JP5043553B2 - Optical semiconductor module - Google Patents

Description

  The present invention relates to an optical semiconductor module used for signal exchange between two circuits that require electrical insulation, for example, by allowing light from an input-side light-emitting element to be received by an output-side light-receiving element.

  FIG. 9 shows an example of a conventional optical semiconductor module. The optical semiconductor module X shown in the figure includes an input side lead 91A and an output side lead 91B which are spaced apart from each other, and a light emitting element 92 and a light receiving element 93 mounted thereon. The light emitting element 92 and the light receiving element 93 are covered with a transparent resin 94. The transparent resin 94 is covered with a sealing resin 95 made of an opaque resin. When a potential is applied to the input lead 91A, the light emitting element 92 emits light. Most of the light is reflected by the interface between the transparent resin 94 and the sealing resin 95 and then received by the light receiving element 93. When an electromotive force is generated by light reception of the light receiving element 93, a signal is output from the output side lead 91B. With such a configuration, signal exchange between two circuits that need to be electrically insulated from each other can be realized.

  However, the conversion efficiency, which is the ratio between the power input to the light emitting element 92 and the power output from the light receiving element 93, is greatly influenced by the shape of the transparent resin 94. If the shape of the transparent resin 94 is inappropriate such as an extremely flat shape, the conversion efficiency is unduly reduced. Further, when the transparent resins 94 are not uniform in the plurality of optical semiconductor modules X, there is a problem that the conversion efficiency of the individual optical semiconductor modules X varies greatly.

Japanese Patent Laid-Open No. 11-238910

  The present invention has been conceived under the above circumstances, and provides an optical semiconductor module capable of increasing conversion efficiency and suppressing variations in conversion efficiency, and a method for manufacturing the same. Let it be an issue.

  An optical semiconductor module provided by the first aspect of the present invention includes an input-side lead and an output-side lead that are spaced apart from each other in the same plane, a light-emitting element mounted on the input-side lead, and the output-side lead. An optical semiconductor module comprising: a light receiving element mounted on the light emitting element; and a transparent resin covering the light emitting element and the light receiving element, wherein the input-side lead is opposite to the light receiving element with respect to the light emitting element. A discontinuous portion including a surface on which the light emitting element is mounted and a surface lower than this surface is formed, and the output side lead is connected to the light receiving element. A discontinuous portion including a surface on the opposite side of the light emitting element and including a surface on which the light receiving element is mounted and a surface lower than the surface. The structural discontinuities of de and the output side leads, is characterized in that it forms part of the contour of the transparent resin.

  According to such a structure, it is possible to make the said dome part the shape which protruded notably. Thereby, the conversion efficiency of the said optical semiconductor module can be improved. Moreover, it is possible to make the shape of the said dome part uniform. This is suitable for suppressing variations in the conversion efficiency of the optical semiconductor module.

  In a preferred embodiment of the present invention, the structural discontinuity portion of the input-side lead surrounds the entire circumference of the light-emitting element, and the structural discontinuity portion of the output-side lead is the whole of the light-receiving element. Surrounding the circumference. Such a configuration is suitable for making the dome portion bulge significantly.

  In a preferred embodiment of the present invention, the structural discontinuities of the input side lead and the output side lead are grooves. According to such a configuration, the structural discontinuity referred to in the present invention can be formed easily and appropriately.

  An optical semiconductor module manufacturing method provided by the second aspect of the present invention includes an input-side lead and an output-side lead spaced apart from each other in the same plane, a light-emitting element mounted on the input-side lead, An optical semiconductor module manufacturing method comprising: a light receiving element mounted on an output-side lead; and a light-emitting element and a transparent resin covering the light-receiving element. On the other hand, a structural discontinuity portion is formed that includes a portion located on the opposite side of the light receiving element mounting planned position and includes a surface on which the light emitting element is mounted and a lower surface than the surface. The output-side lead includes a portion located on the side opposite to the light emitting element mounting planned position with respect to the light receiving element mounting planned position, and a surface on which the light receiving element is mounted and this surface A discontinuous structure including a lower surface is formed, the step of mounting the light emitting element and the light receiving element on the input side lead and the output side lead, and potting a liquid transparent resin By covering the light emitting element and forming a dome part having the structural discontinuity part as a part of the contour on the input lead, and by potting a liquid transparent resin, the light receiving element is covered, And a step of forming a dome portion having the discontinuous portion as a part of the contour on the output side lead, and a step of forming a bridging portion connecting the two dome portions by potting a liquid transparent resin. It is characterized by having.

  According to such a structure, it is possible to make the said dome part the shape which protruded notably. In addition, if the amount of the liquid transparent resin dripped onto the region surrounded by the structural discontinuity is constant, the shape of the dome can be made uniform. Therefore, the conversion efficiency of the optical semiconductor module can be improved and variation can be prevented.

  In a preferred embodiment of the present invention, the structural discontinuity portion of the input-side lead surrounds the entire circumference of the light-emitting element, and the structural discontinuity portion of the output-side lead is the whole of the light-receiving element. Surrounding the circumference. Such a configuration is suitable for making the dome portion bulge significantly.

  In a preferred embodiment of the present invention, the structural discontinuities of the input side lead and the output side lead are grooves. According to such a configuration, the structural discontinuity referred to in the present invention can be formed easily and appropriately.

  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 and 2 show a first embodiment of an optical semiconductor module according to the present invention. The optical semiconductor module A1 of this embodiment includes an input side lead 1A, an output side lead 1B, a light emitting element 2, a light receiving element 3, a transparent resin 4, and a sealing resin 5. The optical semiconductor module A1 is used for signal exchange between two circuits that are required to be electrically insulated, for example. In FIG. 2, the sealing resin 5 is indicated by an imaginary line for convenience of understanding.

  The input-side lead 1A is made of, for example, Cu, Ni, or an alloy thereof, and is for mounting the light emitting element 2. A groove 11A is formed in the input lead 1A. The groove 11 </ b> A is annular and surrounds the entire circumference of the light emitting element 2.

  The output-side lead 1B is made of, for example, Cu, Ni, or an alloy thereof, and is for mounting the light receiving element 3. A groove 11B is formed in the output lead 1B. The groove 11 </ b> B is annular and surrounds the entire circumference of the light receiving element 3.

  The grooves 11A and 11B are examples of the structural discontinuity referred to in the present invention. The bottom surfaces of the grooves 11A and 11B are lower surfaces than the surface on which the light emitting element 2 or the light receiving element 3 is mounted. As described above, the structure discontinuity referred to in the present invention includes the grooves 11A and 11B, and the surface lower than the surface on which these are mounted at a position separated from the light emitting element 2 or the light receiving element 3. Refers to the structure that is.

  The light emitting element 2 is, for example, an LED chip, and is configured to emit light of a certain wavelength. The light emitting element 2 is connected to the lead 1 </ b> C via the wire 6.

  The light receiving element 3 is, for example, a PIN photodiode, and generates an electromotive force according to the amount of received light. The light receiving element 3 is connected to the lead 1 </ b> D through the wire 6.

  The transparent resin 4 covers the light emitting element 2 and the light receiving element 3, and is made of, for example, a transparent photocurable resin. The transparent resin 4 includes dome portions 41A and 41B and a bridging portion 42. The dome portions 41A and 41B have a shape that bulges away from the input side lead 1A and the output side lead 1B. The dome part 41 </ b> A covers the light emitting element 2, and the dome part 41 </ b> B covers the light receiving element 3. The dome portion 41A is formed in a region surrounded by the groove 11A, and an outline is formed by the groove 11A. The dome portion 41B is formed in a region surrounded by the groove 11B, and an outline is formed by the groove 11B. The bridging portion 42 is formed so as to connect the dome portions 41A and 41B. The dome portions 41A and 41B and the bridging portion 42 are formed of the same material. For this reason, light refraction and total reflection hardly occur at the mutual interfaces.

  The sealing resin 5 covers the input side lead 1A, the output side lead 1B, and a part of each of the leads 1C and 1D and the transparent resin 4, and is made of, for example, an opaque epoxy resin. Of the input side lead 1A, the output side lead 1B, and the leads 1C and 1D, the portion exposed from the sealing resin 5 is used as a terminal for mounting the optical semiconductor module A1 on a circuit board or the like.

  Next, an example of a method for manufacturing the optical semiconductor module A1 will be described below with reference to FIGS.

  First, as shown in FIG. 3, an input side lead 1A, an output side lead 1B, and leads 1C and 1D are prepared. A lead frame in which these leads are connected to each other by a frame may be used. A groove 11A is formed in the input lead 1A, and a groove 11B is formed in the output lead 1B. The grooves 11A and 11B are formed by etching or punching, for example.

  Next, as shown in FIG. 4, the light emitting element 2 and the light receiving element 3 are die-bonded to the input side lead 1A and the output side lead 1B. Further, the light emitting element 2 and the light receiving element 3 are connected to the leads 1C and 1D using the wire 6.

  Next, as shown in FIG. 5, the liquid photo-curing resin is potted from the nozzle Nz into the region surrounded by the groove 11A. The liquid photocurable resin spreads the region surrounded by the groove 11A and reaches the inner edge of the groove 11A. The inner edge of the groove 11A is a wall surface that stands up toward the bottom surface of the groove 11A. Therefore, the liquid photocurable resin is prevented from exceeding the inner edge of the groove 11A due to the surface tension of the liquid photocurable resin. As a result, the liquid photocurable resin becomes a dome shape covering the light emitting element 2. Similarly, the liquid photo-curing resin is potted from the nozzle Nz to the region surrounded by the groove 11B. As a result, the liquid photocurable resin has a dome shape covering the light receiving element 3. A light having a predetermined wavelength is irradiated to the liquid photocurable resin in the form of a dome. Thereby, dome parts 41A and 41B are obtained.

  Next, as shown in FIG. 6, the liquid photo-curing resin is potted from the nozzle Nz so as to cover, for example, the dome portion 41A. Subsequently, the nozzle Nz is moved while potting toward the dome portion 41B. As a result, the liquid photo-curable resin is connected to the dome portions 41A and 41B. The liquid photocurable resin is irradiated with light having a predetermined wavelength. Thereby, the bridging part 42 is obtained and the transparent resin 4 is formed. Thereafter, the sealing resin 5 is formed by molding, for example. Through the above steps, the optical semiconductor module A1 shown in FIGS. 1 and 2 is obtained.

  Next, the operation of the optical semiconductor module A1 and the manufacturing method thereof will be described.

  According to the present embodiment, the dome portions 41A and 41B can have a shape that bulges significantly upward. Thereby, the light from the light emitting element 2 can be appropriately reflected toward the dome portion 41B by the interface between the dome portion 41A and the sealing resin 5. In addition, the light traveling to the dome portion 41B can be appropriately reflected toward the light receiving element 3 by the interface between the dome portion 41B and the sealing resin 5. Therefore, the light from the light emitting element 2 can be efficiently incident on the light receiving element 3, and the conversion efficiency of the optical semiconductor module A1 can be increased.

  The outlines of the dome portions 41A and 41B are defined by the grooves 11A and 11B. In the potting for forming the dome portions 41A and 41B, the shape of the dome portions 41A and 41B can be made constant if the amount of the liquid photocurable resin to be dropped is made constant. Thereby, the shape of the transparent resin 4 is also constant. Therefore, variations in the conversion efficiency of the optical semiconductor module A1 can be suppressed.

  FIG. 7 shows a second embodiment of the optical semiconductor module according to the present invention. In this figure, the same or similar elements as those in the above embodiment are given the same reference numerals as those in the above embodiment.

  The optical semiconductor module A2 of the present embodiment is different from the above-described embodiments in the shapes of the grooves 11A and 11B. FIG. 8 shows an input side lead 1A, an output side lead 1B, and leads 1C and 1D used in the optical semiconductor module A2. In the present embodiment, the grooves 11 </ b> A and 11 </ b> B are not formed in a region sandwiched between the light emitting element 2 and the light receiving element 3. The grooves 11 </ b> A and 11 </ b> B have a shape that surrounds the light emitting element 2 and the light receiving element 3.

  Also according to such an embodiment, it is possible to make the dome portions 41A and 41B bulge upward, and it is possible to improve the conversion efficiency and prevent variation of the optical semiconductor module A2. In the present embodiment, the liquid photocurable resin dropped in the region surrounded by the groove 11A is prevented from being unduly spread by the groove 11A and the left end edge of the input side lead 1A. Similarly, the liquid photocurable resin dropped in the region surrounded by the groove 11B is prevented from being unduly spread by the groove 11B and the right end edge of the output side lead 1B.

  The optical semiconductor module and the manufacturing method thereof according to the present invention are not limited to the above-described embodiments. The specific configuration of the optical semiconductor module and the manufacturing method thereof according to the present invention can be varied in design in various ways.

  The material of the transparent resin 4 is preferably a photocurable resin, but is not limited to this, and has a viscosity that allows the light from the light emitting element 2 to pass through and can appropriately form the dome portions 41A and 41B. If it is.

1 is a cross-sectional view showing a first embodiment of an optical semiconductor module according to the present invention. It is a top view which shows the optical semiconductor module shown in FIG. It is a top view which shows the lead used for an example of the manufacturing method of the optical semiconductor module shown in FIG. The light shown in FIG. 1 is a cross-sectional view showing a state in which a light emitting element and a light receiving element are mounted in an example of a method for manufacturing a conductor module. The light shown in FIG. 1 is a cross-sectional view showing a step of forming a dome portion in an example of a method of manufacturing a conductor module. The light shown in FIG. 1 is a cross-sectional view showing a step of forming a bridging portion in an example of a method for manufacturing a conductor module. It is sectional drawing which shows 2nd Embodiment of the optical semiconductor module which concerns on this invention. It is a top view which shows the lead used for an example of the manufacturing method of the optical semiconductor module shown in FIG. It is sectional drawing which shows an example of the conventional optical semiconductor module.

Explanation of symbols

A1, A2 Optical semiconductor module 1A Input side lead 1B Output side lead 1C, 1D Lead 2 Light emitting element 3 Light receiving element 4 Transparent resin 5 Sealing resin 6 Wire 11A, 11B Groove 41A, 41B Dome part 42 Bridge part

Claims (6)

An input side lead and an output side lead spaced apart from each other in the same plane;
A light emitting element mounted on the input lead;
A light receiving element mounted on the output side lead;
A transparent resin covering the light emitting element and the light receiving element;
An optical semiconductor module comprising:
The input-side lead includes a portion located on the side opposite to the light receiving element with respect to the light emitting element, and a discontinuous structure including a surface on which the light emitting element is mounted and a surface lower than this surface Part is formed,
The output-side lead includes a portion located on the opposite side of the light-emitting element with respect to the light-receiving element, and includes a surface on which the light-receiving element is mounted and a surface lower than this surface. Part is formed,
The optical semiconductor module, wherein the structural discontinuities of the input side lead and the output side lead form a part of the outline of the transparent resin. The structural discontinuity of the input side lead surrounds the entire circumference of the light emitting element,
The optical semiconductor module according to claim 1, wherein the discontinuous portion of the structure of the output side lead surrounds the entire circumference of the light receiving element.   The optical semiconductor module according to claim 1, wherein the structural discontinuity portions of the input side lead and the output side lead are grooves. An input side lead and an output side lead spaced apart from each other in the same plane;
A light emitting element mounted on the input lead;
A light receiving element mounted on the output side lead;
A transparent resin covering the light emitting element and the light receiving element;
An optical semiconductor module manufacturing method comprising:
The input-side lead includes a portion located on the opposite side of the light receiving element mounting planned position with respect to the light emitting element mounting planned position, and is a lower surface than the surface on which the light emitting element is mounted. Structural discontinuities including the surface are formed,
The output side lead includes a portion located on the opposite side of the light receiving element mounting position with respect to the light receiving element mounting planned position, and is a lower surface than the surface on which the light receiving element is mounted. Structural discontinuities including the surface are formed,
Mounting the light emitting element and the light receiving element on the input side lead and the output side lead;
Forming a dome portion on the input-side lead that covers the light-emitting element by potting a liquid transparent resin and has the structural discontinuity as a part of the contour;
Forming a dome portion on the output-side lead that covers the light receiving element by potting a liquid transparent resin and has the structural discontinuity as a part of the contour;
And a step of forming a bridging portion that connects the two dome portions by potting a liquid transparent resin. The structural discontinuity of the input side lead surrounds the entire circumference of the light emitting element,
The method of manufacturing an optical semiconductor module according to claim 4, wherein the discontinuous portion of the structure of the output side lead surrounds the entire circumference of the light receiving element.   6. The optical semiconductor module according to claim 4, wherein the structural discontinuity portion of the input side lead and the output side lead is a groove.

Images