JPWO2014132973A1 - Electronic component device manufacturing method and electronic component device - Google Patents

Abstract

It is possible to reduce the weight of electronic component devices, reduce manufacturing costs, shorten manufacturing time, and reliably prevent the adverse effects of moisture, moisture, dust, etc., and even when manufacturing by injection molding Provided are an electronic component device manufacturing method and an electronic component device in which the reliability of components does not deteriorate. The molten sealing body 6 is supplied so as to enclose the electronic component 2, and an integration process is performed so that the electronic component 2 is integrated with the sealing body 6. The sealing body 6 is thermoplastic. A foaming agent composition is added to the resin and foamed in the integration step. The thermoplastic resin has a melt viscosity of 10 dPa · s or more at 200 ° C. and a shear rate of 1000 (1 / s). Less than 850 dPa · s and Shore D hardness is less than 60 degrees.

Description

  The present invention relates to a method of manufacturing an electronic component device that is provided in an electronic electrical device such as an automobile or a home appliance and has an electronic component therein, and the electronic component device.

  Various electronic components housed inside the electronic component device are adversely affected by moisture, moisture, dust, and the like. Therefore, a sealed structure is required for an electronic component device that stores an electronic component that is used in an environment that is susceptible to such moisture, moisture, and dust.

  As a conventional electronic component device and method for manufacturing an electronic component device that protects electronic components from the influence of moisture, etc., the electronic components are housed in a housing made of a casing, and the housing is filled with a liquid resin and solidified. Patent Documents 1 and 2 disclose an electronic component that is sealed in a sealed state.

  According to this type of electronic component device, since the periphery of the electronic component is sealed with resin, the electronic component can be prevented from being exposed to the external atmosphere, and the electronic component is adversely affected by moisture, moisture, dust, and the like. Can be reduced.

Japanese Patent Laid-Open No. 9-121090, FIG. JP-A-7-99279

  However, in the above-described conventional electronic component device, what is filled between the electronic component device and the housing is simply resin, so that the electronic component device becomes heavy when the resin filling volume is large, There has been a problem that the manufacturing cost is increased due to a large filling amount.

  In addition, when a thermosetting resin (epoxy resin) is used as the resin for covering the electronic component, a relatively long time is required in the curing process, and thus there is a disadvantage that the working efficiency is deteriorated. In addition, when an electronic component device is manufactured by heating to a high temperature using a thermosetting resin or the like, distortion occurs at the interface between the resin and the electronic component due to the difference in linear expansion coefficient between the electronic component and the resin. There is a possibility that the resin and the electronic component may be separated from each other at the boundary without being able to absorb this strain. When the resin and the electronic component are separated from each other at the boundary surface, an external atmosphere may be communicated with the boundary surface. In this case, adverse effects such as moisture, moisture, and dust cannot be prevented. Further, if the electronic component is covered with a hard resin, the difference in linear expansion due to temperature change during use cannot be absorbed and distortion occurs, causing damage to the electronic component or cracking in the soldered portion.

  It is also conceivable to manufacture an electronic component device by injection molding using a mold, but in this case, when the molten resin is filled in the mold, the viscosity and mass of the molten resin are relatively large. In some cases, electronic parts are subjected to a large pressure from the molten resin. As a result, the reliability of the electronic component may be reduced, such as the position of the electronic component being shifted or the electronic component being deformed or damaged. Furthermore, when the electronic component device is used in a vibrating environment such as an automobile, external vibration may be directly transmitted to the electronic component through the resin, and this also reduces the reliability of the electronic component.

  Furthermore, when the thermoplastic resin is foamed and used by the above method, the sealing performance is lowered due to the voids inside the thermoplastic resin due to bubbles, or the substrate on which the electronic component is mounted has no complicated cavity. The foamed resin melted following the shape flowed in, and it was difficult to improve the adhesion between the mounted component or substrate and the sealing layer.

  The present invention solves the above-described problems, and can reduce the weight of electronic component devices, reduce manufacturing costs, shorten manufacturing time, and can reliably prevent adverse effects such as moisture, moisture, and dust. An object of the present invention is to provide an electronic component device manufacturing method and an electronic component device that improve adhesion and sealing properties and that do not reduce the reliability of electronic components even when manufactured by injection molding. Is.

  The method of manufacturing an electronic component device according to the present invention solves the above-described problem, and supplies a molten sealing body so as to enclose the electronic component so that the electronic component is integrated with the sealing body. The sealing body is formed by adding a foaming agent composition to a thermoplastic resin and foamed in the integration step, and the shear rate of the thermoplastic resin at 200 ° C. Is 1000 (1 / s), the melt viscosity is 10 dPa · s or more and less than 850 dPa · s, and the Shore D hardness is less than 60 degrees.

Moreover, the manufacturing method of the electronic component device of the present invention is characterized in that an elongational viscosity of the thermoplastic resin is larger than the melt viscosity.
Moreover, the manufacturing method of the electronic component device of the present invention is characterized in that the thermoplastic resin has an extensional viscosity of 3 times or more of a melt viscosity.

  The electronic component device of the present invention includes an electronic component and a sealing body that covers the electronic component, and the sealing body is formed of a foamed thermoplastic resin. The melt viscosity at a shear rate of 1000 (1 / s) at 10 ° C. is 10 dPa · s or more and less than 850 dPa · s, and the Shore D hardness is less than 60 degrees.

  In the electronic component device manufacturing method of the present invention, in the integration step, the electronic component is disposed in a cavity of a mold for injection molding, and the sealing body is injected into the cavity in a molten state. It is characterized by.

  Further, in the method of manufacturing the electronic component device, the electronic component or the circuit board on which the electronic component is mounted is fixed by a fixing component attached to a storage body that stores the electronic component, or injection of the sealing body is started. Sometimes, it may protrude into the cavity of the mold to hold at least one of the electronic component and the circuit board, and may be held by a holding component that exits from the cavity at the end of injection.

  Moreover, you may use what consists of an inorganic particle, a foaming agent, and a binder component as a foaming agent composition mixed with a thermoplastic resin as a sealing body. In addition, when performing injection molding using a mold, the mold is composed of a fixed mold and a movable mold, electronic parts are disposed in a cavity, and the sealed mold is closed. A stationary body may be injected into the cavity, and then the movable mold may be retracted when the sealing body is foamed.

  In addition, as the electronic component device of the present invention, a storage body that houses the electronic component may be provided, and the sealing body may be disposed in a state where the electronic component is covered in the storage body. Moreover, an electronic component may be mounted on a circuit board, an electric wire may be connected to the electronic component or the circuit board at the connection portion, and the connection portion side of the electric wire may be covered with the sealing body. Moreover, the foaming agent composition which has an inorganic particle, a foaming agent, and a binder component may be contained in the said sealing body.

  According to the present invention, by using a foamed thermoplastic resin as the sealing body that covers the electronic component, the thermoplastic resin is used in comparison with the case where an unfoamed thermoplastic resin is used as the sealing body. The amount (mass) of resin used can be reduced, and the weight can be reduced and the manufacturing cost can be reduced. Moreover, since the thing which foamed the thermoplastic resin is used as the sealing body which covers an electronic component, the elasticity and contractility (cushion property) of a sealing body become large. As a result, even when the electronic component device is used in an environment such as an automobile that frequently vibrates, external vibration is easily absorbed by the thermoplastic resin, and external vibration is not easily transmitted directly to the electronic component. Therefore, damage due to stress cracks of the electronic component due to vibration is reduced, and reliability is improved.

  Further, the thermoplastic resin has a melt viscosity of 10 dPa · s or more and less than 850 dPa · s at a shear rate of 1000 (1 / s) at 200 ° C. and a Shore D hardness of less than 60 degrees. High elasticity and shrinkage (cushioning), so it absorbs the difference in linear expansion due to temperature changes during use and does not cause distortion that damages electronic components or cracks in soldered parts. It can be used in an environment with a higher temperature change. In addition, a thermoplastic resin is used as the resin for covering the electronic component, and even when the molten thermoplastic resin is cooled and solidified, a relatively short time is required, and there is an advantage that the work efficiency is good.

  Further, it is preferable to use a thermoplastic resin having an extensional viscosity larger than the melt viscosity. Furthermore, the melt viscosity when the shear rate is 1000 (1 / s) at 200 ° C. is 10 dPa · s or more and 850 dPa · s. It is more preferable to use a thermoplastic resin having an elongation viscosity of 3 or more times the melt viscosity as the thermoplastic resin.

  By using this thermoplastic resin, when the foaming is performed, the decomposition gas generated by the decomposition of the foaming agent swells and swells while maintaining the shape of the bubbles in a state where the molten thermoplastic resin is sufficiently mixed. The bubbles are not broken, and one bubble is not connected to other bubbles surrounding the periphery, so that an independent shape can be maintained. That is, at the time of foaming, air bubbles can be generated satisfactorily, and the reliability as a sealed body covering the electronic component is improved.

  Further, in the integration step, an electronic component is disposed in a cavity of a mold for injection molding, and the sealing body is injected into the cavity in a molten state, whereby a thermoplastic resin into the mold cavity is obtained. Since the viscosity and mass of the thermoplastic resin at the time of filling can be reduced, it is possible to prevent the pressure from the sealing body acting on the electronic component from being reduced and the electronic component from being displaced, deformed or damaged, The reliability of electronic parts is improved. Further, as described above, since the sealing body has a large elasticity and shrinkability (cushioning property), separation between the resin and the electronic component due to a difference in linear expansion coefficient during injection molding can be prevented. As a result, moisture, moisture, dust, and the like can be prevented from entering the electronic component side, which also improves the reliability.

  Further, in the method of manufacturing the electronic component device, the electronic component or the circuit board is fixed by a fixing component attached to the storage body, or is held by a holding component that can protrude into the cavity. When the sealing body is injected into the cavity, the electronic component and the circuit board can be positioned well, and the electronic component device can be manufactured satisfactorily.

  In addition, as a foaming agent composition to be mixed with the thermoplastic resin as a sealing body, a foaming operation can be favorably performed in a mold cavity by using a composition composed of inorganic particles, a foaming agent and a binder component. In other words, when only the foaming agent is used as the foaming agent composition, the foaming agent may be immediately decomposed and foamed inside the cylinder where the injection molding is performed, so that the injection operation cannot be performed well. There is. On the other hand, by mixing inorganic particles, it is possible to prevent foaming inside the cylinder for injection molding and the like, and to foam well in the cavity of the mold.

  Further, when injection molding is performed using a mold, an electronic component is disposed in the cavity and the movable mold is closed, and the sealing body is injected into the cavity, and then the sealing body is foamed. In addition, by retracting the movable mold, a skin layer can be formed on the surface layer portion of the sealing body, and not only foam molding can be performed well, but also the surface appearance of the sealing body is excellent. Can be formed.

It is a longitudinal cross-sectional view of the electronic component apparatus which concerns on embodiment of this invention. (A)-(d) is a longitudinal cross-sectional view which shows the manufacturing process of the electronic component apparatus which concerns on the same embodiment, respectively. It is a longitudinal cross-sectional view of the electronic component apparatus which concerns on other embodiment of this invention. (A) is a longitudinal cross-sectional view of the electronic component apparatus which concerns on other embodiment of this invention, (b), (c) is a longitudinal cross-sectional view which shows the manufacturing process of the same electronic component apparatus. (A)-(d) is a longitudinal cross-sectional view which shows the manufacturing process of the electronic component apparatus which concerns on further another embodiment of this invention, respectively.

  Hereinafter, a method of manufacturing an electronic component device and an electronic component device according to embodiments of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, an electronic component device 1 according to an embodiment of the present invention includes a plurality of electronic components 2, a circuit board 3 on which these electronic components 2 are mounted (mounted), and the electronic component 2 Is connected to the circuit board 3 to which the circuit board 3 is attached by a connecting part 7 such as solder and is covered with a covering part 4a such as vinyl chloride, the electronic component 2, the circuit board 3 and the electric wire 4 It is comprised from the storage body 5 which accommodates the location near the part 7 inside, and the sealing body 6 with which the inside of the storage body 5 was filled (supplied). The sealing body 6 seals and covers the electronic component 2, the circuit board 3, and the portion on the connection portion 7 side of the electric wire 4. The sealing body 6 covers the electronic component 2, the circuit board 3, and the electric wire. 4 and the like on the connecting portion 7 side are integrated.

  In this embodiment, as shown in FIG. 2A, the storage body 5 is constituted by a housing made of, for example, a substantially box-shaped resin having an upper surface opened. A recess 5 a that is recessed downward is formed in a part of the upper side of the storage body 5, and the electric wire 4 is inserted from the recess 5 a and drawn out of the storage body 5.

  Here, the sealing body 6 is made of foamed thermoplastic resin as a base material. And what is also called what is called a hot-melt resin is used for the said thermoplastic resin as a base material of the sealing body 6. FIG. As the thermoplastic resin, for example, any one of polyester resin, copolymer polyester resin, polyamide resin, and polyolefin resin is used, and the thermoplastic resin is in close contact with the housing 5, the circuit board 3, and the covering portion 4 a of the electric wire 4. Good quality is used. In addition, as the thermoplastic resin, a resin other than polyester resin, copolymer polyester resin, polyamide resin, or polyolefin resin may be used. In this case as well, the housing 5, the circuit board 3, and the electric wire 4 are used. Those having good adhesion to the covering portion 4a are preferred.

Next, a method for manufacturing the electronic component device 1 will be described below.
First, as shown in FIG. 2B, a circuit board 3 on which an electronic component 2 is mounted and an electric wire 4 is connected to a housing 5 serving as a housing is disposed in the housing 5 and assembled. Attached (assembly process). In this case, although not shown, it is preferable that the circuit board 3 is fixed to the housing 5 with a fixing component such as a screw.

  Next, as shown in FIG. 2 (c), the container 5 in which the electronic component 2, the circuit board 3 and the like are assembled is disposed in the cavity 11 of the mold 10 into which the molten sealing body 6 is injected. Install (in-mold arrangement step). The mold 10 is composed of a fixed mold 10A fixed at a predetermined position, and a movable mold 10B disposed so as to be movable (for example, movable up and down) facing the fixed mold 10A, and is melted and sealed. An introduction channel 10 c for introducing the body 6 into the cavity 11 is formed. Although not shown, an injection molding apparatus (not shown) including an injection cylinder for emitting the melted sealing body 6 is connected to the introduction flow path 10c.

  Then, as shown in FIG. 2D, the melted sealing body 6 is emitted (supplied) into the housing body 5 disposed in the cavity 11. Thereafter, the sealing body 6 is cooled and solidified, so that the housing body 5 in which the electronic component 2 and the circuit board 3 are assembled and the sealing body 6 are integrated (integration step). Therefore, the manufactured electronic component device 1 is taken out from the mold 10.

  As described above, the sealing body 6 of the present embodiment uses a foamed thermoplastic resin as a base material. Moreover, what is called so-called hot melt resin is used as the thermoplastic resin as the base material of the sealing body 6 according to the present embodiment, and in the molten state, the viscosity is lower than that of a general thermoplastic resin. Is used, and the foamed thermoplastic resin introduced into the cavity 11 has a very low viscosity. For example, a general thermoplastic resin has a melt viscosity of 1000 dPa · s (decipascal · second) or more at a shear rate of 1000 (1 / s) at 200 ° C., for example. The resin needs to have a melt viscosity of 10 dPa · s or more and less than 850 dPa · s at a shear rate of 1000 (1 / s) at 200 ° C. in an unfoamed state, 10 dPa · s or more, It is preferably less than 800 dPa · s, more preferably 10 dPa · s or more and less than 720 dPa · s.

  Here, when the melt viscosity (melt viscosity when the shear rate is 1000 (1 / s) at 200 ° C.) is 850 dPa · s or more, the fluidity at the time of melting of the thermoplastic resin is deteriorated, and injection molding is performed. Although the fluidity can be increased by increasing the injection pressure, there is a growing concern that the electronic components mounted on the circuit board will be damaged. However, the thermoplastic resin having a melt viscosity of less than 850 dPa · s should be used. Thus, it is possible to reliably prevent the electronic component 2 from being damaged while ensuring good fluidity.

  Also, it is necessary to mix a thermoplastic resin and a foaming agent and foam it at the time of injection. However, the foaming agent is not mixed uniformly with the thermoplastic resin, resulting in uneven foaming or no foaming. Sometimes. In addition, the non-uniform foaming impairs the sealing performance of the formed sealing layer or impairs the adhesion between the mounted electronic component and the circuit board. The decrease in the adhesiveness of the sealing layer leads to a space between the sealing layer and the mounted electronic component and circuit board, which also reduces the sealing performance. Therefore, in the present invention, a thermoplastic resin, which is also called a so-called hot melt resin, is used which is superior in adhesiveness (adhesiveness) to a general thermoplastic resin. Further, the hot melt resin can be injection molded at a lower temperature than a general thermoplastic resin. For example, in a general thermoplastic resin, the injection molding pressure is 50 MPa to 200 MPa, but since the injection molding pressure of the thermoplastic resin of the present embodiment is less than 50 MPa, the electronic component 2 is destroyed during filling with the sealing material. There is little fear.

  The melt viscosity of the thermoplastic resin can be measured using, for example, an elevated flow tester CFT500D manufactured by Shimadzu Corporation. Moreover, the measurement conditions of melt viscosity can also be changed according to the characteristic of the thermoplastic resin to be used. For example, when the melt viscosity is small and accurate measurement is difficult, the melt viscosity can be measured by lowering the measurement temperature. As an example in that case, for example, at 180 ° C., the melt viscosity at a shear rate of 1000 (1 / s) needs to be less than 1700 dPa · s, preferably less than 1600 dPa · s. More preferably, it is less than.

  Furthermore, it is preferable that the thermoplastic resin used in the embodiment of the present invention satisfies the melt viscosity and at the same time has a specific elongation viscosity. Here, the extensional viscosity is a measure of the viscosity of the molten resin when the cracked gas generated by the decomposition of the foaming agent is sufficiently mixed with the molten thermoplastic resin to promote bubble growth. 3 shows a dynamic change in the viscosity of the molten resin with respect to the stress applied to the liquid, that is, the expansion of the bubbles. In the manufacturing method of the electronic component device of the present embodiment, it is preferable that the numerical value of the extension viscosity is larger than the predetermined melt viscosity. Specifically, at 200 ° C., the thermoplastic resin preferably has an elongational viscosity at a shear rate of 1000 (1 / s) of at least 3 times the melt viscosity, and at least 10 times the melt viscosity. More preferably, it is more preferably 100 times or more the melt viscosity.

  By setting the elongation viscosity of the thermoplastic resin within the above preferred range, when foaming, the decomposition gas generated by decomposition of the foaming agent is sufficiently mixed with the molten thermoplastic resin, and the shape of the bubbles is reduced. Inflated and kept inflated, bubbles do not break, one bubble is not connected to other bubbles surrounding it, and an independent shape can be maintained.

By satisfying the above characteristics, the foamability can be improved while improving the fluidity of the thermoplastic resin used.
Below, an example of the relationship between the melt viscosity and elongation viscosity of the thermoplastic resin used by this invention is shown.

  The elongational viscosity in the present invention can be measured based on the Cogswell theory. In the present invention, an elevated flow tester (CFT500D type manufactured by Shimadzu Corporation), die A (die nozzle diameter 0.5 mm × die length 10 mm), die B (die nozzle diameter 0.5 mm × die length 1 mm) 2 Measurement was performed using a type of die under the conditions of a measurement temperature of 200 ° C. and a shear rate of 1000 (1 / s).

  As described above, by using a foamed thermoplastic resin as the sealing body 6 that covers the electronic component 2 or the circuit board 3, a non-foamed thermoplastic resin is used as the sealing body 6. In comparison, the use amount (mass) of the thermoplastic resin can be reduced, and the weight can be reduced and the manufacturing cost can be reduced.

  The Shore D hardness of the thermoplastic resin used in the present invention is such that the Shore D hardness measured in accordance with JIS K7215 needs to be less than 60 degrees, preferably less than 55 degrees, preferably less than 50 degrees. More preferably. When the Shore D hardness exceeds 60 degrees, sealing is performed in a state in which the distortion due to the size reduction due to molding shrinkage is applied to the electronic component or the like. Further, the distortion due to the difference in linear expansion between the substrate or electronic component and the sealing resin due to a temperature change during use is not buffered, and the electronic component may be damaged or a soldered portion may be cracked.

  Furthermore, in this invention, since the thing which foamed the thermoplastic resin is used as the sealing body 6 which covers the electronic component 2 and the circuit board 3, the elasticity and contractility (cushion property) of the sealing body 6 become large. . Thereby, even when the electronic component device 1 is used in an environment such as an automobile where vibrations often occur, external vibrations are easily absorbed by the sealing body 6. As a result, external vibrations are not easily transmitted directly to the connection part 7 such as the electronic component 2, the circuit board 3, or solder, so that the electronic part 2, the circuit board 3, or the connection part 7 can be damaged by vibration due to stress cracks. This also reduces the reliability.

  A thermoplastic resin is used as the resin used for the sealing body 6. This thermoplastic resin is different from the case where it is manufactured by potting using a thermosetting resin (epoxy resin), and even when the molten thermoplastic resin is cooled and solidified, a relatively short time is required. The required time can be reduced and work efficiency is improved.

  Further, when injecting the sealing body 6 into the cavity 11 of the mold 10 in a molten state, in the molten state, a thermoplastic resin (also referred to as a so-called hot melt resin having a viscosity lower than that of a general thermoplastic resin (at 200 ° C., A thermoplastic resin having a melt viscosity of less than 850 dPa · s and a Shore D hardness of less than 60 degrees at a shear rate of 1000 (1 / s) is used, and the foam is further foamed. Low. For this reason, the injection pressure of the sealing body 6 injected from the injection molding apparatus can be small, and since the viscosity of the sealing body 6 is low, the electronic component 2 when the sealing body 6 is introduced into the cavity 11 or The pressure from the sealing body 6 acting on the circuit board 3 and the connection part 7 can be prevented from being shifted, deformed, or damaged by the position of the electronic component 2 or the circuit board 3. The reliability of the substrate 3 and the connection portion 7 is improved. In addition, the sealing body 6 extends to every corner of the housing body 5 in the space inside the cavity 11, and this also makes it possible to obtain a good product having no voids in the electronic component device 1 as a product. Thereby, it can prevent reliably that the electronic component 2, the circuit board 3, and the connection part 7 are badly affected by a water | moisture content, moisture, dust, etc.

  Further, by using a thermoplastic resin that can be injection-molded at a low temperature, which is also referred to as a so-called hot melt resin, the sealing body 6 can be injection-molded at a lower temperature than when a normal thermoplastic resin is used. Thereby, the electronic component 2, the circuit board 3, and the connection part 7 can be prevented from being damaged by heat.

  As the hot melt resin having the predetermined melt viscosity and Shore D hardness and further having a preferable elongation viscosity, particularly, a copolyester resin, a polyamide resin, and a polyolefin resin can be preferably used.

  The copolyester resin is a polyester obtained using at least a polybasic acid component and a polyhydric alcohol component, and includes at least one of at least one of a polybasic acid component residue or a polyhydric alcohol component residue. It is a thing. Examples of the polybasic acid component include aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, and aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, dodecanedioic acid, dimer acid and their anhydrides, Mention may be made of aromatic polycarboxylic acids such as merit acid and pyromellitic acid, and mixtures thereof. Examples of the polyhydric alcohol component include ethylene glycol, diethylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, trimethylolpropane, polyethylene glycol, and saturated aliphatic glycol such as polybutadiene diol, cyclohexane. Examples thereof include alicyclic glycols such as dimethanol, and mixtures thereof. Other components include saccharides such as pentaerythritol. In order to obtain a copolymer polyester resin having a predetermined melt viscosity and a preferable elongation viscosity, a long-chain aliphatic dicarboxylic acid, a saturated aliphatic glycol, a saccharide, or an aromatic polyvalent carboxylic acid is used. It is preferably used as a constituent component, and dodecanedioic acid, dimer acid, trimellitic acid, trimethylolpropane, polybutadienediol, pentaerythritol and the like can be more preferably used.

  When using the said component as said copolyester resin, it is preferable to use in the range of 1-10 mol% with respect to 100 mol% of polybasic acid components or 100 mol% of polyhydric alcohol components, respectively.

  As said polyamide resin, the polyamide resin which consists of a dimer acid and diamine can be mentioned, for example, A polyamide resin with an amine number of 3-30 and a softening point of 90 degreeC or more is preferable. Specific examples of the polyamide resin include reaction products such as dimer acid, which is a dimer of fatty acids such as soybean oil, tung oil, and tall oil, and alkyldiamines such as ethylenediamine and diethylenetriamine.

  Examples of the polyolefin resin include homopolymers and copolymers of olefins such as ethylene, propylene, and butylene, and mixtures thereof. Polyolefin resins having a softening point of 30 to 60 ° C. are preferable. The polyolefin resin may contain another copolymerizable monomer as a part of the constituent monomer. Examples of other copolymerizable monomers include vinyl ester monomers such as vinyl acetate, and alkyl acrylate monomers such as methyl acrylate, ethyl acrylate, propyl acrylate, methyl methacrylate, ethyl methacrylate, and propyl methacrylate.

  In the above embodiment, the case has been described in which the housing 5 is configured by a housing made of a substantially box-shaped resin or the like whose upper surface is opened. However, the present invention is not limited to this, and as shown in FIG. 1 is also applicable to the one further provided with a lid 15 made of resin or the like for closing the storage body (storage body main body) 5 shown in FIG. The lid body 15 and the housing body (housing body body) 5 may be provided with an introduction opening 16 through which the molten sealing body 6 is introduced.

  In the above embodiment, the case where the electronic component 2 and the circuit board 3 are arranged inside the housing 5 and the sealing body 6 is injected is described. However, the electronic body 2 and the circuit board are injected by the sealing body 6. 3 may be supplied so that the container 5 is not necessarily provided. As shown in FIG. 4 (a), when the container 5 is not provided, as shown in FIGS. 4 (b) and 4 (c), a pin or the like that can freely protrude from the mold 10 into the cavity 11 is used. Holding parts 17 and 18 are provided, and at the start of injection of the sealing body 6, the holding parts 17 and 18 protrude into the cavity 11 to hold the electronic component 2 and the circuit board 3 (for example, the four corners of the circuit board 3). It is preferable that the holding parts 17 and 18 be withdrawn from the cavity 11 at the end of injection. According to this configuration, the electronic component 2 and the circuit board 3 can be satisfactorily positioned by the holding components 17 and 18 when the sealing body 6 is injected into the cavity 11 without providing the housing body 5. The component device 1 can be manufactured satisfactorily.

  Moreover, as a foaming agent composition mixed with a thermoplastic resin as the sealing body 6, although only a foaming agent may be used, it is not restricted to this. For example, it is more preferable to use a composition comprising inorganic particles, a foaming agent and a binder component as the foaming agent composition. In this case, it is more preferable to select at least one of silica particles, calcium carbonate, and talc as the inorganic particles to be contained in the foaming agent composition.

  That is, if the foaming agent is directly mixed with the thermoplastic resin as the molding resin, when the thermoplastic resin and the foaming agent are mixed and introduced into the injection molding apparatus (not shown), Before reaching the screw compression section provided, the foaming agent is decomposed not a little in the vicinity of the supply part or the hopper mouth, and the effect of the original foaming agent is obtained in the cavity 11 of the mold 10 (10A, 10B), In other words, it may be difficult to exhibit with the sealing body 6 filled in the container 5.

  As a method for coping with this, as a foaming agent composition to be mixed with the thermoplastic resin of the sealing body 6, foaming is performed inside a cylinder for performing injection molding by using a composition composed of inorganic particles, a foaming agent and a binder component. This can be prevented and the foaming operation can be performed well in the cavity 11 of the mold 10 (10A, 10B). Thereby, the effect by the above-mentioned foaming of the sealing body 6 can be acquired favorably.

  The average particle diameter of the inorganic particles is not particularly limited, but is preferably 0.1 μm or more and 20 μm or less, more preferably 0.5 μm or more and 15 μm or less, and more preferably 1 μm or more and 10 μm or less. More preferably. When the average particle size is less than 0.1 μm, the dispersibility is poor and the impact strength of the foamed molded product (sealed body 6) may be reduced. When the average particle diameter exceeds 20 μm, the surface appearance of the foamed molded body (sealed body 6). May decrease.

  The inorganic particles may be surface-treated with a reactive compound such as a silane coupling agent, a titanate coupling agent, or an organosiloxane as necessary. In particular, a silane coupling agent can be preferably used. For example, pinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-menole. Examples include captopropyltrimethoxysilane.

The silica particles are mainly composed of silicon dioxide represented by SiO ₂ , and are roughly classified into two types, that is, wet method silica and dry method silica, depending on the production method. Can do. The oil absorption of the silica particles measured with J1SK5101 is preferably 200 ml / 100 g or less, more preferably 150 ml / 100 g, and even more preferably 100 ml / 100 g. When the oil absorption exceeds 200 ml / 100 g, the binder component is absorbed by the silica particles when the foaming agent composition is processed into pellets, and the amount of binder component added must be increased. When the amount of the binder component is increased, the handling of the pellet of the foaming agent composition may be deteriorated, or the appearance of the obtained foamed molded body (sealed body 6) may be impaired.

  Further, the bulk specific gravity of silica particles measured by J1S K6220 is preferably 0.2 or more, more preferably 0.3 or more, and further preferably 0.4 or more. When the bulk specific gravity is less than 0.2, the bulk of the silica particles is too high, which may cause problems in workability when the foaming agent composition pellets are used, and the foaming agent composition pellets themselves are hard. May be insufficient, may be fragile when mixed with a molding resin, and may have poor molding stability.

  Further, the blending ratio of the inorganic particles in the pellet of the foaming agent composition needs to be 30 to 80% by mass, preferably 35 to 75% by mass, and more preferably 40 to 60% by mass. . Thereby, it is possible to prevent foaming inside the cylinder for injection molding and the like, and to perform the foaming operation well in the cavity 11 of the mold 10 (10A, 10B).

In addition, as the foaming agent, an inorganic foaming agent or an organic foaming agent known per se can be used. Specific examples of blowing agents include sodium bicarbonate, ammonium bicarbonate, sodium carbonate, ammonium carbonate, azodicarbonamide, N, N′-dinitrosopentamethylenetetramine, dinitrosotephthalamide, azobisisobutyronitrile, azo Examples thereof include barium dicarboxylate, 4,4′-oxybisbenzenesulfonyl hydrazide, toluenesulfonyl hydrazide, and mixtures thereof. However, it is not preferable that water vapor is generated as a decomposition gas at the time of foaming because the electronic component 2 is affected by moisture. Therefore, what generates inert gas, such as nitrogen gas, as decomposition gas is preferable. As such a foaming agent, azodicarbonamide, 4,4'-oxybisbenzenesulfonyl hydrazide, or the like can be used.

  Also, in selecting a foaming agent, it is important to fully consider the decomposition temperature of the foaming agent. When the foaming agent reaches a predetermined temperature, the foaming agent is decomposed and decomposed gas is generated and foamed. However, as a thermoplastic resin forming the sealing layer 6, the foaming agent has a predetermined melt viscosity characteristic at a predetermined temperature. It is necessary to use what has, but for example, when molding is performed by setting a specific resin temperature at the time of injection in injection molding to melt the thermoplastic resin, the foaming agent contained is sufficiently decomposed and decomposed It is important that gas is generated. That is, the specific resin temperature is preferably 0 to 70 ° C. higher than the decomposition temperature of the foaming agent, more preferably 5 to 60 ° C., and further preferably 10 to 50 ° C. When the resin temperature is lower than the decomposition temperature of the foaming agent, the foaming agent is not decomposed and the thermoplastic resin cannot be foamed. When the resin temperature is higher than (decomposition temperature of the foaming agent + 70 ° C.), the thermoplastic resin is thermally deteriorated, which is not preferable.

  For example, when a copolyester is used as the thermoplastic resin, the resin temperature is 210 to 260 ° C., and when the azodicarbonamide (decomposition temperature: 200 to 220 ° C.) is used in combination as a foaming agent, the thermoplastic resin is used. The melt viscosity, foamability, adhesion, sealing properties, and adhesion to the wiring coating material can be satisfied in a well-balanced manner, and can be particularly preferably used.

  The average particle diameter of the foaming agent is not particularly limited, but the average particle diameter is preferably 1 to 40 μm, and more preferably 2 to 30 μm. Further, in the particle size distribution of the foaming agent, it is particularly effective when it substantially contains fine particles having a particle diameter of 4 μm or less, and further effective when it substantially contains fine particles having a particle diameter of 2 μm or less.

  The blending ratio of the foaming agent in the pellet of the foaming agent composition needs to be 3 to 30% by mass, preferably 5 to 25% by mass, and more preferably 10 to 20% by mass. When the blending ratio is less than 3% by mass, the amount of pellets added to the emulsifier composition increases when the foam is molded, so that the impact strength of the resulting foam molded body (sealing body 6) decreases. There are things to do. On the other hand, when it exceeds 30 mass%, in order to obtain a predetermined foaming performance, it is necessary to reduce the amount of pellets added to the foaming agent composition, and this may result in poor molding stability. In addition, swirl marks and apatial irregularities are often seen, and the surface appearance may be inferior.

  Examples of the binder component used in the present invention include water, ethanol, ethylene glycol, glycerin, liquid paraffin, paraffin wax, polyolefin wax, polyalkylene glycol terminal modified product, phosphate ester or phosphite ester, higher fatty acid ester , One or more compounds selected from the group consisting of higher fatty acid metal salts, higher fatty acid bisamides, and higher aliphatic amines. In particular, paraffin wax, polyolefin wax, higher fatty acid ester, higher fatty acid metal salt, and higher fatty acid bisamide can be suitably used.

  Moreover, when not using the said foaming agent composition but using a foaming agent independently, an inorganic particle can be contained further. The type of inorganic particles is not particularly limited, and examples thereof include talc, calcium carbonate, silica, mica, hydrotalcide and the like. Among these, talc and calcium carbonate are particularly preferable because they are effective in promoting the decomposition of the foaming agent and the generation of closed cells having fine and uniform cell diameters.

  Further, the resin forming the sealing layer 6 may also contain thermally conductive particles. The kind of the heat conductive particles is not particularly limited, and examples thereof include natural graphite, carbon black, ketjen black, alumina, silica, boron nitride, silicon carbide, and aluminum nitride. Of these, carbon and other conductive materials are not preferable because they cause problems such as short circuits in the circuit board 3 to be sealed. On the other hand, non-conductive and heat conductive materials such as alumina can be used particularly preferably. By performing such a prescription, when the electronic component 2 generates heat, heat can be effectively dissipated. When such prescription is difficult, sealing can be performed by joining a heat sink to the circuit board 3 and exposing the other end of the heat sink.

  In the above embodiment, when the sealing body 6 is injected into the cavity 11 of the mold 10 in a molten state, and thereafter, in any period when the sealing body 6 foams in the cavity 11, As shown in FIGS. 2C and 2D, the case where the movable mold 10 </ b> B is always aligned with the fixed mold 10 </ b> A and held in the closed state is described, but the present invention is not limited to this.

  For example, as shown in FIG. 5C, when the sealing body 6 is injected into the cavity 11, the movable mold 10B is kept closed in accordance with the fixed mold 10A. As shown in (d), when the sealing body 6 is foamed, the movable mold 10B is retracted (in the case shown in FIG. 5 (d), raised) to perform a so-called injection core back operation.

  Thus, when the sealing body 6 is foamed, the movable mold 10B is retracted so that the foamed gas can be dissipated from the surface portion of the sealing body 6 to the outside. The skin layer 6a can be formed on the portion, and not only foam molding can be performed satisfactorily but also the sealing body 6 having an excellent surface appearance can be formed.

  Moreover, in the said embodiment, although the case where the circuit board 3 and the electric wire 4 were provided in the electronic component apparatus 1 was described, it is not restricted to this, The circuit board 3 and the electric wire 4 are not provided. Of course, the electronic component device 1 can be satisfactorily manufactured by the same manufacturing method.

The method of manufacturing an electronic component device according to the present invention solves the above-described problem, and supplies a molten sealing body so as to enclose the electronic component so that the electronic component is integrated with the sealing body. And the sealing body is foamed in the integration step by adding a foaming agent composition to a thermoplastic resin, and the thermoplastic resin is a polyamide resin or a polyester resin, a temperature 200 ° C., shear speed 1 000 (1 / s) a melt viscosity at ηA is 10dPa · s or more and less than 850dPa · s, the temperature 200 ° C., at a shear rate of 1000 (1 / s) The relationship (ηB / ηA) with the extensional viscosity ηB is 3 times or more .

The electronic component device of the present invention has an electronic component and a sealing body that covers the electronic component,
The sealing body is formed of a foamed thermoplastic resin, the thermoplastic resin is a polyamide resin or a polyester resin, the melt viscosity at 200 ° C., shear speed 1 000 (1 / s) ηA Is 10 dPa · s or more and less than 850 dPa · s , and the relationship (ηB / ηA) with the elongational viscosity ηB at a temperature of 200 ° C. and a shear rate of 1000 (1 / s) is 3 times or more .

Further, the thermoplastic resin of the present invention is a polyamide resin or a polyester resin, a temperature 200 ° C., shear speed 1 000 (1 / s) a melt viscosity at ηA is 10dPa · s or more, less than 850dPa · s There, the temperature 200 ° C., the relationship between the elongational viscosity ItaB at a shear rate of 1000 (1 / s) (ηB / ηA) , characterized in that at least three times.

Claims (12)

Supplying a melted sealing body so as to enclose the electronic component, and having an integration step of covering the electronic component so as to be integrated with the sealing body,
The sealing body is obtained by adding a foaming agent composition to a thermoplastic resin and foaming in the integration step. When the thermoplastic resin has a shear rate of 1000 (1 / s) at 200 ° C. The melt viscosity is 10 dPa · s or more and less than 850 dPa · s, and the Shore D hardness is less than 60 degrees.   2. The method of manufacturing an electronic component device according to claim 1, wherein the thermoplastic resin has an extensional viscosity higher than the melt viscosity.   3. The method of manufacturing an electronic component device according to claim 2, wherein the thermoplastic resin has an extensional viscosity of 3 times or more of a melt viscosity. Storing the electronic component in a storage body;
The said integration process WHEREIN: The said sealing body is supplied in the molten state to the storage body which accommodated the said electronic component, and the said electronic component is covered, The any one of Claims 1-3 characterized by the above-mentioned. Manufacturing method of electronic component device.   The electronic component is disposed in a cavity of a mold for injection molding in the integration step, and the sealing body is injected into the cavity in a molten state. The manufacturing method of the electronic component apparatus of description.   An electronic component or a circuit board on which the electronic component is mounted is fixed by a fixing component attached to a housing for storing the electronic component, or protrudes into a mold cavity at the start of injection of the sealing body and the electronic component 6. The method of manufacturing an electronic component device according to claim 5, wherein at least one of the component and the circuit board is held and held by a holding component that exits from the cavity at the end of injection.   The said foaming agent composition consists of an inorganic particle, a foaming agent, and a binder component, The manufacturing method of the electronic component apparatus of any one of Claims 1-6 characterized by the above-mentioned. The mold is composed of a fixed mold and a movable mold,
In a state where electronic parts are arranged in the cavity and the movable mold is closed, the sealing body is injected into the cavity,
6. The method of manufacturing an electronic component device according to claim 5, wherein the movable mold is moved backward when the sealing body is foamed. An electronic component and a sealing body covering the electronic component;
The sealing body is formed of a foamed thermoplastic resin;
An electronic component characterized in that the thermoplastic resin has a melt viscosity of 10 dPa · s or more and less than 850 dPa · s at a shear rate of 1000 (1 / s) at 200 ° C. and a Shore D hardness of less than 60 degrees. apparatus. A storage body for storing the electronic component therein;
The electronic component device according to claim 9, wherein the sealing body is disposed in a state in which the electronic component is covered in the storage body.   The electronic component is mounted on a circuit board, an electric wire is connected to the electronic component or the circuit board at a connecting portion, and the connecting portion side of the electric wire is also covered with the sealing body. The electronic component device according to 10.   The electronic component device according to claim 9, wherein the sealing body includes a foaming agent composition having inorganic particles, a foaming agent, and a binder component.

Images