JP6911804B2 - Manufacturing method of joint - Google Patents

Description

The present invention relates to a method for producing a bonded body.

When assembling or mounting electronic components such as semiconductor elements and LED (light emitting diode) elements, when joining two or more components, a bonding material is generally used. As such a bonding material, a silver paste in which silver particles are dispersed in an organic solvent is known. One component and the other component are laminated via this silver paste, the obtained laminate is heated, and the silver particles in the silver paste are sintered to form a bonding layer (silver particle sintered body). Parts can be joined by forming.

In order to improve the strength of the bonding layer and prevent corrosion of the bonding layer by a liquid (for example, water), it has been studied to fill the pores of the sintered body of silver particles, which is the bonding layer, with a resin. Patent Document 1 describes a paste-like metal particle composition composed of (A) heat-sinterable metal particles having an average particle size of 0.1 μm to 50 μm and (B) a volatile dispersion medium between a plurality of metal members. The volatile dispersion medium is volatilized by heating at 70 ° C. or higher and 400 ° C. or lower, the metal members are bonded to each other by a sintered metal particles, and then the curable liquid resin composition is made porous. A method for producing a bonded body which is impregnated in a quality sintered product and cured is disclosed.

JP-A-2010-65277

By the way, in power modules and high-brightness LEDs, the amount of heat generated by electronic components is increasing, and the bonding layer that joins these electronic components is fatigued by the on / off of electronic components and the cold heat cycle caused by the ambient temperature. High heat and fatigue resistance is required so that electronic components do not peel off. However, in the bonding layer in which the pores of the sintered body of silver particles are filled with resin, the resin repeatedly expands and contracts due to the cooling and heating cycle, so that the sintered body of silver particles is damaged and the heat resistance is deteriorated. In some cases, it was difficult to improve the heat resistance to the thermal cycle.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for producing a bonded body capable of obtaining a bonded body having improved heat and fatigue resistance to a cold heat cycle of the bonded layer.

In order to solve the above problems, the method for manufacturing a joined body of the present invention is a method for manufacturing a joined body in which a first member and a second member are joined, and the first member and the second member are used together. The silver paste layer has a particle size D50 of 50% by volume in a volume-based integrated particle size distribution under a sieve of 0.3 μm or more and 1.0 μm or less. Silver particles whose ratio D90 / D10 of 90% by volume particle size D90 to 10% by volume particle size D10 in the volume-based integrated particle size distribution under the sieve is in the range of 5.0 or more and 10 or less. In the step of obtaining a laminate containing A step of forming a porous silver sintered body layer having continuous pores within a range of 0.0 μm or less and a porosity of 20% or more, and applying a resin to the continuous pores of the porous silver sintered body layer. It is characterized by having a filling step.

According to the method for producing a bonded body of the present invention having such a configuration, the silver particles contained in the silver paste layer have a particle size D50 of 50% by volume in the volume-based integrated particle size distribution under a sieve of 0.3 μm or more. The ratio D90 / D10 of 90% by volume particle size D90 to 10% by volume particle size D10 in the volume-based integrated particle size distribution under a sieve, which is within the range of 1.0 μm or less and is relatively fine, is 5.0. Since the particle size distribution is within the range of 10 or less and the particle size distribution is wide, partial sintering is likely to occur even when heated at a relatively low temperature. Therefore, by heating the laminate having the silver paste layer, a strong necking structure is formed between the silver particles, and continuous pores having a pore diameter within the range of 0.5 μm or more and 3.0 μm or less are formed inside. It is possible to form a porous silver sintered body layer having a porosity of 20% or more. Then, by filling the continuous pores of the porous silver sintered body layer with the resin, a bonding layer having improved heat resistance to the thermal cycle can be formed between the first member and the second member.

Here, in the method for producing a bonded body of the present invention, it is preferable that the silver particles contain agglomerates of primary particles having an average particle size based on the number in the range of 0.020 μm or more and 0.10 μm or less.
In this case, fine silver particles (primary particles) having an average particle size based on the number of particles in the range of 0.020 μm or more and 0.10 μm or less are easily sintered, and can be heated between silver particles at a relatively low temperature. Since a strong necking structure can be formed, the heat and fatigue resistance of the bonding layer to the cooling and heating cycle is further improved.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a method for producing a bonded body capable of obtaining a bonded body having improved heat and fatigue resistance to the thermal cycle of the bonded layer.

It is sectional drawing of the joined body which concerns on one Embodiment of this invention. It is a flow figure explaining the manufacturing method of the bonded body which concerns on one Embodiment of this invention. It is an SEM (scanning electron microscope) photograph of the cross section of the joint layer of the joint body produced in Example 1 of the present invention.

Hereinafter, an embodiment of the present invention will be described with reference to the attached drawings.
FIG. 1 is a cross-sectional view of a joined body according to an embodiment of the present invention.
As shown in FIG. 1, the joined body 10 includes a first member 11 and a second member 12 joined to one surface (lower surface in FIG. 1) of the first member via a joining layer 20. There is.

As the first member 11, for example, a power semiconductor chip or an LED element is used. Further, as the second member 12, for example, a circuit board is used.

The bonding layer 20 fills the continuous pores of the porous silver sintered body layer 21 having continuous pores having a pore diameter within the range of 0.5 μm or more and 3.0 μm or less, and the porous silver sintered body layer 21. The resin 22 is included.

The porous silver sintered body layer 21 is a sintered body in which silver particles are partially sintered. A strong necking structure is formed between the silver particles by partially sintering the silver particles, and continuous pores are formed by three-dimensionally bonding the silver particles. By three-dimensionally bonding silver particles having excellent conductivity and thermal conductivity, a bonding layer 20 having high conductivity and thermal conductivity can be obtained.

The resin 22 is three-dimensionally filled in the continuous pores of the porous silver sintered body layer 21. Since the continuous pores have a pore diameter of 0.5 μm or more, it is easy to fill the resin 22. By three-dimensionally filling the resin 22, the thermal stress applied to the porous silver sintered body layer 21 in a high temperature environment is relaxed, and the heat and fatigue resistance of the bonding layer 20 to the cold heat cycle is improved. Further, since the pore diameter of the continuous pores is 3.0 μm or less, the porous silver sintered body layer 21 is unlikely to be damaged even if the resin 22 is repeatedly expanded and contracted by the cooling / heating cycle.

The content of the resin 22 in the bonding layer 20 is preferably 20% by volume or more. If the content of the resin 22 is less than 20% by volume, the effect of relaxing the thermal stress by the resin 22 is reduced, and the heat resistance to the thermal cycle of the bonding layer 20 may be reduced. On the other hand, if the content of the resin 22 is too large, the distance between the silver particles becomes too wide, and the conductivity and thermal conductivity may decrease. Therefore, the content of the resin 22 in the bonding layer 20 is preferably 50% by volume or less.

The resin 22 is preferably a cured product of a curable resin. As the curable resin, for example, an epoxy resin, a phenol resin, a polyurethane resin, an alkyd resin, a polyester resin, a silicone resin, a polyamide-imide resin, or a polyimide resin can be used.

Next, a method of manufacturing the bonded body 10 according to the present embodiment will be described.
FIG. 2 is a flow chart illustrating a method for manufacturing a bonded body according to an embodiment of the present invention.
As shown in FIG. 2, the method for manufacturing the bonded body 10 of the present embodiment includes a laminated body manufacturing step S01, a porous silver sintered body layer forming step S02, and a resin filling step S03.

(Laminate body manufacturing step S01)
In the laminate manufacturing step S01, a laminate in which the first member 11 and the second member 12 are laminated via a silver paste layer is produced. In the laminate, for example, silver paste is applied to one of the first member 11 or the second member to form a silver paste layer, and then the second member 12 or the first member 11 is arranged on the silver paste layer. The method can be obtained by applying a silver paste to both the first member 11 and the second member 12 to form a silver paste layer, and then superimposing the silver paste layers on top of each other.

The silver paste is a paste-like composition containing a solvent and silver particles.
The solvent of the silver paste is not particularly limited as long as it can be removed by evaporation in the porous silver sintered body layer forming step S02 described later. As the solvent, for example, an alcohol solvent, a glycol solvent, an acetate solvent, a hydrocarbon solvent, or an amine solvent can be used. Examples of alcohol-based solvents include α-terpineol and isopropyl alcohol. Examples of glycol-based solvents include ethylene glycol, diethylene glycol, and polyethylene glycol. Examples of acetate-based solvents include butyl toll carbitate acetate. Examples of hydrocarbon solvents include decane, dodecane, and tetradecane. Examples of amine-based solvents include hexylamine, octylamine, and dodecylamine. One of these solvents may be used alone, or two or more of these solvents may be used in combination.

The silver particles have a particle size D50 of 50% by volume in the volume-based integrated particle size distribution under the sieve within the range of 0.3 μm or more and 1.0 μm or less, and 10% by volume in the volume-based integrated particle size distribution under the sieve. The ratio D90 / D10 of the particle size D90 of 90% by volume to the diameter D10 is in the range of 5.0 or more and 10 or less. The silver particles having such a particle size distribution are a mixture of fine silver particles that are easy to sinter at a relatively low temperature and coarse silver particles that are difficult to sinter at a relatively low temperature. When heated at a relatively low temperature of ° C. or higher and 300 ° C. or lower, coarse silver particles can be partially sintered via fine silver particles. By partial sintering of the silver particles, a strong necking structure is formed between the silver particles, the pore diameter is in the range of 0.5 μm or more and 3.0 μm or less, and the porosity is 20% or more. A silver sintered body layer can be formed. The volume-based integrated particle size distribution under the sieve can be measured by a laser diffraction method.

If the particle size D50 of 50% by volume in the volume-based integrated particle size distribution under the sieve of silver particles is less than 0.3 μm, the pore size of the porous silver sintered body layer obtained by sintering may become too small. .. On the other hand, when the particle size D50 of 50% by volume in the volume-based integrated particle size distribution under sieving of silver particles exceeds 1.0 μm, tightly aggregated coarse agglomerated particles are formed, which makes it difficult for the silver particles to be sintered. Further, the porous silver sintered body layer obtained by sintering may have a non-uniform pore diameter and may become too large.

Further, if the ratio D90 / D10 of the particle size D90 of 90% by volume to the particle size D10 of 10% by volume in the volume-based integrated particle size distribution under the sieve is less than 5.0, and the width of the particle size distribution of silver particles becomes too narrow. , The distance between the silver particles becomes narrow, and the pore diameter of the porous silver sintered body layer obtained by heating may become too small. On the other hand, if the ratio D90 / D10 of 90% by volume particle size D90 to 10% by volume particle size D10 in the volume-based integrated particle size distribution under the sieve exceeds 10, and the width of the particle size distribution of silver particles becomes too wide. When fine silver particles enter the voids of the coarse silver particles, the distance between the silver particles becomes narrow, and the pore diameter of the porous silver sintered body layer obtained by heating may become too small.

The particle size D10 of 10% by volume in the volume-based integrated particle size distribution under the sieve of silver particles is preferably 0.3 μm or less. By containing 10% by volume or more of fine particles having a particle size of 0.3 μm or less, these fine particles can be filled in the gaps between particles having a relatively large particle size, so that a bonding layer having a uniform pore size is formed. can. Further, the particle size D90 of 90% by volume in the volume-based integrated particle size distribution under the sieve of silver particles is preferably 1 μm or more. Since coarse silver particles having a particle size of 1 μm or more are difficult to sinter, by containing 10% by volume or more of these coarse silver particles, a porous silver sintered body layer in which the silver particles are partially sintered is formed. It will be easier.

The silver particles preferably contain agglomerates of primary particles having an average particle size based on the number in the range of 0.020 μm or more and 0.10 μm or less. That is, the above D10, D50, and D90 are preferably the particle diameters of the aggregates (secondary particles) of the primary particles. The average particle size based on the number is determined by observing silver particles using a scanning electron microscope (SEM) and measuring the projected area of 100 silver particles whose overall shape has been confirmed. It is a value obtained by calculating the equivalent diameter (the diameter of a circle having the same area as the projected area of silver particles) and calculating the average thereof. Since the sintering temperature of the primary particles in which the average particle size based on the number is in the range of 0.020 μm or more and 0.10 μm or less is lower, the aggregates (secondary particles) of the primary particles are partially. Sintering is likely to occur.

The content of silver particles in the silver paste is preferably in the range of 70% by mass or more and 95% by mass or less. If it is less than 70% by mass, the amount of the solvent is relatively large, so that the sintering of silver particles is difficult to proceed in the porous silver sintered body layer forming step S02 described later, and the viscosity of the silver paste is low. If it becomes too large, it may be difficult to adjust the thickness of the silver paste layer, and it may be difficult to increase the thickness of the bonding layer 20. On the other hand, if the content of the silver particles exceeds 95% by mass, the viscosity of the silver paste becomes too high, and it may be difficult to form the silver paste layer.

(Porous Silver Sintered Body Layer Forming Step S02)
In the porous silver sintered body layer forming step S02, the laminate obtained in the above-mentioned laminate manufacturing step S01 is heated to remove the solvent of the silver paste layer and the silver particles are partially sintered. A porous silver sintered body layer having continuous pores having a pore diameter in the range of 0.5 μm or more and 3 μm or less and a porosity of 20% or more is formed inside.

The pore diameter (pore diameter) of the porous silver sintered body layer is a value calculated by using the BJH method from the adsorption curve of the adsorption isotherm of nitrogen gas. The BJH (Barrett, Joiner, Hallender) method is a method of calculating the pore diameter assuming that the pores are cylindrical.

For the porosity of the porous silver sintered body layer, a part of the porous silver sintered body layer was sampled as a sample, and the mass (g) and volume (cm ³ ) of this sample and the silver density (10.49 g /). It is a value calculated from cm ^{3) by the following formula.} The volume of the sample was determined from the length, width and thickness of the sample.
Porosity (%) = {1-sample mass / (sample volume x silver density)} x 100

The fact that the porous silver sintered body layer has continuous pores can be confirmed by observing the cross section of the porous silver sintered body layer using SEM.

The heating temperature of the laminate is, for example, in the range of 150 ° C. or higher and 300 ° C. or lower, preferably 170 ° C. or higher and 270 ° C. or lower. If the heating temperature is less than 150 ° C., the silver particles in the silver paste layer are difficult to sinter, and the porous silver sintered body layer may not be formed. On the other hand, if the heating temperature exceeds 300 ° C., the sintering of silver particles in the silver paste layer proceeds excessively, and the porosity of the formed porous silver sintered body layer may become too low.

The heating of the laminated body may be performed while applying pressure in the laminating direction of the laminated body. The stacking direction is a direction in which the first member 11 and the second member 12 are perpendicular to the surface in contact with the silver paste layer. By applying pressure in the laminating direction of the laminated body, the bonding force between the generated porous silver sintered body layer and the first member and the second member is increased, and the heat and fatigue resistance of the obtained bonded body to the cold heat cycle is increased. improves. When applying pressure in the stacking direction of the laminated body, the pressure is preferably in the range of 1 MPa or more and 10 MPa or less.

(Resin filling step S03)
In the resin filling step S03, the resin is filled into the continuous pores of the porous silver sintered body layer formed in the above-mentioned porous silver sintered body layer forming step S02. As a method of filling the continuous pores of the porous silver sintered body layer with the resin, an uncured product of the curable resin is injected into the continuous pores of the porous silver sintered body layer, and then the uncured product of the curable resin is injected. A method of curing can be used. The method of injecting the uncured product of the curable resin into the continuous pores is not particularly limited, and for example, a transfer molding method can be used.

According to the method for producing the bonded body 10 of the present embodiment having the above configuration, the silver particles contained in the silver paste layer have a particle size D50 of 50% by volume in the volume-based integrated particle size distribution under a sieve. The ratio D90 / D10 of the particle size D90 of 90% by volume to the particle size D10 of 10% by volume in the volume-based integrated particle size distribution under the sieve, which is within the range of 3 μm or more and 1.0 μm or less, is relatively fine. Since the particle size distribution is in the range of 2.0 or more and 5.0 or less and the particle size distribution is wide, partial sintering is likely to occur even when heated at a relatively low temperature. Therefore, by heating the laminate having the silver paste layer, a strong necking structure is formed between the silver particles, and continuous pores having a pore diameter in the range of 0.5 μm or more and 3 μm or less are provided inside. However, it is possible to form the porous silver sintered body layer 21 having a porosity of 20% or more. Then, by filling the continuous pores of the porous silver sintered body layer 21 with the resin 22, a bonding layer 20 having improved heat resistance to a thermal cycle is formed between the first member 11 and the second member 12. can do.

Further, in the method for producing a bonded body of the present embodiment, the silver particles contain agglomerates of primary particles having an average particle diameter of 0.020 μm or more and 0.10 μm or less based on the number of silver particles. Since a stronger necking structure can be formed between the silver particles by heating at a low temperature, the heat and fatigue resistance of the bonding layer to the cold heat cycle is further improved.

Although the embodiments of the present invention have been described above, the present invention is not limited to this, and can be appropriately changed without departing from the technical idea of the invention.

Next, the action and effect of the present invention will be described with reference to Examples.

[Examples 1 to 8 of the present invention, Comparative Examples 1 to 6]
(Silver particles)
Silver particles having a volume-based particle size (D10, D50, D90, D90 / D10) shown in Table 1 below and a number-based average particle size were prepared.
For the volume-based particle size, the volume-based integrated particle size distribution under the sieve of silver particles is measured by a laser diffraction method, and D10, D50, and D90 are read from the obtained integrated particle size distribution under the sieve to calculate D90 / D10. did. The average particle size based on the number is obtained by observing silver particles using SEM, measuring the projected area of 100 silver particles whose overall shape has been confirmed, and calculating the equivalent circle diameter from the obtained projected area. It was calculated and the average was calculated.

(Preparation of silver paste)
The prepared silver particles and ethylene glycol were mixed at a mass ratio of 85:15. The obtained mixture was kneaded using a kneader to prepare a silver paste.

(Laminate body manufacturing step S01)
A silicon wafer (size: 0.5 cm × 0.5 cm × 0.03 cm) was prepared as the first member, and a copper substrate (size: 2 cm × 2 cm × 0.5 cm) was prepared as the second member.
The silver paste prepared as described above was applied to the surface of the second member by a metal mask printing method to form a silver paste layer (0.5 cm × 0.5 cm × 50 μm). Next, the first member was arranged on the silver paste layer, and the first member and the second member were laminated via the silver paste layer to prepare a laminated body.

(Porous Silver Sintered Body Layer Forming Step S02)
The laminate produced in the laminate preparation step S01 is heated for 60 minutes at the temperature shown in Table 1 below and while applying the pressure shown in Table 1 below in the lamination direction to partially remove the silver particles of the silver paste layer. To form a porous silver sintered body layer. The porosity and pore diameter of the porous silver sintered body layer were measured by the above-mentioned method. The results are shown in Table 1 below. In Comparative Example 2, since the silver particles were not sintered, the porous silver sintered body layer could not be formed.

(Resin filling step S03)
The continuous pores of the porous silver sintered body layer formed in the porous silver sintered body layer forming step S02 were filled with an uncured product of the curable resin shown in Table 1 below by a transfer molding method. Next, the uncured product of the curable resin filled in the continuous pores was cured to obtain a bonded body.

[evaluation]

In Examples 1 to 8 of the present invention and Comparative Examples 1 to 3 to 6, the pore diameter and porosity of the porous silver sintered body layer before filling with the resin were measured in the resin filling step S03. The results are shown in Table 1 below. The pore diameter and porosity were measured by the above-mentioned method.

With respect to the bonded bodies prepared in Examples 1 to 8 of the present invention and Comparative Examples 1 and 3 to 6, the bonding ratio before and after applying the thermal cycle under the following conditions was measured by the following method. The results are shown in Table 1 below.

(Cold heat cycle conditions)
A cold cycle is performed in which the temperature of the conjugate is raised to 200 ° C. by the liquid phase method, held at that temperature for 15 minutes, then lowered from 200 ° C. to −40 ° C., and held at that temperature for 15 minutes. One cycle was used, and 1000 cycles were loaded.

(Joining rate)
The bonding ratio is determined by measuring the area (peeling area) of the portion where the bonding layer and the first member or the second member are separated using an ultrasonic flaw detector (IS-350, manufactured by Insight Co., Ltd.). , Calculated from the following formula.
In the image obtained by binarizing the ultrasonic flaw detection image of the joint layer taken by using the ultrasonic flaw detector, the peeled portion is shown as a white portion, so the area of this white portion was measured as the peeled area. The initial joining area is the area where the first member and the second member should be joined, that is, the area of the first member (0.5 cm × 0.5 cm).
Bonding rate (%) = {1- (peeling area / initial bonding area)} x 100

The bonded bodies obtained in Comparative Examples 1 and 3 to 6 had a low bonding ratio after the thermal cycle, and had insufficient heat fatigue resistance to the thermal cycle. Further, in Comparative Example 4, the bonding rate before the thermal cycle was also low.
In Comparative Example 1 in which silver particles having D50 and D90 / D10 smaller than the range of the present invention were used, since the raw material silver particles contained many fine particles, the silver particles were found in the porous silver sintered body layer forming step S02. It is considered that this is because the sintering progressed, the pore diameter of the porous silver sintered body layer became smaller than the range of the present invention, and the pores could not be sufficiently filled with the resin.
On the other hand, in Comparative Example 2 using silver particles in which D50 and D90 / D10 were larger than the range of the present invention, the porous silver sintered body layer could not be formed. It is considered that this is because the silver particles of the raw material are coarse and have low sinterability, so that the silver particles are less likely to be sintered at 150 ° C.

Although D50 is within the scope of the present invention, in Comparative Example 3 in which silver particles having D90 / D10 smaller than the scope of the present invention were used, porous silver was obtained by sintering fine silver particles having a narrow particle size distribution. It is considered that this is because the pore diameter of the porous silver sintered body layer obtained in the sintered body layer forming step S02 became smaller than the range of the present invention, and the pores could not be sufficiently filled with the resin.
Further, although D90 / D10 are within the range of the present invention, in Comparative Example 4 in which silver particles having D50 larger than the range of the present invention are used, the raw material silver particles are coarse and have low sinterability, so that the particles are interleaved with each other. A porous silver sintered body layer having high bonding strength was not formed. It is considered that the reason why the bonding rate after the thermal cycle was low was that the porous silver sintered body layer having low bonding strength between the particles was damaged due to the expansion and contraction of the resin due to the thermal cycle.

In Comparative Example 5 using silver particles in which D50 is larger than the range of the present invention and D90 / D10 is smaller than the range of the present invention, porous silver is obtained by sintering coarse silver particles having a narrow particle size distribution. The pore diameter of the porous silver sintered body layer obtained in the sintered body layer forming step S02 became larger than the range of the present invention, and the porous silver sintered body layer was damaged by the expansion and contraction of the resin due to the cooling and heating cycle. Is considered to be.
Although D50 is within the range of the present invention, in Comparative Example 6 in which silver particles having D90 / D10 smaller than the range of the present invention were used and the sintering temperature was 350 ° C., silver was used in the porous silver sintered body layer forming step S02. It is considered that this is because the sintering of the particles has progressed, the porosity of the porous silver sintered body layer has decreased, and the content of the resin filled in the porous silver sintered body layer has decreased.

On the other hand, Examples 1 to 1 of the present invention in which silver particles having D50 and D90 / D10 within the range of the present invention were used to form a porous silver sintered body layer having a pore diameter and a porosity within the range of the present invention. It was confirmed that the bonded body obtained in No. 8 had a high bonding rate after the thermal cycle and improved heat and fatigue resistance to the thermal cycle. In particular, the conjugates obtained in Examples 1 to 6 of the present invention using silver particles containing agglomerates of primary particles having an average particle size based on the number of particles in the range of 0.020 μm or more and 0.10 μm or less are subjected to a cold cycle. It was confirmed that the later bonding rate was high and the heat and fatigue resistance to the thermal cycle was further improved.

With the bonded body obtained in Example 1 of the present invention embedded in resin, the cross section was polished to expose the bonded layer. The cross section of the exposed and bonded layer was observed using SEM. The SEM photograph is shown in FIG. As is clear from the SEM photograph of FIG. 3, the bonding layer of the bonded body obtained in Example 1 of the present invention is a porous silver sintered body having continuous pores formed by three-dimensionally bonding silver particles. It was confirmed that the layer and the resin filled in the continuous pores were contained.

10 Joined body 11 1st member 12 2nd member 20 Joined layer 21 Porous silver sintered body layer 22 Resin

Claims (2)

A method for manufacturing a joined body in which a first member and a second member are joined.
It is a laminate in which the first member and the second member are laminated via a silver paste layer, and the silver paste layer is a particle size of 50% by volume in a volume-based integrated sieving particle size distribution with a solvent. When D50 is in the range of 0.3 μm or more and 1.0 μm or less, the ratio D90 / D10 of 90% by volume particle size D90 to 10% by volume particle size D10 in the volume-based integrated particle size distribution under the sieve is 5.0. A step of obtaining a laminate containing silver particles in the range of 10 or less, and
The laminate is heated to remove the solvent of the silver paste layer and the silver particles are partially sintered, so that continuous pores having a pore diameter in the range of 0.5 μm or more and 3.0 μm or less are inside. And a step of forming a porous silver sintered body layer having a porosity of 20% or more.
A step of filling the continuous pores of the porous silver sintered body layer with a resin, and
A method for producing a bonded body, which comprises. The method for producing a bonded body according to claim 1, wherein the silver particles contain an aggregate of primary particles having an average particle size based on the number of particles in the range of 0.020 μm or more and 0.10 μm or less.

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