JPH11354976A - Smd driver module for el and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an SDM driver module for EL, and a manufacturing method thereof, in which a coil itself is a closed magnetic path generating no field noise to the outside and external electromagnetic noise has no effect thereon. SOLUTION: A boost drive circuit for EL emission substrate comprising electronic parts, e.g. a drive IC 34, a closed magnetic path type tubular coil 5 and a chip capacitor 32, is mounted on a circuit board 11 to constitute an SDM driver module for EL 20. The circuit board 11 is provided in the outer periphery with an opening 12 for containing the closed magnetic path type tubular coil 5 and a plurality of connection terminals 33a, 33b (input) and 35a, 35b (output) having throughholes 14. The connection terminals are connected with the ends of the coil 5 and the electronic parts are coated with sealing resin 13. Since a coil shielded with a tubular bobbin is used for EL, the coil itself is a closed magnetic path generating no field noise to the outside and external electromagnetic noise has no effect thereon. Consequently, reliability is enhanced while reducing the size and thickness and cost is reduced by increasing the yield.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a portable telephone, a PHS,
The present invention relates to an SMD driver module for an EL as a surface-mounted device (SMD) for emitting an EL (electroluminescence) element used for a backlight of a liquid crystal display device such as a communication device or a timepiece, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, cellular phones, PHSs, communication devices,
2. Description of the Related Art An EL driver module has been widely used to emit light from an EL element used for a backlight of a liquid crystal display device such as a timepiece. As shown in FIG. 11, a typical circuit diagram of this EL driver module has a function of converting a DC voltage to a required frequency, boosting the voltage, and driving the EL light emitting substrate. In the circuit 30 of the EL driver module, electronic components such as an inductance element 31, an active element 34, a chip capacitor 32, and a step-up transformer (not shown) are connected on a circuit board, and input terminals 33a and 33b are connected to a DC power supply 3.
3 is configured by connecting the EL element 36 to the output terminals 35a and 35b. At this time, with the trend of miniaturization and thinning of the product, the EL driver module having the circuit board on which the electronic components are mounted and the connection terminals are provided has also been developed as a technology for miniaturizing and thinning the surface. There is a strong demand for device implementation.

The technology of an SMD driver module for EL is disclosed in Japanese Patent Application No. 8-356428 (filed on Dec. 26, 1996) previously filed by the present applicant. The outline will be described below with reference to the drawings.

FIG. 10 is a perspective view of an SMD driver module for EL. Reference numeral 10 denotes an EL SMD driver module, which is an electronic component surface-mounted on a circuit board 11 made of glass epoxy resin or the like, that is, an inductance element 31 having an open magnetic circuit, and a drive IC 3 as an active element.
4. It is constituted by wiring (not shown) of the chip capacitor 32. The inductance element 31 is housed in the opening 12 formed at a predetermined position of the circuit board 11 and has a small mounting thickness as a whole. The circuit board 1
1, a plurality of connection terminals having through holes on the outer periphery are formed, and input terminals 33a and 33b, output terminals 35a,
35b is configured. The SMD driver module 10 for EL is configured by covering the entire surface of the electronic component mounted on the circuit board 11 with a thermosetting sealing resin 13.

[0005]

However, the aforementioned SMD driver module for EL has the following problems. That is, since the inductance element is an open magnetic path in which the coil is not shielded,
When the coil is driven, the magnetic field noise generated by the coil itself has a magnetic effect on surrounding electronic components, and becomes a source of the magnetic field noise. On the other hand, there is a drawback that the coil performance is affected because it is also affected by external electromagnetic noise.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to form a closed magnetic circuit by press-fitting an iron core coil into a cylindrical bobbin made of a metal magnetic material. SMD driver for EL, which uses a closed magnetic circuit type cylindrical coil that does not easily affect noise to the EL, does not emit magnetic field noise outside the closed magnetic circuit, and is not affected by external electromagnetic noise. A module and a method for manufacturing the module are provided.

[0007]

In order to achieve the above object, an SMD driver module for EL according to the present invention comprises a step-up drive for an EL light emitting substrate comprising electronic components such as an active element, an inductance element and a chip capacitor. In an SMD driver module for EL in which a circuit is mounted on a circuit board, an electronic component storage portion for storing the electronic component on the circuit board, and a plurality of connection terminals having through holes on the outer periphery of the circuit board are provided. A terminal of a closed magnetic circuit type cylindrical coil constituting an inductance element is connected to a terminal, and the electronic component is covered with a sealing resin.

The closed magnetic circuit type cylindrical coil has a core portion formed by winding a predetermined number of turns around a rod-shaped coil core made of a magnetic material such as permalloy, and this core portion is formed into a bottomed cylindrical bobbin. A closed magnetic circuit is formed by press-fitting and fixing.

Further, according to the present invention, there is provided a method of manufacturing an EL SMD driver module, comprising: a step-up driving circuit for an EL light emitting substrate comprising electronic components such as an active element, an inductance element and a chip capacitor mounted on a circuit board. In the method of manufacturing the SMD driver module for use, a plurality of rows of openings for accommodating a plurality of tubular bobbins of a closed magnetic circuit type tubular coil are formed on a plane of a collective circuit board made of glass epoxy resin or the like from which a large number of pieces are taken; A collective circuit board processing step of forming a plurality of through holes for connection of an upper surface electrode pattern between the columns, and a plating step of forming a plating layer on the entire surface of the collective circuit board including the inner surface of the through hole by plating Add a plating resist, expose and develop with a pattern mask, perform pattern etching,
An upper electrode pattern of the collective circuit board, an electrode pattern forming step of forming a through-hole electrode in the through-hole, a closed magnetic circuit type cylindrical coil in an opening formed in the collective circuit board, further comprising an active element, An electronic component supplying step of positioning and supplying an electronic component such as a chip capacitor at a predetermined position, a mounting step of soldering the electronic component to an electrode pattern, and connecting the electronic component by a fixing and connecting means such as thermocompression bonding and wire bonding; Place a mold for resin molding on the circuit board, fill it with sealing resin such as ethoxy, cure it,
A resin encapsulating step of curing the filling encapsulating resin, and a single dicing machine or slicing machine cutting along two orthogonal cut lines passing through substantially the center of the through hole of the collective circuit board to form a single EL SMD And a cutting step of dividing into driver modules.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an SMD driver module for EL and a method of manufacturing the same according to the present invention will be described with reference to the drawings. 1 to 6 relate to an SMD driver module for EL according to an embodiment of the present invention, and FIG. 1 is a perspective view of the SMD driver module for EL. FIG. 2 is a sectional view taken along line AA of FIG. FIG. 3 is a sectional view of a closed magnetic circuit type tubular coil. FIG. 4 is a front view of a coil core. FIG. 5 is a front view of a core showing a coil winding in cross section. FIG. 6 is a sectional view of the cylindrical bobbin. 7 to 9 relate to a manufacturing method.
FIG. 7 is a partially enlarged perspective view showing a processing step of forming an integrated circuit board and a step of forming an electrode pattern. FIG. 8 is a partially enlarged perspective view showing a process of supplying and mounting an electronic component. FIG. 9 is a partially enlarged perspective view showing a resin sealing step and a dicing step. In the drawings, the same members as those of the prior art are denoted by the same reference numerals.

In FIGS. 1 and 2, reference numeral 20 denotes an SM for EL.
D driver module. Opening 12 made of glass epoxy resin or the like and accommodating closed magnetic circuit type tubular coil 5
And electronic components surface-mounted on the circuit board 11, that is, wiring connections (not shown) of the closed magnetic circuit type tubular coil 5 as an inductance element, the chip capacitor 32, and the drive IC 34 as an active element. Be composed. The circuit board 11 is formed with a plurality of through-holes on the outer periphery, for example, two pairs of connection terminals in FIG. 1, and input terminals 33a and 33b and output terminals 35a and 35b.
Is provided. The electronic components mounted on the circuit board 11 are covered with a sealing resin 13 such as an epoxy resin.
The circuit connection of the EL SMD driver module 20 is the same as that in FIG.

The structure of the closed magnetic circuit type tubular coil 5 is shown in FIG.
As shown in FIG. 5, reference numeral 2 denotes a coil core, which is made of a magnetic material such as permalloy, and has flanges 2a and 2b formed at both ends thereof, and slits 2c for processing coil ends in the flanges 2a and 2b, respectively. Have been. Reference numeral 3 denotes a coil having a coil portion 3a formed by winding the coil 3 by a predetermined number of turns while leaving the flange portions 2a and 2b on the coil core 2. The winding start terminal 3b and the winding end terminal 3c of the coil portion 3a are connected to the slit 2c.
The core unit 1 is configured by performing terminal processing by guiding to the core unit 1.

As shown in FIG. 4, the outer diameter D1 of the first flange 2a on the bottom side of the tubular bobbin, which will be described later, is set, for example, between the two flanges 2a and 2b formed on the coil core 2. About 2.0
mm and the outer diameter D2 of the second flange 2b on the opening side are set to, for example, approximately 2.2 mm. That is, by setting D2> D1, it is possible to smoothly guide the press-fitting at the time of fitting at the throttle portion of the cylindrical bobbin described later.

As shown in FIGS. 3 and 6, reference numeral 4 denotes a cylindrical bobbin made of a metal magnetic material such as permalloy or iron having a thickness of, for example, about 0.1 to 0.2 mm. The cylindrical bobbin 4 is a bottomed cylindrical case into which the core 1 is inserted, and narrowed portions 4a, 4b convex on the inner diameter side of the cylindrical portion are provided at both end flanges 2a, 2b of the core 1. It is formed at a position corresponding to the contact. The inner diameters of the narrowing portions 4a, 4b are set so as to be pressed into and fixed to both end flange portions 2a, 2b of the core portion 1. Therefore, as shown in FIG.
By press-fitting the core 1 from the first flange 2a side, as described above, there is a slight difference in the outer diameters of the two flanges. , 4b
Are fitted with the flanges 2a and 2b of the core 1, respectively, and the substantially closed-type closed magnetic path type tubular coil 5 is completed.

A method of manufacturing an EL SMD driver module having the above configuration will be described. In FIG. 7, reference numeral 11A denotes a collective circuit board made of a glass epoxy resin or the like for taking a large number of pieces. The processing step of the collective circuit board 11A includes forming a plurality of rows of openings 12 for accommodating the cylindrical bobbins 4 of the plurality of closed magnetic circuit type tubular coils 5 at predetermined positions on the plane of the collective circuit board 11A. A plurality of through holes 14 are formed between each of the 12 rows by processing means such as NC cutting or pressing. The through holes 14 between the rows are
It is formed on a cut line described later.

Next, in the electrode pattern forming step, after cleaning the entire surface of the collective circuit board 11A, a copper plating layer is formed on the entire surface by electroless plating, and a plating resist is added in the etching process. Exposure and development are performed using a pattern mask to form an upper electrode pattern 15a and a lower electrode pattern 15b (FIG. 2) of the collective circuit board 11A. At the same time, a plurality of connection terminals are formed in the through hole 14, and input terminals 33a and 33b and output terminals 35a and 35b are provided. Electronic components such as a closed magnetic circuit type cylindrical coil 5 mounted on a circuit board, which will be described later, a drive IC 34, a chip capacitor 32, and a step-up transformer (not shown) are connected, DC power is supplied to input terminals 33a and 33b, and output terminals 35a and An EL element is connected to 35b. A nickel plating layer is formed by electrolytic plating on the electrode pattern thus formed, and a gold plating layer is further formed thereon by electrolytic plating to complete the electrode pattern.

In FIG. 8, in the supply step of the electronic components, the closed magnetic circuit type tubular coil 5 is supplied to a predetermined position of the collective circuit board 11A, for example, the opening 12 by an automatic mounting machine or manually in the same direction and positioned. . The other driving ICs 34 and chip capacitors 32 are also supplied to predetermined positions. Next, the mounting step is to attach the terminals 3b, 3c of the closed magnetic circuit type tubular coil 5 to the upper surface electrode pattern 15a formed on the collective circuit board 11A.
Is connected to the drive IC 34 by soldering or thermocompression bonding.
Are connected by wire bonding, and the chip capacitor 32 is connected by connection / fixing means such as soldering.

The opening 12 of the collective circuit board 11A
When positioning and fixing the closed magnetic circuit type tubular coil 5 to the lower surface of the circuit board 11A, an adhesive sheet (not shown) is attached in advance to the lower surface of the integrated circuit board 11A, and the cylindrical bobbin 4 of the closed magnetic circuit type tubular coil 5 is attached to the adhesive sheet surface. It may be positioned.

In FIG. 9, in the resin sealing step, first, a resin molding frame (not shown) is arranged so that the sealing resin 13 is not filled in the through hole 14 at the time of supplying the resin. Is filled with the sealing resin 13. Instead of placing the mold for resin molding, the periphery may be surrounded by tape. After the sealing resin 13 is injected, it is cured and the filling sealing resin is cured. After the sealing resin 13 is injected, a plate-like member (not shown) is placed on the upper surface of the cylindrical bobbin 4 of the closed magnetic circuit type cylindrical coil 5 so that the surface of the filled internal resin can be made uniform. good. The resin amount of the sealing resin 13 is filled so that a part of the cylindrical bobbin 4 of the closed magnetic circuit type cylindrical coil 5 is flush with the resin or slightly exposed.

Next, in the dicing step, after the sealing resin 13 is cured, when the resin molding frame and the plate-like member are used, they are removed, and the dicing machine or the slicing machine is used to remove the through-hole of the collective circuit board 11A. 14 are cut along two orthogonal cut lines passing through substantially the center, that is, a cut line 15 in the X direction and a cut line 16 in the Y direction, and are divided into a single EL SMD driver module 20.

As described above, when an adhesive sheet is attached to the lower surface of the collective circuit board 11A, the adhesive sheet may be left as it is on the lower surface side of the EL SMD driver module 20. To prevent short circuit with the motherboard wiring pattern when mounted on the motherboard.
In addition, if the adhesive sheet is colored when sorting the front and back of the finished product, it is easy to sort by the sensor.

[0022]

As described above, according to the present invention,
In particular, by using a closed magnetic circuit type cylindrical coil with a shielding measure with a cylindrical bobbin for EL, the coil itself does not emit magnetic field noise to the outside in the closed magnetic circuit and is affected by external electromagnetic noise. There is no S for EL
The reliability of the MD driver module is improved. Furthermore,
By performing each process of substrate processing, electrode pattern formation, electronic component supply / mounting, resin encapsulation and dicing in the state of a collective circuit board that takes many pieces, the productivity is good and the thickness compared to conventional products It can be made compact and thin over all widths and lengths, and can be satisfactorily used as an electronic component that is light and thin. Inexpensive EL SMD with excellent reliability
A driver module and a method for manufacturing the same can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view of an EL SMD driver module according to an embodiment of the present invention.

FIG. 2 is a diagram showing an A of the SMD driver module for EL shown in FIG.
FIG. 4 is a cross-sectional view taken along a line A.

FIG. 3 is a sectional view of the closed magnetic circuit type tubular coil mounted in FIG. 1;

FIG. 4 is a front view of the coil core of FIG. 3;

5 is a front view of a core portion in which a coil is wound around the coil core of FIG. 4 and the coil winding is shown in a cross section.

FIG. 6 is a sectional view of the cylindrical bobbin of FIG. 3;

FIG. 7 is a partially enlarged perspective view showing a process of processing a collective circuit substrate and a process of forming an electrode pattern in the method of manufacturing an SMD driver module for EL of the present invention.

8 is a partially enlarged perspective view showing a process of supplying and mounting electronic components on the collective circuit board of FIG. 7;

FIG. 9 is a partially enlarged perspective view showing a resin sealing and dicing step in FIG.

FIG. 10 is a perspective view of a conventional EL SMD driver module.

FIG. 11 is a typical circuit configuration diagram of an EL driver module.

[Explanation of symbols]

 Reference Signs List 4 cylindrical bobbin 5 closed magnetic circuit type cylindrical coil 11 circuit board 11A collective circuit board 12 opening 13 sealing resin 14 through hole 15 cut line in X direction 16 cut line in Y direction 20 EL SMD driver module 32 chip capacitor 33a , 33b input terminal 34 drive IC 35a, 35b output terminal

Claims (3)

[Claims] 1. An EL SMD driver module in which a step-up drive circuit for an EL light-emitting substrate comprising electronic components such as an active element, an inductance element and a chip capacitor is mounted on a circuit board. And a plurality of connection terminals having through holes on the outer periphery of the circuit board, and a terminal of a closed magnetic circuit type cylindrical coil forming an inductance element is connected to the connection terminals, An SMD driver module for EL, characterized by covering with a sealing resin. 2. The closed magnetic circuit type cylindrical coil has a core portion formed by winding a predetermined number of turns around a rod-shaped coil core made of a magnetic material such as permalloy, and this core portion is formed into a bottomed cylindrical bobbin. 2. The EL SMD driver module according to claim 1, wherein the closed magnetic circuit is formed by press-fitting and fixing. 3. A method for manufacturing an EL SMD driver module in which a step-up drive circuit for an EL light-emitting substrate, which is composed of electronic components such as an active element, an inductance element, and a chip capacitor, is mounted on a circuit board. A plurality of openings for accommodating a plurality of tubular bobbins of a closed magnetic circuit type tubular coil are formed in a plurality of rows on a plane of a collective circuit board made of glass epoxy resin or the like, and a plurality of openings for connecting an upper surface electrode pattern are provided between the respective rows. A collective circuit board processing step of forming a through-hole, a plating step of forming a plating layer on the entire surface of the collective circuit board including an inner surface of the through-hole by plating, a plating resist is added, and a pattern mask is exposed and developed. Then, pattern etching is performed to form a through-hole electrode in the upper electrode pattern of the collective circuit board and the through-hole. An electrode pattern forming step to be formed, and an electronic component supplying step of positioning and supplying an electronic component such as an active element and a chip capacitor at a predetermined position with a closed magnetic circuit type tubular coil in an opening formed in the collective circuit board. When,
Soldering the electronic component to the electrode pattern, a mounting step of connecting with fixing and connecting means such as thermocompression bonding and wire bonding, and disposing a resin molding form on the collective circuit board, and sealing resin such as ethoxy. Filling, curing, and filling the resin with a resin sealing step of hardening the sealing resin, and cutting along two orthogonal cut lines passing through a substantially central portion of the through hole of the collective circuit board with a dicing machine or a sling machine. A method for manufacturing an EL SMD driver module, comprising: a cutting step of dividing the EL SMD driver module into single EL SMD driver modules.