JP2006086513A - Material of electric and electronic component case or shield case and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a material of an electric and electronic component case or a shield case, which is suitable for a short-height cabinet of a connector, and in which whiskers do not occur after it is left to stand for a long period of time. <P>SOLUTION: The material of the electric and electronic component case or the shield case, has a resin film 2 deposited at a part on a metallic base material 1, and has an Sn or Sn alloy plating layer 3 re-melted and solidified on at least a part on a metallic base material other than the resin film. The material of the electric and electronic component case or the shield case, has at least one metallic layer on the metallic base material, and the resin film is prepared directly on the metallic base material, or prepared through at least one metallic layer. In the material of the electric and electronic component case or the shield case, the metallic base material or the metallic layer is subjected to surface treatment. In a metallic material for the electric and electronic component, the height from the surface of the metallic base material to the surface of the resin film is at most 60 μm. The electric and electronic component case or a part of the shield case is obtained by using the metallic material. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is connected to, for example, a housing, a case, a cover, a cap, a printed circuit board, and a cable of a low-profile electrical / electronic component embedded in an electronic / electronic device, particularly a portable device. The present invention relates to materials suitable for connector parts and shield cases.

  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 parts such as an antenna switch module, a front end module, an RF integrated module, a Bluetooth module, an image sensor module, a tuner module, a wireless LAN application, a detection switch, a microphone, etc. It is used by putting it in a metal casing or covering it with a cover for electromagnetic shielding, but the casing and the like are required to be thin and low in height while the portability of electric and electronic equipment is progressing. Its height is module parts Is 5mm or less, is being rushed to 2mm before and after the split 1mm than individual parts. Furthermore, since the devices are becoming lighter, thinner, and more sophisticated due to digital and higher frequencies, the same tendency is also increasing in liquid crystal drivers (LCDs), keyboards, motherboards, and the like. In particular, the evolution of the interface with the LCD driver is very fast, and new products are being developed as the generation of mobile devices is updated. The terminal connector on the printed circuit board side and the connector on the FPC cable side are required to have electromagnetic shielding properties for the purpose of preventing communication noise and static electricity, and are used by covering them with conductive metal cases, caps, and covers. However, devices are becoming smaller and thinner, and connector connectors and card connectors and other 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, a 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, the main use equipment such as electrical and electronic parts and connectors will shift from the conventional PC level dimensions to mobile devices such as mobile phones. The metal housing, etc., has a smaller internal volume as the height is lowered, and the space between the inner surface of the component case and the connector terminal and the exterior shield part such as the case, cover, cap, and housing (case with cover) A problem has arisen that insulation cannot be secured sufficiently. Thus, although the method disclosed in Patent Document 1 can be used, there has been a problem that the manufacturing method is complicated due to high cost.
The present invention solves the problem that a conventional shield case part formed from a metal material for a case cannot sufficiently secure insulation from the case of an electrical / electronic part or connector part, and further improves the parts assembly and heat resistance mounting. Provide materials that can be secured. In the case of connector products, there is a possibility that the period for inventory storage etc. may be long until it is actually used, but there is no need to worry about causing whiskers during that period, and there is no need to connect to printed circuit boards or FPC cables. An object of the present invention is to provide a case material that is suitable for a case housing such as a shielded connector or a thin card connector that is turned over, and that can sufficiently ensure insulation, heat dissipation, and heat resistance from the connector itself.

As a result of intensive studies on the insulation properties of electrical and electronic component materials, the present inventors can sufficiently ensure insulation with the built-in connector itself by providing a resin film on the metal substrate where insulation is required. I found. Furthermore, in order to sufficiently secure heat-resistant mounting by solder bonding, it is necessary to form a surface treatment layer having excellent solder wettability on portions other than the resin.
In addition, re-melting and solidification (reflow) of the Sn alloy plating layer by reflow treatment has led to prevention of whisker generation.

That is, the present invention
(1) Having a resin film on a part of the metal substrate, and having a plated layer of Sn or Sn alloy on at least a part of the metal substrate at a portion where the resin film is not provided, and the Sn or Sn A material for an electrical / electronic component case or shield case, wherein the alloy plating layer is provided by remelting and solidifying;
(2) The material of the electrical / electronic component case or shield case, wherein the resin film provided on the metal substrate is a heat-resistant resin,
(3) It has at least one metal layer on the metal substrate, and the resin film is provided on the metal substrate directly or via the metal layer. Material for electrical / electronic parts case or shield case,
(4) The electrical and electronic component case or shield according to any one of (1) to (3), wherein a surface treatment layer is provided on the surface of the metal substrate or the surface of the metal layer. Case material,
(5) The material of the electric / electronic component case or shield case according to any one of (1) to (4), wherein the height from the surface of the metal base to the surface of the resin film is 60 μm or less .
(6) An electric / electronic component case or a shield case, wherein the shield case material according to any one of (1) to (5) is used;
(7) Any one of a cleaned metal base, a metal layer provided on the metal base, a base treatment layer provided on the metal base, and a base treatment layer provided on the metal layer An electrical and electronic device characterized in that a resin film is formed on a part of the surface, and then a Sn or Sn alloy plating layer is provided on any of the surfaces not provided with the resin film, followed by a reflow treatment. Manufacturing method of material of parts case or shield case,
Is to provide.

Case materials such as low-profile electrical and electronic parts and thin connectors of the present invention,
First, since the resin film is provided on at least a part of the metal substrate, for example, when the resin film is used in a casing with the resin film inside, sufficient insulation between the connector itself can be ensured. . Therefore, it is possible to reduce the height of the connector housing, which is useful for reducing the thickness of portable devices and the like.
Secondly, when the resin film is provided only at a place where insulation is required, the metal base is exposed at a place where the resin film is not provided, and the heat dissipation is maintained at a high level.
Thirdly, by providing a reflow Sn or Sn alloy metal layer at the exposed portion of the metal base material, it is possible to improve solder jointability (solder mountability), heat resistance, corrosion resistance, etc., and Sn or Sn formed by plating. Since the alloy layer is a reflow metal layer in which internal stress is released by remelting and solidifying by heating, there is no risk of whisker generation which becomes a problem in the Sn or Sn alloy layer, and it can be used with confidence.
Fourthly, by using a heat-resistant resin as the resin, it is possible to prevent deterioration of characteristics such as discoloration, adhesion, and insulation properties of the resin during the reflow heat treatment.
Fifth, when the metal substrate is formed with a metal layer, or when the metal substrate or the metal layer is ground-treated, the adhesion of the resin film provided thereon is improved.
Sixth, when the height from the surface of the metal substrate to the surface of the resin film is 60 μm or less, it can be suitably used as a low-profile casing.
By these things, there is an industrially remarkable effect.

  Hereinafter, preferred embodiments of the metal material for electrical and electronic parts of the present invention will be described in detail with reference to the drawings. The present invention is not limited to these embodiments.

  A first embodiment of a shield case according to the present invention has a resin film on a part of a metal substrate and is remelted and solidified on at least a part of the metal substrate other than the resin film. The plating layer is provided.

FIG. 1 is an enlarged cross-sectional view showing a structure according to the first embodiment of the present invention.
A heat-resistant resin film 2 is provided at one place on the metal substrate 1 that requires insulation, and the reflow Sn or Sn alloy plating layer 3 is formed on the metal substrate other than the place where the heat-resistant resin film 2 is provided. Is provided.

FIG. 2 is an enlarged cross-sectional view showing another embodiment according to the first embodiment of the present invention.
The heat resistant resin film 2 is provided at two places on the metal substrate 1 that require insulation, and the reflow Sn or Sn alloy plating layer 3 is formed on the metal substrate other than the place where the heat resistant resin film 2 is provided. Is provided.

  The metal material shown in FIGS. 1 and 2 has an effect of preventing the occurrence of whiskers because the reflow Sn or Sn alloy plating layer 3 is provided on the metal substrate 1 other than the portion where the heat resistant resin film 2 is provided. .

The part having the resin film is preferably a part requiring insulation. In one preferable embodiment, the resin film is provided only at a location requiring insulation. A place that requires insulation is a place where it is necessary to prevent electrical short-circuit between the metal material that is the part case and the connector terminal part or element inside the part or the electrical wiring circuit by insulating the part. means. The resin film is preferably a heat resistant resin film. When the component is solder-mounted or when the Sn or Sn alloy plating layer of the present invention is reflow-heated, it is possible to prevent discoloration of the resin and deterioration of the characteristics.
If the thickness of the heat-resistant resin film is too thin, sufficient insulation cannot be obtained, and pinholes are likely to be generated. Therefore, the thickness is preferably 2 μm or more, and more preferably 3 μm or more. On the other hand, if it is too thick, the moldability to a housing or the like is lowered, so that it is preferably 50 μm or less, more preferably less than 15 μm.
In addition, the insulating property of the heat resistant resin film is preferably 10 ¹⁰ Ωcm or more as a volume resistivity.
More preferably, it is 0 ¹⁴ Ωcm or more.

In the method of providing a heat resistant resin film on a metal substrate, (a) a heat resistant resin film with an adhesive is arranged at a location requiring insulation on the metal substrate, and the adhesive is melted by an induction heating roll. Next, a method of heat-treating and heat-reacting and bonding, (b) A method of applying a varnish in which a resin or a resin precursor is dissolved in a solvent and then heat-treating to volatilize the solvent and reaction-hardening and bonding the resin, etc. Is mentioned.
The method (b) is recommended in that the heat-resistant resin film can be positioned with high accuracy on the metal substrate. Even with the method (a), high accuracy can be achieved depending on the employed construction method and apparatus. For example, a method that applies roll coating equipment for offset (planographic) printing or gravure (intaglio) printing on the painted part, or a method that applies photosensitive heat-resistant resin, pattern formation by ultraviolet rays or electron beams, and resin curing technology In addition, depending on the resin film formation accuracy level from the application of fine pattern formation technology to the resin film (eg, photographic etching technology and screen printing technology used for printed circuit boards) by exposure phenomenon etching dissolution in circuit boards Manufacturing methods can be adopted. The tolerance of the position where the heat-resistant resin film is provided on the metal substrate is preferably ± 0.15 mm, more preferably ± 0.10 mm, and even more preferably ± 0. 05 mm.
In addition, the method of providing a resin film is not limited to said (a) and (b), It can carry out by the method suitable for resin.

  For the resin forming the resin film, for example, polyimide, polyamideimide, polyamide, epoxy, polyester (including polyethylene terephthalate, polyethylene naphthalate, etc.), polysulfone, and polycarbonate resins are used. . As the heat-resistant resin, for example, those having a glass transition temperature of 200 ° C. or higher, desirably 250 ° C. or higher are suitable, or a resin having a UL heat-resistant life temperature of US UL standard of 180 ° C. or higher, preferably 220 ° C. or higher. Resin is used well. Since the melting point of Sn is 232 ° C., a higher temperature atmosphere is required as the heating temperature for melting it, and therefore, a resin having a thermal decomposition starting temperature of at least 350 ° C. or higher is desirable. That is, a polyimide-based or polyamide-imide-based resin is preferable, and an epoxy-based resin conforms to this.

  Moreover, when providing a heat resistant resin film | membrane on a metal substrate etc. using an adhesive agent, resin, such as a polyimide type, an epoxy type, an acryl type, a silicon type, is used for an adhesive agent. These resins have heat resistance against heating processes such as solder bonding and reflow solder mounting. In applications where the heating conditions are not severe, it is also possible to use a resin having a low heat resistance other than the resin (for example, a polyamide-based, polyester-based, or polycarbonate-based resin).

On the other hand, a reflow Sn or Sn alloy plating layer remelted and solidified is provided on at least a part of the metal substrate other than the resin film.

For example, in the case of solder mounting, the thickness of the Sn-based plating layer is desirably 1 μm or more, which maintains good solder wettability and enables fusion bonding such as reflow solder mounting. The upper limit is about 20 μm, and the effect is saturated even if the thickness is increased further. In other applications, the thickness is preferably in the range of 0.1 μm or more and 10 μm or less from the viewpoints of corrosion resistance and resin adhesion.

In the case of a connector application, since a glossy appearance is preferred, it is necessary to form a reflow layer that has been heated, remelted and solidified together with the purpose of preventing whisker in the Sn-based film. In the case of a bright plating layer, whiskers are considerably suppressed by Ni undercoating or the like, but the risk of occurrence due to the aging environment remains. Therefore, after forming the matte plating layer of each system (metal, alloy, eutectoid, compound) of Sn, Sn-Cu, Sn-Ag, Sn-Bi, Sn-Zn, it is heated and remelted and solidified. Used as almost no reflow Sn-based plating layer. Other than Sn-Bi, a composition near the eutectic with a low melting point is easy to use.
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.

As a method for reflow treatment of Sn or Sn alloy layer and heating and remelting and solidifying, a method of exposing the material of the present invention after film formation to a heating atmosphere and conditions generally determined by the heating method and temperature and the exposure time is used. The melting point of the Sn-based film is around 200 ° C. However, in order to heat and melt continuously in a short time, the heating of 300 ° C. or higher is easy to transfer heat to the film or the metal substrate, or the heating furnace with a built-in fan. In addition, an induction heating method using a high frequency of a metal base material that can easily prevent deterioration and discoloration of the resin can also be used. In addition, the formation of the Sn-based alloy plating layer is performed after the resin film is formed by using a wet method which is a metal layer forming method described later.

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

FIG. 3 is an enlarged cross-sectional view showing the structure according to the second embodiment of the present invention.
A heat-resistant resin film 2 is provided at least at one place on the metal substrate 1 that requires insulation, and the Ni layer 4 and reflow Sn or the like on the metal substrate 1 other than the place where the heat-resistant resin film 2 is provided. The Sn alloy plating layer 3 is provided in this order.

FIG. 4 is an enlarged sectional view showing another embodiment according to the second embodiment of the present invention.
The Ni layer 4 is provided on the metal substrate 1, the heat-resistant resin film 2 is provided at two places on which insulation is required, and the Ni layer other than the place where the heat-resistant resin film 2 is provided. A reflow Sn or Sn alloy plating layer 3 is provided on 4.

In the embodiment shown in FIGS. 3 and 4, since the reflow Sn or Sn alloy plating layer 3 is provided on the metal substrate 1 other than the place where the heat resistant resin film 2 is provided, solder bonding or reflow solder mounting is performed. Etc. can be easily performed. Further, since the diffusion of the metal base material 1 component is blocked by the Ni layer 4, discoloration of the reflow Sn or Sn alloy plating layer 3 is prevented. In addition, since the heat resistant resin film 2 is provided on the Ni layer 4 in the case shown in FIG. 4, the effect of improving the adhesion with the resin film can be obtained.
Also, as shown in FIGS. 3 and 4, the metal substrate 1 provided with a metal layer between the metal substrate and the surface layer is well protected, and the metal substrate 1 has heat resistance, oxidation resistance, and corrosion resistance. Etc. improve. An underlayer provided with a Ni layer or a Cu layer is recommended because the compounding of the Sn layer is sufficiently suppressed, and heat resistance and whisker resistance are highly maintained. It is more effective to provide two or more base metal layers, but one base metal layer is appropriate in terms of cost performance.

The metal layer may be provided in a single layer or multiple layers. The case of a single layer, that is, the case of an Sn-based plating layer has been described in the first embodiment. In the case of multiple layers, that is, when the Sn-based plating layer is provided on the outermost layer via a base metal layer, it is more preferable that it is two layers consisting of an outer Sn-based plating layer and a base metal layer from the viewpoint of cost performance, The thickness is preferably in the range of 0.1 μm or more and 10 μm or less. The thickness of each layer constituting the multilayer is preferably 0.1 μm or more and 10 μm or less.

The material of the base metal layer is preferably Ni or Cu. When there are two or more underlayers, Cu, Ag, and Pd systems are preferably used for the layer in contact with the resin film and the Sn-based plating layer. Whisker generation is prevented by forming an Sn or Sn alloy layer that has been remelted and solidified by heating after the formation of Sn-based metal plating on the underlying metal 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 layer is one or more Ni- or Cu-based coatings and the outermost layer is a Sn-based coating satisfies general required characteristics and is widely used because it is economical.

The metal layer is generally provided by a wet method.
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 performed 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 plating layer, a method of masking unnecessary portions, a method of supplying a plating solution in a spot manner only to necessary portions, or the like can be applied. The portions other than the plating may be left in a state where the metal substrate is exposed.

  In the third embodiment of the present invention, a Sn or Sn alloy metal plating layer remelted and solidified with a resin film is provided on a metal substrate or metal layer that has been subjected to a base treatment.

FIG. 5 is an enlarged cross-sectional view showing the structure according to the third embodiment of the present invention.
The metal substrate 1 is subjected to a base treatment of organic and inorganic bonds including a coupling treatment such as a silane coupling treatment or a titanate coupling treatment, and heat resistance is applied to one place requiring insulation on the base treatment layer 5. The resin film 2 is provided, and the Ni layer 4 and the reflow Sn or Sn alloy plating layer 3 are provided in this order on the base treatment layer 5 other than the place where the heat resistant resin film 2 is provided. In this case, since the metal substrate 1 is subjected to silane coupling treatment, the adhesion between the metal substrate 1 and the heat-resistant resin film 2 is improved.

It is also possible to provide a heat sink such as a copper material at a location where the heat-resistant resin film 2 of the shield case material of the present invention is not provided, 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.
Moreover, h shows the height from the metal base material surface to the resin film surface in FIGS.

In the present invention, it is also preferred that the metal substrate or the metal layer is subjected to organic and inorganic bond base treatment including coupling treatment such as silane coupling treatment and titanate coupling treatment. When the metal substrate or the metal layer is subjected to, for example, silane coupling treatment, the adhesion between the metal substrate or the metal layer and the heat resistant resin film 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. As the silane coupling agent, a heat-resistant resin film to be used or a material suitable for adhesion of the resin film is selected from commercially available products. In particular, an epoxy-based silane coupling agent is recommended.

FIG. 6 is a plan view showing another embodiment according to the present invention.
A heat-resistant resin film 2 is provided in stripes on the metal substrate 1 where insulation is required. The reflow Sn or Sn alloy plating layer 3 or the Ni layer 4 and the reflow Sn or Sn alloy plating layer 3 may be provided in this order on a metal substrate other than the place where the heat resistant resin film 2 is provided. In addition, the metal substrate 1 is provided with a heat-resistant resin film 2 at one place that requires insulation on the organic and inorganic bond base treatment layer 5 including coupling treatment such as silane coupling treatment and titanate coupling treatment, The Ni layer 4 and the reflow Sn or Sn alloy plating layer 3 may be provided in this order on the base treatment layer 5 other than the place where the heat resistant resin film 2 is provided.

FIG. 7 is a plan view showing another embodiment of the present invention.
A heat-resistant resin film 2 is provided in a spot shape on the metal substrate 1 where insulation is required. Others are the same as the embodiment shown in FIG.

In the present invention described above, as the metal base material, a material having ductility that can be punched, bent, drawn, or the like, or a material having a spring property is used. 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. In particular, phosphor bronze is preferred.
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 substrate can be produced, for example, by melting and casting a predetermined metal material, and sequentially obtaining the ingot obtained by a hot rolling process, a cold rolling process, a homogenization process, and a degreasing process in a conventional manner. it can.
Although the said metal base material points out the metal of various shapes, it points out mainly a metal plate or a metal strip among them.

Further, the case of electric / electronic parts and connectors and the shield case according to the present invention are not limited thereto, but examples include a case, a case, a cover, a cap, etc. More preferred is a cap. 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.

  Furthermore, the connector in which the material of the present invention is used is not limited thereto. For example, in a personal computer, AV device, game machine, portable device, etc., for example, a printed circuit board terminal such as an LCD, a keyboard, or a motherboard. Or a connector connected to an FPC cable or a thin card connector.

In addition, the connector parts using the material of the present invention are not limited thereto. For example, electronic telecommunications equipment such as a personal computer, a game machine, a mobile phone, a portable information terminal, a notebook computer, a digital camera, and a digital video. Can be used for connecting terminals and cables of rigid substrates such as LCDs, keyboards and motherboards, flexible substrates, and wireless or contact type thin cards.

  The height from the metal substrate surface to the resin film surface is preferably 60 μm or less, more preferably 2 μm or more and 30 μm or less. If this thickness is too thick, it is unsuitable for low-profile parts, and the part formation accuracy is reduced.

Hereinafter, the present invention will be described in detail with reference to examples.
Example 1
JIS C5210R (phosphor bronze, manufactured by Furukawa Electric), C7701R (Yakuhoku, manufactured by Mitsubishi Electric Metecs), and SUS304-CSP (stainless steel, manufactured by Nippon Metals Co., Ltd.) with a thickness of 0.1 mm and a width of 20 mm are used as the original metal strip. It was. Each of the strips was subjected to electrolytic degreasing, pickling treatment, water washing and drying in this order. Some strips were subjected to a ground treatment using a silane coupling solution or a triazine solution before the drying step.

Next, a heat-resistant resin film having a thickness of 3 μm or more is provided by a method of either (a) or (b) below at a place where insulation of each strip after drying is required. 1-21 were created.
(A) One side of a strip (metal substrate) of each varnish of a polyimide solution or precursor solution using n-methyl 2-pyrrolidone as a solvent, a polyamideimide solution or precursor solution, or an epoxy resin solution using methyl ethyl ketone as a solvent The film was coated in a stripe shape (width 10 mm) at the center in the width direction, and then subjected to heat treatment to evaporate the solvent, and the resin was cured or polymerized to provide a heat resistant resin film.
(B) A heat-resistant polyimide resin film (thickness 12.5 μm) pre-applied with an adhesive (thickness 15 μm) is slit to a width of 3 mm, and this is spaced at intervals of 2 mm at the center in the width direction on one side of the strip (metal substrate). Two of them were pasted and heat-pressed between two induction heating rolls, and the adhesive was melt-cured and joined by two-stage heat treatment.

Using a strip partially provided with the heat-resistant resin film, the peel strength of the heat-resistant resin film from the metal substrate was examined with a Tensilon tester.

  A metal layer was electroplated using a commercially available or publicly known electroplating bath on the surface of the strip where the heat-resistant resin film was not formed to produce a strip material. Next, the material on which the Sn-based metal layer was formed was a glossy Sn-based metal layer reflowed by heat treatment. After these samples were put in a thermostat at 50 ° C. for 1500 hours, the surface was observed with a microscope to determine whether whiskers or the like were generated.

  Next, the strip material was cut into short pieces and punched into a shape approximately 15 mm square or 5 mm square, and this was drawn into a cover.

  The cover is used to cover the parts of the test substrate (5 chips, 2 mm in height), and after 100 minutes of direct current is applied between the resin and the metal substrate for 1 minute, the insulation resistance when 1 minute is discharged. Examined. Next, the temperature inside the cover (in-part temperature) after the test substrate was continuously operated for 5 hours was measured to examine the heat dissipation of the cover. Furthermore, after the cover was floated in a solder bath at 280 ° C. for 3 minutes, the appearance was observed to examine the reflow heat resistance.

  In this example, regarding the resin film, the forming method, the thickness and the type of the film, and when the resin film is formed by the above method (b), the type of the resin used for the adhesive, and the Sn plating layer is plated. Regarding the thickness and material of the layer, etc., the type of the base plating layer and the presence or absence of the base treatment using a silane coupling solution or a triazine solution were investigated. The results of the survey are shown in Tables 1 and 2. 1-No. 21. Tables 1 and 2 also show the composition of the strip material. In Tables 1 and 2, “Coating” in the column of the resin forming method indicates that the coating is provided by the method (a), and “Film” indicates that the coating is provided by the method (b). Further, “Polyimide”, “Epoxy”, “Acrylic”, and “Silicon” in the column of adhesive type in Table 1 indicate the type of resin used for the adhesive in the method (b).

Example 2
Sample No. 1 in Example 1 except that the thickness of the heat resistant resin film was 2 μm. The strip material (sample No. 22) was produced by the same method as in Example 1, and the Sn metal layer was reflowed by heat treatment. The same test as in Example 1 was performed. Table 2 shows the test results and the composition of the strip material.

Example 3
Sample No. 1 of Example 1 was used except that a heat-resistant resin film was provided on the entire surface of one side of the metal substrate by the method (a) in Example 1 (single-sided coating), and the thickness of the heat-resistant resin film was 7 μm. A strip material (sample No. 23) was prepared in the same manner as in No. 2, and the Sn metal layer was reflowed by heat treatment. In addition, a heat-resistant resin film was provided on the entire surface of one side of the metal substrate by the method (a) in Example 1 (single-sided coating), the thickness of the heat-resistant resin film was 6 μm, and the thickness of the base plating was 0.1 μm. Except for the sample No. in Example 1. A strip material (Sample No. 24) was prepared in the same manner as in Example 9. These were subjected to the same test as in Example 1. The test results and the composition of the strip material are shown in Table 2.

Comparative Example As a comparative example, a material (sample No. 25 and No. 26) in which a metal layer was simply electroplated on the surface of phosphor bronze and white strips was manufactured, and the same test as in Example 1 was performed. The Sn metal layer was left as a plating layer without being heated and reflowed. Table 2 shows the test results and the composition of the strip material.

  In the examples, the height h (see FIGS. 1 to 5) from the surface of the base material to the surface of the heat resistant resin film was 60 μm or less.

＊：リフロー耐熱性評価について、◎良好、○樹脂若干変色あるが耐熱性は良好、△はんだ接合可能な程度。

*: Regarding reflow heat resistance evaluation, ◎ Good, ○ Resin slightly discolored, but heat resistance is good, △ Solderable.

As is apparent from Tables 1 and 2, Example Nos. Of the present invention prepared in Examples 1 to 3 were used. Any of the materials 1 to 24 has high peeling strength and insulation resistance of the resin film, the temperature inside the cover is lower than the upper limit temperature for use of the component, 70 ° C., excellent reflow heat resistance, and no risk of whisker generation. It was possible to ensure mountability.
No. 3 and 4, and When comparing 23 and 24, it can be seen that if the silane coupling treatment is performed before the resin is formed, the peel strength is improved.
No. 2 prepared in Example 2. Since the material No. 22 had a relatively thin heat-resistant resin film, the peel strength and insulation resistance slightly decreased. Further, although discoloration was observed in the resin, it was in a level where there was no practical problem.
No. 1 prepared in Example 3. Since the materials of Nos. 23 and 24 were provided with a heat-resistant resin film on one side of the metal substrate, the internal temperature of the cover was increased, but the functions were not problematic and were practical.

On the other hand, the materials of Comparative Examples (No. 25 and 26) are inferior in insulation because they are not provided with a heat-resistant resin film, and none of them can sufficiently cope with the reduction in height, and after the constant temperature acceleration test, Whiskers and granular protrusions at the previous stage were observed from the Sn layer of the outer metal layer, and it was found that there is a possibility of causing defects such as a short circuit when using the parts.

It is an expanded sectional view showing a thing concerning a 1st embodiment of the present invention. It is an expanded sectional view showing other modes concerning a 1st embodiment of the present invention. It is an expanded sectional view showing a thing concerning a 2nd embodiment of the present invention. It is an expanded sectional view showing other modes concerning a 2nd embodiment of the present invention. It is an expanded sectional view showing a thing concerning a 3rd embodiment of the present invention. It is a top view which shows other embodiment of this invention. It is a top view which shows other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal base material 2 Heat resistant resin film 3 Reflow Sn or Sn alloy plating layer 4 Ni layer 5 Ground treatment layer

Claims (7)

  A part of the metal base material has a resin film, and a part of the metal base material where the resin film is not provided has a Sn or Sn alloy plating layer, and the Sn or Sn alloy plating A material for an electric / electronic component case or shield case, wherein the layer is provided by remelting and solidifying.   The material for an electric / electronic component case or shield case according to claim 1, wherein the resin film provided on the metal substrate is a heat-resistant resin.   The metal substrate has at least one metal layer, and the resin film is provided on the metal substrate directly or via the metal layer. Or the material of the electrical-electronic component case or shield case of 2.   The material for an electric / electronic component case or shield case according to any one of claims 1 to 3, wherein a base treatment layer is provided on the surface of the metal base material or the surface of the metal layer. .   The material from the surface of the metal substrate to the surface of the resin film is 60 microns or less, and the material for an electric / electronic component case or shield case according to any one of claims 1 to 4.   An electrical / electronic component case or shield case, wherein the material of the electrical / electronic component case or shield case according to claim 1 is used. One surface of any one of a cleaned metal base, a metal layer provided on the metal base, a base treatment layer provided on the metal base, and a base treatment layer provided on the metal layer A resin film is formed on the part, and then a plating layer of Sn or Sn alloy is provided on any of the surfaces where the resin film is not provided, and then reflow treatment is performed. A method of manufacturing a shield case material.

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