JPH05239344A - Resin composition and electronic part made thereof - Google Patents

Abstract

PURPOSE:To provide an electronic part composed of a nylon 46 resin composition having suppressed water-absorptivity, improved dimensional accuracy and dimensional stability and high reflow-soldering property. CONSTITUTION:The objective resin composition is composed of (A) a nylon 46 resin, (B) an aromatic polysulfone resin [the sum of A and B is 20-78wt.% and the ratio of A/(A+B) is 0.1-0.4], (C) 10-30wt.% of a halogenated compound, (D) 2-10wt.% of antimony oxide and (E) 10-40wt.% of glass fiber. The obtained composition is suitable for surface-mounting electronic part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition, more specifically, a flame retardant glass fiber reinforced polytetramethylene adipamide (nylon 46) exhibiting excellent water absorption characteristics, dimensional characteristics, and reflow solderability. TECHNICAL FIELD The present invention relates to a resin composition for surface mounted electronic components, and a surface real layer compatible electronic component comprising the same.

[0002]

2. Description of the Related Art In the field of electronic parts, with the recent miniaturization and high performance of electric appliances, and also as a method of mounting various electronic parts on a board in order to improve productivity, the mounting density of parts is also increased. The surface mounting method (SMT method), which is high and efficient, is spreading. For this reason, the resin material for electronic parts corresponding thereto is required to have improved mechanical strength and fluidity at the time of molding for downsizing and thinning.

Further, in this surface mounting method, since it is a soldering method by heating far infrared rays in a reflow furnace, it is heated from above an electronic component material such as a connector, and therefore, compared with the conventional mounting method. More severe temperature conditions.

That is, it is required to improve heat resistance of resin materials for electronic parts corresponding to them, and polyamide resins such as nylon 6 resin and nylon 66 resin, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, etc. Conventional materials lack heat resistance.

The application of polyphenylene sulfide resin, aromatic polyamide resin, or the like as a resin material for the surface mountable electronic parts has been examined. Although these resins have excellent heat resistance, they have the above-mentioned mechanical characteristics and flow characteristics. However, there is a limitation in industrial use because of the drawbacks.

As described above, excellent mechanical characteristics, flow characteristics,
There is a strong demand in this field for resin materials for surface-mountable electronic components that also have heat resistance.

Nylon 46 resin has attracted attention as a material that can meet this demand.

Nylon 46 resin is a resin obtained from tetramethylenediamine or a functional derivative thereof and adipic acid or a functional derivative thereof, and has excellent heat resistance and mechanical properties such as tensile strength and bending strength and flow characteristics. Because it is also excellent, it is considered to have great utility value as a useful engineering plastic. As a material for electronic parts, use of a halogenated compound and a composition in which flame retardancy is imparted by a metal oxide, including a reinforced system by glass fiber, is being proposed (Japanese Patent Laid-Open Publication No. 6-58242).
1-188846, 61-188872, 63-5
1456, 63-118368, 63-12807
3, the same 63-139942, the same 63-161056, the same 63-195907, the same 63-195909, the same 63-
223060, 63-3317552, 54-111
58, etc.).

However, this nylon 46 resin has a drawback that it has a higher water absorption rate because it has a higher proportion of amide groups than ordinary polyamide resins such as nylon 6 resin and nylon 66 resin. This means that nylon 46 resin has better heat resistance and mechanical properties than general polyamide resin in the dry state immediately after molding, but has higher water absorption rate than normal polyamide resin in actual use , The deterioration of mechanical properties is larger than those,
In some cases, the superiority of nylon 46 resin will be lost. Also, the high water absorption means that the dimensional change is large. Nylon 46 resin has a smaller dimensional change rate per water absorption rate than general polyamide resins,
Since the water absorption rate is high, the dimensional accuracy is not always at a satisfactory level, and improvement is required to apply it to parts that require high accuracy.

Furthermore, when mounting on a substrate by the surface mounting method using a reflow furnace as described above, electronic components made of nylon 46 resin in a dry state exhibit heat resistance, but in a water absorbing state, the surface of the components may be exposed in some cases. Since damage called blisters appears and the value as a component is significantly reduced, the condition range of the surface mounting method is narrowed. That is, the electronic component made of nylon 46 resin is inferior in reflow soldering property due to the defect in the water absorption property of nylon 46 resin, and it is a great factor in utilizing the excellent heat resistance of this resin as a material for surface mount compatible electronic components. It is an obstacle.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and its purpose is to obtain excellent water absorption characteristics, dimensional characteristics,
It is an improvement of a nylon 46 resin composition as a surface mounting-compatible electronic component material exhibiting reflow solderability, and an object thereof is to provide a surface mounting-compatible electronic component having an excellent function.

[0012]

The present inventors have conducted extensive studies to improve the water absorption characteristics, dimensional characteristics and reflow resistance of flame retarded glass fiber reinforced nylon 46 resin, and as a result, flame retarded glass fiber reinforced nylon. The inventors have found that a composition obtained by blending 46 resins with a specific amount of a specific polymer meets the above-mentioned object and can provide an electronic component compatible with surface mounting, and arrived at the present invention.

That is, the resin composition of the present invention comprises 20 to 78% by weight of (A) nylon 46 resin and (B) aromatic polysulfone resin, and (C) 10 to 3 halogenated compounds.
0% by weight, (D) 2 to 10% by weight of antimony oxide, and (E) 10 to 40% by weight of glass fiber, and of the component (B) in the total amount of the components (A) and (B). A resin composition having a weight ratio in the range of 0.10 to 0.40 and an electronic component made of the resin composition.

The present invention will be described.

The electronic component of the present invention is intended to be a component which is formed by the surface mounting method (SMT method) when soldering on a substrate.

The surface mounting method is a method for mounting an electronic component on a wiring board, in which a lead of the electronic component is passed through a through hole of the substrate and is directly soldered (flow soldering) to the surface opposite to the surface on which the electronic component is mounted. In contrast to the conventional insertion mounting method of wave soldering), electronic components are placed on the printed and printed solder on a wiring board, and the solder is melted by passing the board through a heating furnace called a reflow furnace. Is a method of fixing. According to this surface mounting method, mounting density can be increased, both front and back surfaces can be mounted, and various advantages such as cost reduction due to efficiency improvement can be produced. For this reason, the soldering method is becoming the mainstream in light of the recent trend toward light, thin, short and small electronic devices, high functionality, low price, etc., and its application fields are camera-integrated VTRs, calculators, cameras, watches, LCD TVs,
Consumer electronic devices such as electronic games and handy personal computers, industrial electronic devices such as computers, office computers, workstations, personal computers, peripheral devices, end devices, measuring instruments, etc.
Further, it is an aerospace device.

As a method of heating the substrate in the reflow furnace in the surface mounting, a heat conduction system in which the substrate is placed on a heat-resistant belt moving on a heater and heated, a boiling point is about 22.
VPS method that uses latent heat at the time of coagulation of 0 ° C. fluorine-based liquid, hot air convection heat transfer method in which hot air is forced to circulate through the substrate, and far infrared rays heat the substrate from above or from both upper and lower surfaces. There is a far-infrared system, a system in which heating with hot air and heating with far-infrared are used in combination, and the far-infrared system and the hot-air convection heat transfer system are often adopted due to reasons such as running costs. In these heating methods, unlike the conventional insertion mounting method, the mounted component is also heated to the solder melting temperature, which is a very severe condition for the resin material used for the electronic component.

Specific examples of these surface-mountable electronic components include connectors, switches, volumes, capacitors, ICs, relays, resistors, LEDs, and other components, and cases made of resin. However, the present invention is not limited to the above, and covers all resin electronic components mounted on a substrate by a surface mounting method.

The component (A) nylon 46 resin used in the present invention is a polyamide obtained by a condensation reaction using adipic acid or its functional derivative as the acid component and tetramethylenediamine or its functional derivative as the amine component. However, a part of the adipic acid component or the tetramethylenediamine component may be replaced with another copolymerization component.

Preferred embodiments of nylon 46 resin are JP-A-56-149430 and JP-A-56-1494.
No. 31 publication.

The nylon 46 resin used in the present invention is
In the electronic component, it is desirable that the intrinsic viscosity number when measured with m-cresol at 35 ° C. is in the range of 0.90 to 1.90, more preferably 1.10 to 1.50.

Nylon 46 with an intrinsic viscosity exceeding 1.90
When a resin is used, the fluidity during molding of the electronic component is poor, the gloss of the appearance of the obtained electronic component is lost, and the variations in its mechanical properties and thermal properties become large, which is not preferable. On the other hand, if the intrinsic viscosity is lower than 0.90, the mechanical strength of the electronic component will be reduced.

The component (B) aromatic polysulfone resin used in the present invention is a polymer having an aromatic bond, an ether bond, and a sulfone bond as essential bond units.

These are, for example, Japanese Patent Publication No. 40-1006.
No. 7, 42-7799, 47-617, etc., condensation reaction of an alkali phenolate group and an aromatic halogen group activated by an electron-withdrawing sulfone group in an aprotic polar solvent, etc. Can be easily manufactured.

Specific examples of the aromatic polysulfone resin include
The following general formula (Formula 1)

[0026]

[Chemical 1]

It can be illustrated.

The halogenated compound of the component (C) used in the present invention is generally used as a flame retardant, and bromine and chlorine are preferable as the halogen.

Specific examples of the halogenated compound include brominated polystyrene, brominated polyphenylene ether, brominated phenoxy, brominated epoxy, brominated bisphenol-A-diglycidyl ether and its oligomer, brominated bisphenol- Polycarbonate oligomers produced from A as a raw material, brominated bisphenol ethers, brominated diphthalimide compounds, dimers of chlorinated hexapentadiene and the like can be exemplified as representative ones, but among them, brominated polystyrene is particularly preferable.

This brominated polystyrene is one in which a bromine atom is bonded to the aromatic ring of polystyrene, and is produced by polymerizing brominated styrene or brominating polystyrene. Further, brominated polystyrene can be used even if another vinyl compound is copolymerized. In this case, examples of the vinyl compound include styrene and α-methylstyrene. The polymerization degree of this brominated polystyrene is not particularly limited, but the weight average molecular weight is 100.
Those having an amount of 00 to 1,000,000 are preferably used.

The content of the halogenated compound in the resin composition is 10 to 30% by weight. If the blending amount is less than 10% by weight, the flame-retardant effect of the nylon 46 resin is insufficient,
If the content exceeds 50% by weight, the mechanical properties and thermal properties which are the characteristics of nylon 46 resin will be impaired, which is not preferable.

The antimony compound of the component (D) used in the present invention functions to increase the flame retardancy of the nylon 46 resin by a synergistic effect with the halogenated compound of the component (C).

Examples of the antimony compound include antimony trioxide, antimony tetroxide, antimony pentoxide, sodium antimonate and the like, but antimony trioxide is particularly preferably used.

These flame retardant aids may be used alone or in combination of two or more compounds.

The amount of these flame-retardant aids to be blended is appropriate when the ratio of one metal atom such as antimony to 2 to 5 halogen atoms of the halogenated compound of the component (C) is the present invention. It is 2 to 10% by weight based on the resin composition. When the amount is less than 2% by weight, the effect as a flame retardant aid is small, and when the amount is more than 10 parts by weight, the effect is not expected to be increased by further addition, and the mechanical properties and flowability of nylon 46 resin are not expected. It is not preferable because the moldability such as properties becomes poor.

The glass fiber of the component (E) used in the present invention is added for the purpose of enhancing the mechanical strength and heat resistance of the resin composition and electronic parts, and is generally used for strengthening the resin. If there is no particular limitation. For example, long fiber type (glass roving), short fiber chopped strand, milled fiber, etc. can be selected and used. Further, the glass fibers may be treated with a sizing agent (eg, polyvinyl acetate, polyester sizing agent, etc.), a coupling agent (eg, silane compound, boron compound, titanium compound, etc.) and other surface treatment agents. Usually, long-fiber type glass fibers are cut into a desired length before or after blending with a resin, and this mode of use is also useful in the present invention.

The glass fiber content is 1 in the resin composition.
It is 0 to 40% by weight. If the blending amount is less than 10% by weight, the effect of improving the mechanical strength and heat resistance of the molded product is not sufficient. On the other hand, if it exceeds 40% by weight, the fluidity of the composition in the molten state is significantly deteriorated, so that a molded article having a good appearance cannot be obtained, and the strength is saturated, which is not preferable. ..

The composition in which a halogenated compound, antimony oxide and glass fiber are blended with nylon 46 resin has high strength,
Although it is an excellent electronic component that has excellent heat resistance and the electronic components made of it have sufficient heat resistance to withstand the surface mounting method, nylon 46 resin absorbs moisture in the atmosphere in actual use and is based on moisture absorption. Dimensional change and strength reduction occur. On the other hand, the composition in which the above-mentioned aromatic polysulfone resin is further mixed as the composition has a reduced water absorption rate, and not only has excellent dimensional characteristics as an electronic component, but also has improved solder resistance in a water absorption state. It was found that the above effect was exhibited.

Further, the aromatic polysulfone resin is originally low in compatibility with the polyamide resin such as nylon 46 resin, and the mechanical properties of the mixture of both are low. Therefore, an attempt to improve the compatibility of the both by blending the third component is found in JP-A-2-189360 and the like, but when the composition of the present invention is blended with an aromatic polysulfone resin, its mechanical properties are not impaired at all. I got the unexpected result.

The blending amount of the aromatic polysulfone resin of the component (B) used in the present invention is the same as that of the nylon 46 of the component (A).
The weight ratio in the total amount with the resin is in the range of 0.10 to 0.40. When this ratio is less than 0.10, the effect of suppressing the dimensional change due to water absorption of the composition is not sufficient, and when it is more than 0.40, the mechanical properties of the composition deteriorate, which is not preferable.

If desired, pigments and other compounding agents may be added to the resin composition of the present invention in an expression amount. Such compounding agents include fillers such as aramid fibers other than glass fibers, carbon fibers, steel fibers, asbestos, ceramic fibers, potassium titanate whiskers, fibrous substances such as boron whiskers, kaolin, clay, wollastonite, Examples are powdery, granular or plate-like inorganic fillers such as talc, mica, calcium carbonate, barium sulfate, glass beads and glass flakes.

These fillers are usually blended as a reinforcing material, a surface modifying material, or for the purpose of modifying electrical and thermal characteristics, etc. It should be blended within a range that does not lose the excellent properties inherent to the product and the advantages in molding.

Further, for the purpose of improving heat resistance, an antioxidant or a heat stabilizer such as a copper compound such as copper iodide, a hindered phenol compound, an aromatic amine compound, an organic phosphorus compound or a sulfur compound may be added. .. In addition, various epoxy compounds, oxazoline compounds and the like may be added for the purpose of improving melt viscosity stability and hydrolysis resistance. Examples of epoxy compounds include bisphenol
Bisphenol-A type epoxy compound obtained by reacting A with epichlorohydrin, aliphatic glycidyl ether obtained from reaction of various glycols or glycerol with epichlorohydrin, novolac type epoxy compound,
Aromatic or aliphatic carboxylic acid type epoxy compounds, alicyclic compound type epoxy compounds and the like are preferable, and as the oxazoline compound, aromatic or aliphatic bisoxazoline,
Especially 2,2'-bis (2-oxazoline), 2,2'-
m-Phenylenebis (2-oxazoline) is preferred.

Other stabilizers, colorants, lubricants, ultraviolet absorbers and antistatic agents can also be added.

Further, a small amount of other thermoplastic resin such as other polyamide resin, polyester resin, polyphenylene sulfide resin, polyphenylene ether resin, polycarbonate resin, phenoxy resin, polyethylene and its copolymer, polypropylene and its copolymer weight. Coalesce, polystyrene and its copolymers, acrylic resins and acrylic copolymers, polyamide elastomers, polyester elastomers, etc .; even if thermosetting resins such as phenol resins, melamine resins, unsaturated polyester resins, silicone resins, etc. are blended Good.

Any compounding method can be used to obtain the resin composition of the present invention.

It is usually preferable to disperse these orientation components more uniformly, and all or a part of them may be simultaneously or separately prepared, for example, by a blender, a kneader, a roll,
A method of mixing and homogenizing with a mixer such as an extruder, or a part of the mixing portion is mixed simultaneously or separately with, for example, a blender, a kneader, a roll, an extruder, and the remaining components are mixed or extruded with these mixers. A method of mixing and homogenizing with a machine can be used. Further, there is a method in which a composition dry-blended in advance is melt-kneaded with a heated extruder to homogenize it, then extruded into a wire shape, and then cut into a desired length to granulate.

The molding composition produced in this way is
Usually, it is kept in a sufficiently dried state and put into a hopper of a molding machine to be used for molding such as injection molding. It is also possible to dry-blend the constituent raw materials of the composition and directly put them into the hopper of the molding machine and melt-knead them in the molding machine.

[0049]

The present invention will be described in detail below with reference to examples. In addition,
Various properties in the examples were measured by the following methods.

(1) Mechanical strength: tensile test is ASTM
D638 and impact test conform to ASTM D256 (with Izod and notch).

(2) Deflection temperature under load (HDT): AST
Conforms to MD648 (load 1.84 MPa).

(3) Water absorption property: 80 ° C., relative humidity 95%
Calculated from the increase in weight after standing for 6 hours in the atmosphere (molded product thickness 3.2 mm).

(4) Dimensional characteristics: 80 ° C., relative humidity 95%
Calculated from the dimensional change after standing in the atmosphere for 6 hours (molded product thickness 3.2 mm).

(5) Flammability: Evaluated by the method (UL94) established by Underwriters Laboratories, USA (thickness 0.79 mm).

(6) Intrinsic viscosity: Measured at 35 ° C. with an Ostwald viscous tube using m-cresol as a solvent.

[0056]

Examples 1-2 and Comparative Examples 1-3 110 ° C, 1.3k
Nylon 46 resin with an intrinsic viscosity of 1.34 dried under a reduced pressure of Pa for 12 hours ("STANYL" DSM of the Netherlands)
Company) and polyether sulfone resin ("VICTREX
3600G "manufactured by ICI), brominated polystyrene (" Pyrocheck 68-PB "manufactured by Nissan Ferro Organic Chemical Co., Ltd., antimony trioxide)" Patox C "manufactured by Nippon Seiko Co., Ltd.), and diameter 10 0.5 μm and length 3 mm
Glass fiber chopped strands (manufactured by Nippon Electric Glass Co., Ltd.) were uniformly mixed in a tumbler in advance in a volume ratio shown in Table 1, and then evacuated to a vacuum using a vented twin-screw extruder with a screw diameter of 44 mm. While the cylinder temperature is 3
40 ° C, screw rotation speed 160 rpm, discharge amount 40 kg
/ H, the thread discharged from the die was cooled and cut to obtain molding pellets.

Next, using the pellets, an injection molding machine with an injection capacity of 5 ounces was used to obtain various properties under the conditions of a cylinder temperature of 300 ° C., a mold temperature of 120 ° C., an injection pressure of 80 MPa, a cooling time of 15 seconds, and a total molding cycle of 40 seconds. A molded article for measurement was molded.

Each characteristic was measured using these molded articles. Prior to measurement, the molded product should comply with JIS K7100
Conditioning was performed for 88 hours in an atmosphere of ° C and relative humidity of 50%.

Flame-retardant nylon 46 reinforced with glass fiber
The resin is a composition showing excellent strength and heat resistance, but has a drawback that its water absorption is high and the dimensional change due to water absorption is large (Comparative Example 1).

By blending the above-mentioned polyether sulfone resin with this nylon 46 resin composition, a composition in which water absorption is reduced and dimensional change due to water absorption is suppressed without impairing mechanical properties and heat resistance of the composition is obtained. It is possible (Examples 1-2).

When the amount of the polyether sulfone resin to be blended is small, the effect of improving the water absorption characteristics and dimensional characteristics is not sufficient (Comparative Example 2).

For testing the solder resistance when used as an electronic component, pellets having the composition shown in Table 1 prepared by the above method were used and an injection molding machine with an injection capacity of 1 ounce was used to measure a cylinder temperature of 300. C., mold temperature 120.degree. C., injection pressure 90 MPa, cooling time 10 seconds, and total molding cycle 20 seconds, to form a plate-shaped molded product having a wall thickness of 0.5 mm.

The molded articles were conditioned at 80 ° C. and 95% relative humidity for 1 hour to promote water absorption to obtain water-absorbed molded articles.

The reflow soldering resistance test of the molded articles made of the various compositions obtained by the above method was carried out by a desktop simple reflow furnace (manufactured by Toyo Denso Co., Ltd.). The heating temperature pattern was set so that it was preheated at 150 ° C. for 180 seconds and then heated at a desired temperature for 20 seconds, and the reflow soldering temperature was determined by measuring the surface temperature of the substrate with a thermocouple. The reflow soldering resistance was evaluated by the presence or absence of blisters on the surface of the molded product after heating in a reflow furnace.

The results are also shown in Table 1.

Flame-retardant nylon 46 reinforced with glass fiber
The molded product made of resin has excellent reflow soldering property, but in the water absorption state, the soldering temperature is lower than in the absolutely dry state and is about 240 ° C. (Comparative Example 1).

However, in the case of a molded article made of a composition containing a polyether sulfone resin, the deterioration of the reflow soldering property in the water absorbing state is suppressed, and the composition has excellent soldering resistance (Examples 1 to 1). 2).

Since the mechanical properties of the polyether sulfone resin are deteriorated as the blending amount of the polyether sulfone resin increases, the blending amount is the weight ratio of the polyether sulfone resin in the total amount of the nylon 46 resin and the polyether sulfone resin. 0.40 is the upper limit (Comparative Example 3).

[0069]

[Table 1]

Claims (3)

[Claims] 1. A total amount of 20 to 78% by weight of (A) nylon 46 resin and (B) aromatic polysulfone resin, (C).
Halogenated compound 10 to 30% by weight, (D) antimony oxide 2 to 10% by weight, and (E) glass fiber 10 to 40
And the weight ratio of the component (B) in the total amount of the components (A) and (B) is 0.10 to 0.4.
A resin composition having a range of 0. 2. The resin composition according to claim 1, wherein the component (C) is brominated polystyrene. 3. An electronic component comprising the resin composition according to claim 1 or 2.