JPH01223414A - Led packaging body for electronic device - Google Patents

Abstract

PURPOSE:To reduce the output of a light source, and also, to miniaturize and thin a packaging body by providing an electrode on the reverse side of a substrate on which an electronic device is formed, and attaching an LED chip to this electrode as one body with the substrate. CONSTITUTION:On the surface side of a substrate 1 made of transparent glass, liquid crystal elements 2 such as a liquid crystal display an a liquid crystal shutter, etc. are formed. On the other hand, on the reverse side of the substrate 1, an electrode 8 is provided, and to this electrode, an LED chip 7 is connected by a bump 10 and a solder bump 11 by a face-down bonding method. An emitted light 12 of the LED chip 7 transmits through the substrate 1 from the reverse side of the substrate 1 and irradiates the liquid crystal elements 2. Accordingly, by shortening a distance between the LED chip 7 being in irradiation light source and the surface to be irradiated by the beam the output of the light source is reduced, and also, since the chip 7 is provided as one body on the reverse side of the substrate, a packaging body can be miniaturized and thinned.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an LED (light emitting diode) package for illuminating electronic devices such as a rock crystal display, a liquid crystal shutter array, and a 1x sensor.

(Prior Art) A lighting device for an electronic device such as a liquid crystal display or a liquid crystal shutter array is assembled separately from the electronic device and attached to the electronic device.

Therefore, it is necessary to adjust the positional relationship between the electronic device and the lighting device. Because the electronic equipment and lighting equipment are separated, the lighting equipment requires high output power.Additionally, members such as substrates and support materials for the lighting equipment are required, which increases the number of parts.
It is difficult to make it smaller, thinner, and cheaper! It is.

(Objective) It is an object of the present invention to provide an LED mounting body for lighting an electronic device, which can reduce the output of a light source, and can also be made smaller and thinner by reducing the number of parts.

(Structure) The LED mounting body of the present invention is integrally mounted on the substrate of an electronic device to be illuminated.

That is, in the LED mounting body of the present invention, an electrode is provided on the back surface of a transparent glass substrate on which an electronic device is formed, and an LED chip is mounted on the electrode by a face-down bonding method, so that light emission from the LED chip is is taken out to the front side through the substrate.

Examples will be specifically described below.

FIG. 1 shows an example in which the present invention is applied to a liquid crystal display or a liquid crystal shirt.

1 is a transparent glass substrate. A liquid crystal element 2, which is a liquid crystal shutter or a liquid crystal display, is formed on the front side (lower side in the figure) of the substrate 1. The liquid crystal element 2 has a structure in which transparent electrodes 4 and 5 are provided with a liquid crystal layer 6 interposed between it and a transparent glass substrate 3 on the front side.

On the back side (upper side in the figure) of the substrate 1, a plurality of LED chips 7 for illumination are mounted in a direction perpendicular to the plane of the paper. An electrode 8 is formed on the back surface of the substrate 1 and covered with an insulating protective film 9. The electrode 8 is exposed at the portion where the LED chip 7 is connected, and the LED chip 7 is connected to the connection portion using bumps 10 and solder bumps 11 by face-down bonding.

In this embodiment, the light emission 12 of the LED chip 7 is caused by the substrate l.
Board from the back side! The light passes through and irradiates the liquid crystal element 2 on the front side.

FIG. 2 shows an embodiment in which the present invention is applied to a same-magnification sensor.

Reference numeral 20 denotes a transparent glass substrate, on the surface (upper side in the figure) of which a same-magnification sensor section 21 is formed. In the equal-magnification sensor section 21, a chromium (Cr) film 22 with a thickness of 0.1 μm P1 degree is formed on a substrate 20 and patterned, and an insulating film S i N 23 with a thickness of about 0.3 μm is formed on it. An amorphous silicon film 24 with a thickness of about 0.6 μm is formed and patterned on the insulating film 23, and an N+ film 24 with a thickness of about 0.2 μm is formed on the insulating film 23.
An amorphous silicon film 25 is formed and patterned. 26 is an aluminum electrode with a thickness of about 1.0 μm. As a result, the light receiving section 27. Storage capacitor 28 and thin film transistor 29
is configured.

A light receiving window 30 is opened adjacent to the light receiving section 27 and the substrate 20
The irradiation light can enter from the back side of the original 31, and the light receiving section 27 is provided with an opening for receiving the reflected light from the original 31.

32 is a surface protective film that protects the same-size sensor section 21;
On top of that is a thickness of 50 mm to protect it from sliding wear with the original 31.
A glass layer 33 having a thickness of approximately μm is provided.

A plurality of illumination LED chips 34 for illuminating the original 31 are mounted on the back surface (lower side in the figure) of the substrate 20 in a direction perpendicular to the plane of the paper. An electrode 35 is formed on the back surface of the substrate 2o and covered with an insulating protective film 36. LED chip 3
4, the LED chip 34 is connected to the exposed portion of the electrode 35 by bumps 37 and solder bumps 38.

In this embodiment, the light emitted 39 from the LED chip 34 passes through the substrate 20 from the back side of the substrate 20 and enters the document 31 on the front side, and the reflected light from the document 31 is received and detected by the light receiving section 27.

(Effects) In the present invention, the lighting LED chip is mounted on the back surface of the substrate on which the electronic device is formed by face-down bonding, so the distance between the LED chip as the lighting light source and the irradiated surface is shortened. This allows the output of the light source to be reduced.

By mounting the LED chip directly on the back side of the device's substrate, the entire device can be made thinner and smaller.
For example, if the thickness of the LED chip is about 300 μm, the height of the bump is about 10 μm, and the height of the solder bump is about 50 μm.

The overall thickness of the LED mounting body is reduced to about 360 μm.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are sectional views each showing an embodiment. l, 20... Glass substrate, 2... Liquid crystal element, 7.34... LED chip, 8.35... Electrode, 21...・・Same size sensor part.

Claims (1)

[Claims] (1) An electrode is provided on the back side of a transparent glass substrate on which an electronic device is formed, and an LED chip is mounted on the electrode by face-down bonding, and the light emitted from the LED chip passes through the substrate and reaches the front side. LED mounting body being taken out.