Manufacturing method of white semiconductor light- emitting device

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a method for manufacturing a white semiconductor light emitting device that converts a blue light emitting diode (LED) into a wavelength to emit white light.

【0002】

[Conventional technology]

In recent years, high-brightness blue-emitting LEDs using GaN-based compound semiconductors have been developed, and white-emitting semiconductor light-emitting devices have come to be manufactured by utilizing the high-luminance. This white light emitting semiconductor light emitting device emits white light by sealing the periphery of the blue light emitting light emitting element with a resin containing a fluorescent substance and converting the wavelength into yellowish green so as to have a complementary color relationship with blue by the fluorescent substance. Fig. 9 shows a conventional example of obtaining.

【0003】

The example shown is a surface mount type semiconductor light emitting device, in which a pair of electrodes 51 and 52 are formed on an insulating substrate 50, and a GaN-based compound semiconductor is laminated on one of the electrodes to emit blue light. The light emitting element 53 of the above is mounted, and the electrodes on the p side and the n side of the upper surface thereof are bonded to the electrodes 51 and 52 by the wires 54a and 54b. Then, a wavelength conversion layer 55 containing a fluorescent substance for wavelength conversion is formed by a precipitation method, and the wavelength conversion layer 55 is included and sealed with an epoxy resin package 56.

【0004】

In such a configuration, the light from the light emitting layer of the light emitting element 53 is mainly emitted upward, but the light is also emitted toward the side. Then, when passing through the wavelength conversion layer 55 laminated on the upper surface of the light emitting element 53 by the precipitation method, a part of the blue light emission excites a fluorescent substance to generate yellowish green, and the blue light emission and the yellowish green light emission are the resin package 56. Is emitted from.

【0005】

[Problems to be Solved by the Invention]

However, when the wavelength conversion layer 55 containing a fluorescent substance is formed by the precipitation method, although the layer thickness can be made uniform, the entire side surface of the light emitting element 53 cannot be covered as shown in the figure, and a part of the side surface cannot be covered. It will be exposed. In order to prevent this, the amount of precipitation may be increased so that the entire light emitting element 53 is filled, but the layer thickness of the wavelength conversion layer 55 covering the upper surface of the light emitting element 53, which is the main light extraction surface, becomes excessive, which is good. White light emission cannot be obtained.

【0006】

As described above, in the formation of the wavelength conversion layer 55 by the precipitation method, a part of the side surface of the light emitting element 53 is exposed, so that blue light emission is emitted from this side surface. For this reason, blue light is mixed with white light emitted from the main light extraction surface, and the color mixing property is lowered and the light distribution property is also poor. Therefore, a sufficiently pure white emission cannot be obtained.

【0007】

Further, the wavelength conversion layer can be formed by potting instead of the precipitation method. Since the resin containing the fluorescent substance is dropped by the dispenser to form the wavelength conversion layer by this potting, the layer thickness tends to be distributed as shown by the alternate long and short dash line in the figure. On the other hand, if the layer thickness of the wavelength conversion layer is not uniform, the wavelength conversion rate will differ depending on the location. That is, in the portion where the thickness of the wavelength conversion layer is thin, the wavelength conversion rate is lowered to produce bluish white light, and sufficiently pure white light emission cannot be obtained as in the case of the precipitation method.

【0008】

As described above, in the conventional manufacturing method, it is not possible to form a wavelength conversion layer having a uniform thickness around the light emitting element 53, the color mixing property and the light distribution property are poor, and good white light emission can be obtained. Can not.

【0009】

An object of the present invention is to provide a method for manufacturing a white semiconductor light emitting device capable of forming a wavelength conversion layer having a uniform thickness all around a light emitting element and obtaining pure white light emission.

【0010】

[Means for solving problems]

INDUSTRIAL APPLICABILITY The present invention includes a step of forming a bump electrode on an electrode pattern formed on a substrate material, a step of conducting a blue light emitting light emitting element as a flip tip type and conducting it on the electrode pattern via the bump electrode, and a step of conducting the light emitting element A step of covering the substrate material with a metal mask in a pattern that makes the distances from both end faces uniform, and a step of printing and forming a wavelength conversion resin containing a fluorescent substance by a screen printing method using the pattern of the metal mask. It is characterized by comprising a step of containing the wavelength conversion resin and sealing it with a resin package layer, and a step of dicing so as to include one light emitting element at a time.

【0011】

According to the present invention, it is possible to obtain a method for manufacturing a white semiconductor light emitting device capable of forming a wavelength conversion layer having a uniform thickness all around the light emitting element and obtaining pure white light emission.

【0012】

BEST MODE FOR CARRYING OUT THE INVENTION

The invention according to claim 1 is a step of forming a bump electrode on an electrode pattern formed on a substrate material, and a step of conductively mounting a blue light emitting element as a flip tip type on the electrode pattern via the bump electrode. A step of covering the substrate material with a metal mask in a pattern that makes the distances from both end surfaces of the light emitting element uniform, and printing a wavelength conversion resin containing a fluorescent substance by a screen printing method using the pattern of the metal mask. Manufacture of a white semiconductor light emitting device comprising a step of forming, a step of sealing with a resin package layer containing the wavelength conversion resin, and a step of dying so as to include one light emitting element at a time. It is a method and has an effect that a white semiconductor light emitting device that emits pure white light without mixing blue colors can be obtained.

【0013】

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

【0014】

1 to 6 are schematic views showing the manufacturing methods in this embodiment in order.

【0015】

FIG. 1 shows a process of forming electrode patterns 2 and 3 on an insulating substrate material 1 and forming bump electrodes 2a and 3a at predetermined positions of these electrode patterns 2 and 3 by a stud bump bonding method.

【0016】

FIG. 2 shows the process of electrically mounting the blue light emitting element 4 using the GaN-based compound semiconductor on the bump electrodes 2a and 3a in a flip-chip type. In this step, the electrodes on the p-side and n-side facing the lower surface side of the light emitting element 4 in the figure are aligned with and mounted on the bump electrodes 2a and 3a, and are mounted via the bump electrodes 2a and 3a by ultrasonic vibration and heating. The light emitting element 4 is conductively fixed to the electrode patterns 2 and 3.

【0017】

FIG. 3 shows a step of covering the substrate material 1 with the pattern of the metal mask 20 after the light emitting element 4 is electrically mounted. The pattern of the metal mask 20 is formed so that the distances from the left and right ends of the light emitting element 4 are equal, and the thickness thereof is such that the thickness of the wavelength conversion layer overlaid on the upper surface of the light emitting element 4 in a later process is sufficient for white wavelength conversion. It is a certain degree.

【0018】

After patterning of the metal mask 20, a fluorescent material for wavelength conversion from blue to white (eg (Y, Gd))₃(Al, Ga)₅O₁₂The wavelength conversion resin 21 mixed with: Ce etc. is preferable) is printed by a screen printing method. After this screen printing, when the pattern of the metal mask 20 is removed and cured, as shown in FIG. 4, the left and right end surfaces of the light emitting element 4 have a uniform wall thickness on the substrate material 1 and the electrode patterns 2 and 3. A layer of wavelength conversion resin 21 having the same distance from is formed.

【0019】

Next, a molding die (not shown) is placed on the substrate material 1 and epoxy is injected to form the package layer 22 as shown in FIG. The package layer 22 is formed so as to have a substantially trapezoidal vertical cross-sectional shape that covers the entire wavelength conversion resin 21.

【0020】

After the formation of the package layer 22, the white semiconductor light emitting device shown in FIG. 7 can be obtained as a product by dicing with the dicing 23 as shown in FIG.

【0021】

FIG. 8 is a vertical cross-sectional view showing the details of the manufactured white semiconductor light emitting device.

【0022】

As shown in the figure, the substrate material 1 becomes the substrate 5, the electrode patterns 2 and 3 become the electrodes 6 and 7, the wavelength conversion resin 21 becomes the wavelength conversion layer 8, and the package layer 22 becomes the resin package 9 by dicing. .. Since the wavelength conversion layer 8 is formed by the screen printing method using the metal mask 20 as shown in FIGS. 3 and 4, it covers the entire light emitting element 4 and its main light extraction surface (upper surface in the figure). ) Is uniform in layer thickness. Further, if the dicing interval is matched with the length of the wavelength conversion layer 8 in the left-right direction in FIG. 8, the circumference of the light emitting element 4 can be covered in all directions with the thickness in the left-right direction shown in FIG.

【0023】

As described above, in the present invention, since the circumference of the light emitting element 4 can be uniformly covered with the wavelength conversion layer 8, the wavelength of all the light from the main light extraction surface and the side of the light emitting element 4 can be uniformly converted. Therefore, pure white light emission can be obtained with high brightness without mixing blue light emission.

【0024】

[Effect of the invention]

In the present invention, since the wavelength conversion layer can be formed around the light emitting element with a substantially uniform wall thickness, it is possible to obtain a white semiconductor light emitting device capable of high-luminance white light emission without color mixing of blue light emission.

[Simple explanation of drawings]

[Figure 1]

It is a step of forming a bump electrode on an electrode pattern formed on a substrate material, and (a) is a plan view. (b) is a vertical cross-sectional view of (a) taken from the AA line. [Figure 2]

It is a process of mounting and mounting a light emitting element via a bump electrode, and (a) a plan view. (b) is a vertical sectional view [Fig. 3]

The process of covering the metal mask after mounting the light emitting element, (a) is a plan view. (b) is a vertical sectional view [Fig. 4]

It is a process of forming a wavelength conversion resin by a screen printing method using a metal mask pattern, and (a) is a plan view after printing. (b) is a vertical sectional view [Fig. 5]

It is a step of forming an epoxy package layer after forming a wavelength conversion resin, and (a) is a plan view. (b) is a vertical sectional view [Fig. 6]

Plan view showing a dicing process after forming a package layer [Fig. 7]

External perspective view of the white semiconductor light emitting device obtained by the dicing process. [Fig. 8]

Longitudinal sectional view of the white semiconductor light emitting device obtained by the manufacturing method of the present invention. [Fig. 9]

Longitudinal sectional view of a white semiconductor light emitting device by a conventional manufacturing method [Explanation of symbols]

1 Board material 2,3 electrode pattern 2a, 3a bump electrode 4 light emitting element 5 board 6,7 electrodes 8 wavelength conversion layer 9 Resin package 20 metal mask 21 Wavelength conversion resin 22 Package layer 23 Dicer