WO2012144494A1

WO2012144494A1 - Method for producing led substrate

Info

Publication number: WO2012144494A1
Application number: PCT/JP2012/060357
Authority: WO
Inventors: 平松　靖二; 井戸　義幸; 渉古市
Original assignee: イビデン株式会社
Priority date: 2011-04-18
Filing date: 2012-04-17
Publication date: 2012-10-26
Also published as: JP5791947B2; JP2012227292A

Abstract

This method for producing an LED substrate includes: forming (S12) a conductor layer on a substrate; forming (S14), on the substrate having the conductor layer, a silicone resin layer containing reflective particles and covering the conductor layer; forming (S16) an aperture in the silicone resin layer by means of laser light irradiation; and eliminating (S17) residue remaining at the aperture of the silicone resin layer by means of blasting processing.

Description

LED substrate manufacturing method

The present invention relates to a method for manufacturing an LED substrate.

Various LED substrates for mounting LED elements used for LED (light emitting diode) lights, LED lighting, and the like have been developed. Patent Document 1 discloses a base material, an insulating layer formed on the base material, a circuit formed on the insulating layer, a nickel layer or an aluminum layer formed on the circuit, an insulating layer, and a circuit. An LED substrate having a white film formed thereon is disclosed. Here, an opening is formed in the white film. A solder layer is formed in the exposed part of the nickel layer or aluminum layer of the circuit of the LED base by the opening. Then, the LED element is mounted on the LED substrate by solder provided in the opening. As a resin used for the white film, an epoxy resin, an acrylic resin, and a resin using both an epoxy resin and an acrylic resin are disclosed.

JP 2009-130234 A

However, in the method described in Patent Document 1, since an ultraviolet curable acrylic resin or epoxy resin is used, the white film is exposed to ultraviolet light, and this is developed with a solvent to provide an opening. It is thought that. However, since the white film is exposed to light for a long time in the LED element, when a photosensitive resin (for example, an ultraviolet curable resin) is used as the white film, the curing progresses too much and a dimensional change may occur in the opening. Or conversely, problems such as degradation of the resin due to cleavage of molecular chain bonds may occur.

The present invention provides a method capable of providing an opening in a white film without exposure and development processing.

The manufacturing method of the LED substrate according to the present invention is as follows:
Forming a conductor layer on the substrate;
Forming a silicone resin layer on the substrate having the conductor layer and covering the conductor layer and containing reflector particles;
Forming an opening in the silicone resin layer by laser light irradiation;
Removing the residue remaining in the opening of the silicone resin layer by blasting;
including.

The silicone resin layer is preferably a solder resist.

Prior to the laser light irradiation, a protective film is formed on the silicone resin layer, and in the laser light irradiation, the laser light penetrates the protective film and forms the opening in the silicone resin layer. It is preferable.

It is preferable to remove the protective film after the blast treatment.

It is preferable that the residue contains silica (SiO ₂ ).

The silicone resin layer covers the conductor layer before the laser beam irradiation, and the conductor layer is exposed at the opening of the silicone resin layer by the laser beam irradiation and the blast treatment. It is preferable.

The reflector particles are preferably made of titanium oxide.

The titanium oxide is preferably anatase type titanium oxide.

The silicone resin layer preferably contains at least one of zirconia, alumina, and silica as the reflector particles.

The light source of the laser light is preferably a CO ₂ laser.

It is preferable that the abrasive grains used for the blasting treatment are water-soluble.

The average particle diameter of the abrasive grains used for the blast treatment is preferably in the range of 0.1 to 200 μm.

The LED substrate is preferably an LED substrate for a blue LED or an ultraviolet LED.

In the present invention, an opening is formed in the silicone resin layer by laser light irradiation. An opening can be easily formed in the silicone resin layer by changing the predetermined portion of the silicone resin layer to an inorganic substance (silica and reflector particles) that can be easily removed by laser light irradiation. Furthermore, the reliability of connection between the conductor layer and the LED element can be improved by removing silica remaining in the opening of the silicone resin layer by blasting.

It is sectional drawing which shows the LED board and light emitting module which concern on embodiment of this invention. It is a top view which shows the LED board and light emitting module which concern on embodiment of this invention. It is a flowchart which shows the manufacturing method of the LED board which concerns on embodiment of this invention. It is a figure for demonstrating the process of preparing the resin substrate in the manufacturing method shown in FIG. It is a figure for demonstrating the 1st process of forming the conductor layer in the manufacturing method shown in FIG. It is a figure for demonstrating the 2nd process after the 1st process of FIG. 5A. It is a figure for demonstrating the 3rd process after the 2nd process of FIG. 5B. It is a figure for demonstrating the process of forming the silicone resin layer containing the reflector particle | grains in the manufacturing method shown in FIG. It is a figure for demonstrating the process of forming the protective film in the manufacturing method shown in FIG. It is a figure for demonstrating the laser irradiation process in the manufacturing method shown in FIG. It is a figure which shows the opening part of the silicone resin layer containing the reflector particle | grains after the laser irradiation of FIG. It is opened by irradiation of CO ₂ laser light to the silicone resin layer containing an anatase type titanium oxide is formed on the conductive layer, the residue of a scanning electron microscope (SEM) photographs. It is a graph which shows the spectrum which analyzed the area | region shown by FIG. 10A with the energy dispersive X-ray analyzer. It is a figure for demonstrating the blasting process in the manufacturing method shown in FIG. It is a figure which shows the opening part of the silicone resin layer containing the reflector particle | grains after the blast process of FIG. 11A. It is a figure for demonstrating the process of removing the protective film in the manufacturing method shown in FIG. It is a figure for demonstrating the process of forming the corrosion-resistant layer in the manufacturing method shown in FIG. In other embodiment of this invention, it is a top view which shows a different laser irradiation aspect. It is sectional drawing of FIG. 14A. It is a figure for demonstrating the 1st process of forming the conductor layer which concerns on other embodiment of this invention. It is a figure for demonstrating the 2nd process after the 1st process of FIG. 15A. It is a figure for demonstrating the 3rd process after the 2nd process of FIG. 15B. It is a figure for demonstrating the 4th process after the 3rd process of FIG. 15C. In other embodiment of this invention, it is a flowchart which shows the manufacturing method of the LED board which removes a protective film before a blast process.

A silicone resin that is stable to light is unlikely to turn yellow. Further, even when particles acting as an oxidation catalyst such as TiO ₂ coexist with the silicone resin, the molecular chain of the silicone resin is difficult to cleave. Silicone resins are discolored (especially discolored to yellow) or deteriorated in properties (for example, electrical insulation, water resistance, heat resistance, etc.) even when exposed to LED light of blue to ultraviolet light of 500 nm or less. , Impact resistance, light resistance, dimensional stability, etc.) are less likely to occur. In the embodiment of the present invention, laser processing is employed to provide an opening in the silicone resin film without exposing the silicone resin. Thereby, it becomes possible to suppress the characteristic fall of a silicone resin. In addition, when the silicone resin film is irradiated with laser light, it is found that SiO ₂ remains as a residue on the bottom surface of the opening formed in the silicone resin film, and this is removed by a blasting process, so that electrical conduction is achieved. An opening that does not interfere is formed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the figure, arrows Z1 and Z2 indicate the thickness direction of the substrate corresponding to the normal direction of the main surface (front and back surfaces) of the substrate. On the other hand, arrows X1, X2 and Y1, Y2 indicate the sides of the substrate orthogonal to the Z direction. The main surface of the substrate is an XY plane. The side surface of the substrate is an XZ plane or a YZ plane.

The two main surfaces of the substrate facing the opposite normal directions are referred to as a first surface (Z1 side surface) and a second surface (Z2 side surface). Directly below means the Z direction (Z1 side or Z2 side).

The conductor layer is a layer composed of one or more conductor patterns. The conductor layer may include a conductor pattern that constitutes an electric circuit, for example, a wiring (including a ground), a pad, a land, or the like, or a planar conductor pattern that does not constitute an electric circuit.

孔 Holes are not limited to through holes, but include non-through holes.

In addition to wet plating such as electrolytic plating, plating includes dry plating such as PVD (Physical Vapor Deposition) and CVD (Chemical Vapor Deposition).

* Light is not limited to visible light. In addition to visible light, light includes short-wave electromagnetic waves such as ultraviolet rays and X-rays and long-wave electromagnetic waves such as infrared rays.

FIG. 1 shows a schematic structure of an LED substrate 100 manufactured by the LED substrate manufacturing method according to this embodiment and a light emitting module 1000 using the LED substrate 100. FIG. 1 is a cross-sectional view illustrating an LED substrate and a light emitting module according to an embodiment of the present invention.

As shown in FIG. 1, the LED substrate 100 includes a resin substrate 10 (resin substrate), a conductor layer 21, and a silicone resin layer 11 containing reflector particles. Hereinafter, one of the front and back surfaces (two main surfaces) of the substrate 10 is referred to as a first surface F1, and the other is referred to as a second surface F2.

The LED substrate 100 becomes the light emitting module 1000 by mounting the LED element 200. In the present embodiment, the LED element 200 is mounted on the first surface F1 side of the substrate 10. The LED element 200 is, for example, a blue LED. However, the present invention is not limited to this, and for example, the LED element 200 may be an ultraviolet LED or the like. The wavelength of light is desirably 500 nm or less.

The substrate 10 of the present embodiment is an insulating resin substrate having a rectangular shape, for example. In this embodiment, the board | substrate 10 consists of an epoxy resin containing the reinforcing material which consists of glass fiber (for example, glass cloth or a glass nonwoven fabric). Specifically, the substrate 10 is made of glass fiber impregnated with an epoxy resin (hereinafter referred to as glass epoxy). Here, the epoxy resin is a thermosetting resin. The reinforcing material is a material having a smaller coefficient of thermal expansion than the main material (in the present embodiment, epoxy resin). By including glass fiber in the substrate 10, it is possible to suppress cracks in the substrate 10.

In addition, the material which comprises a reinforcing material is not restricted to glass fiber, It may replace with glass fiber and may use another inorganic material. For example, you may use the reinforcing material which consists of an aramid fiber (for example, an aramid nonwoven fabric) or a silica filler.

Also, the resin constituting the resin substrate is arbitrary. For example, polyester resin, bismaleimide triazine resin (BT resin), imide resin (polyimide), phenol resin, or allylated phenylene ether resin (A-PPE resin) may be used instead of epoxy resin.

In this embodiment, a resin substrate is employed as the substrate 10. Since the base material made of resin becomes difficult to break due to its high flexibility, it is easy to make it thinner than a ceramic substrate made of alumina or AlN (aluminum nitride). In addition, compared with a ceramic substrate, a resin substrate is easily available at a low cost, and processing such as drilling is easy.

In the present embodiment, the conductor layer 21 is formed on the first surface F1 of the substrate 10. The conductor layer 21 includes

wiring patterns

21 c and 21 d that can function as wirings or pads of the LED element 200. The wiring pattern 21c is electrically connected to the anode (or cathode) of the LED element 200, for example, and the wiring pattern 21d is electrically connected to the cathode (or anode) of the LED element 200, for example.

The conductor layer 21 is the outermost conductor layer on the first surface F1 side. On the first surface F1 and the conductor layer 21 of the substrate 10, a silicone resin layer 11 containing reflector particles is formed. Regardless of the color or material of the substrate 10, the reflectance can be increased by the silicone resin layer 11 containing the reflector particles. The thickness of the silicone resin layer 11 containing the reflector particles is, for example, in the range of 10 to 500 μm. In the present embodiment, since the silicone resin layer 11 containing the reflective material particles can function as a solder resist, it is not necessary to separately form a solder resist.

An opening 11a is formed in the silicone resin layer 11 containing the reflector particles. In the opening 11 a, a corrosion-resistant layer 21 a is formed on the conductor layer 21, and portions exposed to the opening 11 a (the corrosion-resistant layer 21 a and the conductor layer 21) serve as pads on the surface of the LED substrate 100. This pad serves as an external connection terminal for electrical connection with the LED element 200, for example.

In the present embodiment, the silicone resin layer 11 is made of a silicone resin and contains anatase-type titanium oxide (for example, titanium dioxide). In this embodiment, anatase-type titanium oxide functions as reflector particles, and a silicone resin functions as a binder. Titanium oxide makes it easy to obtain a high reflectance, and in particular, anatase-type titanium oxide makes it easy to obtain a high reflectance with respect to light having wavelengths in the blue region and the ultraviolet region. In addition, the silicone resin is resistant to the photocatalytic action of titanium oxide and has high stability with respect to light having a wavelength in the blue region and the ultraviolet region, so that it is difficult to yellow. However, the material of the silicone resin layer 11 containing the reflector particles is not limited to this. For example, instead of anatase type titanium oxide, at least one selected from rutile type titanium oxide, zirconia, alumina, or silica is used. May be included. Further, a mixture thereof (for example, mullite or steatite) may be used.

The corrosion-resistant layer 21a protects the conductor layer 21. In the present embodiment, the corrosion resistant layer 21a is made of, for example, a Ni / Au film. However, it is not limited to this, The material of the corrosion-resistant layer 21a is arbitrary. Moreover, the corrosion-resistant layer 21a is not an essential configuration, and may be omitted if not necessary.

FIG. 2 shows the shape of the conductor layer 21 (

wiring patterns

21c and 21d) of the LED substrate 100 according to this embodiment. FIG. 2 is a plan view showing the LED substrate and the light emitting module according to the embodiment of the present invention.

As shown in FIG. 2, in the present embodiment, the rectangular wiring pattern 21c and the rectangular wiring pattern 21d are arranged with a predetermined interval. The LED element 200 is disposed on the

wiring patterns

21c and 21d. However, the shape of the conductor layer 21 (wiring pattern layer) is not limited to this and is arbitrary.

As shown in FIG. 1, in the light emitting module 1000 of the present embodiment, the LED element 200 is mounted by a flip chip method. Thereby, the electrode of the LED element 200 is electrically connected to the

wiring patterns

21c and 21d of the conductor layer 21 via the solder 200a.

The LED substrate 100 of this embodiment has flexibility. Specifically, in the present embodiment, the silicone resin layer 11 containing the reflector particles is composed of a silicone resin having a low elastic modulus. Further, the substrate 10 (resin substrate) has flexibility due to its thin thickness. For this reason, the LED substrate 100 tends to have flexibility.

When the LED substrate 100 has flexibility, the LED substrate 100 is easily bent to absorb stress. For this reason, when an impact is applied by dropping or the like, the LED substrate 100 is hardly damaged.

The thickness of the substrate 10 is preferably in the range of 0.05 mm to 0.50 mm. If the thickness of the substrate 10 is less than 0.05 mm, the rigidity of the substrate 10 becomes low and the substrate 10 is easily deformed, and the LED element mounted on the surface and the solder etc. of the connection portion of the LED substrate are cracked. It becomes easy. For this reason, the power feeding portion to the LED element is easily disconnected. On the other hand, if the thickness of the substrate 10 exceeds 0.50 mm, it becomes difficult to dissipate the heat generated by the LED element to the back surface of the LED substrate, so that the LED element is easily exposed to high heat. Therefore, when the LED element becomes high temperature, the light emission efficiency of the LED element tends to decrease.

In the present embodiment, the substrate 10 is made of resin (for example, glass epoxy). Since the resin has higher flexibility than the ceramic, the flexibility of the LED substrate 100 can be easily obtained, and it is difficult to break even when dropped.

The light emitting module 1000 of the present embodiment emits light LT1 to LT3, for example, from the LED element 200 as shown in FIG. Any wavelength of light (or the type of LED element 200) can be adopted depending on the application of the light emitting module 1000. The light of the light emitting module 1000 is white light, for example. White light can be produced, for example, by combining a blue LED (LED element 200) and a phosphor. Specifically, white light can be produced by applying blue light emitted from a blue LED to a yellow phosphor. The light emitting module 1000 that emits white light can be used for illumination (such as a light bulb or a car headlight) or a backlight of a liquid crystal display (such as a large display or a mobile phone display).

The light emitted from the LED element 200 includes, for example, light LT1 directed upward of the LED element 200, light LT2 directed laterally of the LED element 200, and light LT3 directly below the LED element 200. In the light emitting module 1000 of the present embodiment, the light LT2 and LT3 are each reflected by the silicone resin layer 11 containing the reflector particles. Thereby, it becomes difficult for the light of the LED element 200 to hit the substrate 10, and deterioration of the substrate 10 (particularly, deterioration of the resin) due to the light is suppressed. In the present embodiment, a part of the silicone resin layer 11 containing the reflector particles is disposed directly under or near the LED element 200. For this reason, the light LT3, which is considered to deteriorate the substrate 10 in particular, is also reflected by the silicone resin layer 11 containing the reflector particles.

Also, the light LT2 and LT3 are each reflected by the silicone resin layer 11 containing the reflector particles and become light in the same direction as the light LT1, so that the light emission efficiency of the light emitting module 1000 can be easily increased.

Hereinafter, a method for manufacturing the LED substrate 100 will be described with reference to FIG. FIG. 3 is a flowchart showing a method for manufacturing the LED substrate 100 according to the embodiment of the present invention. The flowchart of FIG. 3 shows a schematic content and procedure of the method for manufacturing the LED substrate 100. In the present embodiment, after manufacturing a large number of LED boards 100 with one panel (steps S11 to S19), they are cut out individually (step S20).

FIG. 4 is a view for explaining a step of preparing a resin substrate (substrate 10) in the manufacturing method shown in FIG. FIG. 5A is a diagram for explaining a first step of forming the conductor layer 21 in the manufacturing method shown in FIG. 3. FIG. 5B is a diagram for explaining a second step after the first step of FIG. 5A. FIG. 5C is a diagram for explaining a third step after the second step of FIG. 5B. FIG. 6 is a diagram for explaining a process of forming the silicone resin layer 11 containing the reflector particles in the manufacturing method shown in FIG. FIG. 7 is a diagram for explaining a process of forming the protective film 1003 in the manufacturing method shown in FIG. FIG. 8 is a view for explaining a laser irradiation step in the manufacturing method shown in FIG. FIG. 9 is a view showing the opening 11a of the silicone resin layer 11 containing the reflector particles after the laser irradiation of FIG. FIG. 11A is a diagram for explaining a blasting process in the manufacturing method shown in FIG. 3. FIG. 11B is a diagram showing the opening 11a of the silicone resin layer 11 containing the reflector particles after the blasting process of FIG. 11A. FIG. 12 is a diagram for explaining a process of removing the protective film 1003 in the manufacturing method shown in FIG. FIG. 13 is a diagram for explaining a process of forming the corrosion-resistant layer 21a in the manufacturing method shown in FIG.

In step S11 of the flowchart of FIG. 3, as shown in FIG. 4, a resin substrate (substrate 10) is prepared as a starting material. In this embodiment, at this stage, the substrate 10 is made of a glass epoxy that is completely cured.

Subsequently, in step S12 of the flowchart of FIG. 3, as shown in FIG. 5A, a conductor layer 1001 (for example, a full pattern) is formed on the first surface F1 of the substrate 10. The conductor layer 1001 is made of, for example, copper foil. However, the present invention is not limited to this, and the conductor layer 1001 may be composed of an electrolytic plating film (upper layer) and a copper foil (lower layer). The conductor layer 1001 may be made of an electrolytic plating film (upper layer), an electroless plating film (intermediate layer), and a copper foil (lower layer).

Subsequently, in step S13 of the flowchart of FIG. 3, the conductor layer 1001 formed on the first surface F1 of the substrate 10 is patterned.

Specifically, as shown in FIG. 5B, an etching resist 1002 having an opening 1002a is formed on the main surface (on the conductor layer 1001) on the first surface F1 side, for example, by lithography. The opening 1002a has a pattern corresponding to the conductor layer 21 (FIG. 1).

Subsequently, a portion of the conductor layer 1001 formed on the first surface F1 of the substrate 10 that is not covered with the etching resist 1002 (portion exposed through the opening 1002a) is removed using, for example, an etching solution. Thereafter, the etching resist 1002 is removed. As a result, as shown in FIG. 5C, the conductor layer 1001 is patterned, and the conductor layer 21 that can function as the wiring of the LED element 200 is formed on the first surface F1 of the substrate 10. Note that the etching is not limited to wet, and may be dry.

Subsequently, in step S14 of the flowchart of FIG. 3, the silicone resin layer 11 thicker than the conductor layer 21 is formed on the first surface F1 of the substrate 10 by screen printing, for example, as shown in FIG. The silicone resin layer 11 contains reflector particles. Specifically, for example, an anatase-type titanium oxide is mixed with an uncured silicone resin and printed on the first surface F1 of the substrate 10. Subsequently, for example, the uncured silicone resin is cured by holding at 100 to 150 ° C. for 10 to 60 minutes. Thereby, the silicone resin 11 containing anatase type titanium oxide as the reflector particles is obtained.

Subsequently, in step S15 of the flowchart of FIG. 3, as shown in FIG. 7, a protective film 1003 is formed on the silicone resin layer 11 containing the reflector particles. Thus, by forming the protective film 1003 prior to laser light irradiation (step S16 in FIG. 3), which will be described later, contamination (black spots, etc.) of the silicone resin layer 11 due to laser light irradiation is suppressed or prevented. Can do. The protective film 1003 is made of, for example, PET (polyethylene terephthalate). However, the present invention is not limited to this, and it is preferable to use a protective film 1003 made of an appropriate material depending on the conditions of laser irradiation, blasting, and the like.

Subsequently, in step S16 of the flowchart of FIG. 3, as shown in FIG. 8, an opening 11a is formed in the silicone resin layer 11 containing the reflector particles by irradiation with laser light. The laser beam penetrates the protective film 1003 and forms the opening 11a in the silicone resin layer 11, but does not penetrate the conductor layer 21.

Here, the laser beam irradiation is partially performed without using a light shielding mask. Specifically, the laser irradiation is stopped in the non-irradiated portion, and the laser beam is irradiated only on the portion to be irradiated. However, the present invention is not limited to this, and a light shielding mask may be used (see FIGS. 14A and 14B described later).

The adjustment of the laser intensity (light quantity) is preferably performed by pulse control. Specifically, for example, when changing the laser intensity, the number of shots (number of irradiations) is changed without changing the laser intensity per shot (one irradiation). That is, when a desired laser intensity cannot be obtained with one shot, the same irradiation position is irradiated with laser light again. According to such a control method, the time for changing the irradiation condition can be omitted, so that it is considered that the throughput is improved. However, the method is not limited to this, and the laser intensity adjustment method is arbitrary. For example, the irradiation conditions may be determined for each irradiation position, and the number of irradiations may be fixed (for example, one shot for one irradiation position). Further, in the case of performing laser irradiation a plurality of times at the same irradiation position, the laser intensity may be changed for each shot.

As a laser light source, a CO ₂ laser is preferable. According to the CO ₂ laser, laser light having energy necessary for penetrating the silicone resin layer 11 containing the protective film 1003 and the reflector particles can be easily obtained.

As shown in FIG. 9, a residue 1004 is formed in the opening 11a after the laser light irradiation. The residue 1004 has a thickness of about 0.5 μm, for example. The inventor has confirmed that the residue 1004 is mainly composed of silica (SiO ₂ ) and reflector particles.

FIG. 10A is a scanning electron microscope (SEM) photograph of the residue opened by irradiation of CO ₂ laser light in the silicone resin layer containing anatase-type titanium oxide formed on the conductor layer. FIG. 10B is a graph showing a spectrum obtained by analyzing the region shown in FIG. 10A with an energy dispersive X-ray analyzer.

FIG. 10B shows that silicon (Si) and oxygen (O) were detected on the surface of the conductor layer 21 (Cu) irradiated with the laser beam. The residue 1004 is presumed that the silicone resin constituting the silicone resin layer 11 containing the reflector particles is changed by laser, and since it is an inorganic substance, in a general cleaning method using a potassium permanganate aqueous solution or the like, It is difficult to remove completely.

Therefore, in the present embodiment, in step S17 of the flowchart of FIG. 3, as shown in FIG. 11A, the residue 1004 remaining in the opening 11a is removed by blasting. The silicone resin layer 11 containing the reflector particles covers the conductor layer 21 formed on the substrate 10 (base material) before the laser beam irradiation (step S16 in FIG. 3) (see FIG. 7). . Irradiation with laser light transforms the silicone resin into silica, which can be easily removed by blasting (step S17 in FIG. 3). By hitting the abrasive grains shot by the blast treatment against the residue 1004 (SiO ₂ and reflector particles), the residue 1004 can be removed by the impact. Thus, as shown in FIG. 11B, the conductor layer 21 is exposed at the opening 11a.

It is preferable that the abrasive grains used for the blast treatment are water-soluble. If water-soluble abrasive grains are used, the abrasive grains dissolve in water by washing with water after the blast treatment, and it becomes easy to completely remove the abrasive grains.

As the abrasive grains used for the blasting treatment, for example, NaHCO ₃ (bicarbonate) can be used. NaHCO ₃ (soda) does not easily react with the silicone resin layer, the conductor layer, and the substrate constituting the LED substrate, and easily dissolves in water, and thus hardly remains on the LED substrate.

The average particle diameter of the abrasive grains used for the blast treatment is preferably in the range of 0.1 to 200 μm. When the average particle diameter of the abrasive grains is 0.1 μm or more, the kinetic energy of the abrasive grains can be increased, so that the residue 1004 can be easily removed. When the average particle diameter of the abrasive grains is 200 μm or less, the unevenness of the processed surface (white film of the LED substrate) can be reduced, and the white film of the LED substrate can be easily made smooth. If the white film of the LED substrate is not a smooth surface, the white film is liable to be chipped or cracked.

Subsequently, in step S18 of the flowchart of FIG. 3, the protective film 1003 is removed as shown in FIG. In this embodiment, since the protective film 1003 is removed after the blasting process, the silicone resin layer 11 containing the reflector particles is also covered with the protective film 1003 during the blasting process. Since the residue 1004 is composed of silica and reflector particles, it is more easily processed by blasting than the protective film 1003. For this reason, according to the blasting process, it becomes easy to remove only the residue 1004. As a result, damage to the silicone resin layer 11 due to the blast treatment is easily suppressed or prevented.

Subsequently, in step S19 of the flowchart of FIG. 3, as shown in FIG. 13, a corrosion resistant layer 21a made of, for example, a Ni / Au film is formed on the conductor layer 21 by electrolytic plating, electroless plating, sputtering, or the like. Thereby, the LED substrate 100 is completed. In addition, you may form the corrosion-resistant layer 21a which consists of an organic protective film by performing OSP (Organic | Solderability | preservatives) process (refers to processes, such as an organic protective film, a heat-resistant water-soluble preflux, and a preflux).

Thereafter, in step S20 of the flowchart of FIG. 3, each of the LED substrates 100 formed on the panel is subjected to outer shape processing to obtain individual LED substrates 100. After the inspection, only good products are used as products. Further, by mounting the LED element 200 on the LED substrate 100 thus obtained, the light emitting module 1000 as shown in FIG. 1 is completed.

In the manufacturing method of this embodiment, the conductor layer 21 is formed on the substrate 10 (base material), and the silicone resin layer 11 that covers the conductor layer 21 and contains the reflector particles is formed on the substrate 10 having the conductor layer 21. Forming the opening 11a in the silicone resin layer 11 (silicone resin layer) containing the reflector particles by irradiating with laser light, and removing the residue 1004 remaining in the opening 11a by blasting And including. Thereby, the residue 1004 (residue) remaining in the opening 11a of the silicone resin layer 11 containing the reflector particles can be suitably removed. Further, since the residue 1004 is removed, the LED substrate 100 and the LED element 200 are electrically connected to each other without the residue 1004, and thus the silicone resin layer 11 containing the reflector particles. The reliability of the electrical connection between the LED substrate 100 and the LED element 200 in the opening 11a of the (solder resist) can be enhanced.

The manufacturing method of the present embodiment is suitable for manufacturing an LED substrate for a blue LED or an ultraviolet LED. Specifically, blue light or ultraviolet light is likely to damage a resin containing a C═C bond or a C—C bond. Therefore, a blue LED or an ultraviolet LED deteriorates a general carbon skeleton resin including an epoxy resin. Easy to do. In this respect, the manufacturing method of the present embodiment provides a method for processing an LED substrate that uses a silicone resin having a siloxane bond (Si—O unit) in the main chain and is less damaged by blue light or ultraviolet light. The manufacturing method of the LED substrate suitable for use for ultraviolet or ultraviolet LED is obtained.

The present invention is not limited to the above embodiment. For example, the present invention can be modified as follows.

In the above embodiment, the laser beam is irradiated only to the portion to be irradiated without using the light shielding mask. However, the present invention is not limited to this. For example, in step S16 of the flowchart of FIG. 3, as shown in FIGS. 14A and 14B, a light shielding mask 1005 (for example, a metal mask) having an opening 1005a is placed on the Z1 side of the silicone resin layer 11 containing the reflector particles. It may be installed and the entire surface may be irradiated with laser light. The opening 1005a has a pattern corresponding to the opening 11a (see FIG. 13). When irradiating the entire surface of the irradiated body with laser light, for example, the irradiated body may be fixed and the laser light (strictly speaking) may be moved by a galvanometer mirror or the like. And the irradiated object may be moved by a conveyor or the like. Further, the laser beam may be changed to line light by a cylindrical lens or the like. A plurality of laser devices (two or more exposure heads) may be used.

According to the method shown in FIGS. 14A and 14B, the laser light is irradiated on the entire surface of the silicone resin layer 11 containing the reflector particles, but the light other than the laser light passing through the opening 1005a is shielded by the light shielding mask 1005. The silicone resin layer 11 containing the reflector particles is not irradiated. On the other hand, the light that has passed through the opening 1005a is applied to the silicone resin layer 11 containing the reflector particles to form the opening 11a (see FIG. 13). For this reason, the opening part 11a can be formed in a desired position also by such a method. In addition, in the example of FIG. 14A and FIG. 14B, although the protective film 1003 (refer FIG. 8) is not used, you may use the protective film 1003 if needed.

In the above embodiment, the conductor layer 21 is formed by the subtractive method, but the method of forming the conductor layer 21 is arbitrary. For example, any one of a panel plating method, a pattern plating method, a full additive method, a semi-additive (SAP) method, a subtractive method, a transfer method, and a tenting method, or a combination of any two or more thereof. The conductor layer 21 may be formed.

15A to 15D show an example in which the conductor layer 21 is formed by the SAP method. FIG. 15A is a diagram for explaining a first step of forming a conductor layer according to another embodiment of the present invention. FIG. 15B is a diagram for explaining a second step after the first step of FIG. 15A. FIG. 15C is a diagram for explaining a third step after the second step of FIG. 15B. FIG. 15D is a diagram for explaining a fourth step after the third step in FIG. 15C.

In this example, as shown in FIG. 15A, first, a substrate 10 is prepared, and an electroless plating film 2001 of, for example, copper is formed on the first surface F1 of the substrate 10 by a chemical plating method. Subsequently, as shown in FIG. 15B, a plating resist 2002 having an opening 2002a is formed on the electroless plating film 2001 by lithography or printing. The opening 2002a has a pattern corresponding to the conductor layer 21 (FIG. 1).

Subsequently, as shown in FIG. 15C, for example, copper electroplating 2003 is formed in the opening 2002a of the plating resist 2002 by a pattern plating method. Specifically, copper, which is a material to be plated, is connected to the anode, and an electroless plating film 2001, which is a material to be plated, is connected to the cathode, and immersed in a plating solution. Then, a direct current voltage is applied between the two electrodes to pass a current, and copper is deposited on the surface of the electroless plating film 2001. Thereafter, as shown in FIG. 15D, the conductive layer 21 (see FIG. 5C) is formed by removing the plating resist 2002 using, for example, a predetermined stripping solution and then removing the unnecessary electroless plating film 2001. .

Note that the seed layer for electrolytic plating is not limited to the electroless plating film, and a sputtered film or the like may be used as the seed layer instead of the electroless plating film 2001.

With respect to other points as well, the configurations of the LED substrate 100 and the light emitting module 1000, and the types, performances, dimensions, materials, shapes, number of layers, and arrangements of the components are arbitrary within the scope of the present invention. Can be changed.

The mounting method of the LED element 200 is not limited to the flip chip and is arbitrary. For example, the LED element 200 may be mounted by wire bonding.

The shape and material of the substrate 10 are basically arbitrary. For example, the substrate 10 may be made of ceramic. Moreover, you may be comprised from the several layer which consists of a different material.

In the above embodiment, the LED substrate 100 is a printed wiring board having only one conductor layer (conductor layer 21). However, a multilayer printed wiring board that is multilayered using the substrate 10 as a core substrate may be used.

Moreover, the material of each conductor layer is not limited to the above, and can be changed according to the application. For example, a metal material other than copper or a non-metal conductor material may be used as the material of the conductor layer.

The LED element 200 is not limited to a blue LED or an ultraviolet LED, but may be an LED having another wavelength.

The manufacturing process of the LED substrate 100 and the light emitting module 1000 is not limited to the order and contents shown in the flowchart of FIG. 3, and the order and contents can be arbitrarily changed without departing from the gist of the present invention. . Moreover, you may omit the process which is not required according to a use etc.

FIG. 16 is a flowchart showing a method of manufacturing an LED substrate in which the protective film is removed before blasting in another embodiment of the present invention. The residue 1004 (see FIG. 9) is composed of, for example, inorganic substances (silica and reflector particles), and the silicone resin layer 11 contains, for example, reflector particles. The residue 1004 is formed thinner than the silicone resin layer 11, for example. For this reason, the residue 1004 is more easily removed by blasting than the silicone resin layer 11. For this reason, as shown in FIG. 16, you may remove the protective film 1003 (refer FIG. 8) before a blast process. However, in order to reduce the damage of the silicone resin layer 11 due to the blast treatment, it is preferable to remove the protective film 1003 after the blast treatment.

The above embodiments and modifications can be arbitrarily combined. It is preferable to select an appropriate combination according to the application. For example, the laser irradiation mode shown in FIGS. 14A and 14B, the conductor layer forming method shown in FIGS. 15A to 15D, and the manufacturing method shown in FIG. 16 may be combined.

The embodiment of the present invention has been described above. However, various modifications and combinations required for design reasons and other factors are not limited to the invention described in the “claims” or the “mode for carrying out the invention”. It should be understood that it is included in the scope of the invention corresponding to the specific examples described in the above.

The contents of JP 2009-130234 A are incorporated in this specification.

This application claims priority based on Japanese Patent Application No. 2011-92523 filed on April 18, 2011, and Japanese Patent Application No. 2011-92523 is included in the specification of this application. The contents of the description, claims and drawings are incorporated.

The method for producing an LED substrate according to the present invention is suitable for producing an LED substrate for a blue LED or an ultraviolet LED, for example.

DESCRIPTION OF SYMBOLS 10 Board | substrate 10b Filled conductor 11 Silicone resin layer containing reflector particle | grains 11a Opening part 21 Conductive layer 21a Corrosion-resistant layer

21c Wiring pattern

21d Wiring pattern 100 LED board 200 LED element 200a Solder 1000 Light emitting module 1001 Conductive layer 1002 Etching resist 1002a Opening part 1003 Protective film 1004 Residue 1005 Shading mask 1005a Opening 2001 Electroless plating film 2002 Plating resist 2002a Opening 2003 Electrolytic plating

Claims

Forming a conductor layer on the substrate;
Forming a silicone resin layer on the substrate having the conductor layer and covering the conductor layer and containing reflector particles;
Forming an opening in the silicone resin layer by laser light irradiation;
Removing the residue remaining in the opening of the silicone resin layer by blasting;
including,
A method for manufacturing an LED substrate.
The silicone resin layer is a solder resist,
The manufacturing method of the LED board of Claim 1 characterized by the above-mentioned.
Prior to the laser light irradiation, a protective film is formed on the silicone resin layer,
In the laser light irradiation, the laser light penetrates the protective film to form the opening in the silicone resin layer.
The manufacturing method of the LED board of Claim 1 or 2 characterized by the above-mentioned.
Removing the protective film after the blast treatment;
The manufacturing method of the LED board of Claim 3 characterized by the above-mentioned.
The residue includes silica (SiO 2 ),
The manufacturing method of the LED substrate as described in any one of Claims 1 thru | or 4 characterized by the above-mentioned.
The silicone resin layer covers the conductor layer before the laser light irradiation,
The conductor layer is exposed at the opening of the silicone resin layer by the laser light irradiation and the blast treatment.
The method for manufacturing an LED substrate according to claim 1, wherein:
The reflector particles are made of titanium oxide.
The manufacturing method of the LED substrate as described in any one of Claims 1 thru | or 6 characterized by the above-mentioned.
The titanium oxide is anatase type titanium oxide.
The manufacturing method of the LED board of Claim 7 characterized by the above-mentioned.
The silicone resin layer contains at least one of zirconia, alumina, and silica as the reflector particles.
The manufacturing method of the LED substrate as described in any one of Claims 1 thru | or 6 characterized by the above-mentioned.
The light source of the laser light is a CO 2 laser.
The method for manufacturing an LED substrate according to any one of claims 1 to 9, wherein:
The abrasive used for the blast treatment is water-soluble.
The manufacturing method of the LED substrate as described in any one of Claims 1 thru | or 10 characterized by the above-mentioned.
The average particle diameter of the abrasive grains used for the blast treatment is in the range of 0.1 to 200 μm.
The method for manufacturing an LED substrate according to claim 1, wherein:
The LED substrate is a blue LED or ultraviolet LED LED substrate,
The manufacturing method of the LED substrate as described in any one of Claims 1 thru | or 12 characterized by the above-mentioned.