JPH08204307A - Structure for surface mounting type insulating board of electric circuit element - Google Patents

Abstract

PURPOSE: To cope with the two lead wires of a crystal resonator and three lead wires of a crystal filter by inserting the lead wires into lead wire inserting holes at the center of a metallic terminal block piece and using both ends of the metallic terminal block piece as terminals so as to make surface mounting possible. CONSTITUTION: In a long rectangular horizontal insulating board 28 put between a rectangular horizontal metallic base from which lead wires in the left part, central part, and right part of an electric circuit elements are protruded through small-diameter holes formed through the metallic base and a circuit board on which the electric circuit element is mounted, three metallic terminal block pieces 35 having the same size and buried in the insulating board 28 are insert- molded in parallel with each other at regular intervals. Then each electric circuit element is mounted on the surface of the circuit board in such a state that both ends of the terminal block pieces 35 are slightly protruded from the left and right sides of the insulating board 28 by passing each lead wire through a lead wire passing hole 31 at the center of each terminal block piece 35.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention prevents an electrical short circuit between a piezoelectric vibrator, a circuit board, etc., and other circuit elements adjacent to each other on the same circuit board, and enables automatic mounting in surface mounting. The present invention relates to a surface-mounted insulating plate structure for economical electric circuit elements.

[0002]

2. Description of the Related Art Piezoelectric vibrators such as crystal oscillators and crystal filters are widely used as reference signal sources and frequency filters in various electronic devices such as communication devices and digital control devices. By the way, in recent years, with the miniaturization of various electronic devices, each circuit element is densely arranged on a circuit board, and the arrangement work on the circuit board is automated by a robot. Incidentally, with the exception of exceptions, commonly used crystal resonators generally have the main dimensions shown in FIG. 5, and crystal filters often have the main dimensions shown in FIG. Manufacturers are competing in the technology to reduce the size and weight of the entire printed wiring as much as possible by soldering related members in a narrow space, and as a result, various problems have occurred. . Therefore, as a result of the higher density, the conductive paths of the circuit board and the circuit elements are narrowed. As a result, the conductive paths of the circuit board and the circuit elements easily come into contact with each other. An insulating material is interposed between the circuit board and the circuit board to prevent an electrical short circuit with the conductive path.

For example, as shown in the vertical cross-sectional view of FIG. 5, a crystal resonator element has conventionally been projected through a glass bush portion (hereinafter referred to as a glass portion) 2 of a metal base 1 having a horizontal oval shape. A supporter 4 is connected to each pair of lead wires 3, and both ends of the support wire 4 sandwich the outer peripheral portions of both ends extending from the electrode 6 of the crystal blank 5. The lower end of the metal cover 7 is sealed on the metal base 1 by resistance welding or the like to hermetically enclose the crystal piece 5. In the case of a surface mount device, a horizontal rectangular insulating plate 2 made of plastic or the like shown in FIG.
Insert the lead wires 3 into the pair of lead wire insertion holes 23 of No. 2 and flatten the lead wires 3 and 3 having a small-diameter circular cross-section protruding from the lower surface of the insulating plate 22 as shown by the hatching in FIG. The lead wire 3 is crushed into a cross section and bent along the vertical groove 24 on the lower surface of the insulating plate, and the crushed lead wire 3 of the crystal oscillator 25 is soldered to a conductive path (not shown) of the circuit board 26.
It is fixed by 7 etc.

[0004]

However, in this type of surface mounting type insulating plate 22, the insulating plate 22 is inserted after the lead wire 3 shown in FIG. 5 is inserted into the lead wire insertion hole 23.
It is necessary to crush the lead wire 3 protruding from the lower surface of the wire and bend it further.
Only two terminals can be taken, the terminal direction is also in the longitudinal direction, and the adhesion with the insulating plate 22 is poor and there is rattling.
As shown in FIG. 7, when placed on the circuit board 26, there is a risk of becoming unstable and eventually causing a failure. Further, there is a problem that a special jig and tool is required for the work, which takes a lot of trouble.

Further, in the conventional crystal filter, as shown in FIG. 8, a supporter 4 is connected to each of a pair of lead wires 3 projecting through a glass bush portion 2 of a horizontal oval metal base 1. The outer peripheral portions of both ends extending from the electrode 6 of the crystal piece 5 are sandwiched between the tips. A grounding lead wire 8 is attached to the metal base 1. Then, the metal cover 7 is sealed on the metal base 1 by resistance welding or the like, and the crystal piece 5
Is hermetically sealed. When this is mounted on a circuit board, for example, the lead wire 3 and the grounding lead wire 8 are inserted through the slit 10 in the longitudinal direction of the horizontal elliptic insulating plate 9 made of silicon rubber or the like shown in FIG. As shown in FIG. 10, the lead wire 3 and the grounding lead wire 8 of the crystal filter 11 are manually inserted into the lead wire insertion holes 13 of the circuit board 12 and fixedly arranged by the solder 14 or the like. This is intended to prevent an electrical short circuit with a conductive path (not shown).

However, since the crystal filter element of this type has three lead wires, the flat insulating plate 9 shown in FIG. 9 has the insulating plate 22 as shown in FIGS. 6 and 7. It is difficult to make the shape like the surface mount type used, and as shown in FIG. 10, it has to be directly inserted into the hole 13 of the circuit board 12 by hand, and other circuit elements can be automatically mounted by the surface mount type. Despite this, only the crystal filter is manually assembled, resulting in cost and quality problems.

The present invention has been proposed in view of the above circumstances, and can be commonly used for two lead wires of a crystal unit and three lead wires of a crystal filter, and is small in size. A lightweight, high-yield, high-performance and low-cost economical surface mount type insulation board structure with excellent workability, especially automatic mounting on a circuit board, cost performance, and quality improvement. The purpose is to provide.

[0008]

Therefore, the invention of claim 1 is the same as a metal base of a vertically long horizontal rectangle in which the lead wires of the left part, the center, and the right part of the electric circuit element respectively protrude through the small holes. In a vertically-long horizontal rectangular insulating plate inserted between a circuit board on which electric circuit elements are mounted, three metal terminal plate pieces of the same size embedded in the insulating plate are arranged in parallel at equal intervals. Insert-molded with synthetic resin, insert each lead wire into the lead wire insertion hole at the center of each metal terminal plate piece, and use both ends of each metal terminal plate piece as terminals respectively to the left and right of the insulating plate. It is characterized in that each of the electric circuit elements can be surface-mounted on the circuit board in a form slightly protruding from both sides.

According to a second aspect of the present invention, in the first aspect, the insulating plate is provided with projections for positioning the metal base at three positions out of the four corners of the upper surface, and at the remaining one position the same metal. A base for determining the direction of the base is formed and a dish-shaped surface is formed at the upper end opening of each lead wire insertion hole, or a low horizontal partition wall for preventing solder contact between each terminal plate piece on the lower surface of the insulating plate. In addition to providing a vertical groove for cleaning after mounting, draining water and blowing air, the insulating plate is an engineering plastic resin with excellent heat resistance, chemical corrosion resistance, mechanical strength and electrical characteristics. Or the insulating plate is made slightly larger in vertical dimension and lateral dimension than the external dimensions of the metal base of the electric circuit element.

According to a third aspect of the present invention, in the second aspect, the positioning projection of the metal base, the direction determining code portion, and the top end opening of each lead wire insertion hole are formed with a dish-shaped surface, and cleaning is performed after the mounting. , Provided with vertical recessed grooves for draining and air blowing, or provided with the insulating plate made of engineering plastic resin with vertical and horizontal dimensions slightly larger than those of its metal base, respectively. To do.

According to a fourth aspect of the present invention, in the third aspect, the vertical plate is provided with vertical grooves for cleaning, draining and air blowing, and the insulating plate formed of engineering plastic has vertical and horizontal dimensions. Each is equipped with the insulating plate formed to be slightly larger than that of the metal base.

[0012]

According to such a configuration, the following operation is performed. (1) The first and second lead wires of the crystal unit have a center line interval of 2p, and the first and second two lead wires are arranged in parallel on the same plane of the crystal filter. A circuit element having lead wires of the same diameter formed by defining the center line interval between the third two lead wires as 1p is arranged on a straight line with 1p of the common surface mount type insulating plate as a unit. The three lead wire insertion holes can be fitted and soldered. (2) Here, the three lead wire insertion holes are formed in the longitudinal groove formed in the lower surface of the surface mount type insulating plate, and the three lead wire insertion holes are provided between the first and second lead wire insertion holes. Since the space between the second and third lead wire insertion holes is partitioned by a horizontal partition slightly lower than the depth of the vertical groove, the central portion of the electrode plate piece embedded and molded in the surface mounting type insulating plate is divided. When soldering the lead wire to the center hole, there is no fear that the solders of the adjacent lead wire insertion holes will short-circuit, and cleaning, draining and air blowing after mounting can be effectively performed. (3) Since the countersunk holes that expand upward are machined in the upper end openings of the lead wire insertion holes, the lead wires can be fitted into the insertion holes very easily and protect the glass portion. (4) The surface-mounted insulating plate is formed by embedding a high-performance metal electrode plate piece in an engineering plastic resin such as PPS, and the left and right ends of the electrode plate piece are on both sides in the longitudinal direction of the surface-mounted insulating plate. It projects slightly outward from the edge. Therefore, heat resistance, chemical corrosion resistance, mechanical strength, and electrical characteristics when soldering are satisfactory, and both ends of the electrode plate piece protrude as a pair of left and right protruding electrode terminals. The number of points that can be soldered to is twice the number of leads, and connection with printed wiring is easy. (5) The vertical and horizontal dimensions of the surface mount type insulating board are made slightly larger than the vertical and horizontal dimensions of the metal base of the circuit element, and the metal base is positioned at three of the four corners of the surface mounting type insulating board. Since the projections are provided so as to project, and the remaining corner portions are formed with the obliquely cut surfaces as the code portions, the positioning and the orientation of the metal base can be performed quickly with high accuracy.

[0013]

Embodiments of the present invention will now be described with reference to the drawings.
1 is a perspective view showing the upper surface of the surface mount insulating plate as seen from above, FIG. 2 is a perspective view as seen from below to show the lower surface structure of FIG. 1, and FIG. 1 to 2 are partial vertical cross-sectional side views showing a state where the surface-mount insulating plate is attached to the surface mounting insulating plate, and FIG. 4 is a partial vertical side view showing a state where the surface mounting insulating plate of FIG. 3 is fixed to a circuit board.

First, one embodiment in which the present invention is applied to a crystal resonator will be described. The crystal resonator shown in FIG. 8 with the lead wires shown in the top perspective view of FIG. 1 and the bottom perspective view of FIG. A surface mount insulating plate (hereinafter referred to as "mounting insulating plate") is integrally assembled in the following procedure. The mounting insulating plate 28 shown in FIGS. 1 and 2 is made of PPS (polyphenylene sulfide) resin and N which are said to have the highest heat resistance among engineering plastics.
It consists of 42 alloy having i and Cr as the main components and good electrical conductivity. The shape of the upper surface is such that corner guides 29 are provided at three corners so as to prevent rattling between the metal base 1 (FIG. 8) and the mounting insulating plate 28, and also have directionality during automatic mounting. In order to avoid this, the remaining corner guide is omitted and the diagonal cut surface 30 is provided to prevent damage to the glass portion 2 of the metal base 1 and the lead wire 3.
Also, the upper end of the lead wire insertion hole 31 is chamfered in a dish shape to improve workability when the grounding lead wire 8 is inserted into the mounting insulating plate 28. Here, the inclined cut surface is provided at one of the four corners of the insulating plate, and instead of the marking which increases the cost, the insulating plate of the metal base can be visually observed by a simple structure or by a robot. Since it is possible to obtain the effect of the directional code portion that helps to quickly and surely determine the relative direction with respect to, it is particularly effective when assembling a circuit element having polarity on the common insulating plate. Further, this countersink facilitates insertion and soldering into the lead wire insertion hole formed in the metal base of the lead wire of the electric circuit element during assembly work,
Even if the lower end of the glass bush projects slightly from the lower end of the metal base, the glass bush is effectively prevented from being damaged. The pitch of the lead wire insertion holes 31 is equal to the lead pitch of the piezoelectric vibrator, and the lead wire insertion holes 3 having the same diameter are also provided in the center between the pitches so that three lead wires can be accommodated.
1 is open. Therefore, regardless of the number of lead wires, the structure can be used for both the crystal unit and the crystal filter, and the yield can be improved (Fig. 1).

As shown in FIG. 2, the shape of the lower surface is such that lateral partition walls 32 are provided between the electrodes so as to prevent contact of solder, and cleaning after mounting on the circuit board 26 and
A space for forming a vertical recessed groove 33 is provided between the bottom surface and the bottom surface so that the subsequent draining and air blowing can be performed perfectly. Further, each molded metal electrode plate 35 connected from each lead wire insertion hole 31 protrudes from the bottom surface in the left-right direction as a metal terminal 34, and two terminals at the left and right ends are provided for each lead wire. Have, total 6
It is a terminal (Figs. 1-2). Therefore, the surface mount insulating plate 28 for the piezoelectric vibrator is used for the crystal filter 11
After inserting the pair of lead wires 3 and the grounding lead wire 8 into the lead wire insertion hole 31 and fixing them to the back surface of the metal electrode plate 35 with solder 27 or the like, the surface mounting type crystal can be automatically mounted. It becomes a filter and a crystal unit (see Fig. 3). The surface-mounted crystal filter is automatically mounted on the circuit board 26 and then fixed by solder 27 by reflowing or the like (see FIG. 4). In this embodiment, since PPS resin is used as the material, it has a structure that can withstand mechanical external pressure during automatic mounting, high temperature in reflow after automatic mounting, and various chemicals. Further, the mounting insulating plate 28 is provided on the metal base 1 and the circuit board 2.
Not only to prevent the insulation from 6, but also to make the outer peripheral size slightly larger than the size of the metal base 1 of the crystal filter 11 in the lengthwise direction and the widthwise direction to prevent an electrical short circuit due to contact with other circuit elements. It also has the effect of preventing (Fig. 3).

In the above embodiments, the piezoelectric vibrator is described as a crystal filter, but it goes without saying that the structure of the present invention is also applied to piezoelectric vibrators and filter elements made of other crystals. Although resistance welding is used as the sealing means between the metal base and the metal cover, a metal base or a metal cover used for cold pressure welding may be used. In short, metal is used for a part of the base through which the lead wire penetrates, and it is applied to piezoelectric vibrators and filters that use a base in which an electrical short circuit with the conductive path of the circuit board may occur.

[0017]

INDUSTRIAL APPLICABILITY The present invention is excellent in heat resistance, insulation properties, corrosion resistance to chemical substances, mechanical strength, electrical characteristics, etc. by using PPS resin as an insulating material, In addition to insulating the circuit board, it also prevents electrical short-circuiting with other circuit elements, firmly fixing the circuit board with a total of 6 terminals, and eliminating rattling between the electric circuit element and the insulating plate. Automatic mounting can be enabled. As a result, the work efficiency of the mounting work on the circuit board is improved by automating the work of manually inserting the electric circuit element onto the circuit board, and the practical effect is extremely large.

In short, according to the first aspect of the invention, the left-side, the center, and the right-side lead wires of the electric circuit element are inserted into the small holes to project, and a vertically elongated horizontal rectangular metal base and the same electric circuit element are provided. In a vertically-long horizontal rectangular insulating plate inserted between a circuit board to be mounted, three metal terminal plate pieces of the same size embedded inside the insulating plate are inserted in parallel with a synthetic resin at equal intervals. Each lead wire is inserted into the lead wire insertion hole at the center of each metal terminal plate piece, and both ends of each metal terminal plate piece are used as terminals to slightly project from the left and right sides of the insulating plate. By enabling surface mounting of each of the above electrical circuit elements on the circuit board in this form, it is compatible with two lead wires of a crystal unit and three lead wires of a crystal filter. Can be small and light And the yield is good, workability,
In particular, the present invention is extremely useful industrially, since a high-performance and low-cost economical surface mount type insulating plate structure of an electric circuit element excellent in automatic mounting on a circuit board, cost performance, quality improvement, etc. is obtained. It is a thing.

According to a second aspect of the present invention, in the first aspect of the present invention, the insulating plate is provided with projections for positioning the metal base at three of four corners of the upper surface, and at the remaining one. The metal base is provided with a direction determining code portion and a dish-shaped surface is processed at the upper end opening of each lead wire insertion hole, or a lower surface of the insulating plate is provided to prevent solder contact between the terminal plate pieces. A horizontal partition is provided and a vertical groove is provided for cleaning, draining and air blowing after mounting, or the insulating plate is an engineering material excellent in heat resistance, chemical corrosion resistance, mechanical strength and electrical characteristics. It is made of plastic resin, or the insulating plate is made slightly larger in vertical dimension and horizontal dimension than the external dimensions of the metal base of the electric circuit element. Phil It is compatible with the three lead wires of a computer, has a small size and light weight, has a good yield, and has excellent workability, especially automatic mounting on a circuit board, cost performance, and quality improvement. INDUSTRIAL APPLICABILITY The present invention is extremely useful industrially because it provides a low-cost economical surface mounting type insulating plate structure for electric circuit elements.

According to the third aspect of the present invention, in the second aspect, the plate-like surface is formed at the upper end opening of the positioning protrusion and the direction determining code portion of the metal base and each lead wire insertion hole, and after mounting the same. By providing a vertical groove for cleaning, draining, and blowing air, or by providing the insulating plate made of engineering plastic resin with vertical and horizontal dimensions slightly larger than that of the metal base, respectively. It can be used for two lead wires of a crystal unit and three lead wires of a crystal filter in common, and it is small and lightweight, has a good yield, and has good workability, especially for a circuit board. The present invention is extremely industrially advantageous because it provides a high-performance and low-cost economical surface mount type insulating plate structure for electric circuit elements, which is excellent in automatic mounting, cost performance, quality improvement, and the like. Te is useful to investors.

According to a fourth aspect of the present invention, in the third aspect, the insulating plate is provided with a vertical groove for cleaning, draining, and air blowing, and the insulating plate formed of engineering plastic has a vertical dimension and a horizontal dimension. Since the size of the insulating plate is slightly larger than that of the metal base, it can be used for two lead wires of a crystal unit and three lead wires of a crystal filter. It is compact and lightweight, has a good yield, and has excellent workability, especially automatic mounting on a circuit board, cost performance, and quality improvement. The present invention is extremely useful industrially because it obtains a mold insulating plate structure.

[Brief description of drawings]

FIG. 1 is a perspective view showing a top surface structure of a surface mount insulating plate of an embodiment in which the present invention is applied to a piezoelectric vibrator element.

FIG. 2 is a perspective view showing a lower surface structure of the surface mount insulating plate of FIG.

FIG. 3 shows a conventional crystal filter element shown in FIG.
FIG. 3 is a partial vertical cross-sectional side view showing a state of being mounted on the surface mount insulating plate of FIG. 2.

FIG. 4 is a partial cross-sectional side view showing a state in which the surface mount insulating plate having the crystal filter of FIG. 3 mounted thereon is mounted on a circuit board.

FIG. 5 is a vertical cross-sectional view showing a conventional crystal resonator element.

FIG. 6 is a perspective view showing a lower surface of a surface-mounted insulating plate of the conventional crystal unit shown in FIG.

7 is a partial vertical cross-sectional side view showing a state in which the conventional crystal unit of FIG. 5 is mounted on a circuit board via the insulating plate of FIG.

FIG. 8 is a vertical sectional view showing a conventional crystal filter element.

9 is a perspective view showing an insulating plate of the conventional crystal filter element of FIG. 8. FIG.

FIG. 10 is a partial vertical cross-sectional view showing a state in which the insulating plate of FIG. 9 is attached to a conventional crystal filter and mounted on a circuit board.

[Explanation of symbols]

 1 Metal Base 2 Glass Bush Part 3 Lead Wire 4 Supporter 5 Crystal Piece 6 Electrode 7 Metal Cover 8 Lead Wire 9 Insulation Plate 10 Slit 11 Crystal Filter 12 Circuit Board 13 Hole 14 Solder 21 Metal Cover 22 Insulation Plate 23 Lead Wire Insertion Hole 24 Vertical recessed groove 25 Crystal oscillator 26 Circuit board 27 Solder 28 Crystal oscillator mounting insulating plate (mounting insulating plate) 29 Corner guide 30 Diagonal cut surface (sign part) 31 Lead wire insertion hole 32 Partition wall 33 Vertical passing space (vertical space) Through groove) 34 metal terminal 35 metal electrode plate piece

Claims (4)

[Claims] 1. A vertical-horizontal rectangular metal base in which lead wires of the left, center, and right portions of the electric circuit element are respectively inserted through the small holes and protrude, and a circuit board on which the electric circuit element is mounted. In the inserted vertically long horizontal rectangular insulating plate, three metal terminal plate pieces of the same size embedded in the insulating plate are insert-molded in parallel at equal intervals in parallel with each other by the synthetic resin. Each of the lead wires is inserted into the lead wire insertion hole in the central portion of the piece, and both ends of each of the metal terminal plate pieces are used as terminals to slightly project from the left and right sides of the insulating plate. A surface mounting type insulating plate structure for an electric circuit element, which enables surface mounting on the circuit board. 2. The insulating plate according to claim 1, wherein three protrusions for positioning the metal base are projected from three corners of the upper surface of the insulating plate, and the other one is used to orient the metal base. After forming the code part and processing a dish-shaped surface at the upper end opening of each lead wire insertion hole, or providing a low horizontal bulkhead on the lower surface of the insulating plate to prevent contact of solder between each terminal plate piece and after mounting Vertical recesses for cleaning, draining and blowing air, or heat resistance of the insulating plate,
Made of engineering plastic resin that has excellent chemical corrosion resistance, mechanical strength and electrical characteristics, or that the insulating plate has its vertical and horizontal dimensions slightly larger than the external dimensions of the metal base of the electric circuit element. Surface mount type insulating plate structure for electric circuit elements. 3. The plate according to claim 2, wherein a plate-like surface is formed on the positioning protrusion and the direction determining code part of the metal base and the upper end opening of each lead wire insertion hole, and cleaning, draining and air blowing after mounting are performed. Or an insulating plate made of an engineering plastic resin, the vertical dimension and the lateral dimension of which are slightly larger than those of the metal base, respectively. Surface mount type insulation board structure. 4. A vertical groove for cleaning, draining, and blowing air according to claim 3, wherein the insulating plate made of engineering plastic has a vertical dimension and a horizontal dimension, respectively. A surface mount type insulating plate structure for an electric circuit element, comprising the insulating plate formed to be slightly larger than that.