JPH06164308A - Surface mount base for multistage cascade connection filter - Google Patents

Abstract

PURPOSE:To provide a surface mount base of a multistage cascade connection filter capable of easily surface mount at an accurate position by making a base for which plural pieces filter elements are mounted beforehand mountable to a printed board as it is. CONSTITUTION:The base 1 is the surface mount base for cascade connecting two MCF filter elements 3 and is formed by the insulation of plastic or the like. The base 1 is provided with through holes 5, 5 for which the hot terminals 4, 4 of the filter elements 3, 3 are inserted and fixed by soldering and the through holes 7, 7 for which earth terminals 6, 6 are inserted and fixed. A conductive pattern 10 is printed on the surface of the base so as to ground one of the through holes 5, 5 through an input pad 8 at the back surface of the base 1 and the pattern 9 of the side wall of the base. Also, the other one is connected to an output pad 12 at the rear surface of the base 1 similarly by the conductive pattern 11. Also, the other through hole 5, 5 is mounted between the filters 3, 3 at the surface of the base 1 so as to connect the lead terminal of an interstage capacitance C1 by the conductive pattern 13. Consequently, the plural filter elements can be integrated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface mounting base used when surface-mounting a plurality of filter elements to be cascade-connected on a printed circuit board.

[0002]

2. Description of the Related Art Conventionally, when a single filter element cannot provide sufficient filter characteristics, it is generally practiced to connect a plurality of filter elements in cascade. If the MCF filter element most widely used today is used for the multi-stage cascade connection, as shown in FIG. 2, a capacitor C1 for inter-stage impedance matching is connected in parallel between one terminals of the MCF filter elements 3 and 3, as shown in FIG. Capacitors C2 and C3 for terminating impedance matching are respectively connected in parallel between the other terminals of the MCF filter elements 3 and 3 and the filter input / output terminal, and resistors R2 and R3 are provided.
It is common to insert each of these in series, but it is also possible to replace the capacitors C1 to C3 with the inductances L1 to L3. By the way, in order to mount these plural filter elements on the printed board, it is necessary to insert the lead portions extending from the filter elements into the through holes of the printed board one by one and solder them, but this is very troublesome. Was there. Therefore, the filter element was laid sideways and surface-mounted with the rod-shaped leads bent, but the filter element sealed in a metal can was placed parallel to the printed board and It was very difficult to mount a plurality of circuit patterns on the circuit pattern at the correct position.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to eliminate the drawbacks of individually mounting the conventional filter elements to be cascade-connected on the printed board as described above, and can easily and accurately position the filter elements. It is intended to provide a surface mount base for a multi-stage cascade connection filter that can be surface mounted.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above object, a surface mount base of a multistage cascade connection filter according to the present invention is made of insulating plastic or ceramic, and filter elements are connected in series on a filter element mounting surface of the base. The wiring pattern required for connection is printed on the surface facing the printed board with a pad for connecting with the circuit pattern of the printed board, and the connection pattern between the wiring pattern and the pad is printed on the side surface of the mounting table. At the same time, a lead portion extending from the filter element is inserted and fixed, and a through hole connected to the wiring pattern is provided.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the embodiments shown in the drawings.

1 (a), 1 (b) and 1 (c) are a plan view, a sectional view and a rear view, respectively, showing an embodiment of a surface mount base of a two-stage cascade connection filter according to the present invention. In the figure, reference numeral 1 is a surface mount base for cascade connection of two MCF filter elements according to the present invention, which is made of insulating plastic or ceramic, and is mounted on the base 1 by M.
The through-holes 5, 5 to which the hot terminals 4, 4, ... Of the CF filter elements 3, 3 are to be inserted and fixed by soldering ...
.. Similarly, through holes 7, 7 into which the ground terminals 6, 6 are to be inserted and fixed are provided, and the through holes 5, 5, ...
One is to connect the input pad 8 on the back surface of the base 1 and the pattern 9 on the side wall of the base 1 to the conductor pattern 10 on the surface of the base.
Is printed, and the other one is similarly connected to the output pad 12 on the back surface of the stand by the conductor pattern 11. Further, the other two through holes 5 and 5 are directly connected to each other by the conductor pattern 13, and the C1 is connected to the MCF filter element 3 on the surface of the base 1 so as to connect one lead terminal of the inter-stage capacitance C1 to the middle thereof. Three
To be implemented between. Further, the other lead terminal of the interstage capacitance C1 is connected to one of the through holes 7 and 7 and the conductor pattern 14.
, And the conductor pattern 14 is also connected to the ground pads 15, 15, ... On the back surface of the stand via the side wall of the stand 1. On the other hand, the other one of the through holes 7 and 7 is also similarly connected from the conductor pattern 16 on the surface of the base 1 via the side wall of the base 1 to the other ground pads 17, 17 ,.
.. are connected to.

By the way, the MCF filter elements 3, 3
Is generally enclosed in a metal can, and its bottom surface is also a metal surface except in special cases. Therefore, when the general MCF filter element as described above is mounted on the base 1 according to the present invention, a short circuit may occur via the conductor pattern printed on the surface of the base 1. To prevent this, the stand 1
The insulating film 2 may be applied or printed on the entire surface.

The embodiment in which only the filter element and the inter-stage impedance matching element (capacitor in this case) are mounted as a stand for mounting a plurality of filter elements in cascade connection and surface mounting is described above. The invention is not limited to this, and the termination impedance matching element shown in FIG. 2 can also be mounted if the space of the stand allows, or all the impedance matching elements as described above are provided on the printed board side. It can also be implemented without any special explanation. An operator inserts the lead terminals 5 and 6 extending from the plurality of filter elements 3 and 3 into the through holes 6 and 7 of the table according to the present invention, and solders the filter elements 3 and 3 from the back surface side of the table. The mounted base 1 may be surface-mounted on the printed board as it is.

[0009]

Since the present invention is configured as described above, an operator can mount a plurality of filter elements on the surface mounting table according to the present invention in advance and mount the table as it is on the printed circuit board. Since it is good, not only the work of multi-stage cascade connection of a plurality of filter elements can be facilitated, but also the filter of multi-stage cascade connection can be easily mounted at an accurate position on the printed board. It has a remarkable effect in reducing the manufacturing cost of the circuit including the circuit.

[0010]

[Brief description of drawings]

FIG. 1A is a plan view showing an embodiment of a surface mount base of a multistage cascade connection filter according to the present invention. (B) is sectional drawing which shows one Example of the surface mounting stand of the multistage cascade connection filter which concerns on this invention. (C) is a rear view showing an embodiment of a surface mount base of the multistage cascade connection filter according to the present invention.

FIG. 2 is a circuit configuration diagram of a multistage cascade connection filter.

[Explanation of symbols]

 1 ... Stand 2 ... Insulating film 3 ... Filter element 4 ... Hot terminal 5, 7 ... Through hole 6 ... Ground terminal 8 ... Input pad 9 ... Pattern 10, 11, 13, 14, 16 ... Conductor pattern 12 ... Output pad 15, 17 ... Ground pad

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[Procedure amendment]

[Submission date] November 22, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Fig. 2]

[Figure 1]

Claims (3)

[Claims] 1. A table used to integrate a plurality of filter elements sealed in individual packages in a cascade connection and surface-mounted on a printed circuit board, wherein the filter elements of the table are integrated. The mounting surface has a wiring pattern for connecting the mounted filter elements in a dependent manner, the surface facing the printed board has a pad for connecting with the circuit pattern of the printed board, and the wiring pattern and the pad are provided. A plurality of filter elements are preliminarily provided by printing a connecting pattern on the side surface of the table, inserting and fixing lead portions extending from the filter element in appropriate places of the table, and providing through holes for connecting to the wiring pattern. A surface mount base for a multistage cascade connection filter, wherein the mounted base can be mounted on a printed board as it is. 2. The wiring pattern provided on the filter element mounting surface and the pad provided on the surface facing the printed board are connected by a through hole or a via hole penetrating the base. Surface mount base for the described multi-stage cascade connection filter. 3. A part or all of the elements required for impedance matching between the filter element stages cascade-connected to the filter element mounting surface and cascade-connected filter termination impedances are mounted. Surface mount base for multi-stage cascade connection filter of.