JPH10117116A - Method for sealing vibrator or resonator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a gap from being formed between sealing resin and a lead terminal and obtain high reliability through a simple process by forming the adhesion part of a hot-melt type adhesive between the lead terminal and sealing resin made of thermoplastic resin. SOLUTION: To manufacture a vibrator, an internal element 2 to which lead terminals 4a and 4b as insert members are mounted in a metal mold and parts of the lead terminals which are close to the internal element 2 are coated thinly with a heat-resisting hot-melt type adhesive which is dissolved in a solvent. Then injection molding is performed by using liquid crystal resin. The liquid crystal resin in use is a thermotropic liquid crystal polyester containing resin components consisting of constituent units derived from 4-hydroxy benzoic acid, etc., and glass fiber. The injection molding is carried out so that molten resin flows on the plane of an electrode 3a, and consequently a sufficient vibration space can be secured at right angles to the flowing direction, i.e., in the space above the electrode 3a by volumetric shrinkage characteristics of the thermotropic liquid crystal resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component having a gap for securing a vibration space between an internal element and a sealing resin, such as a piezoelectric vibrator such as a quartz oscillator or a ceramic oscillator. The sealing method.

[0002]

2. Description of the Related Art Resonators and resonators are widely used in filters and various electronic and electrical devices as sub-standards of frequency or time, and there is a demand for improvement in reliability, production efficiency, and cost reduction. . The vibrator and the resonator are configured such that electrodes are arranged on a substrate (internal element) such as ceramic or quartz, and an electric signal of a specific frequency is transmitted or passed when an electric signal is applied. . In such resonators and resonators, it is necessary to protect the internal elements from external influences such as mechanical and thermal shocks and corrosion due to an external atmosphere. Further, since the internal element mechanically vibrates to exhibit its original function, a space that does not suppress the vibration is required.

[0003] In view of these necessities, in the production of a vibrator and a resonator, it is necessary to provide an electrode for an internal element, separately prepare a support portion, enclose it in a hollow cover (package), or secure an internal space. The resin sealing is performed after the above-mentioned treatment is performed. As a way to use the package,
For example, JP-A-6-132759 discloses a method in which an internal element is covered with a package and then sealed with a resin. However, this method is very effective in securing internal space because of the use of a package, but on the other hand, it is difficult to reduce the size and secure a sufficient mounting area, and to reduce the cost of the package itself. Due to limitations, it is also difficult to meet the demand for lower prices. In addition, as a method using resin sealing, there is a method in which wax or the like is applied to an internal element and then resin sealing is performed, and after sealing molding, the wax is removed to secure a hollow portion. However, in this method, an adhesive resin is used in order to prevent a gap between the lead terminal and the sealing resin from invading moisture or gas, and the resin used for this purpose has an adhesive property to metal. Since it is limited to a thermosetting resin such as an epoxy resin having the following properties, it is difficult to reduce the cost by high-speed cycle molding. If a thermoplastic resin is used here, high-speed cycle molding is possible, but since there is no adhesiveness to metal, moisture and gas, etc., between the lead terminals and the sealing resin due to shrinkage of the resin during solidification. As a result, there is a gap into which the lead terminals enter, and the exposed boundary portion of the lead terminal must be sealed by secondary processing. As a result, it is difficult to reduce the cost.

[0004]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problems. In other words, we developed a method to cover the internal element directly with a thermoplastic resin and obtain a highly reliable product without performing secondary processing. It is an object of the present invention to provide a method of sealing a resonator or a resonator.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a method of sealing a resin by applying a hot melt type adhesive to an arbitrary position of a lead terminal in a sealing molding using a thermoplastic resin. Is performed. That is, the present invention provides an internal element, a lead terminal having one end connected to the internal element, and a resonator or resonator made of a sealing resin that covers the internal element together with a connection portion with the lead terminal. (1) By using a thermoplastic resin as the sealing resin, a gap is formed between the internal element and the sealing resin by utilizing shrinkage during solidification of the resin, and (2) an arbitrary position of the lead terminal A vibrator or a resonator characterized in that a hot-melt type adhesive is applied in advance to the lead terminal and the adhesive is melted by the heat of the sealing resin to form an adhesive portion between the lead terminal and the sealing resin. The sealing method. Further, the present invention relates to a method of sealing a vibrator or a resonator, wherein the thermoplastic resin is a thermotropic liquid crystal resin.

Hereinafter, the present invention will be further described. Usually, the thermoplastic resin shows a certain degree of volume shrinkage in the process of melting and cooling and solidifying, though the degree varies. Therefore, the thermoplastic resin used in the present invention is not particularly limited, and any resin can be used as long as injection molding is possible. Preferably, polyamide-based resins such as nylon-6, -66, -46 and polyphthalamide; polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycyclohexylene terephthalate from the viewpoint of strength, heat resistance, chemical resistance and the like. Polyester resin such as;
Polycarbonate resins; polyphenylene oxide resins; polyphenylene sulfide resins; polyketone resins; polysulfone resins and thermotropic liquid crystal polyester resins. When used for a package of a semiconductor element or the like, a polyamide resin, a polyester resin, a phenylene sulfide resin, a thermotropic liquid crystal resin, etc., which are excellent in heat resistance and moldability, are particularly preferable.

Among these, thermotropic liquid crystal resins, for example, thermotropic liquid crystal polyester resins, are the most preferable because they exhibit anisotropic shrinkage and a large shrinkage in the direction perpendicular to the flow of the resin during molding. is there.
The thermotropic liquid crystal resin referred to in the present invention is a polymer that exhibits optical anisotropy when melted and has thermoplasticity. As described above, a polymer that exhibits optical anisotropy at the time of melting exhibits a property that the polymer molecular chains take a regular parallel arrangement in a molten state. The properties of the optically anisotropic molten phase can be confirmed by a normal polarization inspection method using a crossed polarizer. Examples of the liquid crystal resin include liquid crystalline polyester, liquid crystalline polycarbonate, liquid crystalline polyesterimide and the like, and specifically, (whole) aromatic polyester, polyesteramide, polyamideimide, polyestercarbonate, polyazomethine and the like. A thermotropic liquid crystal resin generally has an elongated and flat molecular structure, and has high rigidity along a long chain of the molecule. The thermotropic liquid crystal resin used in the present invention also includes a polymer in which a part of one polymer chain is composed of a polymer segment forming an anisotropic molten phase. Further, a composite of a plurality of thermotropic liquid crystal resins is also included.

[0008] Representative examples of the monomer constituting the thermotropic liquid crystal resin include (A) at least one kind of aromatic dicarboxylic acid, (B) at least one kind of aromatic hydroxycarboxylic acid compound,
(C) at least one aromatic diol compound;
(D) at least one of (D ₁ ) aromatic dithiol, (D ₂ ) aromatic thiophenol and (D ₃ ) aromatic thiol carboxylic acid compound, and (E) at least one of aromatic hydroxylamine and aromatic diamine compound. One or more aromatic compounds may be mentioned. These may be used alone, but in many cases (A) and (C); (A) and (D);
(A), (B) and (C); (A), (B) and (E); or (A), (B), (C) and (E), and the like.

The aromatic dicarboxylic acid compound (A) includes terephthalic acid, 4,4'-biphenyldicarboxylic acid, 4,4'-terphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 1,4- Naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, diphenyl ether-4,4'-dicarboxylic acid, diphenoxyethane-
4,4'-dicarboxylic acid, diphenoxybutane-4,4'-
Dicarboxylic acid, diphenylethane-4,4'-dicarboxylic acid, isophthalic acid, diphenylether-3,3'-dicarboxylic acid, diphenoxyethane-3,3'-dicarboxylic acid, diphenylethane-3,3'-dicarboxylic acid, 1,6
Aromatic dicarboxylic acids such as naphthalenedicarboxylic acid, or chloroterephthalic acid, dichloroterephthalic acid, bromoterephthalic acid, methylterephthalic acid, dimethylterephthalic acid, ethylterephthalic acid, methoxyterephthalic acid,
Alkyl, alkoxy or halogen substituents of the above aromatic carboxylic acids represented by ethoxy terephthalic acid and the like.

(B) The aromatic hydroxycarboxylic acid compounds include aromatic hydroxycarboxylic acids such as 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid and 6-hydroxy-1-naphthoic acid. Carboxylic acids, or 3-methyl-4-hydroxybenzoic acid,
3,5-dimethyl-4-hydroxybenzoic acid, 2,6-dimethyl-4-hydroxybenzoic acid, 3-methoxy-4-
Hydroxybenzoic acid, 3,5-dimethoxy-4-hydroxybenzoic acid, 6-hydroxy-5-methyl-2-naphthoic acid, 6-hydroxy-5-methoxy-2-naphthoic acid, 2-chloro-4-hydroxybenzoic acid Acid, 3-chloro-4-hydroxybenzoic acid, 2,3-dichloro-4-hydroxybenzoic acid, 3,5-dichloro-4-hydroxybenzoic acid, 2,5-dichloro-4-hydroxybenzoic acid, 3- Bromo-4-hydroxybenzoic acid, 6-hydroxy-5-chloro-2-naphthoic acid, 6-hydroxy-
7-chloro-2-naphthoic acid, 6-hydroxy-5,7
Alkyl-, alkoxy-, or halogen-substituted aromatic hydroxycarboxylic acids such as -dichloro-2-naphthoic acid.

(C) As aromatic diols, 4,4'-dihydroxybiphenyl, 3,3'-dihydroxybiphenyl, 4,4'-dihydroxyterphenyl, hydroquinone, resorcinol, 2,6-naphthalenediol, 4,4 '
-Dihydroxydiphenyl ether, bis (4-hydroxyphenoxy) ethane, 3,3'-dihydroxydiphenyl ether, 1,6-naphthalenediol, 2,2'-
Bis (4-hydroxyphenyl) propane, aromatic diol such as bis (4-hydroxyphenyl) methane, or chlorohydroquinone, methylhydroquinone, tert-
Butylhydroquinone, phenylhydroquinone, methoxyhydroquinone, phenoxyhydroquinone, 4-
Alkyl, alkoxy or halogen-substituted aromatic diols such as chlororesorcin and 4-methylresorcin.

Examples of (D ₁ ) aromatic dithiol include benzene-1,4-dithiol, benzene-1,3-dithiol, 2,6-naphthalene-dithiol, and 2,7-naphthalene-dithiol. (D ₂ ) Examples of the aromatic thiophenol include 4-mercaptophenol, 3-mercaptophenol, and 6-mercaptophenol. (D ₃ ) Examples of the aromatic thiol carboxylic acid include 4-mercaptobenzoic acid, 3-mercaptobenzoic acid, 6-mercapto-2-naphthoic acid, and 7-mercapto-2-naphthoic acid.

(E) As the aromatic hydroxylamine or aromatic diamine compound, 4-aminophenol, N-methyl-4-aminophenol, 1,4-phenylenediamine, N-methyl-1,4-phenylenediamine , N, N'-dimethyl-1,4-phenylenediamine, 3-aminophenol, 3-methyl-4-aminophenol, 2-chloro-4-aminophenol, 4-amino-1-naphthol, 4-amino- 4'-hydroxybiphenyl, 4-amino-4'-hydroxydiphenyl ether, 4-amino-4'-hydroxydiphenylmethane, 4-amino-4'-hydroxydiphenyl sulfide, 4,4'-diaminodiphenyl sulfide (thiodianiline), , 4'-diaminodiphenyl sulfone,
2,5-diaminotoluene, 4,4′-ethylenedianiline, 4,4′-diaminodiphenoxyethane, 4,4′-diaminodiphenylmethane (methylenedianiline),
4'-diaminodiphenyl ether (oxydianiline) and the like.

The thermotropic liquid crystal resin may be used alone, but preferably contains an inorganic or organic filler. Usually, the amount of the inorganic or organic filler is
0 to the total amount of thermotropic liquid crystal resin and filler
It is in the range of 90% by weight, preferably 10-80% by weight, more preferably 20-60% by weight. The composition of the filler
It can be performed according to a conventionally known method. Of the inorganic or organic fillers, inorganic fillers are particularly important, and are often used to improve the processability of the thermotropic liquid crystal resin and the properties of molded articles. As the inorganic filler, conventionally known molybdenum disulfide, talc, mica, clay, sericite, calcium carbonate, calcium silicate,
Examples include silica, alumina, aluminum hydroxide, graphite, amorphous carbon, potassium titanate, glass fiber, carbonated fiber, and various whiskers.

In the present invention, in order to improve physical properties in practical use, various additives can be added to the polymer in addition to the inorganic or organic filler to the thermotropic liquid crystal resin. Examples of such additives include conventionally known stabilizers, antioxidants, ultraviolet absorbers, pigments, dyes, and modifiers.

As long as the effects of the present invention are exhibited,
Thermotropic liquid crystal resin to other thermoplastic resins, for example, polyolefin, polyvinyl chloride, polyvinylidene chloride, PA-6, PA-66, PA-46 and other aliphatic polyamides, polyphthalamide, PET, PBT and other polyesters, Polyarylate (PAR), Polyketone (P
EK), polyetheretherketone (PEEK), polyethersulfone (PES), polyimide (P
I), polyamide imide (PAI), polyether imide (PEI), polyphenylene sulfide (PP
In addition to S), polysulfone (PSF) and the like, elastomers such as natural rubber and synthetic rubber can be further compounded. These resins are not essential components in the present invention, but the types and amounts thereof can be appropriately selected according to the purpose.

The hot-melt adhesive used in the present invention is an adhesive resin made of a non-volatile thermoplastic material which does not substantially contain water or a solvent and is solid at room temperature. Generally, it is composed of a base polymer, a tackifier resin, a wax, an additive such as an antioxidant, and the like, and is often classified according to the type of the base polymer. The material used in the present invention is not particularly limited as long as it can bond the lead terminal and the thermoplastic resin to be injection-molded. For example, polyethylene,
Ethylene-vinyl acetate copolymer resin, ethylene-ethyl acrylate copolymer resin, ethylene-isobutyl acrylate copolymer resin, polyamide, polyester, butyral, polyvinyl acetate copolymer, cellulose derivative, polymethyl methacrylate And a hot-melt adhesive having a base polymer of a resin of a polyether type, a polyvinyl ether type, a polyurethane type, a polycarbonate type or the like, or a mixture thereof. Particularly when heat resistance is required, polyamide-based, polyester-based,
A hot-melt adhesive using a polyurethane-based or polycarbonate-based resin or a mixture thereof as a base polymer is preferable.

The hot-melt type adhesive to be applied can be in any shape such as a film, a thread, a bar, and a dot. Therefore, as a method of application, it is also possible to use a solvent, but it is preferable to apply it by melting it because it is a hot melt adhesive. Specifically, a normal hot melt coater (a roll coater, an extrusion coater, a slot orifice coater, a curtain coater, etc.), a hot melt type applicator such as a hot melt applicator, or a hot melt melted adhesive is used. And dipping in a mold adhesive.

The vibrator or the resonator referred to in the present invention includes all electronic parts utilizing mechanical vibration due to a piezoelectric effect or the like exhibited by an internal element or surface acoustic waves generated thereby. In addition to oscillators and resonators,
Examples include a ceramic filter, a trap element, and a discriminator. Since the internal element is a central member that generates vibration of these electronic components, it is necessary to secure a vibration space around the internal element so as not to suppress the vibration. In addition, two lead wires or lead terminals according to the present invention are usually connected to the vibration electrode. In the encapsulation molding, since the entire internal element is covered with a thermoplastic resin, the lead wire is exposed to the outside at any part of the surface of the encapsulation resin for connection with an external device. As described above, the thermoplastic resin usually shows a constant volume shrinkage when solidified after being melted.However, a vibration space is secured around the internal element, and at the same time, the lead wire and the resin exposed to the outside are removed. A gap is likely to be formed at the boundary of. Since moisture or the like may intrude from the outside through the gap, it is necessary to apply a hot-melt type adhesive to a portion where a gap into which moisture or the like easily enters is likely to form an adhesive portion. The hot melt type adhesive may be applied to any position of the lead terminal, but is usually applied to a portion of the lead terminal close to the internal element.

In the encapsulation molding used in the present invention, a hot-melt type adhesive is first applied to an arbitrary position of a lead terminal by the above-described method, and then placed in a mold and heated and melted in the mold. The molded insert is obtained by injecting the thermoplastic resin thus obtained. The injection molding can be performed according to a conventional method for insert molding. An ordinary injection molding machine is used as the molding machine. The molding temperature (the temperature of the heating cylinder of the injection molding machine) is preferably a temperature sufficient to melt the thermoplastic resin to be injected and to melt the hot melt adhesive. From this viewpoint, the combination of the thermoplastic synthetic resin and the hot melt adhesive is determined. As a guide, the molding temperature of the thermoplastic resin is higher than the melting temperature of the hot melt adhesive by 30 ° C. or higher, preferably 70 ° C. or higher, more preferably 100 ° C. or higher, but is set to 200 ° C. or lower. For example, the injection molding conditions of the thermotropic liquid crystal resin are as follows.
° C, mold temperature 60-170 ° C, more preferably 60-1
It can be appropriately selected from a range of 30 ° C., an injection pressure of 100 to 3,000 kg / cm ² , and an injection speed of 5 to 1,000 mm / sec. At the time of insert molding by injection molding, the hot-melt adhesive is melted by the heat of the thermoplastic resin that has been melted by heating, whereby the thermoplastic resin and the lead terminals can be bonded by the hot-melt adhesive. In this method, it is necessary that the molding temperature of the thermoplastic resin, that is, the temperature of the molten resin is sufficiently higher than the fusion bonding temperature of the hot melt adhesive as described above.

In the sealing method of the present invention, the thermoplastic resin as the sealing resin is adhered or adhered to ceramic, crystal, metal and metal oxide which are frequently used as the internal element of the vibrator or the resonator. Since the resin does not have the property, the internal element and the sealing resin are easily separated from each other due to the volume shrinkage of the resin when the sealing resin is solidified in the sealing molding, and a gap is formed between the two. At the same time, due to the heat of the molten resin,
Since the hot-melt adhesive applied to the lead terminals is melted to develop an adhesive force, a gap serving as a path through which moisture, gas, and the like intrudes from the outside is sealed, and high reliability can be secured. .

As described above, the thermotropic liquid crystal resin has anisotropy in the shrinkage rate during molding due to its characteristics, and particularly has a large shrinkage rate in a direction perpendicular to the flow of the resin during molding.
The voids formed by volume shrinkage occurring during the solidification of the resin in the encapsulation molding are larger than those of other thermoplastic resins, and therefore can widely cope with the vibration mode of the internal element. For example, when sealing is performed using a thermotropic liquid crystal resin, if the vibration space to be secured is a flat surface, injection molding is performed so that the molten resin flows parallel to the flat surface. As a result, the volume shrinkage increases in the direction perpendicular to the flow direction, that is, in the thickness direction, so that a sufficient space can be secured on a plane. Since the internal elements such as the vibrator and the like are usually in the form of a flat plate in many cases, the injection space as described above can easily secure a vibration space.

[0023]

Embodiments of the present invention will be described below in detail with reference to the drawings.

1 is a partially cutaway front view showing the structure of a vibrator according to an embodiment of the present invention, and FIG. 2 is a right side view of the vibrator shown in FIG. The vibrator 1 includes electrodes 3a, 3
b, and a lead terminal 4 having one end connected to the electrodes 3a and 3b and the other end exposed to the outside of the internal element 2.
a, 4b and a sealing resin 5 for covering the internal element 2 together with the electrodes 3a, 3b and a part of the lead terminals 4a, 4b. Further, between the sealing resin 5 and the surfaces of the lead terminals 4a and 4b, an adhesive 6 made of a hot-melt type adhesive is provided.
a, 6b are formed, and a gap 7 for securing a vibration space of the internal element 2 is formed.

In manufacturing the vibrator, first, the internal element 2 to which the lead terminals 4a and 4b as insert members are connected is placed in a mold, and a portion of the lead terminal adjacent to the internal element 2 is exposed to a solvent. A commercially available heat-resistant hot-melt adhesive dissolved was thinly applied. Thereafter, injection molding was performed using a liquid crystal resin by a conventional method. The liquid crystal resin used was
A thermotropic liquid crystal polyester containing a resin component consisting of a structural unit derived from 4-hydroxybenzoic acid, 4,4'-dihydroxybiphenyl, terephthalic acid and isophthalic acid, and 25% by weight of glass fiber. The resin component had a melting point of 380 ° C. determined by DSC, and exhibited optical anisotropy when melted by heating. The injection molding is performed so that the molten resin flows on the plane of the electrodes 3a and 3b. As a result, in the direction perpendicular to the flow direction, that is, in the upper space of the electrodes 3a and 3b, the volume shrinkage specific to the thermotropic liquid crystal resin is caused. A sufficient vibration space could be secured. Further, the hot melt adhesive was melted by the heat of the molten resin, and the bonded portions 6a and 6b were formed.

The sealing method of the present invention is characterized in that internal elements can be reliably sealed and voids can be formed at the same time only by adding work of applying a hot melt type adhesive to ordinary insert molding. There are features. That is, polyester which does not show adhesion or adhesiveness to the internal element 2,
By using polyamide, polyphenylene sulfide, or the like, voids 7 are formed due to volume shrinkage at the time of resin solidification in sealing molding. However, in this state, a gap is also formed between the sealing resin 5 and the lead terminals 4a and 4b, and the invasion of moisture or gas from the outside is caused.
b. Apply a hot-melt type adhesive to an arbitrary position, melt the hot-melt type adhesive by resin heat at the time of encapsulation molding to develop adhesiveness, and form gaps by forming the bonded portions 6a and 6b. Seal. In order to make the gap 7 formed between the sealing resin 5 and the internal element 2 larger, the shrinkage at the time of solidification of the resin shows anisotropy. It is desirable to use a resin that is larger than the ratio, for example, a thermotropic liquid crystal resin, so that it is possible to cope with various vibration states of the internal element.

[0026]

According to the present invention, by forming an adhesive portion with a hot-melt type adhesive between a lead terminal and a sealing resin made of a thermoplastic resin, a problem has conventionally been encountered in sealing molding. Since the formation of a gap between the sealing resin and the lead terminal can be prevented, and the gap formed when the resin is solidified in the sealing molding can be used as an internal space for the internal element to vibrate. In addition, it is possible to produce a highly reliable vibrator and resonator with simple steps.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view of an example of a vibrator of the present invention.

FIG. 2 is a right side view of the vibrator shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Oscillator 2 Internal element 3a, 3b Electrode 4a, 4b Lead terminal 5 Sealing resin 6a, 6b Adhesive part 7 Air gap

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H03H 9/17 H03H 9/17 A // B29L 31:34

Claims (2)

[Claims] In the manufacture of a resonator or a resonator made of an internal element, a lead terminal having one end connected to the internal element, and a sealing resin covering the internal element together with a connection to the lead terminal, ) By using a thermoplastic resin as the sealing resin, a gap is formed between the internal element and the sealing resin by utilizing shrinkage of the resin during solidification, and (2) an arbitrary position of the lead terminal is formed. A vibrator or a resonator characterized in that a hot melt type adhesive is applied in advance, and the adhesive is melted by the heat of the sealing resin to form an adhesive portion between the lead terminal and the sealing resin. Sealing method. 2. The method according to claim 1, wherein the thermoplastic resin is a thermotropic liquid crystal resin.