JP2591152Y2 - Electronic component mounting circuit board - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an electronic component mounted circuit board used in electronic equipment and the like, and more particularly to a substrate structure in which a resin for protecting chip components can be easily coated.

[0002]

2. Description of the Related Art Conventionally, as a method of mounting electronic components on a printed wiring board with an increased degree of integration, there is a method of using a dedicated integrated circuit or a hybrid integrated circuit, but the degree of integration is relatively low. In the case of small-volume production, the cost increases. As a countermeasure, a small ceramic or
A wiring pattern is formed on a glass epoxy board, and a plurality of electronic circuit components such as a bare chip and a mold chip are mounted thereon. After wire bonding and soldering, an electronic component mounting circuit board with lead terminals is mounted. There is a method of mounting on a printed wiring board.

FIG. 3 is a configuration diagram of a conventional electronic component mounting circuit board. Hereinafter, description will be made with reference to the drawings. Reference numeral 1 denotes a substrate on which a wiring pattern is formed on a plate made of glass epoxy, ceramic, or the like, and a terminal pattern 11 coated with solder is provided on a peripheral portion. Reference numeral 2 denotes a lead terminal, which has a U-shaped fitting portion 21 inserted into the terminal pattern 11 at the peripheral portion of the substrate 1 at one end, and a terminal portion 22 soldered to the printed board at the other end. 3 is a mold chip
A chip-shaped electronic element such as a diode or a capacitor is molded with resin, and a terminal is provided outside. A bare chip 4 has a bare chip such as an IC mounted on the substrate 1 and wire-bonded. 5 is a coating resin layer, and a thermosetting resin such as an epoxy resin is a bare chip 4.
And is applied to the wire bonding section 41 and cured.

FIG. 4 is a view showing a mounting process of a conventional electronic component mounting circuit board. Hereinafter, the component mounting process will be described with reference to the drawings. (A) Paste solder is printed on the B side of the substrate 1, the mold chip 3 is mounted thereon, and a U-shaped fitting portion 21 of the lead terminal 2 is provided on the terminal portion 11 of the substrate 1. The molded chip 3 is soldered by a heating means such as infrared rays, and the terminal portion 11 and the fitting portion 21 are fixed. After that, the substrate 1 is inverted. This inverted state is shown in the figure.

(B) The mold chip 3 is mounted on the inverted surface A of the substrate 1 by the same method, and reflowed and cleaned. (C) The bare chip 4 is die-bonded to a predetermined position on the surface A of the substrate 1 with an adhesive or the like, and subsequently, the terminal portion (not shown) of the bare chip 4 and the terminal portion (not shown) of the substrate 1
Is wire-bonded with a gold wire or the like.

(D) A coating resin layer 5 such as epoxy is applied to the wire-bonded bare chip 4 in order to prevent contamination and secure the strength of the wire bonding portion 41, and is cured by ultraviolet light or heating to form an electronic component mounted circuit board. Is completed.

[0007]

In the mounting process of the electronic component mounting circuit board shown in FIG. 4, when the viscosity of the coating liquid is low, the bare chip 4 and the wire bonding portion 4
Since the coating resin 5 that protects 1 flows to an unnecessary part, not only the appearance is poor in shape but also the upper part of the wire may be exposed. Further, the bare chip 4 itself is easily exposed, so that the IC part is deteriorated and the reliability quality of the wire bonding part 41 is impaired. Conversely, if the viscosity is high, air pockets are likely to be generated around the chip 4, and when this occurs, there is a possibility that cracks or wire breaks in the coating resin layer 5 may occur due to expansion or the like. Accordingly, in the case of a resin, in particular, not only the control of the amount to be applied but also the control of the viscosity related to the fluidity of the resin are required. As a countermeasure, a method has been proposed in which a partition is provided around the bare chip 4 to which the wire bonding is performed so that the applied coating resin layer 5 having a low viscosity does not flow. However, this method has a problem that the number of steps is increased. There is also a method of mounting a bare chip and resin molding using a dedicated mold (lead frame, resin molding mold) as in a normal integrated circuit. This method has a problem that it is not suitable for high-mix low-volume production and the price is high. Therefore, the present invention facilitates the resin forming operation. Reduce the number of mounting steps. Lower costs. It is an object of the present invention to provide a structure of an electronic component mounted circuit board that solves these problems at the same time.

[0008]

According to the present invention, there is provided an electronic component mounting circuit board comprising an electronic component mounted on a substrate and a resin applied to the electronic component. A conductive part, and a terminal integrally formed with the partition wall for preventing the resin from flowing out is attached to the conductive part.

[0009]

According to the present invention, since the terminal is integrated with the resin outflow preventing partition, the terminal mounting step and the outflow preventing step are performed simultaneously. And when the resin is applied in the mounted state, the resin is prevented from flowing out by the wall,
The height of the resin can be increased, and the electronic components can be covered sufficiently.

[0010]

FIG. 1 is a block diagram of an electronic component mounting circuit board according to an embodiment of the present invention. Hereinafter, description will be made with reference to the drawings. Reference numeral 1 denotes a substrate on which a wiring pattern is formed on a plate made of glass epoxy, ceramic, or the like, and a terminal pattern 1 on which a soldering process (solder is applied) before the process is performed in a peripheral portion.
1 (conductive portion) is provided. Reference numeral 3 denotes a molded chip, in which a chip-shaped electronic element such as a diode or a capacitor is molded with a resin, and external terminals are provided. A bare chip 4 has a bare chip such as an IC mounted on the substrate 1 and wire-bonded. Reference numeral 6 denotes a connector, in which a molded portion 64 made of a heat-resistant resin such as polycarbonate and a lead terminal 61 are integrally formed. One end of the lead terminal 61 is inserted into the terminal pattern 11 in the peripheral portion of the substrate 1. It has a U-shaped fitting part 62 and a terminal part 63 at the other end which is soldered to a printed circuit board.

Here, the connector 6 will be supplementarily described. In FIG. 1, both ends of the connector 6 are wedge-shaped at 45 °, but this is for abutting the substrate 1 like a frame. Further, in FIG. 1, in the case of a square substrate, the length x of one side of the substrate 1
And the length y of the concave portion of the connector 6 fitted corresponding to this side is equal, so that the four connectors 6 are fitted to the board 1 without any gap. In this case, the connectors (four) for each side of the board have the same shape. Further, the connector may be formed so that the length y is equal to the length x even if the substrate is rectangular.

The shape of this end is intended to sandwich the board 1 so that there is no gap between the contact portions of the adjacent connectors 6, and may be a right angle. Alternatively, a connector 6 having a dedicated number of terminals may be formed, or a versatile long connector may be formed and cut according to the dimensions of the substrate 1. When the terminal pattern 11 and the fitting portion 62 are attached in a corresponding position,
As shown in (b), the connector ends are brought into close contact with each other. Further, the fitting portion 62 is in a state of being crimped to the pattern 11, the thickness of the pattern 11 and the fitting portion 62 is small, and the gap between the board 1 and the connector 6 is small. Thus, the resin can be prevented from flowing outside the substrate.

FIG. 2 is a mounting process diagram of an electronic component mounting circuit board according to an embodiment of the present invention. Hereinafter, the component mounting process will be described with reference to the drawings. (A) Paste solder is printed on the B side of the substrate 1, the mold chip 3 is mounted thereon, the connector terminals 64 are further mounted, and the connectors 6 adjacent to the terminal portions 11 on the four sides of the substrate 1 are connected. The U-shaped fitting portion 62 of the connector 6 is inserted so that the gaps are brought into close contact with each other, and a is shown in FIG.
And b are aligned. The mold chip 3 is soldered only on the B side by infrared heating means (intensive heating within a certain range), and the solder of the terminal portion 11 that has been pre-soldered is melted and fixed to the fitting portion 62. . Thereby, the terminal attaching step and the wall attaching step are performed simultaneously. After that, the substrate 1 is inverted. This inverted state is shown in the figure.

(B) The mold chip 3 is mounted on the inverted surface A of the substrate 1 in the same manner, and the mold chip 3 is mounted only on the surface A by infrared heating means (intensive heating within a certain range). Are soldered and the solder of the terminal portion 11 which has been pre-soldered is melted, and the fitting portion 62 is melted.
Is fixed. After that, it is washed. (C) The bare chip 4 is die-bonded to a predetermined position on the surface A of the substrate 1 with a silver epoxy adhesive or the like, and subsequently,
A terminal portion (not shown) of the bare chip 4 and a terminal portion (not shown) of the substrate 1 are wire-bonded with a gold wire or the like.

(D) In order to prevent contamination and ensure the strength of the wire bonding portion 41, the bare chip 4 wire-bonded is filled with a low-viscosity resin, such as epoxy, in a partition formed by the mold portion 64 of the connector 6. (Because the resin does not flow out, the resin can be thickened unilaterally), the coating resin layer 7 is cured by ultraviolet light or heating, and the electronic component mounted circuit board is completed. The thickness of the resin is sufficiently higher than the chip, and the chip can be completely protected. The reliability is improved on the back surface (surface B) by applying or spraying the moisture-resistant coating resin film 8 thinly. The resin on the A side is in a state of being formed into a square shape, and the shape of the resin has a good appearance.

In the above embodiment, the double-sided mounting board is described. However, the present invention can be applied to a single-sided mounting board. As described above, in the present embodiment, the mold portion 64 of the connector 6 is used.
Plays a role of a partition for preventing the coating resin layer 7 from flowing out, so that it is not necessary to control the application amount and the viscosity of the coating resin layer 7.

[0017]

[Effect of the Invention] As described above, in the present invention, by using a connector integrally formed with a lead terminal,
The resin forming work for covering the electronic component is facilitated, so that the number of mounting steps and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an electronic component mounting circuit board according to an embodiment of the present invention.

FIG. 2 is a mounting process diagram of an electronic component mounting circuit board according to an embodiment of the present invention;

FIG. 3 is a configuration diagram of a conventional electronic component mounting circuit board.

FIG. 4 is a mounting process diagram of a conventional electronic component mounting circuit board.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... Lead terminal 3 ... Mold chip 4 ... Bare chip 5, 7 ... Coating resin layer 8 ... Coating resin film 6 ... Connector

Claims (1)

(57) [Scope of request for utility model registration] 1. An electronic component mounted circuit board having an electronic component mounted on a substrate and a resin applied to the electronic component, wherein a conductive portion is provided on a periphery of the substrate, and the resin flows into the conductive portion. An electronic component mounting circuit board, comprising a terminal integrally formed with a prevention partition.