JP4197569B2 - Infrared data communication module - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an infrared data communication module used for electronic devices such as personal computers, printers, PDAs, facsimiles, pagers, and mobile phones.
[0002]
[Prior art]
In recent years, there has been a strong demand for miniaturization of infrared data communication modules in portable devices such as notebook personal computers, PDAs, and mobile phones equipped with optical communication functions. LED molded light-emitting element, photodiode light-receiving element, amplifier, drive circuit and other IC chip circuit parts are directly die-bonded and wire-bonded to the lead frame. Therefore, an infrared data communication module in which a transmitter and a receiver are packaged has been developed. A general structure of a conventional general infrared data communication module will be described.
[0003]
In a board type infrared data communication module, a light emitting element and a light receiving element are mounted on the upper surface side of a circuit board, the IC chip is mounted on a lower surface side, and an infrared ray covering the entire module with a shield case to provide a shielding effect The technology of the data communication module is disclosed in Japanese Patent Laid-Open No. 10-233471. This will be described below with reference to the drawings (FIGS. 7 and 8).
[0004]
7 and 8, reference numeral 1 denotes a circuit board made of glass epoxy resin or the like and having a substantially rectangular insulating surface. Conductive patterns (not shown) formed on the upper and lower surfaces of the circuit board 1 Electrical connection is made through the through-hole electrode 2a of the through-hole 2 formed on the plane. The through-hole electrodes of the plurality of through-holes 6 formed on one side surface of the circuit board 1 serve as external connection electrodes 6a connected to a wiring pattern of a mother board (not shown) such as a printed board. A part of the external connection electrode 6a, which is a through-hole electrode of the through hole 6, extends to the lower surface of the circuit board 1 to form an external connection electrode 6b to enable side mounting. The circuit board 1 uses a glass epoxy substrate, but an alumina ceramic substrate, a plastic film substrate such as polyester or polyimide, or the like may be used.
[0005]
Further, 3 is a light emitting element made of a high-speed infrared LED, and 4 is a light receiving element made of a photodiode. Both are mounted on the upper surface side of the circuit board 1 and connected to the conductive pattern by die bonding and wire bonding. Reference numeral 5 denotes an IC chip having a circuit portion in which a high-speed amplifier, a drive circuit and the like are incorporated, which are die-bonded and wire-bonded to the conductive pattern on the lower surface side of the circuit board 1 and connected through the through-hole electrode 2a of the through-hole 2 Has been.
[0006]
In the figure, 7 is an epoxy-based translucent resin containing a visible light cut agent that seals the light emitting element 3 and the light receiving element 4 with resin. The translucent resin 7 forms hemispherical lens portions 7a and 7b on the upper surfaces of the light-emitting element 3 and the light-receiving element 4, thereby providing both infrared light irradiation and condensing functions and at the same time protecting both elements. . The sealing of the IC chip 5 mounted on the lower surface of the circuit board 1 is not limited to the translucent resin 7 and may be sealed with another thermosetting resin.
[0007]
As shown in FIGS. 7 and 8, the infrared data communication module described above has through holes at positions corresponding to the hemispherical lens portions 7a and 7b formed on the top surfaces of the light emitting element 3 and the light receiving element 4, and is provided on the motherboard. In the case of side mounting, the module body is covered with a shield case 8 made of a member such as stainless steel, aluminum, or copper having an opening at a position corresponding to the external connection electrode surface 6a formed on the side surface of the circuit board 1. Therefore, since the circuit portion and the like are enclosed, it is possible to take countermeasures against electromagnetic shielding, which is extremely effective in preventing the influence of external noise and the like. Accordingly, the surfaces other than those mounted on the hemispherical lens portions 7a and 7b and the mother board are covered with the shield case 8.
[0008]
However, the above-described substrate type infrared data communication module has a structure in which the entire module is covered with a shield case in order to provide a shielding effect, so that the size of the product is large and the size is limited. In addition, the metal case has a problem such as an increase in weight.
[0009]
Therefore, the present applicant arranges a light-emitting element composed of a high-speed infrared LED and a light-receiving element composed of a photodiode on the front side of the circuit board, and has a magnetic shield function in which an IC chip on the back side is mounted. A particularly lightweight infrared data communication module has been developed. The outline will be described below with reference to FIGS.
[0010]
A difference from the above-described conventional technique is that a mold frame 9 is fixed to the lower surface of the circuit board 1 with an adhesive or the like so as to surround the resin-sealed IC chip 5 on the lower side of the circuit board 1. The opening 9 a of the mold frame 9 is closed with the magnetic shield plate 10 so as to cover the upper surface. The shield plate 10 is made of a plate metal made of a member such as stainless steel, aluminum, or copper, and provides a shielding effect. The shield plate 10 is connected to the GND terminal 12 of the module. Connection is performed by fixing means such as soldering when the module is mounted.
[0011]
In order to mount the infrared data communication module 20 on the mother board 11 such as a printed circuit board of various devices, the external connection electrode 6a (through-hole electrode) on the infrared data communication module 20 side is positioned in the wiring pattern of the mother board 11. After the alignment, the shield plate 10 is connected to the GND terminal 12 of the module with solder 13 by a fixing means such as soldering. The light emitting element 3 and the light receiving element 4 can be mounted on the side so that the light emitting and receiving directions are parallel to the surface of the mother board 11.
[0012]
[Problems to be solved by the invention]
The infrared data communication module described above can be reduced in size and weight by electromagnetically shielding the upper part of the IC chip with a shield plate. However, when the module is soldered to the wiring pattern of the motherboard, the external connection electrode of the module is used. Since the soldering part is invisible by the mold frame, the soldering workability is not good. Also, it becomes difficult to confirm the soldered state after mounting. Therefore, it is a problem to realize an infrared data communication module that is small and lightweight, that can be easily soldered for side mounting, and that allows easy confirmation of the soldered state after mounting.
[0013]
The present invention has been made in view of the above-described conventional problems. The object of the present invention is to provide a light-emitting element and a light-receiving element on the surface of a circuit board, and to mount an IC chip on the back side. In particular, it is an object of the present invention to provide an infrared data communication module that facilitates soldering for side mounting and allows easy confirmation of the soldered state after mounting.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, an infrared data communication module according to the present invention includes a through hole electrode of a through hole formed on a plane of the substrate, and a conductive pattern formed on the top and bottom surfaces of the substantially rectangular substrate. A circuit board having an external connection through-hole electrode connected to a wiring pattern such as a printed circuit board on at least one side surface of the board, and a light emitting element on the upper surface side of the circuit board At least the light emitting element and the light receiving element are mounted among the electronic components such as the light receiving element, the IC chip, and the capacitor, the IC chip is mounted on the lower surface side, and the upper surface of the light emitting element and the light receiving element on the upper surface side is covered with the hemispherical lens unit. outside together with resin sealing of a translucent resin, the lower surface of the IC chip sealed with resin by potting resin, is formed on the side surface of the circuit board so that In the infrared data communication module to be a side mounted on a motherboard at the connecting through-hole, and fixed to the frame substrate of the circuit board and the same outer shape with a conductive adhesive or an adhesive to the lower surface of the circuit board surrounding the IC chip, IC The opening of the frame substrate is closed with a magnetic shield plate so as to cover the chip, and the frame substrate has an external connection through-hole electrode communicating with the external connection through-hole electrode formed on the circuit substrate, By connecting the through-hole electrodes for external connection of the frame substrate, the external connection electrodes are extended to the back surface of the module.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an infrared data communication module according to the present invention will be described with reference to the drawings. 1 to 3 relate to an infrared data communication module according to an embodiment of the present invention, FIG. 1 is a cross-sectional view of the infrared data communication module, FIG. 2 is a perspective view of the frame substrate of FIG. It is a rear view of FIG. In the figure, the same members as those in the prior art are denoted by the same reference numerals.
[0016]
1 to 3, reference numeral 30 denotes an infrared data communication module according to the present invention. The configuration will be described. Reference numeral 1 denotes an insulating circuit board made of glass epoxy resin or the like. A conductive pattern (not shown) formed on the upper and lower surfaces of the circuit board 1 has a through-hole electrode 2a of a through-hole 2 formed on the plane of the circuit board 1. Electrical connection through Further, through-hole electrodes of a plurality of through-holes 6 for external connection formed on one side surface of the circuit board 1 serve as external connection electrodes 6a connected to a wiring pattern of a mother board 11 such as a printed circuit board. A part of the external connection electrode 6a, which is a through hole electrode of the through hole 6, extends to the lower surface of the circuit board 1 to form an external connection electrode, thereby enabling side mounting.
[0017]
In the figure, 3 is a light emitting element made of a high-speed infrared LED, and 4 is a light receiving element made of a photodiode. Both are mounted on the upper surface side of the circuit board 1 and connected to the conductive pattern by die bonding and wire bonding. Reference numeral 5 denotes an IC chip having a circuit portion in which a high-speed amplifier, a drive circuit and the like are incorporated, which are die-bonded and wire-bonded to the conductive pattern on the lower surface side of the circuit board 1 and connected through the through-hole electrode 2a of the through-hole 2 Has been.
[0018]
In the figure, 7 is an epoxy-based translucent resin containing a visible light cut agent that seals the light-emitting element 3 and the light-receiving element 4 with a resin as in the prior art. The translucent resin 7 forms hemispherical lens portions 7a and 7b on the upper surfaces of the light-emitting element 3 and the light-receiving element 4, thereby providing both infrared light irradiation and condensing functions and at the same time protecting both elements. . The IC chip 5 mounted on the lower surface of the circuit board 1 is sealed with a potting resin 7. The sealing resin is not limited to the translucent resin 7 and may be sealed with another thermosetting resin.
[0019]
A frame substrate 14, which will be described later, surrounds the IC chip 5 so as to surround the resin-sealed IC chip 5 below the circuit board 1, and is fixed to the lower surface of the circuit board 1 with a conductive adhesive or adhesive 16. Has been. The opening 14 a of the frame substrate 14 is closed with the magnetic shield plate 10 so as to cover the IC chip 5.
[0020]
The frame substrate 14 has external connection electrodes (through-hole electrodes) 15a formed in the through holes 15 so as to communicate with the external connection electrodes (through-hole electrodes) 6a formed on the circuit board 1 described above. . As described above, by fixing the frame substrate 14 to the lower surface of the circuit substrate 1 with the conductive adhesive or the adhesive 16, the external connection electrodes (through-hole electrodes) 6a and 15a of the circuit substrate 1 and the frame substrate 14 are connected to each other. And the external connection electrode 15a can be extended to the back surface of the module. As a result, a connection part (soldering part) with a wiring pattern formed on the mother board 11 such as a printed circuit board can be seen well, the soldering work by the solder 13 is facilitated, and the solderability is ensured. . Moreover, the soldering state after soldering can be easily confirmed.
[0021]
【The invention's effect】
As described above, according to the present invention, according to the configuration of the infrared data communication module described above, the frame substrate is connected to the back side of the circuit board with the conductive adhesive or the adhesive, and the external connection disposed on the circuit board. Since the external connection electrode is extended to the back of the module by connecting the through-hole electrode for the frame and the through-hole electrode for external connection of the frame substrate, soldering work is not necessary when the module body is mounted on the side of the module. Since it is easy to do, solderability is certain. Also, the soldering state can be easily confirmed. A small-sized, thin, and lightweight infrared data communication module having a shielding function can be provided.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an infrared data communication module according to an embodiment of the present invention.
FIG. 2 is a perspective view of the frame substrate of FIG.
3 is a rear view of FIG. 1. FIG.
FIG. 4 is a plan view of a conventional infrared data communication module.
5 is a cross-sectional view taken along line AA in FIG.
6 is a rear view of FIG. 4. FIG.
FIG. 7 is a cross-sectional view illustrating the structure of another conventional infrared data communication module.
8 is a cross-sectional view of a main part of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Circuit board 2 Through hole 2a Through hole electrode 3 Light emitting element 4 Light receiving element 5 IC chip 6, 15 Through hole 6a, 15a for external connection External connection electrode (through hole electrode)
7 Translucent resin 10 Shield plate 11 Motherboard 13 Solder 14 Frame substrate 16 Conductive adhesive or adhesive 30 Infrared data communication module

Claims (1)

Conductive patterns formed on the upper and lower surfaces of the substrate having a substantially rectangular plane are electrically connected via through-hole electrodes of through holes formed on the plane of the substrate, and at least on one side surface of the substrate. A circuit board having a through-hole electrode for external connection connected to a wiring pattern such as a printed circuit board, and at least light emission among electronic components such as a light emitting element, a light receiving element, an IC chip and a capacitor on the upper surface side of the circuit board. The element and the light receiving element are mounted, the IC chip is mounted on the lower surface side, and the upper surface of the light emitting element and the light receiving element are resin-sealed with a translucent resin so as to be covered with the hemispherical lens portion, and the lower surface side IC sealed with resin chip with potting resin, an infrared data communication mode, which is a side mounted on a motherboard in the circuit external connecting through-hole formed in the side surface of the substrate In Yuru,
Surrounding the IC chip, a frame substrate having the same outer shape as the circuit substrate is fixed to the lower surface of the circuit substrate with a conductive adhesive or adhesive, and the opening of the frame substrate is closed with a magnetic shield plate so as to cover the IC chip, The frame substrate has an external connection through-hole electrode that communicates with an external connection through-hole electrode formed on the circuit board, and for external connection by connecting the external connection through-hole electrodes of the circuit board and the frame substrate. An infrared data communication module characterized by extending an electrode to the back of the module.

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