JP2004120658A - Piezoelectric components and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide piezoelectric components with high-productivity, which can make a piezoelectric oscillator vibrate at a desired frequency and a manufacturing method thereof. <P>SOLUTION: In piezoelectric components mounting a piezoelectric oscillator on the top face of a substrate, and having, on the underside of the substrate, an electrode pattern electrically connected to the piezoelectric oscillator, the substrate is laminated via an internal wiring pattern electrically connected to the electrode pattern with a plurality of insulating layers therebetween, and is formed by providing a through-hole at the insulating layers on the internal wiring pattern. The piezoelectric oscillator and the internal wiring pattern are electrically connected via conductive adhesive a part of which is filled in the through-hole. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to, for example, a piezoelectric component used for generating a reference signal of a portable communication device or the like, in which a piezoelectric oscillator such as a quartz oscillator is mounted on a base such as a ceramic package, and a method of manufacturing the same. It is.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, piezoelectric components have been used to generate reference signals for electronic devices such as portable communication devices.
[0003]
As such a conventional piezoelectric component, for example, as shown in FIG. 4, a seal ring 57 is attached on a base 51 made of a ceramic material or the like, and a piezoelectric member is disposed on the upper surface of the base 51 located inside the seal ring 57. A quartz oscillator 52 as an oscillator is mounted so as to be held only at one end thereof, and a metal lid 53 is placed and fixed on the seal ring 57 to hermetically seal the quartz oscillator 52. A structure having a stopped structure is known (for example, see Patent Document 1).
[0004]
A connection pad 55 electrically connected to an electrode pad (not shown) of the crystal unit 52 is provided on an upper surface of the base 51, and is electrically connected to the connection pad 55 on a lower surface of the base 51. An electrode pattern 59 is attached, and the connection pad 55 and the electrode pattern 59 are electrically connected to each other via a via-hole conductor 56 and an internal wiring pattern 58 provided inside the base 51.
[0005]
The electrical connection between the electrode pads of the crystal unit 52 and the connection pads 55 is performed by adding and mixing a predetermined amount of conductive particles made of Ag or the like in a resin material made of a silicon resin, a polyimide resin, or the like. The conductive adhesive 54 is used. The conductive adhesive 54 is adjusted to a predetermined viscosity to form a paste, and the paste is applied onto the connection pads 55 on the upper surface of the base by a conventionally known dispenser method or the like. The quartz oscillator 52 is placed on the conductive adhesive 54, and is heated and cured at a high temperature, whereby the quartz oscillator 52 is mounted on the base 51.
[0006]
[Patent Document 1]
JP-A-2002-111435 (page 5-6, FIG. 2)
[0007]
[Problems to be solved by the invention]
However, in the above-described conventional piezoelectric component, when the quartz oscillator 52 is mounted on the substrate 51, the step of placing the quartz oscillator 52 on the conductive adhesive 54 or the conductive adhesive 54 is thermally cured. In a process or the like, a part of the conductive adhesive 54 may flow down from above the connection pad 55 as shown in FIGS. In this case, with the flow of the conductive adhesive 54, the quartz oscillator 52 placed thereon is greatly inclined, and the other end of the quartz oscillator 52 contacts the lower surface of the lid 53 and the upper surface of the base 51. As a result, there is a disadvantage that it is impossible to oscillate the crystal oscillator 52 at a predetermined oscillation frequency.
[0008]
The present invention has been made in view of the above-described drawbacks, and has as its object to provide a high-productivity piezoelectric component capable of vibrating a piezoelectric vibrator at a desired frequency, and a method of manufacturing the same.
[0009]
[Means for Solving the Problems]
The piezoelectric component of the present invention is a piezoelectric component having a piezoelectric vibrator mounted on an upper surface of a base and having an electrode pattern electrically connected to the piezoelectric vibrator on a lower surface of the base. The insulating layer is formed by laminating an insulating layer therebetween via an internal wiring pattern electrically connected to the electrode pattern, and providing a through hole in the insulating layer located between the internal wiring pattern and the upper surface of the base. Wherein the piezoelectric vibrator and the internal wiring pattern are filled in the through hole, and a part of the piezoelectric vibrator and the internal wiring pattern are electrically connected via a conductive adhesive projecting from the upper surface of the base. is there.
[0010]
The method for manufacturing a piezoelectric component according to the present invention may further include forming a base by laminating a plurality of insulating layers with an internal wiring pattern interposed therebetween, and forming an insulating layer between the internal wiring pattern and the upper surface of the base. Forming a through-hole, an electrode pattern electrically connected to the internal wiring pattern on the lower surface of the base, and applying a paste-like conductive adhesive in the through-hole; Filling the piezoelectric vibrator so as to protrude upward, placing the piezoelectric vibrator on the upper surface of the base such that the protruding portion of the conductive adhesive adheres to the connection electrode of the piezoelectric vibrator, and By heat-treating the adhesive and simultaneously curing the conductive adhesive in the through-hole and the conductive adhesive attached to the connection electrode of the piezoelectric vibrator, the piezoelectric vibrator in the through-hole has the conductive adhesive in the through-hole. Through the internal wiring It is characterized in that a step of turn and electrically connected.
[0011]
According to the present invention, a plurality of insulating layers are laminated via an internal wiring pattern therebetween, and a base provided with a through hole in the insulating layer on the internal wiring pattern is formed, and a piezoelectric member mounted on the base is formed. Since the vibrator and the internal wiring pattern are electrically connected to each other through a conductive adhesive that is filled in the through hole and partially protrudes from the upper surface of the base, the piezoelectric vibrator is mounted on the base. When mounting on a conductive adhesive, part of the conductive adhesive hardly flows sideways during the process of placing the piezoelectric vibrator on the conductive adhesive or the process of thermally curing the conductive adhesive, During the step, the orientation of the piezoelectric vibrator placed on the conductive adhesive can be maintained in a predetermined direction. Therefore, the other end of the piezoelectric vibrator is always kept in non-contact with the base or the lid, and the piezoelectric vibrator can be vibrated at a predetermined oscillation frequency, and the productivity of the piezoelectric component can be improved. It becomes.
[0012]
Further, according to the present invention, since the piezoelectric vibrator is directly connected to the conductive adhesive filled in the through hole of the base, the upper surface of the base is provided with the piezoelectric vibrator. There is no need to separately form connection pads or the like for connection, and the manufacturing process of the piezoelectric component can be simplified. Therefore, this also makes it possible to improve the productivity of the piezoelectric component.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
[0014]
FIG. 1 is a cross-sectional view showing an embodiment in which the piezoelectric component of the present invention is applied to a crystal oscillator. FIG. 2 is an enlarged cross-sectional view of a main part of FIG. 1. A crystal oscillator 10 shown in FIG. At the same time, the crystal oscillator 14 as a piezoelectric oscillator is mounted on the upper surface of the base 11 located inside the seal ring 18 in a form (single holding type) holding only one end thereof. Further, the lid 12 is placed and fixed on the seal ring 18 and the crystal unit 14 is hermetically sealed in a region surrounded by the upper surface of the base, the inner surface of the seal ring, and the lower surface of the lid. .
[0015]
The base 11 is formed by laminating a plurality of insulating layers made of a ceramic material or the like with an internal wiring pattern 15 or the like interposed therebetween. An electrode pattern 16 such as an input / output electrode and a ground electrode, which are electrically connected to each other, is attached, and this electrode pattern 16 functions as a connection terminal for connecting the piezoelectric component to an external circuit board such as a motherboard.
[0016]
The base 11 has a through hole 13 in an insulating layer located between the internal wiring pattern 15 provided therein and the upper surface of the base 11. The through-hole 13 is buried and filled with a conductive adhesive 17 described later, and the internal wiring pattern 15 and the crystal unit 14 are electrically connected via the conductive adhesive 17. You.
[0017]
The quartz oscillator 14 mounted on the base 11 is obtained by cutting a quartz plate formed by a conventionally known hydrothermal synthesis method or the like along a predetermined crystal axis to obtain a strip-shaped quartz piece. It has a structure in which a mask of a predetermined shape is arranged on the main surface, and a pair of excitation electrodes is attached and formed using means such as vapor deposition or sputtering.
[0018]
When a predetermined voltage is applied between a pair of excitation electrodes, the crystal resonator 14 generates slip vibration at a predetermined frequency, and serves as a resonator for generating a reference signal such as a clock signal. Function.
[0019]
The electrical connection between the crystal unit 14 and the internal wiring pattern 15 is provided via a conductive adhesive 17 which is filled in the through hole 13 and partially protrudes from the upper surface of the base. It is done.
[0020]
The conductive adhesive 17 is obtained by adding and mixing a predetermined amount of conductive particles made of Ag or the like in a resin material made of a silicon resin, a polyimide resin, or the like, and joining the internal particles to the internal wiring pattern 15 at the lower end thereof. The projection provided at the upper end portion is joined to an electrode pad (not shown) derived from the excitation electrode of the quartz oscillator 14, thereby electrically connecting the quartz oscillator 14 and the internal wiring pattern 15. ing.
[0021]
On the other hand, a seal ring 18 attached to the upper surface of the base 11 is disposed outside the above-described quartz oscillator 14 so as to surround the quartz oscillator 14, and is placed on the upper surface thereof. The quartz oscillator 14 is hermetically sealed in a region surrounded by the upper surface of the base, the inner surface of the seal ring, and the lower surface of the lid by performing resistance welding (seam welding) of the lid 12 to the upper surface of the seal ring 18. .
[0022]
The seal ring 18 and the lid 12 are formed by processing a metal such as 42 alloy, Kovar, phosphor bronze or the like into a predetermined shape by a conventionally known metal working method. For this purpose, Ni plating, Au plating, and the like, which are necessary for this purpose, are applied.
[0023]
Further, in order to resistance-weld the lid 12 to the seal ring 18, the lid 12 is placed on the seal ring 18, and then, while pressing the roller electrode of the resistance welding device against each side of the lid 12, This is performed by passing a predetermined current between the lid 11 and the lid 12 and melting the welding material between the base 11 and the lid 12 by Joule heat generated by energization.
[0024]
Next, a method for mounting the crystal unit 14 of the crystal oscillator 10 on the base 11 will be described with reference to FIG.
(Step 1) First, as shown in FIG. 3A, the base 11 is formed by laminating a plurality of insulating layers via the internal wiring pattern 15 therebetween, and the internal wiring pattern 15 and the upper surface of the base 11 are formed. A through-hole 13 is formed in the insulating layer located between them, and an electrode pattern 16 electrically connected to the internal wiring pattern 15 is formed on the lower surface of the base 11.
[0025]
When the insulating layer is made of a ceramic material, the base 11 forms an internal wiring pattern 15 and an electrode pattern 16 on the main surface of a ceramic green sheet obtained by adding and mixing an appropriate organic solvent or the like to powder of a ceramic raw material. A conventional conductive paste is printed in a predetermined pattern by screen printing or the like, and a plurality of layers are laminated and then press-formed. Thereafter, the laminated body is fired at a high temperature and processed to form an outer shape. You. The through-hole 13 provided in the base 11 is formed by a conventionally known laser processing, punching, or the like, and the inner surface of the obtained through-hole 13 is further subjected to Ni plating, Au plating, or the like.
[0026]
(Step 2) Next, as shown in FIG. 3B, the paste-like conductive adhesive 17 'is filled in the through holes.
The filling operation of the paste-like conductive adhesive 17 ′ is performed by employing a conventionally well-known dispenser method or the like. The conductive adhesive 17 ′ has a lower portion exposed in the through-hole 13 in the internal wiring pattern 15. , And a portion thereof is filled in the through-hole 13 so as to protrude above the upper surface of the base 11.
[0027]
(Step 3) Subsequently, as shown in FIG. 3 (c), the projection of the conductive adhesive 17 'is attached to a connection electrode (not shown) of the crystal resonator 14, and the crystal resonator 14 is The conductive adhesive 17 ′ is placed on the upper surface of the base 11, and then the conductive adhesive 17 ′ is heat-treated, so that the conductive adhesive 17 ′ in the through-hole 13 and the conductive adhesive adhered to the connection electrode of the crystal unit 14. 17 ′ is thermally cured at the same time, whereby the quartz oscillator 14 is electrically connected to the internal wiring pattern inside the base via the conductive adhesive 17 in the through hole 13.
[0028]
When the quartz oscillator 14 is mounted on the base 11 by the above-described steps, since a part of the conductive adhesive 17 ′ is filled in the through hole 13, the crystal is placed on the conductive adhesive 17 ′. During the step of mounting the vibrator 14 (step 1) and the step of thermally curing the conductive adhesive 17 '(step 3), a portion of the conductive adhesive 17' hardly flows laterally. During these steps, the orientation of the quartz oscillator 14 placed on the conductive adhesive 17 ′ can be maintained in a predetermined direction (a method substantially parallel to the upper surface of the base 11). Therefore, the other end side of the crystal unit 14 is kept in non-contact with the upper surface of the base 11 and the lower surface of the lid 12 attached to the seal ring 18 in a later step. As a result, the quartz oscillator 14 of the piezoelectric component obtained as described above can be vibrated at a predetermined oscillation frequency, and the productivity of the piezoelectric component can be improved.
[0029]
Further, in the above-described manufacturing method of the present embodiment, since the quartz oscillator 14 is directly connected to the conductive adhesive 17 filled in the through hole 13 of the base 11, There is no need to form a separate connection pad or the like on the upper surface for connection with the crystal unit 14, so that the manufacturing process of the piezoelectric component can be simplified. Therefore, this also makes it possible to improve the productivity of the piezoelectric component.
[0030]
Note that the present invention is not limited to the above-described embodiment, and various changes, improvements, and the like can be made without departing from the gist of the present invention.
[0031]
For example, although the quartz oscillator 14 is used as the piezoelectric vibrator in the above-described embodiment, the present invention may be applied to a case where another piezoelectric vibrator such as a SAW filter is used as the piezoelectric vibrator instead. Is applicable.
[0032]
In the above-described embodiment, the quartz oscillator 14 is hermetically sealed by the lid 12 and the seal ring 18. However, for example, when another piezoelectric oscillator such as a SAW filter is used as the piezoelectric oscillator. The piezoelectric vibrator may be hermetically sealed using a sealing resin made of epoxy resin or the like.
[0033]
Further, in the above-described embodiment, a predetermined concave portion is provided on the lower surface of the base 11 and in a region where the electrode pattern 16 does not exist. It may be stored.
[0034]
Further, in the above-described embodiment, the base 11 is formed by a conventionally well-known ceramic green sheet laminating method. Alternatively, the base 11 may be formed by a press molding method using ceramic powder. I do not care.
[0035]
Furthermore, in the above-described embodiment, when filling the paste-like conductive adhesive 17 ′ into the through-hole 13 of the base 11, the conductive adhesive 17 is applied and filled into the through-hole 13 in two or more times. Needless to say, this is acceptable.
[0036]
【The invention's effect】
According to the present invention, a plurality of insulating layers are laminated via an internal wiring pattern therebetween, and a base provided with a through hole in the insulating layer on the internal wiring pattern is formed, and a piezoelectric member mounted on the base is formed. Since the vibrator and the internal wiring pattern are electrically connected via a conductive adhesive filled in the through hole and partially protruding from the upper surface of the base, the piezoelectric vibrator is mounted on the base. When mounting on a conductive adhesive, part of the conductive adhesive hardly flows sideways during the process of placing the piezoelectric vibrator on the conductive adhesive or the process of thermally curing the conductive adhesive, During the step, the orientation of the piezoelectric vibrator placed on the conductive adhesive can be maintained in a predetermined direction. Therefore, the other end of the piezoelectric vibrator is always kept in non-contact with the base or the lid, and the piezoelectric vibrator can be vibrated at a predetermined oscillation frequency, and the productivity of the piezoelectric component can be improved. It becomes.
[0037]
Further, according to the present invention, since the piezoelectric vibrator is directly connected to the conductive adhesive filled in the through hole of the base, the upper surface of the base is provided with the piezoelectric vibrator. There is no need to separately form connection pads or the like for connection, and the manufacturing process of the piezoelectric component can be simplified. Therefore, this also makes it possible to improve the productivity of the piezoelectric component.
[Brief description of the drawings]
FIG. 1 is a sectional view of a piezoelectric component according to an embodiment of the present invention.
FIG. 2 is an enlarged sectional view of a main part of the piezoelectric component of FIG.
3 (a) to 3 (c) are cross-sectional views for each process for explaining a method of manufacturing the piezoelectric component of FIG.
FIG. 4 is a sectional view of a conventional piezoelectric component.
FIGS. 5A and 5B are enlarged cross-sectional views for explaining a problem of a conventional example.
[Explanation of symbols]
10 Piezoelectric components (crystal oscillators)
DESCRIPTION OF SYMBOLS 11 ... Base 12 ... Lid 13 ... Through-hole 14 ... Piezoelectric oscillator (quartz oscillator)
15 ... internal wiring pattern 16 ... electrode pattern 17 ... conductive adhesive 17 '... paste-like conductive adhesive 18 ... seal ring

Claims (2)

A piezoelectric component having a piezoelectric vibrator mounted on an upper surface of a base and having an electrode pattern electrically connected to the piezoelectric vibrator on a lower surface of the base,
The base laminates a plurality of insulating layers via an internal wiring pattern electrically connected to the electrode pattern therebetween, and also has a through hole in the insulating layer located between the internal wiring pattern and the upper surface of the base. The piezoelectric vibrator and the internal wiring pattern are filled in the through-holes, and are partially electrically connected via a conductive adhesive projecting from the upper surface of the base. A piezoelectric component. A base is formed by laminating a plurality of insulating layers via an internal wiring pattern therebetween, and a through hole is formed in the insulating layer located between the internal wiring pattern and the upper surface of the base, and the internal hole is formed in the lower surface of the base. Forming an electrode pattern electrically connected to the wiring pattern;
A step of filling a paste-like conductive adhesive in the through-hole so that a part thereof protrudes above the upper surface of the base,
A step of mounting the piezoelectric vibrator on the upper surface of the base such that the protrusion of the conductive adhesive adheres to the connection electrode of the piezoelectric vibrator,
By heat-treating the conductive adhesive and simultaneously curing the conductive adhesive in the through-hole and the conductive adhesive attached to the connection electrode of the piezoelectric vibrator, the piezoelectric vibrator is electrically conductive in the through-hole. Electrically connecting to the internal wiring pattern via an adhesive.

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