JPH0756908B2 - Electronic circuit device - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electronic circuit device in which an integrated circuit device (IC) is mounted on a mother substrate, and more specifically, measures against unnecessary radiation and noise that occur subsequently. Regarding

(B) Conventional technology Conventionally, in an electronic circuit device in which an IC is mounted on a mother board, undesired radiation or external noise may occur, which could not be predicted at the time of design. In such a case, an additional board 31 is used as shown in FIG. 6 as a method of temporarily dealing with the change without changing the mother board. An RC filter circuit, for example, is formed on the additional substrate 31, and is electrically connected to the lead 12 of the IC 11 (or the pad 14 of the mother substrate 13) using the wire 32.

(C) Problems to be Solved by the Invention In the conventional electronic circuit device described above, the additional substrate 31 and the IC 11 are provided.
There is a problem that the leads 12 and the like are connected to each other by soldering the wires 32 one by one, and it is troublesome and the reliability is lowered due to the breakage of the wires. More wire 32
There is also a problem that the line noise increases due to the fact that the line noise is distorted.

The present invention has been made in view of the above, and an object thereof is to provide a highly reliable electronic circuit device in which a substrate can be easily added.

(D) Means and Actions for Solving the Problems In order to solve the above problems, the electronic circuit device of the present invention is
A pad corresponding to the lead of the integrated circuit device to be mounted is provided on the front surface of the insertion board, the lead of the integrated circuit device is connected to this pad to mount the integrated circuit device, and a connection portion corresponding to the pad is provided on the back surface of the insertion board. An insertion circuit is provided on the insertion board, in which the corresponding pads and connection parts extend over the front and back of the insertion board and are connected by a wiring pattern with circuit elements, and mounting components are attached to the connection parts. The insertion board is mounted on the mother board by electrically connecting to the corresponding pads above.

In this electronic circuit device, an insertion board is added between the IC and the mother board, and the leads of the IC and the pads on the insertion board, and the mounted components and the pads on the mother board attached to the connection parts on the back surface of the insertion board. Since reflow soldering or conductive adhesive can be applied, automation is easy and labor is saved, and the risk of disconnection is reduced. Further, since it is not necessary to twist the wire as in the conventional case, it is easy to form the line noise less easily.

(E) Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

In this embodiment, the present invention is applied to a QFP (Quad Flat Package) IC.
This is applied to the mounting of 11, and an RC filter circuit is configured as an insertion circuit on the insertion board 1.

FIG. 1 is a vertical sectional view of an electronic circuit device according to this embodiment,
3 (a) and 3 (b) show the surface 1a of the insertion substrate 1,
It is a figure which shows the principal part of the back surface 1b. The insertion board 1 is made of, for example, ceramic, and has through holes 2, ...

Pads 3, ..., 3 are formed on the surface 1a of the insertion substrate in the same arrangement as the leads 12 of the IC 11. Also, from the front surface 1a to the back surface 1b
The wiring pattern 5 is formed through the through hole 2, and the connection portion 5a of the wiring pattern 5 is formed on the back surface 1b.
Are also arranged in the same arrangement as the corresponding leads 12 of IC11.

The pad 3 and the wiring pattern 5 are connected by the resistor 4 on the front surface 1a. The resistor 4 is formed by, for example, screen-printing a resistor paste and firing it, and its resistance value is adjusted by laser trimming. Of course, for all IC leads 12, resistor 4
It is not necessary to insert, and in the case of Fig. 3 (a), GND
The pad 3 _G for wiring and the wiring pattern 5 _G are directly connected.

A dielectric 6 is formed on the wiring pattern 5 on the back surface 1b of the insertion substrate. Also, the insulating film 7 is formed on the central portion of the back surface 1b.
Are formed. A GND pattern 8 is formed on the dielectric 6 and the insulating film 7. The GND pattern 8 through the through-holes 2 _G, is connected to the wiring pattern 5 _G. Further, the GND pattern 8 also has a connecting portion 8a,
An array is formed together with the connection portion 5a of the wiring pattern 5.
The dielectric 6 creates a capacitor (C) between the wiring pattern 5 and the GND pattern 8, and the resistor 4 constitutes an RC filter circuit. The insulating film 7 and the wiring pattern 5
This is to prevent a short circuit with the GND pattern 18.

Further, on the back surface 1b of the insertion board, the wiring pattern connecting portion 5a
Solder or conductive paste for square surface mount components
10 is mounted. As shown in FIG. 2, the square surface mount component 10 includes an aluminum ceramic substrate 10a, a front surface (conductive) pattern 10b, a rear surface (conductive) pattern 10, and a side surface electrode 1.
Formed 0d and 10e.

This square type surface mount component 10 is also a pad on the mother board 13.
Soldered to 14. Therefore, the IC lead 12 is electrically connected to the pad 14 on the mother board 13 along the path of the pad 3, the resistor 4, the wiring pattern 5, and the square surface mount component 10.

The square surface mount component 10 is used because the dielectric 6, the GND pattern 8 and the like are formed on the back surface 1b of the insertion board, and therefore the insertion board 1 needs to be mounted slightly floating with respect to the mother board 13. Is. A metal chip or the like can be used instead of the square surface mount component 1, and can be appropriately changed.

The through-hole 2 is applied to the insertion board 1
This is to obtain a space for forming the resistor 4 and the dielectric 6 above. For the IC lead 12 that does not require the RC filter, it is possible to form a side surface electrode on the side surface 1c of the insertion substrate 1 to electrically connect the pad 3 and the square surface mount component 10.

Further, it is also possible to form a dielectric on the front surface 1a of the insertion substrate and a resistor on the rear surface 1b, respectively.
It is also possible to form both a resistor and a dielectric on either one of the above.

FIGS. 4 (a) to 4 (d) are views for sequentially explaining the assembling process of the electronic circuit device of the embodiment. First, the insertion substrate 1 is turned over, and the conductive paste (or high melting point cream solder) 9a is placed on the connecting portions 5a and 8a by means such as printing [see FIG. 4 (a)]. Next, the square surface mount component 10 is mounted on the connecting portions 5a and 8a, and the conductive paste 9a is cured (or the high melting point cream solder is reflowed) [see FIG. 4 (b)].

Next, the insertion board 1 is returned to the original position, and the cream solder 9b is placed on the pad 3 by means of printing or the like [see FIG. 4 (c)].
Then mount IC11 and reflow to lead 12
To the pad 3.

Furthermore, cream solder 9c is placed on the pad 14 of the mother board 13.
Is printed, the insertion substrate 1 is mounted so that the square surface mount component 10 is located on the pad 14, and reflowing is performed to solder the square surface mount component 10 to the pad 14.

FIGS. 5A and 5B show an insertion board 21 according to a modified example. A wiring pattern 25 is formed on the insertion board 21 through the three holes 22 from the front surface 21a to the back surface 21b. On the front surface 21a, the ends of the wiring pattern 25 are pads 25b, and on the back surface 21b, the ends of the wiring pattern 25 are connections 25a.

On the surface 21a, the wiring pattern 25 is shielded so as to be sandwiched between the two ferrite layers 24a and 24b. As with the insertion board 1, the insertion board 21 also has the rectangular surface mount component 10 attached to the connection portion 25a, the IC lead 12 soldered to the pad portion 25b, and the IC 11 attached to the surface 21a.
The square surface mount component 10 is soldered to the pad 14 of the mother board 13.

(F) Effect of the Invention As described above, the electronic circuit device of the present invention is provided with the pad corresponding to the lead of the integrated circuit device to be mounted on the surface of the insertion substrate, and the lead of the integrated circuit device is connected to this pad. The integrated circuit device is mounted by mounting the connection circuit on the back surface of the insertion board, and the corresponding pads and connection sections extend over the front and back of the insertion board, and the insertion circuit is connected by the wiring pattern with the circuit elements. Formed on the insertion board,
The insertion board is mounted on the mother board by attaching the mounting parts to the connection part and electrically connecting the mounting parts to the corresponding pads on the mother board. It has the advantage of improving the quality. It also has the advantage that it can be made stronger against line noise.

In addition, since the insertion board is mounted on the mother board via mounting components, a space where a wiring pattern or circuit element (dielectric, resistor, etc.) can be formed between the rear surface of the insertion board and the mother board. Thus, the front and back of the insertion board can be effectively used.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an electronic circuit device according to an embodiment of the present invention, FIG. 2 is an enlarged vertical cross-sectional view of a rectangular surface mount component of the electronic circuit device, FIG. 3 (a) and FIG. FIG. 3 (b) is a view showing the main part of the front surface and the back surface of the insertion board of the electronic circuit device, FIG. 4 (a), FIG. 4 (b), FIG. 4 (c) and FIG. 4 respectively. (D) is a figure which respectively explains the assembly process of the same electronic circuit device, Drawing 5 (a) is a longitudinal section of an insertion board concerning a modification, and Drawing 5 (b) is the insertion board surface. FIG. 6 is an enlarged perspective view of an essential part of FIG. 6, and is a view for explaining a conventional electronic circuit device. 1.21: Insertion board, 3.14, 25b: Pad, 4: Resistor, 5
・ 25: Wiring pattern, 6: Dielectric, 8: GND pattern, 10: Square type surface mount component, 11: IC, 12: Lead, 13: Mother board, 24a
・ 24b: Ferrite layer.

Claims (1)

[Claims] 1. A pad corresponding to a lead of an integrated circuit device to be mounted is provided on the front surface of the insertion board, the lead of the integrated circuit device is connected to the pad to mount the integrated circuit device, and the pad is provided on the back surface of the insertion board. A corresponding connecting part is provided, and the corresponding pad and connecting part extend over the front and back of the insertion board and an insertion circuit connected by a wiring pattern provided with circuit elements is formed on the insertion board, and mounting parts are attached to the connection part. An electronic circuit device characterized in that an insertion board is mounted on a mother board by electrically connecting mounted components to corresponding pads on the mother board.