JPH07202453A - Circuit structure and production thereof - Google Patents

Abstract

PURPOSE:To obtain a high quality small circuit structure by integrally molding a plurality of electronic devices of a thermoplastic resin while exposing the electrode of each device on the same plane thereby eliminating the need of circuit board. CONSTITUTION:Integrated circuit devices, chip resistors and other electronic devices 5 necessary for constituting a circuit are integrally molded of a thermoplastic resin 6, e.g. a liquid crystal polymer, with the electrode 7 of each device 5 being exposed on a same plane. The circuit structure is provided integrally, on one side thereof, with connectors 8 for connecting a part of wiring 9 of each device 5, the circuit structure is reduced in size because it requires no circuit board and contributes to reduce the size of the electronic device. Furthermore, since each device 5 is bonded firmly through the thermoplastic resin while establishing the electrical connection, wiring and connection with other objects are facilitated while enhancing the quality.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit structure which does not use a circuit board and a method for manufacturing the same.

[0002]

2. Description of the Related Art Generally, a circuit board is used as a circuit structure in electronic equipment, and various electronic components are mounted on the circuit board.

FIG. 8 shows an example of a conventional circuit structure. In FIG. 8, reference numeral 1 denotes a circuit board formed by printing a circuit network 3 on the surface of an insulating substrate 2. A conductive adhesive (not shown) such as cream solder is attached to the land portion, the electrode of the electronic component 4 such as an integrated circuit component or a chip resistor is placed in contact with the land portion, and the cream solder is applied by reflow heating or the like. Is melted to bond the electrode of the electronic component 4 and the land portion of the circuit board 1 to each other.

[0004]

By the way, miniaturization of electronic equipment is being promoted, and there is a demand for a circuit configuration body to be as small as possible. In addition to miniaturization of the electronic component 4, mounting on the circuit board 1 is required. Although the density is increased, there is a limit to the miniaturization and high packaging density of the electronic components 4, and the circuit board 1 having the required thickness and size is a major factor that hinders the miniaturization of the circuit structure. There is. In addition, as an electronic device, a housing occupies a large volume, and is targeted for improvement in downsizing.

Functionally, since the circuit component is heated to a high temperature during the reflow soldering described above, each electronic component must be configured to withstand the high temperature, and the circuit board may be bent by the heating. However, there is a problem that it causes a connection failure with an electronic component to be mounted by causing distortion.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a small-sized and high-quality circuit structure which does not require a circuit board and a manufacturing method thereof.

[0007]

In order to achieve the above-mentioned object, the present invention is to mold a plurality of electronic components by molding with a thermoplastic resin to integrate them, and to expose the electrodes of each electronic component on the same plane. And the circuit structure.

According to the present invention, a plurality of electronic components are mounted on a plate so that their electrodes are in contact with the plate surface, and a thermoplastic molding material is adhered on each of the electronic components so that each electronic component is mounted. Is integrated with the mold, and then the plate is separated to produce a circuit structure.

[0009]

The circuit structure having the above structure is miniaturized because it is configured as a circuit board, and the electrodes are arranged so as to be flush with each other. Therefore, it is easy to print a circuit network or wire wiring.

Further, since the circuit board is not used in the method for manufacturing the circuit structure, there is no heating step in reflow soldering, there is no fear of heat loss of electronic parts, and the electrodes of each circuit part are flush with each other. Therefore, the subsequent wiring is facilitated.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A circuit structure according to an embodiment of the present invention will be described below. As shown in FIGS. 1 and 2, integrated circuit components, chip resistors, and other electronic components 5 necessary for the circuit configuration are molded and integrated with a thermoplastic resin 6, for example, a liquid crystal polymer. The electrodes 7 are arranged so as to be exposed on the same surface. A connector 8 is integrally provided on one side of the circuit structure, and a part of the wiring wire 9 of each electronic component 5 is connected to the connector 8.

Since the circuit structure having this structure does not have a circuit board, the shape of the circuit structure is miniaturized, which helps miniaturize the electronic equipment. Further, since each electronic component 5 is firmly fixed in position by the thermoplastic resin 6 and the electrical connection is established, wiring or connection to another connecting body is easy and the quality is improved.

FIG. 3 shows another embodiment of the present invention, in which a heat dissipation layer 10 is formed on a thermoplastic resin 6 in which each electronic component 5 is molded by secondary molding using a heat dissipation material having good heat conductivity. is doing.

In addition to the above-mentioned embodiment, this can improve the heat dissipation characteristics of the circuit structure, and the heat dissipation layer 10 can be easily formed by molding. 4 and 5 show another example of the heat dissipation structure of the circuit structure of the present invention. In FIG. 4, a heat dissipation plate 11 is attached instead of the above heat dissipation layer, and in FIG. Similarly, a cooling fin 12 is attached to each electronic component 5 in place of the heat dissipation layer.
2 is derived to the outside. Similar to those provided with a heat dissipation layer, these can enhance the heat dissipation effect, and the heat dissipation plate 11 or the cooling fin 1 can be used.
2 is securely adhered to the thermoplastic resin 6 and is also wrapped and held, so that a stable heat dissipation structure can be obtained.

FIG. 6 also shows another embodiment of the present invention in which the molding material of each electronic component 5 is a case 13 of an electronic device.
Has become According to this configuration, since the case 13 is a circuit structure body and there is no circuit board, it is possible to further promote the miniaturization of the electronic device and particularly reduce the number of parts, which is useful.

Next, a method of manufacturing the circuit structure of the present invention will be described. First, as shown in FIG. 7 (a), a double-sided adhesive tape 15 is attached onto a metal plate 14, and the electronic parts 5 having electrodes exposed on their end faces are attached to the exposed surface of the double-sided adhesive tape 15. Mount so that the electrodes are in contact. Next, as shown in FIG. 2B, the thermoplastic resin 6 is molded over the entire electronic components 5. Further, as shown in FIG. 3C, a heat dissipation layer 10 made of a resin having good thermal conductivity mixed with metal powder or the like is formed on the molded thermoplastic resin 6 by secondary molding. Then, as the final step, the double-sided adhesive tape 15 is removed from the plate 14 and the electrode-side surface of the electronic component 5, as shown in FIG.

In this manufacturing method, since the circuit board is not used, there is no step of mounting the electronic component 5 on the circuit board, and the so-called molded structure facilitates manufacturing, and the electronic component 5 is fixed. Since no reflow soldering is required, each electronic component 5 is not required to have large heat resistance,
Of course there is no heat damage.

The circuit structure thus obtained is provided with printed wiring or wire wiring on its electrodes for use. Further, the thermoplastic resin as the molding material may be other than the liquid crystal polymer, and the point is that the thermoplastic resin has a function of sealing the electronic component.

[0019]

As is clear from the description of the above embodiment,
Since the present invention is a circuit structure having a configuration in which each electronic component is molded without using a circuit board, and each electrode thereof is exposed and arranged on the same surface, the circuit structure can be miniaturized,
Contributes to miniaturization of electronic devices. Further, the present invention is a manufacturing method in which the electronic components are molded on the plate so that the respective electrodes are in contact with the plate, and the respective electronic components are integrated, so that the integration of the electronic components is easy. In addition, heating such as reflow is not necessary for fixing the electronic components, and each electronic component is not damaged by heat.

[Brief description of drawings]

FIG. 1 is a perspective view of a circuit structure according to an embodiment of the present invention.

FIG. 2 is a sectional view of the same circuit structure.

FIG. 3 is a sectional view of a circuit structure according to another embodiment of the present invention.

FIG. 4 is a sectional view of a circuit structure according to another embodiment of the present invention.

FIG. 5 is a sectional view of a circuit structure according to another embodiment of the present invention.

FIG. 6 is a sectional view of a circuit structure according to another embodiment of the present invention.

FIG. 7 is a manufacturing process diagram of a circuit structure according to an embodiment of the present invention.

FIG. 8 is a perspective view of a conventional circuit structure.

[Explanation of symbols]

 5 electronic parts 6 thermoplastic resin 7 electrode 8 connector 9 wire 10 heat dissipation layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiaki Sugimura 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (9)

[Claims] 1. A circuit configuration body in which a plurality of electronic components are molded by a thermoplastic resin to be integrated with each other, and electrodes of the respective electronic components are exposed and arranged on the same plane. 2. The circuit structure according to claim 1, wherein a heat dissipation layer made of a heat dissipation material is formed on the molded thermoplastic resin. 3. The circuit structure according to claim 1, wherein the connector is molded and integrated. 4. The circuit structure according to claim 1, wherein a heat dissipation plate is bonded onto the molded thermoplastic resin. 5. The electronic component is provided with a cooling fin, and the cooling fin is exposed from a mold thermoplastic resin.
The described circuit structure. 6. The circuit structure according to claim 1, wherein the molded thermoplastic resin forms a case. 7. A plurality of electronic components are mounted on a plate such that their electrodes are in contact with the surface of the plate, and a thermoplastic molding material is adhered to each of the electronic components to integrally mold the electronic components. A method of manufacturing a circuit structure, wherein the plate is separated and then the plate is separated. 8. A double-sided adhesive tape is bonded onto the plate,
A plurality of electronic components are mounted on the double-sided adhesive tape so that their electrodes are in contact with the surfaces of the double-sided adhesive tape, and a thermoplastic molding material is adhered onto the respective electronic components to integrally mold the electronic components. A method of manufacturing a circuit structure in which the double-sided adhesive is peeled off from the surface of the plate and the electrode side of each electronic component. 9. The method for manufacturing a circuit structure according to claim 7, wherein a heat radiation layer is formed by secondarily molding a molding material having good thermal conductivity on the thermoplastic molding material.