JP2018001707A - Composite comprising thermosetting resin layer, metallic component, and silane coupling agent layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite which can suppress peeling of a thermosetting resin layer from a metallic component and can be produced more efficiently.SOLUTION: Provided is a composite comprising a thermosetting resin layer, a metallic component, and a silane coupling agent layer for connecting the thermosetting resin layer and the metallic component. When a pH value of extraction water of the thermosetting resin layer is denoted by N, and a thickness and a density of the thermosetting resin layer are denoted by t (mm) and d (g/cm), respectively, the silane coupling agent layer contains amino groups in a surface density of 5×10×t/d(mol/mm) or more.SELECTED DRAWING: Figure 2

Description

  The technology disclosed in this specification relates to a composite having a thermosetting resin layer, a metal member, and a silane coupling agent layer.

  Patent Document 1 discloses a composite (electronic component) having a thermosetting resin layer, a metal member, and a silane coupling agent layer. The silane coupling agent layer connects the thermosetting resin layer and the metal member. In this composite, an intermediate layer made of a metal oxide or the like is provided between the silane coupling agent layer and the metal member. By providing such an intermediate layer, the thermosetting resin layer can be prevented from peeling from the metal member.

JP 2013-131595 A

  In the technique of Patent Document 1, it is necessary to provide an intermediate layer between the silane coupling agent layer and the metal member, which increases the number of manufacturing steps necessary for manufacturing the composite. Therefore, in this specification, while being able to suppress exfoliation from a metal member of a thermosetting resin layer, the composite which can be manufactured more efficiently is provided.

The composite disclosed in this specification includes a thermosetting resin layer, a metal member, and a silane coupling agent layer that connects the thermosetting resin layer and the metal member. When the pH value of the extraction water of the thermosetting resin layer is N, the thickness of the thermosetting resin layer is t (mm), and the density of the thermosetting resin layer is d (g / cm ³ ), The silane coupling agent layer contains an amino group with a surface density of 5 × 10 ^{− (N + 6)} × t / d (mol / mm ² ) or more.

In addition, pH value of the extraction water of said thermosetting resin layer means the value measured by the following method. First, the after-cure sample having a thickness of 3 mm is pulverized. Next, after adding 50 ml of pure water to about 10 g of the sample and sealing it, the temperature is maintained at 125 ± 3 ° C. for 20 hours. During this time, H ⁺ is dissolved from the sample into pure water, and extracted water is obtained. Next, the sample is cooled to room temperature (18 ° C. to 28 ° C.), and the sample and the extracted water are separated. Thereafter, the pH value of the extracted water is measured.

  In addition, the surface density of the amino group of the silane coupling agent layer described above is the amino group contained in the silane coupling agent layer when viewed in a plane perpendicular to the interface between the silane coupling agent layer and the thermosetting resin layer. The amount per unit area of the group.

It is known that the thermosetting resin layer exhibits acidity when absorbing moisture. When the thermosetting resin layer absorbs moisture and the metal member is exposed to an acidic environment, the surface of the metal member is corroded and the thermosetting resin layer is peeled off from the metal member. In contrast, in the composite disclosed in the present specification, the silane coupling agent layer contains an amino group. The amino group is an alkaline functional group and has a property of neutralizing an acid (that is, proton (H ⁺ )). For this reason, even if the thermosetting resin layer absorbs moisture, the protons are neutralized by the amino groups in the silane coupling agent layer. When the silane coupling agent layer has an amino group at an area density of 5 × 10 ^{− (N + 6)} × t / d (mol / mm ² ) or more, protons cannot reach the metal member, and the metal member is corroded. Can be substantially prevented. Therefore, according to this composite, peeling of the thermosetting resin layer from the metal member can be effectively suppressed. Moreover, the structure of this composite body is obtained only by adjusting the material of the silane coupling agent layer. Since an additional step such as creating an intermediate layer is not required at the time of manufacturing the composite, the composite can be manufactured efficiently.

FIG. 3 is a cross-sectional view of the electronic component 10. The schematic diagram which shows the material structure inside the silane coupling agent layer 60. FIG. The schematic diagram which shows the material structure inside the silane coupling agent layer 60. FIG. The figure which shows the result of a demonstration experiment. The graph which shows the range of y> = 5 * 10- ^{(N + 6)} * t / d (however, t = 0.8, d = 1.9).

  FIG. 1 shows an electronic component 10 called a power card as a composite of the embodiment. The electronic component 10 includes a conductive portion 12 through which a current flows, a silane coupling agent layer 60, and a thermosetting resin layer 70. The conductive portion 12 includes a lead frame 14, a copper block 18, a semiconductor element 22, a lead frame 26 and a terminal 30.

  The lead frame 14 is made of nickel-plated copper. The copper block 18 is made of copper. The upper surface of the copper block 18 is joined to the lower surface of the lead frame 14 by a solder layer 16. The semiconductor element 22 is mainly composed of a semiconductor substrate. The main electrode on the upper surface of the semiconductor element 22 is joined to the lower surface of the copper block 18 by the solder layer 20. The lead frame 26 is made of nickel-plated copper. The upper surface of the lead frame 26 is joined to the electrode on the lower surface of the semiconductor element 22 by the solder layer 24. The terminal 30 is made of nickel-plated copper. The terminal 30 is disposed at a position away from the lead frame 26 in the lateral direction. The terminal 30 is connected to the signal electrode on the upper surface of the semiconductor element 22 by a bonding wire 28.

  Except for the upper surface of the lead frame 14, the lower surface of the lead frame 26, and the end of the terminal 30, the surface of the conductive portion 12 is covered with a silane coupling agent layer 60. The surface of the silane coupling agent layer 60 is covered with a thermosetting resin layer 70. In other words, the silane coupling agent layer 60 is disposed between the conductive portion 12 and the thermosetting resin layer 70. The thermosetting resin layer 70 is connected to the conductive portion 12 through the silane coupling agent layer 60. The silane coupling agent layer 60 connects the metal member (that is, the lead frame 14, the copper block 18, the lead frame 26, the terminal 30, the solder layers 16, 20, and 24) and the thermosetting resin layer 70 with high adhesive force. doing. The thermosetting resin layer 70 is an epoxy resin in this embodiment.

  When the electronic component 10 is manufactured, first, the conductive portion 12 is assembled by performing a soldering process, a wire bonding process, and the like. Next, a primer containing a silane coupling agent is applied to the surface of the conductive portion 12 except for the upper surface of the lead frame 14, the lower surface of the lead frame 26, and the end of the terminal 30. Thereby, the silane coupling agent layer 60 is formed. Thereafter, the thermosetting resin layer 70 is formed so as to cover the surface of the silane coupling agent layer 60 by a resin molding step. The electronic component 10 is completed through the above steps.

The silane coupling agent layer 60 contains an amino group. 2 and 3 schematically show the internal structure of the silane coupling agent layer 60. As shown in FIG. 2, the silane coupling agent layer 60 is bonded to the thermosetting resin layer 70 via amino groups (NH, NH ₂ ). The silane coupling agent layer 60 is bonded to the metal member through oxygen (O). When the thermosetting resin layer 70 absorbs moisture, protons (H ⁺ ) are generated. Protons diffuse from the thermosetting resin layer 70 to the silane coupling agent layer 60. Then, since the N atom has higher nucleophilicity than the O atom (it is easy to attract a proton), the proton is bonded to the amino group as shown in FIG. That is, a reaction of —NH ₂ + H ₃ O ⁺ → —NH ₃ ⁺ + H ₂ O occurs in the silane coupling agent layer 60. For this reason, the proton generated in the thermosetting resin layer 70 hardly reaches the metal member, and corrosion of the metal member is suppressed.

In order to prevent protons from reaching the metal member, the surface density y (mol / mm ² ) of amino groups in the silane coupling agent layer 60 is theoretically y ≧ 5 × 10 ^{− (N + 6)} × t / d. It is necessary to satisfy the relationship. Here, the surface density y is a unit area of amino groups contained in the silane coupling agent layer 60 when viewed in a plane perpendicular to the interface between the silane coupling agent layer 60 and the thermosetting resin layer 70. Means the amount. That is, the amount (mol) of amino groups contained in the silane coupling agent layer 60 within a specific range when viewed in a plane perpendicular to the interface is divided by the area (mm ² ) of the specific range. Mean value. It can be said that the amino group density (mol / mm ³ ) in the silane coupling agent layer 60 is integrated in the thickness direction of the silane coupling agent layer 60.

Further, the symbol N means a pH value of the extracted water of the thermosetting resin layer 70. In the present embodiment, the pH value of the water extracted from the thermosetting resin is measured by a measurement method defined in JIS Z 8802. More specifically, the after-cure sample (that is, thermosetting resin) having a thickness of 3 mm is pulverized. Next, about 10 g of a sample is taken in a container, and 50 ml of pure water is further added to the container and sealed. In that state, the sample is maintained at a temperature of 125 ± 3 ° C. for 20 hours. During this time, H ⁺ is dissolved from the sample into pure water, and extracted water is obtained. Next, the sample was cooled to room temperature (18 ° C. to 28 ° C.). The sample and the extracted water are separated by filtering with 5 filter paper. Thereafter, the pH value of the extracted water is measured.

  In addition, the symbol t means the thickness (mm) of the thermosetting resin layer 70. The thickness of the thermosetting resin layer 70 means the dimension of the thermosetting resin layer 70 measured in the direction perpendicular to the interface between the thermosetting resin layer 70 and the silane coupling agent layer 60.

Moreover, said code | symbol d means the density (g / cm < ³ >) of the thermosetting resin layer 70. FIG.

The inventors of the present application tested the samples 1 to 8 shown in FIG. 4 and investigated the peeling of the thermosetting resin. In all of Samples 1 to 8, a silane coupling agent layer is provided between the metal plate and the thermosetting resin layer. In samples 1 to 8, nickel-plated copper was used as the metal plate, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane was used as the silane coupling agent, and epoxy resin was used as the thermosetting resin. It was. Moreover, in samples 1-8, the pH value N of the extraction water of the thermosetting resin layer is 4.3, the thickness t of the thermosetting resin layer is 0.8 (mm), and the thermosetting resin layer The density d is 1.9 (g / cm ³ ). Under this condition, according to the relational expression (y ≧ 5 × 10− ^{(N + 6)} × t / d) described above, the surface density y necessary for preventing the peeling of the thermosetting resin layer is 1. 06 × 10 ⁻¹⁰ (mol / mm ² ). The surface density y of the amino group of the silane coupling agent layer is different between samples 1 to 8, and other conditions are the same. In sample 8, the surface density y is lower than 1.06 × 10 ⁻¹⁰ (mol / mm ² ), and in samples 1 to 7, the surface density y is higher than 1.06 × 10 ⁻¹⁰ (mol / mm ² ). A high temperature and high humidity test in which the samples 1 to 8 were exposed to an environment having a temperature of 85 ° C. and a humidity of 85% for 1000 hours was performed, and the presence or absence of peeling of the thermosetting resin layer was evaluated before and after that. As a result, as shown in FIG. 4, peeling of the thermosetting resin layer occurred only after sample 8 after the test, and peeling of the thermosetting resin layer did not occur in samples 1 to 7.

FIG. 5 shows a case where the thickness t of the thermosetting resin layer is 0.8 (mm) and the density d of the thermosetting resin layer is 1.9 (g / cm ³ ) as in the experiment of FIG. The range of the surface density y necessary for preventing the thermosetting resin layer from peeling (y ≧ 5 × 10 ^{− (N + 6)} × t / d (where t = 0.8, d = 1.9). )). A hatched range in FIG. 5 indicates a range in which peeling can be prevented. Moreover, the value of the samples 1-8 mentioned above is plotted in FIG. As is clear from FIG. 5, only the sample 8 where the peeling occurred is outside the proper range. Experimental results have demonstrated that peeling can be prevented by satisfying the relationship y ≧ 5 × 10 ^{− (N + 6)} × t / d.

As described above, when the surface density y of the amino group satisfies the relationship of y ≧ 5 × 10 ^{− (N + 6)} × t / d, the thermosetting resin layer can be prevented from peeling from the metal member. it can. According to this technique, it is possible to prevent the thermosetting resin layer from being peeled off from the metal member only by selecting an appropriate material as the thermosetting resin. For this reason, a composite_body | complex can be manufactured easily.

The embodiments have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings achieves a plurality of objects at the same time, and has technical usefulness by achieving one of them.

10: Electronic component 12: Conductive portion 14: Lead frame 16: Solder layer 18: Copper block 20: Solder layer 22: Semiconductor element 24: Solder layer 26: Lead frame 28: Bonding wire 30: Terminal 60: Silane coupling agent layer 70: Thermosetting resin layer

Claims (1)

A thermosetting resin layer;
A metal member;
A silane coupling agent layer connecting the thermosetting resin layer and the metal member;
A complex having
The pH value of the extraction water of the thermosetting resin layer is N,
The thickness of the thermosetting resin layer is t (mm),
The density of the thermosetting resin layer is d (g / cm ³ ),
And when
The silane coupling agent layer contains an amino group at a surface density of 5 × 10 ^{− (N + 6)} × t / d (mol / mm ² ) or more,
Complex.

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