JP2009164672A - Quartz oscillator and manufacturing method thereof - Google Patents

Abstract

The present invention provides a crystal oscillator in which protrusions of a metal pin can be arbitrarily set to improve productivity and a method for manufacturing the same.
A base 2 on which a metal pin 1 having a positioning protrusion 7 is provided on the front end side, and a circuit board 5 which has a through hole inserted through the metal pin 1 and is positioned and supported by the protrusion. In the crystal oscillator having the crystal resonator 3 and the circuit element 4 disposed on the circuit board 5, the positioning protrusion 7 is formed by crushing after the metal pin 1 is erected on the base 2. The formed structure and the manufacturing method thereof are used.
[Selection] Figure 1

Description

  The present invention relates to a crystal oscillator and a manufacturing method thereof, and more particularly to a constant temperature crystal oscillator having a two-stage structure with metal pins.

(Background of the Invention)
Crystal oscillators are widely used as communication frequency sources as frequency reference sources. One of these is a constant temperature crystal oscillator built in a communication device of a base station or a relay station in which the operating temperature of the crystal resonator is kept constant and the oscillation frequency is kept highly stable.

(Example of conventional technology)
FIGS. 5A and 5B are diagrams for explaining a conventional example. FIG. 5A is a sectional view of a crystal oscillator, and FIG. 5B is a plan view of a metal pin.

  The crystal oscillator includes a base 2 on which metal pins 1 are erected, a circuit board 5 on which a crystal resonator 3 and circuit elements 4 are disposed, and a cover 6. The metal pin 1 has a disc-like positioning projection (circular projection) 7 on the tip side. The positioning protrusion 7 is formed in advance on the metal pin 1 by molding with a mold or the like. The base 2 is made of, for example, a metal base having a rectangular shape in plan view, and the metal pin 1 is inserted through the four through holes. However, the through holes are hermetically sealed by the glass 8 and insulated.

  The quartz crystal resonator 3 is formed by, for example, sealing and enclosing an AT cut or SC cut crystal piece 3a in, for example, a metal container 3b, and a pair of lead wires 3c extending from one end side. The circuit element 4 includes a variable impedance element such as a trimmer capacitor 4a for adjusting the oscillation characteristics, or an oscillation element including an oscillation amplifier (not shown), a heating chip resistor, a temperature sensitive element (thermistor), and a temperature control element including a power transistor. Consists of.

  The circuit board 5 is a double-sided board made of, for example, a glass epoxy material. On the upper surface side of the circuit board 5, the circuit element 4 mainly including an oscillation element including the trimmer capacitor 4a is disposed. On the lower surface side of the circuit board 5, a chip resistor for heat generation in the temperature control element, a temperature sensitive element (thermistor), a power transistor, and the crystal resonator 3 are disposed.

  The crystal unit 3 (metal container) is disposed so as to face the chip resistor for heating, the temperature sensitive element (thermistor), and the power transistor with the main surface as the plate surface direction of the circuit board 5. The pair of lead wires 3c extend to the upper surface side of the circuit board 5 and are connected by solder or the like (not shown). Here, between these temperature control elements and the main surface of the crystal unit 3, a thermally conductive sheet or resin 8 is in close contact.

  Then, the circuit board 5 on which the crystal resonator 3 and the circuit element 4 are arranged is inserted into the tip side of the metal pin 1 through holes provided at the four corners, and is positioned and supported by the circular protrusion 7. Is done. The tip of the metal pin 1 protruding from the circuit board 5 is fixed to the circuit pattern by the solder 9.

  Thereafter, the oscillation characteristics including the oscillation frequency are adjusted by a variable impedance element such as a trimmer capacitor 4a on the upper surface side of the circuit board 5. And the metal cover 6 is covered on the metal base 2, and both flanges are joined by resistance welding.

  In such a case, the heat source that makes the crystal oscillator a constant temperature type is based on a chip resistor for heating (and a power transistor) in particular, and does not use a conventional constant temperature bath with a hot wire wound. Can promote. The power transistor that supplies power to the temperature sensitive element is used as a heat source because it generates a large amount of heat.

The temperature control element (the chip resistor for heating, the power transistor and the temperature sensitive element) is on the lower surface side of the circuit board 5 same as that of the crystal unit 3, and the thermal resonator sheet or the resin 8 is interposed between the crystal unit 3 and the crystal unit 3. It is placed facing one main surface. Therefore, the chip resistor for heat generation and the heat source of the power transistor can be used effectively, and the operating temperature of the crystal unit 3 can be detected in real time by the temperature sensitive element. Here, since the trimmer capacitor 4a is on the upper surface side of the circuit board 5, the oscillation frequency can be easily adjusted.
Japanese Patent Laid-Open No. 2007-110698 JP 2005-341191 A JP 2006-324936 A

(Problems of conventional technology)
However, in the crystal oscillator configured as described above, the metal pin 1 having the circular protrusion 7 is integrally formed when the metal base 2 is formed, and the height of the circular protrusion 7 from the inner bottom surface of the metal base 2 is determined in advance. Is done. In this case, the position of the circular protrusion 7 is determined in consideration of the height h1 from the lower surface of the circuit board 5 to the crystal unit 3 and the height h2 from the upper surface of the circuit board 5 to the trimmer capacitor 4a having the largest height. It is determined.

  Note that the height of the metal pin 1 may be larger than that of the trimmer capacitor 4a due to a manufacturing error or the like. Further, not only the trimmer capacitor 4a but also a variable impedance element such as a variable resistance element for controlling the oscillation characteristics is relatively high.

  Normally, the distance d1 from the crystal unit 3 to the metal base 2 and the distance d2 from the trimmer capacitor 4a to the metal cover 6 are set to a minimum (for example, 1 mm or less) and an even distance so as not to contact each other. Thereby, for example, while miniaturization is promoted, the space product in the container is reduced and the heat source is effectively utilized. In addition, the atmosphere of the space product is reduced, and heat transfer due to convection is suppressed, thereby eliminating the adverse effects caused by uneven thermal distribution.

  For these reasons, the height from the circuit board 5 to the crystal unit 3 is particularly high, depending on the design for satisfying the specifications, even if the basic structure of the constant temperature type using the heating chip resistor is the same. Is slightly changed, the metal pin 1 having the circular protrusion 7 is required at a position corresponding to the height. Although the trimmer capacitor 4a and the metal pin 1 are also factors that change the height, a change in height up to the crystal unit 3 is most affected.

  However, since the metal pin 1 is manufactured by being integrated with the metal base 2 in advance, it is troublesome to stock the metal base 2 with slightly different heights of the circular protrusions 7 according to each specification. In the case of production with a small amount of other varieties, there is a problem that the productivity is lowered particularly because the parts cannot be shared.

  There are also errors in the height h1 from the circuit board 5 to the crystal resonator 3 and the height of the circuit element 4 of the trimmer capacitor, including the position of the circular protrusion 7. Therefore, when these errors are taken into account, when the position of the circular protrusion 7 is set in advance after the actual assembly operation, the distance d1 to the metal base 2 and the distance d2 to the metal cover 6 are made equal. There was also a problem.

(Object of invention)
An object of the present invention is to provide a crystal oscillator in which protrusions of metal pins can be arbitrarily set and productivity is improved, and a manufacturing method thereof.

  The present invention, as shown in the claims (Claim 1), has a base in which a metal pin having a positioning projection on the tip side is erected, and a through-hole inserted into the metal pin. A crystal oscillator having a circuit board 5 positioned and supported by a protrusion, and a crystal resonator and a circuit element disposed on the circuit board, wherein the positioning protrusion is a linear metal pin on the base It is set as the structure formed by crushing processing after standing up.

  According to a third aspect of the present invention, there is provided a base in which a metal pin having a positioning protrusion on the tip side is erected, a circuit board having a through-hole inserted into the metal pin and supported by the metal pin, In a method of manufacturing a crystal oscillator having a crystal resonator and a circuit element disposed on the circuit board, a first step of forming a base in which linear metal pins not having the positioning protrusions are erected, and After the first step, a second step of inserting the through hole of the circuit board on which the crystal resonator and the circuit element are mounted into the linear metal pin, and a tip side of the linear metal pin And a third step of forming the position protrusions by crushing.

  With such a configuration according to claim 1, since the positioning protrusion is formed by crushing after standing on the base, the position is determined based on, for example, the arrangement state of the crystal resonator and the circuit element with respect to the circuit board. The fixing protrusion can be formed at an arbitrary position. Therefore, the base can be made common to various specifications, so that productivity can be improved.

  According to the manufacturing method of claim 3, after the first step of forming the base in which the straight metal pins are erected, the second step of inserting the circuit board into the metal pins, and the position by crushing the metal pins Forming a decision part. Therefore, the positioning protrusion can be formed at an arbitrary position based on the arrangement state of the crystal resonator and the circuit element with respect to the circuit board. As a result, the base can be made common to various specifications, so that productivity can be improved.

(Embodiment of claim 1)
According to a second aspect of the present invention, in the first aspect, the circuit element includes an oscillation element including a variable impedance element and a temperature control element of the crystal resonator including a chip resistor for heat generation. The variable impedance element is disposed on the lower surface of the circuit board facing the base, and the variable impedance element is disposed on the upper surface of the circuit board opposite to the lower surface on which the crystal resonator is disposed.

  According to this, since the crystal resonator is disposed on the lower surface of the circuit board and the variable impedance element is disposed on the upper surface opposite to the crystal resonator, the oscillation characteristics can be easily adjusted. If the quartz resonator is placed on the upper surface of the circuit board in the same manner as the variable impedance element, the variable impedance element is relatively large, which is disadvantageous in terms of arrangement space and workability. Further, not only the variable impedance, for example, a trimmer capacitor, but also a fixed capacitor or an inductor is used, adjustment is facilitated.

(Embodiment of claim 3)
According to Claim 4, the third step is carried out in a state in which the through hole of the circuit board is inserted into the linear metal pin after the second step. Thus, the positioning protrusion is formed on the metal pin in a state where the circuit board on which the crystal resonator and the circuit element are arranged is inserted into the metal pin (second process) (third process). Therefore, the positioning protrusion can be formed at an appropriate position based on the actual arrangement state of the crystal resonator and the circuit element with respect to the circuit board including the design error.

  In the fifth aspect, the second step is performed after the third step in the third aspect. Even in this case, it is possible to confirm the position of the crystal resonator and the circuit element with respect to the circuit board and form the positioning protrusion at an appropriate position. In this case, the positioning protrusion may be formed after inserting the metal board into the metal pin of the circuit board to confirm the position and removing the circuit board from the metal pin.

  In the sixth aspect of the present invention, the circuit element according to the third aspect includes an oscillation element including a variable impedance element and a temperature control element of the crystal resonator including a chip resistor for heat generation. The variable impedance element is disposed on the upper surface of the circuit board that is opposite to the lower surface on which the crystal resonator is disposed. As in the second aspect, the oscillation frequency can be easily adjusted.

(First embodiment, equivalent to claims 1 and 2)
1 and 2 are diagrams for explaining a first embodiment of the present invention. FIG. 1 is a sectional view of a crystal oscillator which is the same as FIG. 4 (a), and FIG. 2 (a) is a metal. The general front view of a pin, the figure (b) is the side view, and the figure (c) is a top view. In addition, the same number is attached | subjected to the same part as a prior art example, and the description is simplified or abbreviate | omitted.

  As described above, the crystal oscillator supports the circuit board 5 on the positioning protrusion 7 of the metal pin 1 erected on the metal base 2. The circuit element 4 including the trimmer capacitor 4a is provided on the upper surface of the circuit board, and the main surface is provided on the lower surface by the chip resistor for heating, the temperature sensitive element, the power transistor, and the conductive sheet or resin 8 in the temperature control element. A quartz crystal resonator 3 to which is thermally coupled is disposed.

  In this embodiment, after the linear metal pin 1 without the positioning protrusion 7 is erected on the metal base 2, the positioning protrusion 7 is formed by crushing. That is, in the conventional example, the metal pin on which the positioning protrusion (annular protrusion) 7 is formed is inserted into the through hole of the metal base 2 to sinter the glass. Here, however, the straight metal pin is inserted and the glass is sintered. Is sintered.

  Then, with the straight metal pins 1 standing on the metal base 2, the recesses 10 are provided on both main surfaces by, for example, crushing from both sides on the tip side of the metal pins 1, thereby orthogonal to the pressing direction. The positioning protrusion 7 projects in the direction. The positioning protrusion 7 can protrude in an arbitrary direction.

  If the positioning protrusion 7 is formed by the crushing process, the positioning protrusion 7 can be formed at an arbitrary position based on the arrangement state of the crystal resonator 3 and the circuit element 4 with respect to the circuit board 5. That is, the height of the crystal unit 3 and the trimmer capacitor 4a from the circuit board 5 is recognized. Based on this, the positioning projection 7 is made into a metal pin by crushing so that the distance d1 of the crystal resonator 3 to the metal base 2 and the distance d2 of the trimmer capacitor 4a to the metal cover 6 are both within 1 mm. Can be formed. Therefore, the base can be made common to various specifications, so that productivity can be improved.

(Embodiment 2 corresponds to claims 3, 4 and 6)
When manufacturing the surface mount oscillator having the above-described configuration, for example, after the first step in which the straight metal pins 1 are erected on the metal base, the four corners of the circuit board in which the crystal resonator and the circuit elements are arranged on both main surfaces are provided. A second step of inserting the through-hole of the portion into the metal pin 1 and a third step of forming the position projection 7 by crushing on the tip side of the linear metal pin 1.

  Here, after the first step, the second step is carried out, and the circuit board 5 is inserted into the linear metal pin 1 as shown in FIG. 3 (a). The distance d1 from 3 to the metal base 2 is estimated and temporarily fixed by a jig or the like (not shown). In this case, of course, the distance d2 from the trimmer capacitor 4a to the metal cover 6 is also taken into consideration.

  Then, with the circuit board 5 temporarily fixed, the positioning protrusions 7 are formed on the metal pins 1 by crushing (FIG. 3B). Thereafter, as in the prior art, the metal pins 1 protruding on the circuit board 5 and the circuit pattern are connected by solder. Then, the trimmer capacitor 4a is adjusted to adjust the oscillation characteristics, and the metal cover 6 is joined by resistance welding (the previous FIG. 1).

  In such a manufacturing process (method), the distance d1 of the crystal resonator with respect to the metal base 2 can be directly visually measured including the design error, and the distance d2 from the trimmer capacitor 4a to the metal base 2 can be measured. In consideration, the positioning protrusion 7 can be formed at an appropriate position of the metal pin 1.

(Embodiment 3 corresponds to claims 3, 5, and 6)
In the third embodiment, a positioning protrusion is provided on the metal pin 1 erected on the metal base 2 (third step). In this case, the position of the crystal resonator 3 and the circuit element 4 disposed on the circuit board 5 is confirmed in advance, and the positioning protrusion 7 is formed at an appropriate position of the metal pin 1. For example, after the circuit board 5 is inserted into the metal pin 1 and the position state is confirmed, the circuit board is removed. In this case, it is possible to mark the position where the positioning protrusion is formed.

  Thereafter, the circuit board (through hole) on which the crystal resonator 3 and the circuit element 4 are arranged is inserted into the metal pin 1 and supported by the positioning protrusion. Then, as described above, the tip end side of the metal pin 1 is fixed with solder and the oscillation characteristics are adjusted, and then the metal cover is joined and hermetically sealed.

  Even in this case, as in the second embodiment, the distance d1 of the crystal resonator with respect to the metal base 2 and the distance d2 from the trimmer capacitor 4a to the metal base 2 including the design error can be grasped, and the positioning protrusion 7 can be determined. The metal pin 1 can be formed at an appropriate position.

(Other matters)
In the above embodiment, the heat generating resistor chip, the temperature sensitive element and the power transistor in the temperature control element, and the heat transfer sheet and the resin 8 are interposed between the crystal unit 3, but other structures such as a metal plate are used. Needless to say, the present invention can be applied even if it has a structure that interposes. Further, the base 2 is a metal base. However, as shown in FIG. 4, for example, as shown in FIG.

It is sectional drawing of the crystal oscillator explaining 1st Embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS The front view of the metal pin explaining 1st Embodiment of this invention, the same figure (b) is the side view, The figure (c) is a top view. It is a figure explaining 2nd Embodiment of this invention, The figure (ab) is a partial cross section figure of a crystal oscillator. It is sectional drawing of the surface mount oscillator which shows the other example of this invention. It is a figure explaining a prior art example, the figure (a) is a sectional view of a crystal oscillator, and the figure (b) is a top view of a metal pin.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Metal pin, 2 base, 3 crystal oscillator, 4 circuit element, 4a trimmer capacitor, 5 circuit board, 6 cover, 7 positioning protrusion, 8 heat conductive sheet or resin, 9 solder, 10 recess, 11 mounting Terminal.

Claims (6)

  A base in which a metal pin having a positioning projection on the tip side is erected, a circuit board having a through-hole inserted into the metal pin and positioned and supported by the projection, and disposed on the circuit board A crystal oscillator having a crystal oscillator and a circuit element, wherein the positioning protrusion is formed by crushing after a linear metal pin is erected on the base.   2. The circuit element according to claim 1, wherein the circuit element includes an oscillation element including a variable impedance element and a temperature control element of the crystal resonator including a chip resistor for heat generation, and the crystal resonator is formed on the circuit board facing the base. A crystal oscillator disposed on a lower surface, wherein the variable impedance element is disposed on an upper surface of a circuit board opposite to the lower surface on which the crystal resonator is disposed.   A base on which a metal pin having a positioning protrusion on the tip side is erected, a circuit board having a through-hole inserted into the metal pin and supported by the metal pin, and a crystal disposed on the circuit board In a method of manufacturing a crystal oscillator having a vibrator and a circuit element, a first step of forming a base in which a linear metal pin not having a positioning protrusion is erected, and after the first step, the crystal vibration A second step of inserting the through hole of the circuit board on which a child and a circuit element are mounted into the linear metal pin; and forming the position protrusion by crushing on the tip side of the linear metal pin. A method for manufacturing a crystal oscillator comprising a third step.   4. The method for manufacturing a crystal oscillator according to claim 3, wherein after the second step, the third step is performed in a state where a through hole of the circuit board is inserted into the linear metal pin.   4. The method for manufacturing a crystal oscillator according to claim 3, wherein the second step is performed after the third step.   4. The circuit element according to claim 3, wherein the circuit element includes an oscillation element including a variable impedance element, and a temperature control element of the crystal resonator including a chip resistor for heating, and the crystal resonator is formed on the circuit board facing the base. A method for manufacturing a crystal oscillator, wherein the variable impedance element is disposed on a lower surface, and the variable impedance element is disposed on an upper surface of a circuit board opposite to the lower surface on which the crystal resonator is disposed.