JP2009100098A - Surface mounting crystal oscillator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface mounting crystal oscillator which is prevented from electric breakdown of an IC chip during measurement to improve productivity and allows orientation from the side of a metal cover to be surely recognized. <P>SOLUTION: In the surface mounting crystal oscillator, the IC chip and a crystal piece are stored in a vessel body 1 made of laminated ceramics; external terminals 5 electrically connected to the IC chip are provided on outside bottoms in 4 corners of the vessel body 1; at least a power terminal and an earth terminal out of the external terminals 5 are provided in a pair of diagonal corners; an opening end surface of the vessel body 1 is provided with a metal film 6; a metal cover 4 electrically connected to the earth terminal out of the external terminals 5 is joined to the opening end surface to hermetically enclose at least the crystal piece; and the shape of the surface mounting crystal oscillator is rectangular when viewed from the side of the metal cover 4 and is point-symmetrical with respect to the center. A power terminal 13 for measurement is provided on an outside surface of the corner of the vessel body 1 where the power terminal out of the external terminals 5 is provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a surface mount crystal oscillator (hereinafter referred to as a surface mount oscillator), and more particularly to a surface mount oscillator that prevents electrical destruction of an IC chip when measuring oscillation characteristics.

(Background of the Invention)
Since the surface-mounted oscillator is small and light, it is built in a portable electronic device typified by a cellular phone as a frequency or time reference source. In recent years, there is much demand for cost reduction, and there is a demand for preventing the occurrence of defects in the production process, for example, preventing the electrical destruction of the IC chip when measuring the oscillation characteristics.

(Example of conventional technology)
FIG. 6 is a diagram of a surface-mount oscillator for explaining a conventional example, in which FIG. 6 (a) is a partially broken sectional view, FIG. 6 (b) is a plan view excluding a metal cover and a metal ring, FIG. ) Is a bottom view.

  The surface-mount oscillator is formed by housing an IC chip 2 and a crystal piece 3 in a container body 1 and covering a metal cover 4 in a hermetically sealed manner. The container body 1 is made of a laminated ceramic and has a concave shape with an inner wall step. The container main body 1 has an external terminal 5 for surface mounting on the outer bottom surface, and a metal film 6 on the opening end surface. The metal film 6 is electrically connected to the ground terminal 5 (GND) in the external terminal 5 through the electrode through hole 7 provided in the corner of the frame wall.

  The IC chip 2 integrates at least each element constituting the oscillation circuit (excluding the crystal resonator). When a stable temperature is obtained by compensating the frequency-temperature characteristics due to the crystal resonator, a temperature compensation mechanism is also integrated. The circuit function surface which is one main surface of the IC chip 2 has IC terminals (not shown) including crystal terminals and the like, and ultrasonic thermocompression bonding using bumps 8 on the circuit terminals provided on the inner bottom surface of the container body 1. By flip chip bonding.

  The power supply, output, ground, and AFC terminal, excluding the crystal terminal in the IC terminal, are electrically connected to the corresponding external terminals 5 through the laminated surface. The arrangement (position) of the external terminals 5 is standardized. For example, the frequency control terminal 5 (AFC), the ground terminal 5 (GND), and the output terminal 5 are clockwise when the lower left corner is the power supply terminal 5 (Vcc). (Vout).

  In the case of the temperature compensation type, a write terminal 9 a for writing temperature compensation data is provided on the outer surface of the container body 1. In this example, two dedicated write terminals 9a are provided on the outer surfaces facing each other in the long side direction. The crystal piece 3 has excitation electrodes (not shown) on both main surfaces, and extends extraction electrodes on both sides of one end. The extraction electrodes are formed by folding back on the opposite surfaces.

  Then, both ends of the extended end portion of the extraction electrode are fixed to a crystal terminal (not shown) of the inner wall step portion by, for example, the conductive adhesive 10. The crystal terminal is electrically connected to the IC terminal of the IC chip 2 through a conductive path (not shown). Here, the crystal terminal of the inner wall step portion extends as a crystal inspection terminal 9b also on the outer surface facing in the short side direction.

  The write terminal 9a and the crystal inspection terminal 9b are formed except for the uppermost layer and the lowermost layer of the multilayer ceramic in order to prevent an electrical short circuit. In this case, for example, depressions are formed in layers other than the uppermost layer. These are formed by so-called through-hole processing in which W (tungsten) is poured into a through-hole and fired in the form of a sheet-like ceramic, and are formed by being divided into individual container bodies 1.

  The metal cover 4 is joined by seam welding or the like to a metal ring (not shown) joined to the metal film 6 on the opening end face of the container body 1 by silver brazing or the like. Then, after the crystal piece 3 is hermetically sealed, the vibration characteristics of the crystal resonator (crystal piece 3) are inspected by the crystal inspection terminal 9b, and temperature compensation data is written from the write terminal 9a, so that a temperature compensation type surface mount oscillator To complete.

  Then, as shown in FIG. 7 (a), the surface mounting oscillator is accommodated (inserted) in the measuring jig 11 for convenience, and the external terminal of the container main body is connected to the measuring pin 12 protruding vertically from the bottom surface side. 5 is abutted and oscillation characteristics such as oscillation frequency are measured. The measurement pin 12 corresponds to the external terminal 5 in the clockwise direction, the power supply pin 12 (Vcc), the AFC pin 12 (AFC), the grounding pin 12 (GND), and the output pin 12 (Vout) located diagonally to the left. ).

Then, after measuring the oscillation characteristics of each surface-mount oscillator, defective products are eliminated and products are displayed on the metal cover 4 of only good products, including the origin indication.
JP 2007-104032 A

(Problems of conventional technology)
However, in the surface mount oscillator having the above configuration, when the surface mount oscillator to which the metal cover 4 is bonded is inserted into the measurement jig 11 to inspect the oscillation characteristics, the length direction of the surface mount oscillator is reversed and 180 degrees. When it is inverted and inserted into the measurement jig 11 (hereinafter also referred to as reverse insertion), there is a problem that the IC chip 2 is electrically damaged.

  That is, when the surface mount oscillator is reversely inserted into the measurement jig 11, each external terminal 5 comes into contact with the measurement pin 12 in the diagonal direction different from the original as shown in FIG. 7 (b). In this case, in particular, the ground terminal 5 (GND) contacts the power supply pin 12 (Vcc), and the ground pin 12 (GND) contacts the power supply terminal 5 (Vcc). Therefore, there is a problem in that an opposite power supply voltage is applied between the power supply terminal 5 (Vcc) and the ground terminal 5 (GND), and an excessive current is generated in the IC chip 2 to cause electrical breakdown.

  The reason why the surface mount oscillator is reversely inserted into the measurement jig 11 is that, for example, until the surface mount oscillator is completed and a product display including a frequency or the like is displayed on the surface of the metal cover 4, The left and right are symmetrical (FIG. 8). Therefore, it is difficult to confirm the directivity after inserting the surface mount oscillator.

  In these cases, normally, the shape of any one of the external terminals 5 of the four corners, for example, 5 (AFC) is changed as shown in FIG. 6 (c). Then, after the external terminal 5 (AFC) is image-recognized and directionality is confirmed, the surface mount oscillator is accommodated in the measurement jig 11. However, it may be accommodated in the reverse direction due to an image recognition failure or the like.

(Object of invention)
It is an object of the present invention to provide a surface mount oscillator that can prevent electrical breakdown of an IC chip during measurement and increase productivity, and can reliably recognize directionality from a metal cover side.

  According to the present invention, as shown in the claims (Claim 1), an IC chip and a crystal piece are accommodated in a container body made of laminated ceramic, and the outer bottom surface of the four corners of the container body is placed on the bottom surface. An external terminal electrically connected to the IC chip is provided, and at least the power supply terminal and the ground terminal in the external terminal are provided in a pair of diagonal portions, and a metal film is provided on the opening end surface of the container body In addition, a metal cover that is electrically connected to the ground terminal in the external terminal is joined and at least the crystal piece is hermetically sealed, and the shape viewed from the metal cover side is rectangular and point-symmetric with respect to the center. In the surface mount crystal oscillator, a power supply terminal for measurement is provided on the outer surface of the corner portion of the container body provided with the power supply terminal in the external terminal.

  With such a configuration, as in the conventional case, the grounding terminal is the bottom surface and the grounding pin of the measuring jig is in contact with the vertical direction, and the measuring jig is connected to the power supply terminal extending to the outer surface in the present invention. If the power supply pin is brought into contact with the horizontal direction, even if the length direction of the surface mount oscillator is inserted in the measuring jig in the reverse direction, the power supply pin does not contact the ground terminal. Therefore, since no power supply voltage is supplied to the IC chip, electrical breakdown due to excessive current can be prevented.

(Embodiment section)
According to a second aspect of the present invention, in the first aspect, the power supply terminal for measurement is formed in a first recess provided on an outer surface of a container body made of the laminated ceramic and having an open end surface. The depression has a flat surface with which an external measurement pin comes into contact. This ensures that the measurement pin comes into contact with the power supply terminal.

  In Claim 3, in Claim 2, the first recess is formed so as to reach at least the opening end surface of the container body, and the uppermost layer of the container body made of the laminated ceramic is used as an electrode, and from the metal cover side. The viewed planar shape is asymmetric with respect to the center.

  Thereby, since the 1st hollow reaches the opening end face and is formed, the 1st hollow can be visually recognized from the metal cover side, and the plane shape is made asymmetric with respect to the center when viewed from the metal cover side. Therefore, the directionality of the surface mount oscillator can be recognized even after being inserted into the measurement jig. And since the uppermost layer of a 1st hollow is made into an electrodeless, the electrical short circuit with the metal film and metal cover of the opening end surface of a container main body is prevented.

  In the fourth aspect of the present invention, in the first aspect, a ground terminal for measurement is provided on the outer surface of the corner portion of the container body provided with the ground terminal in the external terminal, and the power terminal and the ground terminal are connected to each other. The principal surface direction is the orthogonal direction.

  As a result, if the power supply and grounding pins of the measurement pins are configured to contact the power supply and grounding terminals vertically from the horizontal direction, the surface mount oscillator is inserted into the measurement jig in the reverse direction. The grounding pin does not contact either the power supply terminal or the grounding terminal. Therefore, since no excessive current is generated in the IC, the electrical breakdown of the IC can be prevented.

  In Claim 5, in Claim 1, a set of outer faces of the container body facing each other has an inspection terminal of a crystal resonator, and another set of outer faces of the container body facing each other has a temperature. It has a compensation data write terminal. Even in these cases, the surface mount oscillator which is asymmetrical when viewed from the metal cover side can be obtained by the configuration of the first aspect.

(First embodiment)
FIG. 1 is a diagram of a surface mount oscillator for explaining a first embodiment of the present invention. FIG. 1 (a) is a side view, FIG. 1 (b) is a bottom view, and FIG. 1 (c) is a plan view. 1 (b) is the same as FIG. 6 (c) in the prior art, and the same parts as those in the previous prior art are given the same reference numerals and the description thereof will be simplified or omitted.

  As described above, the surface-mount oscillator includes the IC chip 2 on the inner bottom surface of the container body 1 made of multilayer ceramic and the inner wall stepped portions on both ends of the crystal piece 3 from which the extraction electrode extends. The metal cover 4 is covered and hermetically sealed. The container body 1 has an external terminal 5 for surface mounting on the outer bottom surface, and a metal film 6 electrically connected to the ground terminal in the external terminal 5 on the opening end surface. A metal ring is brazed to the opening end face, and the metal cover 4 is joined by seam welding.

  In this example, the IC chip 2 also integrates the oscillation circuit and the temperature compensation mechanism to make the surface mount oscillator a temperature compensation type. Then, one main surface (circuit function surface) of the IC chip 2 has an IC terminal including a crystal terminal and the like, and the power supply, output, ground, and AFC terminal are electrically connected to the external terminals 5 corresponding thereto. Then, two dedicated writing terminals 9a for the temperature compensation data are provided on a pair of outer side surfaces facing each other in the long side direction of the container body 1, and are connected to corresponding IC terminals.

  The crystal piece 3 is electrically connected to the crystal terminal of the IC chip 2 by fixing both sides of the extended end portion of the extraction electrode to the crystal terminal of the inner wall stepped portion by the conductive adhesive 10 or the like. The crystal terminal of the inner wall step portion also extends as a crystal inspection terminal 9b on the outer surface of another set facing each other in the short side direction. The crystal inspection terminal 9b and the write terminal 9a are formed except for the uppermost layer and the lowermost layer of the laminated ceramic in order to prevent an electrical short circuit.

  In this embodiment, the measurement external terminal 13 (Vcc) is provided outside the corner portion where the power supply terminal 5 (Vcc) is provided, separately from the power supply terminal 5 (Vcc) provided on the outer bottom surface of the container body 1. Also provided on the side. The power supply terminal 13 (Vcc) for measurement is formed in a first recess 14a formed by a through hole provided on the outer surface, and has a wide flat portion on which the measurement pin 12 can come into contact.

  In this example, the first recess 14a is formed so as to reach the opening end surface excluding at least the lowest layer of the multilayer ceramic, and the uppermost layer has no electrode. In short, the 1st hollow 14a is exposed to an opening end surface. The power supply terminal 13 (Vcc) for measurement extends from the power supply terminal of the IC chip 2 to the first recess 14a on the outer surface through the laminated surface.

  Here, except for the power supply terminal 5 (Vcc), the external terminals 5 such as the ground terminal 5 (GND) are only on the bottom surface of the container body 1, and these external terminals 5 for measurement are not provided on the outer surface. . However, a conventional end face electrode having a narrow width that makes it difficult to contact the measuring pin 12 for a solder fillet is provided at the corner. Also here, the arrangement of the external terminals 5 is the same as in the prior art, and the power supply terminal 5 (Vcc) and the ground terminal 5 (GND) are arranged in a pair of diagonal portions (upward diagonal direction) of the container body. Provided.

  In such a case, as shown in FIG. 2 (a), the power supply pin 12 (Vcc) of the measurement pins 12 in the measurement jig 11 protrudes in the horizontal direction by an elastic mechanism (not shown), and other earthing is provided. The measuring pin 12 including the working pin 12 (GND) protrudes in the vertical direction from the bottom side as in the prior art. The power supply pin 12 (Vcc) is in contact with the measurement power supply terminal 13 (Vcc) extending from the outer surface of the surface mount oscillator (container body 1) from the horizontal direction, and the other measurement pins 12 are ground terminals. The external terminal 5 including 5 (GND) contacts from the vertical direction.

  Therefore, when the surface mount oscillator is inserted into the measurement jig 11 and the directionality of the surface mount oscillator is correct, the power supply pin 12 from the horizontal direction is connected to the power supply terminal 13 (Vcc) for measurement provided on the outer surface. (Vcc), the grounding pin 12 (GND) or the like from the vertical direction reliably contacts the grounding terminal 5 (GND) or the like on the bottom surface. Thereby, the oscillation characteristic can be measured correctly.

  On the other hand, as shown in FIG. 2 (b), when the surface mount oscillator is reversely inserted into the measuring jig 11, the power supply pin 12 (Vcc) is the corner where the ground terminal 5 (GND) is located. It contacts the outer surface of the part. In this case, the ground terminal 5 (GND) is the bottom surface only and the outer surface is electrodeless. Therefore, the power supply voltage from the power supply pin 12 (Vcc) is not supplied to any external terminal as well as the ground terminal 5 (GND).

  For these reasons, even if the surface mount oscillator is reversely inserted into the measurement jig 11, the power supply voltage is not supplied to the IC chip 2, so that an electrical breakdown can be prevented without causing an excessive current in the IC chip. And the oscillation characteristic can be measured by taking out the real surface oscillator reversely inserted from the measuring jig 11 and inserting it correctly. Therefore, productivity can be improved without wasting expensive ICs.

  In this embodiment, the first recess 14 a extending from the power supply terminal 13 (Vcc) for measurement is exposed on the opening end surface of the container body 1. When viewed from the metal cover side, the presence of the first depression 14a is asymmetric with respect to the center of the planar shape of the surface mount oscillator. Therefore, even after the surface mount oscillator is inserted into the measurement jig 11, the directionality seen from the metal cover side can be recognized, and reverse insertion of the measurement jig itself is prevented.

  In this example, since any one of the external terminals 5 provided on the bottom surface of the container body 1 has a different shape, it can be recognized from either the bottom surface or the metal cover 4 side. Accordingly, the directionality from either side can be recognized as necessary. Furthermore, since the uppermost layer of the first recess 14a is electrodeless, it is possible to prevent an electrical short circuit between the measurement power supply terminal 13 (Vcc) extending to the outer surface, the metal film 6, and the metal cover 4.

(Second Embodiment)
FIG. 3 is a plan view of a surface mount oscillator for explaining a second embodiment of the present invention. In addition, description of the same part as previous embodiment is abbreviate | omitted or simplified.

  In the second embodiment, not only the power supply terminal 13 (Vcc) for measurement but also the ground terminal 5 (GND) in the diagonal direction (a pair of diagonal portions) is used as the measurement ground terminal 13 (GND). Provided on the outer surface of the container body 1. The measurement ground terminal 13 (GND) extends from the IC chip 2 through the laminated surface of the container body 1 in the same manner as the power supply terminal 13 (Vcc), and reaches the opening end surface by through-hole processing. Formed.

  The flat surfaces of the first recess 14a of the power supply terminal 13 (Vcc) for measurement and the second recess 14b of the ground terminal 13 (GND) are the main surfaces of the power supply terminal 5 (Vcc) and the ground terminal 5 (GND). The plane directions are orthogonal to each other. The output terminal 5 (Vout) and the AFC terminal 5 (AFC) are only on the bottom surface.

  In such a case, as shown in FIG. 4, among the measurement pins 12 in the measurement jig 11, the power supply pins 12 (Vcc) and the ground pins 12 (GND) protrude from the horizontal direction perpendicular to each other. To do. Then, the power supply terminal 13 (Vcc) for measurement provided on the outer surface of the container body 1 is in contact with the ground terminal 13 (GND). External terminals other than these (output and AFC terminals) are in the vertical direction from the bottom as in the prior art.

  Therefore, even in this case, if the surface mount oscillator is correctly inserted into the measuring jig 11, "FIG. 4 (a)", the power supply pin 12 (Vcc) and the ground pin 12 (GND) are connected to the power supply terminal 13 ( Vcc) and ground terminal 13 (GND) can be reliably contacted to measure the oscillation characteristics of the surface mount oscillator.

  On the other hand, when the surface mount oscillator is reversely inserted into the measurement jig 11, "FIG. 4 (b)", the power supply pin 12 (Vcc) and the ground pin 12 (GND) are the power supply terminals for measurement. 13 (Vcc) and the outer surface on which the ground terminal 13 (GND) is provided are in contact with the outer surface which is adjacent to the non-electrode. Therefore, the power supply pin 12 (Vcc) does not contact the ground terminal 5 (GND) on the outer bottom surface.

  For these reasons, as in the first embodiment, even if the surface mount oscillator is reversely inserted, the power supply voltage is not supplied from the power supply pin 12 (Vcc) to the ground terminal 5 (GND). In this example, the ground pin 12 (GND) does not contact the power supply terminal 5 (Vcc). Therefore, the power supply and grounding pins 12 (Vcc) and (GND) are not in contact with either the power supply terminal 5 (Vcc) or the grounding terminal 5 (GND), so that the electrical destruction of the IC chip 2 can be reliably prevented. Productivity.

  In the second embodiment, the external terminals 5 provided on the other diagonal portion other than the power supply and ground terminals 5 (Vcc, GND) are provided on the outer bottom surface of the container body 1. For example, FIG. As shown, these external terminals (output and AFC terminals) may also be provided on the outer surface. In this case, the measurement pins 12 (power supply, ground, output, and AFC terminal pins) of the measurement jig 11 are projected in the horizontal direction and abut on the respective measurement terminals from the horizontal direction.

  The measurement output terminal 13 (Vout) and the AFC terminal 13 (AFC) extending to the outer surface of the diagonal portion of the other set are orthogonal to each other. In this example, the power supply terminal 13 (Vcc) for measurement and the output terminal 13 (Vout) are on the same side, and the ground terminal 5 (GND) and AFC5 (AFC) are on opposite sides.

  In this way, when the surface mount oscillator is reversely inserted into the measurement jig 11, not only the power supply and grounding pins 12 (Vcc, GND) but also the output and AFC pins 12 (Vout, AFC) The abutment is in contact with the outer surface which is electrodeless. Therefore, we will be fully prepared for reverse insertion.

(Other matters)
In the embodiment described above, the container body 1 has a concave shape having inner wall step portions. For example, the main body 1 has concave portions on both main surface sides and accommodates the crystal piece 3 on one side and hermetically encloses the IC chip 2 on the other side. Even in this case, the same applies. Further, although the temperature compensation type is adopted, the present invention can be similarly applied even when the temperature compensation mechanism is not provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure of the surface mount oscillator explaining 1st Embodiment of this invention, The figure (a) is a side view, The figure (b) is a bottom view, The figure (c) is a top view. FIG. 5 is a schematic plan view in which a surface mount oscillator is inserted into a measurement jig for explaining the operation of the first embodiment of the present invention. It is a top view of the surface mount oscillator explaining 2nd Embodiment of this invention. It is the typical top view which inserted the surface mount oscillator in the measuring jig explaining the effect | action of 2nd Embodiment of this invention. It is the typical top view which inserted the surface mount oscillator in the measuring jig explaining other embodiment of this invention. It is a top view of the surface mount oscillator explaining an example. It is a figure of the surface mount oscillator explaining a prior art example, the figure (a) is a partially broken sectional view, the figure (b) is a plan view excluding a metal cover and a metal ring, and the figure (c) is a bottom view. is there. It is the typical top view which inserted the surface mount oscillator in the measuring jig explaining the conventional problem. It is a top view of the surface mount oscillator in a prior art example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Container body, 2 IC chip, 3 Crystal piece, 4 Metal cover, 5 External terminal, 6 Metal film, 7 Electrode through-hole, 8 Bump, 9a Writing terminal, 9b Crystal inspection terminal, 10 Conductive adhesive, 11 Measurement Jig, 12 measuring pins, 13 external terminals for measurement, 14 depressions.

Claims (5)

  An IC chip and a crystal piece are accommodated in a container body made of a multilayer ceramic, and external terminals electrically connected to the IC chip are provided on the outer bottom surfaces of the four corners of the container body. At least the power supply terminal and the ground terminal are provided at a pair of diagonal portions, and a metal film is provided on the opening end surface of the container body and a metal cover electrically connected to the ground terminal in the external terminal is joined. Then, at least the crystal piece is hermetically sealed, and the shape viewed from the metal cover side is a rectangular shape and is a point-symmetric crystal oscillator with respect to the center, and the power supply terminal in the external terminal is provided. A crystal oscillator for surface mounting, wherein a power supply terminal for measurement is provided on an outer surface of a corner portion of the container body.   In Claim 1, the said power supply terminal for a measurement is formed in the 1st hollow provided in the outer surface of the container main body which consists of the said laminated ceramic and has an opening end surface, and the said 1st hollow has a measurement pin from the outside. A crystal oscillator for surface mounting having a flat surface to be in contact with.   3. The first recess according to claim 2, wherein the first recess is formed so as to reach at least the opening end surface of the container body, and the uppermost layer of the container body made of the laminated ceramic is made an electrodeless, and the planar shape viewed from the metal cover side is the center. A crystal oscillator for surface mounting that is asymmetrical to the above.   The ground terminal for measurement is provided on the outer surface of the corner portion of the container body provided with the ground terminal in the external terminal, and the main surface direction of the power supply terminal and the ground terminal is an orthogonal direction. A crystal oscillator for surface mounting.   2. The temperature compensation data writing terminal according to claim 1, wherein a pair of outer side faces of the container main body have inspection terminals for crystal resonators, and another pair of outer side faces of the container main body face each other. Surface mount crystal oscillator with