JP2008294339A - Optical communication module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical communication module capable of being thinned and preventing damages. <P>SOLUTION: An infrared data communication module A includes a substrate 1, a light emitting element 2, a light receiving element 3, a resin package 5 covering the light emitting element 2 and the light receiving element 3, and a shield cover 6. The shield cover 6 is provided with a top plate 61 covering a center part 5c positioned between two lenses 5a and 5b of the resin package 5, and a spring part 62 extending from the top plate 61 and generating elastic force when the top plate 61 is brought close to the resin package 5. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical communication module.

  As an optical communication module capable of bidirectional communication by including a light emitting element and a light receiving element, for example, there is an IrDA compliant infrared data communication module. Such infrared data communication modules are widely used in notebook personal computers, portable telephones, electronic notebooks, and the like.

  An example of a conventional infrared data communication module is shown in FIG. The infrared data communication module X includes a light emitting element 92, a light receiving element 93, and a drive IC 94 mounted on a substrate 91. The light emitting element 92, the light receiving element 93, and the driving IC 94 are covered with a resin package 95. In the resin package 95, a lens 95a positioned in front of the light emitting element 91 and a lens 95b positioned in front of the light receiving element 93 are formed. The resin package 95 is covered with a shield cover 96. The shield cover 96 is for preventing the driving IC 94 for driving control of the light emitting element 92 and the light receiving element 93 from receiving external electromagnetic noise and visible light.

  Notebook PCs, portable telephones, electronic notebooks and the like on which the infrared data communication module X is mounted are always required to be miniaturized. For this reason, there is a strong demand for thinning the infrared data communication module. If the thickness of the substrate 91 and the resin package 95 is reduced, the risk of damage to the infrared data communication module X increases. For example, when manufacturing the infrared data communication module X, if an excessive force is applied to the resin package 95 in the process of covering the resin package 95 with the shield cover 96, the drive IC 94 is broken or a wire for conduction (illustrated). (Omitted) may break. Moreover, there is a concern that such breakage and disconnection may occur in the work of mounting the infrared data communication module X on a circuit board or the like.

JP 2004-335881 A

  The present invention has been conceived under the circumstances described above, and an object of the present invention is to provide an optical communication module that can be thinned and prevented from being damaged.

  In order to solve the above problems, the present invention takes the following technical means.

  An optical communication module provided by the present invention includes a substrate, a light emitting element and a light receiving element mounted on the substrate at a distance from each other, and two lenses formed on the front surfaces of the light emitting element and the light receiving element, respectively. And an optical communication module comprising: a resin package that covers the light emitting element and the light receiving element; and a shield cover for electromagnetic shielding and light shielding of the light emitting element and the light receiving element. A top plate that covers a central portion located between the two lenses in the resin package, and one or more that extend from the top plate and generate an elastic force when the top plate is brought close to the resin package The spring portion is provided.

  According to such a structure, when attaching the said shield cover to the said resin package, the said spring part functions as a buffer part. For this reason, it is suitable for making the said center part of the said resin package thin. Moreover, the thinner the resin package, the smaller the thermal stress generated after the formation. As a result, the substrate can be thinned. Therefore, it is possible to reduce the thickness and prevent damage to the optical communication module.

  In a preferred embodiment of the present invention, the shield cover has two spring portions that are separated from each other, and is surrounded by the two spring portions, the top plate, and the central portion of the resin package. An adhesive that joins the shield cover and the resin package is provided in the space. According to such a configuration, when a force for bending the optical communication module is applied, the adhesive plays a role of reducing stress generated by the force. This is advantageous in reducing the thickness of the optical communication module and preventing damage.

  Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

  1 to 4 show an example of an infrared data communication module according to the present invention. The infrared data communication module A of the present embodiment includes a substrate 1, a light emitting element 2, a light receiving element 3, a driving IC 4, a resin package 5, and a shield cover 6.

  The board | substrate 1 consists of glass epoxy, for example, and is formed in planar view long rectangular shape as a whole. In the present embodiment, the substrate 1 is formed in an extremely thin shape with a thickness of 0.16 mm while a longitudinal dimension is 6.4 mm and a lateral dimension is 1.35 mm. A plurality of terminals 11 are formed on the side surface of the substrate 1. The plurality of terminals 11 are used for surface mounting the infrared data communication module A on a circuit board or the like, and are electrically connected to the light emitting element 2, the light receiving element 3, and the driving IC 4.

  The light emitting element 2 is made of, for example, an infrared light emitting diode capable of emitting infrared light. The light receiving element 3 is composed of, for example, a PIN photodiode capable of sensing infrared rays. The drive IC 4 is for controlling transmission / reception operations by the light emitting element 2 and the light receiving element 3. The light emitting element 2, the light receiving element 3, and the driving IC 4 are arranged in series in the longitudinal direction of the substrate 1, and the light emitting element 2 and the light receiving element 3 are located near both ends of the substrate 1.

  The resin package 5 is formed of, for example, an epoxy resin containing a dye and has no translucency for visible light, but has translucency for infrared rays. The resin package 5 is formed by a transfer molding method or the like, and is provided on the substrate 1 so as to cover the light emitting element 2, the light receiving element 3, and the driving IC 4. Two lenses 5 a and 5 b are integrally formed in the resin package 5. The lens 5a is located in front of the light emitting element 2, and is configured to emit the infrared rays emitted from the light emitting element 2 while condensing them. The lens 5 b is positioned in front of the light receiving element 3, and is configured to collect the infrared light transmitted to the infrared data communication module A and enter the light receiving element 3. A central portion 5c is formed between the lenses 5a and 5b. The central portion 5c covers the drive IC 4. In the present embodiment, the height of the lenses 5a and 5b is about 1 mm, and the thickness of the central portion 5c is 0.46 mm.

  The shield cover 6 is used for electromagnetic shielding and light shielding with respect to the driving IC 4, and is provided so as to cover the substrate 1 and the resin package 5. The shield cover 6 is formed, for example, by bending an iron metal plate, and includes a top plate 61, two spring portions 62, and a terminal 63. The top plate 61 is sized to be disposed between the lenses 5a and 5b, and covers the central portion 5c. The two spring portions 62 extend from the top plate 61 toward both ends of the substrate 1. As clearly shown in FIG. 2, the spring portion 62 is composed of a portion inclined with respect to the direction in which the substrate 1 spreads and a portion parallel to the substrate 1 positioned ahead. When the top plate 61 is further moved closer to the central portion 5c from the state where the spring portion 62 is in contact with the central portion 5c, an elastic force is generated in the spring portion 62 in a direction in which the top plate 61 is separated from the central portion 5c. Four embosses 64 are formed on the shield cover 6 so as to face the side surfaces of the resin package 5. The emboss 64 exhibits a function of fixing the shield cover 6 to the resin package 5 by sandwiching the resin package 5 and a function of positioning the shield cover 6 with respect to the resin package 5. The terminal 63 is a small piece portion extending in the short direction of the substrate 1, and is for releasing a minute current generated in the shield cover 6 by the electromagnetic shield to, for example, the ground line of the circuit board.

  As shown in FIG. 2, the shield cover 6 is bonded to the resin package 5 with an adhesive 7. The adhesive 7 is filled in a space surrounded by the top plate 61, the two spring portions 62, and the central portion 5c.

  Next, the operation of the infrared data communication module A will be described.

  According to this embodiment, when attaching the shield cover 6 in the manufacturing process of the infrared data communication module A, the spring part 62 functions as a buffer part. For this reason, it is possible to avoid that the top plate 61 and the center part 5c collide illegally. As a result, even if the thickness of the central portion 5c is about 0.46 mm, it is possible to prevent the drive IC 4 from being damaged or a wire (not shown) connected to the drive IC 4 from being broken. it can. Further, if the thickness of the resin package 5 including the central portion 5c can be reduced, the thermal stress generated in the resin package 5 immediately after the resin package 5 is formed can be reduced. Since the thermal stress of the resin package 5 acts in a direction in which the substrate 1 is warped, if this thermal stress is small, there is no possibility of excessive warping even if the substrate 1 is thinned. As described above, according to the present embodiment, the resin package 5 and the substrate 1 can be finished thin, and the infrared data communication module A can be made thinner and appropriately prevented from being damaged.

  The adhesive 7 that joins the top plate 61 and the central portion 5c plays a role of reducing the stress generated when an external force that bends the infrared data communication module A is applied. For this reason, it is possible to prevent the infrared data communication module A from being damaged by a force applied when the infrared data communication module A is mounted on a circuit board.

  The optical communication module according to the present invention is not limited to the above-described embodiment. The specific configuration of each part of the optical communication module according to the present invention can be modified in various ways.

  The light emitting element and the light receiving element are not limited to those capable of emitting or receiving infrared rays, and those capable of emitting or receiving visible light may be used. That is, the optical communication module is not limited to the infrared data communication module, and may be a communication system using visible light.

It is a top view which shows an example of the optical communication module which concerns on this invention. It is sectional drawing which follows the II-II line | wire of FIG. It is a front view which shows an example of the optical communication module which concerns on this invention. It is a rear view which shows an example of the optical communication module which concerns on this invention. It is sectional drawing which shows an example of the conventional optical communication module.

Explanation of symbols

A Infrared data communication module (optical communication module)
1 Substrate 2 Light emitting element 3 Light receiving element 4 Driving IC
5 Resin package 5a, 5b Lens 5c Center part 6 Shield cover 7 Adhesive 11 Terminal 61 Top plate 62 Spring part 63 Terminal

Claims (2)

A substrate,
A light emitting element and a light receiving element mounted on the substrate apart from each other;
A resin package having two lenses formed in front of each of the light emitting element and the light receiving element, and covering the light emitting element and the light receiving element;
A shield cover for electromagnetic shielding and light shielding of the light emitting element and the light receiving element;
An optical communication module comprising:
The shield cover includes a top plate that covers a central portion located between the two lenses of the resin package, and extends from the top plate, and when the top plate is brought close to the resin package. One or more spring parts which produce an elastic force are provided, The optical communication module characterized by the above-mentioned. The shield cover has two spring portions that are separated from each other,
The adhesive which joins the said shield cover and the said resin package is provided in the space enclosed by the said 2nd spring part, the said top plate, and the said center part of the said resin package. Optical communication module.

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