JPS62155525A - Hybrid integrated circuit - Google Patents

Abstract

PURPOSE:To improve heat-dissipating properties, to prevent the deterioration of characteristics due to heat and to enhance operating efficiency by forming a stepped section to the back of a wiring substrate and fitting input/output terminals onto the lower surface of the back. CONSTITUTION:Stepped sections where oppositely faced side edge sections 7 along long sides are each lowered and a central section 8 is heightened are shaped to the back of a wiring substrate 5. The height of the stepped section, the difference of the height of the side edge section 7 and the central section 8, is made the same as the thickness of input-output terminals mentioned below or higher than that. A plurality of conductor pads 9 for mounting the input- output terminals are formed respectively at regular intervals on the side edge sections 7 on the lower sides of the stepped sections, and the input/output terminals 10 are each fixed through silver soldering in parallel with the back of the wiring substrate 5, directing nose sections thereof outward to these conductor pads 9 for fitting the input/output terminals. The whole central section 8 of the back having a wide area is brought into contact with a surface to be loaded, thus resulting in an easy escape from the wide heating surface of heat generated in the hybrid integrated circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a flat package type hybrid integrated circuit.

[Technical Background of the Invention] In recent years, flat package type hybrid integrated circuits have been increasingly used in response to demands for smaller and lighter electronic devices, higher performance, and higher reliability.

Figures 3 and 4 show such a flat package type hybrid integrated circuit, in which a plurality of active and passive circuit elements (both not shown) are mounted on a multilayer wiring board 1. , these are all hermetically sealed with a metal cap 2. In addition, on the back side of the wiring board 1, conductor pads 3 for mounting a plurality of input/output terminals to which input/output signal wiring is connected are arranged in two rows at equal intervals. One input/output terminal 4 is connected to each conductor pad 3 in parallel to the back surface by silver soldering.

[Problems with the Background Art] However, in such a hybrid integrated circuit, conductor pads 3 for attaching input/output terminals are formed on the smooth, flat back surface of the wiring board 1, and input/output terminals 4 are fixed to these. Since the input/output terminals 4 protrude from the back surface of the wiring board 1 by the thickness thereof, when this hybrid integrated circuit is mounted on a motherboard etc., only the bottom surface of the input/output terminals 4 can be mounted. This resulted in most of the back surface of the wiring board 1 being lifted up. Therefore, in such a hybrid integrated circuit, it is difficult for heat to escape to the motherboard etc. during operation, and there is a problem that sufficient reliability in terms of characteristics cannot be obtained.

In addition, when manufacturing a hybrid integrated circuit or after a temperature test, the hybrid integrated circuit is placed on a metal plate with high thermal conductivity to dissipate heat and cool it, but in this case as well, the input/output terminals are in contact with the metal plate. 4, there was a problem in that heat dissipation was insufficient and the efficiency of cooling work, testing, etc. was extremely poor.

Metal cap 2 in the process of manufacturing a rough hybrid integrated circuit
The interior of the wiring board 1 is vacuum-suctioned, but since the input/output terminals protrude from the bottom surface when performing this work, the input/output terminals 4 protruding from the back surface are attached to the jig for fixing the wiring board 1. It was necessary to provide a part to allow the thickness to escape, and as a result, the jig had to have a special shape, which caused problems in that it required a lot of cost and man-hours to manufacture.

[Object of the Invention] The present invention has been made in order to solve these problems, and is a hybrid method that has a good heat dissipation effect from the back side of the wiring board, is highly reliable, and is efficient in manufacturing and testing. The purpose is to provide integrated circuits.

[Summary of the Invention] In other words, the hybrid integrated circuit of the present invention has a plurality of circuit elements mounted on the front surface of a wiring board, and a plurality of conductor pads for mounting input/output terminals on the back surface thereof. In a hybrid integrated circuit in which a plurality of input/output terminals are fixed to conductive pads parallel to the back surface, output terminal mounting is performed by providing a step on the back surface of the wiring board that is equal to or greater than the thickness of the input/output terminals, and By forming conductor pads for mounting the input/output terminals on the lower side of the step, the heat dissipation effect from the back side of the wiring board is improved, thereby improving reliability, and reducing work during manufacturing and testing. It also improves efficiency.

Note that when the hybrid integrated circuit of the present invention is mounted on a metal-based wiring board, such as a metal core wiring board, a board with circuit wiring on a β plate through a resin insulating layer, or a stainless steel wiring board, In particular, it has the effect of improving heat dissipation.

[Embodiments of the invention] The present invention will be described below with reference to embodiments shown in the drawings.

FIG. 1 and FIG. 2 are a front view and a perspective view, respectively, showing an embodiment of the hybrid integrated circuit of the present invention, as seen from the back side.

In these figures, reference numeral 5 indicates a multilayer wiring board made of, for example, ceramic, on which a conductive pattern is formed, and active circuit elements such as memory, resistors, and capacitors are placed at predetermined positions on the board. A plurality of passive circuit elements are mounted.

The entire surface on which these circuit elements are mounted is hermetically covered with a metal cap 6.

Further, the back surface of the wiring board 5 is provided with a step in which opposing edge portions 7 along the long sides are lower and the center portion 8 is higher. The height of this step, that is, the difference in height between the edge portion 7 and the center portion 8 is equal to or higher than the thickness of the input/output terminal described later.

Roughly on the lower edge 7 of this step, conductive pads 9 for mounting a plurality of input/output terminals are formed at equal intervals. An input/output legitimate child 10 is fixed to each of the wiring boards 5 by silver soldering, with the tip facing outward and parallel to the back surface of the wiring board 5.

In the hybrid integrated circuit of this embodiment, the input/output terminals 10 are attached to the edge part 7 which is lower than the center part 8 which occupies most of the back surface of the wiring board 5 by the height of the step. When an electronic circuit is constructed by mounting the hybrid integrated circuit on a motherboard, the large central part of the back surface will come into contact with the mounting surface, so the heat generated in this hybrid integrated circuit will be transferred to this large heat transfer surface. It is easy to escape from heat, and there is little risk that the characteristics of the hybrid integrated circuit will deteriorate due to heat.

Also, when cooling the hybrid integrated circuit by dissipating heat during manufacturing or testing, by placing the metal cap 6 on top of a metal plate with high thermal conductivity, the central part 8 on the back side of the wiring board 5 can be cooled. Heat can be rapidly dissipated from a wide heat transfer surface.

[Effects of the Invention] As explained above, in the hybrid integrated circuit of the present invention, a step is provided on the back surface of the wiring board, and input/output terminals are attached to the lower surface of the step. When mounted on other circuits, the heat generated during operation quickly escapes through the higher surface, which occupies most of the back surface of the wiring board, so there is little risk of property deterioration due to heat.

Furthermore, during heat dissipation cooling during manufacturing and testing, heat can be dissipated rapidly by simply placing it on a metal plate with high thermal conductivity, improving work efficiency.

Since there is no need for a specially shaped wiring board fixing jig during rough manufacturing, there is an advantage in that costs and man-hours are saved.

[Brief explanation of drawings]

Fig. 1 is a front view showing an embodiment of the hybrid integrated circuit of the present invention, Fig. 2 is a perspective view of the same as seen from the back side, and Fig. 3 is a front view showing a conventional flat package type hybrid integrated circuit. , FIG. 4 is a perspective view of the same as seen from the back side. 1.5...Wiring board 2.6...Metal cap 3.9...Conductor pad for mounting input/output terminals 4.
10... Input/output terminal applicant: Toshiba Corporation, agent, patent attorney, Sasu Suyama - Figure 1, Figure 2, Figure 40

Claims (2)

[Claims] (1) Multiple circuit elements are mounted on the front surface of the wiring board, and multiple conductor pads for attaching input/output terminals are formed on the back surface of the wiring board, and multiple input/outputs are mounted on these conductor pads for attaching input/output terminals. In a hybrid integrated circuit in which terminals are each fixed in parallel with the back surface, a step is provided on the back surface of the wiring board that is equal to or greater than the thickness of the input/output terminal, and the input/output terminal is mounted on the lower surface of the step. 1. A hybrid integrated circuit characterized by forming conductor pads for (2) The hybrid integrated circuit according to claim 1, wherein the wiring board is mounted on metal-based wiring or the like.