JP3037361B2 - Molded product with metal terminals etc. inserted - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a resin molded product obtained by inserting a metal terminal such as a lead frame and a frame thereof. More specifically, the present invention particularly relates to a molded product obtained by inserting a metal terminal such as a lead frame having excellent adhesion to a metal, excellent heat resistance, excellent moldability, and excellent general physical properties, and a frame thereof. .

[Conventional technology and its problems]

In order to mount electronic components on a printed wiring board, the method of passing the terminals of electronic components through holes in the substrate and soldering the terminals from the back side of the substrate has become widespread. Opportunities are increasing.

Thermoplastic polyesters such as polyalkylene terephthalate are widely used for electronic parts such as switches and IC packages because of their excellent workability, mechanical strength and other physical and chemical properties. I have.

However, since polyalkylene terephthalate has poor adhesion to metals such as lead frames, the solder flux used for soldering and the cleaning liquid used for cleaning electronic components penetrate through the gap between the lead frame and plastic. However, problems such as contact contamination and poor conduction have occurred.

Similarly, the connector electrode has poor airtightness due to poor adhesion to metal, and has a problem of contamination due to intrusion of moisture and the like.

Conventionally, in order to solve this problem, after applying a primer, an adhesive, or the like to a metal such as a lead frame, the metal is molded or formed. Measures such as potting epoxy resin have been taken.

However, such a method requires a complicated process and significantly increases the cost. Therefore, a material that has good adhesion to a metal such as a lead frame and is easily formed is desired.

[Means for solving the problem]

In view of the above problems, the present inventors have intensively studied to obtain a material such as a lead frame having excellent adhesion to metal. As a result, a composition comprising a thermoplastic polyester as a main component and a specific copolymer and an inorganic filler added thereto has good heat stability, and at the extrusion and molding temperatures of the polyester resin, almost no decomposition gas or evaporation gas is generated. It has been found that this does not occur and that the adhesion to a metal such as a lead frame can be remarkably improved without a large decrease in mechanical properties, and the present invention has been completed.

That is, the present invention relates to (A) 100 parts by weight of a thermoplastic polyester resin, (B) ethylene-ethyl acrylate copolymer, ethylene-ethyl acrylate-maleic anhydride terpolymer, and ethylene-grafted maleic anhydride. 1 to 50 parts by weight of at least one ethylene copolymer selected from ethyl acrylate copolymer and (C) 5 to 200 parts by weight of a fibrous filler, a non-fibrous inorganic filler or a mixture of both. It is a molded product obtained by inserting a metal terminal or the like using the above-described resin material.

Hereinafter, the components of the resin material of the present invention will be described in detail.

First, the thermoplastic polyester resin (A) which is a base resin of the resin material of the present invention is obtained by polycondensation of a dicarboxylic acid compound and a dihydroxy compound, polycondensation of an oxycarboxylic acid compound, or polycondensation of a mixture of these three components. The present invention is effective for any of homopolyesters and copolyesters.

Illustrative examples of the dicarboxylic acid compound constituting the thermoplastic polyester resin used here include terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenyletherdicarboxylic acid, diphenylethanedicarboxylic acid, cyclohexanedicarboxylic acid,
Known dicarboxylic acids such as adipic acid and sebacic acid and alkyl, alkoxy or halogen substituted products thereof. These dicarboxylic acid compounds can also be used for polymerization in the form of a derivative capable of forming an ester, for example, a lower alcohol ester such as dimethyl ester. Two or more of these may be used.

Next, examples of the dihydroxy compound constituting the polyester (A) of the present invention include ethylene glycol, propylene glycol, butanediol, neopentyl glycol, hydroquinone, resorcin, dihydroxyphenyl, naphthalene diol, dihydroxydiphenyl ether, cyclohexanediol, , 2-bis (4-hydroxyphenyl) propane, dihydroxy compounds such as diethoxylated bisphenol A, polyoxyalkylene glycols and their alkyl, alkoxy, or halogen-substituted products, etc., and it is possible to use one kind or a mixture of two or more kinds. it can.

Examples of oxycarboxylic acids include oxycarboxylic acids such as oxybenzoic acid, oxynaphthoic acid, and diphenyleneoxycarboxylic acid, and alkyl, alkoxy or halogen-substituted products thereof. Further, derivatives of these compounds capable of forming an ester can also be used. In the present invention, one or more of these compounds are used.

In addition, a polyester having a branched or crosslinked structure using a small amount of a trifunctional monomer, that is, trimellitic acid, trimesic acid, pyromellitic acid, pentaerythritol, trimethylolpropane, or the like may be used.

In the present invention, any of the thermoplastic polyesters produced by polycondensation using the above-described compound as a monomer component can be used as the component (A) of the present invention, and can be used alone or as a mixture of two or more. However, preferably, polyalkylene terephthalate, more preferably polybutylene terephthalate and a copolymer mainly composed of polybutylene terephthalate are used.

Next, in the present invention, a specific ethylene copolymer (B) is blended with the thermoplastic polyester resin (A).

The specific ethylene copolymer blended as the component (B) includes ethylene-ethyl acrylate copolymer, ethylene-ethyl acrylate-maleic anhydride terpolymer, and ethylene-ethyl acrylate grafted with maleic anhydride. It is a copolymer. Here, the content of ethyl acrylate is 3 to 35% by weight, preferably 10 to 30% by weight.
Is desirable. If the content of ethyl acrylate is larger than this, not only the production of the copolymer becomes difficult, but also the amount of gas generated during extrusion / molding increases, which is problematic. On the other hand, if the amount is less than this, the adhesion to a metal such as a lead frame tends to be slightly reduced.

When maleic anhydride is copolymerized, its content is used at 10% by weight or less. Exceeding this gives undesirable results such as poor appearance due to yellowing and thermal stability.

Such an ethylene-based copolymer can be produced by any method. For example, an ethylene-ethyl acrylate copolymer can be obtained by mixing a predetermined amount of ethylene and ethyl acrylate and performing radical polymerization by a conventional method using a radical initiator. Also, maleic anhydride is added to the copolymer, preferably in the presence of a radical initiator.
By reacting at ~ 250 ° C, a graft copolymer is obtained.

Further, a terpolymer can be obtained by adding a radical initiator or the like to a mixture of ethylene, ethyl acrylate, maleic anhydride and the like and polymerizing the mixture under pressure.

The addition amount of the component (B) is preferably 1 to 50 parts by weight, particularly preferably 5 to 40 parts by weight, per 100 parts by weight of the thermoplastic polyester (A). If the amount is too small, the adhesion to the metal terminal or the like, which is the object of the present invention, is inferior.

Next, the filler of the component (C) used in the present invention is a component essential for lowering the molding shrinkage and the coefficient of linear expansion and improving the adhesion to a metal such as a lead frame.

For this, a fibrous or non-fibrous (granular, plate-like) filler is used.

Among them, non-fibrous inorganic fillers are used because they have a large effect of suppressing the anisotropy of molding shrinkage, dimensional stability and linear expansion coefficient, and carbon black, silica, and quartz are used as powdery and granular fillers. Powder, glass beads, glass powder, milled glass fiber, calcium silicate, aluminum silicate, kaolin, talc, clay, diatomaceous earth, silicates such as wollastonite, iron oxide, titanium oxide, zinc oxide, alumina Metal oxides, calcium carbonate,
Examples include metal carbonates such as magnesium carbonate, metal sulfates such as calcium sulfate and barium sulfate, and other metal powders such as silicon carbide, silicon nitride, boron nitride.

Examples of the plate-like filler include mica, glass flake, various metal foils, and the like. The smaller the particle diameter of the plate-like material is, the more preferable it is, and the average particle diameter is desirably 200 μm or less.

Among them, as the non-fibrous inorganic filler, glass beads, milled glass fibers, glass flakes and finely divided mica powder are particularly preferred.

The fibrous filler is used for improving performance such as mechanical strength and heat resistance. Examples thereof include glass fiber, carbon fiber, silica fiber, silica / alumina fiber, zirconia fiber, and boron nitride fiber. And inorganic fibrous substances such as silicon nitride fibers, boron fibers, potassium titanate fibers, and metal fibrous materials such as stainless steel, aluminum, titanium, copper, and brass. Particularly typical fibrous fillers are glass fibers or carbon fibers. Note that a high-melting-point organic fibrous substance such as polyamide, fluororesin, or acrylic resin can also be used.

These inorganic fillers can be used alone or in combination of two or more. A particularly preferred combination is a combination of a glass fiber having an average fiber length of 30 to 500 μm in a molded article and a particulate and / or plate-like filler. Among them, the combination of glass beads, milled glass fibers, glass flakes or mica powder with glass fibers has a particularly remarkable effect of improving the adhesion to metals such as lead frames.

In using these fillers, it is desirable to use a sizing agent or a surface treatment agent if necessary. This example is a functional compound such as an epoxy compound, an isocyanate compound, a silane compound and a titanate compound. These compounds may be used after being subjected to a surface treatment or a convergence treatment in advance, or may be added simultaneously with the preparation of the material.

The amount of the filler used as the component (C) is 5 to 200 parts by weight, preferably 10 to 90 parts by weight, per 100 parts by weight of the thermoplastic polyester (A). If the amount is too small, the effect of improving the adhesion to a metal such as a lead frame is small.

The amount of the functional surface treating agent used in combination is 0 to 10% by weight, preferably 0.05 to 5% by weight, based on the filler.

Further, the resin material for inserting the metal terminal or the like of the present invention, in order to further impart desired characteristics according to the purpose,
Known substances generally added to thermoplastic resins and the like, such as antioxidants and heat stabilizers, stabilizers such as ultraviolet absorbers, antistatic agents, lubricants, release agents, coloring agents such as dyes and pigments, and lubricants , A plasticizer, a crystallization accelerator, a crystal nucleating agent, and the like. Further, as the resin component, a thermoplastic resin other than the components (A) and (B) may be used in combination as long as the object of the present invention is not impaired.

In particular, the addition of stability is effective in preventing corrosion and contamination of the metal in contact with electronic parts and the like using molded products at high temperatures.

As the stabilizer, hindered phenol compounds, amine compounds, phosphorus compounds, thioether compounds and the like can be used.

An example of a hindered phenol compound is 1,6
-Hexanediol bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] , Triethylene glycol bis [3- (3-t-butyl-5-
Methyl-4-hydroxyphenyl) propionate].

As an example of an amine compound, N-phenyl-N'-
Isopropyl-p-phenylenediamine, N, N'-diphenyl-p-phenylenediamine, 4,4'-bis- (4
-Α, α-dimethylbenzyl) diphenylamine, a condensation reaction product of diphenylamine and acetone, N-phenylnaphthylamine, N, N′-di-β-naphthylphenylenediamine and the like.

As the phosphorus compound, a phosphite or phosphite-based organic compound is preferable. For example, triallyl phosphite such as triphenyl phosphite and tri (nonylphenyl) phosphite, distearyl pentaerythritol diphosphite, cyclic Heat resistance of neopentanetetrayl-bis- (2,4-di-t-butylphenyl-phosphite), di- (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite Phosphites and phosphonite compounds such as tetrakis (2,4-di-t-butylphenyl) -4,4-biphenylenephosphonite are typical examples.

Further, as thioether compounds, dilauryl thiodipropionate, dimyristyl thiodipropionate,
Distearylthiodipropionate, laurylstearylthiodipropionate, tetrakis [methylene-3-
(Dodecylthio) propionate] methane, and dialkyl (C ₁₂ -C _{18)-3,3-thiodipropionate} and the like.

The amount of stabilizer added is 0.01 to 5% by weight based on the total amount of resin material
And preferably 0.1 to 3% by weight.

The resin material for an insert of the present invention is easily prepared by equipment and a method generally used as a conventional resin composition preparation method. For example, i) after mixing each component,
A method in which pellets are prepared by kneading and extruding with a single-screw or twin-screw extruder and then molded; ii) pellets having a different composition are once prepared, and the pellets are mixed in a predetermined amount and subjected to molding. Iii) a method of directly charging one or more of each component to a molding machine, and the like. Mixing and adding a part of the resin component as a fine powder with other components is a preferable method for uniformly blending these components.

In addition, the above-mentioned resin material can be used to insert a metal terminal, a frame, or the like, and can be molded by a general metal insert injection molding method. That is, a metal terminal such as a lead frame is mounted at a predetermined position in a mold, and the insert molded product of the present invention can be produced extremely efficiently by injection molding.

〔Example〕

Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited thereto.

In addition, the measuring method of the physical property evaluation shown in the following examples is as follows.

Tensile strength and elongation Tensile strength and elongation were measured in accordance with ASTM D-638.

Flexural properties The flexural strength and flexural modulus were measured according to ASTM D-790.

Ink penetration distance (evaluation of adhesion) Using an injection molding machine, a lead frame was set in a mold, and at a cylinder temperature of 260 ° C, a test piece with a lead frame inserted as shown in Fig. 1 was molded. Insert one terminal side of the test piece into a specific fluorescent ink (PEP Fluorescent Penetrant F-6A-S, manufactured by Eishin Chemical Co., Ltd.) up to half the depth of the test piece.
P), and the adhesiveness between the metal lead frame and the resin was evaluated based on the ink penetration distance (l) penetrated between the metal lead frame and the resin by capillary action. The measurable ink penetration distance is 14 mm.

Examples 1 to 14 and Comparative Examples 1 to 9 Polybutylene terephthalate was used as the thermoplastic polyester (A), and various ethylene copolymers (B) and fillers (C) shown in Table 1 were mixed in proportions shown in Table 1. And pellets of the resin material were obtained with an extruder. Next, using this pellet, various test pieces were prepared by injection molding,
The above physical properties were evaluated. For comparison, pellets were prepared in the same manner as in Examples, for those omitting the component (B) and for those using an ethylene propylene copolymer elastomer (B ′) not belonging to the requirements of the present invention as the component (B).
This was evaluated in the same manner as in the examples.

 Table 1 also shows the results.

Example 15 and Comparative Example 10 The test and evaluation were conducted in the same manner as in Example 2 except that the component (A) in Example 2 was changed to a mixed polymer of polybutylene terephthalate and polyethylene terephthalate. Table 1 shows the results. On the other hand, as a comparative example, a sample in which the component (B) was omitted was tested and evaluated in the same manner as in Example 15. The results are shown in Table 1.

Notes in Table 1 (A) Polybutylene terephthalate; intrinsic viscosity 0.75 polyethylene terephthalate; intrinsic viscosity 0.60 (B) B-1; ethylene ethyl acrylate (ethyl acrylate content 25%), NUC 6570 B-2 manufactured by Nippon Unicar Co., Ltd. Ethylene ethyl acrylate (ethyl acrylate content 8%), Nippon Unicar Co., Ltd. DPDJ-826 B-3; maleic anhydride grafted ethylene ethyl acrylate copolymer, Mitsui Dupont Polychemical Co., Ltd. AR-201 B- 4; a terpolymer composed of ethylene-ethyl acrylate-maleic anhydride, manufactured by Sumitomo Chemical Co., Ltd. Bondyne HX8020 (C) glass fiber; manufactured by Asahi Fiber Glass Co., Ltd.
CS03MA419 Milled glass fiber; Nitto Boseki Co., Ltd. PF
B-101 glass beads; Toshiba Barotini Co., Ltd. EG
B731A Glass flake; average flake diameter 600 µm Mica powder; MS325A manufactured by Shiraishi Calcium Co., Ltd. The adhesion between the metal and the resin is good, and it is possible to prevent the solder flex and the cleaning liquid from entering the molded product from the gap between the metal and the resin.

[Brief description of the drawings]

FIG. 1 shows an example of a molded part into which the lead frame of the present invention is inserted. (A) is a plan view, (B) and (C)
Is a side view. FIG. 2 is a partially enlarged view of FIG. 1 (A) showing a measurement unit of the ink penetration test in the embodiment. DESCRIPTION OF SYMBOLS 1 ... Lead frame (made of copper) [black part in drawing] 2 ... Resin part [hatched part in drawing] 3 ... Lead frame terminal 4 ... gate part 5 ... ink penetration test measurement part l ... ink Penetration distance

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ identification code FI C08L 23:08) B29K 67:00 B29L 31:34 C08L 67:02 (58) Fields surveyed (Int.Cl. ⁷ , DB name) ) C08L 67/02 B29C 45/14 C08J 5/00

Claims (3)

(57) [Claims] An ethylene grafted with (B) an ethylene-ethyl acrylate copolymer, an ethylene-ethyl acrylate-maleic anhydride terpolymer and a maleic anhydride with respect to 100 parts by weight of a thermoplastic polyester resin (A). -1 to 50 parts by weight of at least one ethylene copolymer selected from ethyl acrylate copolymer, and (C) 5 to 200 parts by weight of a fibrous filler, a non-fibrous inorganic filler or a mixture of both. A molded product made by inserting metal terminals etc. using the compounded resin material. 2. The thermoplastic polyester resin (A) is a resin mainly composed of polybutylene terephthalate.
A molded product obtained by inserting the metal terminal described above. 3. A molded product obtained by inserting a metal terminal or the like according to claim 1 or 2, wherein at least one of glass beads, milled glass fibers, glass flakes, mica powder and glass fiber are used as the component (C). .