JP4975976B2 - Material for electrical and electronic parts and method for producing the same - Google Patents

Description

The present invention relates to an electrical / electronic device, particularly an electrical / electronic component such as a low-profile built-in housing mounted on a printed circuit board of a portable device, such as a housing, a case, a cover, a cap, a printed circuit board, and a cable. The present invention relates to a metal material suitable for a connector part connected to the connector.

Built-in individual components such as ceramic resonators, crystal oscillators, voltage controlled oscillators, SAW filters, diplexers, couplers, baluns, LPFs, BPFs, dielectric duplexers, etc. mounted on printed circuit boards of electrical and electronic equipment. various module component obtained by, for example, an antenna switch module, a front-end module, RF integrated module, images sensor module, a tuner module, such as a wireless LAN applications, or parts such as the detection switch, metal for electromagnetic shielding It is used by putting it in a case or covering it with a cover. However, with the progress of portability of electric and electronic equipment, the case and the like are required to be thin and low in height. 5mm or less, 2mm for individual parts, and rushing around 1mm That. The terminal connection connector on the printed circuit board side such as a liquid crystal driver (LCD), keyboard, and motherboard and the connection connector on the FPC cable side are required to have electromagnetic shielding properties for the purpose of preventing communication noise and static electricity. Although it is used by being covered with a cap or cover, the devices are similarly becoming smaller and thinner, and connector parts and sockets are also becoming smaller and lower in profile.

However, the above metal casings, etc., have a smaller internal volume as the height is reduced, and the built-in components, terminals, wiring circuits and cases, covers, caps, casings (cases with covers), etc. There was a drawback that sufficient insulation could not be secured.
In such a case, conventionally, as disclosed in Patent Document 1, the insulating film is cut into a sheet-like predetermined size and inserted into the case, or as disclosed in Patent Document 2, a resin is placed on the metal substrate. For example, the film is cut into a predetermined dimension from a metal material on which a film is formed in advance. Using a material in which a resin film is previously formed on a metal substrate is preferable from the viewpoint of productivity and economy because it can be continuously punched and bent, and can be continuously high in quality, such as partly, entirely, or both sides. In recent years, it tends to be frequently used because it is a material capable of forming a film.
Japanese Patent Laid-Open No. 1-6389 JP 2004-197224 A

However, as portable devices and digital devices become smaller and thinner and have higher functionality, the shape of electrical and electronic parts mounted and used on these devices has become considerably limited. For this reason, the processing for obtaining the required shape becomes strict, and for example, when a bending process of 180 degrees is required, a resin film formed on the metal base material that breaks and breaks without being able to withstand bending is also produced. New problems such as coming.
The present invention eliminates the disadvantage that electrical and electronic parts formed from conventional metal materials for electrical and electronic parts cannot ensure sufficient insulation from built-in parts, etc. To provide materials for electrical and electronic parts that are suitable for cases and the like, have sufficient insulation with built-in components, can maintain heat dissipation, and have excellent workability that can withstand highly severe press molding. Objective.

As a result of intensive studies on the insulating properties and workability of materials for electrical and electronic parts, the present inventors have formed a resin film having excellent workability at locations where insulation is required on the metal substrate, and formed from this metal substrate. It has been found that the desired part shape can be obtained, and insulation with the built-in element can be sufficiently secured, thereby achieving the above object. The present invention has been made based on this finding.

That is, the present invention
(1) A resin film having a thickness of 2 μm or more and less than 15 μm is partially formed on at least a part of the metal substrate, and the resin film is coated with a liquid resin paint or a resin varnish on the metal substrate. , A reaction-cured resin film, which is a polyamide-imide resin having an imidization rate of 20% or more, a number average molecular weight of 15000 or more, and an elongation rate until breakage of 20% or more. After bending 90 ° with a bending radius of 0.15 mm, the resin film at the bent portion was broken when the bending portion was further crushed by a press machine at ^2.5 N / mm ² and 180 ° bending was performed. Electrical and electronic parts material, characterized by not
(2) An electric / electronic component using the electric / electronic component material according to (1),
I will provide a.

Electrical and electronic component material according to the invention, partially in a portion at least on a metal substrate, a resin film of 20% or more elongation, the number average molecular weight of 15,000 or more of the resin film, at 15μm thickness less than or 2μm since the formed, for example, when the resin film used in the inside housing, can be easily processed into a desired part shape, sufficiently secure insulation between the internal elements, In addition, it is possible to maintain heat dissipation from a portion where no resin is formed and to perform solder bonding. Therefore, a low-profile and easy-to-shape shape of the housing can be realized, which is useful for thinning portable devices and the like.

The present invention is a polymer resin film is, if Lee imidization ratio with 20% or more of the polyamide-imide resin, the processability, insulating property, in addition to heat dissipation, the other including a heat-resistant A material with good characteristics can be obtained.

In addition, according to the present invention, electrical and electronic parts using a metal base material on which at least a part of these resin films are formed can easily obtain a desired shape such as a low profile and a thin shape, and also have insulation, heat dissipation, and mounting characteristics. It is possible to obtain high reliability and a long component life.

Embodiments of materials for electric and electronic parts according to the present invention will be described below in detail with reference to the drawings.
FIG. 1 is a cross-sectional view in the width direction of an electrical / electronic component material according to the first embodiment of the present invention. A striped resin film 2 is provided on a part of the surface of the metal substrate 1.
The portion having the resin film 2 is preferably a portion that requires insulation. The place that requires insulation is a place that requires insulation of the electrical and electronic parts formed from the metal base material, and by insulating the place with a resin film, insulation between the housing or case and the built-in parts is achieved. Is sufficiently secure, which is advantageous for reducing the height of the housing. For this reason, it is desirable to form the resin film with high accuracy. The resin film 2 may Rukoto provided only at locations requiring insulation. A plurality of stripe-shaped resin films 2 may be formed on the metal substrate 1 as shown in FIG. 7 or may be partially formed as shown in FIG. each also rather good to form a portion, it may have a resin film 2 on a part of the 1 at least a metal substrate. Moreover, since the metal base material is exposed at the location where the resin film 2 is not provided, the heat dissipation is maintained at a high level. 6 and 9 are reference examples.

The present invention, the resin film 2 have a breaking elongation of 20% or more tensile, number the average molecular weight has a higher 15000, it can be applied to the material to demanding part processing applications. Preferably that having a growth rate of 30% or more, the number average molecular weight is applied to more than 20,000 of the resin film it can be used more safely severe working shaped parts.

In the present invention, the resin film 2 is Ru resin film der heat resistance. Tree fat to form a heat-resistant resin coating is port Riamidoimido based resin is used.

When i imidization ratio is 20% or more of polyamideimide, it requires workability insulation, of the addition, heat resistance and adhesion, hygroscopicity, excellent in solvent resistance, good resin film balance A component molding material and an electric / electronic component using the material are obtained. When a polyamideimide having a low imidization rate is used, the cost is low and the economic effect is excellent.

Further, the insulating property of the heat resistant resin film is preferably 10 ¹⁰ Ω · cm or more, more preferably 10 ¹⁴ Ω · cm or more.

These resins have heat resistance against heating processes such as solder bonding and reflow solder mounting .

If the thickness of the heat-resistant resin film is too thin, sufficient insulation cannot be obtained, and pinholes are likely to occur. Therefore, the thickness is preferably 2 μm or more, and more preferably 3 μm or more. On the other hand, if too thick, moldability into a casing or the like is less than 1 5μm in decreasing.

As a production method in the present invention, a resin film formed on a metal substrate and having a number average molecular weight of 15000 or more can be used. For example, after applying their tree butter resin varnish or paint dissolved in a solvent as a predetermined percentage concentration is obtained a on a metal substrate, may be heated and dried baking. Or after apply | coating the resin liquid which does not need to melt | dissolve in a solvent, it can also be made to harden | irradiate by irradiating UV and an electron beam, and can also form a film | membrane on a metal base material. Alternatively, a resin film can be formed by applying a paint prepared by adding a photosensitizer to the resin varnish, and then forming a pattern mask on the entire surface or where insulation is required, followed by exposure and development. By having a number average molecular weight used 15000 trees fat, often elongation can be obtained resin film is 20% or more.

In the second embodiment of the present invention, at least one metal layer is provided on a metal substrate, and the resin film is provided directly or via the metal layer on the metal substrate.

FIG. 2 is a cross-sectional view in the width direction of a material for electrical and electronic parts according to the second embodiment of the present invention.
A heat-resistant resin film 2 is provided on the metal substrate 1 where insulation is required, and a Ni layer 3 is provided on the metal substrate other than the place where the heat-resistant resin film 2 is provided. .
The metal material shown in FIG. 2 has improved corrosion resistance because the Ni layer 3 is provided on the metal substrate 1 other than the portion where the heat resistant resin film 2 is provided.

FIG. 3 is a cross-sectional view in the width direction of another material according to the second embodiment of the present invention.
A heat-resistant resin film 2 is provided at least on the metal base 1 where insulation is required, and the Ni layer 3 and the Sn layer on the metal base 1 other than the place where the heat-resistant resin film 2 is provided. 4 are provided in this order.

FIG. 4 is another cross-sectional view in the width direction according to the second embodiment of the present invention.
A Ni layer 3 is provided on the metal substrate 1, a heat-resistant resin film 2 is provided at a place where insulation is required, and a Ni other than the place where the heat-resistant resin film 2 is provided. An Sn layer 4 is provided on the layer 3.

The material of this embodiment shown in FIGS. 3 and 4 is provided with the Sn layer 4 on the metal substrate 1 other than the place where the heat-resistant resin film 2 is provided. Can be done easily. Moreover, since the diffusion of the metal base 1 component is blocked by the Ni layer 3, the discoloration of the Sn layer 4 is prevented. In addition, since the heat-resistant resin film 2 is provided on the Ni layer 3 for the material of the present invention shown in FIG. 4, the effect of improving the adhesion with the resin film can be obtained.

When the metal layers as shown in FIGS. 3 and 4 are provided in two layers, the metal substrate 1 is well protected, and the heat resistance, oxidation resistance, corrosion resistance and the like of the metal substrate 1 are improved. Further, it is possible to suppress the outer layer of the metal layer from being alloyed or compounded by diffusion of one component of the metal base material. Particularly, in the case where the Ni layer or Cu layer is provided on the base and the Sn layer is provided on the outer layer, compounding of the Sn layer is sufficiently suppressed, and heat resistance and whisker resistance are highly maintained. It is more effective to provide three or more metal layers, but two metal layers are appropriate in terms of cost performance.

As shown in FIGS. 2 to 4, the metal layer may be provided in a single layer or multiple layers. For example, in the case of a solder mounting application, it is desirable that the thickness of the most metal layer among the above metal layers is 1 μm or more that can maintain good solder wettability and can be melt-bonded such as reflow solder bonding. The upper limit is about 20 μm, and the effect is saturated even if the thickness is increased further. In other applications, the thickness of the surface metal layer is most preferably in the range of 0.1 μm to 10 μm from the viewpoint of corrosion resistance and resin adhesion. The metal layer other than the surface layer is preferably in the range of 0.1 μm to 10 μm.
In the case of multiple layers, two layers are more preferable from the viewpoint of cost performance. The thickness of each layer constituting the multilayer is preferably 0.1 μm or more and 10 μm or less.

The material of the metal layer provided on the metal substrate is determined by the material of the metal substrate, the type of parts used, application, required characteristics, allowable cost, etc., but any metal that satisfies the basic required characteristics required in the present invention in any case Is selected. For the metal layer, usually, any one of Ni, Cu, Sn, Ag, Pd, and Au, or an alloy, eutectoid, or compound containing at least one of the metals is used.
From the viewpoint of cost performance, Ni, Sn, Ag systems (metals, alloys, eutectoids, compounds) are used for single-layer coatings, and Ni or Cu are used on the inner layer (underlayer) side for multi-layer coatings. It is preferable to use a Sn, Ag, Pd, or Au system on the outer layer side. In the case of three or more layers, it is preferable to use Cu, Ag, and Pd for the intermediate layer.

An alloy can also be used for the Ni-based or Cu-based underlayer. In addition, a single structure or a single multilayer structure is sufficient. If the thickness is too thin, the number of pinholes increases. If the thickness is too thick, cracks are likely to occur during processing, so about 0.1 to 2 μm is desirable.

A structure in which the base is made of each of one or more layers of Ni or Cu and the outer layer is made of a Sn-based film satisfies general necessary characteristics and is widely used because it is economical.
As the Sn-based film, a glossy film, a dull film, or a reflowed film that has been remelted and solidified is suitable. Each of the Sn, Sn-Cu, Sn-Ag, Sn-Bi, and Sn-Zn systems (metal, Alloys, eutectoids, compounds) are used. Other than Sn-Bi, a composition near the eutectic with a low melting point is easy to use. The reflow coating is of high quality without worrying about the occurrence of whiskers that cause short circuits.

In particular, Sn, Sn—Cu, and Sn—Ag alloys are excellent in heat resistance.
The Sn-Cu-based and Sn-Ag-based coatings can be provided by forming a thin Cu layer or Ag layer on the Sn coating and forming an alloy upon melting in addition to forming an alloy coating.

The metal layer is generally provided by a wet method. The metal layer at a location other than the resin film is provided after the resin film is formed.
As the wet method, there are an immersion substitution treatment method, an electroless plating method, an electrodeposition method, and the like. Among these, the electrodeposition method is excellent in terms of uniformity of thickness of the metal layer, thickness controllability, bath stability, and the like. Total cost is also cheap.

The electrodeposition method is carried out by constant current electrodeposition using a commercially available bath or a known plating solution, using the metal substrate as a cathode and holding the plating solution at an appropriate relative speed between a soluble or insoluble anode. .
In order to partially provide the metal layer, a method of masking an unnecessary portion, a method of supplying a plating solution in a spot manner only to a necessary portion, or the like can be applied.

In the present invention, the metal layer may be provided only at a necessary location such as a location to be soldered and the metal substrate may be exposed at other locations. Thereafter, from the viewpoint of preventing whiskers, the film may be heated to the melting point or higher to form a remelted solidified reflow coating.

In the third embodiment of the present invention, the metal substrate or the metal layer is ground-treated.
FIG. 5 is an enlarged cross-sectional view of a metal material showing a third embodiment of the present invention.
The metal substrate 1 is subjected to base treatment of organic and inorganic bonds including coupling treatment such as silane coupling treatment and titanate coupling treatment. The resin film 2 is provided, and the Ni layer 3 and the Sn layer 4 are provided in this order on the metal substrate 2 other than the portion where the heat resistant resin film 2 is provided. In this metal material, since the metal substrate 1 is subjected to, for example, silane coupling treatment, the adhesion between the metal substrate 1 and the heat-resistant resin film 2 is improved.

For example, the silane coupling treatment is generally performed by immersing a metal substrate in an aqueous solution in which a silane coupling agent is dissolved. The silane coupling agent is selected from commercially available heat-resistant resin films and those suitable for adhesion of the resin films. In particular, an epoxy-based silane coupling agent is recommended.

It is also possible to provide a heat sink such as a copper material at a place where the heat resistant resin film 2 is not provided on the metal base material of the present invention, thereby significantly improving the heat dissipation. In particular, with the materials shown in FIGS. 3 to 5, the heat sink can be easily joined by soldering.

Although this invention is not restricted to embodiment shown above, in this invention, it is preferable that the height from the metal base material surface to the resin film surface is 60 micrometers or less, and 2 micrometers or more and 30 micrometers or less are more preferable. If this thickness is too thick, it is unsuitable for low-profile parts, and the part formation accuracy is reduced.

In the present invention, a ductile material that can be punched or drawn, or a metal material that has a spring property is used for the metal substrate. Specifically, Cu-based materials such as white (Cu-Ni-based alloy) and phosphor bronze (Cu-Sn-P-based alloy), and Fe-based materials such as 42 alloy (Fe-Ni-based alloy) and stainless steel are listed. It is done. Of these, phosphor bronze is preferable.
The electrical conductivity of the metal substrate is preferably 5% IACS or more, more preferably 10% IACS or more from the viewpoint of electromagnetic shielding properties. The relative permeability is preferably 1 or more. The thickness of the metal substrate is preferably 0.01 to 0.5 mm, and more preferably 0.05 to 0.2 mm.
The metal base material can be manufactured, for example, by melting and casting a predetermined metal material, and sequentially obtaining the ingot obtained by hot rolling, cold rolling, homogenization treatment, and degreasing in the usual manner. .
Moreover, in this invention, although a metal material refers to the metal of various shapes, it points out mainly a metal plate or a metal strip among them.

“Electrical and electronic components” in which the metal material of the present invention is used are not limited thereto, and examples include a housing, a case, a cover, a cap, an insulating spring, and the like. A backed housing and a connector shield housing are more preferable. For example, when forming a housing, the metal material of the present invention is preferably formed with the heat-resistant resin film-forming surface of the metal substrate facing inward.

In addition, as a component that preferably incorporates an electric / electronic component in which the metal material of the present invention is used, it is not limited thereto. For example, a ceramic oscillator mounted on a printed circuit board such as a portable device, a crystal oscillator, Individual components such as voltage-controlled oscillators, SAW filters, diplexers, couplers, baluns, LPFs, BPFs, dielectric duplexers, etc. and various module components incorporating these individual elements (antenna switch modules, front end modules, RF integrated modules) , images sensor module, a tuner module, etc.) and the detection switch, components such as sockets and a liquid crystal driver (LCD) and a keyboard, a printed circuit board side terminal connector, such as a motherboard, or FPC side of connector such as cables and connectors, Such as data and the IC card of the case, and the like.

In addition, the electric and electronic parts using the metal material of the present invention are not limited thereto. For example, electric and electronic devices such as a mobile phone, a portable information terminal, a personal computer, a digital camera, a digital video, and a game machine, or It can be used for electrical components of electrical and electronic equipment mounted on automobiles.

Incidentally, many because electrical electronic component mounted with the high-frequency element inwardly, an insulating and low profile needs, that precisely partially formed shape. For example, an example of a manufacturing method for forming a resin film in a stripe shape with high accuracy is shown below.

The metal base material is supplied while flowing in the longitudinal direction along one end of the base material width while being fixed in the width direction. The liquid resin coating that is the precursor of the resin is supplied in a substantially vertical direction with respect to the surface of the metal substrate from the discharge port of the coating apparatus.

The position of the discharge port is adjusted in advance so that the liquid resin coating is supplied to a predetermined location on the metal substrate, and the discharge port is set to face the surface of the metal substrate. The liquid resin paint is continuously supplied under a predetermined coating condition to a predetermined location on the continuously supplied metal base material for coating. Thereafter, the coated metal material is continuously passed through a superheated furnace, the resin is reactively cured and baked while volatilizing the solvent, and a striped resin film is formed.

The resin film has a width smaller than the width of the metal substrate, and the cross-sectional shape is roughly rectangular, trapezoidal, inverted trapezoidal, etc., and it hangs diagonally at both ends, or the upper ends of both ends protrude partially on the corners. There is also a case. It is desirable to use a discharge port that is similar in shape to the width cross-sectional shape of the resin film.

The coating conditions are the supply pressure and supply distance of the liquid resin paint (the gap distance between the paint discharge port and the surface of the metal substrate). The coating conditions are the dimensions of the resin film to be formed and the resin liquid used. Although depending on the properties of the paint, the supply pressure is about 3 to 50 kg / cm 2 and the supply distance is about 10 to 200 μm.

Hereinafter, the present invention will be described in detail with reference to examples.
JIS alloy C5210R (phosphor bronze, manufactured by Furukawa Electric), C7701R (Yohaku, manufactured by Mitsubishi Electric Metecs), and SUS304-CPS (stainless steel, manufactured by Nisshin Steel Co., Ltd.) having a thickness of 0.1 mm and a width of 15 mm is a metal base. A material was used. Each of the strips was subjected to electrolytic degreasing, pickling treatment, water washing and drying in this order.

Next, a resin film having an elongation percentage of 20% or more and a molecular weight of 15,000 or more is provided by the following method at a location where insulation of each strip after drying is required. 1 to 10 were prepared, and samples each having a width of 10 mm were collected. A 90 ° bending test with bending radii of 0.15 mm and 0.1 mm was conducted with a hand press tester at punch tip radii of 0.15 mm and 0.1 mm and a die clearance of 0.1 mm. After observing and evaluating this, these samples were further crushed by a press machine at ^2.5 N / mm ² and further bent 180 ° to evaluate the workability of the test material and the resin film. The case where the resin film of the bent portion is not broken is indicated as ◯, the case where a crack is present but the fracture is not broken and the insulation is maintained is Δ, and the case where the resin film is broken or broken is indicated as x. did. The composition of the sample and the test results are shown in Table 1 (No. 1 to 18). The elongation rate of the resin film was obtained by repeatedly applying and baking the resin on a 1 mm diameter copper wire to reduce the film thickness from 30 μm, and then removing and cutting the resin film with a thickness of 30 μm. As a material, a tensile test was performed until the material was broken by a tensile tester, and the elongation was measured.

Polyimide solution or precursor solution (made by Arakawa Chemical Co., Ltd.), n-methyl 2-pyrrolidone having various elongation and molecular weight as a solvent, polyamideimide solution or precursor solution (made by Tohoku Paint Co., Ltd.), Each varnish (liquid resin paint) of epoxy resin solution (made by Dainippon Paint Co., Ltd.) using methyl ethyl ketone as a solvent, and polyester or precursor solution (made by Tohoku Paint Co., Ltd.) using cresol as a solvent The material is coated in a stripe shape having a thickness of 3 μm or more and a width of 7 mm at the center in the width direction, and then subjected to predetermined heat treatment (polyimide-based solution, polyamide-imide-based solution and polyester-based solution at 300 ° C. for 1 minute, and epoxy-based solution at 250 ° C. 2 minutes) and cured or polymerized with solvent drying to provide a resin film. The thickness of the resin film was changed.

As a comparative example, a test material was prepared and tested and evaluated in the same manner as in the example except that a resin film having an elongation of less than 20% or a resin film having a molecular weight of less than 15,000 was present. Table 1 (Nos. 19 to 23) shows the test results and the specimen composition.

As is clear from Table 1, the materials of the examples (Nos. 1 to 1 2 ) of the examples of the present invention were excellent in workability in any resin film. However, it is No. that can endure even the most severe processing without cracks. 4-9 , 11-12 were all materials in which a resin film having an elongation of 30% or more or a molecular weight exceeding 20,000 was formed.

On the other hand, since the materials of the comparative examples (No. 19 to 23) are materials having a low elongation rate and molecular weight, the workability is inferior to those of the examples. It cannot be handled.

It is sectional drawing of the width direction of the metal material for electrical and electronic components which shows the 1st embodiment of this invention. It is sectional drawing of the width direction of the metal material for electrical and electronic components which shows the 2nd embodiment of this invention. It is sectional drawing of the width direction of the other metal material for electric and electronic components which shows the 2nd embodiment of this invention. It is sectional drawing of the width direction of the other metal material for electric and electronic components which shows the 2nd embodiment of this invention. It is sectional drawing of the width direction of the metal material for electrical and electronic components which shows the 3rd embodiment of this invention. It is sectional drawing of the width direction of the other metal material for electric and electronic components which shows the 1st embodiment of this invention. It is sectional drawing of the width direction of the other metal material for electric and electronic components which shows the 1st embodiment of this invention. It is a figure of the resin film formation surface of the metal material for electrical and electronic components which shows the 1st embodiment of this invention. It is sectional drawing of the width direction of the other metal material for electric and electronic components which shows the 1st embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal base material 2 Resin film 3 Ni layer 4 Sn layer 5 Ground treatment layer

Claims (2)

A resin film having a thickness of 2 μm or more and less than 15 μm is partially formed on at least a part of the metal substrate, and the resin film is coated with a liquid resin paint or a resin varnish on the metal substrate, and is reactively cured. a resin film obtained by a imidization ratio of 20% or more of the polyamide-imide resin, and a number average molecular weight of 15,000 or more and Ri polymer resin film der elongation rate has more than 20% to break, bend After bending 90 ° with a radius of 0.15 mm, when the bending part is further crushed by a press machine at ^2.5 N / mm ² and 180 ° bending is performed, the resin film at the bending part does not break. Features electrical and electronic component materials. An electrical / electronic component using the electrical / electronic component material according to claim 1.

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