JPH0727649Y2 - Printed wiring board with resistor mounted on heat dissipation board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a printed wiring board provided with a heating resistor as a circuit component. In particular, it is excellent when applied to a hybrid integrated circuit.

[Conventional technology]

A conventional example will be described with reference to FIGS. 4 and 5. FIG. 4 is an explanatory view of a conventional example, and FIG. 5 is a sectional view taken along the line AA ′ shown in FIG. In the figure, a printed wiring board 21 is, for example, a substrate such as alumina having a good insulating property and a good heat dissipation property, and a wiring pattern 22 is formed thereon. The thick film resistor 23 and the circuit component 24 are formed on the printed wiring board 21 and are connected by the wiring pattern 22 to form a circuit.

The surface of the printed wiring board 21 is covered with a coating material 25, for example, a resin such as glass having good heat dissipation characteristics and insulating properties.

When power is supplied to the circuit formed on such a printed wiring board 21, the resistor 23 generates heat and affects the characteristics of the circuit and its vicinity.

[Problems to be solved by the device]

In recent years, the printed wiring board 21 has been miniaturized, and in particular, the circuit components on the hybrid integrated circuit have been miniaturized together with the integrated circuit (the integrated circuit referred to in the present specification includes all integrated circuits such as IC and LSI hereinafter). It is in.

In particular, when the resistor 23 is miniaturized, the resistance per area increases, and the heat generation also increases when a large amount of power is applied. At this time, the heat generated by the resistor 23 may temporarily change the resistance value greatly.

In addition, the long-term heat generation of the resistor 23 changes the resistance value by deteriorating the resistor 23. Therefore, there is a limit to miniaturization of the resistor 23 that requires a large amount of power.

The present invention is for solving the above problems,
An object of the present invention is to provide a printed wiring board provided with a resistor that exhibits good heat dissipation even when a large amount of power is applied to the resistor and that always exhibits an accurate resistance value.

[Means for Solving the Problems]

In order to achieve the above object, a printed wiring board having a resistor attached to a heat dissipation board of the present invention has a heating resistor as a circuit component, and has the same length as at least one width of the printed wiring board. Forming a space between the surface of the printed wiring board and the resistor, the resistor having a resistive film continuously formed on at least one surface of the heat dissipation substrate, and connecting terminals of the resistor and the printed wiring. It is composed of a clip-shaped resistor support metal fitting that electrically connects the external connection terminal of the plate.

[Action]

The applicant of the present invention has focused on using the upper space of the printed wiring board to attach only the heating resistor to the external connection terminals of the printed wiring board separately from other circuit components. Further, the present applicant has considered using a resistor in which a resistance film is continuously formed on at least one surface of a heat dissipation substrate having a length equal to the width of at least one of the printed wiring boards.

That is, according to the configuration of the present invention, the heat dissipation substrate having the resistance film continuously formed can be separated from the printed wiring board to have a sufficient size, so that the heat dissipation from the heat dissipation substrate is improved and the resistor There is no change in characteristics due to its own heat.

Further, since the heat dissipation substrate having the resistance film formed continuously can be made as large as one width of the printed wiring board, the surface area of the resistor can be made large and arbitrary. Therefore, the resistor of the present invention can obtain high resistance with a material having a low resistance value per unit area.
The accuracy of the resistance value can be improved, and variations during manufacturing can be eliminated.

Furthermore, since the resistor has the same width as at least one side of the printed wiring board, the clip-shaped support metal fitting can electrically connect the joining terminal of the resistor and the external connection terminal of the printed wiring board.

〔Example〕

FIG. 1 is a schematic explanatory view of a printed wiring board provided with a resistor according to the present invention, FIG. 2 is a sectional view of a resistor according to the present invention, and FIG. 3 is an explanatory view of a resistor support metal fitting according to the present invention. In the figure, a printed wiring board 1 is made of an alumina substrate or the like, and a wiring pattern 2 is formed by a known printing technique. Then, on the wiring pattern 2, an integrated circuit (not shown) and other circuit components are placed. In particular, among the circuit components, only those with low power load that generate less heat are attached. The resistor 4 includes a heat dissipation substrate 5, a resistor 6 formed on the substrate 5, a joint terminal 7, and a covering material 8 that covers the resistor 6. The heat dissipation board 5 is
For example, the resistor 6 made of an aluminum nitride substrate and formed on at least one side surface thereof has a high power load and can be obtained by a well-known thick film forming technique. The covering material 8 covering the resistor 6 is made of, for example, a glass material having good heat dissipation and insulating properties. Then, this glass material is melted by heating, and at the same time, the solvent in the glass is removed. The resistor support metal fitting 9 is made of, for example, a good electric conductor such as copper or aluminum, and has upper and lower terminal connecting portions 10 and 11.
Is equipped with. Upper and lower terminal connection parts 10 and 11 shown in FIG.
Has a clip shape, and the joining terminal 7 of the resistor 4 is fitted to the upper terminal connecting portion 10 and the terminal portion (not shown) of the printed wiring board 1 is fitted to the lower terminal connecting portion 11.

Then, for example, the printed wiring board 1 and the resistor 4 and the resistor support metal fitting 9 are fixed through a solder bath.

Although the embodiment of the present invention has been described in detail above, the present invention is not limited to the above embodiment. Various design changes can be made without departing from the present invention described in the claims for utility model registration.

For example, the materials of the substrate of the printed wiring board and the heat dissipation substrate of the resistor can be changed as needed. In particular, if all the resistors that generate heat can be formed above the printed wiring board, the substrate of the printed wiring board does not necessarily have to be an alumina substrate, but a cheaper substrate may be used.

Although two resistors are shown in FIG. 1, one resistor may be provided on the entire surface of the heat dissipation board, or several resistors may be provided.

Since the surface area of the resistor at this time can be made large and arbitrary, high resistance can be formed with a material having a low resistance value per unit area. Therefore, the value of the resistor of the present invention does not vary, and a highly accurate resistor can be obtained.

Furthermore, the resistor support metal fitting may not have a clip shape, but may have a U-shaped cross section as a whole, and the distance between the support portions can be set arbitrarily.

[Effect of device]

According to the present invention, the resistor formed of the resistance film continuously formed on at least one surface of the heat dissipation substrate having the same length as the width of at least one of the printed wiring boards has a space above the printed wiring board. Since it is attached by using it, it has a large area and can be arbitrarily taken.

According to the present invention, since a material having a low resistance value per unit area can be formed to have a high resistance, not only a resistor whose characteristics do not change due to heat but also a highly accurate resistor that does not vary during manufacturing can be obtained. To be

According to the present invention, since the heat generated by the resistor is dissipated only from the heat dissipation board separate from other circuit components, there is no need to dissipate heat from the printed wiring board, so that an inexpensive printed wiring board can be used.

According to the present invention, since both the joint terminals of the resistor and the external connection terminal of the printed wiring board are electrically connected, a special support metal fitting for mounting the resistor on the printed wiring board is not required, A clip-shaped object used when the printed wiring boards are laminated and attached can be used.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of a printed wiring board provided with a resistor according to the present invention, FIG. 2 is a sectional view of a resistor according to the present invention, FIG. 3 is an explanatory view of a resistor support metal fitting according to the present invention, and FIG. FIG. 5 is a sectional view taken along the line AA ′ shown in FIG. 1 ...... Printed wiring board 2 ...... Wiring pattern 3 ...... External terminal 4 ...... Resistor 5 ...... Heat dissipation board 6 ...... Resistor 7 ...... Joining terminal 8 ...... Coating material 9 ...... Resistor support metal fitting 10 ...... Upper terminal connection 11 …… Lower terminal connection

Claims (1)

[Scope of utility model registration request] 1. A printed wiring board having a heating resistor as a circuit component, wherein a resistance film 6 is continuously formed on at least one surface of a heat dissipation substrate 5 having the same width as at least one width of the printed wiring board 1. A space is formed between the resistor 4 and the surface of the printed wiring board 1 and the resistor 4, and the two joint terminals 7 of the resistor 4 and the external connection terminals of the printed wiring board 1 are electrically connected to each other. A printed wiring board comprising: a clip-shaped resistor support fitting 9 to be connected.