JP5544937B2 - Electronic component sealing method and use thereof - Google Patents

Description

  The present invention relates to an electronic component sealing method and use thereof.

  A small control relay (hereinafter referred to as “relay”) is a device that controls an electric circuit by outputting an electric signal according to a condition such as an electric quantity or a physical quantity. Relays are widely used in home appliances such as televisions, microwave ovens, air conditioners, industrial machines such as machine tools and food-related machines, automobiles, railway-related transport equipment, etc., and are mounted on printed wiring boards in particular. Usage is increasing in electrical and electronic parts.

  One of the characteristics required for a relay is maintaining airtightness. In other words, the relay has a structure in which a metal terminal is bonded to a molding material. However, if the adhesion between the molding material and the metal terminal is insufficient, the relay may enter between contacts due to penetration of solder flux or invasion of malignant gas. The relay function of repeating on-off cannot be maintained. For this reason, there is a strong demand for a sealant that can provide strong adhesion between the molding material and the metal terminal and maintain the airtightness inside the relay.

  Conventionally, an epoxy resin composition is generally used as a sealant. In a one-component epoxy resin composition (epoxy resin composition of a type in which a latent curing agent is mixed with an epoxy resin composition in advance), dicyandiamide is generally used as the latent curing agent. . Also, latent curing agents excluding dicyandiamide (for example, epoxy resin adduct compounds) (Patent Document 1), mixtures of dicyandiamide and latent curing agents excluding dicyandiamide (Patent Document 2), latent imidazole compounds, dicyandiamide and the like A latent curing agent such as a mixture of latent curing agents (Patent Document 3) has been proposed. In addition, for example, in Non-Patent Document 1, when LCP (liquid crystal polymer) is used as a material for a relay molding material (a case for storing a switch, a coil, or the like), imidazole is added to the epoxy resin. It is described that the adhesion between LCP and epoxy resin is improved.

JP 2001-207029 A (released July 31, 2001) Japanese Patent No. 3797616 (registered on April 28, 2006) JP 2004-115552 A (published on April 15, 2004)

IEICE Technical Report, vol. 109, no. 173, EMD2009-56, pp. 157-162, August 21, 2009

  In recent years, in view of safety and environmental impact, etc., lead-free solder has been promoted. Thereby, the temperature of the solder when the relay is surface-mounted on the printed wiring board is 20-30 ° C. higher than the conventional 230-240 ° C. Therefore, heat resistance that can cope with this is also required for the sealant.

  Further, since the constituent members of the relay are mainly plastic materials except for the terminal materials, coils, magnets, etc., the curing temperature is desired to be 120 ° C. or lower.

  Therefore, the sealing agent can be cured at a low temperature of 120 ° C. or less, and even between high temperature processing conditions when performing the soldering process (for example, forming a molding material) The ability to maintain the airtightness of the relay by improving the adhesion of the cover and the base) is required.

  However, since dicyandiamide is a high melting point compound, when only dicyandiamide is used as a latent curing agent, an unreacted epoxy resin may remain at a curing temperature of 120 ° C. or lower. Furthermore, since the resulting cured product has insufficient heat resistance, there is a problem in that poor airtightness occurs.

  In addition, the latent curing agents described in Patent Documents 1 to 3 have a problem in that an airtight defect occurs due to insufficient heat resistance accompanying an increase in soldering temperature associated with lead-free operation.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an electronic component sealing method excellent in adhesiveness between constituent members made of a plastic material and use thereof.

  As a result of intensive studies on a method for sealing an electronic component excellent in adhesiveness between constituent members made of a plastic material, the present inventor has previously obtained a basic catalyst on at least the opposing surfaces of two members made of a resin material. It discovered that the sealing part which shows a desired effect could be formed by apply | coating and then apply | coating an epoxy resin composition and hardening | curing after that, and came to complete this invention.

  That is, in order to solve the above-described problem, the electronic component sealing method of the present invention uses two basic members and an epoxy resin composition to bond two components made of a resin material. An electronic component sealing method comprising: an application step of applying a basic catalyst to opposing surfaces of the two members facing each other; and an epoxy resin composition applied to the basic catalyst applied to the opposing surfaces And a curing step of curing the epoxy resin composition.

  According to the above configuration, in the curing step, the epoxy resin composition is brought into contact with the basic catalyst applied to the facing surface to cure the epoxy resin composition. The curing reaction starts by contacting with the basic catalyst applied to the surface. For this reason, the sealing part which consists of hardened | cured material becomes strong adhesiveness in the interface with two members, and airtightness improves.

  Therefore, according to said structure, the adhesiveness of the structural members which consist of a plastic material (resin material) can be improved greatly, and an airtight sealing can be performed.

  In the method for sealing an electronic component of the present invention, it is preferable that the epoxy resin composition is poured into the gap between the two members in the curing step.

  In the electronic component sealing method of the present invention, it is preferable that the basic catalyst is sprayed on the facing surface in the coating step.

  Thereby, a basic catalyst can be equally apply | coated to the opposing surface in two members.

  In the electronic component sealing method of the present invention, the two members are preferably composed of PBT (polybutylene terephthalate), and an imidazole compound or a tertiary amine compound is preferably used as the basic catalyst. In the electronic component sealing method of the present invention, it is preferable that the two members are composed of LCP (liquid crystal polymer), and an imidazole compound is used as the basic catalyst.

  As described above, by sealing with a combination of the material of the two members and the basic catalyst, the adhesion between the two members can be further improved.

  Moreover, it is preferable that the sealing method of the electronic component of this invention uses the epoxy resin composition containing a dicyandiamide in the said hardening process.

  According to said structure, a dicyandiamide shows the toughness provision effect and improves the adhesiveness of the member which consists of resin materials, and the metal member which consists of metal materials. Therefore, according to said structure, not only the adhesiveness of the two members which consist of resin materials but the adhesiveness of this member and a metal member can be improved.

  In the electronic component sealing method of the present invention, it is preferable that the relay is sealed by bonding a case and a base constituting the relay molding material.

  In order to solve the above problems, the two-component sealing kit of the present invention seals an electronic component by bonding two members made of a resin material using a basic catalyst and an epoxy resin composition. A two-component sealing kit for performing a basic catalyst for applying to the opposing surfaces of the two members facing each other, and an epoxy resin for contacting the basic catalyst applied to the opposing surfaces It is characterized by being composed of two components with the composition.

  If the two-component sealing kit of the present invention is used, it is possible to improve the adhesion between constituent members made of a plastic material (resin material).

  In order to solve the above-described problems, an electronic component of the present invention is an electronic component including two members made of a resin material and a sealing portion that seals between the two members. The part is composed of a cured product of an epoxy resin composition containing a basic catalyst, and the basic catalyst is located in the vicinity of both or one of the two members rather than the center position between the two members. It is characterized by a greater distribution of positions. The electronic component is preferably a relay.

  According to said structure, the said sealing part is comprised with the hardened | cured material of the epoxy resin composition containing a basic catalyst, and the said basic catalyst is the said 2 rather than the center position between the said two members. Since the positions near both of the two members or one of the members are more distributed, the sealing portion has higher adhesion at the interface with the two members, and the airtightness is improved. Therefore, according to said structure, the sealing part excellent in the adhesiveness of the structural members which consist of a plastic material (resin material) is realizable, and an electronic component with a favorable characteristic can be provided.

  As described above, the electronic component sealing method of the present invention includes an application step of applying a basic catalyst to opposing surfaces of the two members facing each other, and an epoxy applied to the basic catalyst applied to the opposing surfaces. And a curing step of bringing the resin composition into contact with and curing the epoxy resin composition.

  Therefore, there is an effect that the adhesiveness between the constituent members made of a plastic material (resin material) can be drastically improved and hermetic sealing can be performed.

It is a schematic diagram which shows the external appearance of a relay. (A) is the schematic diagram which showed typically the procedure of the sealing method in one Embodiment of this invention, (b) is the schematic diagram which showed the procedure of the conventional sealing method typically. . It is a figure which shows the other structure of the fitting structure of a case and a base which comprises the molding material of a relay. The sealing part of the relay which is an example of the electronic component of this embodiment is shown, (a) is sectional drawing which showed the structure of the sealing part schematically, (b) is the basic in a sealing part. It is the graph which showed distribution of a catalyst typically. It is a graph which shows an example of the temperature change of the solder in a reflow process.

  Hereinafter, embodiments of the present invention will be described in detail. Note that the present invention is not limited to this.

[1] Sealing method of electronic component (1-1) Sealing method of electronic component The sealing method of the present embodiment includes at least two members made of a resin material using a basic catalyst and an epoxy resin composition. In this method, the electronic component is sealed by bonding. The electronic component to which the sealing method of the present embodiment can be applied is not particularly limited as long as it is useful for performing hermetic sealing or insulating sealing, and is usually referred to as “electrical component”. There may be. For example, a relay, a switch, a sensor, etc. can be mentioned.

  Further, the two members to be bonded are not particularly limited as long as they are members made of a resin material. For example, the case where the case and base which comprise the molding material of a relay are adhere | attached can be mentioned. Hereinafter, as a sealing method according to the present embodiment, a sealing method for sealing a relay by bonding a case and a base will be described.

  FIG. 1 is a schematic diagram showing the appearance of a relay. As shown in FIG. 1, the relay 100 includes a molding material 1 and a metal terminal 2 in appearance. Various components constituting a relay such as a coil and a switch are stored in the molding material 1 (not shown). The molding material 1 includes a case 1a and a base 1b. The case 1a serves as a frame surrounding the base 1b. The base 1b is a product constituting the relay, that is, a relay body. The outer frames of the case 1a and the base 1b are made of a resin material and are configured to fit each other.

  In sealing the relay 100, the portion between the case 1a and the base 1b is a portion that is difficult to seal in order to seal with strong adhesion. In particular, it is important to maintain airtightness at the interface between the formed sealing portion and the case 1a and the base 1b. In the sealing method of the present embodiment, a basic catalyst is applied in advance to the site between the case 1a and the base 1b, and then an epoxy resin composition is applied. FIG. 2A is a schematic diagram schematically showing the procedure of the sealing method of the present embodiment, and FIG. 2B is a schematic diagram schematically showing the procedure of the conventional sealing method. is there.

  As shown in FIG. 2A, the sealing method of the present embodiment includes a coating process and a curing process performed after the coating process.

  In the application step, the basic catalyst A is applied to the opposing surfaces of the case 1a and the base 1b facing each other.

  In the curing step, the epoxy resin composition B is brought into contact with the basic catalyst A applied to the opposite surface, and the epoxy resin composition B is cured. Specifically, first, the epoxy resin composition B is applied to the upper surfaces of the case 1a and the base 1b. And this epoxy resin composition B is heated and hardened. While the epoxy resin composition B is being heated, the epoxy resin composition B flows into the gap between the case 1a and the base 1b, and comes into contact with the opposite surface to which the basic catalyst A is applied, thereby rapidly curing reaction. Starts. For this reason, the formed sealing part 3 becomes stronger in adhesion at the interface between the case 1a and the base 1b (the part surrounded by the dotted line in FIG. 2A), and the airtightness is improved.

  On the other hand, in the conventional sealing method, as shown in FIG. 2 (b), the epoxy resin composition B is formed on the upper surfaces of the case 1a and the base 1b without applying the basic catalyst A in advance. The composition is applied. For this reason, even if the epoxy resin composition B flows into the gap between the case 1a and the base 1b, the rapid curing reaction does not start on the facing surface. For this reason, the formed sealing portion 3 has poor adhesion at the interface between the case 1a and the base 1b, and cannot maintain airtightness.

  Moreover, in the conventional sealing method, since the one-component composition is used as the epoxy resin composition, a thermal latent curing agent having high reactivity with the epoxy resin is included in the epoxy resin composition in advance. become. Therefore, in the conventional sealing method, in order to stabilize the epoxy resin composition at room temperature, the thermal latent curing agent is in a solid state at room temperature (for example, 25 ° C.) and has a high temperature (100 to 120 ° C.). The compound that dissolves in is selected. Therefore, in the conventional sealing method, it is necessary to cure the epoxy resin composition at the melting temperature of the thermal latent curing agent, which is a restriction on lowering the curing temperature.

  On the other hand, in the sealing method of the present embodiment, when the epoxy resin composition B comes into contact with the basic catalyst A having a high reactivity with the epoxy resin in advance, a fast curing reaction is started. Therefore, since the epoxy resin composition B used in the sealing method of the present embodiment is prepared separately from the highly reactive basic catalyst A, the epoxy resin composition B is prepared at a relatively low temperature (for example, 60 ° C. to 80 ° C.). Can be cured. Therefore, according to the sealing method of the present embodiment, the epoxy resin composition B can be cured at a lower temperature than the conventional sealing method.

  As described above, in the sealing method of the present embodiment, further low-temperature curing is possible, and the portion between the case 1a and the base 1b is provided with strong adhesiveness to achieve high airtight sealing. .

  The case 1a and the base 1b to be bonded are not particularly limited as long as they are configured to be fitted to each other. For example, the structure shown by FIG. 3 can be mentioned. In the fitting structure shown in FIG. 3, the case 1a is configured to be fitted to the base 1b on both the upper surface and the inner peripheral surface. For this reason, the base 1b has a protruding portion protruding in the horizontal direction.

  In the case of the fitting structure shown in FIG. 3, in the application step, the basic catalyst A is applied to the opposing surfaces of the protruding portions of the case 1 a and the base 1 b. Then, in the curing step, the liquid epoxy resin composition B is poured into the gap between the case 1a and the base 1b, and the sealing portion is formed by heat curing.

(1-2) Coating step (1-2-1) Basic catalyst A basic catalyst is basic at room temperature and is activated by dissolution, decomposition, transfer reaction, etc. by heating. It is a compound that can be added to accelerate curing. Examples of the basic catalyst include aliphatic amines, modified amines, aromatic amines, imidazole compounds, secondary amine compounds, and tertiary amine compounds. These can be used singly or in combination of two or more.

  As the aliphatic amine, for example, ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, mensendiamine and the like can be used. Moreover, as a modified amine, an epoxy resin amine adduct compound, an epoxy resin imidazole adduct compound, a modified aliphatic polyamine compound, or the like can be used. Further, as the aromatic amine, metaphenylenediamine, diaminodiphenylmethane, or the like can be used.

  Among these, since the imidazole compound and the tertiary amine compound are chain polymerization catalysts, the reactivity with the epoxy resin is high. Therefore, in the method of the present invention, it is preferable to use an imidazole compound and a tertiary amine compound as the basic catalyst.

  As the imidazole compound, 2-methylimidazole, 2-undecylimidazole, 2-heptaimidazole, 1,2-dimethylimidazole, 2-ethyl-4-ethylimidazole, 1-benzyl-2-methylimidazole, 2-phenylimidazole 1-cyano-2-ethylimidazole, 1- (2-cyanoethyl) -2-ethyl-4-methylimidazole, and the like can be used.

  As the tertiary amine compound, dimethylalkylamine, methyldimethylamine, triethylamine, benzyldimethylamine, pyridine, picoline, 1,8-diazabiscyclooundecene, trisdimethylaminomethylphenol and the like can be used. .

(1-2-2) Basic Catalyst Application Method The basic catalyst application method is not particularly limited as long as the basic catalyst can be applied between the two members. For example, a hand coating method using brush or grease, a spray method in which a basic catalyst is sprayed in a mist form using a dispenser, a stamp method and the like can be mentioned. In particular, a spray method using a dispenser is preferable because the basic catalyst can be evenly applied to the opposing surfaces of the two members.

  Moreover, when apply | coating a basic catalyst using a dispenser, it is preferable that a basic catalyst is a liquid state. Even if the basic catalyst is solid at normal temperature, it can be applied by spraying the basic catalyst using a dispenser if it is liquefied by heating. It is also possible to selectively spray the basic catalyst through a patterned mask.

(1-2-3) Application amount of basic catalyst In the sealing method of this embodiment, when the application amount of the basic catalyst is small, the adhesiveness of the case and the base is lowered, so that the airtightness becomes insufficient. . On the other hand, when the application amount of the basic catalyst is large, the epoxy resin composition and the basic catalyst are mixed, the viscosity of the mixed liquid decreases, and the flow of the epoxy resin composition to the side surface of the molding material increases. For this reason, there is a concern that the epoxy resin composition may enter the molding material and adversely affect the relay characteristics. From such a viewpoint, the basic catalyst is preferably applied in an amount of 0.1 to 5 mg, more preferably 0.1 to 1 mg, and particularly preferably 0.15 to 0.5 mg with respect to 90 mg of the epoxy resin composition.

(1-3) Curing Step (1-3-1) Epoxy Resin Composition The epoxy resin composition in the present invention is an epoxy resin as a main agent, dicyandiamide as a curing agent, a thermal latent curing agent, and an inorganic as a filler. Contains filler.

  The epoxy resin means an epoxy resin that has an aromatic ring such as a benzene ring, a naphthalene ring, or a hydrogenated benzene ring or a hydrogenated aromatic ring and two or more terminal epoxy groups, and is liquid around room temperature. . A substituent such as alkyl and halogen may be bonded to the aromatic ring and the hydrogenated aromatic ring.

  The terminal epoxy group and the aromatic ring or hydrogenated aromatic ring are bonded by oxyalkylene, poly (oxyalkylene), carbooxyalkylene, carbopoly (oxyalkylene), aminoalkylene, or the like. In addition, the aromatic ring and the hydrogenated aromatic ring are bonded directly or with alkylene, oxyalkylene, poly (oxyalkylene) or the like.

  Specific examples of the epoxy resin include bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol A ethylene oxide 2 mol adduct diglycidyl ether, bisphenol A-1,2-propylene oxide 2 mol adduct diglycidyl ether, Hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, orthophthalic acid diglycidyl ester, tetrahydroisophthalic acid diglycidyl ester, N, N-diglycidyl aniline, N, N-diglycidyl toluidine, N, N-di Glycidylaniline-3-glycidyl ether, tetraglycidyl metaxylenediamine, 1,3-bis (N, N-diglycylaminomethylene) cyclohexane, tetrabromobisphenol Diglycidyl ether and the like.

  In the present invention, one or more kinds selected from these epoxy resin groups are used. The ratio in the case of using together is arbitrary. In view of the heat resistance of the cured product, it is preferable to use a combination of bisphenol A diglycidyl ether and hydrogenated bisphenol A diglycidyl ether, a combination of bisphenol F diglycidyl ether and hydrogenated bisphenol F diglycidyl ether, or the like. In addition, these illustrated epoxy resins may be used alone or in combination of two or more.

  Dicyandiamide is a single compound. Dicyandiamide is a compound that exhibits a toughness-imparting effect and is widely used as a latent curing agent, but has a high melting point (melting point: about 180 to 200 ° C.), and is required when producing electronic components such as small electronic components for control. At a low curing temperature of less than or equal to ° C., unreacted materials may remain. In the epoxy resin composition, in order to obtain a curing temperature of 120 ° C. or less, a thermal latent curing agent described later is used in combination. Cyandiamide also has a function of improving the adhesion between the epoxy resin and the metal that is the terminal material.

  A thermal latent curing agent is a curing agent that is stable in a mixed system with an epoxy resin, does not have an activity of curing the epoxy resin at room temperature, and is activated by dissolution, decomposition, transition reaction, etc. by heating. It is a compound that functions as a curing accelerator for the resin.

  The epoxy resin composition is preferably prepared so as to be cured by heating at 80 ° C. to 120 ° C.

  Examples of the thermal latent curing agent include an epoxy resin adduct compound, a modified aliphatic amine compound, an imidazole compound, a urea derivative, and a tertiary amine compound. These may be used alone or in combination of two or more.

  The epoxy resin composition may contain an inorganic filler. Specific examples of the inorganic filler include, for example, calcium carbonate, fused silica, crystalline silica, alumina, titanium oxide, silica titania, boron nitride, aluminum nitride, silicon nitride, magnesia, magnesium silicate, talc, mica and the like. These may be used alone or in combination of two or more. Of these, silica, alumina and talc are preferably used alone or in combination of two or more.

  In the epoxy resin composition, a thixotropic agent for adjusting viscosity, a colorant such as carbon black and iron oxide, and the like may be mixed as necessary. For example, in the examples described later, carbon black is used as the colorant.

(1-3-2) Heating temperature The epoxy resin composition can be cured by heating the epoxy resin composition. Although it does not specifically limit as heating temperature, Since the temperature at the time of hardening gives a fluctuation | variation to a relay characteristic, it is preferable that it is 60 to 120 degreeC, and it is more preferable that it is 80 to 110 degreeC.

  When the electronic component is a relay, since the constituent members of the relay are mainly plastic materials other than terminal materials, coils, magnets, etc., it is desirable to cure the epoxy resin composition at a low temperature of 120 ° C. or lower. In the sealing method of the present embodiment, as described above, the epoxy resin composition B is prepared separately from the highly reactive basic catalyst A, and has a relatively low dissolution temperature (for example, 60 ° C. to 80 ° C.). Even if a thermal latent curing agent is selected, it can be stabilized at room temperature, and can be sufficiently cured at a low temperature of 120 ° C. or lower.

(1-4) Material of relay molding material (case and base) The case and base constituting the relay molding material are used to house switches, coils, etc., and the material is particularly limited. However, PBT (polybutylene terephthalate) and LCP (liquid crystal polymer) are widely used. PBT is one of engineering plastics and has excellent thermal stability, dimensional accuracy, and electrical characteristics, and thus is widely used for electrical parts, electronic parts, automobile parts, and the like. However, the adhesiveness is high but the heat resistance is low. On the other hand, LCP is easy to obtain heat resistance, excellent strength characteristics, low thermal expansibility and orientation due to rigid linear alignment, but has the disadvantage of low adhesion.

  So far, no adhesive having good adhesion to both PBT and LCP has been found, but the sealing method of the present embodiment can be cured at a low temperature of 120 ° C. or less, so It can be sufficiently applied to PBT with low adhesiveness and has a high sealing ability, so it can be applied to LCP with low adhesiveness. Therefore, both PBT and LCP can be preferably used as adhesion targets of the sealing method of the present embodiment.

  In particular, when the molding material is composed of PBT, it is preferable to use an imidazole compound or a tertiary amine compound as the basic catalyst. Moreover, when a molding material is comprised by LCP, it is preferable to use an imidazole compound as a basic catalyst. By using the basic catalyst in this way, it becomes possible to improve the airtightness of the sealing portion as shown in the examples described later.

  Moreover, when the material of a molding material is LCP, it has been reported that the adhesiveness of LCP and an epoxy resin can be improved by using the mixture which added the imidazole to the epoxy resin (nonpatent literature 1). In the sealing method of the present embodiment, by directly applying imidazole to the surface of the molding material, the effect of improving the adhesiveness appears remarkably.

  Also, when mounting electronic components such as relays on the board, the metal terminals are fixed to the board using solder, but when performing reflow or flow processing using lead-free solder, conventional solder is used. The temperature of the solder increases by 20 to 30 ° C. compared to the case of using, and the temperature of the entire electronic component reaches a maximum of 250 to 260 ° C.

  When an epoxy resin composition containing dicyandiamide is used in the curing process, the metal terminal and the molding material can be kept sealed even after being subjected to such a high temperature treatment, and after the lead-free solder treatment. Even airtightness can be maintained. Therefore, by adhering at least two members using the sealing method of the present embodiment, the electronic component can be hermetically sealed or insulatively sealed without causing leakage between the members to be bonded. . Whether or not an electronic component is hermetically sealed is confirmed, for example, by conducting a seal (air tightness) test method (relay handbook, written by Kunio Kanno, Morikita Publishing) of the Japan Electric Control Equipment Industries Association Standard NECA0404 can do. Whether or not the electronic component is insulated and sealed can be confirmed by, for example, a tracking resistance method (JIS C2134).

[2] Two-component sealing kit The two-component sealing kit of the present embodiment is composed of two components, a basic catalyst and an epoxy resin composition. A basic catalyst is a component for apply | coating to the mutually opposing surface in two members, and an epoxy resin composition is a component for making it contact the said basic catalyst apply | coated to the opposing surface.

  The two-component sealing kit means a kit composed of two components and used alone in each step without mixing the two components in the step of the sealing method. In the present embodiment, the basic catalyst used in the coating process and the epoxy resin composition used in the curing process correspond to the two-component sealing kit. In actual use, a manual describing the procedure as described in [1] Sealing method of electronic parts is attached to the two-component sealing kit.

  Since this two-component sealing kit is used without mixing two components, it is a concept contrasted with a one-component epoxy resin composition in which an epoxy resin, a curing agent and a curing accelerator are mixed in advance. In addition, the two-component sealing kit is separated into two components, an epoxy resin and a curing agent / curing accelerator mixture, or an epoxy resin / curing accelerator mixture and a curing agent. It is a concept that is contrasted with a two-component epoxy resin composition used by mixing both.

  Two-component epoxy resin compositions have drawbacks such as poor curing due to measurement errors during compounding and short pot life after compounding. In addition, when polyamidoamine, aliphatic amine, or the like is used as the curing agent, the heat resistance of the cured product is low, and airtight defects after soldering often occur.

  In recent years, one-component epoxy resin compositions have been increasingly used because they have low material loss and high productivity. However, as described above, it is necessary for the one-part epoxy resin composition to cure the epoxy resin composition at the melting temperature of the thermal latent curing agent, which is a restriction on lowering the curing temperature.

  The two-component sealing kit of this embodiment is used without mixing the basic catalyst used in the coating process and the epoxy resin composition used in the curing process. By such use, it is possible to realize a highly airtight seal by providing strong adhesion between the case and the base.

[3] Electronic Component The electronic component of the present embodiment has a configuration including a sealing portion formed by the above-described sealing method. That is, the electronic component of this embodiment is an electronic component that includes two members made of a resin material and a sealing portion that seals between the two members, and the sealing portion 3 is a basic catalyst. It is comprised with the hardened | cured material of the epoxy resin composition containing this.

  4 shows a sealing portion of a relay which is an example of the electronic component of the present embodiment, and FIG. 4A is a cross-sectional view schematically showing the configuration of the sealing portion, and FIG. These are the graphs which showed typically distribution of the basic catalyst in the sealing part.

  As shown in FIGS. 4A and 4B, the sealing portion 3 that seals the case 1a and the base 1b includes a basic catalyst rich layer 3a containing a large amount of basic catalyst. The basic catalyst rich layer 3a is formed in contact with the case 1a and the base 1b. That is, the basic catalyst in the sealing portion 3 is closer to the position in the vicinity of both the case 1a and the base 1b than in the center position between the case 1a and the base 1b (center position between the two members). Is more distributed. The “near position” here is a position where the distance from the case 1a and the base 1b is in the range of 5 to 30 μm.

  Whether or not a large amount of the basic catalyst is distributed in the vicinity of the case 1a and the base 1b in the sealing portion 3 can be confirmed by, for example, microscopic imaging FT-IR or gas chromatography mass spectrometry GC-MS. In particular, microscopic imaging FT-IR is preferable because it can be easily and accurately analyzed.

  The inventor confirmed the distribution of the basic catalyst for the sealing portion 3 using microscopic imaging FT-IR. Hereinafter, the result of analyzing the sealing portion 3 by microscopic imaging FT-IR will be described. In this analysis, sealing part 3 is produced using an imidazole compound as a basic catalyst. Then, a micro attachment (600UMA) is attached to FT-IR (3100FT-IR) manufactured by Varian, and the base 3 in the vicinity of the case 1a, in the center between the case 1a and the base 1b, and in the vicinity of the base 1b. The amount of the neutral catalyst was measured.

  As a result, in the vicinity of case 1a coated with an imidazole compound as a basic catalyst and in the vicinity of base 1b, an increase in peaks near 950 cm to 1000 cm −1 (peaks derived from imidazole) was confirmed, and areas near case 1a and base 1b The amount of the basic catalyst was larger than that in the central part of the case 1a and the base 1b. Therefore, the improvement of the airtightness by adding the basic catalyst is considered to be because the basic catalyst exists in the vicinity of the adhesion site.

  The electronic component of the present embodiment is not limited to a relay, and any electronic component may be used as long as it has utility in performing hermetic sealing or insulating sealing, and may be generally referred to as an electrical component. . For example, a switch, a sensor, etc. can be mentioned.

Preparation of epoxy resin composition (B) 100 parts by weight of bisphenol A type epoxy resin AER260 (manufactured by Asahi Kasei) as an epoxy resin, and imidazole-based curing agent (trade name: PN-23, Ajinomoto Fine Techno Co., Ltd.) as a latent curing agent 5 parts by weight, 8 parts by weight of dicyandiamide (trade name: DDA5, manufactured by PTI Japan), 20 parts by weight of calcium carbonate (trade name: manufactured by Nitto Powder Co., Ltd.) as filler, and 1 part by weight of carbon black as a colorant After mixing, kneading was performed using a mixing roll to prepare an epoxy resin composition (B).

[Example 1]
First, 0.5 mg of an imidazole compound (trade name: 2E4MZ, manufactured by Shikoku Kasei), which is a basic catalyst, is used as a curing agent (A) using a spray nozzle (trade name: 781-SS, manufactured by Sanei Tech). As shown in Fig. 2, the coating was applied to the opposing surfaces of the case and the base. The base material (material) of the case and the base is LCP (liquid crystal polymer). Thereafter, 90 mg of the epoxy resin composition (B) was applied to the upper surfaces of the case and the base. And the epoxy resin composition (B) was hardened for 60 minutes at 100 degreeC, and the relay was produced.

  The produced relay was subjected to reflow treatment using a reflow furnace (Toyo Corporation, NRY-540S-7Z). FIG. 5 is a graph showing an example of solder temperature change in the reflow process. The horizontal axis represents time, and the vertical axis represents temperature. In this embodiment, the reflow process (IRS method) is performed by preheating for 90 to 120 seconds (t1 in FIG. 5) at 150 ° C. (T1 in FIG. 5) and within 200 seconds (T2 in FIG. 5) within 30 seconds (FIG. 5). 5 at t2) and the maximum temperature was 250 ° C. (T3 in FIG. 5) or less. Details of the IRS method are described in the Quality / Reliability Handbook (Sony Corporation, etc.).

  Then, it was immersed in a fluorine-based inert liquid heated to 70 ° C. for 1 minute in accordance with the test method for sealing (air tightness) of the control equipment (NECA4044 of the Japan Electric Control Equipment Industries Association) (Relay Handbook, Kunio Kanno, Morikita Publishing), and airtight A sex evaluation test was conducted. The results were visually observed and represented as ◎ when the adhesiveness was high and no bubbles were generated during the immersion, ◯ when no bubbles were generated, and × when the bubbles were generated during immersion. The presence / absence of the basic catalyst and the results of the base material and the airtightness evaluation test are shown in Table 1.

  Further, the formed molding material (case and base) of the relay was disassembled, and the flow of the epoxy resin between the case and the base was confirmed, and the presence or absence of the uncured epoxy resin component was visually confirmed. Specifically, the above-mentioned observation by visual observation first observed whether or not a transparent portion was separated in the epoxy resin composition in the region sandwiched between the case and the base. And when the transparent part was not isolate | separated, it judged as (circle) not having isolate | separated the uncured component. When a transparent part was confirmed, it was determined as x because separation of uncured components occurred.

[Examples 2 to 5, Comparative Examples 1 to 7]
In Example 2, as shown in Table 1, a tertiary amine compound (trade name: JER3010, manufactured by Japan Epoxy Resin Co., Ltd.), which is a basic catalyst different from Example 1, was used as a curing agent. The same airtightness evaluation test as above, confirmation of inflow, and determination of the presence or absence of an uncured epoxy resin component

  In Example 3, as shown in Table 1, the same tertiary amine compound as in Example 2 was used as the curing agent (A), and the base material on which the curing agent (A) was applied was used in Example 1. Using PBT (polybutylene terephthalate) different from the base material used, the same airtightness evaluation test as in Example 1, confirmation of inflow, and the presence or absence of an uncured epoxy resin component were performed.

  In Example 4, as shown in Table 1, the same imidazole compound as in Example 1 was used as the curing agent (A), and the same PBT as in Example 3 was used as the base material on which the curing agent (A) was applied. The ratio of the coating amount of the curing agent (A) to the coating amount of the curing agent (A) and the epoxy resin composition (B) (in Table 1, expressed as A / (A + B) * 100 (%)) is an example. The ratio was different from 1, and the same airtightness evaluation test as in Example 1, confirmation of inflow, and the presence or absence of an uncured epoxy resin component were performed.

  In Example 5, as shown in Table 1, the same curing agent (A) and substrate as in Example 1 were used. And the ratio of the coating amount of the curing agent (A) to the coating amount of the curing agent (A) and the epoxy resin composition (B) is different from that in Example 1, and the same airtightness evaluation test as in Example 1; Determination of the presence or absence of uncured epoxy resin and determination of inflow were performed.

  In Comparative Example 1, as shown in Table 2, glutaric acid (manufactured by Tokyo Chemical Industry Co., Ltd.) different from Example 1 was used as the curing agent (A), and Example 1 was used as the base material on which the curing agent (A) was applied. Using the same LCP as in Example 1, the same airtightness evaluation test as in Example 1, confirmation of inflow, and the presence or absence of an uncured epoxy resin component were performed.

  In Comparative Examples 2 and 3, as shown in Table 2, the step of applying the curing agent (A) was omitted, and only the step of applying the epoxy resin composition (B) was performed. A property evaluation test, confirmation of inflow, and the presence or absence of an uncured epoxy resin component were performed. In Comparative Example 2, the same PBT as in Example 3 was used as the base material. In Comparative Example 3, the same LCP as in Example 1 was used as the base material.

  In Comparative Examples 4 and 5, as shown in Table 2, the same curing agent (A) and substrate as in Example 1 were used. And the ratio of the coating amount of the curing agent (A) to the coating amount of the curing agent (A) and the epoxy resin composition (B) is different from that in Example 1, and the same airtightness evaluation test as in Example 1; The flow was confirmed and the presence or absence of an uncured epoxy resin component was determined.

  In Comparative Example 6, as shown in Table 2, a mixture of the curing agent (A) and the epoxy resin composition (B) was prepared. And after apply | coating this mixture to the epoxy resin composition application surface in the molding material which comprises a relay, it carries out similarly to Example 1, an airtightness evaluation test, confirmation of inflow, and determination of the presence or absence of an uncured epoxy resin component Went.

  In Comparative Example 7, as shown in Table 2, the order of the step of applying the curing agent (A) and the step of applying the epoxy resin composition (B) was reversed to that of Example 1, In the same manner as in No. 1, an airtightness evaluation test, confirmation of inflow, and the presence or absence of an uncured epoxy resin component were performed.

  From the comparison results of Examples 1 to 5 and Comparative Examples 1 to 3 in Tables 1 and 2, the epoxy resin was applied in a state where a basic catalyst was previously applied as a curing agent (A) to the facing surfaces of the case and the base. It was found that the airtightness was improved by applying and curing the composition (B) (described as “A → B → curing” in Tables 1 and 2). Moreover, from the confirmation of inflow and the determination result of the presence or absence of the uncured epoxy resin component, in Comparative Examples 1 to 3, the uncured epoxy resin component was confirmed, while in Examples 1 to 5, the uncured epoxy resin component was It was not confirmed. In a seal relay using an epoxy resin as a sealant, it is known that this uncured epoxy resin component adheres to the contact point, thereby shortening the life of the relay characteristics (for example, Patent Publication No. 2001-220429). (Released on August 14, 2001). Therefore, it has been found that the sealing method of the present invention not only improves the airtightness but also has a remarkable effect in suppressing the uncured epoxy resin component that affects the life of the relay.

  Moreover, from the results of Example 1 and Example 2, it was found that when the base material was LCP, airtightness could be improved by applying an imidazole compound as the curing agent (A). Moreover, from the results of Example 3 and Example 4, when the base material is PBT, the airtightness can be improved by applying any of the imidazole compound and the tertiary amine compound as the curing agent (A). I knew it was possible.

  The results of Comparative Examples 6 and 7 in Tables 1 and 2 indicate that the basic catalyst (curing agent (A)) and the epoxy resin composition (B) are applied and cured or applied. If the order is changed, it means that airtightness cannot be shown, and further, an uncured epoxy resin component is also confirmed. Therefore, the order of application of the basic catalyst (curing agent (A)) and the epoxy resin composition (B) (“A → B → curing”) improves the airtightness and suppresses the uncured epoxy resin component. I found it important.

  Moreover, even if it apply | coats and hardens | cures an epoxy resin composition (B) in the state which apply | coated the basic catalyst as a hardening | curing agent (A) from the result of the comparative example 4 in Table 2, an epoxy resin composition (B). It was found that when the coating amount of the curing agent (A) was too large, the viscosity of the mixed liquid of the curing agent (A) and the epoxy resin composition (B) decreased, and the flow into the molding material increased. On the other hand, from the result of Comparative Example 5, it was found that when the amount of the curing agent (A) applied to the epoxy resin composition (B) is too small, the adhesiveness is lowered and airtightness is not exhibited. From the results of Comparative Examples 4 and 5 and the results of Examples 1 to 5, the optimum amount of the basic catalyst that exerts the effects of the present invention is 0.1 to 5 mg with respect to 90 mg of the epoxy resin composition. I found out.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  The sealing method of the present invention comprises: an application step of applying a basic catalyst to opposing surfaces of two members facing each other; an epoxy resin composition in contact with the basic catalyst applied to the opposing surfaces; and the epoxy resin And a curing step for curing the composition, it is possible to produce an electronic component that can be cured at low temperature and has excellent adhesion. Therefore, it can be widely used in various electronic industries.

1 Molding material 1a Case (member)
1b Base (member)
2 Metal terminal 3 Sealing part 100 Relay (electronic component)

Claims (9)

An electronic component sealing method for sealing an electronic component by adhering two members made of a resin material using a basic catalyst and an epoxy resin composition,
An application step of applying a basic catalyst to both surfaces of the two members facing each other in the two members;
And a curing step of bringing the epoxy resin composition into contact with the basic catalyst applied to the opposite surface and curing the epoxy resin composition.   The method for sealing an electronic component according to claim 1, wherein in the curing step, the epoxy resin composition is poured into a gap between the two members.   2. The electronic component sealing method according to claim 1, wherein the basic catalyst is sprayed on the facing surface in the coating step. The two members are composed of PBT (polybutylene terephthalate),
The method for sealing an electronic component according to claim 1, wherein an imidazole compound or a tertiary amine compound is used as the basic catalyst. The two members are composed of LCP (liquid crystal polymer),
The method for sealing an electronic component according to claim 1, wherein an imidazole compound is used as the basic catalyst.   The method for sealing an electronic component according to claim 1, wherein an epoxy resin composition containing dicyandiamide is used in the curing step.   The method for sealing an electronic component according to claim 1, wherein the relay is sealed by adhering a case and a base constituting a molding material of the relay. An electronic component comprising two members made of a resin material and a sealing portion that seals between the two members,
The sealing part is composed of a cured product of an epoxy resin composition containing a basic catalyst,
The electronic component according to claim 1, wherein the basic catalyst is distributed more in the vicinity of both the two members than in the central position between the two members. The electronic component according to claim 8 , wherein the electronic component is a relay.

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