JP2001136748A - Electronic device and manufacture of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize reduction in the size of the secondary side of a transformer, namely a rectifying portion, to reduce the size of an electronic device composed of a transformer connected to the power supply and a load connected to the secondary side of such a transformer via a rectifier. SOLUTION: This electronic device is composed of a power supply, a transformer 2 connected in the primary winding to this power supply, and a load 20 connected to the secondary winding 10 of this transformer 2 via a rectifier 3. The rectifier 3 includes a case 1, a plurality of circuit patterns 28, which is made of a metal plate and provided within the case 1, electronic components bridged among a plurality of circuit patterns 28 within the case 1 and the case 1 filled with an insulation resin 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic apparatus having a power supply, a transformer connected to the power supply, and a load connected to a secondary side of the transformer via a rectifier, and a method of manufacturing the same.

[0002]

2. Description of the Related Art The configuration of a conventional electronic device of this type is as follows. That is, the power supply, the transformer having the primary winding connected to the power supply, and the load connected to the secondary winding of the transformer via the rectifier are provided.

[0003]

The above-mentioned conventional electronic equipment has a problem that it is difficult to reduce the size of the transformer and the rectifier, and consequently, the electronic equipment itself is difficult to reduce in size. That is, a rectifier is connected to the secondary winding of the transformer, but in this rectifier part, since it is the secondary side of the transformer,
A sufficient insulation distance is required in the circuit pattern, and as a result, the secondary side of this transformer,
That is, it is difficult to reduce the size of the rectifier, which has a bad influence on the size of the electronic device. Accordingly, it is an object of the present invention to reduce the size of an electronic device by reducing the size of the secondary side of the transformer, that is, the rectifier portion.

[0004]

According to the present invention, there is provided a rectifier comprising: a case; a plurality of metal plate circuit patterns provided in the case; and a plurality of circuits in the case. It is formed by an electronic component bridged between patterns and an insulating resin filled in the case.

[0005] That is, if the circuit patterns forming the rectifier are molded with an insulating resin in this way, a sufficient insulation distance between the circuit patterns can be obtained. As a result, even if the distance between the circuit patterns is reduced. ,
A sufficient insulation distance that does not pose a problem in practical use is formed, and as a result, the size of the rectifier can be reduced, thereby contributing to downsizing of the electronic equipment.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the first aspect of the present invention, a power supply, a transformer having a primary winding connected to the power supply, and a secondary winding of the transformer connected via a rectifier. The rectifier includes a case, a plurality of metal plate circuit patterns provided in the case, an electronic component bridged between the plurality of circuit patterns in the case, and a rectifier in the case. An electronic device having a filled insulating resin, in particular, a circuit pattern constituting a rectifier is molded with an insulating resin in a case, and as a result, a sufficient insulation distance between circuit patterns can be obtained. As a result, the distance between circuit patterns can be reduced to achieve miniaturization, thereby reducing the size of the rectifier portion, thereby contributing to the miniaturization of the electronic device itself. A.

Next, the invention according to claim 2 of the present invention is:
Put the primary winding and secondary winding of the transformer in the case,
2. The electronic device according to claim 1, wherein an outer periphery thereof is covered with an insulating resin, wherein the primary winding and the secondary winding of the transformer are housed in a case forming a rectifier, and the outer periphery is covered with the insulating resin. Thus, an insulating resin for insulating the circuit patterns of the rectifier can improve the insulation characteristics of the primary winding and the secondary winding of the transformer.

Next, according to a third aspect of the present invention, a circuit pattern is formed from a connection portion and a pattern portion of an electronic component.
The electronic device according to claim 1 or 2, wherein the pattern portion is thinner than the connection portion, and further miniaturization can be achieved by making the connection portion thinner than the pattern portion. In other words, the pattern portion of the circuit pattern has an insulating resin interposed therebetween, so that the insulating distance can be secured even if the distance is sufficiently small. If the part is made thinner, it can further contribute to the small size as a whole.

According to a fourth aspect of the present invention, a through hole for inserting a lead wire of an electronic component is provided in the connection portion, and the through hole is concave from the insertion side of the lead wire to the opposite side. Item 3. The electronic device according to Item 3, wherein the through-hole provided in the connection portion of the circuit pattern has a concave shape, so that the lead wire of the electronic component can be easily inserted into the through-hole.

[0010] The invention according to claim 5 comprises a power supply, a transformer having a primary winding connected to the power supply, and a load connected to a secondary winding of the transformer via a rectifier. An electronic device comprising: a case; a plurality of circuit patterns made of a metal plate provided in the case; an electronic component bridged between the plurality of circuit patterns in the case; and an insulating resin filled in the case. In the device, the rectifier forms a lead frame in which a plurality of circuit patterns are connected by a connection pattern, and then connects an electronic component between connection portions of the plurality of circuit patterns, and then connects the plurality of circuit patterns. Then, the lead frame is housed in the case, and then the case is filled with an insulating resin. When a rectifier is formed depending on the process, the circuit patterns are bridged by electronic components, that is, the insulating resin is molded between the other circuit patterns. In this case, a sufficient insulation distance can be obtained. In this way, the process of making the lead frame first, then connecting the lead patterns with electronic components, and removing the unnecessary connection patterns in that state, ensures the insulation distance between the circuit patterns. It is something that can be taken.

Next, according to a sixth aspect of the present invention, a primary terminal and a secondary terminal of a transformer are integrally formed on a lead frame, and the transformer is mounted on the primary terminal and the secondary terminal. 6. The method for manufacturing an electronic device according to claim 5, wherein the circuit pattern of the rectifier and the electronic component are molded with an insulating resin, wherein the rectifier and the transformer are also housed in a case, and molded with the insulating resin in that state. In addition to ensuring the insulation distance between the circuit patterns described above, the insulation of the transformer can be sufficiently obtained.

An embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIGS. 1 and 2, reference numeral 1 denotes a case having an opening on the lower surface side, in which a transformer 2 and a rectifier 3 connected to its secondary side are housed. Resin 4 is filled, and transformer 2 and rectifier 3 are molded with insulating resin 4. That is, as shown in FIG. 3, the rectifier 3 is connected to the secondary side of the transformer 2. FIG. 3 shows an electronic apparatus using the transformer 2 and the rectifier 3 shown in FIGS. Specifically, FIG. 3 shows an example in which the present invention is used for a printer or a copying machine. A full-wave rectifier 6 is connected after a power source 5 and a rectifier circuit comprising a diode 7 and a capacitor 8 on the output side. Is connected. The primary winding 9 of the transformer 2 is connected to the secondary side of the rectifier circuit. The rectifier 3 is connected to the secondary winding 10 of the transformer 2 as described above.
Are connected, the rectifier 3 includes diodes 11 and 12, capacitors 13 and 14, and resistors 15 and 1.
6 is formed. A primary auxiliary winding 17 is provided on the primary side of the transformer 2, and a control circuit 18 is connected to the primary auxiliary winding 17. A switching element 19 is connected to the control circuit 18. The switching element 19 is interposed in the primary winding 9 of the transformer 2, and has a configuration in which a current flows through the primary winding 9 of the transformer 2 by switching of the switching element 19. This switching element 19
Is controlled by the control circuit 18. The control circuit 1
8 is supplied with a control voltage from the output side of the rectifier 3. The voltage at the output side of the rectifier 3 is compared with a reference voltage by the control circuit 18, and when the voltage is higher than the reference voltage, a switching element 19 is provided. To stabilize the power supply to the load 20 by performing an operation to lengthen the time for turning off the switch 20 and, conversely, when the voltage on the output side of the rectifier 3 is low, to increase the on time of the switching element 19. It has become. In FIG. 3, 21, 22, 23, 24, 25, 26 and 27 are terminals.

Next, a method of manufacturing the portion shown in FIG. 2, ie, the portion of the transformer 2 and the rectifier 3, will be described. FIG. 4 shows a circuit pattern for mounting these transformers and rectifiers. First, as shown in FIG.
As shown in FIG. 4, the lead frame is integrally formed of a metal plate made of iron plate and subjected to solder plating or the like. As shown in FIG. 4, the circuit patterns 28 are connected by connection patterns 29. In addition, connection part 3
0 is larger than the circuit pattern 28, and the through hole 31 provided in the connection portion 30
Fourteen lead wires are concave from the insertion side (upper surface) to the opposite side (lower surface). FIG. 5 shows a case where the primary bobbin 32 is integrally formed with the lead frame 33 by integrally forming a resin. In the next FIG. 6, unnecessary portions of the lead frame are cut only around the primary bobbin 32 before applying the primary winding, and then the terminals 21 (22) 23 (24) are bent. The primary winding 9 is wound as shown in FIG. Next, as shown in FIG. 8, the secondary winding is performed after the cylindrical secondary bobbin 36 is fitted around the primary bobbin 32. 3
Reference numerals 4 and 35 are terminals.

FIG. 9 shows a method of manufacturing the rectifier 3.
Will be described.

FIG. 9 shows a structure in which diodes 11 and 12, capacitors 13 and 14, and resistors 15 and 16 are mounted on the rectifier 3 side of a lead frame 33. FIG. 10 shows an unnecessary portion of the lead frame 33 and a portion of the connection pattern 28 cut away. In FIG. 11, the rectifier 3 of FIG.
Is bent 90 degrees, and a core 37 is inserted into the primary bobbin 32.

Then, as shown in FIG. 1 and FIG.
After being mounted inside, the case 1 is filled with an insulating resin 4 and fixed, and insulation measures are taken.

[0018]

As described above, according to the present invention, the size of the transformer and the rectifier can sometimes be reduced in the electronic device, and as a result, the electronic device itself can be reduced in size.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing the internal structure of FIG. 1;

FIG. 3 is a circuit diagram of an electronic device using a transformer and a rectifier according to the present invention.

FIG. 4 is a perspective view showing a lead frame made of a metal plate for forming a circuit pattern for mounting a transformer and a rectifier.

FIG. 5 is a perspective view showing the primary bobbin integrally formed in FIG. 4;

FIG. 6 is a perspective view showing an unnecessary part lead frame around a primary bobbin cut and bent to apply the winding of FIG. 5;

FIG. 7 is a perspective view showing the primary winding shown in FIG. 6;

FIG. 8 is a perspective view showing a state in which a secondary winding is performed after fitting a secondary bobbin to FIG. 7;

FIG. 9 is a perspective view showing that a diode, a capacitor, and a resistor are mounted to configure a rectifier in FIG. 8;

FIG. 10 is a perspective view showing a state in which an unnecessary part of a lead frame and a connection pattern in FIG. 9 are deleted.

FIG. 11 is a perspective view showing a state before the rectifier shown in FIG. 10 is bent and assembled into a final case.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Case 2 Transformer 3 Rectifier 4 Insulating resin 5 Commercial power supply 6 Full-wave rectifier 8 Capacitor 9 Primary winding 10 Secondary winding 11 Diode 12 Diode 13 Capacitor 14 Capacitor 15 Resistance 16 Resistance 17 Primary auxiliary winding 18 Control circuit 19 Switching element Reference Signs List 20 load 21 terminal 22 terminal 23 terminal 24 terminal 25 terminal 26 terminal 27 terminal 28 circuit pattern 29 connection pattern 30 connection part of electronic component 31 through hole 32 primary bobbin 33 lead frame 34 terminal 35 terminal 36 secondary bobbin 37 core

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Tomio Kizaki 1006 Kadoma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Yutaka Miyamoto 1006 Odaka Kadoma Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. F Terms (reference) 5E044 AD05 CA03 5H730 AA15 BB21 CC01 EE06 FD01 ZZ11 ZZ12 ZZ16

Claims (6)

[Claims] 1. A power supply, a transformer having a primary winding connected to the power supply, and a load connected to a secondary winding of the transformer via a rectifier, wherein the rectifier includes a case, An electronic device comprising: a plurality of circuit patterns made of a metal plate provided therein; an electronic component bridged between the plurality of circuit patterns in the case; and an insulating resin filled in the case. 2. The electronic device according to claim 1, wherein a primary winding and a secondary winding of the transformer are housed in a case, and an outer periphery thereof is covered with an insulating resin. 3. The electronic apparatus according to claim 1, wherein the circuit pattern includes a connection portion of the electronic component and the pattern portion, and the pattern portion is thinner than the connection portion. 4. The electronic device according to claim 3, wherein the connecting portion is provided with a through-hole for inserting a lead wire of the electronic component, and the through-hole is concave from the insertion side of the lead wire to the opposite side. 5. A power supply, a transformer having a primary winding connected to the power supply, and a load connected to a secondary winding of the transformer via a rectifier, wherein the rectifier comprises: a case; A plurality of circuit patterns made of metal plate provided in
In an electronic device having an electronic component bridged between a plurality of circuit patterns in the case and an insulating resin filled in the case, the rectifier includes a lead frame in which the plurality of circuit patterns are connected by a connection pattern. Is formed, then the electronic components are connected between the connection portions of the plurality of circuit patterns, then the connection patterns between the plurality of circuit patterns are removed, and then the lead frame is stored in the case, and then the case is inserted into the case. A method for manufacturing an electronic device formed by filling an insulating resin. 6. A primary terminal and a secondary terminal of a transformer are integrally formed on a lead frame, and a transformer is mounted on the primary terminal and the secondary terminal. After that, a circuit pattern of the transformer and a rectifier and an electronic component are insulated in a case. The method for manufacturing an electronic device according to claim 5, wherein the electronic device is molded with a resin.