JP2007081134A - Optical communication module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical communication module in which consideration is given to eye safety and a design for manufacturing. <P>SOLUTION: The optical communication module 1 comprises a lead frame 2, a laser diode 3 provided to the lead frame 2, and a transparent resin 4 as an adjusting means for expanding the optical output distribution of the laser diode 3 and for adjusting the output of the laser diode 3. The transparent resin 4 comprises a transparent resin 6 for sealing the laser diode 3, and a glass feeler 7 which is added to the transparent resin 6 and distributed substantially evenly over the entire transparent resin 6. The glass feeler 7 is capable of passing through and dispersing light. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical communication module including a laser diode in its configuration.

  An optical communication module is known as one of components for performing optical communication. The optical communication module is called FOT (Fiber Optic Transceiver) in Patent Document 1 below, and includes a lead frame, a light source provided in the lead frame, a light source and a transparent resin portion that seals the periphery of the light source ( A portion made of a transparent resin). The transparent resin portion is provided in order to prevent the light emitting source from being affected by mechanical impacts and atmospheric changes.

As a technique that can be applied to the transparent resin portion, for example, Patent Document 2 below can be cited. Patent Document 2 below discloses the following technique. That is, Patent Document 2 below discloses a technique for adding a glass filler in order to impart weather resistance to a transparent resin. Patent Document 2 below discloses a technique for regulating the Abbe number and the like, and consideration is given so that the transmittance of light from a light source does not decrease even when a glass filler is added. The following Patent Document 2 is a useful technique for making a resin composition having weather resistance and excellent transmittance.
JP 2001-168380 A JP 2001-261367 A

  In the conventional FOT, the light source is an LED. In contrast, the inventor of the present application intends to manufacture an optical communication module by providing a laser diode on a lead frame. Laser diodes are known to have a much narrower light output distribution than LEDs. Therefore, it is necessary to adopt an active alignment method for positioning. If the active alignment method is employed, the manufacturing tact will be greatly affected. In addition to the active alignment method, a method of managing the assembly tolerance of the housing for the laser diode more strictly than the normal tight tolerance is conceivable.

  Laser diodes are also known for their large output. Since the optical communication module considered by the present inventor is provided with a laser diode, it is necessary to sufficiently consider the influence on the human body due to the increase in the output amount. In other words, eye safety must be fully considered.

  This invention is made | formed in view of the situation mentioned above, and makes it a subject to provide the optical communication module in which consideration was given to manufacturability and eye safety.

  The optical communication module of the present invention according to claim 1, which has been made to solve the above problems, includes a lead frame, a laser diode provided in the lead frame, and an adjustment for performing optical output distribution expansion and output adjustment of the laser diode. And the adjustment means includes a transparent resin that seals the laser diode and a glass filler that is present in all or part of the transparent resin, or a transparent that seals the laser diode. It is characterized by including a resin and a transparent glass filler adding member that is integrated with the transparent resin by adding a glass filler, and the glass filler has a light transmission and diffusion function.

  According to the present invention having such characteristics, the light from the laser diode is repeatedly refracted by the glass filler contained in the transparent resin or the glass filler contained in the glass filler-added member, and the majority is the transparent resin or glass filler. Pass through the additive member. For example, some light is refracted in the direction opposite to the traveling direction and does not reach the light emitting surface of the optical communication module. As a result, the light output amount of the optical communication module is reduced and the light output distribution is expanded.

  These two actions such that the optical output amount of the optical communication module is reduced and the optical output distribution is expanded are in inverse proportion to each other, and the usage environment of the optical communication module and the housing to which the optical communication module is attached In consideration of performance, the amount of glass filler added is optimized in the present invention. As the amount of glass filler added increases, the light output distribution expands and the light output amount attenuates. According to the present invention, since the light output amount of the optical communication module is reduced, consideration is given to the influence on the human body.

  Normally, the emission pattern of a laser diode (VCSEL) having a wavelength of 850 nm has a dent at the center, and a donut-shaped maximum light emitting portion around this. According to the present invention, a repetitive refraction by the glass filler results in a pure chevron (substantially triangular) output pattern, rather than a chevron-shaped output pattern whose top is a donut shape. In addition, the emission pattern is gently reduced. According to the present invention, alignment with a communication medium such as an optical fiber can be easily performed (active alignment is not necessary).

  An optical communication module according to a second aspect of the present invention is the optical communication module according to the first aspect, wherein the glass filler is formed in a spherical shape.

  According to the present invention having such characteristics, the light from the laser diode is repeatedly refracted by the presence of the spherical glass filler. When the shape of the glass filler is spherical, repetitive refraction and transmission are stable compared to other shapes.

  According to the first aspect of the present invention, there is an effect that it is possible to consider the manufacturability and the eye safety.

  According to the second aspect of the present invention, it is possible to stabilize repetitive refraction and transmission. Thereby, there is an effect that it is possible to further consider the manufacturability and eye safety.

  Hereinafter, description will be given with reference to the drawings. 1A and 1B are diagrams showing an embodiment of an optical communication module of the present invention. FIG. 1A is a configuration diagram of the optical communication module, and FIG. 1B is a schematic view of a transparent resin portion as an adjusting means.

  In FIG. 1, reference numeral 1 indicates an optical communication module of the present invention. The optical communication module 1 is one of components for optical communication, and performs a lead frame 2, a laser diode 3 provided in the lead frame 2, and a light output distribution expansion and output adjustment of the laser diode 3. A transparent resin portion 4 as an adjusting means is provided.

  The lead frame 2 has conductivity, and a laser diode 3 is mounted on the lead frame 2. The lower portion of the lead frame 2 is electrically connected to a substrate (not shown). In this embodiment, although not particularly limited, an 850 nm band-emitting laser (VCSEL: Vertical Cavity Surface Emitting Laser) is used as the laser diode 3. The laser diode 3 is mounted on the light emitting surface 5 side of the optical communication module 1 in the lead frame 2.

  The transparent resin portion 4 has a function of protecting the laser diode 3 and a function as an adjusting means as described above. The transparent resin portion 4 includes a transparent resin 6 that seals the laser diode 3 and a glass filler 7 that is added to the transparent resin 6 and distributed substantially uniformly throughout the transparent resin 6. The transparent resin portion 4 is formed by, for example, transfer molding (assumed to be an example).

  The transparent resin portion 4 of this embodiment has a thickness direction dimension of 2.78 mm, a thickness direction dimension between the lead frame 2 and the light emitting surface 5 of 1.50 mm, and a height direction dimension of 5.90 mm. (Assumed to be an example). Note that the reference symbol FFP in FIG. 1A indicates a light output distribution (Far Field Pattern). The light from the laser diode 3 is like FFP by the transparent resin portion 4.

  The transparent resin 6 is a transparent resin material that transmits light. In this embodiment, a transparent epoxy resin is employed. In addition to the transparent epoxy resin, a known thermoplastic resin such as an acrylic resin or a known thermosetting resin can be used.

  The glass filler 7 has a light transmission and diffusion function. A thick arrow in FIG. 1B indicates a light transmission state, and a thin arrow indicates a diffusion state (refractive state). The average particle diameter of the glass filler 7 is set so that the glass filler 7 is evenly dispersed in the transparent resin 6 (the average particle diameter and the like will be described later). The glass filler 7 is not particularly limited in shape, but is preferably formed in a spherical shape.

  Next, based on the above configuration, the difference between the optical communication module 1 of the present invention and the comparative optical communication module 11 without glass filler addition will be described with reference to FIGS.

  2A is a configuration diagram of the optical communication module 1, FIG. 2B is a schematic diagram of the transparent resin portion 4, FIG. 2C is a table of light emission angles, FIG. 2D is a diagram showing a light emission pattern, and FIG. Is a graph of an optical waveform. 3A is a configuration diagram of the comparative optical communication module 11 without glass filler addition, FIG. 3B is a table of light emission angles, FIG. 3C is a diagram showing a light emission pattern, and FIG. 3D is an optical waveform. It is a graph of.

  The configuration of the optical communication module 1 is as described above. First, the configuration of the comparative optical communication module 11 without glass filler addition in FIG. 3 will be described.

  In FIG. 3A, the comparison optical communication module 11 includes a lead frame 2, a laser diode 3 provided on the lead frame 2, and a transparent resin 6 that protects the laser diode 3. The optical communication module 11 for comparison is different from the optical communication module 1 described above in that the glass filler 7 (see FIGS. 1 and 2) is not added and the transparent resin portion 4 (see FIGS. 1 and 2) is not formed. ing. The transparent resin 6 of the comparative optical communication module 11 is formed to have the same size as the transparent resin portion 4 (see FIGS. 1 and 2). Since the comparison optical communication module 11 does not have a function as the adjusting means, the FFP due to the light from the laser diode 3 does not spread.

  Note that the same applies to the case where the comparative optical communication module 11 is constituted by the lead frame 2 and the laser diode 3 (the laser diode 3 is in an open state).

  Here, the half value of the optical waveform corresponding to 50% of Optical Power Down rate is FWHM, the value corresponding to 65% is 1 / e, the value corresponding to 85% is 1 / e2, and the value corresponding to 95%. Assuming 5%, the comparative optical communication module 11 has a light emission angle of 12.17 degrees at the half value of the optical waveform in FIG. 3D, a light emission angle of 14.67 degrees at 1 / e, The measurement result shows that the light emission angle at 1 / e2 is 14.67 degrees, and the light emission angle at 5% is 36.91 degrees (see FIG. 3B). The optical waveform has a donut shape with a low output at the center and a maximum value at the periphery (see FIG. 3C). Since the optical communication module 11 for comparison has a donut shape at the top of the optical waveform, for example, it is easy to cause an axial deviation at the time of optical fitting with an optical fiber, and this axial deviation greatly affects the characteristics. It is like that.

  Next, the optical communication module 1 of the present invention will be described.

  2, the optical communication module 1 has a light emission angle of 26.49 degrees at the half value of the optical waveform of FIG. 2E, a light emission angle of 33.48 degrees at 1 / e, and 1 / e2. The measurement result shows that the light emission angle at the time is 52.26 degrees and the light emission angle at the time of 5% is 64.14 degrees (see FIG. 2C). The optical waveform has a pure mountain shape (substantially triangular shape) having the highest value at the center (see FIG. 2D). In addition, the optical waveform is gradually lowered. Therefore, it is larger than a normal fitting error allowable value. The optical communication module 1 is superior in housing design. The optical communication module 1 is easily aligned with a communication medium such as an optical fiber.

  In the optical communication module 1, the light from the laser diode 3 is repeatedly refracted by the presence of the glass filler 7, and most of the light passes through the transparent resin 6. Further, a part of the light is refracted in the direction opposite to the traveling direction, for example, and does not reach the light emitting surface 5 of the optical communication module 1. In the present invention, the light output amount of the optical communication module 1 is reduced, and the light output distribution is expanded.

  These two actions such that the light output amount of the optical communication module 1 decreases and the light output distribution expands are inversely related to each other, and the usage environment of the optical communication module 1 and the mounting of the optical communication module 1 In consideration of the target housing performance, the present invention optimizes the addition amount of the glass filler 7. As the amount of glass filler 7 added is increased, the light output distribution is expanded and the light output amount is attenuated.

  Then, the content rate etc. of the glass filler 7 are demonstrated. Fig.4 (a) is a graph regarding a glass filler content rate, FIG.4 (b) is a table | surface regarding a glass filler content rate. 5A is a graph relating to the glass filler particle size, and FIG. 5B is a table relating to the glass filler particle size.

  In FIG. 4, the content rate of the glass filler 7 is divided into 6 stages from 0% to 75%, 50% (half-value time), 65% (1 / e time), 85% (1 / e2 time), 95% ( As a result of comparing the light spread angle at 5%, a result that there is a proportional relationship between the content of the glass filler 7 and the spread angle was obtained. Therefore, the target spread angle can be output by adjusting the content of the glass filler 7.

  In FIG. 5, the average particle size of the glass filler 7 is divided into 5 stages from 5 μm to 100 μm in 50 steps (at half-value), 65% (at 1 / e), 85% (at 1 / e2), and 95% (5 As a result of comparing the light spread angle at the time of%), it was found that the average particle diameter and the spread angle of the glass filler 7 have a semi-proportional relationship. Accordingly, the target spread angle can be output by adjusting the average particle size of the glass filler 7.

  4 and 5, one result is that the light spreading angle of 95% (at 5%) is 36.91 degrees in the case of the comparative optical communication module 11 not including the glass filler 7 (see FIG. 3). When the glass filler 7 having an average particle size of 30 μm was blended with the transparent resin 6 at a volume ratio of 50%, it was 64.14 degrees.

  Subsequently, another example will be described. In the above description, the glass filler 7 is distributed substantially uniformly throughout the transparent resin 6, but the glass filler 7 may be distributed only in necessary places. In addition, a configuration as shown in FIG.

  In FIG. 6A, the optical communication module 21 includes a lead frame 2, a laser diode 3 provided on the lead frame 2, and an adjusting unit 22 for expanding the light output distribution and adjusting the output of the laser diode 3. It is configured. The adjusting means 22 includes a transparent resin 6 that seals the laser diode 3 and a transparent glass filler addition member 23 that is added to the glass resin 7 and integrated with the transparent resin 6. The glass filler addition member 23 is plate-shaped and is disposed and formed so as to be integrated with the front surface of the transparent resin 6 (if the glass filler addition member 23 is integrated, the number of parts at the time of assembly is not increased. If several glass filler additive members 23 in which the content and average particle size of the glass filler 7 are adjusted are prepared, variations are improved).

  6B, the optical communication module 31 differs from the optical communication module 21 in FIG. 6A only in the arrangement and shape of the glass filler added member. The adjusting means 32 includes a transparent resin 6 that seals the laser diode 3 and a transparent glass filler addition member 33 that is added to the transparent resin 6 by adding the glass filler 7. The glass filler additive member 33 has a cylindrical shape, and is disposed and formed so as to be integrated with the transparent resin 6 in front of the laser diode 3 (if the glass filler additive member 33 is integrated, the number of parts at the time of assembly is increased). If several glass filler additive members 33 with adjusted content and average particle size of the glass filler 7 are prepared, variations are improved).

  As described above with reference to FIGS. 1 to 6, according to the present invention, there is an effect that it is possible to provide an optical communication module in which consideration is given to manufacturability and eye safety.

  Other effects of the present invention include the following effects. That is, it is possible to relax the design restrictions on the housing for the laser diode, which normally required strict assembly crossing. In addition, the output waveform can be controlled without using a load component such as a lens, which can greatly reduce the cost.

  The addition of the glass filler 7 has a great effect on improving heat resistance and weather resistance, and also exerts a great effect on improving reliability, so that a synergistic effect is obtained.

  In addition, it goes without saying that the present invention can be variously modified without departing from the spirit of the present invention.

It is a figure which shows one Embodiment of the optical communication module of this invention, (a) is a block diagram of an optical communication module, (b) is a schematic diagram of the transparent resin part as an adjustment means. (A) is a block diagram of an optical communication module, (b) is a schematic diagram of a transparent resin portion, (c) is a table of light emission angles, (d) is a diagram showing a light emission pattern, and (e) is an optical waveform. It is a graph. (A) is a block diagram of an optical communication module for comparison without glass filler addition, (b) is a table of light emission angles, (c) is a diagram showing a light emission pattern, and (d) is a graph of an optical waveform. (A) is a graph regarding a glass filler content rate, (b) is a table | surface regarding a glass filler content rate. (A) is a graph regarding a glass filler particle size, (b) is a table | surface regarding a glass filler particle size. (A) And (b) is a block diagram which shows other one Embodiment of the optical communication module of this invention, respectively.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical communication module 2 Lead frame 3 Laser diode 4 Transparent resin part (adjustment means)
DESCRIPTION OF SYMBOLS 5 Light emission surface 6 Transparent resin 7 Glass filler 21 Optical communication module 22 Adjustment means 23 Glass filler addition member 31 Optical communication module 32 Adjustment means 33 Glass filler addition member

Claims (2)

A lead frame, a laser diode provided in the lead frame, and an adjusting means for performing optical power distribution expansion and output adjustment of the laser diode;
The adjustment means includes a transparent resin that seals the laser diode and a glass filler that is present in all or part of the transparent resin, or a transparent resin that seals the laser diode, and a glass filler. And comprising a transparent glass filler additive member that is integrated with the transparent resin,
An optical communication module, wherein the glass filler has a light transmission and diffusion function. The optical communication module according to claim 1,
An optical communication module, wherein the glass filler is formed in a spherical shape.

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