JPS61114593A - Circuitry - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention is directed to a metal base substrate having a core material of metal such as AI or Fe alloy and insulating its surface to constitute a circuit.
This invention relates to a circuit configuration method in which jumper wire connections, circuit opening/closing, etc. are performed by soldering.

[Conventional technical background and its problems] In the wiring boards used in recent consumer devices, there is a need to dissipate heat generated in circuits due to higher density component mounting, and the need for smaller devices. Metal base substrates made of FeltG material are used because the wiring circuit itself is placed directly on the surface of a metal casing, or because of the need for magnetic shielding properties for motor interlocking devices.

The surface of such metal-based substrates is oxidized or insulated with organic resin or ceramics, while the conductor circuit pattern on the substrate is formed by etching in the case of a Cu clad plate, or additively formed on the insulating coating resin. using the law,
In particular, the thick film firing method is commonly used for enamel coated plates.

By the way, a board made of any metal has excellent heat dissipation properties, which means that the temperature of the part of the board to be soldered does not easily rise.

This is not a practical problem when mounting and soldering leadless components on the arranged circuit pattern by using the dipping method in a solder bath or the glue flow method in a reflow oven, but when mounting leadless components on a metal substrate, When attempting to solder by melting solder locally, it is difficult to secure enough heat to raise the temperature of the joint against the board base characteristics that are important for heat diffusion. It is difficult to join these parts, that is, the soldering process on the substrate is not performed well.

For example, when connecting a jumper wire to a terminal on such a board, checking the continuity of a circuit pattern on the board, or cutting off continuity with a dummy pattern for testing, etc., it is necessary to solder or use a semicircular This makes it extremely difficult to remove the chips and perform the series of soldering processes that are conventionally performed on boards.

Measures to be taken when performing soldering processing that is rejected include supplying the necessary amount of heat using a soldering iron or heater tip with a large amount of heat, or using a conductor round (3) on the metal substrate (3) to be soldered as shown in Fig. 1) A through hole (2) for heat shielding is drilled in the peripheral area to thermally isolate the round (1) which is the soldering part, but the supply of a large amount of heat is achieved by high-density packaging. The latter method is unfavorable from the viewpoint of thermal effects on other elements and workability.The latter method requires through-holes in the board, which reduces component mounting density and reduces the degree of freedom in circuit design when arranging circuit patterns. inhibit.

[Object of the Invention] It is an object of the present invention to propose a method for successfully performing solder processing on a metal base substrate to form a circuit structure, regardless of such characteristics of the metal base substrate.

[Summary of the Invention] The circuit configuration method of the present invention provides a soldering part related to the circuit configuration on a component surface that does not face the substrate surface of a leadless component mounted on a metal base substrate, and the metal base is Soldering is performed on the separated parts.

[Embodiments of the invention] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 shows a metal substrate device showing an embodiment of the present invention, in which (40) is the aforementioned metal base substrate whose surface is insulated, and (12) is the surface of the substrate (10). A conductive circuit is formed in a predetermined pattern shape, and a solder resist is applied on the pattern, leaving a portion to be soldered to an electrode or conductor of a leadless component (chip component), which will be described later.

Leadless components are mounted on the board (10) by an automatic mounting machine, and the components and conductive circuits are soldered by reflow soldering.

The leadless components mounted in the same figure are circuit elements such as resistors and capacitors that have conductors (16) on both longitudinal sides of a rectangular parallelepiped insulator (14) such as ceramic in Figure 6. TYPEL constituting the , and the insulator shown in Figure 4 (
TYPE 2 in which a conductor (2o) is formed by delaying both longitudinal sides along with some surfaces of 18), and forming a conductor (24) on the insulator (22) shown in Fig. 6 by delaying the conductor (24) to one plane above both longitudinal sides. TYPE 3, an insulator (28) shown in Fig. 7, which constitutes a pair of coupling terminals (26) which can be brought close to each other due to the presence of slits (26) but are not substantially short-circuited on both side surfaces. A plurality of conductors (30) are provided in parallel extending from the side surface to the main surface, and a discarded conductor (30) is provided in the longitudinal direction on the surface opposite to the main surface in order to obtain a positive effect on the soldering of the component during reflow. There is a TYPE 4 leadless component with (32) added, and the above conductor is formed by electroless plating on a similar insulator such as ceramic, and both can be soldered to the conductor. and
In addition, such parts are designed to have approximately the same shape so that the number of types of dress parts can be reduced and they can be automatically mounted.

The leadless components mentioned above are shown in FIG. 3 using the numbers (19), (15), (23), and (29) assigned respectively in FIGS. Among these, those with a conductor on the main surface of the insulator are mounted without facing the board, and the component (29) is mounted with a conductor (
32) is mounted so as to face the board surface.

Also, leadless parts (19), (15), (23), (2
As for 9), it may be mounted across other circuit patterns, or it may be mounted across the circuit as a so-called jumper chip, which is commonly used in high frequency circuits for noise countermeasures. The structure is constructed without the need for the conductors of the parts to go around to a large extent.

Also, parts (l9) and (2) are mounted corresponding to the predetermined round positions in correspondence with circuit '#1 (12) on the board.
The portion 9) is located at a so-called terminal output portion of the board or a relay terminal portion intended for electrical connection with another board.

In this example, the sterilization leadless components are soldered by beam flow, so the conductors on the bottom and side surfaces of each component are soldered to the conductor circuit (12) on the board, and the components (19), (23)
, (29), among the portions led out to the main surface side, that is, not facing the metal substrate surface, no solder is attached to the conductor portion located on the top surface of the component.

Next, after the bulk soldering of the sterilization mount components is completed, the circuit on the metal base board (10) is soldered in a predetermined pattern.
Or conduct a continuity check of the element, but it is not possible to check the continuity of the element (
23), which are electrically connected to each other by solder (36) via a pair of connecting terminals (25) provided on the main surface of the connecting terminal (23), and then the two terminals are connected.

The circuit is closed when the coupling terminal is not connected, and the circuit is closed by short-circuiting with a check solder or the like, which is a well-known technique such as Japanese Utility Model Publication No. 55-47076, so a detailed explanation will be omitted.

However, as mentioned above, these soldering processes could not be carried out easily on metal substrates in the past, but in this example, the soldering process is on the leadless component (23), and the metal base is not heated. on the coupling terminal (25) separated from each other;
As shown in FIG. 2, the solder (38) can be easily attached with a small amount of heat, and the workability of the circuit structure is good.

Further, although the soldering process in the embodiment is to adhere solder, it may also be a circuit configuration process in which a pre-prepared solder mold is removed and a predetermined pattern is divided. This is a matter that can be changed at any time depending on the purpose of the configuration.

Next, components (19) and (29) are subjected to circuit configuration work for electrically connecting them to other boards, for example, by soldering connectors such as jumper wires.

At this time as well, as shown in Fig. 1, work with the soldering iron (42) is performed on the conductive surface of the leadless component (19) to be connected to the circuit pattern with solder (40), which is formed on the surface of the component that does not face the board. The jumper (44) is soldered (46) without being affected by the metal base.

In addition, even if the component (29) has multiple terminals, the heat effect on other mounted components is reduced and good soldering is achieved, and in this case as well, the soldering process is thermally separated from the base. This is done in the vicinity of the top surface of the extended conductor (30), which is the extended portion of the conductor (30).

Furthermore, the shape and circuit configuration of the leadless components to be soldered are not limited to this example, and can be changed in various ways, and may be placed on the element. Any position that is not affected by thermal diffusion of the substrate is sufficient.

Next, another example of a leadless component to be soldered will be described.

Figure 8 shows leadless parts (48
), and the insulating main body (50) is made of heat-resistant resin, while the electrically conductive and solderable metal (52)
) is inserted into an insert or a pre-prepared hole on the main body side, and is integrated with the main body as a leadless component.

The main body resin is not particularly intended for circuit configuration, but is shaped for the purpose of automatic installation along with the rectangular parallelepiped shape of the main body.
The metal (52) has its metal surface exposed on the main surface of the main body (50) and a surface located on the opposite side of the main surface.
The ends (54) of the metal (6) are both located at the end of the main body.
2) has a bent shape, and electrical connections on the circuit are made by the metal. The rejected component (48) can also be used as a jumper chip by soldering its end (54) to the board round together with other mixed components, but the exposed metal part that does not face the board in the mounted state can be used as the soldering surface, for example. It can be used as a similar terminal outlet.

In addition, if thermal isolation from the base is insufficient due to the shape and characteristics of the metal (52), as shown in Figure 9, a through hole for heat shielding (
58) may be used, and the heat shielding measure for the core metal may be a notch or the like.

[Effects of the Invention] As described above, according to the circuit configuration method of the present invention, the component surface of the leadless component to be mounted is effectively utilized to achieve thermal isolation from the metal base substrate, and it is possible to thermally isolate the leadless component from the metal base substrate. Or,
It facilitates soldering without applying heat shielding measures to the board itself, does not impede high-density mounting, and allows soldering to be performed with minimal thermal effects on components, making it practical. It's a blind move.

Also, since automatic mounting is possible, mass production is good.

[Brief explanation of the drawing]

Figures 1 to 91! I is a diagram explaining one embodiment of the present invention,
Figure 2 is a perspective view showing soldering process, Figure 3 is a perspective view of a metal base board device, Figures 4 to 9 are perspective views of leadless components, and Figure 1O is a conventional metal base FIG. 3 is a perspective view of a substrate. Explanation of the code (!0) is a metal base board. (15), (19), (23), (29), and (48) are leadless parts. (16), (20), (24), and (30) are conductors. Patent applicant Aiwa Co., Ltd. Figure N1 Figure M2 Figure 4 Figure 7 Figure 9

Claims (1)

[Claims] A method for configuring a circuit, comprising providing a solder attachment portion on a surface of a leadless component mounted on a metal base substrate that does not face the substrate, and performing a soldering process on the surface.