JPS5919338B2 - semiconductor light emitting display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in semiconductor light emitting display devices for displaying numbers and characters, and particularly to the structure of a light reflector as a component of the device.

In general, numeric and character display devices using compound semiconductor light emitting elements such as GaP and GaAsP are widely used in transceivers, clock calculators, and the like.

The structure of this numerical display and character display device is shown in FIGS. 1a and 1b. Semiconductor light emitting element pellets 2 are formed by conductive resin, solder brazing material, etc. on a stem substrate 1 which has conductor wiring on a ceramic or glass epoxy substrate. A plurality of (in the example shown in the figure, eight pieces are attached along the Japanese letters) are fixed, and the pellet 2 and the stem 1 are further connected with a thin metal wire (AuAl) of 25 to 30 φμ.

A light reflector 3, which serves both to form characters and improve brightness, is combined with the mounted and bonded stem substrate 1. This light reflection is caused by white noryl resin, A-B-S (acrylonitrile butadiene) resin, which has good light reflectance, and Au, A
As shown in FIG. 2, the guide pin 13 protruding from the back surface and the concave portion on the surface of the stem are combined into one body. Also, the number shape 8 on the surface
A light path is formed inside along the letters. As shown in FIG. 1b, the light emitted from the light emitting element 2 travels while being reflected by the curve of this internal passage and is emitted along the figure 8 line on the surface. (Dotted line part) Next, this and the light scattering film 4 are sequentially placed in a case 5 made of a light-transmitting resin (acrylic resin, etc.) in order to make the luminescence distribution uniform. 5 is fixed with a sealing resin 6 to form a product.

This sealing resin 6 generally has a viscosity of 3000 to 1000.
Epoxy resin with 0 CPS is used. Here, the light reflector 3 conventionally has a rectangular parallelepiped shape as shown in FIG. 2, and its dimensions are about 0.3 to 0.571 m smaller than the inner dimensions of the case 5 due to the positioning of the device mentioned above. It is well established. Therefore, as shown in FIG. 3, the inner wall of the case 5 and the light reflector 3
Because the side walls of the film 4 and the case 5 are close to each other, a capillary phenomenon occurs when the sealing resin 6 is fixed, and the resin 6 tends to flow into the case 5. In some cases, the injected resin may flow between the surface film 4 and the case 5. There was a drawback that characters and numbers were mixed in between and became incomplete. In addition, since the surface of the guide pin is in full contact with the surface of the stem 1, as shown in FIG. The light reflector 3 tends to float due to the protrusions of about 0.1 to 0.5 height, which also has the drawback of easily causing light leakage from the sides and characters. If the distance between the light reflector and the stem is 50μ or more, side leakage of light will occur. In practice, these defects caused 5 to 10% of defective products and were a major problem in manufacturing. The present invention aims to eliminate these drawbacks in a simple manner.

Therefore, as shown in FIG. 7, the present invention solves the problem of capillary phenomenon without changing the width of the gap between the light reflector and the inner wall of the case by creating a certain space 14 along the path where the sealing resin flows. It is intended to provide

This is because when the sealing resin that has flowed in due to capillary phenomenon reaches this space 14, the capillary phenomenon is weakened and stopped due to the surface tension phenomenon, and the resin is drawn into this space and remains there. This is for the purpose of Furthermore, as shown in Figure 6, the above space is filled with the internal head of the external terminal lead (0.1
It is also used as an escape for the WI-0.57H11 container).

Therefore, in the present invention, in order to easily obtain the above-mentioned space at the part where the case, stem, and light reflector contact each other without changing the structure of the device, a light reflector having a protruding guide pin as shown in FIG. The peripheral corner of the surface that contacts the stem surface of the body is formed into a stepped shape 14.

The height and width of each step 14 is 171i1! t is sufficient, and these values can be made sufficiently small depending on the viscosity of the resin used for sealing and the size of the device.

In addition, if the step 14 is formed on the top surface of the light reflector where the S-shape is formed, as shown in FIG. 5, the flow of the sealing resin can be doubly prevented and the process of assembling the device can be prevented. It can serve as a guide during the work of storing the device in the case, and solves problems when automating device assembly.

This is because, as mentioned above, the space between the inner wall of the case and the light reflector is approximately 0.3 to 0.51g1t, so
A high degree of precision was required to prevent machine misalignment. In this way, the present invention prevents the flow of the sealing resin and prevents stains on the display device without changing the distance between the case and the light reflector to prevent light leakage due to misalignment of the light reflector. In fact, the defect rate due to this can be suppressed to 1% or less, and the light reflector is prevented from floating due to the head of the external terminal, and light leakage is prevented, which has the effect of increasing the brightness of the entire device.

[Brief explanation of the drawing]

FIG. 1a is a block diagram of a semiconductor light emitting display device, and FIG. 1b is an assembled sectional view thereof. FIG. 2 is a diagram showing a conventional light reflector. FIG. 3 is a diagram showing conventional resin sealing. FIG. 4 and FIG. 5 are diagrams showing the light reflector of the present invention. FIG. 6 is a diagram showing resin sealing according to the present invention. FIG. 7 is a diagram showing the principle of the present invention. 1... Stem, 2...
Semiconductor light emitting device pellet, 3... Light reflector, 4
...Light scattering film, 5...Case,
6... Resin body for sealing, 7... External terminal.

Claims (1)

[Claims] 1 A stem 1 on which a semiconductor light emitting element pellet 2 is mounted and bonded, and a translucent case 5 that covers this, and a resin seal 6 is formed between the back surface of the stem 1 and the case 5.
A semiconductor light emitting display device in which a light reflector 3 having a stepped shape 14 at its periphery is housed inside the display device.