JP2001078298A - Microphone using light signal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need for a setting margin and to increase the degree of integration in a substrate by sealing a light emitting element and a photodetector with transparent resin, inserting a light nontransmissive material into a groove formed at the prescribed position sealing part between both the elements, and adhering them together with the transparent resin. SOLUTION: On a substrate such as a printed board, an LED, etc., as a light emitting element and a photodiode, etc., as a photodetector are mounted by die bonding or wire bonding. Those are sealed with transparent resin such as epoxy and a groove of e.g. about 50 μm in width is formed in the sealing part between the light emitting element and photodetector by a device such as a dicing saw and a wire saw. A light nontransmissive material such as metallic foil or resin foil is inserted into the groove and sealed with transparent resin such as epoxy. In this process, positioning is done only once when the groove is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The microphone of the present invention
It is used in the field of small microphones used in car phones and mobile phones, and in the field of intruder detection utilizing pressure changes by intruders.

[0002]

2. Description of the Related Art A microphone using an optical signal seals a light emitting / receiving element mounted on a substrate with a transparent resin,
A light-impermeable film is provided between the light-emitting and light-receiving elements in the sealing portion. A light non-transmissive film is formed on the outer wall of the transparent resin sealing portion other than a region serving as a light emitting portion and a light receiving portion. Light emitting part,
A light-reflective membrane vibrating due to sound, pressure, or the like is held above the light-receiving portion by a membrane support. Light from the light emitting element is emitted from the light emitting part and reaches the light receiving element from the light receiving part. The portions other than the light emitting portion / light receiving portion and the membrane support are made low in height so that the vibration of the membrane is not hindered by air viscosity. When the membrane position moves due to the vibration, the reflection position also moves, and the output of the light receiving element changes. The principle of a microphone using an optical signal is to detect sound, pressure, and the like by reading this output. As described in Japanese Patent Application No. 10-107427, the light-impermeable film between the light-emitting and light-receiving elements is formed by sealing the light-emitting element and the light-receiving element mounted on the substrate with a transparent resin, and forming the sealing portion. The step of cutting including the substrate, and the step of forming a light-impermeable film on at least one cut surface,
Thereafter, a step of bonding and integrating the cut surface of the light emitting element sealing portion and the light receiving element sealing portion is performed.
The film is formed on the cut surface by vapor deposition or the like. This film is for preventing the generation of a bias component that does not depend on the membrane vibration due to the light from the light emitting element directly reaching the light receiving element.

[0003]

The prior art has the disadvantage that it requires a margin for setting during the bonding and integration process, and is expensive due to the low degree of integration in the substrate. In addition, a transparent resin sealing section cutting step, a step of bonding and integrating the light emitting element sealing section and the light receiving element sealing section, and a positioning operation in two times are necessary, and the steps are complicated.

[0004]

A light-emitting element and a light-receiving element are mounted on a substrate, and the light-emitting element and the light-receiving element are sealed with a transparent resin. A groove is formed in a sealing portion at a predetermined position between the light-emitting and light-receiving elements. And insert it with a transparent resin.

[0005]

DETAILED DESCRIPTION OF THE INVENTION An LED is mounted on a substrate such as a printed circuit board.
Etc. as light emitting elements, photodiodes etc. as light receiving elements,
Die-bonding and wire-bonding work is performed. These are sealed with a transparent resin such as epoxy.
A groove is formed in a sealing portion between the light emitting and light receiving elements by using a device such as a dicing saw or a wire saw. Metal foil in this groove,
A light-impermeable material such as a resin foil is inserted and sealed with a transparent resin such as epoxy.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Die bonding and wire bonding are carried out on a substrate such as a printed circuit board by using an LED or the like as a light emitting element and a photodiode or the like as a light receiving element. Light-emitting / light-receiving elements are also installed in the area where there is a margin for the conventional adhesive integrated setting to increase the degree of integration. The mounted light-emitting and light-receiving elements are sealed with a transparent resin such as epoxy. Next, a groove is formed at a predetermined position of the light-emitting / light-receiving element sealing portion using a device such as a dicing saw or a wire saw. In FIG. 1 showing the embodiment, the groove extends to the inside of the substrate, but this is for facilitating fixing of the foil, and does not necessarily need to reach to the inside of the substrate. When forming the groove, an alignment operation is performed. The groove width is determined by the thickness of the dicing saw blade or the diameter of the wire saw wire, and a groove having a width of about 50 μm can be easily formed. A light-impermeable material such as a metal foil or a resin foil is inserted into the groove, and sealed with a transparent resin such as epoxy. For example, as the metal foil, a stainless steel foil having a thickness of 10 μm or the like is commercially available and easily available. In addition, as is apparent from the above, the positioning operation in this step is performed only once when forming the groove.

[0007]

According to the present invention, the setting margin in the conventional bonding and integrating process is not required, and the degree of integration in the substrate is increased. In addition, the positioning operation is performed twice, but is performed once, thereby simplifying the process.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a microphone using an optical signal according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Light-emitting element 2 Light-receiving element 3 Substrate 4 Membrane support 5 Membrane 6 Light-impermeable material 7 Light-emitting part 8 Light-receiving part 9 Transparent resin 10 Groove 11 Light-impermeable film

 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Alexander Palitsky O-Ida, Israel 60252 Oh. Box 323 Phone-Oars Limited (72) Inventor Alexander Kotz O-Ida, Israel 60252 Oh. Box 323 Phone-OR Limited F-term (reference) 5D021 DD04

Claims (1)

[Claims] 1. A light-emitting element, a light-receiving element, a substrate on which these are mounted, and a microphone using an optical signal composed of a membrane, wherein the light-emitting element and the light-receiving element mounted on the substrate are sealed with a transparent resin to emit light. A method of manufacturing a microphone using an optical signal, wherein a groove is formed in a sealing portion between light receiving elements, a light-impermeable material is inserted into the groove, and the light-transmitting material is adhered with a transparent resin.