JP2007288743A - Crystal oscillator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a crystal oscillator which facilitates charging with underfill agents or connection of wire bonding, and can be miniaturized. <P>SOLUTION: A plurality of connector chips 17, constituting a spacer component, are fixed on the surface of a circuit board 5. The plurality of connector chips 17 are disposed, while being distributed to make an integrated circuit element 7 visible from a lateral direction that is orthogonal to the direction of stacking of a first unit 1 and a second unit 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a crystal oscillator.

  Japanese Patent No. 2960374 discloses a crystal oscillator in which a ceramic first container and a second container are stacked one above the other. The first container has an integrated circuit element disposed on the surface of the bottom wall and an annular peripheral wall (spacer means) fixed on the peripheral edge of the bottom wall. The second container is fixed on the peripheral wall of the first container so as to completely cover the opening of the first container with a predetermined space between the second container and the integrated circuit element. A crystal resonator made of a crystal blank is accommodated in the second container.

In this type of crystal oscillator, in order to reinforce the mechanical joint between the bottom wall of the first container and the integrated circuit element, electrical insulation is provided at least between the surface of the bottom wall and the integrated circuit element. It is filled with a reinforcing filler having a property (underfill agent). Also, this type of crystal oscillator substrate includes a type of crystal oscillator in which an electrode of an integrated circuit element and an electrode formed on a first container are electrically connected by wire bonding.
Japanese Patent No. 296037

  However, as described above, for example, when the underfill agent is filled using a nozzle, the smaller the overall size, the more the nozzle comes into contact with the peripheral wall of the container, resulting in a problem of poor workability. Therefore, there is a limit to reducing the size of the crystal oscillator in order to sufficiently fill the underfill agent.

  Further, even in a crystal oscillator of a type that is connected by wire bonding, if the overall dimensions are reduced, the capillary for performing wire bonding may come into contact with the peripheral wall of the container, and the bonding operation may not be performed smoothly. Therefore, there is a limit to downsizing even a crystal oscillator of a type that performs wire bonding.

  An object of the present invention is to provide a crystal oscillator that can be easily downsized.

  Another object of the present invention is to provide a crystal oscillator that can be easily filled with an underfill agent.

  Another object of the present invention is to provide a crystal oscillator that can be easily connected by wire bonding.

  A crystal oscillator to be improved by the present invention includes a first unit having an integrated circuit element disposed on a surface of a circuit board and spacer means fixed on a peripheral portion of the surface of the circuit board, and an integrated circuit. And a second unit that is fixed on the spacer means with a predetermined gap between the element and having a crystal resonator inside. As the circuit board, any material may be used. The integrated circuit element and the crystal resonator are electrically connected. In the present invention, the spacer means is composed of two or more spacer parts arranged so that the integrated circuit elements can be seen from the lateral direction perpendicular to the direction in which the first unit and the second unit are stacked. . If the spacer means is constituted by two or more spacer parts dispersedly arranged as in the present invention, the periphery of the integrated circuit element is not completely surrounded by the spacer means. Therefore, for example, when filling a reinforcing filler (underfill agent) that reinforces the mechanical bonding between the circuit board and the integrated circuit element, the peripheral wall of the container is not hindered as in the past, The nozzle can be brought close to the circuit board and the integrated circuit element, and the filling operation is facilitated. Even in the case of a crystal oscillator of a type using wire bonding, if the periphery of the integrated circuit element is not completely surrounded, the bonding operation is facilitated. When the operation becomes easier in this manner, the size of the crystal oscillator can be reduced as compared with the conventional case.

  Further, the two or more spacer parts can be constituted by a plurality of connector chip parts formed by forming a conductive layer on the surface of an electrically insulating base material. In this case, the conductive layer can be used for part of the electrical connection between the integrated circuit element and the crystal resonator. Accordingly, by mounting an inexpensive connector chip component on an inexpensive circuit board in this way, a structure that performs the same function as a conventional ceramic container can be realized at low cost. Further, since the connector chip component can also be used as an electrical connection means, the crystal oscillator can be manufactured at a lower cost than when an expensive ceramic container having a wiring structure is used.

  As such a connector chip component, one in which the base material is made of ceramic and the conductive layer is made of a plating layer can be used. The connector chip component having this structure is already available on the market and can be obtained at a low cost, so that it is effective in reducing the price.

  In addition, when the base material to be used has the shape of a square pole, it is preferable to form the conductive layer continuously on three outer surfaces that are continuous in the circumferential direction of the square pole. When using such a connector chip component as a spacer component, an outer surface on which a conductive layer is formed faces a gap formed between the surface of the circuit board and the second unit. A plurality of spacer parts are preferably arranged. In this way, since the conductive layer is located inside the crystal oscillator, it is difficult to receive external noise.

  In addition, as the connector chip component used as the spacer component, one having a structure in which two conductive layers are arranged along the peripheral portion of one side of the surface of the circuit board can be used. When the connector chip component having such a structure is used, the number of spacer components can be reduced, so that the configuration of the first unit is simplified.

  It is also possible to configure the spacer component from a plurality of bumps. When bumps are used as the spacer parts, the bumps used for electrical connection between the integrated circuit element and the crystal resonator can be used as the spacer parts, so that it is not necessary to prepare special spacer parts. The spacer component may be configured by stacking a plurality of bumps in the facing direction of the first unit and the second unit. The bump is a ball-shaped metal body bonding member formed by a flip chip bonding method.

  According to the present invention, by arranging two or more spacer parts on the surface of the circuit board, a structure corresponding to the container of the first unit can be configured. Further, since the periphery of the integrated circuit element is not completely surrounded by the spacer parts, the assembly work is facilitated. Therefore, it is possible to reduce the size of the crystal oscillator.

  Hereinafter, embodiments of the crystal oscillator according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a first embodiment of a crystal oscillator according to the present invention, and FIG. 2 is a plan view of a first unit 1 described later (a plan view before the second unit 3 is stacked). As shown in both drawings, the crystal oscillator of this example is configured by superposing a first unit 1 and a second unit 3. The first unit 1 has a circuit board 5, an integrated circuit element 7, and spacer means 9. The circuit board 5 is configured by forming a circuit pattern made of plating or the like on the surface of a board body such as a ceramic or glass epoxy board. The circuit pattern of the circuit board 5 includes a plurality of electrodes used for the purpose of soldering a connector chip used as a spacer component, which will be described later, and for the purpose of electrical connection between the integrated circuit element 7 and the second unit. Is also included.

  The integrated circuit element 7 is constituted by an IC chip and is surface-mounted on the circuit board 5. Specifically, the predetermined plurality of electrodes of the integrated circuit element 7 are respectively connected to the predetermined plurality of electrodes on the circuit pattern of the circuit board 5 using the bumps 11. A reinforcing filler (underfill agent) 13 is filled on the circuit board 5 including the gap between the circuit board 5 and the integrated circuit element 7. The underfill agent 13 prevents mechanical damage between the circuit board 5 and the integrated circuit element 7 by preventing the bumps between the circuit board 5 and the integrated circuit element 7 from being damaged. The underfill agent 13 is filled on the circuit board 5 using a nozzle in a fluid state. And after filling, it hardens | cures by heating at 70 degreeC or more.

  The spacer means 9 used in the present embodiment is constituted by a spacer component composed of four connector chip components 15. The four connector chip components 15 are fixed to the electrodes (not shown) provided on the four corners of the peripheral edge of the rectangular circuit board 5 by soldering or using a conductive adhesive.

  FIG. 3 is a perspective view of one connector chip component 15 used in the present embodiment. The connector chip component 15 is configured by forming three conductive layers 19A, 19B, and 19C on a part of the surface of a base material 17. The base material 17 has a quadrangular prism shape made of ceramic, and has six outer surfaces 17a to 17f. The dimension in the height direction in which the outer surface 17 a and the outer surface 17 c of the base material 17 face each other is set larger than the dimension in the height direction of the integrated circuit element 7. Each of the conductive layers 19A, 19B, and 19C is composed of a multilayer plating layer in which solder plating is formed on nickel plating. The conductive layer is continuously formed on the three outer surfaces 17a, 17b, and 17c that are continuous in the circumferential direction of the base material 17 of the quadrangular prism. The conductive layers 19A and 19C are formed on both surfaces of the base material 17 in the thickness direction of the quadrangular prism base material, and the conductive layer 19B is connected to the conductive layers 19A and 19C. The four connector chip components 15 fixed to the four corners of the circuit board 5 have an outer surface 17b on which the conductive layer 19B is formed in a gap formed between the surface of the circuit board 5 and the second unit 3. It is arranged to face. In this way, since the conductive layer 19B is located inside the crystal oscillator, it is difficult to receive external noise. The conductive layers 19C of the four connector chip components 15 are fixed to the electrodes provided on the four corners of the surface of the circuit board 5 by the conductive connection layers 21 made of solder or conductive adhesive. Yes.

  As shown in FIG. 1, the 2nd unit 3 has the metal container structure 23 and the crystal | crystallization blank 25 which comprises a crystal oscillator. The container structure 23 includes a bottom wall portion 27, an upper wall portion 29, a peripheral wall portion of the bottom wall portion 27, and a connecting wall portion 31 that connects the peripheral edge portion of the upper wall portion 29. The corner regions on the back surface of the bottom wall portion 27 are respectively fixed on the four connector chip components 15 by the solder layer 31, and the second unit 3 is superposed on the first unit 1. As described above, since the dimension in the height direction in which the outer surface 17a and the outer surface 17c of the base material 17 face each other is set larger than the dimension in the height direction of the integrated circuit element 7, the second unit is integrated. It is fixed on the four connector chip components 15 with a predetermined gap between the circuit element 7 and the circuit element 7. The bottom surface of the container structure 23 is provided with a pair of electrodes electrically connected to the electrodes of the crystal blank, and these electrodes are electrically connected to at least two of the four connector chips 15 described above. Yes.

  One end of the crystal blank 25 is fixed on the bottom wall portion 27 by a fixing portion 33 made of silver paste so that the crystal blank 25 can vibrate in a region surrounded by the bottom wall portion 27 and the upper wall portion 29. . The bottom wall portion 27 is formed of a circuit board so that the solder layer 31 and the fixed portion 33 of the crystal blank 25 are electrically connected. For this reason, the crystal blank 25 and the integrated circuit element 7 include the fixed portion 33, the circuit pattern of the bottom wall portion 27, the solder layer 31, the conductive layers 19A, 19B, and 19C of the connector chip component 15, the conductive layer 21, and the circuit board 5. The circuit pattern and the bump 11 are electrically connected.

  Further, in this way, the second unit 3 is arranged on the first unit 1 so that the spacer means 9 (four connector chip parts 15) can be connected to the first unit 1 and the second unit 1. The units 3 are arranged in a distributed manner so that a gap formed between the surface of the circuit board 5 and the integrated circuit element 7 can be seen from the lateral direction perpendicular to the direction in which the units 3 are stacked.

  According to the crystal oscillator of this example, the periphery of the integrated circuit element 7 is not completely surrounded by the spacer means. Therefore, when filling the underfill agent 13 using a nozzle, the nozzle can be brought close to the circuit board 5 and the integrated circuit element 7 without being obstructed by the peripheral wall of the container as in the prior art. Work becomes easy. Therefore, even when the first unit is downsized, the underfill agent filling operation is facilitated.

  FIG. 4 is a plan view of the first unit 101 of the crystal oscillator according to the second embodiment of the present invention (a plan view before the second unit is overlaid). The crystal oscillator of this example has the same structure as the crystal oscillator of the first embodiment except for the spacer means. The spacer means 109 used in this example is composed of two connector chip parts 115. The two connector chip components 115 are fixed on the surface of the circuit board 105 along two sides orthogonal to the longitudinal direction of the circuit board 105.

  FIG. 5 is a perspective view of one connector chip component 115. The connector chip component 115 is configured by forming six conductive layers 119A to 119F on a part of the surface of a base material 117 on an elongated prism. The base material 117 has a shape of an elongated quadrangular prism made of ceramic, and has six outer surfaces 117a to 117f. The dimension in the height direction in which the outer surface 117 a and the outer surface 117 c of the base material 117 face each other is set larger than the dimension in the height direction of the integrated circuit element 107. The conductive layers 119A to 119F are formed of a plating layer in the same manner as the conductive layers 19A to 19C described above. Among the conductive layers 119A to 119F, the three conductive layers 119A, 119B, and 119C are formed on three outer surfaces 117a, 117b, and 117c that are continuous in the circumferential direction of the quadrangular prism at one end in the longitudinal direction of the base material 117. It is formed continuously. In addition, among the conductive layers 119A to 119F, the other three conductive layers 119D, 119E, and 119F have three outer surfaces 117a and 117b that are continuous in the circumferential direction of the quadrangular prism at the other end in the longitudinal direction of the base material 117. , 117c. Therefore, the conductive layers 119A and 119D and the conductive layers 119C and 119F are formed on both ends of the quadrangular column of the base material 117. The two connector chip components 115 are arranged so that the outer surface 117b on which the conductive layers 119B and 119E are formed faces a gap formed between the surface of the circuit board 105 and the second unit 103. . Thereby, one connector chip component 115 is arranged so that two conductive layers (119A, 119B, 119C) (119D, 119E, 119F) are arranged along the peripheral edge of the surface of the circuit board 105. . As in this embodiment, when the connector chip 115 provided with conductive layers at both ends is used as the spacer means, the number of spacer parts can be reduced. As a result, the number of parts can be reduced, and an advantage that assembly is facilitated can be obtained.

  FIG. 6 is a plan view of the first unit 201 of the crystal oscillator according to the third embodiment of the present invention (plan view before overlapping the second unit). The crystal oscillator of this example has the same structure as the crystal oscillator of the first embodiment except for the spacer means. The spacer means 209 used in this example is composed of four bumps 215.

  FIG. 7 is a plan view of the first unit 301 of the crystal oscillator according to the fourth embodiment of the present invention (a plan view before the second unit is overlaid). The crystal oscillator of this example has the same structure as the crystal oscillator of the first embodiment except for the integrated circuit element. The integrated circuit element 307 used in this example is electrically connected to the circuit board 305 by wire bonding 308. In the crystal oscillator of this example, an epoxy insulating resin 310 is filled on the circuit board 305 so as to cover the entire integrated circuit element 307 and the wire bonding 308.

  According to the crystal oscillator of this example, since the periphery of the integrated circuit element 307 is not completely surrounded by the spacer means, the possibility that the capillary for supplying wire bonding comes into contact with the spacer means 309 is reduced. Therefore, the wire bonding operation is facilitated. Further, it is not necessary to set the size of the crystal oscillator to the extent that wire bonding can be reliably performed, and the crystal oscillator can be reduced in size.

It is sectional drawing of the crystal oscillator of the 1st Embodiment of this invention. FIG. 3 is a plan view of the first unit of the crystal oscillator according to the first embodiment of the present invention (a plan view before the second unit is overlaid). It is a perspective view of one connector chip component used for the crystal oscillator of the 1st embodiment of the present invention. FIG. 6 is a plan view of a first unit (plan view before stacking a second unit) of a crystal oscillator according to a second embodiment of the present invention. It is a perspective view of one connector chip component used for the crystal oscillator of the 2nd Embodiment of this invention. It is a top view (plan view before superposing the 2nd unit) of the 1st unit of the crystal oscillator of a 3rd embodiment of the present invention. It is a top view (plan view before stacking the 2nd unit) of the 1st unit of the crystal oscillator of a 4th embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st unit 3 2nd unit 5 Circuit board 7 Integrated circuit element 9 Spacer means 13 Reinforcing filler (underfill agent)
15 Connector chip parts 17 Base material 17a-17f External surface 19A, 19B, 19C Conductive layer 25 Crystal resonator (crystal blank)

Claims (7)

A first unit having integrated circuit elements disposed on the surface of the circuit board and spacer means fixed on a peripheral edge of the surface of the circuit board;
A second unit fixed on the spacer means with a predetermined gap between the integrated circuit element and having a crystal resonator inside.
A crystal oscillator in which the integrated circuit element and the crystal resonator are electrically connected,
The spacer means is composed of two or more spacer parts arranged so as to be distributed so that the integrated circuit element can be seen from a lateral direction perpendicular to a direction in which the first unit and the second unit are stacked. A crystal oscillator characterized by The integrated circuit element is surface-mounted on the circuit board,
In order to reinforce the mechanical bond between the circuit board and the integrated circuit element, at least a reinforcing filler having electrical insulation is filled between the circuit board and the integrated circuit element. And
The spacer component is composed of a plurality of connector chip components in which a conductive layer is formed on the surface of an electrically insulating base material, and the conductive layer is electrically connected between the integrated circuit element and the crystal resonator. The crystal oscillator according to claim 1, wherein the crystal oscillator is used as part of a general connection. The integrated circuit element is electrically connected to the circuit board by wire bonding,
The spacer component is composed of a plurality of connector chip components in which a conductive layer is formed on the surface of an electrically insulating base material, and the conductive layer is formed between the integrated circuit element and the electrode of the second unit. The crystal oscillator according to claim 1, wherein the crystal oscillator is used for electrical connection between the two.   The crystal oscillator according to claim 2 or 3, wherein the base material is made of ceramic, and the conductive layer is made of a plated layer. The base material has a quadrangular prism shape, and the conductive layer is continuously formed on three outer surfaces continuous in the circumferential direction of the quadrangular column,
5. The plurality of spacer parts are arranged such that an outer surface on which the conductive layer is formed faces a gap formed between the surface of the circuit board and the second unit. Crystal oscillator. The base has a quadrangular prism shape, and the two conductive layers are formed on both ends of the quadrangular column, and the conductive layers are formed on three outer surfaces that are continuous in the circumferential direction of the quadrangular column. Formed continuously,
The plurality of spacer parts are arranged such that an outer surface on which the conductive layer is formed faces a gap formed between the surface of the circuit board and the second unit,
5. The crystal oscillator according to claim 4, wherein at least one of the spacer components is arranged so that the two conductive layers are arranged along a peripheral edge portion of a surface of the circuit board.   The said spacer component is comprised from several bump, and the said bump is utilized for a part of electrical connection between the said integrated circuit element and the said crystal oscillator. Crystal oscillator.

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