JPWO2013118752A1 - Cover-lay film, light-emitting element mounting substrate, and light source device - Google Patents

Abstract

A cover layer that has high reflectivity in the visible light region, has little decrease in reflectivity under high-temperature heat load environment, and light resistance test environment, and can be used for printed circuit boards for LED mounting. Provide film etc. A resin layer containing a polyorganosiloxane and an inorganic filler, having an average reflectivity at a wavelength of 400 to 800 nm of 85% or more, and a decrease in reflectivity at a wavelength of 450 nm after heat treatment at 260 ° C. for 10 minutes A coverlay film for protecting a conductor circuit of a printed wiring board having a rate of 5% or less.

Description

  The present invention protects the surface of a printed wiring board, in particular, a substrate on which a light emitting element such as an LED is mounted, a cover lay film for protecting a conductor circuit such as a metal wiring, and a light emitting element mounting layer formed by laminating the cover lay film The present invention relates to a substrate and a light source device. More specifically, it has a high reflectivity, and even after passing through a high-temperature heat load environment or a light resistance test environment, a decrease in reflectivity is suppressed, that is, a high reflectivity is maintained, and the phosphor is dispersed. The present invention relates to a coverlay film that can also be used as a dam material when filling resin.

  Chip type LEDs with LEDs mounted directly on the printed circuit board pattern and resin-sealed are advantageous for miniaturization and thinning. Therefore, electronic devices such as numeric keypad lighting for mobile phones and backlights for small liquid crystal displays are available. Widely used in equipment.

  In recent years, the technology for increasing the brightness of LEDs has been remarkably improved, and the brightness of LEDs has been increased. As a result, the amount of heat generated by the LED element itself increases, and the ambient temperature of the LED element may exceed 100 ° C., which increases the thermal load on components such as a printed wiring board. Also, when looking at the manufacturing process of the LED mounting substrate, the LED element has a heating temperature of about 260 to 300 ° C. in the thermosetting process of the sealing resin and the reflow process after joining with lead (Pb) -free solder. The surroundings are exposed to a high temperature heat environment not only during use but also in the manufacturing process.

  White printed wiring boards such as thermosetting resin compositions that have been used in the past, such as thermosetting resin compositions that are coated with a thermosetting solder resist, are used in an environment where a thermal load is applied as described above. , A tendency was observed in which the whiteness decreased and the reflection efficiency decreased due to yellowing of the solder resist and the printed wiring board. Therefore, when developing a substrate for mounting a next-generation high-brightness LED in the future, it is necessary to improve such a decrease in reflection efficiency.

  In addition, for products with a white printed wiring board that is formed by coating a white solder resist, the degree of whiteness, such as yellowing, is also the same as in the heat load environment, even in an environment where ultraviolet rays are irradiated. There was a tendency for the reflectivity to decrease due to a decrease.

  On the other hand, although a substrate made of ceramic is excellent in heat resistance, it has a hard and brittle property, so there is a limit to increase the area and thickness. Therefore, there is a possibility that a substrate made of the ceramic may be difficult to be used as a substrate used in future general lighting applications or display applications. Therefore, there has been a demand for the development of a printed wiring board in which a cover lay film is laminated as a heat-resistant substrate that does not cause discoloration or a decrease in reflectance even under a high temperature heat load and can cope with a large area. .

  Further, in the process of mounting the LED chip on the printed wiring board, the mounting portion is filled with a sealing resin (silicone resin, epoxy resin, or the like) in which a phosphor is dispersed. At this time, a dam material made of a thermosetting resin (for example, a silicone resin or an epoxy resin) is formed so that the sealing resin does not leak to the peripheral portion.

  In the formation of such a dam member, generally, a dam material is generally formed by a dispenser or the like and thermally cured. However, when the resin is heat-cured, the wiring portion may be contaminated and the wire bonding property may be affected, or the white solder resist and the printed wiring board material may be thermally deteriorated, so a dam material is formed. It was a challenge. Furthermore, since the manufacturing cost is high, development of a coverlay film in which a conductor protective layer such as metal wiring and a dam material are integrated, and a printed wiring board formed by laminating such a coverlay film have been demanded.

Regarding the above-described problems, conventionally, for example, 5 to 100 inorganic fillers are used with respect to 100 parts by mass of a resin composition comprising a polyaryl ketone resin having a crystal melting peak temperature of 260 ° C. or higher and an amorphous polyetherimide resin. By using a resin composition containing parts by mass, a coverlay film in which a decrease in reflectance is suppressed even under a high-temperature heat load environment or a light resistance test environment has been proposed (see, for example, Patent Document 1).
This Patent Document 1 shows characteristics suitable for adhesion to the surface of a printed wiring board when heated to a low temperature of 260 ° C. or lower by utilizing the crystallinity of a thermoplastic resin composition, and has a relatively short time. A cover lay film is disclosed that can be bonded together with a heat resistant temperature of 260 ° C. after heat sealing.

JP2009-302110A

  The film described in Patent Document 1 has insufficient initial reflectance and light discoloration resistance. Moreover, there was no description or suggestion about a technology that can be widely applied, such as being usable as a dam material.

  The object of the present invention is a cover lay film that has high reflectivity in the visible light region, high heat resistance, and little reduction in reflectivity under high-temperature heat load environment or light-resistant environment, and can cope with a large area. In particular, it is to provide a cover lay film that can be used for a printed wiring board for LED mounting, and a light emitting element mounting substrate and a light source device formed by laminating the cover lay film.

  As a result of intensive studies by the present inventors in order to further improve the above-mentioned reflectance problem, polyorganosiloxane was used as a thermosetting resin, and a resin composition containing this resin and an inorganic filler was used as a gamma ray or the like. By curing with radiation, not only the average reflectance in the visible light region, specifically in the wavelength range of 400 to 800 nm is high and the reflectance in the wavelength region of 350 to 400 nm in the ultraviolet region is also high, It has been found that the decrease in reflectance can be suppressed even under a load environment or a light-resistant environment. And it discovered that the coverlay film for conductor circuit protection of the printed wiring board using this solved the said subject, and completed this invention.

  That is, the first invention in the present invention includes a resin layer containing a polyorganosiloxane and an inorganic filler, has an average reflectance of 85% or more at a wavelength of 400 to 800 nm, and is at 260 ° C. for 10 minutes. It is a coverlay film for protecting a conductor circuit of a printed wiring board having a reflectance reduction rate at a wavelength of 450 nm after heat treatment of 5% or less.

In the first invention, it is preferable that the reflectance reduction rate at a wavelength of 450 nm after the light resistance test shown below is 5% or less.
(Light resistance test): irradiation with a xenon weather meter at a temperature of 63 ° C. (black panel temperature), a humidity of 50%, and an irradiance (295 to 400 nm) of 60 W / m ² for 50 hours.

In the first invention, the resin layer is preferably cured by radiation.
In the first invention, the inorganic filler is preferably titanium oxide.

  Moreover, in 1st invention, it is preferable that the thickness of a coverlay film is 30-500 micrometers.

  In the first invention, the average reflectance at a wavelength of 350 to 400 nm is preferably 40% or more.

In the first invention, the resin layer (A), a polyorganosiloxane, and a resin layer (B) containing an inorganic filler different from the inorganic filler contained in the resin layer (A) are provided. It is preferable that
At this time, the inorganic filler contained in the resin layer (B) is preferably alumina.

  According to a second aspect of the present invention, a protective layer having a resin layer (A) containing a polyorganosiloxane and an inorganic filler is formed on a substrate used for mounting at least one light emitting element. The protective layer has an average reflectance of 85% or more at a wavelength of 400 to 800 nm, and a reduction rate of reflectance at a wavelength of 450 nm after heat treatment at 260 ° C. for 10 minutes is 5% or less. It is the board | substrate for light emitting element mounting characterized.

According to a third aspect of the present invention, a conductor circuit is formed on a substrate, a protective layer is laminated on the conductor circuit, and the light emitting element on the substrate is mounted so that the conductor circuit and the light emitting element are electrically connected. And a light source device having a configuration in which the light emitting element is sealed with a resin.
The protective layer includes a resin layer (A) containing polyorganosiloxane and an inorganic filler, and has an average reflectance of 85% or more at a wavelength of 400 to 800 nm, and is heat-treated at 260 ° C. for 10 minutes. After that, the light source device is characterized in that the reflectance reduction rate at a wavelength of 450 nm is 5% or less.

  The cover lay film of the present invention has a high reflectivity not only in the visible light region but also in the ultraviolet region, high heat resistance, and little reduction in reflectivity under high temperature heat load environment and light resistance test environment. Can be obtained. Therefore, the coverlay film of the present invention is useful as a coverlay film for protecting a conductor circuit of a printed wiring board. And the light emitting element mounting substrate and light source device in which the conductor circuit protective layer was formed can be manufactured by using the coverlay film of this invention.

It is a figure explaining an example of one Embodiment of the light emitting element mounting substrate of this invention. It is a figure explaining an example of one Embodiment of the light emitting element mounting substrate of this invention.

  Hereinafter, embodiments of the present invention will be described. However, the scope of the present invention is not limited to this embodiment.

<This coverlay film>
The coverlay film according to the first embodiment of the present invention (referred to as “the present coverlay film”) includes a resin layer (A) containing a polyorganosiloxane and an inorganic filler, and has a wavelength of 400 to 800 nm. A coverlay film for protecting a conductor circuit of a printed wiring board having an average reflectance of 85% or more and a reduction rate of reflectance at a wavelength of 450 nm after heat treatment at 260 ° C. for 10 minutes is 5% or less.

(Reflectance)
As described above, the present coverlay film needs to have an average reflectance of 85% or more at a wavelength of 400 to 800 nm. This is because the higher the reflectance in the visible light region, the higher the luminance of the LED mounted on the substrate, and if it is in the above range, it can be suitably used as a coverlay film for the LED mounting substrate. is there. From this viewpoint, the average reflectance is preferably 90% or more, particularly 95% or more.

  In addition, since the luminance tends to increase as the reflectance near 450 nm corresponding to the average wavelength (450 nm) of the blue LED increases, the reflectance at 450 nm is more preferably 85% or more, particularly 90% or more. In particular, it is preferably 95% or more.

In addition, when obtaining white light using a currently mainstream blue LED, a reflectance around 450 nm is important. Therefore, in order to obtain white light with higher color rendering properties, a type in which an ultraviolet (near ultraviolet) LED is combined with red, green, and blue phosphors has been developed. In that case, the coverlay film may reflect both light having a wavelength of 350 to 400 nm and light having a wavelength in the visible light region (400 to 800 nm) corresponding to the emission wavelength of the ultraviolet (near ultraviolet) LED. It becomes necessary.
Therefore, the cover lay film preferably has an average reflectance of 350 to 400 nm of 40% or more, more preferably 60% or more, and particularly preferably 80% or more.

In addition, polyorganosiloxane can be used as a method for increasing the average reflectance at a wavelength of 400 to 800 nm, the reflectance at 450 nm, and the reflectance at a wavelength in the ultraviolet (near ultraviolet) region (350 to 400 nm) to a predetermined range. An inorganic filler is contained in the resin layer (A) to form a resin layer (A), thereby obtaining extremely excellent reflection characteristics, and a method of appropriately adjusting the type and content of the inorganic filler to be used. Among these, when increasing the average reflectance at a wavelength of 400 to 800 nm or the reflectance at 450 nm, it is preferable to select titanium oxide as an inorganic filler from the viewpoint of a large difference in refractive index from polyorganosiloxane. On the other hand, when increasing the reflectance of the wavelength in the ultraviolet (near ultraviolet) region (350 to 400 nm), it is preferable to select alumina as the inorganic filler.
Moreover, in order to raise the reflectance of the wavelength of both an ultraviolet (near ultraviolet) area | region (350-400 nm) and visible region (400-800 nm), in order to provide the reflectance in each wavelength, a preferable additive is added. It is also possible to mix the polyorganosiloxane separately and to laminate the resin layers made of the respective resin compositions.
However, it is not limited to these methods.

(Reduction rate of reflectivity after heat treatment)
This cover lay film requires that the reflectance reduction rate at a wavelength of 450 nm after heat treatment at 260 ° C. for 10 minutes is 5% or less of the reflectance before the heat treatment.

The grounds for the above conditions are described below.
When manufacturing an LED mounting substrate, a thermosetting process (100 to 200 ° C., several hours) of a sealing agent such as a conductive adhesive, epoxy, or silicone resin, soldering process (Pb-free solder reflow, peak temperature 260 ° C.) For several minutes), it is necessary to go through a process that requires a high thermal load, such as a wire bonding process. In addition, even in an environment where a light emitting device equipped with an LED is used, development of a high-brightness LED has progressed, the thermal load on the substrate tends to increase, and the LED element ambient temperature may exceed 100 ° C. Therefore, in the future, it will be important to maintain a high reflectance without discoloration even under such a high heat load environment.
Moreover, wavelength 450nm is an average wavelength of blue LED.

Therefore, if the reflectance decrease rate at a wavelength of 450 nm after heat treatment at 260 ° C. for 10 minutes is 5% or less of the reflectance before the heat treatment, it is possible to suppress the decrease in reflectance in the manufacturing process. In addition, since it is possible to suppress a decrease in reflectance during actual use, it can be suitably used for an LED mounting substrate.
From this viewpoint, the rate of decrease is preferably 4% or less, more preferably 3% or less, and particularly preferably 2% or less.

(Reduction rate of reflectance after light resistance test)
Moreover, it is preferable that this cover-lay film has the reflectance decreasing rate after the next light resistance test of 5% or less of the reflectance before the light resistance test.
(Light resistance test): Irradiated with a xenon weather meter at a temperature of 63 ° C. (black panel temperature), a humidity of 50%, and an irradiance (295 to 400 nm) of 60 W / m ² for 50 hours.

The grounds for the above conditions are described below.
As described above, even under the usage environment of a light emitting device equipped with an LED, development of a high-brightness LED advances and the demand for light resistance on the substrate tends to increase. Therefore, in the future, it will be necessary to have light resistance capable of maintaining a high reflectance without being discolored even in an environment in which such high output light is irradiated.

Therefore, if the reflectance decrease rate after the light resistance test is 5% or less of the reflectance before the light resistance test, it is possible to suppress the decrease in reflectance during actual use. It can be suitably used for a mounting substrate.
From this viewpoint, the rate of decrease is preferably 4% or less, more preferably 3% or less, and particularly preferably 2% or less.

  In addition, in this coverlay film, in order to make the reduction rate of the reflectance after heat treatment and the reduction rate of the reflectance after the light resistance test within a desired range, when forming the resin layer (A), polyorganosiloxane The resin composition containing the inorganic filler is preferably cured by radiation, particularly by gamma rays, as will be described later. However, it is not limited to this method.

[Resin layer (A)]
This coverlay film is provided with a resin layer (A) containing a polyorganosiloxane and an inorganic filler.

  Specifically, the polyorganosiloxane used in the coverlay film is a substance having a siloxane skeleton described in, for example, the formula (1) and capable of causing a crosslinking reaction. There is no restriction | limiting in particular as polyorganosiloxane, What is necessary is just to select and select arbitrary conventionally well-known arbitrary things.

Here, “R” in formula (1) represents an alkyl group such as a methyl group or an ethyl group, a hydrocarbon group such as a vinyl group or a phenyl group, or a halogen-substituted hydrocarbon group such as a fluoroalkyl group.
Specifically, polydimethylsiloxane in which “R” in formula (1) is all methyl groups, or a part of the methyl groups of polydimethylsiloxane is one or more of the above hydrocarbon groups or halogen-substituted hydrocarbon groups. And various polyorganosiloxanes substituted by.
As polyorganosiloxane used for this coverlay film, said polydimethylsiloxane and various polyalkylsiloxane can be used individually or in mixture of 2 or more types.

When forming the resin layer (A), the polyorganosiloxane resin may be cured.
The curing means for the polyorganosiloxane may be determined by appropriately selecting from any conventionally known methods such as addition type, condensation type, peroxide curing type and the like.

  Examples of the condensation type include dealcohol, deacetic acid, deoxime, and dehydrogenation types. Among these, it is preferable to use an addition type polyorganosiloxane that does not generate a by-product during curing.

Examples of the method for curing the polyorganosiloxane include a method of adding a curing catalyst, a method of heating at a high temperature, a method of adding a crosslinking agent, and a crosslinking method by irradiation with radiation.
Examples of the curing catalyst include aminosilane-based, nickel salt-based, and ammonium salt-based catalysts. Moreover, metal soaps, such as octylate and naphthenate, such as Al, Fe, Co, Mn, and Zn, platinum catalyst, etc. are mentioned.

  In the case of heating at a high temperature, the condition is generally 150 ° C. to 250 ° C. and can be cured by heating for about 30 minutes to 2 hours. In addition, you may add said catalyst in the case of a heating. By adding the catalyst, the heating temperature can be lowered. Specifically, the heating temperature can be set to 100 ° C. to 180 ° C., for example. And since heating time can also be shortened to about 10 minutes-about 30 minutes, it is preferable.

Especially, it is preferable to perform hardening of the resin layer (A) containing the polyorganosiloxane used for this coverlay film with a radiation.
Curing by radiation (crosslinking of the polyorganosiloxane) is a method in which heat is not applied to the polyorganosiloxane, and there is no fear of impairing the heat resistance and light resistance reliability due to the residue of the crosslinking material, and the effect of the present invention becomes remarkable. preferable.

  In the present coverlay film, examples of the radiation used for curing the polyorganosiloxane include electron beam, X-ray, and γ-ray. These radiations are widely used industrially, can be easily used, and are energy efficient. Among these, it is preferable to use γ rays having little absorption loss and high permeability.

  In the present coverlay film, a polyorganosiloxane is cured by causing a crosslinking reaction by irradiating, for example, γ rays to the uncrosslinked polyorganosiloxane. Since the crosslinking reaction can be advanced by irradiation with γ rays, the crosslinking reaction can be caused without using a crosslinking agent.

  As a result, it is possible to avoid the color change due to the crosslinking agent seen when crosslinking is performed using the crosslinking agent, and it is also possible to prevent residual by-products due to the reaction of the crosslinking agent, so that the heat resistance and light resistance are further improved. It is possible to obtain an excellent resin layer (A).

  The irradiation dose of γ rays may be appropriately selected and determined depending on the resin type, the amount of the crosslinking group, and the type of the radiation source, but is generally 10 to 150 kGy. Among these, 20 to 100 kGy is preferable, and 30 to 60 kGy is particularly preferable.

  In addition, in selecting the irradiation dose, it is preferable to take into consideration the radiation resistance of the plastic film used as the thermoplastic resin layer and the process film in addition to the crosslinking density of the polyorganosiloxane. In this respect, the crystalline polyester resin is generally a substrate excellent in resistance to radiation and suitable for the process film of the present invention.

[Inorganic filler used for resin layer (A)]
There is no restriction | limiting in particular as an inorganic filler used for the said resin layer (A), A conventionally well-known arbitrary thing can be used. For example, talc, mica, mica, glass flake, boron nitride (BN), aluminum nitride, calcium carbonate, aluminum hydroxide, silica, titanate (potassium titanate, etc.), barium sulfate, alumina, kaolin, clay, titanium oxide, Examples thereof include zinc oxide, zinc sulfide, lead titanate, zircon oxide, antimony oxide, and magnesium oxide. These may be added singly or in combination of two or more.

  The inorganic filler used in the resin layer (A) is further coated with a silicone compound or a polyhydric alcohol based on the surface of the inorganic filler in order to improve dispersibility in the resin layer (A) made of polyorganosiloxane. What was surface-treated with a compound, an amine compound, a fatty acid, a fatty acid ester or the like can be used. Of these, those treated with silicone compounds (such as siloxane and silane coupling agents) are preferred.

As the inorganic filler used for the resin layer (A), it is preferable to use a material having a large refractive index difference from the polyorganosiloxane in consideration of the light reflectivity of the present coverlay film. Among them, those having a refractive index of 1.6 or more are preferable, and specifically, for example, among those described above, calcium carbonate, barium sulfate, zinc oxide, titanium oxide, titanate and the like can be mentioned, and titanium oxide is particularly preferable. .
Alumina is preferred from the viewpoint of increasing the reflectance in the low wavelength region.

  Titanium oxide has a significantly higher refractive index than other inorganic fillers, and can increase the difference in refractive index from polyorganosiloxane as the base resin, so it is less than when other fillers are used. It is preferable because excellent reflectivity can be obtained by the blending amount.

  In the resin layer (A), as the titanium oxide to be blended with the polyorganosiloxane, a crystalline titanium oxide such as anatase type or rutile type is preferable, and in particular, from the viewpoint of increasing the difference in refractive index from the polyorganosiloxane, Rutile type titanium oxide is preferred.

  In the case of a coverlay film applied to a substrate that uses an element of a combination of ultraviolet (near-ultraviolet) LEDs and red, green, and blue phosphors as a semiconductor light emitting element, the coverlay film is also ultraviolet (nearly near). It is necessary to reflect light having a wavelength of 350 to 400 nm corresponding to the emission wavelength of the ultraviolet) LED and to reflect light having a wavelength in the visible light region (400 to 800 nm). The anatase type with less light absorption is preferred.

  The production method of titanium oxide generally includes a chlorine method and a sulfuric acid method, but as the production method of titanium oxide used in the present invention, it is preferable to use titanium oxide produced by the chlorine method from the viewpoint of whiteness. .

  The titanium oxide is preferably one whose surface is coated with an inert inorganic oxide. By coating the surface of titanium oxide with an inert inorganic oxide, the photocatalytic activity of titanium oxide can be suppressed, and deterioration of the coverlay film of the present invention can be suppressed, which is preferable.

  Specifically, as the inert inorganic oxide, for example, it is preferable to use at least one selected from the group consisting of silica, alumina, and zirconia. Use of these inert inorganic oxides is preferable because it can suppress a decrease in molecular weight and yellowing of the resin during high-temperature melting without impairing high reflectivity.

  Further, the titanium oxide has at least one inorganic compound selected from the group consisting of a siloxane compound, a silane coupling agent, etc., a group consisting of a polyol, polyethylene glycol, etc., in order to enhance the dispersibility in the resin composition. Those subjected to surface treatment with at least one organic compound selected from In particular, those treated with a silane coupling agent are preferred from the viewpoint of heat resistance, and those treated with a siloxane compound are preferred from the viewpoint of dispersibility.

  The particle size of the inorganic filler used for the resin layer (A) is arbitrary, and may be appropriately selected and determined according to the use and thickness of the coverlay film of the present invention. In general, a film having a particle size equal to or smaller than the thickness of the cover lay film is used, and specifically, for example, the average particle size is preferably 0.05 to 50 μm, more preferably 0.1 to 30 μm, and particularly preferably 0.00. It is preferable that it is 15-15 micrometers.

  If the particle size of the inorganic filler is 0.05 μm to 50 μm, the dispersibility in the resin is good, the interface with the resin is densely formed, and high reflectivity can be imparted, which is preferable.

  In particular, when titanium oxide is used as the inorganic filler used in the resin layer (A), the particle size is preferably 0.1 μm to 1.0 μm, and more preferably 0.2 μm to 0.5 μm. Is preferred. If the particle size of titanium oxide is in the above range, the dispersibility in the resin is good, the interface with the resin is densely formed, and high reflectivity can be imparted, which is preferable.

  The content of the inorganic filler used in the resin layer (A) is preferably 10 to 1000 parts by mass, more preferably 20 to 500 parts by mass, and more preferably 25 to 200 parts by mass with respect to 100 parts by mass of the polyorganosiloxane. In particular, it is preferably 30 to 100 parts by mass. Within this range, it is preferable because good reflection characteristics can be obtained and good reflection characteristics can be obtained even when the film thickness is reduced.

[Resin layer (B)]
The cover lay film includes a resin layer (B) containing a polyorganosiloxane and an inorganic filler different from the inorganic filler contained in the resin layer (A) separately from the resin layer (A). You can also.
For example, the resin layer (A) has a high reflectance in the visible light region (400 to 800 nm), and the resin layer (B) has a high reflectance in the ultraviolet (near ultraviolet) region (350 to 400 nm). It is possible to combine resin layers (A) and (B) having different actions such as forming layers.

  The polyorganosiloxane of the resin layer (B) is not particularly limited as in the case of the resin layer (A) described above, and may be determined by appropriately selecting any conventionally known one. Moreover, the means similar to the resin layer (A) mentioned above can also be used for the polyorganosiloxane curing means.

[Inorganic filler used for resin layer (B)]
The inorganic filler used for the resin layer (B) is not particularly limited as long as it is an inorganic filler different from the inorganic filler contained in the resin layer (A). For example, talc, mica, mica, glass flake, boron nitride (BN), aluminum nitride, calcium carbonate, aluminum hydroxide, silica, titanate (potassium titanate, etc.), barium sulfate, alumina, kaolin, clay, titanium oxide, Examples thereof include zinc oxide, zinc sulfide, lead titanate, zircon oxide, antimony oxide, and magnesium oxide. These may be added singly or in combination of two or more.

  For example, when the inorganic filler used for the resin layer (A) is titanium oxide, particularly when it is rutile type titanium oxide, light absorption occurs in the ultraviolet (near ultraviolet) region (350 to 400 nm), so the resin layer As the inorganic filler used in (B), it is preferable to select anatase-type titanium oxide or alumina that has low light absorption in the 400 nm region.

  Furthermore, when the coverlay film comprising the resin layers (A) and (B) is used for the “substrate for mounting a light-emitting element” described later, anatase-type titanium oxide that absorbs less light in the 400 nm region as an inorganic filler. Or it is preferable to laminate | stack with a metal layer so that the resin layer (B) using an alumina may become a use surface (it may become the exposed side). Thereby, the light in the ultraviolet (near ultraviolet) region (350 to 400 nm) is reflected by the resin layer (B), and the light in the visible light region (400 to 800 nm) contains the resin layer (B) and the rutile titanium oxide. Therefore, the reflectance can be increased in a wide wavelength region.

  The particle size of the inorganic filler used for the resin layer (B) is arbitrary, and may be appropriately selected and determined according to the use and thickness of the coverlay film of the present invention. In general, a film having a particle size equal to or less than the thickness of the cover lay film is used. For example, the average particle size is preferably 0.05 to 50 μm, more preferably 0.1 μm or more and 30 μm or less. More preferably, it is 15 μm or more or 15 μm or less.

  If the particle size of the inorganic filler is 0.05 μm to 50 μm, the dispersibility in the resin is good, the interface with the resin is densely formed, and high reflectivity can be imparted, which is preferable.

  The content of the inorganic filler used in the resin layer (B) is preferably 10 to 1000 parts by mass with respect to 100 parts by mass of the polyorganosiloxane, especially 20 parts by mass or more and 500 parts by mass or less, and 30 parts by mass among them. Part or more or 300 parts by mass or less, more preferably 50 parts by mass or more or 200 parts by mass or less. Within this range, it is preferable because good reflection characteristics can be obtained and good reflection characteristics can be obtained even when the film thickness is reduced.

(Additives, etc.)
The resin layer (A) and the resin layer (B) may contain various additives other than other resins and inorganic fillers as long as the properties are not impaired. For example, a heat stabilizer, an ultraviolet absorber, a light stabilizer, a nucleating agent, a colorant, a lubricant, a flame retardant, and the like may be appropriately blended.

(Thickness of coverlay film)
The thickness of the cover lay film is not particularly limited and may be appropriately selected and determined. Generally, it is 1 μm to 1000 μm, and in the present coverlay film, it is preferably 10 μm to 1000 μm. Among them, 10 μm to 800 μm, further 20 μm to 500 μm, particularly 20 μm to 300 μm, particularly 30 μm to 200 μm are preferable.
Further, when the effect of the present invention that the rate of decrease in reflectance is small is obtained in a high reflectance region, the thickness of the cover lay film is preferably 50 μm or more, particularly 100 μm, The upper limit is usually 1000 μm, preferably 500 μm.

  Within such a range, it is possible to ensure reflectivity as a cover circuit film for protecting a conductor circuit of a chip LED mounting substrate used as a surface light source for a mobile phone backlight or a liquid crystal display backlight that requires thinness. Therefore, it can be preferably used. Also, when used as a dam material, the thickness is sufficient to seal LED chips and gold wires.

(Coverlay film manufacturing method)
The method for preparing the resin composition for forming the resin layer (A) and the resin layer (B), that is, the resin composition for forming the resin layer containing polyorganosiloxane is not particularly limited. A known method can be used. For example, (a) A master batch prepared by mixing various additives with a suitable base resin such as polyorganosiloxane at a high concentration (typically 10 to 90% by weight) is prepared separately and used. A method of adjusting the concentration of the resin to be mixed and mechanically blending using a kneader or an extruder can be given. In addition, (b) a method in which various additives are mechanically blended directly with a resin to be used using a kneader, an extruder, or the like.
Among these methods, from the viewpoint of dispersibility and workability, a method of preparing and mixing the master batch (a) is preferable.

Next, as a method of forming the resin composition, a known film forming method, for example, an extrusion cast using a T-die using a resin composition obtained by mixing polyorganosiloxane and an inorganic filler. Examples thereof include a method of forming a film by a method, a calendering method, or a method of coating on a base film (PET film or the like).
What is necessary is just to harden the polyorganosiloxane of an uncrosslinked state by heat curing, radiation curing, etc. for the film formed in this way.

(Application of coverlay film)
This cover lay film can be used as a cover lay film for protecting a conductor circuit of a printed wiring board. For example, a conductor circuit is formed on a substrate, and this cover lay film is laminated on the conductor circuit, while a light emitting element is mounted on the substrate so that the conductor circuit and the light emitting element are electrically connected. can do. At this time, by laminating the coverlay film, it is possible to prevent the conductor circuit from being damaged and disconnected, and to prevent a short circuit due to solder adhesion when the light emitting element is mounted. Can exhibit functions such as preventing a finger from touching the power terminal portion and receiving an electric shock.

<Substrate for mounting this light emitting element>
A light-emitting element mounting substrate (referred to as a “light-emitting element mounting substrate”) according to the second embodiment of the present invention includes a polyorganosiloxane and a substrate used for mounting at least one light-emitting element. A protective layer having a resin layer (A) containing an inorganic filler, the protective layer having an average reflectance of 85% or more at a wavelength of 400 to 800 nm, and a wavelength after heat treatment at 260 ° C. for 10 minutes; The light emitting element mounting substrate is characterized in that a reflectance reduction rate at 450 nm is 5% or less.

  In the present light emitting element mounting substrate, there are no particular limitations on the shape and material of the substrate and the like, provided that the above-described conditions are satisfied, and any conventionally known one can be used. Specifically, for example, “a substrate used for mounting a light emitting element” is a resin / metal laminate in which a metal layer is laminated on at least one surface of a resin substrate material made of a thermosetting resin or a thermoplastic resin. In addition, a configuration in which a wiring pattern (conductor circuit) is formed on at least one surface of the resin substrate material can be exemplified.

  If a protective layer having a resin layer containing a polyorganosiloxane and an inorganic filler having the above-mentioned specific properties is formed on such a “substrate used for mounting a light-emitting element”, that is, the above-mentioned book If a cover lay film is laminated | stacked, it will become possible to protect a conductor circuit. And since the said protective layer has a high reflectance, it also exhibits the function as a reflector and has the outstanding effect of contributing to the improvement of the reflectance of this board | substrate.

(Metal layer)
Examples of the metal layer in the resin / metal laminate used for the light emitting element mounting substrate include copper, gold, silver, aluminum, nickel, tin, and the like. The thickness of the metal layer is arbitrary, and may be appropriately selected and determined. Usually, it is 1 μm to 100 μm, preferably 5 μm to 70 μm.

  Of these, copper and copper alloys are preferred as the metal species, and those having the surface subjected to chemical conversion treatment such as black oxidation treatment are preferred. In order to enhance the adhesion effect, it is preferable to use a conductive foil that is a metal layer that has been chemically or mechanically roughened on the contact surface (surface to be overlapped) side with the coverlay film. Specific examples of the conductor foil that has been subjected to the surface roughening treatment include, for example, a roughened copper foil that has been electrochemically treated when an electrolytic copper foil is produced.

  Further, the resin / metal laminate that is the substrate used for the light emitting element mounting substrate may be a laminate of a plurality. In this lamination method, a known method can be adopted as a heat fusion method without using an adhesive layer as long as it is a method by heating and pressurization. For example, a heat press method, a heat laminating roll method, and extrusion are used. An extrusion laminating method in which the resin is laminated with a cast roll, or a method combining these can be suitably employed.

  In addition, as the “substrate used for mounting the light emitting element”, in place of the resin / metal laminate as described above, a metal material such as a copper plate or an aluminum plate, aluminum nitride, or the like is used when more heat dissipation is required. It is also possible to improve heat dissipation by combining with a material having high thermal conductivity such as a ceramic or a graphite plate.

  For example, as a composite substrate structure with an aluminum plate, the above-mentioned metal laminate is laminated on the entire surface of the aluminum plate, or a window frame for a cavity (recess) structure is removed from the metal laminate and laminated. If you want to. The aluminum to be used is preferably roughened in consideration of the adhesion to the resin, but when considering the cavity structure, in order to efficiently reflect the light from the LED, highly reflective aluminum is used. It is preferable to use it.

  Examples of the highly reflective aluminum include those whose surfaces are polished, alumite-treated, and those subjected to a reflective film treatment in which a metal such as silver is vapor-deposited in addition to inorganic oxides such as titanium and silica. The aluminum reflectance is preferably 80% or more, more preferably 90% or more, and particularly preferably 95% or more.

(Manufacturing method of light emitting element mounting substrate)
The manufacturing method of this light emitting element mounting substrate is arbitrary, and is not particularly limited. Here, first, as a specific method for manufacturing the light emitting element mounting substrate, a method for manufacturing a double-sided substrate in which metal layers are laminated on both sides of the substrate will be described with reference to FIG.

  As shown in FIG. 1, (a): First, a substrate (100) made of a thermoplastic resin or a thermosetting resin and two copper foils (10) to be a metal layer are prepared, and (b): A copper foil (10) is laminated on both sides of a substrate (100) made of a thermoplastic resin or a thermosetting resin by a vacuum press to produce a resin / metal laminate.

  (C): Then, the copper foil (10) is etched or plated on copper to form a wiring pattern (20), and a “substrate used for mounting a light emitting element” is produced. (D): A protective layer (200) provided with a resin layer (30) containing an inorganic filler in polyorganosiloxane, in which a mounting location is subjected to window processing, is laminated on this substrate (in addition, Here, the cover lay film is laminated), and the light emitting element mounting substrate is used.

  (E): After that, gold plating is performed, the LED (300) is mounted, the wiring pattern (20) is connected by the bonding wire (40), and sealed with a predetermined resin (not shown). It can be.

  In addition, the method of window-cutting is arbitrary and is not particularly limited. Specifically, for example, a method using a big die, a router processing method, a laser processing method, or the like can be used. In addition to the above, the protective layer may be formed by applying a resin layer (30) containing polyorganosiloxane and an inorganic filler.

Next, a manufacturing method of the light emitting element mounting substrate as the aluminum composite substrate will be described with reference to FIG.
For example, as shown in FIG. 2, (a): a copper foil (10) is laminated on one side of a substrate (100) made of a thermoplastic resin or a thermosetting resin to produce a metal laminate. And (b): The copper foil (10) is etched to form a wiring pattern (20), gold plating is performed, and the substrate (100) is punched into a cavity frame using a big die (50).

  Next, (c): an aluminum plate (400) is laminated by a vacuum press on the surface opposite to the surface on which the protective layer (200) and the wiring pattern (20) are formed, thereby forming a light emitting element mounting substrate. . (D): LED (300) is mounted on this substrate, connected to wiring pattern (20) with bonding wire (40), and sealed with a predetermined resin (not shown) to form a light source device. Can do.

  Note that the method of punching into the cavity frame is not limited to the method using the Bic die, and can be formed by, for example, router processing or laser. In addition, in the said manufacturing method, although lamination | stacking of the film with a single-sided copper foil ((b) in FIG. 2), a protective layer, and an aluminum plate is performed collectively, these are laminated | stacked sequentially, and frame extraction is carried out after that. In addition, a conductor pattern may be formed.

<Light source device>
As a light source device according to the third embodiment of the present invention (referred to as “the present light source device”), a conductive circuit is formed on the substrate for mounting the light emitting element, and the substrate and the light emission mounted on the substrate. There is no particular limitation as long as the element is electrically connected and the light emitting element is sealed with resin. Specifically, a conductor circuit is formed on a substrate, a protective layer is laminated on the conductor circuit, and the light emitting element on the substrate is mounted to make the conductor circuit and the light emitting element conductive, and the light emitting element The thing of the structure formed by resin-sealing can be mentioned.

  Since the protective layer in the light source device has the characteristics of the resin layer (A), for example, the average reflectance at a wavelength of 400 to 800 nm is 85% or more, and the wavelength is 450 nm after heat treatment at 260 ° C. for 10 minutes. In other words, the reflectance is decreased by 5% or less. Therefore, by forming the protective layer in this way, it becomes possible to effectively protect the conductor circuit, which causes a decrease in reflectivity even under high temperature heat load environment and light resistance test environment. Therefore, the light source device of the present invention can be used for various applications such as lighting, projector light sources, backlight devices such as liquid crystal display devices, in-vehicle applications, and mobile phone applications.

<Explanation of words>
“Sheet” generally refers to a product that is thin by definition in JIS and generally has a thickness that is small and flat for the length and width. In general, “film” is compared to the length and width. A thin flat product having an extremely small thickness and an arbitrarily limited maximum thickness, usually supplied in the form of a roll (Japanese Industrial Standard JISK6900). For example, in terms of thickness, in the narrow sense, a film having a thickness of 100 μm or more is sometimes referred to as a sheet, and a film having a thickness of less than 100 μm is sometimes referred to as a film. However, since the boundary between the sheet and the film is not clear and it is not necessary to distinguish the two in terms of the present invention, in the present invention, even when the term “film” is used, the term “sheet” is included and the term “sheet” is used. In some cases, “film” is included.

In the present specification, when expressed as “X to Y” (X and Y are arbitrary numbers), unless otherwise specified, “X is preferably greater than X” or “preferably Y”. It also includes the meaning of “smaller”.
In addition, when expressed as “X or more” (X is an arbitrary number) or “Y or less” (Y is an arbitrary number), it is “preferably greater than X” or “preferably less than Y”. Includes intentions.

Hereinafter, it demonstrates further more concretely by an Example and a comparative example. However, the present invention is not limited to the following examples unless it exceeds the gist.
In addition, the various measured values and evaluation about the film etc. which are shown in this specification were calculated | required as follows.

(Average reflectance)
An integrating sphere is attached to a spectrophotometer ("U-4000", manufactured by Hitachi, Ltd.), and the reflectance when the reflectance of the alumina white plate is 100% is measured at intervals of 0.5 nm over a wavelength range of 400 nm to 800 nm. It was measured. The average value of the measured values obtained was calculated, and this value was taken as the average reflectance. And the average reflectance of wavelength 350-400 nm was measured similarly.

(Reflectance after heat treatment)
The obtained white film was fixed with a fixing jig, heated in a hot air circulation oven at 260 ° C. for 10 minutes, the reflectance after the heat treatment was measured in the same manner as described above, and the reflectance at 450 nm was read. It was.

(Test with xenon weather meter)
Using the xenon weather meter (model: SX-75) manufactured by Suga Test Instruments Co., Ltd., the obtained coverlay film was temperature 63 ° C. (black panel temperature), humidity 50%, irradiance (295-400 nm) 60 W / m. ² was irradiated for 50 hours, followed by measuring the above method as well as the reflectance was read reflectance at 450nm.

<Example 1>
Resin obtained by mixing 100 parts by mass of polyorganosiloxane (TSE2571-5U, manufactured by Momentive) and 67 parts by mass of rutile titanium oxide (R105, manufactured by DuPont, average particle size 0.31 μm) with a planetary mixer. A coverlay film precursor having a thickness of 100 μm was obtained on the release PET film at a set temperature of 100 ° C. using an extruder. Then, the coverlay film which consists of a resin layer (A) obtained by making it harden | cure by the irradiation dose of 50 kGy with a gamma ray was evaluated by the method mentioned above. The results are shown in Table 1.

<Example 2>
1.5 parts by mass of a vulcanizing agent (TC-12, manufactured by Momentive) as a thermal crosslinking material and 100 parts by mass of polyorganosiloxane (TSE2571-5U, manufactured by Momentive), titanium oxide (R105, manufactured by DuPont) , Average particle size 0.31 μm) A cover lay film having a thickness of 100 μm on a release PET film with a resin composition obtained by mixing 67 parts by mass with a planetary mixer at a set temperature of 100 ° C. using an extruder. A precursor was obtained. Then, the coverlay film which consists of the resin layer (A) obtained by making it heat-process at 125 degreeC for 15 minutes and then heat-treating at 200 degreeC for 4 hours was evaluated. The results are shown in Table 1.

<Example 3>
A coverlay film made of the resin layer (A) was prepared and evaluated in the same manner as in Example 1 except that the thickness was 300 μm. The results are shown in Table 1.

<Example 4>
A coverlay film made of the resin layer (A) was produced and evaluated in the same manner as in Example 1 except that the titanium oxide was changed to 400 parts by mass. The results are shown in Table 1.

<Example 5>
A coverlay film made of the resin layer (A) was prepared and evaluated in the same manner as in Example 1 except that the titanium oxide was changed to 25 parts by mass. The results are shown in Table 1.

<Example 6>
A coverlay film made of the resin layer (A) was produced and evaluated in the same manner as in Example 1 except that the thickness was 50 μm. The results are shown in Table 1.

<Example 7>
The resin layer (A) was prepared in the same manner as in Example 1 except that 25 parts by mass of anatase-type titanium oxide (SA-1, Sakai Chemical Industry Co., Ltd., average particle size: 0.3 μm) was used as titanium oxide. A coverlay film consisting of was prepared and evaluated. The results are shown in Table 1.

<Example 8>
A coverlay film composed of the resin layer (A) was prepared and evaluated in the same manner as in Example 1 except that polyorganosiloxane (TSE2913-U, manufactured by Momentive) was used as the polyorganosiloxane. The results are shown in Table 1.

<Example 9>
A cover lay film comprising a resin layer (A) in the same manner as in Example 1 except that 150 parts by mass of alumina (AA04, manufactured by Sumitomo Chemical Co., Ltd., average particle size 0.4 μm) was used instead of titanium oxide. Were made and evaluated. The results are shown in Table 1.

<Example 10>
A coverlay film made of the resin layer (A) was prepared and evaluated in the same manner as in Example 8 except that the thickness was 150 μm. The results are shown in Table 1.

<Example 11>
A coverlay film made of the resin layer (A) was prepared and evaluated in the same manner as in Example 9 except that the thickness was 150 μm. The results are shown in Table 1.

<Example 12>
After obtaining a coverlay film precursor composed of a resin layer (A) having a thickness of 100 μm by the same method as in Example 8, the resin layer (B) having a thickness of 50 μm was obtained in the same manner as in Example 9. A coverlay film precursor was prepared, and the coverlay film surfaces of both precursors were bonded together, and then a coverlay film having a laminated structure cured with γ rays was prepared and evaluated. The results are shown in Table 1. In addition, the measurement of the reflectance measured the surface which consists of a resin layer (B).

<Example 13>
A coverlay film having a laminated structure was prepared and evaluated in the same manner as in Example 12 except that the thickness of the resin layer (B) was 100 μm. The results are shown in Table 1. In addition, the measurement of the reflectance measured the surface which consists of a resin layer (B).

<Comparative Example 1>
For 100 parts by mass of a resin composition comprising 40% by mass of a polyether ether ketone resin (PEEK450G, Tm = 335 ° C.) and 60% by mass of an amorphous polyetherimide resin (Ultem 1000), a rutile type titanium oxide ( R108, manufactured by DuPont, average particle size of 0.23 μm) 67 parts by mass was melt-kneaded, and using an extruder equipped with a T-die at a set temperature of 380 ° C. and a thickness of 100 μm A coverlay film was prepared and evaluated in the same manner as in Example 1. The results are shown in Table 1.

  As can be seen from the results shown in Table 1, in Examples 1 to 13 of the present invention, the reflectance characteristics are good, and the reflectance changes even after the heating test and after the light resistance test (xenon weather meter test). A few excellent coverlay films could be obtained. For example, in Examples 9 and 11, since polyorganosiloxane is filled with alumina, the reflectance in the visible light region is higher than that in the comparative example, but the reflectance in the ultraviolet light region (350 to 400 nm) is remarkably high. It has improved. On the other hand, in Comparative Example 1, the reflectance in the visible light region and the reflectance after the light resistance test were inferior.

  Examples 1 to 8 and 10 exhibited a particularly high reflectance even in the visible light region (400 to 800 nm) because polyorganosiloxane was filled with titanium oxide. And since Example 7 was filled with the anatase type titanium oxide, the reflectance of the ultraviolet light region showed the high reflectance compared with Examples 1-6, 8 and 10 with which the rutile type was filled.

  Furthermore, in Example 12 and 13, by setting it as the laminated structure of the resin layer (A) which filled the polyorganosiloxane with the rutile type titanium oxide, and the resin layer (B) which filled the polyorganosiloxane with the alumina, High reflectivity was exhibited in both the ultraviolet light region (350 to 400 nm) and the visible light region (400 to 800 nm).

10 Copper foil 20 Wiring pattern 30 Resin layer 40 containing polyorganosiloxane and inorganic filler Bonding wire 100 Substrate 200 made of thermoplastic resin or thermosetting resin Protective layer 300 LED
400 aluminum plate

Claims (10)

  The resin layer (A) containing a polyorganosiloxane and an inorganic filler is provided, the average reflectance at a wavelength of 400 to 800 nm is 85% or more, and the reflection at a wavelength of 450 nm after heat treatment at 260 ° C. for 10 minutes. A coverlay film for protecting a conductor circuit of a printed wiring board having a rate of decrease of 5% or less. The coverlay film according to claim 1, wherein the reflectance reduction rate after the light resistance test shown below is 5% or less.
(Light resistance test): Irradiated with a xenon weather meter at a temperature of 63 ° C. (black panel temperature), a humidity of 50%, and an irradiance (295 to 400 nm) of 60 W / m ² for 50 hours.   The coverlay film according to claim 1 or 2, wherein the resin layer (A) is a layer formed by curing with radiation.   The coverlay film according to any one of claims 1 to 3, wherein the inorganic filler contained in the resin layer (A) is titanium oxide.   The coverlay film according to claim 1, wherein the film has a thickness of 30 μm to 500 μm.   The coverlay film according to any one of claims 1 to 5, wherein an average reflectance at a wavelength of 350 to 400 nm is 40% or more.   The resin layer (A), a polyorganosiloxane, and a resin layer (B) containing an inorganic filler different from the inorganic filler contained in the resin layer (A) are provided. Item 7. The coverlay film according to any one of Items 1 to 6.   The coverlay film according to claim 7, wherein the inorganic filler contained in the resin layer (B) is alumina. Comprising a structure in which a protective layer having a resin layer (A) containing polyorganosiloxane and an inorganic filler is formed on a substrate used for mounting at least one light-emitting element;
The protective layer has an average reflectance of 85% or more at a wavelength of 400 to 800 nm, and a reduction rate of reflectance at a wavelength of 450 nm after heat treatment at 260 ° C. for 10 minutes is 5% or less. Device mounting board. A conductor circuit is formed on the substrate, a protective layer is laminated on the conductor circuit, and a light emitting element is mounted on the substrate to make the conductor circuit and the light emitting element conductive, and the light emitting element is sealed with resin. In the light source device having a configuration formed by
The protective layer includes a resin layer (A) containing polyorganosiloxane and an inorganic filler, and has an average reflectance of 85% or more at a wavelength of 400 to 800 nm, and is heat-treated at 260 ° C. for 10 minutes. After that, the light source device is characterized in that the reflectance decrease rate at a wavelength of 450 nm is 5% or less.