JP2007108542A - Optical fiber module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical fiber module that is free from light leak and highly reliable. <P>SOLUTION: The optical fiber module 1 covered with a shield case 2 is formed by joining a housing 5 being a resin formed product to a light receiving/emitting device 4. On one face of the housing 5, recesses 5a, 5b in which the mounting part of a light receiving/emitting element is housed are formed, while, on the opposite face, an insertion port 5c to/from which an optical fiber 3 can be inserted/extracted is formed. Between the recesses 5a, 5b, there is formed a partition wall 5f for separating the two recesses. Through holes 6a which are a plurality of external connecting electrodes are formed on one side face of a wiring board 6 composed of glass epoxy resin or the like. An LED 7 and a light emitting IC 8 as well as a PDi 9 and a light receiving IC 10 are mounted on the same wiring board 6 and sealed with a light transmitting sealing resin 11. A groove 6b is formed between the light emitting element and the light receiving element on the wiring board 6. A part of the partition wall 5f, forming a projected part 5g and projecting from the joining face with the wiring board 6 of the housing 5, is fitted to the groove 6b. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical fiber module which is a transmission / reception device using an optical fiber.

  The optical fiber is thin (about 0.1 mm in diameter), lightweight (the specific gravity of glass is about 1/4 of the specific gravity of copper), excellent in flexibility (with a radius of curvature of several centimeters or less), not subjected to electromagnetic induction, Because it has strong features such as crosstalk, low loss (for example, 1 dB / km) and high-bandwidth transmission, and few resource problems, transmission systems using optical fiber cables are used not only in the WAN area, which is a field of public communication. It has a wide range of application fields, such as a transmission system with internal configuration called a LAN, a data bus, a data link, and various measurement control systems.

In addition, mainly in Europe, MOST (Media Oriented)
An in-vehicle network standard called Systems Transport) has been adopted. This provides an environment in which navigation systems and other intelligence functions such as audio and telephone can be connected to each other. In this case, a two-core bidirectional optical fiber module that uses two POFs (Plastic Optical Fibers) for data communication is used (for example, see Non-Patent Document 1). In addition, with respect to such an in-vehicle optical fiber module, a demand for lead-free solder bonding has become essential.

  Under such circumstances, the applicant of the present application has applied for a highly reliable optical fiber module in which the lead terminals are improved to a surface mounting type capable of lead-free reflow when mounted on a motherboard (Patent Document 1). reference). FIG. 3 is a partial sectional bottom view of a conventional optical fiber module. Reference numeral 51 denotes a surface-mounting optical fiber module (light emitting / receiving module) that houses a light emitting / receiving device, which will be described later, in a housing and performs a bidirectional optical transmission function. Reference numeral 2 denotes a shield case covering the optical fiber module 51. Ribs 2a for positioning and holding the optical fiber module 1 are cut and raised on the side and back of the shield case 2. Reference numeral 3 denotes an optical fiber, into which a plug portion 3b having an engagement pin 3a is fitted at the tip.

  Further, the configuration of the optical fiber module 51 will be described. Reference numeral 4 denotes a light emitting / receiving device in which a light emitting element and a light receiving element are mounted on the same wiring board. Reference numeral 5 denotes a housing which is a resin molded product joined to the light emitting / receiving device 4. The housing 5 is formed with recesses 5a and 5b which are recesses in which the mounting portions of the light emitting and receiving elements are accommodated, and an insertion port 5c into which the insertion portion 3b of the optical fiber 3 can be inserted and removed, and leads to the recesses 5a and 5b. Yes. The insertion portion 5c is formed with an insertion groove 5e into which the engagement pin 3a is inserted, and an arcuate groove portion 5d communicating with the insertion groove 5e, and the engagement pin 3a engages with the groove portion 5d so that an optical fiber is formed. 3 is prevented from falling off.

  Reference numeral 6 denotes a wiring board made of glass epoxy resin or the like, and a plurality of through holes 6a as external connection electrodes are formed on one side surface thereof. The end surface of the through hole 6a is exposed flush with the bottom surface of the shield case 2 having the opening. Reference numeral 7 denotes a light emitting diode (LED) which is a light emitting element that converts a modulated electric signal into an optical signal. Reference numeral 8 denotes a light emitting IC that converts a logic level electric signal into a light emitting element driving signal. 6 is mounted and wired.

Reference numeral 9 denotes a photodiode (PDi) that is a light receiving element that converts an optical signal into an electric signal, and reference numeral 10 denotes a light receiving IC that converts the optical signal received by the PDi 9 into an electric signal and further amplifies it to a logic level. Both are mounted on the wiring board 6 and wired. Reference numeral 11 denotes a sealing resin that seals the LED 7 and the light emitting IC 8, the PDi 9 and the light receiving IC 10, and transmits visible light.
Overview of MOST, Nikkei Electronics, Japan, Nikkei Business Publications, April 19, 1999, No. 741, p. 108-121 Japanese Patent Application No. 2004-118380 (unpublished)

  However, in such a conventional optical fiber module, while improving the light receiving sensitivity on the receiving side, light on the transmitting side leaks to the light receiving side from a slight gap in the joint surface between the light receiving and emitting device and the housing. There was a problem that the receiving side malfunctioned.

  The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a highly reliable optical fiber module that eliminates light leakage from the light emitting unit to the light receiving unit. is there.

  The means of the present invention for achieving the above-described object is to mount a light emitting / receiving device by mounting a light emitting element and a light receiving element that transmit and receive an optical signal by an optical fiber on the same wiring board provided with an external connection electrode on one side surface. In the optical fiber module formed by joining the light emitting / receiving device to a housing provided with a recess for housing the light receiving / emitting device and an insertion port through which the optical fiber can be inserted / removed, the recess of the housing A partition wall is provided between the light emitting element and the light receiving element, and a part of the wall surface is fitted into a groove provided on the wiring board.

  According to the present invention, a light emitting element and a light receiving element that transmit and receive an optical signal using an optical fiber are mounted on the same wiring board provided with an external connection electrode on one side surface to form a light receiving and emitting device. In the optical fiber module formed by joining the light emitting / receiving device to a housing provided with a recess for housing the optical fiber and an insertion port through which the optical fiber can be inserted and removed, the light emitting element and the light receiving element are provided in the recess of the housing. A partition wall is provided to block the gap, and a part of this wall is inserted into the groove provided on the wiring board. It is possible to provide a highly reliable optical fiber module that sometimes does not malfunction.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a partial sectional bottom view of an optical fiber module which is an embodiment of the present invention. FIG. 2 is an exploded perspective view of the optical fiber module. First, the structure of the optical fiber module which is embodiment of this invention is demonstrated.

  In FIG. 1, reference numeral 1 denotes a surface-mounting optical fiber module (light emitting / receiving module) that houses a light emitting / receiving device (to be described later) in a housing and performs a bidirectional optical transmission function. A partition wall 5f is formed between the light-emitting side recess 5a and the light-receiving side recess 5b, which is a recess for housing the mounting portion of the light emitting / receiving device 4 provided in the housing 5. A part of the partition wall 5f protrudes outward from the joint surface with the wiring substrate 6 to form a protrusion 5g. A groove 6b is formed on the upper surface of the wiring board 6 between the light emitting element mounting part and the light receiving element mounting part. The protruding portion 5g is fitted into the groove 6b. Since other configurations are substantially the same as those of the conventional optical fiber module 51, the same components are denoted by the same reference numerals and names, and detailed description thereof is omitted.

  Next, effects of the embodiment of the present invention will be described. A partition wall 5f is provided between the recesses 5a and 5b of the housing 5, and a part of the partition wall 5f serves as a protrusion 5g and is fitted into a groove 6b provided on the wiring board 6. Therefore, light leakage from the light emitting part to the light receiving part can be eliminated. Therefore, the optical fiber module 1 is a highly reliable optical fiber module without malfunction during data transmission.

  The optical fiber module of the present invention is applied for intra-office communication or in-vehicle audio data communication.

It is a partial section bottom view of the optical fiber module which is an embodiment of the invention. 1 is an exploded perspective view of an optical fiber module according to an embodiment of the present invention. It is a fragmentary sectional bottom view of the conventional optical fiber module.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical fiber module 3 Optical fiber 4 Light emitting / receiving device 5 Housing 5a, 5b Recessed part 5c Insertion port 5f Partition 5g Projection part 6 Wiring board 6a Through hole 6b Groove part 7 LED
8 Light emitting IC
9 PDi
10 Light receiving IC

Claims (1)

A light-emitting element and a light-receiving element that transmit and receive an optical signal using an optical fiber are mounted on the same wiring board provided with an external connection electrode on one side surface to form a light-receiving / emitting device, and a recess that houses the light-receiving / emitting device; In the optical fiber module in which the light receiving and emitting device is joined to a housing provided with an insertion port through which an optical fiber can be inserted and removed, a partition that blocks between the light emitting element and the light receiving element is formed in the concave portion of the housing. An optical fiber module, wherein a part of the wall surface is fitted in a groove provided on the wiring board.

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