JP7038260B2 - An electronic component containing a liquid crystal resin composition and a molded product of the liquid crystal resin composition. - Google Patents

Description

The present invention relates to a liquid crystal resin composition and an electronic component including a molded product of the liquid crystal resin composition.

The liquid crystal resin is a thermoplastic resin having excellent dimensional accuracy, fluidity, and the like. Due to these characteristics, liquid crystal resins have been conventionally used as materials for various electronic components.

In particular, with the recent increase in the performance of electronic devices, there is a demand for higher heat resistance of connectors (improvement of productivity by mounting technology), higher density (multi-core), and miniaturization, and the above liquid crystal resin A liquid crystal resin composition reinforced with glass fiber is adopted as a connector material by taking advantage of the above-mentioned characteristics.

However, in recent years, connectors have become lighter, thinner, shorter and smaller, and due to insufficient rigidity due to insufficient wall thickness of molded products and internal stress due to metal terminal inserts, warpage deformation occurs after molding and during reflow heating, and soldering to the substrate. There is a problem of failure. That is, in the conventional strengthening using only glass fibers, there is a problem that if the amount of glass fibers added is increased in order to increase the rigidity, the thin-walled portion is not filled with the resin, or the insert terminal is deformed by the pressure during molding.

In order to solve the problem of warpage deformation, a molding method is devised, and a specific plate-like filler is proposed from the material aspect. That is, in the case of ordinary connectors (electronic parts) that are often found in the market, it is possible to control the dimensional accuracy and warpage of the product by designing the gate position and design so as to maintain symmetry during molding. Further, by using the conventionally proposed low warp material, a product with less warp deformation is obtained.

However, with the increasing complexity of the shapes of electronic components in recent years, it is required to provide asymmetric electronic components that are not symmetric with respect to any of the XY axis plane, the YZ axis surface, and the XZ axis surface of the molded product. ing. As a typical example of such an asymmetric electronic component, a connector for a memory module having a latch structure (having claws for fixing at both ends) such as a DDR-DIMM connector can be mentioned. In particular, the connector for a memory module for a notebook computer has a latch structure for mounting and has a notch for alignment, so that the shape becomes very complicated.

In the case of such an asymmetric electronic component, the symmetry is different from a normal connector (symmetrical electronic component) having symmetry with respect to any of the XY axis plane, the YZ axis surface, and the XZ axis surface of the molded product. Therefore, there is a limit to the improvement of warpage deformation from the aspect of the molding method. Further, in the case of an asymmetric electronic component having a complicated shape, the orientation of the resin and the filler in the molded product becomes complicated, higher fluidity is required, and it is more difficult to suppress the warp deformation.

As a technique for solving such a problem, for example, in Patent Document 1, a specific fibrous filler and a specific plate-like filler are molded from a liquid crystal resin composition in which a specific amount is blended, and molded. Disclosed are asymmetric electronic components that are not symmetric with respect to any of the XY axis, YZ axis, and XZ axis of the article.

International Publication No. 2008/023839

However, the liquid crystal resin composition disclosed in Patent Document 1 is due to factors such as shape changes due to an increase in the integration rate in recent asymmetric electronic components, particularly a decrease in the distance between pitches, a decrease in product height, and an increase in the number of poles. It has been found that the conventional liquid crystal resin composition such as a product may not be able to cope with it. That is, the conventional liquid crystal resin composition does not have sufficient heat resistance and fluidity, and it is difficult to obtain an asymmetric electronic component in which warpage deformation is suppressed from such a liquid crystal resin composition.

In addition, the liquid crystal resin composition may have a problem of blister generation. That is, liquid crystal resins such as liquid crystal polyesters and liquid crystal polyester amides have good high temperature thermal stability, and are often used as materials that require heat treatment at high temperatures. However, if the molded product is left in high temperature air or liquid for a long time, there arises a problem that fine swelling called blister is generated on the surface.

One cause of this phenomenon is that the decomposition gas generated when the liquid crystal resin is in a molten state is brought into the molded product, and then the gas expands when heat treatment is performed at a high temperature, and the molded product is softened by heating. The surface is pushed up, and the pushed up part appears as a blister. The generation of blisters can also be reduced by sufficiently degassing from the vent holes during melt extrusion of the material and by preventing the blisters from staying in the molding machine for a long time during molding. However, the condition range is very narrow, and it is not sufficient to obtain a molded product in which the generation of blisters is suppressed, that is, a molded product having blister resistance. The fundamental solution of blister generation requires improvement of the quality of the liquid crystal resin itself, and known liquid crystal resins and methods using the same are insufficient to solve the problem of blister generation.

Another cause of blister generation is that the cavity (delamination) caused by the distortion that occurs at the boundary between the skin layer and the core layer and the non-uniform layer structure caused by the complicated molded product shape expands thermally during reflow and softens by heating. The surface of the molded product is pushed up, and the pushed up part appears as a blister. Especially in the production of molded products with a large difference in wall thickness, the melted liquid crystal resin composition is sufficiently filled in the thick part due to the flow phenomenon peculiar to the liquid crystal resin in the process of flowing from the thin part to the thick part. There is a problem that a non-uniform layer structure is likely to be formed without being formed. The conventional liquid crystal composition is insufficient to solve the problem of blister generation, especially in a molded product having such a large difference in wall thickness.

The present invention has been made to solve the above problems, and an object thereof is a liquid crystal resin composition for providing a molded product having excellent heat resistance and mechanical properties and suppressed warpage deformation and blister generation, and a liquid crystal resin composition. An object of the present invention is to provide an electronic component including a molded product of the liquid crystal resin composition.

The present inventors have conducted extensive research to solve the above problems. As a result, the liquid crystal resin, the fibrous wollastonite having a specific composition, and the plate-like filler are contained, and the liquid crystal resin is an aromatic polyesteramide, and the fibrous wollastonite, the plate-like filler, and the plate-like filler are contained. We have found that the above problems can be solved by using a liquid crystal resin composition in which the content of each of these totals is within a predetermined range, and have completed the present invention. More specifically, the present invention provides the following.

A liquid crystal resin composition containing (1) a liquid crystal resin, (B) fibrous wollastonite, and (C) a plate-like filler, wherein the (A) liquid crystal resin is aromatic. It is a polyester amide, and in the fibrous wollastonite, the content of Al ₂ O ₃ is 0.05 to 0.65% by mass, and the content of Fe ₂ O ₃ is 0.05 to 1.0% by mass. The content of the (B) fibrous wollastonite is 5 to 25% by mass, and the content of the (C) plate-like filler is 22.5 with respect to the entire liquid crystal resin composition. A liquid crystal resin composition having an amount of about 40% by mass, and the total content of the (B) fibrous wollastonite and the (C) plate-like filler is 35 to 47.5% by mass.

(2) The liquid crystal resin composition according to (1), wherein the (C) plate-like filler is talc.

(3) The liquid crystal resin composition according to (1) or (2) for electronic parts, wherein the electronic parts include a molded product of the liquid crystal resin composition, and the molded product is thick. A liquid crystal having an unbalanced wall structure in which the wall thickness difference between the wall portion and the thin wall portion is 0.5 mm or more, and the path from the gate portion of the molded product to the thick wall portion passes through the thin wall portion. Resin composition.

(4) The liquid crystal resin composition according to any one of (1) to (3), which is for an electronic component that undergoes a reflow step, and the reflow step involves heating in a preheat zone and heating in a reflow zone. Including, in the preheat zone, the set temperature is 140 to 170 ° C. and the processing time is 1 to 3 minutes, and in the reflow zone, the set temperature is 180 to 210 ° C. and the processing time is 30 to 120 seconds, and the actual measurement is performed. A liquid crystal resin composition having an average temperature of 183 ° C. or higher and an actually measured peak temperature of 220 to 270 ° C.

(5) An electronic component containing the molded product of the liquid crystal resin composition according to (1) or (2), having a product total length of 30 mm or more and a product height of 5 mm or more.

(6) The molded product has no symmetry with respect to any of the XY axis plane, the YZ axis surface, and the XZ axis surface, and the electronic component is an asymmetric electronic component according to (5). Electronic components.

(7) A connector for a memory module having a pitch distance of 0.6 mm or less, a product total length of 60.0 mm or more, a product height of 5 mm or more and 10.0 mm or less, and a number of poles of 200 poles or more (5) or (6). ) Described in the electronic component.

(8) The molded product has an uneven wall thickness structure in which the wall thickness difference between the thick portion and the thin wall portion is 0.5 mm or more, and the path from the gate portion of the molded product to the thick wall portion is the thin wall portion. The electronic component according to any one of (5) to (7), which has a shape passing through a portion.

(9) The electronic component according to any one of (5) to (8) that undergoes a reflow step, wherein the reflow step includes heating in the preheat zone and heating in the reflow zone, and is set in the preheat zone. The temperature is 140 to 170 ° C., the processing time is 1 to 3 minutes, the set temperature is 180 to 210 ° C., the processing time is 30 to 120 seconds, and the measured average temperature is 183 ° C. or higher in the reflow zone. Electronic components with an actually measured peak temperature of 220 to 270 ° C.

According to the present invention, there is provided a liquid crystal resin composition which is excellent in heat resistance and mechanical properties and which gives a molded product in which warpage deformation and blister generation are suppressed, and an electronic component including the molded product of the liquid crystal resin composition. can do.

It is a figure which shows the DDR-DIMM connector molded in the Example. In addition, A indicates a gate position. The unit of the numerical value in the figure is mm. It is a figure which shows the measurement point in the measurement of the warp of the DDR-DIMM connector performed in the Example. It is a figure which shows the molded product which was molded in the Example and used in the step sensitivity blister evaluation. In addition, A indicates a gate position. The unit of the numerical value in the figure is mm.

<Liquid crystal resin composition>
The liquid crystal resin composition according to the present invention is a liquid crystal resin composition containing (A) a liquid crystal resin, (B) fibrous wollastonite, and (C) a plate-like filler, and is the above-mentioned (A). ) The liquid crystal resin is an aromatic polyester amide, and in the fibrous wollastonite, the content of Al ₂ O ₃ is 0.05 to 0.65% by mass, and the content of Fe ₂ O ₃ is 0. The content of the (B) fibrous wollastonite is 5 to 25% by mass with respect to the entire liquid crystal resin composition of 0.05 to 1.0% by mass, and the content of the (C) plate-like filler is 5 to 25% by mass. The content of the above is 22.5 to 40% by mass, and the total content of the (B) fibrous wollastonite and the (C) plate-like filler is 35 to 47.5% by mass.

[(A) Liquid crystal resin]
The liquid crystal resin (A) used in the present invention refers to a melt-processable polymer having a property of forming an optically anisotropic molten phase. The properties of the anisotropic molten phase can be confirmed by a conventional polarization inspection method using an orthogonal polarizing element. More specifically, the confirmation of the anisotropic molten phase can be carried out by observing the molten sample placed on the Leitz hot stage at a magnification of 40 times under a nitrogen atmosphere using a Leitz polarizing microscope. The liquid crystal resin applicable to the present invention normally transmits polarized light even in a molten stationary state when inspected between orthogonal transducers, and exhibits optical anisotropy.

The liquid crystal resin (A) as described above is not particularly limited as long as it is an aromatic polyester amide. The aromatic polyester amide may be a total aromatic polyester amide or a polyester amide partially containing the aromatic polyester amide in the same molecular chain, and the total aromatic polyester amide is preferable from the viewpoint of heat resistance and the like. The liquid crystal resin (A) is preferably at least about 2.0 dl / g, more preferably 2.0 to 10.0 dl / g when dissolved in pentafluorophenol at 60 ° C. at a concentration of 0.1% by mass. Aromatic polyesteramides having a logarithmic viscosity (IV) of are also preferably used.

The generation of blisters is not determined only by the melt viscosity, and even if the liquid crystal resin compositions exhibit the same melt viscosity, it is possible that blisters are generated on one side and no blisters are generated on the other side. The same applies to the type or content of filler or polymer and compound conditions. In this way, blister generation is an index that is determined by the complex relationship of complex factors. Here, as demonstrated in Examples and Comparative Examples, if the liquid crystal resin (A) is an aromatic polyester amide, in the case of a molded product having a large difference in wall thickness, provided that the other requirements of the present invention are satisfied. Blister generation is suppressed. When molding a complicated molded product, for example, a mold is used in which a cavity branched in a direction perpendicular to the mainstream of the melt of the liquid crystal resin composition extends. (A) When the liquid crystal resin is an aromatic polyester amide, the melt easily spreads even in the cavity extending in the vertical direction and fills the voids easily, so that the blister in the molded product having a large wall thickness difference is easy to spread. It is easy to suppress the occurrence.

The aromatic polyester amide as the (A) liquid crystal resin applicable to the present invention is particularly preferably selected from the group consisting of a repeating unit derived from an aromatic hydroxycarboxylic acid and an aromatic hydroxyamine and an aromatic diamine. It is an aromatic polyester amide having a repeating unit derived from one compound and a constituent component thereof.

More specifically
(1) Repeating units derived mainly from (a) one or more of aromatic hydroxycarboxylic acids and their derivatives, and (b) one or two of aromatic hydroxyamines, aromatic diamines, and their derivatives. Polyesteramide consisting of repeating units derived from species or more and (c) aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and repeating units derived from one or more of their derivatives;
(2) Repeating units mainly derived from (a) one or more of aromatic hydroxycarboxylic acids and their derivatives, and (b) one or two of aromatic hydroxyamines, aromatic diamines, and their derivatives. Repeating units derived from species or higher, (c) aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and repeating units derived from one or more of their derivatives, and (d) aromatic diols, alicyclics. Examples thereof include polyesteramides composed of group diols, aliphatic diols, and repeating units derived from at least one or more of the derivatives thereof. Further, a molecular weight adjusting agent may be used in combination with the above-mentioned constituent components, if necessary.

（Ｘ：アルキレン（Ｃ_１～Ｃ_４）、アルキリデン、－Ｏ－、－ＳＯ－、－ＳＯ_２－、－Ｓ－、及び－ＣＯ－より選ばれる基である）

（Ｙ：－（ＣＨ_２）_ｎ－（ｎ＝１～４）及び－Ｏ（ＣＨ_２）_ｎＯ－（ｎ＝１～４）より選ばれる基である。）Preferred examples of the specific compound constituting the (A) liquid crystal resin applicable to the present invention are aromatic hydroxycarboxylic acids such as p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid; 2,6-dihydroxy. Aromatic diols such as naphthalene, 1,4-dihydroxynaphthalene, 4,4'-dihydroxybiphenyl, hydroquinone, resorcin, the compound represented by the following general formula (I), and the compound represented by the following general formula (II). Aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 4,4'-diphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and compounds represented by the following general formula (III); p-aminophenol, p- Aromatic amines such as phenylenediamine can be mentioned.

(X: A group selected from alkylene (C ₁ to C ₄ ), alkylidene, -O-, -SO-, -SO _2- , -S-, and -CO-)

(Y:-(CH ₂ ) _n- (n = 1 to 4) and -O (CH ₂ ) _n O- (n = 1 to 4).)

The liquid crystal resin (A) used in the present invention can be prepared by a known method using a direct polymerization method or an ester exchange method from the above-mentioned monomer compound (or a mixture of monomers), and is usually a melt polymerization method. , Solution polymerization method, slurry polymerization method, solid phase polymerization method, etc., or a combination of two or more thereof is used, and a melt polymerization method or a combination of a melt polymerization method and a solid phase polymerization method is preferably used. The above compounds having an ester-forming ability may be used as they are for polymerization, or may be modified from a precursor to a derivative having an ester-forming ability by using an acylating agent or the like in the pre-polymerization stage. good. Examples of the acylating agent include acetic anhydride and the like.

Various catalysts can be used for the polymerization. Typical catalysts that can be used are potassium acetate, magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, antimony trioxide, tris (2,4-pentandionato) cobalt (III). ) And other metal salt-based catalysts, and organic compound-based catalysts such as N-methylimidazole and 4-dimethylaminopyridine can be mentioned. The amount of the catalyst used is generally preferably about 0.001 to 1% by mass, particularly preferably about 0.01 to 0.2% by mass, based on the total weight of the monomer.

The melt viscosity of the liquid crystal resin (A) obtained by the above method is not particularly limited. Generally, those having a melt viscosity at a molding temperature of 1000 sec ^-1 and a shear rate of 10 Pa · s or more and 600 Pa · s or less can be used. However, the one having a very high viscosity by itself is not preferable because the fluidity is very deteriorated. The liquid crystal resin (A) may be a mixture of two or more kinds of liquid crystal resins.

(A) The melting point (hereinafter, also referred to as “Tm”) and the crystallization temperature (hereinafter, also referred to as “Tc”) of the liquid crystal resin are not particularly limited. Difference between Tm and Tc Tm-Tc is preferably 45 ° C. or lower, more preferably 42 ° C. or lower, still more preferably 40 ° C. or lower, in that blister generation is easily suppressed and mechanical strength is easily maintained. The lower limit of Tm-Tc is not particularly limited, and may be any of 0 ° C, 1 ° C, 5 ° C, 10 ° C, 20 ° C, 30 ° C, and 37 ° C.

In the liquid crystal resin composition of the present invention, the preferable content of the liquid crystal resin (A) is 52.5 to 65% by mass. When the content of the component (A) is within the above range, the composition tends to suppress the generation of blister while maintaining the fluidity. The content of the component (A) is more preferably 53.5 to 62.5% by mass, and even more preferably 55 to 60% by mass.

[(B) Fibrous Wollastonite]
The component (B) is fibrous wollastonite, and in the component (B), the content of Al ₂ O ₃ is 0.05 to 0.65% by mass, and the content of Fe ₂ O ₃ is 0.05. ~ 1.0% by mass. That is, the component (B) contains Al ₂ O ₃ and Fe ₂ O ₃ in an amount in the above range in addition to SiO ₂ and CaO, which are the main components thereof. By containing Al ₂ O ₃ and Fe ₂ O ₃ in the component (B), the composition has a low melt viscosity and is easy to maintain fluidity, but Al ₂ O ₃ and Fe in the component (B) are easy to maintain. If the content of each of ₂ O ₃ is too large, the problem of blister generation may occur. By containing Al ₂ O ₃ and Fe ₂ O ₃ in the amount in the above range as the component (B), the composition tends to suppress the generation of blister while maintaining the fluidity. In this specification, as the content of Al ₂ O ₃ and Fe ₂ O ₃ in the component (B), the values analyzed in accordance with JIS K 0119 are adopted.

In the component (B), the content of Al ₂ O ₃ is preferably 0.08 to 0.45% by mass, more preferably 0.11 to 0.30% by mass, and the content of Fe ₂ O ₃ is. It is preferably 0.1 to 0.5% by mass, more preferably 0.18 to 0.23% by mass. When the content of Al ₂ O ₃ and the content of Fe ₂ O ₃ are within the above ranges, the composition is more likely to suppress the generation of blister.

The average fiber length of the component (B) is preferably 50 to 200 μm, more preferably 70 to 180 μm, and even more preferably 90 to 160 μm. When the average fiber length is within the above range, the composition is more likely to suppress the generation of blister. As the average fiber length, a stereomicroscope image is taken from a CCD camera into a PC, and a value measured by an image processing method by an image measuring machine is adopted. The component (B) in the liquid crystal resin composition is obtained by heating the liquid crystal resin composition at 600 ° C. for 2 hours to incinerate it.

The preferred average fiber diameter of the component (B) is 1 to 20 μm or less, and the more preferable average fiber diameter is 5 to 16 μm. When the average fiber diameter is within the above range, the composition is more likely to suppress the generation of blister. As the average fiber diameter, a stereomicroscope image is taken from a CCD camera into a PC, and a value measured by an image processing method using an image measuring machine is adopted.

In the liquid crystal resin composition of the present invention, the content of the component (B) is 5 to 25% by mass. When the content of the component (B) is within the above range, the composition is excellent in fluidity while maintaining mechanical properties, so that the minimum filling pressure at the time of molding is unlikely to become excessive, and further, blister generation occurs. Easy to suppress. The content of the component (B) is more preferably 7.5 to 22.5% by mass, and even more preferably 10 to 20% by mass. The component (B) can be used alone or in combination of two or more.

[(C) Plate-shaped filler]
The component (C) is a plate-shaped filler. Since the liquid crystal resin composition according to the present invention contains the component (C), the minimum filling pressure at the time of molding is unlikely to be excessive, and it is easy to obtain a molded product in which warpage deformation is suppressed. The component (C) can be used alone or in combination of two or more.

In the liquid crystal resin composition of the present invention, the content of the component (C) is 22.5 to 40% by mass. When the content of the component (C) is within the above range, the minimum filling pressure at the time of molding is unlikely to be excessive in the composition, and it is easy to obtain a molded product in which warpage deformation is suppressed from the composition. .. The content of the component (C) is more preferably 23.5 to 37.5% by mass, and even more preferably 25 to 35% by mass.

Examples of the plate-like filler in the present invention include talc, mica, glass flakes, various metal foils and the like. One or more selected from talc and mica are preferable in that the warp deformation of the molded product obtained from the liquid crystal resin composition is suppressed without deteriorating the fluidity of the liquid crystal resin composition, and talc is more preferable. preferable. The average particle size of the plate-shaped filler is not particularly limited, and it is desirable that the average particle size is small in consideration of the fluidity in the thin-walled portion. On the other hand, in order to reduce the warp deformation of molded products such as electronic parts obtained from the liquid crystal resin composition, it is necessary to maintain a certain size. Specifically, 1 to 100 μm is preferable, and 5 to 50 μm is more preferable.

〔talc〕
As the talc that can be used in the present invention, the total content of Fe ₂ O ₃ , Al ₂ O ₃ and Ca O is 2.5% by mass or less with respect to the total solid content of the talc, and Fe ₂ O ₃ and Al are used. It is preferable that the _total content of _2O3 is more than 1.0% by mass and 2.0% by mass or less, and the content of CaO is less than 0.5% by mass. That is, the talc that can be used in the present invention contains at least one of Fe ₂ O ₃ , Al ₂ O ₃ , and CaO in addition to SiO ₂ and MgO, which are the main components thereof, and each component has the above-mentioned content range. It may be contained in. In this specification, as the content of Fe ₂ O ₃ , Al ₂ O ₃ , and CaO in talc, the values analyzed in accordance with JIS M 8851 are adopted.

When the total content of Fe ₂ O ₃ , Al ₂ O ₃ and CaO in the above talc was 2.5% by mass or less, the liquid crystal resin composition was molded from the molding processability and the liquid crystal resin composition. The heat resistance of molded products such as electronic parts does not deteriorate easily. Therefore, the total content of Fe ₂ O ₃ , Al ₂ O ₃ and CaO is preferably 1.0% by mass or more and 2.0% by mass or less.

Further, among the above talcs, talc having a total content of Fe ₂ O ₃ and Al ₂ O ₃ of more than 1.0% by mass is easily available. Further, in the above talc, when the total content of Fe ₂ O ₃ and Al ₂ O ₃ is 2.0% by mass or less, the liquid crystal resin composition is molded from the molding processability and the liquid crystal resin composition. The heat resistance of molded products such as electronic parts does not deteriorate easily. Therefore, the total content of Fe ₂ O ₃ and Al ₂ O ₃ is preferably more than 1.0% by mass and 1.7% by mass or less.

Further, in the above talc, when the CaO content is less than 0.5% by mass, the molding processability of the liquid crystal resin composition and the heat resistance of the molded product such as an electronic component molded from the liquid crystal resin composition Is hard to get worse. Therefore, the CaO content is preferably 0.01% by mass or more and 0.4% by mass or less.

The mass-based or volume-based cumulative average particle diameter ( _D50 ) of talc in the present invention measured by a laser diffraction method is determined from the viewpoint of preventing warpage deformation of the molded product and maintaining the fluidity of the liquid crystal resin composition. It is preferably 4.0 to 20.0 μm, more preferably 10 to 18 μm.

[Mica]
Mica is a pulverized silicate mineral containing aluminum, potassium, magnesium, sodium, iron and the like. Examples of mica that can be used in the present invention include muscovite, phlogopite, biotite, artificial mica, and the like. Of these, muscovite is preferable because it has a good hue and is inexpensive.

Further, in the production of mica, a wet pulverization method and a dry pulverization method are known as methods for pulverizing minerals. The wet pulverization method is a method in which rough mica is roughly pulverized by a dry pulverizer, water is added, and the main pulverization is performed by wet pulverization in a slurry state, followed by dehydration and drying. Although the dry pulverization method is a low-cost and general method as compared with the wet pulverization method, it is easier to pulverize the mineral thinly and finely by using the wet pulverization method. In the present invention, it is preferable to use a thin and fine pulverized product because a mica having a preferable average particle size and thickness described later can be obtained. Therefore, in the present invention, it is preferable to use mica produced by the wet pulverization method.

Further, since the wet pulverization method requires a step of dispersing the object to be crushed in water, a coagulation settling agent and / or a settling aid is added to the object to be pulverized in order to improve the dispersion efficiency of the object to be pulverized. Is common. Examples of the coagulation sedimenting agent and the sedimentation aid that can be used in the present invention include polyaluminum chloride, aluminum sulfate, ferrous sulfate, ferric sulfate, copper chloride, polyiron sulfate, ferric chloride, and iron-silica inorganic high. Examples thereof include ferric chloride-silica inorganic polymer flocculants, slaked lime (Ca (OH) ₂ ), caustic soda (NaOH), soda ash (Na ₂ CO ₃ ) and the like. These agglomerates and sedimentation aids have an alkaline or acidic pH. The mica used in the present invention preferably does not use a coagulation settling agent and / or a settling aid during wet pulverization. When mica that has not been treated with a coagulation sedimentation agent and / or a sedimentation aid is used, decomposition of the polymer in the liquid crystal resin composition is unlikely to occur, and a large amount of gas is less likely to be generated or the molecular weight of the polymer is less likely to decrease. It is easy to maintain better performance of molded products such as.

The mica that can be used in the present invention preferably has an average particle size of 10 to 100 μm measured by a microtrack laser diffraction method, and particularly preferably an average particle size of 20 to 80 μm. When the average particle size of the mica is 10 μm or more, the effect of improving the rigidity of the molded product is likely to be sufficient, which is preferable. When the average particle size of the mica is 100 μm or less, the rigidity of the molded product is likely to be sufficiently improved and the weld strength is likely to be sufficient, which is preferable. Further, when the average particle size of the mica is 100 μm or less, it is easy to secure sufficient fluidity for molding the electronic component or the like of the present invention.

The thickness of the mica that can be used in the present invention is preferably 0.01 to 1 μm, particularly preferably 0.03 to 0.3 μm, as measured by observation with an electron microscope. When the thickness of the mica is 0.01 μm or more, the mica is less likely to crack during the melt processing of the liquid crystal resin composition, and the rigidity of the molded product may be easily improved, which is preferable. When the thickness of the mica is 1 μm or less, the effect of improving the rigidity of the molded product is likely to be sufficient, which is preferable.

The mica that can be used in the present invention may be surface-treated with a silane coupling agent or the like, and / or may be granulated with a binder to form granules.

Further, the total content of the component (B) and the component (C) is 35 to 47.5% by mass, preferably 37.5 to 46.5% by mass in the liquid crystal resin composition of the present invention. It is more preferably 40 to 45% by mass. When the total content is 35% by mass or more, it is easy to obtain a molded product in which warpage deformation is suppressed. When the total content is 47.5% by mass or less, the composition is excellent in fluidity while maintaining mechanical properties, so that the minimum filling pressure at the time of molding is unlikely to become excessive, and further, blister generation occurs. Is easy to suppress.

[Other ingredients]
The liquid crystal resin composition according to the present invention includes other polymers, other fillers, and known substances generally added to synthetic resins, that is, antioxidants and ultraviolet rays, as long as the effects of the present invention are not impaired. Stabilizers such as absorbents, antistatic agents, flame retardants, colorants such as dyes and pigments, lubricants, mold release agents, crystallization accelerators, crystal nucleating agents and other other components are also added as appropriate according to the required performance. be able to. Other components may be used alone or in combination of two or more. The other fillers refer to fillers other than (B) fibrous wollastonite and (C) plate-like fillers, and examples thereof include granular fillers such as silica.

[Method for preparing liquid crystal resin composition]
The method for preparing the liquid crystal resin composition of the present invention is not particularly limited. For example, the liquid crystal resin composition can be obtained by blending the above components (A) to (C) and optionally other components and melt-kneading them using a single-screw or twin-screw extruder. Preparation is done.

Since the liquid crystal resin composition according to the present invention has excellent fluidity, the minimum filling pressure at the time of molding is unlikely to be excessive, and a complicated shape such as an electronic component, particularly an asymmetric electronic component having a latch structure or a notch, etc. It is possible to preferably mold a part or the like having the above. The degree of fluidity is determined by the minimum filling pressure of the connector. That is, the minimum injection filling pressure at which a good molded product can be obtained when the DDR-DIMM connector shown in FIG. 1 is injection molded is specified as the minimum filling pressure. The lower the minimum filling pressure, the better the fluidity is evaluated.

The melt viscosity of the liquid crystal resin composition measured in accordance with ISO11443 at a temperature 10 to 30 ° C. higher than the melting point of the liquid crystal resin and a shear rate of 1000 / sec is preferably ¹ × 105 Pa · s or less. It is preferably 5 Pa · s or more and 1 × 10 ² Pa · s or less. When the melt viscosity is ¹ × 105 Pa · s or less, the part having a complicated shape such as a latch structure or a notch in an asymmetric electronic part is particularly formed during molding of a part having a complicated shape in an electronic part. At the time of molding, it is easy to secure the fluidity of the liquid crystal resin composition, and the filling pressure is unlikely to become excessive.

The liquid crystal resin composition of the present invention is preferably for electronic parts, the electronic parts include a molded product of the liquid crystal resin composition, and the molded product has a wall thickness of a thick portion and a thin portion. It has an uneven thickness structure with a difference of 0.5 mm or more, and has a shape in which the path from the gate portion of the molded product to the thick wall portion passes through the thin wall portion. Since the molded product has the above-mentioned shape, it is necessary that the melted liquid crystal resin composition flows from the thin portion to the thick portion at the time of production thereof. The liquid crystal resin composition of the present invention not only has an uneven thickness structure in which the wall thickness difference between the thick portion and the thin portion is 0.5 mm or more, but also has a liquid crystal resin from the thin portion to the thick portion. The generation of blister can be effectively suppressed in electronic parts including molded products that require the flow of the composition. A typical example of such an electronic component is a connector for a memory module such as a DDR connector; an interface connector such as a SATA connector. Examples of DDR connectors are as described below.

Further, the liquid crystal resin composition of the present invention is preferably for an electronic component that undergoes a reflow step, and the reflow step includes heating in the preheat zone and heating in the reflow zone, and the set temperature in the preheat zone is set. The temperature is 140 to 170 ° C. and the treatment time is 1 to 3 minutes. In the reflow zone, the set temperature is 180 to 210 ° C., the treatment time is 30 to 120 seconds, and the average temperature actually measured is 183 ° C. or higher. The peak temperature is 220 to 270 ° C. In the preheat zone, by maintaining the temperature at 140 to 170 ° C. for 1 to 3 minutes, the solder paste is heated, and the surface to which the flux in the paste is soldered can be appropriately washed. After heating in the preheat zone, the transition to heating in the reflow zone can be made, for example, by raising the oven temperature at 1 to 3 ° C. per second. In the reflow zone, the set temperature is 180 to 210 ° C. and the processing time is 30 to 120 seconds, so that the actual temperature of the electronic component is at least 60 seconds or more and 183 ° C. (melting point of solder) or more, resulting in soldering. In addition to being able to effectively prevent distortion due to soldering, bridging, connection in low temperature conditions, etc., the processing time at the measured peak temperature of 220 to 260 ° C. is maintained for 30 to 120 seconds, so sufficient reflow is completed. be able to. The liquid crystal resin composition of the present invention can effectively suppress the generation of blisters in electronic components that have undergone the above reflow process.

<Electronic components>
By molding the liquid crystal resin composition according to the present invention, the electronic component of the present invention can be obtained. The electronic component of the present invention is not particularly limited, and examples thereof include an electronic component having a total length of 30 mm or more and a product height of 5 mm or more, including a molded product of the liquid crystal resin composition according to the present invention. Among the electronic components of the present invention, the asymmetric electronic component refers to an electronic component including the molded product having no symmetry with respect to any of the XY axial plane, the YZ axial plane, and the XZ axial plane.

In the case of ordinary connectors (electronic components) that are often found on the market, they have symmetry on any of the XY axis planes, the YZ axis planes, and the XZ axis planes, so that the symmetry should be maintained during molding. It is possible to control the dimensional accuracy and warpage of the product by setting the gate position and design. On the other hand, the asymmetric electronic component has a complicated shape, and it is difficult to suppress the warp deformation by the molding method. In the electronic component of the present invention, particularly the asymmetric electronic component, the warp deformation is suppressed by using the liquid crystal resin composition of the present invention.

Typical examples of such electronic components include connectors and sockets.
Examples of the connector include a memory module connector and an interface connector. Examples of the memory module connector include a DIMM connector; a DDR-DIMM connector, a DDR2-DIMM connector, a DDR-SO-DIMM connector, a DDR2-SO-DIMM connector, a DDR-Micro-DIMM connector, a DDR2-Micro-DIMM connector, and the like. DDR connector and the like. Examples of the interface connector include a SATA connector, a SAS connector, an NGFF connector and the like. Among them, the DDR connector, SATA connector, SAS connector, and NGFF connector are suitable, and in particular, they are thin-walled and complicatedly shaped memory module connectors for notebook computers, with a pitch-to-pitch distance of 0.6 mm or less and a total product length. Those having a product height of 60.0 mm or more, a product height of 5 mm or more and 10.0 mm or less, and a number of poles of 200 or more are particularly suitable. Such a connector for a memory module is used in an IR reflow process for surface mounting at a peak temperature of 230 to 280 ° C., and the warp before the IR reflow process is 0.1 mm or less, and the warp before and after the reflow. The difference between the two is required to be 0.05 mm or less, and according to the present invention, such a requirement can be satisfied.

Examples of the socket include a memory card socket such as a card bus, a CF card, a memory stick, a PC card, an SD card, an SDMo, a smart card, and a smart media card.

The molding method for obtaining the electronic component of the present invention is not particularly limited, and it is preferable to select molding conditions without residual internal stress in order to obtain the electronic component in which warpage deformation is suppressed. In order to lower the filling pressure and reduce the residual internal stress of the electronic component, the cylinder temperature of the molding machine is preferably a temperature equal to or higher than the melting point of the liquid crystal polymer.

The mold temperature is preferably 70 to 100 ° C. If the mold temperature is low, the liquid crystal resin composition filled in the mold may cause poor flow, which is not preferable. If the mold temperature is high, problems such as burrs may occur, which is not preferable. The injection speed is preferably 150 mm / sec or more. If the injection rate is low, only unfilled molded products may be obtained, and even if a fully filled molded product is obtained, the filling pressure is high and the residual internal stress is large, resulting in a molded product with large warpage deformation. Only parts may be available.

The electronic component of the present invention is suppressed from warpage deformation. The degree of warpage of electronic components is determined as follows. That is, with the DDR-DIMM connector shown in FIG. 1, the height is measured at a plurality of positions indicated by black circles in FIG. 2, and the difference between the maximum height and the minimum height from the least squares plane is taken as a sled. In the electronic component of the present invention, the change in warpage is suppressed before and after performing IR reflow.

Further, the electronic component of the present invention suppresses the generation of blister. The degree of blister generation is determined by the blister temperature. That is, the presence or absence of blister generation on the surface of the molded product sandwiched between hot presses at a predetermined temperature for 5 minutes is visually observed, and the maximum temperature at which the number of blister generation becomes zero is defined as the blister temperature. It is evaluated that the higher the blister temperature, the more the blister generation is suppressed.

Further, the electronic component of the present invention is excellent in heat resistance, for example, heat resistance as evaluated by high temperature rigidity. High temperature stiffness is evaluated by measuring the deflection temperature under load in accordance with ISO75-1 and ISO75-1.

In one embodiment of the electronic component according to the present invention, the molded product has an uneven thickness structure in which the wall thickness difference between the thick portion and the thin wall portion is 0.5 mm or more, and the molded product is described from the gate portion of the molded product. The path leading to the thick portion has a shape that passes through the thin portion. According to the present invention, the generation of blisters can be effectively suppressed in such electronic components.

In another embodiment of the electronic component according to the present invention, the electronic component undergoes a reflow process.
The reflow step includes heating in the preheat zone and heating in the reflow zone.
In the preheat zone, the set temperature is 140 to 170 ° C. and the processing time is 1 to 3 minutes.
In the reflow zone, the set temperature is 180 to 210 ° C., the processing time is 30 to 120 seconds, the measured average temperature is 183 ° C. or higher, and the measured peak temperature is 220 to 270 ° C. According to the present invention, the generation of blisters can be effectively suppressed in such an electronic component that undergoes the reflow process.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.

(A) Liquid crystal resin (manufacturing method of liquid crystal resin 1)
The following raw material monomers, metal catalysts, and acylating agents were charged into a polymerization vessel equipped with a stirrer, a reflux column, a monomer inlet, a nitrogen inlet, and a depressurization / outflow line, and nitrogen substitution was started.
(I) 4-Hydroxybenzoic acid: 1380 g (60 mol%) (HBA)
(II) 6-Hydroxy-2-naphthoic acid: 157 g (5 mol%) (HNA)
(III) Terephthalic acid: 484 g (17.5 mol%) (TA)
(IV) 4,4'-dihydroxybiphenyl: 388 g (12.5 mol%) (BP)
(V) 4-Acetoxyaminophenol: 17.2 g (5 mol%) (APAP)
Potassium acetate catalyst: 110 mg
Acetic anhydride: 1659 g

After charging the raw materials into the polymerization vessel, the temperature of the reaction system was raised to 140 ° C., and the reaction was carried out at 140 ° C. for 1 hour. Then, the temperature is further raised to 340 ° C. over 4.5 hours, and then the pressure is reduced to 10 Torr (that is, 1330 Pa) over 15 minutes while distilling acetic acid, excess acetic anhydride, and other low boiling points. Melt polymerization was performed. After the stirring torque reached a predetermined value, nitrogen was introduced to bring the polymer into a pressurized state from a reduced pressure state through a normal pressure state, the polymer was discharged from the lower part of the polymerization vessel, and the strands were pelletized and pelletized. The melting point of the obtained pellet was 336 ° C., the difference Tm-Tc between the melting point and the crystallization temperature was 40 ° C., and the melt viscosity was 20 Pa · s.

(Manufacturing method of liquid crystal resin 2)
The following raw material monomers, fatty acid metal salt catalysts, and acylating agents were charged into a polymerization vessel equipped with a stirrer, a reflux column, a monomer inlet, a nitrogen inlet, and a depressurization / outflow line, and nitrogen substitution was started.
(I) 4-Hydroxybenzoic acid 1385 g (60 mol%) (HBA)
(II) 6-Hydroxy-2-naphthoic acid 88 g (2.8 mol%) (HNA)
(III) 504 g (18.15 mol%) of terephthalic acid (TA)
(IV) Isophthalic acid 19 g (0.7 mol%) (IA)
(V) 4,4'-Dihydroxybiphenyl 415 g (13.35 mol%) (BP)
(VI) N-Acetyl-p-Aminophenol 126 g (5 mol%) (APAP)
Potassium acetate catalyst 120 mg
Acetic anhydride 1662g
After charging the raw materials, the temperature of the reaction system was raised to 140 ° C., and the reaction was carried out at 140 ° C. for 1 hour. Then, the temperature is further raised to 360 ° C. over 5.5 hours, and then the pressure is reduced to 10 Torr (that is, 1330 Pa) over 20 minutes to melt acetic acid, excess acetic anhydride, and other low boiling points. Polymerization was performed. After the stirring torque reached a predetermined value, nitrogen was introduced to bring the polymer into a pressurized state from a reduced pressure state through a normal pressure state, the polymer was discharged from the lower part of the polymerization vessel, and the strands were pelletized and pelletized. The obtained pellets had a melting point of 345 ° C., a Tm-Tc of 37 ° C., and a melt viscosity of 10 Pa · s.

(Manufacturing method of liquid crystal resin 3)
The following raw material monomers, metal catalysts, and acylating agents were charged into a polymerization vessel equipped with a stirrer, a reflux column, a monomer inlet, a nitrogen inlet, and a depressurization / outflow line, and nitrogen substitution was started.
(I) 4-Hydroxybenzoic acid: 1040 g (48 mol%) (HBA)
(II) 6-Hydroxy-2-naphthoic acid: 89 g (3 mol%) (HNA)
(III) Terephthalic acid: 547 g (21 mol%) (TA)
(IV) Isophthalic acid: 91 g (3.5 mol%) (IA)
(V) 4,4'-Dihydroxybiphenyl: 716 g (24.5 mol%) (BP)
Potassium acetate catalyst: 110 mg
Acetic anhydride: 1644 g

After charging the raw materials into the polymerization vessel, the temperature of the reaction system was raised to 140 ° C., and the reaction was carried out at 140 ° C. for 1 hour. Then, the temperature is further raised to 360 ° C. over 5.5 hours, and then the pressure is reduced to 5 Torr (that is, 667 Pa) over 20 minutes while distilling acetic acid, excess acetic anhydride, and other low boiling points. Melt polymerization was performed. After the stirring torque reached a predetermined value, nitrogen was introduced to bring the polymer into a pressurized state from a reduced pressure state through a normal pressure state, the polymer was discharged from the lower part of the polymerization vessel, and the strands were pelletized and pelletized. The obtained pellets had a melting point of 355 ° C, a Tm-Tc of 48 ° C, and a melt viscosity of 10 Pa · s.
The melt viscosities of the liquid crystal resins 1 to 3 were measured in the same manner as the method for measuring the melt viscosities of the liquid crystal resin compositions described later.

(filler)
(B) Fibrous wollastonite Fibrous wollastonite 1: SH-1250BJ manufactured by Kinsei Matek Co., Ltd.
Fibrous Wollastonite 2: NYGLOS 8 manufactured by NYCO Materials
Fibrous Wollastonite 3: FPW # 150 manufactured by Kinsei Matek Co., Ltd.
Fibrous Wollastonite 4: SH-800 manufactured by Kinsei Matek Co., Ltd.
The composition, average fiber length, and average fiber diameter of the fibrous wollastonites 1 to 4 are as shown in Table 1. The contents of SiO ₂ , CaO, Al ₂ O ₃ , and Fe ₂ O ₃ in the fibrous wollastonite are about 3 g of the fibrous wollastonite and cellulose powder (manufactured by GE Healthcare Bioscience Co., Ltd.). About 3 g of Whatman CC31) was mixed and pressed, and the tablet-shaped sample was obtained in accordance with JIS K 0119 using a fully automatic X-ray fluorescence analyzer (MagiX Pro Pw2540/00, manufactured by Spectris Co., Ltd.). Then, quantitative analysis was performed by the fundamental parameter (FP) method, and the calculation was performed.

(C) Plate-shaped filler talc: Crown talc PP manufactured by Matsumura Sangyo Co., Ltd., average particle size 12.8 μm

[Manufacturing of liquid crystal resin composition]
The above components are melt-kneaded at the following cylinder temperature using a twin-screw extruder (TEX30α type manufactured by Japan Steel Works, Ltd.) at the ratio (unit: mass%) shown in Table 2 or Table 3, and a liquid crystal resin. Composition pellets were obtained. At that time, the liquid crystal resin was supplied from the main feed port of the extruder, and the filler was supplied from the side feed port provided behind the main feed port in the extrusion direction.
Cylinder temperature:
350 ° C. (Examples 1 to 4, 8 and 9, Comparative Examples 1 to 5)
360 ° C (Examples 5 to 7)
370 ° C (Comparative Example 6)

[Measurement of melting point]
After observing the heat absorption peak temperature (Tm1) observed when the liquid crystal resin was measured at a temperature rise condition of 20 ° C./min from room temperature with a DSC manufactured by TA Instruments, 2 at a temperature of (Tm1 + 40) ° C. After holding for 1 minute, the temperature was once cooled to room temperature under the condition of lowering temperature of 20 ° C./min, and then the temperature of the heat absorption peak observed when the measurement was performed again under the condition of increasing temperature of 20 ° C./min was measured.

[Measurement of crystallization temperature]
After observing the heat absorption peak temperature (Tm1) observed when the liquid crystal resin was measured at a temperature rise condition of 20 ° C./min from room temperature with a DSC manufactured by TA Instruments, 2 at a temperature of (Tm1 + 40) ° C. After holding for a minute, the exothermic peak temperature observed when the temperature was measured under the cooling condition of 20 ° C./min was measured.

[Measurement of melt viscosity of liquid crystal resin composition]
Using Capillograph 1B type manufactured by Toyo Seiki Seisakusho Co., Ltd., using an orifice with an inner diameter of 1 mm and a length of 20 mm at a temperature 10 to 30 ° C higher than the melting point of the liquid crystal resin, to ISO11443 at a shear rate of 1000 / sec. According to this, the melt viscosity of the liquid crystal resin composition was measured and evaluated according to the following criteria. The measurement temperature was 360 ° C. for the liquid crystal resin composition using the liquid crystal resin 1, 350 ° C. for the liquid crystal resin composition using the liquid crystal resin 2, and the liquid crystal resin using the liquid crystal resin 3. The temperature of the composition was 380 ° C. The results are shown in Tables 2 and 3.
◯ (good): The melt viscosity was 35 Pa · s or less.
X (defective): The melt viscosity was more than 35 Pa · s.

[Bending test]
Under the following molding condition 1, the liquid crystal resin composition was injection-molded to obtain a molded product having a thickness of 0.8 mm, and the bending strength, breaking strain, and flexural modulus were measured according to ASTM D790, and according to the following criteria. evaluated. The results are shown in Tables 2 and 3.
Bending strength ◯ (good): The bending strength was 140 MPa or more.
X (defective): The bending strength was less than 140 MPa.
-Bending elastic modulus ◯ (good): The bending elastic modulus was 10,000 MPa or more.
X (defective): The flexural modulus was less than 10,000 MPa.
-Breaking strain ○ (good): The breaking strain was 2.4% or more.
X (defective): The breaking strain was less than 2.4%.

[Deflection temperature under load]
Under the following molding condition 1, the liquid crystal resin composition was injection-molded to obtain a molded product, and the deflection temperature under load was measured according to ISO75-1 and 2, and evaluated according to the following criteria. As the bending stress, 1.8 MPa was used. The results are shown in Tables 2 and 3.
◯ (good): The deflection temperature under the load was 240 ° C. or higher.
X (defective): The deflection temperature under load was less than 240 ° C.

[DDR connector sled]
The liquid crystal resin composition was injection-molded under the following molding condition 1 (gate: tunnel gate, gate size: φ0.75 mm), and the overall size was 70.0 mm × 26.0 mm × 4. A DDR-DIMM connector having 0 mmt, a distance between pitches of 0.6 mm, and a pin hole number of 100 × 2 was obtained.

The obtained connector was placed on a horizontal desk, and the height of the connector was measured by a Mitutoyo Quick Vision 404PROCNC image measuring machine. At that time, the heights were measured at a plurality of positions indicated by black circles in FIG. 2, and the difference between the maximum height and the minimum height from the least squares plane was defined as the warp of the DDR connector. The warp was measured before and after IR reflow performed under the following conditions, and evaluated according to the following criteria. The results are shown in Tables 2 and 3.
-Before reflow ○ (Good): The warp was 0.06 mm or less.
X (defective): The warp was more than 0.06 mm.
-After reflow ○ (good): The warp was 0.1 mm or less.
X (defective): The warp was more than 0.1 mm.
(IR reflow condition)
Measuring machine: Large tabletop reflow soldering device RF-300 (using far-infrared heater) manufactured by Japan Pulse Technology Laboratory
Sample feed rate: 140 mm / sec
Reflow oven transit time: 5 minutes Preheat zone temperature condition: 150 ° C
Reflow zone temperature condition: 190 ° C
Peak temperature: 251 ° C

[DDR connector deformation amount]
The difference in warpage before and after reflow measured by the above method was determined as the amount of deformation of the DDR connector and evaluated according to the following criteria. The results are shown in Tables 2 and 3.
◯ (good): The amount of deformation was 0.04 mm or less.
X (defective): The amount of deformation was more than 0.04 mm.

[DDR connector minimum filling pressure]
When the DDR-DIMM connector of FIG. 1 was injection molded, the minimum injection filling pressure at which a good molded product could be obtained was measured as the minimum filling pressure and evaluated according to the following criteria. The results are shown in Tables 2 and 3.
◯ (good): The minimum filling pressure was 130 MPa or less.
X (defective): The minimum filling pressure was more than 130 MPa.

[Blister temperature]
Under the following molding condition 1, the liquid crystal resin composition is injection-molded to obtain a molded product having a size of 12.5 mm × 120 mm × 0.8 mm, 30 of these molded products are immersed in silicone oil at a predetermined temperature, and washed with a detergent. After that, it was naturally dried, and it was visually examined whether or not blister was generated on the surface. The blister temperature was set to the maximum temperature at which the number of blister generations was zero among the 30 molded products, and was evaluated according to the following criteria. The results are shown in Tables 2 and 3.
◯ (good): The blister temperature was 300 ° C. or higher.
× (defective): The blister temperature was less than 300 ° C.

[Step sensitivity blister evaluation]
Using a molding machine (“TR100EH” manufactured by Sodick Co., Ltd.), the liquid crystal resin composition is injection-molded under the following molding condition 2, and the step is 0.5 mm / 0.4 mm or step 0 as shown in FIG. A 12.9 mm × 73 mm × 0.8 mm molded product having .2 mm / 0.3 mm was obtained.

The obtained molded product was subjected to IR reflow under the following conditions, and the presence or absence of blister generation was visually observed. Although the above-mentioned molded product has different steps at the gate, each step is regarded as an independent sample in this evaluation. Ten samples were evaluated for each of a total of 16 conditions of 4 steps and 4 injection speed conditions, and the number of samples in which blister was generated was counted among a total of 160 samples. The results are shown in Tables 2 and 3.
◯ (good): The number of blister generations was 20 or less.
X (defective): The number of blister generations was more than 20.
(IR reflow condition)
Measuring machine: Large tabletop reflow soldering device RF-300 (using far-infrared heater) manufactured by Japan Pulse Technology Laboratory
Sample feed rate: 140 mm / sec
Reflow oven transit time: 5 minutes Preheat zone set temperature: 150 ° C (processing time: 60 seconds)
Measured average temperature: 150 ° C
Set temperature of reflow zone: 190 ° C (processing time: 60 seconds)
Measured average temperature: 230 ° C or higher Actual peak temperature: 251 ° C

[Molding condition]
(Molding condition 1)
Molding machine:
SE100DU manufactured by Sumitomo Heavy Industries, Ltd. (for bending test, deflection temperature under load, and blister temperature)
SE30DUZ manufactured by Sumitomo Heavy Industries, Ltd. (in the case of DDR connector sled)
Cylinder temperature:
350 ° C. (Examples 1 to 4, 8 and 9, Comparative Examples 1 to 5)
360 ° C (Examples 5 to 7)
370 ° C (Comparative Example 6)
Mold temperature: 90 ° C
Injection speed: 33 mm / sec

(Molding condition 2)
Cylinder temperature:
350 ° C. (Examples 1 to 4, 8 and 9, Comparative Examples 1 to 5)
360 ° C (Examples 5 to 7)
370 ° C (Comparative Example 6)
Mold temperature: 80 ° C
Injection speed: 100, 200, 300, or 400 mm / sec

As can be seen from Tables 2 and 3, the molded product of the liquid crystal resin composition according to the present invention is excellent in heat resistance and mechanical properties, and warp deformation and blister generation are suppressed.

Claims (10)

(A) Liquid crystal resin,
A liquid crystal resin composition containing (B) fibrous wollastonite and (C) plate-like filler and used for electronic components .
The liquid crystal resin (A) is an aromatic polyester amide, and the liquid crystal resin is an aromatic polyester amide.
In the fibrous wollastonite, the content of Al ₂ O ₃ is 0.05 to 0.65% by mass, and the content of Fe ₂ O ₃ is 0.05 to 1.0% by mass.
For the entire liquid crystal resin composition,
The content of the liquid crystal resin (A) is 52.5 to 65% by mass.
The content of the fibrous wollastonite (B) is 5 to 25% by mass.
The content of the plate-shaped filler (C) is 22.5 to 40% by mass,
The total content of the (B) fibrous wollastonite and the (C) plate-like filler is 35 to 47.5% by mass.
And
The electronic component includes a molded product of the liquid crystal resin composition.
The molded product has an uneven wall thickness structure in which the wall thickness difference between the thick portion and the thin wall portion is 0.5 mm or more, and the path from the gate portion of the molded product to the thick wall portion passes through the thin wall portion. A liquid crystal resin composition having a shape to be molded. (A) Liquid crystal resin,
(B) Fibrous wollastonite and
(C) Plate-shaped filler
A liquid crystal resin composition for electronic components that contains a reflow process and undergoes a reflow process.
The liquid crystal resin (A) is an aromatic polyester amide, and the liquid crystal resin is an aromatic polyester amide.
In the fibrous wollastonite, Al ₂ O ₃ Content is 0.05 to 0.65% by mass, Fe ₂ O ₃ The content of is 0.05 to 1.0% by mass.
For the entire liquid crystal resin composition,
The content of the liquid crystal resin (A) is 52.5 to 65% by mass.
The content of the fibrous wollastonite (B) is 5 to 25% by mass.
The content of the plate-shaped filler (C) is 22.5 to 40% by mass,
The total content of the (B) fibrous wollastonite and the (C) plate-like filler is 35 to 47.5% by mass.
Is a liquid crystal resin composition. The reflow step includes heating in the preheat zone and heating in the reflow zone.
In the preheat zone, the set temperature is 140 to 170 ° C. and the processing time is 1 to 3 minutes.
The second aspect of the present invention, wherein in the reflow zone, the set temperature is 180 to 210 ° C., the processing time is 30 to 120 seconds, the measured average temperature is 183 ° C. or higher, and the measured peak temperature is 220 to 270 ° C. Liquid crystal resin composition. (A) Liquid crystal resin,
(B) Fibrous wollastonite and
(C) Plate-shaped filler
A liquid crystal resin composition containing neither a polycarbonate resin nor an epoxy group-containing copolymer.
The liquid crystal resin (A) is an aromatic polyester amide, and the liquid crystal resin is an aromatic polyester amide.
In the fibrous wollastonite, Al ₂ O ₃ Content is 0.05 to 0.65% by mass, Fe ₂ O ₃ The content of is 0.05 to 1.0% by mass.
For the entire liquid crystal resin composition,
The content of the liquid crystal resin (A) is 52.5 to 65% by mass.
The content of the fibrous wollastonite (B) is 5 to 25% by mass.
The content of the plate-shaped filler (C) is 22.5 to 40% by mass,
The total content of the (B) fibrous wollastonite and the (C) plate-like filler is 35 to 47.5% by mass.
Is a liquid crystal resin composition. The liquid crystal resin composition according to any one of claims 1 to 4, wherein the plate-shaped filler (C) is talc. An electronic component comprising the molded product of the liquid crystal resin composition according to any one of claims 1 to 5 , having a product total length of 30 mm or more and a product height of 5 mm or more. The electronic component according to claim 6, wherein the molded product has no symmetry with respect to any of the XY axis surface, the YZ axis surface, and the XZ axis surface, and the electronic component is an asymmetric electronic component. The electronic according to claim 6 or 7, which is a connector for a memory module having a pitch-to-pitch distance of 0.6 mm or less, a product total length of 60.0 mm or more, a product height of 5 mm or more and 10.0 mm or less, and a number of poles of 200 poles or more. parts. The molded product has an uneven wall thickness structure in which the wall thickness difference between the thick portion and the thin wall portion is 0.5 mm or more, and the path from the gate portion of the molded product to the thick wall portion passes through the thin wall portion. The electronic component according to any one of claims 6 to 8, which has a shape to be formed. The electronic component according to any one of claims 6 to 9 that undergoes a reflow process.
The reflow step includes heating in the preheat zone and heating in the reflow zone.
In the preheat zone, the set temperature is 140 to 170 ° C. and the processing time is 1 to 3 minutes.
In the reflow zone, an electronic component having a set temperature of 180 to 210 ° C., a processing time of 30 to 120 seconds, an actually measured average temperature of 183 ° C. or higher, and an actually measured peak temperature of 220 to 270 ° C.

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