TW201543812A - Crystal vibrator and manufacturing method thereof - Google Patents

Abstract

The disclosure provides a crystal vibrator and a manufacturing method thereof, wherein the crystal vibrator is equipped with a chip on a main surface of a ceramic substrate which is rectangular in a plan view. The crystal vibrator includes: supporting electrodes of the chip, formed in a main surface; penetration ends, formed in cutout portions that are disposed on four corners of the substrate; a tape-shaped insulation film, formed in an inner side of an outer peripheral edge of the ceramic substrate; a metal cover, covering the chip and hermetically sealing a inner portion. The crystal vibrator may form a conductive member on portions that electrically connect two of the penetration ends that used as ground ends among the penetration ends, on portions that the insulation film is not formed, and on positions that fix and seal the metal cover, so as to electrically connect the penetration ends and the metal cover via the conductive member. Therefore, a mal-function action of the circuit may be prevented.

Description

Crystal oscillator and crystal oscillator manufacturing method

The present invention relates to a method for manufacturing a crystal oscillator and a crystal resonator, and more particularly to a method of bonding a metal sheet to a metal by bonding a metal cover with a conductive resin or the like on a base formed of an insulator such as ceramic (ceramic). In the crystal resonator in the cover, a ground (GND) terminal that is electrically connected to the outer bottom surface of the susceptor and a conductor of the metal cover are provided on the sealing surface to prevent capacitance variation and noise near the circuit of the crystal resonator (noise) A method of manufacturing a crystal oscillator and a crystal oscillator that cause abnormal operation of the circuit.

In the conventional crystal oscillator, as shown in FIG. 6 and FIG. 7, the support electrode lower layer portion 3a is integrally formed by AgPd alloy (silver-palladium alloy) on the surface 1b of the rectangular ceramic base 1 in plan view. And the connection terminal 2a is formed in a castle-shaped structure (notch portion) formed by a wall surface of a through hole (through hole) 1a formed by a sheet-like ceramic blank at the four corners of the ceramic base 1 There are a through terminal 2b formed of AgPd and a through terminal 2c.

Further, a support electrode lower layer portion 3a is formed on the surface 1b of the ceramic base 1, The support electrode lower layer portion 3a is formed in a lower layer connected to the through terminal 2c to hold the support electrode 3b of the crystal piece 5, and is formed of an AgPd alloy.

Further, on the upper surface of the support electrode lower layer portion 3a, the support electrode 3b which is bonded and held by the conductive resin 7 by the conductive resin 7 is formed by AgPd, and is further inside the outer edge portion of the upper surface of the ceramic base 1. A strip-shaped insulating film 10 is formed which does not electrically short the metal cap 6 and the supporting electrode 3b of the crystal piece 5.

Then, the metal cover 6 is placed on the upper surface of the insulating film 10, and is bonded to the insulating film 10 by a suitable sealing material such as a low-melting glass or a thermosetting resin, thereby sealing the crystal piece 5 in the metal cover 6.

Further, generally, four mounting terminals 4 are provided at the four corners of the outer bottom surface 1c of the ceramic base 1, and an electrode pattern connected to the mounting terminals 4 of the respective through terminals 2b and 2c is formed of an AgPd alloy. Here, the mounting terminal 4 connected to the through terminal 2c is an electrode to which a voltage is applied, and the mounting terminal 4 connected to the through terminal 2b is a ground electrode connected to a ground level (see Patent Document 1 and Patent Document 2).

(Patent Document 1: Japanese Patent Laid-Open Publication No. 2013-70357

Patent Document 2: Japanese Patent Laid-Open Publication No. 2011-211681

Patent Document 3: Japanese Patent Laid-Open Publication No. 2009-105628

In a pedestal of a resin sealing package which is hermetically sealed to a susceptor formed of an insulator of the ceramic material by a conductive resin, a surface (sealing surface) which seals the metal cap resin , connecting the crystal piece to the external terminal The electrical conductors are disposed on the same surface. Therefore, if the metal cap resin is sealed with a conductive resin, the crystal supporting terminal is electrically short-circuited with the metal cap, and therefore, an insulating layer formed of a glass material or the like is formed on the sealing surface.

Further, in the case where a crystal resonator of four external terminals is provided on the outer bottom surface of the susceptor, two terminals (NC terminals) that are not connected to the crystal piece are not disposed on the same surface as the sealing surface.

However, in the case where these terminals are disposed on the same surface, as described above, since the insulating layer is formed on the upper surface of the susceptor, even if the metal cover is fixed by using a conductive resin during sealing, the metal cover cannot be electrically charged. Since the connection is made, it is impossible to prevent abnormal operation of the circuit due to a change in capacitance in the vicinity of the circuit of the crystal oscillator, noise generation, or the like.

In such a conventional crystal oscillator, since the metal cover is not electrically connected to the ground terminal, the metal cover is electrically identical to the electrostatic capacitance (C) or the antenna if viewed from the circuit side on which the crystal oscillator is mounted. The state plays a role.

In the crystal resonator using such a resin-sealed susceptor, if a crystal oscillator is mounted on a circuit board, it can be used, for example, if there is a case where a human hand approaches a crystal oscillator to cause a change in capacitance or noise in the vicinity of the circuit. The circuit formed on the circuit board does not operate normally and functions.

Therefore, in order to eliminate such a failure, in a Seam Sealing type crystal oscillator, a cover (lid) is electrically connected to a ground provided on an outer bottom surface of the ceramic base via a seal ring. Terminal (refer to Patent Document 3).

The present invention has been made to solve such a problem, and relates to a crystal oscillator in which a crystal piece is mounted on a main surface of a rectangular ceramic sub-frame, and the crystal oscillator includes: a supporting electrode of the crystal piece, Formed on the main surface; a through-terminal formed in a notch portion provided at four corners of the ceramic base; a strip-shaped insulating film formed on an inner side of an outer peripheral portion of the ceramic base; and a metal cover covering The crystal piece is hermetically sealed inside; the crystal oscillator is characterized in that at least one of the through terminals that function as a ground terminal that can be electrically connected to the through terminal and that does not form the insulating film A conductor is disposed on the sealing surface of the portion to which the metal cover is fixed and sealed, and the ground terminal is electrically connected to the metal cover via the conductor.

Further, the present invention is characterized in that the conductor is formed as a conductive film connected to the two through terminals.

Moreover, the present invention relates to a method of manufacturing a crystal oscillator, which is characterized in that a conductor is formed at a portion where the insulating film is not formed and at a portion where the metal cap is fixed and sealed. .

According to the crystal resonator of the present invention, it is possible to prevent abnormal operation of the circuit due to capacitance change and noise generation in the vicinity of the circuit formed in the crystal resonator.

1‧‧‧Ceramic base

1a‧‧‧through hole

1b‧‧‧ surface

1c‧‧‧Outer bottom

2a‧‧‧Connecting terminal

2b‧‧‧through terminal

2c‧‧‧through terminal

3a‧‧‧Support electrode lower layer

3b‧‧‧Support electrode

4‧‧‧Installation terminal

5‧‧‧Crystal

6‧‧‧Metal cover

6a‧‧‧Flange

6b‧‧‧ thermosetting resin

6c‧‧‧ Conductive adhesive

7‧‧‧ Conductive resin

10‧‧‧Insulation film

11‧‧‧Electric conductor

S‧‧‧Sheet ceramic substrate

B‧‧‧Cut line

#1#3‧‧‧Connecting terminal

#2#4‧‧‧ Grounding terminal

Fig. 1 is a connection diagram of a terminal pad applied to a crystal resonator as an embodiment of a crystal resonator of the present invention.

2 is a plan view of a ceramic susceptor forming a supporting electrode pattern of the crystal resonator of the present invention.

3(a) and 3(b) show a partial cross section of an NC terminal portion of a conventional example and a crystal resonator of the present invention, and Fig. 3(a) shows an II-II arrow of the NC terminal portion of the conventional example shown in Fig. 7. A partial cross section of the viewing portion, and Fig. 3(b) shows a partial cross section of the II arrow portion of the NC terminal portion of the present invention shown in Fig. 2 .

Fig. 4 is a flow chart showing a method of manufacturing a crystal resonator of the present invention.

5 is a plan view of a sheet-like ceramic substrate in which a through hole and a break line are formed in a sheet-like ceramic blank used in the production of the crystal resonator of the present invention.

Fig. 6 is a longitudinal sectional view showing a conventional crystal resonator.

Fig. 7 is a plan view showing a ceramic susceptor in which a supporting electrode pattern is formed in the conventional crystal resonator shown in Fig. 6.

Hereinafter, an embodiment of the crystal resonator of the present invention will be described based on the drawings.

(Example of crystal oscillator)

First, FIG. 1 shows a connection diagram of a terminal pad applied to a crystal resonator of the present invention. As shown in FIG. 1, among the crystal oscillators in which four mounting terminals are provided on the outer bottom surface of the susceptor, among the four mounting terminals Two mounting terminals as connection terminals #1 The connection terminal #3 is electrically connected to the electrode formed on the crystal piece. However, although the remaining two mounting terminals are formed with terminals, they are not connected to the crystal piece and function as the ground terminal #2 and the connection terminal #4.

In the crystal resonator of the present invention, a conductor is provided at a position connected to the two ground terminals #2 and #4, and a metal cover that hermetically seals the crystal piece is bonded to a conductor provided on the sealing surface. The metal cover is electrically connected to the ground terminals #2 and #4 by a conductive resin.

Similarly to the conventional crystal resonator shown in FIG. 6 and FIG. 7, the crystal resonator of the present invention integrally forms the support electrode lower layer portion 3a and the connection terminal 2a with AgPd alloy on the surface 1b of the rectangular ceramic base 1 in plan view. The four corners of the ceramic base 1 are formed into a castle-shaped structure (notch portion) formed by dividing a through hole (through hole) 1a formed in a sheet-like ceramic blank into four portions, and the notch portion is respectively formed in the notch portion. A through terminal 2b formed of AgPd and a through terminal 2c are formed.

Further, a support electrode lower layer portion 3a is formed on the surface 1b of the ceramic base 1, and the support electrode lower layer portion 3a is formed on the lower layer of the support electrode 3b which is connected to the through terminal 2c to hold the crystal piece 5, and is formed of an AgPd alloy.

Further, on the upper surface of the support electrode lower layer portion 3a, the support electrode 3b joined by the conductive resin 7 and holding the crystal piece 5 is formed by AgPd, and a strip shape is formed on the inner side of the outer peripheral portion of the upper surface of the ceramic base 1. The insulating film 10.

Then, a metal cover 6 is bonded to the upper surface of the insulating film 10 via a low-melting glass containing a thermosetting conductive resin or a high-purity Pb (lead), and the crystal piece 5 is hermetically sealed in the metal lid 6.

Here, the melting point of the low-melting glass is usually 600 to 700 ° C, but the melting point changes depending on the additive. The low-melting glass used in the present invention has a melting point of 320 ° C by adding lead (Pb). Therefore, if the amount of addition is small, the low-melting glass is similar to the insulator, but the low-melting glass used in the present invention contains a large amount of lead (Pb), and thus becomes a conductor.

Further, four mounting terminals 4 are provided at the four corners of the outer bottom surface 1c of the ceramic base 1, and the electrode patterns of the mounting terminals 4 connected to the respective through terminals 2b and the through terminals 2c are formed of an AgPd alloy. Here, the mounting terminal 4 connected to the through terminal 2c functioning as the connection terminal #1 and the connection terminal #3 is an electrode to which a voltage is applied, and the mounting terminal 4 connected to the through terminal 2b is connected to the ground plane. The ground terminal works.

In the crystal resonator of the present invention, particularly as shown in FIG. 2 and FIG. 3(b) of FIG. 2, the two through-terminals 2b functioning as ground terminals are electrically connected to these through-holes. The position of the terminal 2b is respectively provided with a conductor 11 formed of a suitable conductive material, and the bonding metal is adhered to the upper surface of the two conductors 11 and the insulating film 10 by using a conductive adhesive or a low-melting glass 6c. The open end face of the flange 6a of the cover 6.

Here, the conductor 11 may be electrically connected to the two through terminals that function as ground terminals, and may have any shape. For example, it may be formed at a position where the conductor 11 is electrically connected to the through-terminal 2b as a conductive film, or may be formed from a through-electrode formed on the ceramic susceptor 1 or the like from the through-terminal as shown by a chain line in FIG. 2 . The spaced apart locations of 2b are formed and electrically connected to the metal cover 6. Here, the material of the electrical conductor 11 The material may be a material containing a material having high conductivity, for example, an inexpensive material such as copper or a conductive polymer material. No need to use expensive materials such as gold and silver.

As described above, the conductor 11 is joined to the metal cover 6 via the conductive adhesive or the low-melting glass 6c, and the two through terminals 2b functioning as the ground terminals are electrically connected to the metal cover 6 to prevent the vicinity of the circuit due to the crystal resonator. Abnormal operation of the circuit caused by capacitance change and noise generation. As a result, the customer can ensure good electrical characteristics after mounting the crystal oscillator on the circuit board.

On the other hand, in the crystal resonator of the conventional example shown in FIG. 7 , even when the metal cover 6 is bonded to the ceramic base 1 , a conductive resin is used. As described above, since the insulating layer is formed on the sealing surface, the metal is formed. The cover 6 is not electrically connected to the ground terminal 2b.

(Example of a method of manufacturing a crystal oscillator)

Next, a method of manufacturing the crystal resonator of the present invention will be described based on FIGS. 4 and 5.

As shown in FIG. 4, in the first step (S1) of the method for producing a crystal resonator of the present invention, first, a sheet-like ceramic blank which is a sheet-like ceramic substrate S from which a plurality of ceramic susceptors 1 can be produced is formed. Next, the through hole 1a is formed at a position corresponding to the four corner portions of the respective ceramic susceptors 1 as shown in FIG. 5, and the cut line (break line) B is formed at a position where the four corner portions are joined, and the sheet ceramic is fired. The sheet-like ceramic substrate B was obtained from the blank.

In the second step (S2), AgPd is printed using screen masks on the circuit pattern forming faces of the respective ceramic susceptors 1 of the sheet-like ceramic substrate B. A metal paste of the alloy forms a circuit pattern.

In the third step (S3), a heat-resistant resin or a glass paste is used around the circuit pattern formed in each of the ceramic susceptors 1, and a screen is used in addition to a portion where a conductor is to be provided in the next step. The insulating film 10 is formed by molding.

In the fourth step (S4), the conductor 11 formed of a suitable conductive material is provided at a portion where the insulating film 10 is not formed in the previous step. Usually, a metal paste is printed using a screen mask to form a conductive film.

In the fifth step (S5), the support electrode 3b made of AgPd is formed on the circuit formation surface of each ceramic susceptor 1 on which the circuit pattern is formed.

In the sixth step (S6), the crystal piece 5 is fixed by the conductive adhesive 7 on the upper surface of the support electrode 3b, and electrically and mechanically connected to the support electrode 3b.

In the seventh step (S7), the vibration frequency of the crystal piece 5 of each of the ceramic susceptors 1 mounted on the sheet-like ceramic substrate is measured and adjusted in accordance with the mass load effect.

In the eighth step (S8), the opening end faces of the flanges 6a of the metal cover 6 are joined to the insulating film 10 and the conductor 11 corresponding to the respective ceramic bases 1 using a conductive adhesive or a low-melting glass 6c. The crystal piece 5 is hermetically sealed in the metal lid 6.

In the ninth step (S9), each of the crystal oscillators is obtained by dividing the sheet-like ceramic substrate along the cut line (break line).

#1#3‧‧‧Connecting terminal

#2#4‧‧‧ Grounding terminal

Claims (3)

a crystal oscillator in which a crystal piece is mounted on a main surface of a rectangular ceramic base in plan view, the crystal oscillator comprising: a supporting electrode of the crystal piece formed on the main surface; and a through-terminal a notch portion formed at four corners of the ceramic base; a strip-shaped insulating film formed on an inner side of an outer peripheral portion of the ceramic base; and a metal cover covering the crystal piece and hermetically sealing the inside The crystal oscillator can be electrically connected to at least one of the through terminals that function as a ground terminal in the through terminal, and is fixed and sealed at a portion where the insulating film is not formed and for the metal cover A conductor is provided on the sealing surface, and the ground terminal and the metal cover are electrically connected via the conductor. The crystal resonator according to claim 1, wherein the conductor is formed as a conductive film connected to the through terminal. A method for producing a crystal oscillator, which is a method for producing a crystal resonator according to the first or second aspect of the invention, wherein the method of manufacturing the crystal resonator is characterized in that the insulating film is not formed The electric conductor is formed at a portion where the metal cover is fixed and sealed.