JPH0681141U - Surface mount crystal filter - Google Patents

Abstract

(57) [Abstract] [Purpose] At least two crystal filters should be combined so that they can be handled by a mounting machine and that their height is low. [Structure] Elements # 1 and # 2 whose input terminals 1, output terminals 3 and earth terminals 2 of a crystal filter housed in a container 4 serve as confidential terminals are inserted into a metal clamp 10 formed in a vertically long C-shape. Then, the terminals are connected to a wiring pattern formed on the multilayer substrate. [Effect] The upper surface of the metal clamp 10 can be adsorbed to the vacuum attachment / detachment device, and mounting on a printed circuit board becomes easy.

Description

[Detailed description of the device]

[0001]

[Industrial technical field]

 The present invention relates to a monolithic crystal filter, and more particularly to a small surface mount type 4-pole monolithic crystal filter.

[0002]

[Prior art]

 In recent years, electronic components used in mobile communication devices and the like have been required to be surface-mounted, and in particular have a height of 4 mm or less, and a crystal filter is no exception. The capacitance of a single element type monolithic crystal filter is the same as that of a general crystal oscillator, and only three hermetic terminals are used. That is, as shown in FIG. 4 (a), the crystal oscillator is housed in a can-type container 4, and the input terminal 1 and the output terminal 3 are pulled out from the lower part of the container 4 by the confidential terminal. ing.

The terminal 2 in the central portion indicates a ground terminal, and this ground terminal 2 is connected to a container 4 having a shield function. Such a crystal filter is shown as an equivalent circuit as shown in FIG. 4 (b). Especially, depending on the pass characteristics of the filter, two crystal filter elements as shown in FIG. 4 are combined as # 1 and # 2. It is generally used as a four-pole crystal filter by this combination, and a larger amount is used than a one-element crystal filter.

[0004]

[Problems to be solved by the device]

 However, as shown in FIG. 5, such a crystal filter does not currently have a height H of 4.5 mm or less when mounted on the IC substrate 5. Therefore, as shown in FIG. 6, it is considered that the two elements # 1 and # 2 are laid sideways so as to be stacked. In this case, the crystal filter is supplied to the IC substrate 5 by the component mounter. Becomes difficult.

Further, as shown in FIG. 7, when the two elements # 1 and # 2 are arranged on the substrate 7, the flange 4A of the container 4 becomes an obstacle and the element tilts. I have a problem with

[0006]

[Means for Solving the Problems]

 The present invention is a combination of two element monolithic crystal filters so that the height is 4 mm or less and the volume is 0.4 cc or less. In addition, the metal case of each element is inserted into a cylindrical metal clamp having a vertically long C-shaped cross section so that the upper ends of the metal cases face each other, and the airtightness is drawn from the external lead-out terminal of each element. The terminals are arranged at both ends to be integrally formed with the metal clamps, and the confidential terminals are bent into an L shape.

Further, the crystal filter is mounted on a multilayer printed circuit board, and a capacitor for inter-stage matching of each element is formed by patterning between the layers of the multilayer printed circuit board to integrally form a surface mount type crystal filter structure. It is what

[0008]

[Action]

 As described above, the present invention constructs a cylindrical metal clamp according to the shape of the two crystal filter containers, and inserts it so that the upper ends of the crystal filters abut against both ends of the metal clamp. By fixing the input and output terminals of the filter to the pudding and the substrate, the two elements are integrated, so that it can be handled as a mounted crystal filter.

[0009]

【Example】

 1A and 1B show an assembled side view of a two-element type crystal filter (four-pole filter) of the present invention and the assembled side view. Two crystal filter elements # 1 and # are shown. 2 and a metal clamp 10 formed so that the crystal filter container 4 is inserted therein is shown in a perspective view.

The metal clamp 10 is formed by processing a product name, model number, mark 10B, etc. on the surface, for example, brass or aluminum plate, and is formed into a cylindrical shape so that the inner surface has a vertically long C shape. Since the slits 10A are provided, when the crystal filters # 1 and # 2 are inserted from the direction shown by the arrow in the drawing, the upper end surface of the container 4 is inside the metal clamp 10 as shown in FIG. In opposition, the terminals of the crystal filter will be elastically fixed while being pulled out to both sides. Then, in this state, the printed board 20 may be fixed with an adhesive 20A, and the output terminals 1, 2, and 3 may be directly soldered to the wiring pattern.

However, in this state, the terminal is unstable until the crystal filter is mounted, and the terminal size may be distorted when the crystal filter is mounted. Therefore, in the present invention, it is preferable that the two-element crystal filters # 1 and # 2 fixed by the above-mentioned metal clamp 10 are fixed on a multi-layer substrate so that they can be handled by a mounting machine, as described below. .

FIG. 2 shows an example of a multi-layer substrate for mounting the two-element crystal filters # 1 and # 2 integrated by the metal clamp 10. Wiring patterns 11, 12, and 13 to which terminals 1, 2 and 3 of element # 1 are soldered, and wiring patterns 11 ′ to which terminals (1, 2, 3) of second element # 2 are soldered, 12 'and 13' are formed. It is preferable that one of the corners is cut off and the direction of the printed circuit board is determined by the cutout portion 20B.

The wiring pattern 13 serving as the output of the first element # 1 and the wiring pattern 13 ′ serving as the input of the second element # 2 are connected to each other, and the central portion thereof is formed on the lower surface of the substrate 20. The capacitor is formed so as to face the wiring pattern 14 and form a capacitor. That is, the wiring pattern 14 serving as the ground line on the lower surface serves as the ground electrode on the lower surface so that the area A and the area B of the wiring pattern sandwich the substrate 20 to form a capacitor. The connection terminals 15 and 15 connected to the wiring pattern of the mounting board are formed on both sides of the lower surface of the double-sided board 20, and the wiring patterns 11, 12 and 11 ′, 12 of the upper surface are connected. The crystal filter of the present invention can be handled in the same manner as a surface mountable chip component by being connected to the'through a through hole.

Another embodiment of the above-mentioned wiring pattern is shown in FIG. 3. This figure shows the wiring pattern of a four-layer board as a board on which the 4-pole crystal filter coupled by the metal clamp 10 is mounted. Indicates the part where the X points are connected by through holes. In this figure, (A), (B), (C), (D), and (E) are wiring patterns of the component surface, the inner layer 1 surface, the inner layer 2 surface, and the soldering surface of the four-layer board, and these are connected by the metal clamp 10. Fig. 2 is a top view sequentially showing the mounting of the two crystal filters described above. Among the recesses 1, 2, 3, 4, ... provided in the periphery of each substrate, 1, 3 ,, 5, 6, 8, 10 are ground terminals. Further, the concave portion 2 shows an input terminal portion of the crystal filter, and the concave portion 7 shows an output terminal portion thereof.

The connection electrodes formed in the recesses 4 and 9 can be used as terminal portions to which capacitors for impedance matching can be additionally connected between the crystal filters # 1 and # 2. Has been done.

[0016]

[Effect of device]

 As described above, the 4-pole monolithic crystal filter according to the present invention is integrated by providing a metal lamp that couples each element, and the inter-step capacitance is formed by using the pattern of the multilayer printed circuit board. It is a surface-mount small monolithic crystal filter that is formed by bonding with an adhesive, and can form a low-profile surface-mount crystal filter.

Further, according to the present invention, the display portion is provided on the ventral side of the metal clamp connecting the respective elements, and at the same time, the flat portion of the upper surface thereof can be used as an adsorption / desorption portion in a vacuum chuck, It has the advantage that it can be automatically mounted (solder reflow) and that it can be easily put into a taping packaging form, and it can be used for automatic mounting of electronic components.

[Brief description of drawings]

FIG. 1 is an assembly view and a side view of a surface mount type crystal filter of the present invention.

FIG. 2 is a diagram showing an embodiment of a printed circuit board for mounting a two-element filter coupled by a metal clamp.

FIG. 3 is a wiring pattern diagram of a multilayer substrate suitable for mounting a surface-mount type crystal filter.

FIG. 4 is a schematic view of a crystal filter which is a target of the present invention and 2
It is an equivalent circuit when used as an element.

FIG. 5 is an explanatory diagram when soldering the crystal filter to the substrate.

FIG. 6 shows another embodiment of mounting a crystal filter on a substrate.

FIG. 7 is an explanatory diagram for attaching a two-element crystal filter.

[Explanation of symbols]

 1 Input Terminal 2 Ground Terminal 3 Output Terminal 4 Metal Container 10 Metal Clamp 20 Wiring Board

Claims (2)

[Scope of utility model registration request] 1. A crystal filter that comprises a multi-pole monolithic crystal filter using at least two monolithic crystal filters composed of one element, wherein the cross section is such that the upper ends of the metal cases of the respective elements face each other. The metal clamp is inserted into a vertically elongated C-shaped cylindrical metal clamp, and the air-tight terminals drawn out from the external lead-out terminals of the respective elements are arranged integrally at both ends to form an integral structure with the metal clamp. A surface-emerging crystal filter, characterized in that the terminals are bent in an L shape. 2. The crystal filter is mounted on a multi-layered printed circuit board, and the inter-stage matching capacitance of each element is formed by patterning between the layers of the multi-layered printed circuit board. The surface mount crystal filter according to 1.