate. The wiring layer 102 is obtained by applying Ni plating to Cu wiring. The bonding layer 105 has a thickness of 80 μm. On the other surface of the semiconductor element 101, the emitter electrode is bonded to the connection terminal 201 using a bonding material using silver oxide particles (pure silver layer after bonding), and the connection terminal 201 is on the ceramic insulating substrate 103. The wiring layer 104 and the silver oxide particle using bonding material (pure silver layer after bonding) are used for bonding. 1 indicate the case 111, the external terminal 112, the bonding wire 113, and the sealing material 114, respectively.

FIG. 3 is an enlarged cross-sectional view of the semiconductor element mounting portion in FIG. The collector electrode 106 ′ of the semiconductor element 101 and the wiring layer 102 are bonded with a bonding material using silver oxide particles (pure silver layer after bonding). The wiring layer 102 is obtained by applying Ni plating to Cu wiring. The bonding material using silver oxide particles (pure silver layer after bonding) has the same structure at the bonding portion between the emitter electrode 106 of the semiconductor element and the connection terminal 201 and at the bonding portion between the connection terminal 201 and the wiring layer 104. Has been applied. Ni is applied to the surface of the collector electrode 106 ′ and the surface of the emitter electrode 106. The connection terminal 201 is made of Cu or Cu alloy. Each joint part using silver oxide particles may be performed individually or simultaneously. A joining material using silver oxide particles is placed between members to be joined, and heat at 250 ° C. is applied for about 1 minute in that state, and 1.0 at the same time.
Bonding can be performed by applying a pressure of MPa in 100% hydrogen. In joining, ultrasonic vibration can be applied.

  FIG. 4 shows the result of evaluation of the bonding strength performed on the bonded portion of the present invention. The bonding temperature was fixed at 250 ° C. and the pressure was fixed at 1.0 MPa, and the influence of the mating electrode and the heating atmosphere during bonding was investigated. The results are shown. In this evaluation, silver oxide particles having an average particle diameter of 2 μm containing 5 wt% myristyl alcohol were used as bonding materials and bonded to Ag, Ni, and Cu electrodes in air and in a reducing atmosphere, respectively. The vertical axis in FIG. 4 indicates the shear strength and is normalized by the value of the Ni electrode in hydrogen.

  As a result, it was found that, in bonding in the air, good bonding strength was obtained for the Ag electrode, but sufficient bonding strength was not obtained for the Ni and Cu electrodes. On the other hand, when bonded in a reducing atmosphere, the bonding strength to the Ni electrode and Cu electrode is the same as that bonded to the Ag electrode. Even strong bonding has been achieved. From this evaluation result, it was found that joining to Ni and Cu electrodes could not be achieved only by the reduction effect of silver oxide by myristyl alcohol.

  In addition, under the same bonding conditions, the bonding to the Cu electrode was evaluated in the air and in the reducing atmosphere using silver oxide particles not containing a reducing agent (myristyl alcohol) as a bonding material. As a result, as shown in FIG. 4, it can be seen that, although bonding strength is slightly increased by bonding in a reducing atmosphere as compared to the atmosphere, sufficient bonding strength cannot be obtained in both the air and the reducing atmosphere. It was. From this evaluation result, it was found that bonding to Ni and Cu electrodes cannot be achieved only by bonding in a reducing atmosphere.

  From the above results, bonding to Ni and Cu electrodes is possible by performing bonding in a reducing atmosphere using a bonding material containing oxide metal particles and a reducing agent.

  In addition, although only the Ag electrode was shown as an electrode other than the Ni and Cu electrodes, it was confirmed that good bonding can be performed to noble metals such as Au and Pt as well as the Ag electrode in bonding in the air. Yes.

  FIG. 5 is a view showing a state of a cross section of the joint in FIG. In the conventional method, an oxide layer is formed at the interface, and metallic bonding is hindered. On the other hand, in the method of the present invention, it has been found that there is nothing that inhibits bonding at the interface with respect to Ni and Cu, and that metallic bonding (interdiffusion bonding) can be achieved.

  Next, a preferred example of the semiconductor device according to the present embodiment will be described.

  The bonding layer 105 made of metal fine particles shown in FIG. 3 is a portion where current flows. For this reason, in addition to silver oxide, copper oxide is also an effective material for the material of the particle layer. Alternatively, a mixed material of silver oxide and copper oxide may be used. In these cases as well, the nano-sized particles produced are bonded to the mating electrode due to the reduction effect during heating (reduction action by an organic substance such as alcohol and a reducing atmosphere), and the bonding temperature at that time should be 200 ° C. or less. Can do. The thermal expansion coefficient of Cu or its alloy is about 8 to 16 ppm / ° C. Silicon nitride is preferably used for the ceramic insulating substrate 103. The thermal expansion coefficient of silicon nitride is about 9 ppm / ° C. In addition, it is desirable that the solder layer 109 be a bonding layer using an oxide in order to improve heat dissipation.

  In the power semiconductor module of this structure, since the semiconductor element 101 and the insulating wiring board having a thermal expansion coefficient of about 9 ppm / ° C. are bonded via a bonding material having a thermal expansion coefficient of 8 to 16 ppm / ° C. It is possible to reduce the thermal stress caused by the significant difference in thermal expansion of each member. Ideally, by matching the thermal expansion coefficient of the bonding material to that of the wiring board, the thermal stress generated in the bonding material is minimized, and long-term reliability is improved.

  The semiconductor device of the present invention can be applied to various power conversion devices. By applying the semiconductor device of the present invention to the power conversion device, long-term reliability can be ensured even if it can be mounted in a place of a high temperature environment and does not have a dedicated cooler.

  FIG. 6 is a diagram illustrating a circuit of a semiconductor device. There are two systems of blocks 910 in which four MOS FET elements 101 are arranged in parallel. Each block 910 is connected in series, and an input main terminal 30in, an output main terminal 30out, and an auxiliary terminal 31 are drawn from a predetermined portion. The main part of the semiconductor device 900 is configured. Further, the thermistor 34 for temperature detection during operation of this circuit is disposed independently in the semiconductor device 900.

  Further, the inverter device and the electric motor can be incorporated in the electric vehicle as a power source. In this car, the drive mechanism from the power source to the wheels has been simplified, so the shock at the time of shifting is reduced and smooth running is possible compared to the conventional car that has been shifting due to the difference in gear engagement ratio. Thus, vibration and noise can be reduced as compared with the conventional case. Note that the semiconductor device 900 of this embodiment can be incorporated in the inverter device for controlling the rotational speed of the hybrid vehicle electric motor 960 shown in FIG.

  Furthermore, the inverter device incorporating the semiconductor device 900 of this embodiment can be incorporated into an air conditioner. In this case, higher efficiency can be obtained than when a conventional AC motor is used. Thereby, the power consumption at the time of air-conditioning machine use can be reduced. Moreover, the time until the room temperature reaches the set temperature from the start of operation can be shortened compared to the case where the conventional AC motor is used.

  The same effect as that of the present embodiment can be enjoyed even when the semiconductor device 900 is incorporated in a device that stirs or flows another fluid, such as a washing machine or a fluid circulation device.

  In addition, the metal ultrafine particle specification bonding material of the present invention can also be applied to bonding at a portion where heat generation is large, such as an LED backlight.

(A) is a top view of the insulation type semiconductor device by the position example of this invention, (b) is AA sectional drawing. It is the perspective view which showed the principal part of FIG. It is sectional drawing which expanded and showed the semiconductor element mounting part in FIG. It is a figure which shows the joining property of the junction part by this invention. It is a figure which shows the state of the junction part by this invention. It is a circuit diagram of a semiconductor device. It is the schematic which shows the inverter apparatus for rotation speed control of a hybrid vehicle electric motor. It is a figure which shows the bondability of the junction part by silver fine particles.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Semiconductor element 102,104 Wiring layer 103 Ceramic insulation board | substrate 105 Joining layer 106 Emitter electrode 110 Support member 201 Connection terminal

Claims (11)

A semiconductor element;
A ceramic insulating substrate provided with a wiring layer on the surface,
The surface of the wiring layer is made of Ni,
A semiconductor device in which the electrode of the semiconductor element and the wiring layer are connected via a fired layer,
The fired layer is a layer made of Ag, Cu or Au,
The semiconductor device, wherein the fired layer and Ni on the surface of the wiring layer are directly metal-bonded to each other.   2. The semiconductor device according to claim 1, wherein the fired layer has a thermal conductivity of 50 to 430 W / mK. The semiconductor device according to claim 1,
An oxide layer is not present at the boundary between the fired layer and Ni on the surface of the wiring layer. A semiconductor element having a first electrode on one side and a second electrode on the other side;
A ceramic insulating substrate having a wiring layer on the surface;
A semiconductor device having one end connected to the second electrode of the semiconductor element and the other end connected to the wiring layer;
The surface of the wiring layer is made of Ni,
The wiring layer and the first electrode of the semiconductor element are bonded via a first fired layer,
The wiring layer and the other end of the connection terminal are joined via a second firing layer,
The first fired layer and the second fired layer are layers made of Ag, Cu or Au,
The first fired layer and Ni on the surface of the wiring layer are directly metal-bonded to each other, and the second fired layer and Ni on the surface of the wiring layer are directly metal-bonded to each other apparatus. The semiconductor device according to claim 4,
The connection terminal and the second electrode are joined via a third fired layer,
The surface of the second electrode is made of Ni,
The fired layer is a layer made of Ag, Cu or Au,
The semiconductor device, wherein the third fired layer and the connection terminal are directly metal-bonded to each other.   A power conversion device comprising the semiconductor device according to claim 4.   A hybrid vehicle, wherein the power conversion device according to claim 6 is mounted in an engine room. A method of manufacturing a semiconductor device bonded to an electrode of a semiconductor element and a wiring for supplying current to the semiconductor element
At least one of the electrodes of the semiconductor element or the wiring is made of Ni,
A step of bonding the electrode and the wiring by heating in a reducing atmosphere with a bonding material including metal oxide particles having an average particle diameter of 1 nm to 50 μm and a reducing agent made of an organic substance;
A method of manufacturing a semiconductor device, characterized in that, in the step, pressurization of 0.01 to 10 MPa and heating to 50 to 400 ° C. are applied. In the manufacturing method of the semiconductor device according to claim 8,
The method for manufacturing a semiconductor device, wherein the metal compound is a compound of gold, silver, or copper. In the manufacturing method of the semiconductor device in any one of Claim 8 or Claim 9,
A method of manufacturing a semiconductor device, wherein the reducing agent is one or a mixture of two or more selected from alcohols, carboxylic acids, and amines. In the manufacturing method of the semiconductor device in any one of Claims 8 thru / or 10 ,
A method of manufacturing a semiconductor device, wherein the metal particle precursor is reduced by the heating to refine metal particles having an average particle diameter of 100 nm or less.

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