JP2793824B2 - Electronic circuit board - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic circuit board, and more particularly, to a surface mount component mounted on a surface of the electronic circuit board. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic circuit board in which electromagnetic wave noise is shielded and interference between signal lines provided therein is suppressed.

[Prior Art] With the recent development of electronic circuit technology, the degree of integration of electronic components such as so-called semiconductor elements has been considerably increased. For example, various electronic devices are mounted on automobiles and various industrial devices, and the speed of operation of the electronic components is also increasing. For this reason, in the electronic equipment installed in the industrial equipment or the like, from the viewpoint of safety, it is required to ensure the shield so as not to be affected by electromagnetic noise outside the equipment. .
Also, for various digital and analog circuits,
With the development of microcomputer technology and sensor technology, higher-speed operation has been made possible, but these high-speed signal lines are particularly susceptible to interference from other electronic circuits, so that digital lines are also suitable. It is necessary to prevent interference with other electronic circuits, mutual interference between circuit patterns, and the like by performing a proper shield or the like.

FIG. 3 is a cross-sectional illustration of a conventional electronic circuit board of this type. In FIG. 3, an insulating substrate (11)
The first substrate (12) on the upper surface and the second substrate (13) on the lower surface
Thus, the predetermined electronic circuit board (50) is configured as a so-called multilayer printed wiring board.

A first inner layer conductor network (16) having a desired pattern is set between the insulating substrate (11) and the first substrate (12), and the insulating substrate (11) and the second substrate ( 13), a second inner conductor network (1) having a desired pattern.
7) is set. And this electronic circuit board (5
In the right place of (0), a first through hole (18) for conduction between the conductor networks in each layer, and in addition to such a conduction function, a conductor pin (25) to be described later is inserted. A second through hole (19) is provided. A first outer layer conductor (14) is provided on the upper surface of the first substrate (12).
A second outer layer conductor (15) is provided on the lower surface of the second substrate (13). The various surface mounting components (21) are fixed in place on the upper surface of the first substrate (12) by the first solder portion (22), and the cap (23) is also fixed to the first by the second solder portion (24). It is fixed at a suitable position on the upper surface of the substrate (12) and functions to protect the surface mounting component (21). Furthermore,
When the pins are connected, the conductor pins (25) having the flange-shaped locking portions (26) are moved from the lower surface of the second substrate (13) to the second positions.
It is inserted through the through hole (19) and is fixed by the third solder portion (27).

Here, the first outer layer conductor (14) and the second outer layer conductor (1)
5) is the upper surface of the first substrate (12) and the second
It is provided so as to almost cover the lower surface of the board (13), and therefore, between various electronic circuits provided outside and various electronic circuits provided inside the electronic circuit board (50). Is prevented from occurring.

In addition, noise generated by interference in a signal line is generally called crosstalk, and is caused by the influence of the coupling capacitance of the signal line. And
In order to prevent the occurrence of such crosstalk, a suitable effect is produced by interposing a low-dielectric substance between the signal lines or reducing the distance between the signal line and the ground plane. However, in the above-described conventional example, the thickness and the dielectric constant of the substrate constituting the printed wiring board cannot be controlled, and therefore, the coupling capacitance becomes large, so that signal interference easily occurs. As a result, the operational reliability of the equipment used may be reduced.

[Problems to be Solved by the Invention] According to the conventional electronic circuit board having the above-described configuration and operation, the thickness and the dielectric constant of the board constituting the printed wiring board cannot be controlled. There has been a problem in that conventional electromagnetic circuit boards on which electronic components are mounted have unsatisfactory electromagnetic shielding measures against external noise and internal noise.

The present invention has been made in order to solve the problems in the above conventional example, and the object thereof is to:
An object of the present invention is to provide an electronic circuit board for a surface mount component, which has a simple configuration, can sufficiently utilize and develop the conventional technology, and is provided with a required electromagnetic shield.

[Means for Solving the Problems] An electronic circuit board according to the present invention comprises a multi-layer board having a surface mount component mounted on a front surface thereof and a conductor pin connected to another substrate on a back surface thereof. An electronic circuit board, wherein the multilayer substrate has a large thickness and an internal substrate made of a material having a low dielectric constant, and an upper and lower external substrate made of a material having a small thickness and a high dielectric constant. An inner conductor circuit network is provided between the respective layers, and an outer conductor portion covering substantially the entire surface of the electronic circuit board is provided on the outer substrate, and the outer conductor portion is provided. Is an electronic circuit board which is a shield part and a power supply conductor of the electronic circuit board.

[Operation] According to the present invention, the outer layer conductors provided above and below the electronic circuit board not only function as shields but also function as power supply conductors.

Embodiment Next, the present invention will be described in detail based on an embodiment shown in the accompanying drawings.

FIG. 1 is an exemplary sectional view of an electronic circuit board according to an embodiment of the present invention. In FIG. 1, an insulating substrate (11
A), a predetermined electronic circuit board (50A) composed of a first substrate (12A) on the upper surface and a second substrate (13A) on the lower surface constitute a so-called multilayer printed wiring board.

Here, the thickness of the insulating substrate (11A) is equal to the thickness of the first substrate (12A).
And the thickness is considerably larger than the thickness of the second substrate (13A). Except for this difference, there is no structural difference between this embodiment and the aforementioned conventional example. It should be noted that a low dielectric constant triazine is used as the insulating substrate (11A), and a high dielectric constant epoxy is used as the first substrate (12A) and the second substrate (13A).

FIG. 2 is a perspective view showing a state where components for surface mounting are mounted on the above embodiment. In FIG. 2, the components constituting the surface-mounted component shield package (100) are various surface-mounted components provided in appropriate places other than the first outer layer conductor (14) on the upper surface of the electronic circuit board (50A). (21), a protective / sealing or shielding cap (23) provided to cover them, and an electronic circuit board (50A) for connection to a suitable motherboard (not shown)
A conductor pin (25) provided on the lower surface of the.

Embodiments of the present invention are obtained according to the steps exemplified below.

Process example 2.2mm thick glass-epoxy copper clad laminate (double-sided copper foil 7
0 μm), the first and second inner conductor networks (16) and (17) are formed by a normal subtractive method, and then the glass-polyimide prepreg (0.1 mm thick) (18 μm thick)
Are attached by a press method to form an electronic circuit board (50A). On this electronic circuit board (50A), a first through hole (18) for mutual conduction of the patterns of the first and second inner layer conductive circuit networks (16) and (17) is formed. Furthermore, in addition to the above-mentioned mutual continuity, power supply and conductor pins (2
A second through hole (19) for insertion of 5) is formed. After the first and second through holes (18) and (19) are formed, the first and second outer layer conductors (14) and (15) are formed. Thus, an electronic circuit board (50A) as a desired multilayer printed wiring board is obtained. Here, the first and second outer layer conductor portions (14) and (15) cover the entire surface of the electronic circuit board except for connection terminal portions for various electronic components and the like, and through hole installation portions. This can also be used as a power supply line. Then, in the second through hole (19) of the electronic circuit board (50A) as such a multilayer printed wiring board, a conductor pin (25) made of solder plated with Kovar is fixed by a high melting point solder dip method. As a result, the intended shield package (100) for surface mount components was obtained.

Thereafter, the surface mount component (21) was fixed to the corresponding element connection portion by soldering. Thus, a shield for a surface mount component having a high shielding effect and having a configuration surrounded by the first and second outer layer conductors (14) and (15) which are also power lines of the electronic circuit board (50A) as a multilayer printed wiring board.・ Package (100) was obtained.

[Effects of the Invention] As described above, the surface-mounted component shield package according to the present invention is characterized in that the surface-mounted component is mounted on the front side, and the conductor pin for connecting to another substrate is provided on the rear side. An electronic circuit board comprising a multi-layer substrate, wherein the multi-layer substrate has a large thickness and an internal substrate made of a material having a low dielectric constant, and a thin and high dielectric constant disposed above and below the internal substrate. An inner conductor circuit network is provided between each layer, and an outer conductor portion is provided on the outer substrate to cover substantially the entire surface of the electronic circuit board. And the outer layer conductor portion is a shield portion and a power supply conductor of the electronic circuit board. " Electronic times resolved A circuit board is provided.

According to the present invention, by using an electronic circuit board that can be electromagnetically shielded, it is possible to mix digital and analog circuits on the motherboard, and to suppress interference of signal lines inside the motherboard. To improve its reliability,
It is possible to easily realize a shield package for a surface mount component that operates effectively even in a poor environment where electromagnetic noise is large.

That is, in the electronic circuit board according to the present invention, since the conductor pattern for signal transmission has a configuration surrounded by an outer conductor which is a power supply line of the multilayer printed wiring board, the electronic circuit board is externally provided with the electronic circuit. It is possible to prevent electromagnetic wave noise from entering the board and to radiate electromagnetic wave noise from the electronic circuit board to the outside, and also to suppress interference between signal lines on the electronic circuit board. Therefore, when configuring a desired electronic circuit, the electronic circuit board according to the present invention accommodates a circuit that is sensitive to electromagnetic wave noise, or accommodates a high-frequency circuit that easily emits electromagnetic wave noise, and By configuring the circuit, local shielding or isolation can be realized, stabilizing the circuit operation, and greatly improving the reliability of the electronic circuit. Further, if most of the surface is covered with a metal foil as a conductor layer as in the present invention, its water resistance and weather resistance will be greatly improved, and furthermore, the inside By making the substrate a low dielectric constant material and increasing its thickness, and by making the external substrate a high dielectric constant material and reducing its thickness, the electromagnetic wave noise generated from the inner conductor circuit network flows to the outer conductor part. As a result, a synergistic effect of reducing the influence on other inner layer conductor networks and eliminating signal crosstalk between the inner layer conductor networks can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional illustration of an embodiment of the present invention, and FIG.
Perspective view of a state where the surface mounting component is mounted in the above embodiment,
FIG. 3 is a cross-sectional illustration of a conventional example. 11, 11A: center insulating substrate, 12, 12A: first insulating substrate, 13, 13
A: second insulating substrate, 50, 50A: electronic circuit board (multilayer printed wiring board), 14: first outer layer conductor (power supply line), 15: second
Outer layer conductor (power supply line), 16: 1st inner layer conductor network, 1
7: second inner layer conductor network, 18: first through hole, 19: second
Through hole, 21: surface mount component, 22: first solder part, 23:
Cap, 24: second solder portion, 25: conductor pin, 26: flange-shaped locking portion, 27: third solder portion, 100: shield package for surface mount components. In the drawings, the same reference numerals indicate the same or corresponding parts.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H05K 3 / 46,1 / 02 H05K 9/00

Claims (1)

(57) [Claims] 1. An electronic circuit board comprising a multilayer board, on which a surface mount component is mounted on a front side thereof and a conductor pin connected to another board on a rear side thereof, wherein the multilayer board comprises: An internal substrate made of a low dielectric constant material having a large thickness and an inner conductor circuit network formed on the front and back surfaces thereof, and a material having a small thickness and a high dielectric constant disposed on each of the upper and lower surfaces of the internal substrate. And an outer conductor portion that covers substantially the entire surface of the electronic circuit board is provided on the outer board, and the outer conductor portion is a shield of the electronic circuit board. An electronic circuit board comprising: a power supply conductor;