JP3484216B2 - Electronic component exterior resin composition - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition used for an exterior of an electronic component, and more particularly, to a resin composition for preventing the electronic component from being automatically inserted into a printed circuit board. The present invention relates to an exterior resin composition for protecting parts. 2. Description of the Related Art In recent years, with the increase in density and labor saving of printed boards, when electronic components are loaded on the printed boards, insertion by an automatic insertion machine has become mainstream. However, in such a loading method, a strong impact is given to the electronic component at the time of insertion, so that the lead portion of the electronic component and sometimes the main body of the electronic component are often damaged or cracked. As a resin composition coated on the surface to protect electronic components, a composition containing a thermosetting resin and a filler is used. As the filler, powders such as silica, alumina, and calcium carbonate are used. Has been used. However, a resin composition using such a filler has not been able to solve the problem of impact at the time of automatic insertion into a printed circuit board as described above. For example, JP-B-62-25185 discloses a dip coating powder resin composition containing 5 to 20% by weight of a solid thermosetting resin composed of a resol type phenol resin and an epoxy resin. Examples of the filler include quartz, alumina, hydrated alumina, calcium carbonate, kaolin, clay, talc, and mica powder. However, such a composition needs to have a resin composition that reduces the drying property in order to increase the impact resistance, and has not yet satisfied both the impact resistance and the drying property. [0005] Japanese Patent Publication No. 3-49945 discloses the use of a fused silica powder and / or a sintered aluminum silicate powder as a main component as a filler of a resin composition for dip coating. Since such a filler has a low coefficient of thermal expansion, it has the characteristic of withstanding heat shock, but cannot withstand the impact of automatic insertion. Japanese Unexamined Patent Publication (Kokai) No. 62-193237 discloses that a heat-resistant organic fiber such as an aromatic amide fiber is combined with a thermosetting resin as an exterior resin of a ceramic element. Although excellent heat shock resistance can be obtained by this, the impact resistance has not been solved yet. SUMMARY OF THE INVENTION An object of the present invention is to provide an electronic component with impact resistance that can withstand the impact of automatic insertion of the electronic component into a printed circuit board. An object of the present invention is to provide a resin composition for exterior having a property. Means for Solving the Problems As a result of repeated studies to achieve the above object, the present inventors have achieved the object by using a specific ratio of glass fiber in the filler. The inventors have found that the present invention can be performed, and have achieved the present invention. That is, the present invention provides a resin composition for an electronic component exterior containing a thermosetting resin and a filler, wherein the total amount of the thermosetting resin and the filler is 50 to 95.
5% to 50% by weight of the filler
But regarding impact electronic component exterior coating and a length of glass fibers 50~70μ m. The thermosetting resin used in the present invention imparts mechanical properties, moisture resistance, heat resistance and electrical insulation to the composition of the present invention, and includes phenolic resins, epoxy resins, unsaturated polyesters, alkyds. Resins, silicone resins, melamine resins, urea resins, polyurethanes, and the like can be used. They may be used alone or in combination of two or more, and are selected according to the required mechanical properties and heat resistance. A feature of the present invention is that 5 to 50% by weight, preferably 10 to 30% by weight of glass fiber is used in the filler. 5% by weight of glass fiber
If the amount is less than 50% by weight, the effect of increasing the strength of the coating film after curing and imparting impact resistance to the electronic component is not sufficient.
The apparent viscosity of the uncured resin composition significantly increases, the workability at the time of application is poor, and a coating film having a uniform thickness cannot be obtained. The glass fibers used in the present invention preferably have a length of 10 to 500 μm, and have a length of 30 to 200 μm.
Are more preferred. If it is less than 10 μm, the fibers are hardly entangled, and the strength of the coating film is not sufficiently improved. Also, 5
If it exceeds 00 μm, the dispersibility of the glass fiber is poor, and the appearance of the coating film tends to be abnormal. Glass fiber diameter is 1 ~
It is preferably 30 µm, more preferably 3 to 20 µm.
If it is less than 1 μm, the strength of the glass fiber is weak and sufficient coating film strength cannot be obtained. If it exceeds 30 μm, the glass fiber is less likely to be entangled in the resin composition. The type of glass fiber is not particularly limited, but non-alkali glass, acid-resistant glass,
Glasses such as alkali-containing glass and silica glass are exemplified, and alkali-free glass is preferable. [0013] Such a glass fiber is suitably obtained, for example, by grinding a glass filament to a desired length. In order to improve the adhesiveness with the resin, as a silane coupling agent, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane,
N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyl Methyldimethoxysilane, 2,3-epoxycyclohexylethyltrimethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, 3-methacryloxypropyl The surface treatment is preferably performed using a carbon-functional silane compound such as trimethoxysilane or 3-methacryloxypropylmethyldimethoxysilane. Such a surface treatment may be applied to the glass fiber in advance,
When preparing a resin composition by mixing with a thermosetting resin, it may be performed by blending the carbon-functional silane compound. By using such glass fiber,
Glass fibers are entangled in the resin composition to improve the strength of the cured coating film, and particularly to impart excellent impact resistance to the coating film.
In addition, when the resin composition is dissolved and dispersed in an organic solvent and used for exterior processing of an electronic component, there is also an effect of speeding up drying of the solvent after the processing. In the present invention, the other filler used in combination with the glass fiber is not particularly limited, but powders such as silica, alumina, calcium carbonate, kaolin, clay, talc, and mica are exemplified, and silica is preferred. . The total amount of such a glass fiber and a filler composed of another filler is 50 to 95% by weight, preferably 70 to 95% by weight of the total amount of the thermosetting resin and the filler. When the amount of the filler is less than 50% by weight, the drying property of the coating film is poor, and when it exceeds 95% by weight, the strength of the coating film cannot be obtained. Here, the amount of the thermosetting resin is an amount excluding the solvent when the resin contains a solvent, and the amount of the curing agent and / or
Alternatively, for those containing a reactive monomer, the amount includes them. The resin composition of the present invention may further contain, if necessary, additives such as a curing agent, a curing accelerator, an anti-sagging agent, a thickener, an antifoaming agent, a pigment and a dye in an appropriate amount. can do. The resin composition of the present invention may be used as it is or together with any of the above-mentioned additives as a powder coating for the exterior of electronic components. An organic solvent is added to these components to dissolve the organic resin. The filler may be dispersed and used similarly as a flowable paint. The solvent is not particularly limited, and depends on the use and the type of the thermosetting resin, a hydrocarbon solvent such as petroleum hydrocarbon, toluene, xylene, mesitylene and tetralin; an ether solvent such as tetrahydrofuran; Ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and isophorone; alcohols and ethers such as isopropyl alcohol, butyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether and diethylene glycol monobutyl ether Examples thereof include alcohol solvents; and ester solvents such as ethyl acetate and butyl acetate, and one or more solvents may be used. The resin composition of the present invention, or a paint containing an additive and / or a solvent as required,
It can be prepared by uniformly mixing an uncured thermosetting resin, glass fiber and other fillers, and other optional components using a stirrer, kneader, roll, or the like, in a conventional manner. The resin composition of the present invention can be used for electronic parts.
Coating is performed by an immersion method or the like, and when a solvent is contained, the solvent is dried and then heat-cured according to the curing temperature of the thermosetting resin to obtain an exterior coating film. By [0021] the present invention, the outer coating is obtained which gives the impact resistance of the outer coating film excellent in surface of the electronic component. The electronic components packaged with the coating composition of the present invention are printed.
It can withstand the impact of automatic insertion into the board . Further, when the resin composition of the present invention is used in the presence of a solvent, the drying of the solvent is accelerated and the process is shortened as compared with the conventional composition. Therefore, the exterior coating material of the present invention is extremely useful as an exterior coating material for electronic components inserted into a printed circuit board such as a capacitor, in particular, for electronic components with leads. The present invention will be described below in more detail with reference to Examples and Comparative Examples. The present invention is not limited by these examples. In Examples and Comparative Examples, all parts are by weight. In addition, the test used for the Example was performed by the following method. After air-drying the prepared resin composition, it is applied to the surface of a disk-shaped ceramic capacitor having a diameter of 16 mm.
The sample was left in an atmosphere of% RH, and the time required for the solvent to evaporate, the surface to dry and to become a tack-free state was measured. Ball Fall Impact Strength The prepared resin composition was applied to the surface of a film coated with a release agent by an applicator to form a coating film. This was air-dried, peeled off, and cured by heating at 150 ° C. for 30 minutes to produce a test piece having a size of 20 mm × 30 mm and a thickness of 1 mm. This test piece was placed on an iron plate and weighed 25 g from above.
Was dropped, and the height when the test piece was broken was determined. Examples 1 to 4; Comparative Examples 1 to 3 Resin compositions of Examples 1 to 4 containing glass fibers as fillers, Comparative Examples 1 and 2 containing no glass fibers, and compositions shown in Table 1 3.3% by weight of glass fiber in filler
The contained resin composition of Comparative Example 3 was prepared by uniformly mixing the components using a stirrer. With respect to these resin compositions, coating films and test pieces were prepared by the methods described above, and the air-drying property and the ball impact drop strength were measured. Table 1 shows the results. [Table 1] Comparative Example 4 20 parts of silica powder used in Example 1, glass fiber (A)
A resin composition was prepared in the same manner as in Example 1 from 40 parts, 4 parts of epoxy resin, 4 parts of phenol resin, 1 part of silane coupling agent, 5 parts of titanium oxide, 2 parts of fumed silica and 24 parts of methyl ethyl ketone. Using the composition,
An attempt was made to form a coating film in the same manner as in Example 1. However, since the apparent viscosity was remarkably high, workability was poor, a uniform coating film was not obtained, and a test piece for measuring ball drop impact strength was prepared. I couldn't.

Claims (1)

(57) [Claim 1] In a resin composition for an electronic component exterior containing a thermosetting resin and a filler, 50 to 50% based on the total amount of the thermosetting resin and the filler. It contains 95% by weight of filler, of which 5 to 50% by weight have a length of 50 to 70 μm.
m impact-resistant electronic component exterior paint that is glass fiber.