JP6115593B2 - Thermosetting silicone resin sheet having phosphor-containing layer and phosphor-free layer, light-emitting device manufacturing method using the same, and sealed light-emitting semiconductor device - Google Patents

Description

  The present invention has at least a phosphor-containing layer and a phosphor-free layer silicone resin layer capable of converting the wavelength of blue light and ultraviolet light of an LED by being laminated and bonded to the chip surface of the LED element. The present invention relates to a thermosetting silicone resin sheet, a method for producing a light emitting device using the same, and the light emitting device.

  In the field of light emitting diodes (LEDs), it is known to use a phosphor for wavelength conversion (Patent Document 1). Silicone resin is attracting attention as a material for sealing and protecting LED elements because of its excellent light resistance (Patent Document 2).

  In general, in a white LED, the phosphor is dispersed in the vicinity of the chip by a method such as coating the LED chip with a silicone resin or an epoxy resin in which the phosphor is dispersed to convert blue light into pseudo white light. However, if the dispersion of the phosphor in the resin layer is non-uniform or uneven, a color shift is likely to occur. Therefore, in order to create uniform white light, the phosphor may be uniformly dispersed in the coating resin layer. is necessary. Therefore, for example, a method of screen printing a silicone resin composition containing a phosphor has been studied. In addition, after applying the composition to the chip, the phosphor is uniformly dispersed in the vicinity of the chip by sedimentation, and a method of forming a transparent or translucent protective layer on the phosphor dispersion layer thus obtained is studied. Has been. However, this method has a problem that the quality of the obtained phosphor dispersion layer and the protective transparent layer is insufficiently stable and the manufacturing process becomes complicated. In addition, conventionally, a thermosetting silicone resin sheet containing a phosphor is attached on an LED element and cured, and then a transparent resin is cast to form a protective layer. This method also has a problem that the manufacturing process is complicated (Patent Document 3).

  Moreover, in LED etc., high heat resistance, ultraviolet-ray resistance, etc. are calculated | required by the resin layer which coat | covers an LED element. Furthermore, it is advantageous that a resin layer in which such phosphors are uniformly dispersed can be formed by a conventional manufacturing apparatus.

JP 2005-524737 A JP 2004-339482 A JP 2009-094351 A

  Then, the subject of this invention is providing the thermosetting silicone resin sheet which can disperse | distribute fluorescent substance uniformly on the LED element surface easily.

As the present invention solves the above problems, first,
A layer (2) comprising a thermosetting silicone resin composition containing a phosphor in a solid or semisolid state that is plastic at room temperature, and a thermosetting property that is transparent or translucent in a plastic solid or semisolid state at room temperature A thermosetting silicone resin sheet comprising a layer (1) comprising a silicone resin composition is provided.

  The thermosetting silicone resin sheet of the present invention can be applied to the surface of the LED element and cured and sealed by heat.

  Furthermore, the present invention secondly includes the phosphor-containing cured silicone resin layer and the phosphor by disposing the thermosetting silicone resin sheet on the surface of the LED element and heating and curing the resin sheet. The manufacturing method of the light-emitting device which has a LED element which coat | covers and seals the LED element surface with the hardened | cured material which has a cured silicone resin layer which does not perform is also provided.

  Furthermore, this invention provides the light-emitting device by which the LED element was sealed with the hardened | cured material which has the hardening silicone resin layer which does not contain the fluorescent substance containing hardening silicone resin layer and fluorescent substance obtained by this manufacturing method.

As a particularly preferred embodiment of the thermosetting silicone resin sheet of the present invention,
Said layer (2) is

(A) substantially consisting of R ¹ SiO _1.5 units, R ² ₂ SiO units, and R ³ _a R ⁴ _b SiO _{(4-ab) / 2} units (where R ¹ , R ² , and R ³ are Independently represents a methyl group, an ethyl group, a propyl group, a cyclohexyl group, or a phenyl group, R ⁴ independently represents a vinyl group or an allyl group, a is 0, 1 or 2, b is 1 or 2, and a + b is 2 or 3.), an organopolysiloxane having a resin structure in which at least a part of the R ² ₂ SiO unit is continuously repeated, and the number of repetitions thereof is 5 to 300;

(B) substantially composed of R ¹ SiO _1.5 unit, R ² ₂ SiO unit, and R ³ _c H _d SiO _{(4-cd) / 2} unit (where R ¹ , R ² and R ³ are independently As described above, c is 0, 1 or 2, d is 1 or 2, and c + d is 2 or 3.)
Organohydrogenpolysiloxane having a resin structure in which at least a part of the R ² ₂ SiO unit is continuously repeated and the number of repetitions thereof is 5 to 300:
(A) The quantity which becomes 0.1-4.0 by the molar ratio of the hydrogen atom couple | bonded with the silicon atom in (B) component with respect to the sum total of the vinyl group and allyl group in a component,

(C) a platinum group metal catalyst: a curing effective amount, and (D) a thermosetting silicone resin composition containing a phosphor,

Said layer (1) is
(A) substantially comprising R ¹ SiO _1.5 units, R ² ₂ SiO units, and R ³ _a R ⁴ _b SiO _{(4-ab) / 2} units (where R ¹ , R ² , and R ³ independently represents a methyl group, an ethyl group, a propyl group, a cyclohexyl group, or a phenyl group, R ⁴ independently represents a vinyl group or an allyl group, a is 0, 1 or 2, and b is 1 or 2. A + b is 2 or 3.), an organopolysiloxane having a resin structure including a structure in which at least a part of the R ² ₂ SiO unit is continuously repeated, and the number of repetitions thereof is 5 to 300,

(B) substantially comprising R ¹ SiO _1.5 units, R ² ₂ SiO units, and R ³ _c H _d SiO _{(4-cd) / 2} units (where R ¹ , R ² and R ³ are Independently as described above, c is 0, 1 or 2, d is 1 or 2, and c + d is 2 or 3.)
Organohydrogenpolysiloxane having a resin structure in which at least a part of the R ² ₂ SiO unit is continuously repeated and the number of repetitions thereof is 5 to 300:
(A) The amount of hydrogen atoms bonded to silicon atoms in component (B) relative to the total of vinyl groups and allyl groups in component (A) in a molar ratio of 0.1 to 4.0, and

(C) Platinum group metal-based catalyst: A thermosetting silicone resin sheet comprising a thermosetting silicone resin composition containing an effective amount of curing and not containing a phosphor may be mentioned.

  The thermosetting silicone resin sheet of the present invention (the sheet has at least two layers, but for convenience of explanation, hereinafter also referred to as a two-layer thermosetting silicone resin sheet) is an uncured plastic solid or semi-solid. Since it is solid, it is easy to handle and has good workability, so it can be easily laminated and bonded to the surface of the LED chip. Also, since it is a plastic solid or semi-solid in an uncured state, the dispersion state of the filled phosphor is stable over time and does not separate from the resin or settle during storage. The resin layer in which is uniformly dispersed can be stably maintained.

In the case of the two-layer thermosetting silicone resin sheet of the present invention, the phosphor layer and the protective layer (sealing layer) can be formed at the same time by sticking this one on the LED chip surface, so the productivity is also greatly improved. It is excellent in mass productivity. The two-layer thermosetting silicone resin sheet can be easily laminated and adhered to the surface of the LED chip even with a mounting device such as a normal die bond mounter.
Then, by curing the composition sheet thus laminated, a cured resin layer in which the phosphor is uniformly dispersed can be efficiently and stably formed with a uniform layer thickness. Further, in the obtained phosphor resin layer, since the phosphor is uniformly dispersed, color misregistration hardly occurs, the color rendering property is good, and uniform white light can be obtained.

  When the composition of the preferred embodiment described above is used, a cured resin layer having excellent flexibility and less surface tack is formed while the cured product is a hard resin. In addition, there is an advantage that the conventional molding apparatus can be easily molded.

1 is a cross-sectional view showing the structure of a thermosetting silicone resin sheet of the present invention produced in Example 1. FIG. It is a conceptual diagram explaining sealing of the LED element arranged on the ceramic substrate. It is a conceptual diagram explaining sealing of the LED element mounted in the reflector. It is a conceptual diagram explaining sealing of the LED element joined by the flip chip system.

Hereinafter, the present invention will be described in more detail.
The thermosetting silicone resin sheet of the present invention comprises at least a layer (2) and a layer (1), both of which are plastic solids or semisolids at room temperature. Here, “normal temperature” means an ambient temperature in a normal state, and is usually in the range of 15 to 30 ° C., typically 25 ° C. “Semi-solid” refers to a state of a material that is plastic and can retain its shape when molded into a particular shape for at least 1 hour, preferably 8 hours or longer. Thus, for example, a flowable material having a very high viscosity at room temperature is essentially flowable, but changes to the applied shape in a short time of at least 1 hour (ie, breakage) due to the very high viscosity. ) Cannot be seen with the naked eye, the substance is in a semi-solid state. Since the composition is in a solid or semi-solid state, the composition has good handleability and high workability. In the layer (2), a good dispersion state of the phosphor is maintained over time.

  The thermosetting silicone resin sheet of the present invention is in such a plastic solid or semi-solid state at room temperature, but begins to be cured by heating. In the curing process, the phenomenon first softens. That is, in the solid state, the fluidity is slightly exhibited, and in the semisolid state, the fluidity is slightly enhanced. After that, the viscosity rises again and goes to solidification.

In the present invention, the layer (2) contains a phosphor, plays the role of converting the wavelength of light emitted from the LED element into a required wavelength, and covers, protects and seals the element. Layer (1) serves to increase the protection of the device. Layer (1) is transparent or translucent. In the present application, “transparent or translucent” means that the light transmittance is 80% or more in a visible light region of at least a wavelength of 400 to 500 nm, preferably 400 to 600 nm, more preferably 400 to 800 nm. Means. Here, the light transmittance is the ratio I / I ₀ (%) of the transmitted light intensity to the incident light intensity of light of a specific wavelength on a sample sheet having a thickness of 100 μm (where I ₀ is the intensity of the incident light). , I is the intensity of transmitted light).

  The layer (1) preferably has a thickness of 20 to 100 μm, more preferably 30 to 80 μm, in terms of obtaining good wavelength conversion performance. Since it depends on the particle diameter and dispersion concentration of the phosphor, it is desirable to select a thickness in consideration of them. When there is too much quantity of fluorescent substance, it will become difficult to obtain white light from blue LED, for example. Moreover, it is better not to be too thin for the forming operation in order to obtain a constant thickness in which the phosphors are uniformly dispersed. The thickness of the layer (2) is preferably 20 to 500 μm and more preferably 50 to 500 μm in terms of device protection.

  In the following description, the composition used for the layer (1) may be referred to as the composition (1), and the composition used for the layer (2) may be referred to as the composition (2). Me represents a methyl group, Et represents an ethyl group, Ph represents a phenyl group, and Vi represents a vinyl group.

  First, the components used in the preferred embodiment for the composition (1) and the composition (2) will be described. The description of the components common to the composition (1) and the composition (2) applies to the compositions (1) and (2) unless otherwise specified.

-(A) Resin-structured alkenyl group-containing organopolysiloxane-
An organopolysiloxane having a resin structure (that is, a three-dimensional network structure) which is an important component (A) of the composition of the present invention is composed of R ¹ SiO _1.5 units, R ² ₂ SiO units, and R ³ _a R ⁴ _b SiO _{( 4-ab) / 2} units (wherein R ¹ , R ² , and R ³ represent a methyl group, an ethyl group, a propyl group, a cyclohexyl group, or a phenyl group, and R ⁴ represents a vinyl group or an allyl group. A is 0, 1 or 2, b is 1 or 2, and a + b is 2 or 3.
At least a part of the R ² ₂ SiO unit is continuously repeated, and the number of repetitions is 5 to 300, preferably 10 to 300, more preferably 15 to 200, still more preferably 20 to 100. It is an organopolysiloxane having a resin structure partially containing a certain structure.

The structure in which at least a part of the R ² ₂ SiO unit is continuously repeated and the number of repetitions is 5 to 300 is the general formula (1):

(Where m is an integer from 5 to 300)
The linear diorganopolysiloxane chain structure represented by these is meant.
(A) At least a part of the entire R ² ₂ SiO unit present in the organopolysiloxane of the component, preferably 50 mol% or more (50 to 100 mol%), particularly 80 mol% or more (80 to 100 mol%). However, it is preferable to form a chain structure represented by the general formula (1) in the molecule.

In the molecule of component (A), the R ² ₂ SiO unit functions to stretch the polymer molecule in a straight line, and the R ¹ SiO _1.5 unit causes the polymer molecule to be branched or three-dimensionally networked. R ⁴ (vinyl group or allyl group) in the R ³ _a R ⁴ _b SiO _{(4-ab) / 2} unit is R ³ _c H _d SiO _{(4-cd) / 2 contained in the} component (B) described later. It plays a role of curing the composition of the present invention by hydrosilylation addition reaction with a hydrogen atom (ie, SiH group) bonded to the silicon atom of the unit.

The molar ratio of the three essential siloxane units constituting the component (A), that is, the molar ratio of R ¹ SiO _1.5 unit: R ² ₂ SiO unit: R ³ _a R ⁴ _b SiO _{(4-ab) / 2} unit is 90 to 24:75 to 9:50 to 1, particularly 70 to 28:70 to 20:10 to 2 (provided that the total is 100), which is preferable in terms of the properties of the cured product.

In the organopolysiloxane, R ³ _a R ⁴ _b SiO _{(4-ab) / 2} units are preferably present in a total of 0.001 mol / 100 g or more of vinyl groups and allyl groups, and 0.025 mol / 100 g or more. Is more preferable, and it is still more preferable that it is 0.03-0.3 mol / 100g.

  When the weight average molecular weight in terms of polystyrene by gel permeation chromatography (GPC) of this component (A) is in the range of 3,000 to 1,000,000, particularly 10,000 to 100,000, the polymer It is solid or semi-solid and is suitable from the viewpoint of workability and curability.

  Organopolysiloxane with such a resin structure is a combination of compounds that are raw materials for each unit such that the three siloxane units in the resulting polymer have the required molar ratio, for example, cohydrolytic condensation in the presence of an acid. Can be synthesized.

Here, as raw materials for R ¹ SiO _1.5 unit, chlorosilanes such as MeSiCl ₃ , EtSiCl ₃ , PhSiCl ₃ , propyltrichlorosilane, and cyclohexyltrichlorosilane, and alkoxysilanes such as methoxysilane corresponding to each of these chlorosilanes Etc. can be illustrated.

As a raw material of the R ² ₂ SiO unit,
ClMe ₂ SiO (Me ₂ SiO) _n SiMe ₂ Cl,
ClMe ₂ SiO (Me ₂ SiO) _m (PhMeSiO) _n SiMe ₂ Cl,
ClMe ₂ SiO (Me ₂ SiO) _m (Ph ₂ SiO) _n SiMe ₂ Cl,
HOMe ₂ SiO (Me ₂ SiO) _n SiMe ₂ OH,
HOMe ₂ SiO (Me ₂ SiO) _m (PhMeSiO) _n SiMe ₂ OH,
HOMe ₂ SiO (Me ₂ SiO) _m (Ph ₂ SiO) _n SiMe ₂ OH,
MeOMe ₂ SiO (Me ₂ SiO) _n SiMe ₂ OMe,
MeOMe ₂ SiO (Me ₂ SiO) _m (PhMeSiO) _n SiMe ₂ OMe,
MeOMe ₂ SiO (Me ₂ SiO) _m (Ph ₂ SiO) _n SiMe ₂ OMe
(Where m = an integer of 5 to 150 (average value), n = an integer of 5 to 300 (average value))
Etc. can be illustrated.

R ³ _a R ⁴ _b SiO _{(4-ab) / 2} units are R ³ R ⁴ SiO units, R ³ ₂ R ⁴ SiO _0.5 units, R ⁴ ₂ SiO units, and R ³ R ⁴ ₂ SiO _0.5 units. 1 type of siloxane units selected from or a combination of 2 or more types of siloxane units. Examples of the raw material include chlorosilanes such as Me ₂ ViSiCl, MeViSiCl ₂ , Ph ₂ ViSiCl, and PhViSiCl ₂ , and alkoxysilanes such as methoxysilane corresponding to each of these chlorosilanes.

In the present invention, the organopolysiloxane of component (A) is “consisting essentially of R ¹ SiO _1.5 units, R ² ₂ SiO units, and R ³ _a R ⁴ _b SiO _{(4-ab) / 2} units”. Is 90 mol% or more (90 to 100 mol%), particularly 95 mol% or more (95 to 100 mol%) of the siloxane units constituting the component (A), It means that 10 mol%, especially 0 to 5 mol% may be other siloxane units. Specifically, when the organopolysiloxane of component (A) is produced by co-hydrolysis and condensation of the above raw material compounds, R ¹ SiO _1.5 units, R ² ₂ SiO units and / or R ³ _a R ⁴ _{b In addition to} SiO 2 _{(4-ab) / 2} units, siloxane units having silanol groups may be by-produced. The organopolysiloxane of the component (A) is usually 10 mol% or less (0 to 10 mol%), preferably 5 mol% or less (0 to 5 mol%) of the silanol group-containing siloxane unit with respect to all siloxane units. ) May be contained. Examples of the silanol group-containing siloxane units include R ¹ (HO) SiO units, R ¹ (HO) ₂ SiO _0.5 units, R ² ₂ (HO) SiO _0.5 units, R ³ _a R ⁴ _b (HO) SiO _{( 3-ab) / 2} units, R ³ _a R ⁴ _b (HO) ₂ SiO _{(2-ab) / 2} units (wherein R ^{1 to} R ⁴ , a and b are as defined above). .

-(B) Organohydrogenpolysiloxane with resin structure-
The organohydrogenpolysiloxane having a resin structure (that is, a three-dimensional network structure) which is an important component (B) of the composition of the present invention is substantially composed of R ¹ SiO _1.5 units, R ² ₂ SiO units, and R ³ _c. It consists of H _d SiO _{(4-cd) / 2} units (where R ¹ , R ² , R ³ are as described above, c is 0, 1 or 2, d is 1 or 2, and c + d Is 2 or 3),
At least a part of the R ² ₂ SiO unit is continuously repeated, and the number of repetitions is 5 to 300, preferably 10 to 300, more preferably 15 to 200, still more preferably 20 to 100. It is an organohydrogenpolysiloxane having a resin structure partially containing a certain linear siloxane structure.

The structure in which at least a part of the R ² ₂ SiO unit is continuously repeated and the number of repetitions is 5 to 300 is present in the component (B) as described above with respect to the component (A). At least a part of the R ² ₂ SiO units, preferably 50 mol% or more (50 to 100 mol%), particularly 80 mol% or more (80 to 100 mol%), It means that a linear diorganopolysiloxane chain structure represented by the formula (1) is formed.

Also in the molecule of the component (B), the R ² ₂ SiO unit functions to extend the polymer molecule in a straight line, and the R ¹ SiO _1.5 unit causes the polymer molecule to be branched or three-dimensional networked. The hydrogen atom bonded to silicon in the R ³ _c H _d SiO _{(4-cd) / 2} unit reacts with the alkenyl group of the component (A) to cure the composition of the present invention. To play a role.

The molar ratio of the three essential siloxane units constituting the component (B), that is, the molar ratio of R ¹ SiO _1.5 unit: R ² ₂ SiO unit: R ³ _c H _d SiO _{(4-cd) / 2} unit is 90 to 24:75 to 9:50 to 1, particularly 70 to 28:70 to 20:10 to 2 (however, a total of 100) is preferable in terms of the properties of the cured product.

  In addition, the weight average molecular weight in terms of polystyrene by GPC of the component (B) is in the range of 3,000 to 1,000,000, particularly 10,000 to 100,000, such as workability and cured product characteristics. To preferred.

  Organohydrogenpolysiloxane with such a resin structure is synthesized by combining the raw materials of each unit so that the above three siloxane units have the required molar ratio in the resulting polymer and performing cohydrolysis. can do.

Here, examples of the raw material of the R ¹ SiO _1.5 unit include MeSiCl ₃ , EtSiCl ₃ , PhSiCl ₃ , propyltrichlorosilane, cyclohexyltrichlorosilane, and alkoxysilanes such as methoxysilane corresponding to each chlorosilane.

As a raw material of the R ² ₂ SiO unit,
ClMe ₂ SiO (Me ₂ SiO) _n SiMe ₂ Cl,
ClMe ₂ SiO (Me ₂ SiO) _m (PhMeSiO) _n SiMe ₂ Cl,
ClMe ₂ SiO (Me ₂ SiO) _m (Ph ₂ SiO) _n SiMe ₂ Cl,
HOMe ₂ SiO (Me ₂ SiO) _n SiMe ₂ OH,
HOMe ₂ SiO (Me ₂ SiO) _m (PhMeSiO) _n SiMe ₂ OH,
HOMe ₂ SiO (Me ₂ SiO) _m (Ph ₂ SiO) _n SiMe ₂ OH,
MeOMe ₂ SiO (Me ₂ SiO) _n SiMe ₂ OMe,
MeOMe ₂ SiO (Me ₂ SiO) _m (PhMeSiO) _n SiMe ₂ OMe,
MeOMe ₂ SiO (Me ₂ SiO) _m (Ph ₂ SiO) _n SiMe ₂ OMe
(Where m = an integer of 5 to 150 (average value), n = an integer of 5 to 300 (average value))
Etc. can be illustrated.

The R ³ _c H _d SiO _{(4-cd) / 2} unit is one or two selected from R ³ HSiO units, R ³ ₂ HSiO _0.5 units, H ₂ SiO units, and R ³ H ₂ SiO _0.5 units. It shows that it is an arbitrary combination of the above siloxane units, and as a raw material thereof, alkoxy such as methoxysilanes corresponding to these chlorosilanes, such as chlorosilanes such as Me ₂ HSiCl, MeHSiCl ₂ , Ph ₂ HSiCl, and PhHSiCl ₂ Silanes etc. can be illustrated.

In the present invention, the organohydrogenpolysiloxane of the component (B) consists essentially of “R ¹ SiO _1.5 units, R ² ₂ SiO units, and R ³ _c H _d SiO _{(4-cd) / 2} units. ”Means that 90 mol% or more (90 to 100 mol%), particularly 95 mol% or more (95 to 100 mol%) of the siloxane units constituting the component (B) are these three types of siloxane units, It means that -10 mol%, especially 0-5 mol% may be other siloxane units. Specifically, when the organopolysiloxane of component (B) is produced by co-hydrolysis and condensation of the above raw material compounds, R ¹ SiO _1.5 units, R ² ₂ SiO units, and R ³ _c H _d SiO _{In addition to (4-cd) / 2} units, siloxane units having silanol groups may be by-produced. The organopolysiloxane of component (B) is usually 10 mol% or less (0 to 10 mol%), preferably 5 mol% or less (0 to 5 mol%) of the silanol group-containing siloxane unit with respect to all siloxane units. ) May be contained. Examples of the silanol group-containing siloxane units include R ¹ (HO) SiO units, R ¹ (HO) ₂ SiO _0.5 units, R ² ₂ (HO) SiO _0.5 units, R ³ _c H _d (HO) SiO _{(3 -cd) / 2} units, R ³ _c H _d (HO) ₂ SiO _{(2-cd) / 2} units (wherein R ^{1 to} R ³ , c and d are as described above).

  The blending amount of the organohydrogenpolysiloxane of component (B) is the molar ratio of hydrogen atoms (SiH groups) bonded to silicon atoms in component (B) relative to the total amount of vinyl groups and allyl groups in component (A). The amount is 0.1 to 4.0, particularly preferably 0.5 to 3.0, and more preferably 0.8 to 2.0. If it is less than 0.1, the curing reaction does not proceed and it is difficult to obtain a silicone cured product. If it exceeds 4.0, a large amount of unreacted SiH groups remain in the cured product. Causes changes over time.

-(C) Platinum group metal catalyst-
This catalyst component is blended in order to promote the addition curing reaction of the composition of the present invention, and there are platinum-based, palladium-based and rhodium-based ones. From the viewpoint of cost, platinum-based materials such as platinum, platinum black, chloroplatinic acid, for example, H ₂ PtCl ₆ · mH ₂ O, K ₂ PtCl ₆ , KHPtCl ₆ · mH ₂ O, K ₂ PtCl ₄ , K ₂ Examples include PtCl ₄ · mH ₂ O, PtO ₂ · mH ₂ O, (where m is a positive integer), and complexes thereof with hydrocarbons such as olefins, alcohols, or vinyl group-containing organopolysiloxanes. Can do. These catalysts can be used singly or in combination of two or more.

  The compounding amount of the component (C) may be an effective amount for curing, and is usually 0.1 to 500 ppm in terms of mass as a platinum group metal with respect to the total amount of the components (A) and (B), particularly preferably. Is used in the range of 0.5 to 100 ppm.

-(D) phosphor-
The phosphor of the component (D) may be any phosphor as long as it is a known phosphor, and the blending amount thereof is (A) to (A) in the composition (2) constituting the phosphor-containing layer (2). C) 0.1-300 mass parts is preferable normally with respect to 100 mass parts of total of a component, and the range of 10-300 is more preferable. The average particle diameter of the phosphor of component (D) can be determined as a mass average value D ₅₀ (or median diameter) in particle size distribution measurement by laser light diffraction. In general, the average particle diameter may be 10 nm or more, preferably 10 nm to 10 μm, more preferably about 10 nm to 1 μm.

  The fluorescent substance may be any substance that absorbs light from a semiconductor light emitting diode having a nitride semiconductor as a light emitting layer and converts the light to light of a different wavelength. For example, it is mainly activated by nitride-based phosphors and oxynitride-based phosphors such as Eu and Ce, lanthanoid-based phosphors such as Eu, and transition metal-based elements such as Mn. Alkaline earth metal halogen apatite phosphor, Alkaline earth metal halogen borate phosphor, Alkaline earth metal aluminate phosphor, Alkaline earth metal silicate phosphor, Alkaline earth metal sulfide phosphor, Alkaline earth Metal thiogallate phosphors, alkaline earth metal silicon nitride phosphors, germanate phosphors, rare earth aluminate phosphors, rare earth silicate phosphors or Eu activated mainly with lanthanoid elements such as Ce At least selected from organic and organic complex phosphors activated mainly by lanthanoid elements such as Ca-Al-Si-ON-oxynitride glass phosphors, etc. It is preferably any one or more. As specific examples, the following phosphors can be used, but are not limited thereto. In the following, M is at least one element selected from Sr, Ca, Ba, Mg, and Zn, X is at least one element selected from F, Cl, Br, and I, and R is Eu, Mn, or Any combination of Eu and Mn.

Nitride-based phosphors mainly activated by lanthanoid elements such as Eu and Ce include M ₂ Si ₅ N ₈ : Eu. In addition to M ₂ Si ₅ N ₈ : Eu, MSi ₇ N ₁₀ : Eu, M _1.8 Si ₅ O _0.2 N ₈ : Eu, M _0.9 Si ₇ O _0.1 N ₁₀ : Eu, etc. is there.

An oxynitride phosphor mainly activated by a lanthanoid element such as Eu or Ce includes MSi ₂ O ₂ N ₂ : Eu.

An alkaline earth metal halogen apatite phosphor mainly activated by a lanthanoid-based element such as Eu or a transition metal-based element such as Mn includes M ₅ (PO ₄ ) ₃ X: R.

In the alkaline earth metal borate phosphor, M ₂ B ₅ O ₉ X: R (M is at least one selected from Sr, Ca, Ba, Mg, Zn. X is F, Cl, And at least one selected from Br and I. R is Eu, Mn, or any one of Eu and Mn.).

Alkaline earth metal aluminate phosphors include SrAl ₂ O ₄ : R, Sr ₄ Al ₁₄ O ₂₅ : R, CaAl ₂ O ₄ : R, BaMg ₂ Al ₁₆ O ₂₇ : R, BaMg ₂ Al ₁₆ O ₁₂ : R, BaMgAl ₁₀ O ₁₇ : R (R is one or more of Eu, Mn, Eu and Mn).

Examples of the alkaline earth metal sulfide phosphor include La ₂ O ₂ S: Eu, Y ₂ O ₂ S: Eu, and Gd ₂ O ₂ S: Eu.

Examples of rare earth aluminate phosphors mainly activated with lanthanoid elements such as Ce include Y ₃ Al ₅ O ₁₂ : Ce, (Y _0.8 Gd _0.2 ) ₃ Al ₅ O ₁₂ : Ce, Y _{3 (Al 0.8 Ga 0.2) 5 O} 12: Ce, and the like (Y, Gd) 3 (Al , Ga) YAG -based phosphor represented by the composition formula of _{5 O 12.} Further, there are Tb ₃ Al ₅ O ₁₂ : Ce, Lu ₃ Al ₅ O ₁₂ : Ce, etc. in which a part or all of Y is substituted with Tb, Lu or the like.

Other phosphors include ZnS: Eu, Zn ₂ GeO ₄ : Mn, MGa ₂ S ₄ : Eu, and the like.

  The phosphor described above contains at least one selected from Tb, Cu, Ag, Au, Cr, Nd, Dy, Co, Ni, and Ti instead of Eu or in addition to Eu as desired. You can also.

The Ca—Al—Si—O—N-based oxynitride glass phosphor is expressed in terms of mol%, CaCO ₃ is converted to CaO, 20 to 50 mol%, Al ₂ O ₃ is 0 to 30 mol%, SiO 25 to 60 mol%, AlN 5 to 50 mol%, rare earth oxide or transition metal oxide 0.1 to 20 mol%, and oxynitride glass having a total of 5 components of 100 mol% as a base material This is a phosphor. In the phosphor using oxynitride glass as a base material, the nitrogen content is preferably 15% by mass or less. In addition to the rare earth oxide ion, another rare earth element ion serving as a sensitizer is added to the rare earth oxide. It is preferable to contain as a co-activator in content in the range of 0.1-10 mol% in fluorescent glass.

  Moreover, it is fluorescent substance other than the said fluorescent substance, Comprising: The fluorescent substance which has the same performance and effect can also be used.

-Other ingredients-
In the composition of the present invention, various additives known per se can be blended as necessary, in addition to the above-described components.
・ Inorganic filler:
The inorganic filler may be added for the purpose of reducing the thermal expansion coefficient of the layer (1) and / or the layer (2). Examples of inorganic fillers include reinforcing inorganic fillers such as fumed silica, fumed titanium dioxide, and fumed alumina, fused silica, alumina, calcium carbonate, calcium silicate, titanium dioxide, ferric oxide, and zinc oxide. And non-reinforcing inorganic fillers. These inorganic fillers in total are in the range of 100 parts by mass or less (0 to 100 parts by mass) per 100 parts by mass of the total amount of the components (A) and (B), and do not impair the objects and effects of the present invention. It can mix | blend suitably in the range.

・ Adhesion aid:
Moreover, in order to provide adhesiveness to the composition of this invention, an adhesion assistant can be added as needed. Examples of the adhesion assistant include a hydrogen atom (SiH group) bonded to a silicon atom in one molecule, an alkenyl group (for example, Si—CH═CH ₂ group) bonded to a silicon atom, and an alkoxysilyl group (for example, trimethoxysilyl). Group) and an epoxy group (for example, glycidoxypropyl group, 3,4-epoxycyclohexylethyl group) a linear or cyclic silicon atom containing at least two, preferably two or three functional groups 4 to 50, preferably about 4 to 20 organosiloxane oligomers, organooxysilyl-modified isocyanurate compound represented by the following general formula (2) and / or hydrolysis condensate thereof (organosiloxane-modified isocyanurate compound) Etc.

[Wherein R ¹⁹ represents the following formula (3)

(Here, R ²⁰ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, and s is an integer of 1 to 6, particularly 1 to 4.)
Or a monovalent hydrocarbon group containing an aliphatic unsaturated bond, at least one of R ¹⁹ is an organic group of the formula (3). ]

Examples of the monovalent hydrocarbon group containing an aliphatic unsaturated bond represented by R ¹⁹ in the general formula (2) include a vinyl group, an allyl group, a propenyl group, an isopropenyl group, a butenyl group, an isobutenyl group, a pentenyl group, and a hexenyl group. And a cycloalkenyl group having 6 to 8 carbon atoms, such as an alkenyl group having 2 to 6 carbon atoms, particularly a cyclohexenyl group, and the like. Examples of the monovalent hydrocarbon group for R ²⁰ in the formula (3) include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a hexyl group, and a cyclohexyl group. alkyl group such as, exemplified alkenyl and cycloalkenyl groups for the above R ^19, further monovalent hydrocarbon group having 1 to 8 carbon atoms, particularly 1 to 6 such as an aryl group such as a phenyl group and the like, preferably Is an alkyl group.

  Further, as adhesion assistants, 1,5-glycidoxypropyl-1,3,5,7-tetramethylcyclotetrasiloxane, 1-glycidoxypropyl-5-trimethoxysilylethyl-1,3,5 , 7-tetramethylcyclotetrasiloxane, and the compounds represented by the following formulas are exemplified.

(In the formula, g and h are each a positive integer in the range of 0 to 50, and g + h satisfies 2 to 50, preferably 4 to 20.)

  Among the above-mentioned organosilicon compounds, compounds having particularly good adhesion to the resulting cured product have a silicon atom-bonded alkoxy group and an alkenyl group or silicon atom-bonded hydrogen atom (SiH group) in one molecule. It is an organosilicon compound.

  The compounding amount of the adhesion assistant is usually 10 parts by mass or less (that is, 0 to 10 parts by mass), preferably 0.1 to 8 parts by mass, more preferably 0.2 to 100 parts by mass of the component (A). About 5 parts by mass can be blended. If the amount is too large, the hardness of the cured product may be adversely affected and surface tackiness may be increased.

  Further, if necessary, a liquid silicone component can be added to such an extent that the thermosetting silicone resin sheet of the present invention maintains a solid or semi-solid at room temperature and does not become liquid. As such a liquid silicone component, those having a viscosity of about 1 to 100,000 mPa · s at normal temperature (25 ° C.) are preferable, and examples thereof include vinyl siloxane, hydrogen siloxane, alkoxy siloxane, hydroxy siloxane, and mixtures thereof. The addition amount is a condition that the silicone composition sheet maintains a solid or semi-solid at room temperature, and is usually 50% by mass or less based on the entire silicone composition sheet.

・ Reaction inhibitors:
A reaction inhibitor can be appropriately added to the composition of the present invention as necessary. The reaction inhibitor is added for the purpose of suppressing the curing reaction due to hydrosilylation and improving the storage stability. Examples of the reaction inhibitor include high vinyl group-containing organopolysiloxanes such as tetramethyltetravinylcyclotetrasiloxane, triallyl isocyanurate, alkyl maleate, acetylene alcohols and their silane-modified products and siloxane-modified products, Examples thereof include compounds selected from the group consisting of peroxide, tetramethylethylenediamine, benzotriazole, and mixtures thereof. The reaction inhibitor is usually added in an amount of 0.001 to 1.0 part by mass, preferably 0.005 to 0.5 part by mass, per 100 parts by mass of the component (A).

  As a typical example of the composition of the present invention, a phosphor-containing silicone resin sheet consisting essentially of components (A) to (D) and a transparent or translucent silicone consisting essentially of components (A) to (C) A two-layer silicone resin sheet on which a resin sheet is bonded may be mentioned.

-Preparation and curing conditions-
The composition (2) used for the production of the silicone resin sheet of the present invention includes the components (A) to (D) and optional components blended as necessary, or the composition (1) comprises (A) to ( C) A silicone resin composition containing or not containing a phosphor is prepared by uniformly mixing the component and optional components blended as necessary. Usually, the two liquids are stored so that the curing does not proceed, and the two liquids are mixed at the time of use and transferred to the next step. Of course, a small amount of a reaction inhibitor such as acetylene alcohol described above can be added and used as one liquid.

In order to produce the two-layer laminated silicone resin sheet of the present invention, the phosphor-containing silicone resin composition (2) and the transparent thermosetting silicone resin composition (1) containing no phosphor are individually separated on a release film. Then, it is processed into a sheet with a film coater or hot press.
Usually, the phosphor-containing silicone resin composition is processed into a sheet shape with a film coater or the like, preferably with a sheet thickness of 20 to 100 μm.

  On the other hand, the transparent silicone resin composition (1) containing no phosphor is processed into a sheet by the same method, but the thickness of the sheet is preferably 20 to 500 μm. If it is too thin, the gold wire that electrically connects the element and the element to the lead cannot be protected from external force. As the protective layer, a thickness of 500 μm is sufficient, and if it is too thick, no further effect can be expected, which is not desirable from the viewpoint of cost.

  Here, a two-layer silicone resin sheet having release films on the upper and lower surfaces can be produced by bonding two types of individually molded silicone resin sheets with a thermal laminator or a hot press. As another method, a phosphor-containing silicone resin composition (2) is first used to form a film, and then a phosphor-free transparent thermosetting silicone resin composition is spray-coated again on the film coater or hot press. Can be processed into a sheet with a machine. The produced two-layer silicone resin sheet is usually frozen and stored.

  The following method is illustrated as a method of sealing an LED element using the two-layered thermosetting silicone resin sheet obtained here.

  For example, FIG. 2 (A is a cross-sectional view conceptually showing a state in which the sheet 11 of the present invention is being applied to the ceramic substrate 5 on which the LED element 3 is mounted, and B is a cross-sectional view conceptually showing the attached state. After the blue LED 3 is bonded to the ceramic substrate 5 having an external connection terminal (not shown) as shown by a resin die bond material, the external connection terminal and the LED element 3 are connected using the gold wire 4. To do. In order to seal this type of LED device, the two-layer silicone resin sheet of the present invention is stuck so that the entire LED mounting substrate can be covered, and heated to cure and seal the entire LED element.

  Although the silicone resin sheet 11 of the present invention is cured by heating, it softens once during the curing process, and then increases in viscosity and solidifies, and therefore damages the gold wire 4 even if it is applied on the gold wire 4. It can seal without. Usually, the substrate 5 on which a plurality of LEDs 3 sealed in this manner are mounted is coated with a silicone resin sheet, cured and sealed, and then diced into individual pieces. An LED device in which the connection with the external terminal is joined by a gold bump or the like instead of the gold wire can be sealed in the same manner in the case of the gold wire connection.

Further, in the case of the LED element mounted in the reflector 6, FIG. 3 (A is a cross-sectional view conceptually showing a state in which the sheet 11 of the present invention is to be attached to the external lead 7 mounted with the LED element 3, (B is a cross-sectional view conceptually showing the state of being affixed.) As shown in FIG. 2, the two-layer silicone resin sheet 11 is affixed so that the gold wire 4 connecting the LED element 3 and the external lead 7 is covered. Then, it is heated and cured and sealed.
In addition, since the transparent silicone protective layer can be cured at the same time, there is no color shift compared to a conventional method in which a silicone resin for casting containing a phosphor is poured and the phosphor is allowed to settle and cure. Can be produced well.

  The cured silicone resin forms a flexible cured product with high hardness and no surface tack, and consists of a silicone resin layer containing a phosphor and a transparent silicone resin layer. And can be converted into uniform white light.

  When the substrate and the LED element are bonded in a flip-chip format, as shown in FIG. 4, after the LED element 3 and the external lead 7 are bonded in advance with a gold bump 9 or the like, a silicon resin or an epoxy resin containing silica or the like is used. The underfill material 8 is injected and cured to protect the bumps 9 and the elements 3. Then, the silicone resin sheet 11 which consists of two layers is stuck, and a sheet | seat is hardened by heating. The hue and sealing shape can be controlled by the thickness of the silicone resin layer 2 containing the phosphor and the transparent silicone resin layer 1.

  The pressure-bonding of the two-layer silicone resin sheet onto the LED element can be usually performed at room temperature to 300 ° C. under a pressure of 10 MPa or less (usually 0.01 to 10 MPa), preferably 5 MPa or less (for example, 0.1-5 MPa), in particular 0.5-5 MPa.

  Since the two-layer silicone resin sheet of the present invention is made of an A-stage (unreacted) silicone resin as described above, it is easily softened at the above temperature and then solidified. Therefore, an LED connected by a gold wire can be sealed without deforming the gold wire.

  When the viscosity at the time of heating becomes too low in the A stage (unreacted state), the reaction can proceed by leaving it in advance in a temperature atmosphere of 50 ° C. to 100 ° C. until the desired viscosity is reached. This is a content that can be freely selected within the scope of the present invention.

  The silicone resin compositions (2) and (1) forming the two layers are most preferably the same type of composition. When the compositions (2) and (1) are not the same composition, the difference in softening temperature between the respective resin compositions is preferably within 10 ° C., more preferably within 5 ° C. However, even if the softening temperature is greatly deviated, there may be no problem depending on the structure of the LED. Here, the “softening temperature” is a temperature at which the resin softens, and there are various methods. In the present invention, an apparatus such as SS6100 manufactured by SII is used, and thermomechanical analysis (TMA) is used for penetration. This means the softening temperature measured by the method (a method of measuring the process in which the needle is buried in the resin and measuring the softening temperature from the deformation of the sample). The softening temperature of the silicone resin compositions (2) and (1) is usually 35 to 100 ° C, preferably 40 to 80 ° C.

  Curing is usually 50-200 ° C., in particular 70-180 ° C., for 1-30 minutes, in particular 2-10 minutes. Further, post-curing can be performed at 50 to 200 ° C., particularly 70 to 180 ° C. for 0.1 to 10 hours, particularly 1 to 4 hours.

  EXAMPLES Hereinafter, although a synthesis example, a preparation example, an Example, and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example. In the following examples, the viscosity is a value of 25 ° C. The weight average molecular weight is a polystyrene equivalent value measured by gel permeation chromatography (GPC).

[Synthesis Example 1]
-Vinyl group-containing organopolysiloxane resin (A1)-
Organosilane represented by PhSiCl ₃ : 27 mol, ClMe ₂ SiO (Me ₂ SiO) ₃₃ SiMe ₂ Cl: 1 mol, MeViSiCl ₂ : 3 mol was dissolved in toluene solvent, dropped into water, co-hydrolyzed, further washed with water, alkali After neutralization and dehydration by washing, the solvent was stripped to synthesize a vinyl group-containing resin (A1). This resin has a constitutional ratio of a siloxane unit and a structure represented by [—SiMe ₂ O— (Me ₂ SiO) ₃₃ —SiMe ₂ O _2/2 ] represented by the formula: [PhSiO _3/2 ] _0.27 [ -SiMe ₂ O- (Me ₂ SiO) ₃₃ -SiMe ₂ O _2/2 ] _0.01 [MeViSiO _2/2 ] _0.03 . This resin had a weight average molecular weight of 62,000 and a melting point of 60 ° C.

[Synthesis Example 2]
-Hydrosilyl group-containing organopolysiloxane resin (B1)-
Organosilane represented by PhSiCl ₃ : 27 mol, ClMe ₂ SiO (Me ₂ SiO) ₃₃ SiMe ₂ Cl: 1 mol, MeHSiCl ₂ : 3 mol were dissolved in toluene solvent, dropped into water, co-hydrolyzed, further washed with water, alkali After neutralization and dehydration by washing, the solvent was stripped to synthesize a hydrosilyl group-containing resin (B1). This resin has a constitutional ratio of a siloxane unit and a structure represented by [—SiMe ₂ O— (Me ₂ SiO) ₃₃ —SiMe ₂ O _2/2 ] represented by the formula: [PhSiO _3/2 ] _0.27 [ -SiMe ₂ O- (Me ₂ SiO) ₃₃ -SiMe ₂ O _2/2 ] _0.01 [MeViSiO _2/2 ] _0.03 . This resin had a weight average molecular weight of 58,000 and a melting point of 58 ° C.

[Synthesis Example 3]
-Vinyl group-containing organopolysiloxane resin (A2)-
Organosilane represented by PhSiCl ₃ : 27 mol, ClMe ₂ SiO (Me ₂ SiO) ₃₃ SiMe ₂ Cl: 1 mol, Me ₂ ViSiCl: 3 mol dissolved in toluene solvent, dropped into water, cohydrolyzed, further washed with water, After neutralization and dehydration by alkali washing, the solvent was stripped to synthesize a vinyl group-containing resin (A2). This resin has a constitutional ratio of a siloxane unit and a structure represented by [—SiMe ₂ O— (Me ₂ SiO) ₃₃ —SiMe ₂ O _2/2 ] represented by the formula: [PhSiO _3/2 ] _0.27 [ -SiMe ₂ O- (Me ₂ SiO) ₃₃ -SiMe ₂ O _2/2 ] _0.01 [Me ₂ ViSiO _1/2 ] _0.03 . This resin had a weight average molecular weight of 63,000 and a melting point of 63 ° C.

[Synthesis Example 4]
-Hydrosilyl group-containing organopolysiloxane resin (B2)-
Organosilane represented by PhSiCl ₃ : 27 mol, ClMe ₂ SiO (Me ₂ SiO) ₃₃ SiMe ₂ Cl: 1 mol, Me ₂ HSiCl: 3 mol dissolved in toluene solvent, dropped into water, cohydrolyzed, further washed with water, After neutralization and dehydration by alkali washing, the solvent was stripped to synthesize a hydrosilyl group-containing resin (B2). This resin has a constitutional ratio of a siloxane unit and a structure represented by [—SiMe ₂ O— (Me ₂ SiO) ₃₃ —SiMe ₂ O _2/2 ] represented by the formula: [PhSiO _3/2 ] _0.27 [ -SiMe ₂ O- (Me ₂ SiO) ₃₃ -SiMe ₂ O _2/2 ] _0.01 [Me ₂ HSiO _1/2 ] _0.03 . This resin had a weight average molecular weight of 57,000 and a melting point of 56 ° C.

[Preparation Example 1]
(Preparation example of composition (2))
Vinyl group-containing organopolysiloxane resin (A1) of Synthesis Example 1: 189 g, hydrosilyl group-containing organopolysiloxane resin (B1) of Synthesis Example 2: 189 g, acetylene alcohol-based ethynylcyclohexanol as a reaction inhibitor: 0.2 g, Octyl alcohol modified solution of chloroplatinic acid: 90 parts by mass of the base composition to which 0.1 g was added, and 10 parts by mass of a phosphor (YAG) having a particle size of 5 μm (average particle size) was added and heated to 60 ° C. The resulting mixture was thoroughly stirred with a planetary mixer to prepare a silicone resin composition (2). This composition (2) was a plastic solid at 25 ° C. It was 60 degreeC when the softening point of the obtained composition was measured by the penetration method by TMA [Use apparatus: SS6100 by SII company].

[Preparation Example 2]
(Preparation example of composition (1))
Vinyl group-containing organopolysiloxane resin (A1) of Synthesis Example 1: 189 g, hydrosilyl group-containing organopolysiloxane resin (B1) of Synthesis Example 2: 189 g, acetylene alcohol-based ethynylcyclohexanol as a reaction inhibitor: 0.2 g, Octyl alcohol-modified solution of chloroplatinic acid: The composition to which 0.1 g was added was thoroughly stirred with a planetary mixer heated to 60 ° C. to prepare a silicone resin composition (1). This composition (1) was a plastic solid at 25 ° C. It was 62 degreeC when the softening point of the obtained composition was measured like preparation example 1. FIG.

[Preparation Example 3]
Instead of the silicone resin composition prepared in Synthesis Example 1, the main component is a vinyl group-containing organopolysiloxane resin that does not contain a linear diorganopolysiloxane chain structure having 5 to 300 repeating units and is liquid at room temperature. A phosphor (YAG) having the same particle diameter of 5 μm (average particle diameter) as in Example 1 with respect to 90 parts by mass of KJR-632 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), which is a commercially available addition reaction curable silicone varnish. ) After adding 10 parts by mass, a well-stirred composition was produced with a planetary mixer heated to 60 ° C.

[Preparation Example 4]
Instead of the vinyl group-containing organopolysiloxane (A1) prepared in Synthesis Example 1, a vinyl group-containing organopolysiloxane that does not contain a linear diorganopolysiloxane chain structure having 5 to 300 repeating units and is liquid at room temperature The same particle size of 5 μm (average particle size) as in Example 1 with respect to 70 parts by mass of KJR-632L-1 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), which is a commercially available addition reaction curable silicone varnish mainly composed of resin. (Diameter) phosphor (YAG) 30 parts by mass was added, and then a well-stirred composition was produced with a planetary mixer heated to 60 ° C.

[Example 1]
(1) Production of phosphor-containing silicone resin sheet The composition (2) of Preparation Example 1 was sandwiched between two fluororesin-coated PET films (peeling films), and 5 t at 80 ° C. using a heat press. Compression molding was performed for 5 minutes under pressure to form a sheet having a thickness of 50 μm with PET films attached on both sides.

(2) Production of transparent silicone resin sheet The composition (1) of Preparation Example 2 was sandwiched between a PET film (pressurizing base film) and a fluororesin-coated PET film (peeling film), and a hot press was used. Then, compression molding was performed at 80 ° C. under a pressure of 5 t for 5 minutes to form a sheet having a thickness of 100 μm with the respective films attached to the two surfaces.

(3) Preparation of two-layer silicone resin sheet The release film on one side of the phosphor-containing silicone resin sheet prepared in (1) is peeled off, and the release film of the transparent silicone resin sheet prepared in (2) is peeled off. The resin exposed surfaces were put together and pressed together at a temperature of 40 ° C. using a bonding apparatus, and bonded together without any voids or gaps. As shown in FIG. 1, the obtained two-layer silicone resin sheet has a fluororesin-coated PET film 10b attached to the phosphor-containing silicone resin layer 2 side, and a PET film 10a attached to the transparent silicone resin layer 1 side. Is the sheet 11.

[Preparation Example 5]
(Preparation example of composition (2))
Vinyl group-containing resin (A2) of synthesis example 3: 189 g, hydrosilyl group-containing resin (B2) of synthesis example 4: 189 g, acetylene alcohol-based ethynylcyclohexanol as a reaction inhibitor: 0.2 g, octyl alcohol of chloroplatinic acid Denaturing solution: After adding 70 parts by mass of phosphor (YAG) having a particle size of 5 μm (average particle size) to 70 parts by mass of the base composition to which 0.1 g was added, these were heated to 60 ° C. The mixture was thoroughly stirred with a planetary mixer to prepare a silicone resin composition. This composition was a plastic solid at 25 ° C. When the softening point of the obtained composition was measured in the same manner as in Preparation Example 1, it was 65 ° C.

[Preparation Example 6]
(Preparation example of composition (1))
Vinyl group-containing resin (A2) of Synthesis Example 3: 189 g, Hydrosilyl group-containing resin of Synthesis Example 4 (B2): 189 g, acetylene alcohol-based ethynylcyclohexanol as a reaction inhibitor: 0.2 g, octyl alcohol of chloroplatinic acid Denaturing solution: The composition to which 0.1 g was added was thoroughly stirred with a planetary mixer heated to 60 ° C. to prepare a silicone resin composition. This composition was a plastic solid at 25 ° C. The softening point of the obtained composition was measured in the same manner as in Preparation Example 1 and found to be 63 ° C.

[Example 2]
(1) Production of phosphor-containing silicone resin sheet The composition of Preparation Example 5 was sandwiched between two fluororesin-coated PET films (peeling films), and was heated at 80 ° C. under a pressure of 5 t using a hot press machine. Compression molding was performed for 5 minutes to form a film having a thickness of 70 μm with PET films attached on both sides.

(2) Production of transparent silicone resin sheet The composition of Preparation Example 6 was sandwiched between a PET film (pressing base film) and a fluororesin-coated PET film (peeling film), and then heated at 80 ° C. using a hot press machine. Then, compression molding was performed for 5 minutes under a pressure of 5 t, and each sheet was molded into a sheet having a thickness of 125 μm with the respective films attached to the two surfaces.

(3) Preparation of two-layer silicone resin sheet Peel off one release film of the phosphor-containing silicone resin sheet prepared in (1) and the release film of the transparent silicone resin sheet prepared in (2), and resin exposure of each sheet The surfaces were combined, and bonded using a bonding apparatus (thermal lamination) at a temperature of 40 ° C. without voids or gaps. The obtained two-layer silicone resin sheet is a sheet in which a fluororesin-coated PET film on the phosphor-containing silicone resin side and a PET film on the transparent silicone resin side.

Example 3
(Ceramic substrate LED element sealing)
The two-layer thermosetting silicone resin sheet obtained in Example 1 was cut into chips with the release film as shown in FIG. After peeling the release film from one side of the obtained sheet piece, after placing it on the GaN-based LED element 3 so that the exposed phosphor-containing silicone resin surface is in contact with the LED chip, the release film is removed from the other side of the sheet piece. did. Next, when it heated at 150 degreeC for 5 minute (s), the silicone resin sheet once softened on the LED element, the whole element was coat | covered, and the fluorescent substance containing resin layer 2 and the transparent silicone resin layer 1 which were hardened were formed. Further, this was heated at 150 ° C. for 60 minutes to be secondarily cured. A light emitting semiconductor (LED) device having a flip chip structure coated with the phosphor-containing silicone resin layer 2 and the transparent silicone resin layer 1 thus obtained was produced. In the figure, 9 is a gold bump, and 8 is a silicone underfill material containing 60% by mass of silica. Three sample LEDs were prepared, each of which was made to emit light, and the chromaticity coordinates were measured with an LED optical property monitor (LE-3400) manufactured by Otsuka Electronics. The average value of the measured values for three was obtained.

Example 4
(Encapsulation of LED elements mounted in the reflector)
In order to seal the GaN-based LED element 3 mounted on the reflector 6 shown in FIG. 3 using the two-layer thermosetting silicone resin sheet obtained in Example 2, the entire release film is cut into a chip size. Small pieces. The LED element 3 was bonded and mounted in a reflector 6 with a silicone resin die bond material, and the LED element 3 and an external electrode (not shown) were connected by a gold wire 4.

  The release film is peeled off from one side of the obtained sheet piece 11 and placed on the GaN-based LED element 3 so that the exposed surface of the phosphor-containing silicone resin layer 2 is in contact with the LED chip 3. The release film was removed. Next, when heated at 150 ° C. for 5 minutes, the silicone resin sheet 11 was coated and cured on the LED element 3 as shown in FIG. 3B, and the phosphor-containing resin layer 2 and the transparent silicone resin were cured. Layer 1 was formed. Further, this was heated at 150 ° C. for 60 minutes to be secondarily cured. A reflector-mounted light-emitting semiconductor (LED) device coated with the phosphor-containing silicone resin layer 2 and the transparent silicone resin layer 1 thus obtained was produced (B in FIG. 3). Three sample LEDs were prepared, each of which was made to emit light, and the chromaticity coordinates were measured with an LED optical property monitor (LE-3400) manufactured by Otsuka Electronics. The average value of the measured values for three was obtained.

[Comparative Example 1]
A GaN-based LED element was bonded and mounted in the reflector 6 with a silicone resin die bond material, and the LED element 3 and the external electrode were joined with a gold wire 4. Next, the silicone resin composition produced in Preparation Example 4 is injected in such an amount that the entire reflector can be covered, and cured at 60 ° C. for 30 minutes, 120 ° C. for 1 hour, and further at 150 ° C. for 1 hour to produce a light emitting semiconductor device. did. Three sample LEDs were prepared, each of which was made to emit light, and the chromaticity coordinates were measured with an LED optical property monitor (LE-3400) manufactured by Otsuka Electronics. The average value of the measured values for three was obtained.

<Characteristic evaluation>
-Dispersibility of phosphor in two-layer silicone sheet The 10-cm square two-layer silicone sheet produced in Examples 1 and 2 was cured at 120 ° C for 30 minutes and 150 ° C for 1 hour, and then cut into 1-cm squares. The thickness of the phosphor layer on the cut surface of 100 pieces and the thickness of the transparent layer were measured with a microscope. As a result, in the case of the two-layer silicone sheet of Example 1, the thickness of the phosphor layer was 48 to 51 μm, the thickness of the transparent layer was 98 to 102 μm, and in the case of the sheet of Example 2, the phosphor layer was 67 to 71 μm and transparent. The layer thickness was controlled in the range of 122-126 μm.

-Adhesive strength between two-layer silicone sheets In order to measure the adhesive strength between two types of silicone-containing and non-containing phosphors that respectively form a phosphor layer and a transparent layer, the silicone sheets of Examples 1 and 2 were measured at 120 ° C. For 30 minutes at 150 ° C. for 1 hour. Thereafter, the phosphor layer and the transparent layer were tried to be peeled off, but they were completely adhered, and the phosphor layer and the transparent layer were agglomerated and broken.

-Dispersibility of the phosphor in the light emitting semiconductor device In order to confirm the dispersibility of the phosphor in the light emitting semiconductor device, 10 light emitting semiconductor devices mounted in the reflector manufactured in Example 4 and Comparative Example 1 were cut. And the thickness on the element of the fluorescent substance of a cross section was measured with the microscope. As a result, in the case of Example 4 using a two-layer silicone sheet, the phosphor was uniformly dispersed at 48 to 51 μm on the element, whereas in the case of Comparative Example 1, the sedimentation was insufficient and the upper part of the element was 100 μm. The phosphor was present at a certain level, and the density of the phosphor was higher as the distance from the device was closer. The dispersion state of the phosphor was not uniform.

-Measurement of chromaticity coordinates Three light emitting semiconductor devices prepared in Examples 3 and 4 and Comparative Example 1 were prepared, each of which was made to emit light, and the chromaticity coordinates were measured by an Otsuka Electronics LED optical characteristic monitor (LE-3400). Variation was measured. The average value of the measured values for three was obtained.
(Note: u ': CIE 1976 chromaticity coordinates. According to the method described in JIS Z8726.)

(*) JIS Z8729: L * u * v color system

  By using the two-layer silicone sheet of the present invention, a uniform light-emitting semiconductor device without color misregistration could be obtained.

[Reference Example 1]
(1) Production of transparent silicone resin sheet The composition of Preparation Example 2 was sandwiched between two release films, and compression-molded for 5 minutes at 80 ° C under a pressure of 5 t using a hot press machine. Each surface was molded into a sheet having a thickness of 100 μm.

Measurement of light transmittance The sample sheet having a thickness of 100 μm prepared in Reference Example 1 was laminated on a glass plate, and the light transmittance was measured using a spectrophotometer U-4100 (manufactured by Hitachi High-Tech), with a scanning speed of 200 nm / min, Measurement was performed in a scanning wavelength range of 300 nm to 800 nm. Table 2 shows the measurement results of light transmittance at 450 nm and 750 nm.

  From Table 2, it can be seen that the layer (2) of the sheet produced in Example 1 has high transparency.

  The thermosetting silicone resin sheet of the present invention is useful for coating and sealing light emitting elements such as LED elements, and for manufacturing light emitting devices.

1: Transparent silicone resin layer not containing phosphor 2: Silicone resin layer containing phosphor 3: LED element 4: Gold wire 5: Ceramic substrate having external electrode 6: Reflector 7: External lead 8: Underfill material 9: Gold bumps 10a, 10b: Release film 11: Two-layer silicone resin sheet

Claims (4)

The following layer (2), which is made of a thermosetting silicone resin composition containing a phosphor on the surface of the LED element and is in a solid or semisolid state at room temperature, and a transparent or translucent thermosetting silicone resin composition A thermosetting silicone resin sheet comprising the following layer (1) in a plastic solid or semi-solid state at room temperature, wherein the difference in softening temperature between the layer (2) and the layer (1) is within 10 ° C. The layer (2) and the layer (1) are all in an unreacted state , arranged in the order of the LED element, the layer (2), and the layer (1), and the resin sheet is heat-cured to contain a phosphor. The manufacturing method of the light-emitting device which has a LED element which coat | covers and seals the LED element surface with the hardened | cured material which has a cured silicone resin layer (2) and the cured silicone resin layer (1) which does not contain fluorescent substance.
Layer (2):
(A) consisting essentially of R ¹ SiO _1.5 units, R ² ₂ SiO units, and R ³ _a R ⁴ _b SiO _{(4-ab) / 2} units (where R ¹ , R ² , And R ³ independently represents a methyl group, an ethyl group, a propyl group, a cyclohexyl group, or a phenyl group, R ⁴ independently represents a vinyl group or an allyl group, a is 0, 1 or 2, and b is 1 or 2 and a + b is 2 or 3.) An organopolysiloxane having a resin structure in which at least a part of the R ² ₂ SiO unit is continuously repeated, and the number of repetitions thereof is 5 to 300.
(B) consisting essentially of R ¹ SiO _1.5 units, R ² ₂ SiO units, and R ³ _c H _d SiO _{(4-cd) / 2} units (where R ¹ , R ² and R ³ is independently as described above, c is 0, 1 or 2, d is 1 or 2, and c + d is 2 or 3.
Organohydrogenpolysiloxane having a resin structure in which at least a part of the R ² ₂ SiO unit is continuously repeated and the number of repetitions thereof is 5 to 300:
(A) The quantity which becomes 0.1-4.0 by the molar ratio of the hydrogen atom couple | bonded with the silicon atom in (B) component with respect to the sum total of the vinyl group and allyl group in a component,
(C) Platinum group metal catalyst: effective amount of curing, and (D) thermosetting silicone resin composition containing phosphor Layer (1):
(A) substantially comprising R ¹ SiO _1.5 units, R ² ₂ SiO units, and R ³ _a R ⁴ _b SiO _{(4-ab) / 2} units (where R ¹ , R ² and R ³ independently represent a methyl group, an ethyl group, a propyl group, a cyclohexyl group, or a phenyl group, R ⁴ independently represents a vinyl group or an allyl group, a is 0, 1 or 2, and b is 1 or 2 and a + b is 2 or 3.), a resin structure comprising a structure in which at least a part of the R ² ₂ SiO unit is continuously repeated, and the number of repetitions is 5 to 300. Organopolysiloxane,
(B) substantially comprising R ¹ SiO _1.5 units, R ² ₂ SiO units, and R ³ _c H _d SiO _{(4-cd) / 2} units (where R ¹ , R ² And R ³ is independently as described above, c is 0, 1 or 2, d is 1 or 2, and c + d is 2 or 3.),
Organohydrogenpolysiloxane having a resin structure in which at least a part of the R ² ₂ SiO unit is continuously repeated and the number of repetitions thereof is 5 to 300:
(A) The amount of hydrogen atoms bonded to silicon atoms in component (B) relative to the total of vinyl groups and allyl groups in component (A) in a molar ratio of 0.1-4.0, and (C) platinum group metal system Catalyst: Thermosetting silicone resin composition containing an effective amount of curing and no phosphor   The method for manufacturing a light emitting device according to claim 1, wherein the layer (2) containing the phosphor has a thickness of 20 to 100 µm, and the transparent or translucent layer (1) not containing the phosphor has a thickness of 20 to 500 µm. .   In the layer (2), the phosphor of the component (D) is 0.1 to 300 parts by mass with respect to a total of 100 parts by mass of the components (A) to (C). Method.   The method for manufacturing a light emitting device according to any one of claims 1 to 3, wherein in the layer (2), the particle size of the phosphor of the component (D) is 10 nm or more.

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