JPH10209505A - Light emitting diode and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the cost from increasing by forming a fluorescent layer on the wafer and enabling the increase of man-hour required for forming the fluorescent layer to be substantially ignored. SOLUTION: A light emitting diode 1 is manufactured by forming a chip 2 as a one-face terminal type chip provided with positive and negative electrodes on one face, adhesively forming a fluorescent layer 3 on the light emitting face in a film-shape when the chip 2 is at the stage of wafer, and by cutting the wafer into individual chips 2. Since the fluorescent layer 3 is formed at the stage of wafer, the increase of man-hour for forming the fluorescent layer 3 can be substantially ignored.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting diode, and more particularly, to a light emitting diode provided with a fluorescent layer before light emitted from a chip passes through a case and is emitted to the outside. The present invention relates to a light-emitting diode configured to convert a light-emission color by using a light-emitting diode.

[0002]

2. Description of the Related Art FIGS. 5 to 7 show examples of the structure of a conventional light emitting diode of this type. First, a light emitting diode 90 shown in FIG. That is, the entire case 91 is formed of the fluorescent layer 92. Therefore, the light emitted from the chip 10 is converted into a luminescent color while passing through the case 91.

In a light emitting diode 80 shown in FIG. 6, a cap 81 is formed in advance with a resin to which a fluorescent substance 92a is added.
Is sealed with a transparent resin to form a case 82.
Therefore, the conversion of the emission color is performed at the cap 81.

A light emitting diode 70 shown in FIG.
First, the periphery of the chip 10 is sealed with a resin to which the fluorescent substance 92a is added to form a fluorescent layer 71, and the chip 10 covered with the fluorescent layer 71 is sealed again with a transparent resin. Thus, the light from the chip 10 has a desired color when the light from the chip 10 has passed through the fluorescent layer 71.

[0005]

However, in the conventional light emitting diode described above, first, in the light emitting diode 90 shown in FIG.
By adding a, the light emission by the fluorescent substance 92a is also performed over the entire case 91, and as a result, the light emission is performed in a diffused state, and the required amount of light in the front direction is reduced. This causes a problem of drastic reduction.

Further, in the light emitting diode 80 shown in FIG. 6, light emission by the fluorescent substance 92a is performed only in the cap 81, and diffusion does not occur in the case 82 before reaching the cap 81. Although the problem of the decrease in the amount of light is somewhat improved, it is still not sufficient, and the problem of insufficient performance still occurs. In addition, a process of producing the cap 81 is required in advance, and the problem of cost increase due to an increase in the number of processes. Points also occur.

In the light-emitting diode 70 shown in FIG. 7, the area of light emission by the fluorescent substance 92a is certainly small, and the problem of the amount of light in the front direction can be almost solved. The forming process is also the case 7
Since the step of forming 2 is also performed by a casting mold, a curing treatment such as heating is required in each step, which causes a problem that the step is complicated and costs are increased, and a residence time in the step is also reduced. There is also a problem that the length is increased and the productivity is reduced, and solving these points is an issue.

[0008]

According to the present invention, as a specific means for solving the above-mentioned conventional problems, a fluorescent layer is provided in an optical path until light emitted from a chip is emitted from a case to the outside. In the method for manufacturing a light emitting diode provided, the chip is formed as a one-sided terminal type provided with positive and negative electrodes on one surface, and the fluorescent layer is formed by coating a fluorescent layer on a light emitting surface when the chip is in a wafer state. An object of the present invention is to solve the problem by providing a method for manufacturing a light-emitting diode, in which a chip is formed in close contact with a surface and then cut into individual chips.

[0009]

Next, the present invention will be described in detail based on an embodiment shown in the drawings. 1 to 3 show a method of manufacturing a chip 2 which is a main part of a method of manufacturing a light-emitting diode 1 according to the present invention in the order of steps. First, as shown in FIG. The P layer is diffused at a plurality of locations in the form of a matrix in the vertical and horizontal directions, and the light emitting unit 2
a is formed, and the positive electrode 2b and the negative electrode 2c are both one-sided terminal types provided on one surface.

Normally, in this state, the wafer 2A is cut and the light emitting portions 2a are separated into chips 2. In the present invention, the fluorescent material 3a is removed before the cutting step as shown in FIG. The step of forming the fluorescent layer 3 is performed. At this time, the fluorescent layer 3 includes the positive electrode 2b and the negative electrode 2b.
The light emitting surface 2d is provided on the other surface having a front-back relationship with the one surface on which the light emitting device c is provided, that is, on the light emitting surface 2d.

The means for providing the fluorescent layer 3 at this time may be spray coating, spin coating, or vacuum deposition of the fluorescent substance 3a in a solution state with a binder and a solvent. Means may be employed, in other words, it is only necessary that the film is formed as a film surface having a substantially uniform thickness on the emission surface 2d and has an appropriate adhesive force and is in close contact with the wafer 2A.

The wafer 2A on which the fluorescent layer 3 is formed as described above is cut as shown in FIG. 3, and the light emitting portions 2a are separated into individual chips 2. Then, the chip 2 is mounted on, for example, a lead frame 4 and sealed with a transparent resin to form a case 5, and as shown in FIG.
Is obtained.

Next, the operation and effect of the light emitting diode 1 of the present invention having the above-described configuration will be described. First, in the present invention, since the fluorescent layer 3 is formed in a step different from the formation of the case 5, the number of steps for forming the fluorescent layer 3 is certainly added. However, in the present invention, the wafer 2A
Therefore, the working time per one chip 2 becomes very short, and it is possible to substantially prevent the cost from increasing.

Second, since the fluorescent layer 3 is formed in close contact with the emission surface 2d of the chip 2, the function of converting the emission color by the emission of fluorescent light is also within the range of the fluorescent layer 3, that is, Within the area of the exit surface 2d and the chip 2
Is performed at a position very close to.

Therefore, the light emitting area and the light emitting position when the fluorescent layer 3 is provided hardly change from the light emitting area and the light emitting position when the fluorescent layer 3 is not provided. In the conventional case 5 in which the shape is determined so as to obtain the optimum light distribution characteristics based on the position and the light emitting area, the optimum light distribution characteristics can be obtained with the fluorescent layer 3 provided. Irrespective of the presence or absence of the fluorescent layer 3, the same shape can be obtained, and standards can be standardized.

[0016]

As described above, according to the present invention, according to the present invention, a chip is formed as a one-sided terminal type provided with positive and negative electrodes on one surface, and the fluorescent layer is formed on the light emitting surface when the chip is in a wafer state. The method of manufacturing a light emitting diode in which a layer is formed in close contact with a film surface and then cut into individual chips is adopted.First, a fluorescent layer is formed in a wafer state. In addition, it is possible to achieve an extremely excellent effect of preventing an increase in cost by making the increase in the number of steps for forming the fluorescent layer substantially negligible.

Second, since the fluorescent layer is formed in close contact with the emitting surface of the chip 2 as described above, an increase in the light emitting area and a shift in the light emitting position due to the provision of the fluorescent layer can be prevented. As a result, it is possible to obtain the same optimum light distribution characteristics as in the case where the fluorescent layer is not provided even in the conventional case. Is played. In addition, the fact that the case may have the same shape as that of the conventional case also ensures compatibility and the like, and enables standardization and the like in standards.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a diffusion step in an embodiment of a method for manufacturing a light emitting diode according to the present invention.

FIG. 2 is a cross-sectional view illustrating a process of forming a fluorescent layer according to the same embodiment.

FIG. 3 is a cross-sectional view showing a wafer cutting step of the same embodiment.

FIG. 4 is a sectional view showing an embodiment of a light emitting diode according to the present invention.

FIG. 5 is a sectional view showing a conventional example.

FIG. 6 is a sectional view showing another conventional example.

FIG. 7 is a sectional view showing still another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Light emitting diode 2 ... Chip 2a ... Light emitting part 2b ... Positive electrode 2c ... Negative electrode 2d ... Emission surface 2A ... Wafer 3 ... Fluorescent layer 3a ... Fluorescent substance 4 ... Lead frame 5 ... …Case

Claims (2)

[Claims] 1. A method for manufacturing a light-emitting diode, comprising a fluorescent layer provided in an optical path until light emitted from a chip is emitted from a case to the outside, wherein the chip is provided with positive and negative electrodes on one surface. The fluorescent layer is formed as a one-sided terminal type, and the fluorescent layer is formed in such a manner that the fluorescent layer is in close contact with the light emitting surface in the state of a wafer in a wafer state, and then cut into individual chips. A method for manufacturing a light emitting diode. 2. A light-emitting diode in which a fluorescent layer is provided in an optical path until light emitted from a chip is emitted from a case to the outside, wherein the chip has a one-surface terminal type provided with positive and negative electrodes on one surface. A light-emitting diode, wherein the fluorescent layer is a chip which is previously formed in a wafer state on a light emitting surface in close contact with a film surface.