JP2000031742A - Piezoelectric oscillator, molding die for piezoelectric oscillator and manufacture of piezoelectric oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a small-sized and thin- piezoelectric oscillator by which the mount workability is enhanced. SOLUTION: A lead frame 5 to which an oscillation circuit is integrated is inserted to a lead frame groove 2b of a lower molding die 2, and the oscillation circuit including part of the lead frame 5 is positioned and inserted to a cavity formed by an upper molding die 1 and the lower molding die 2, the dies are tightened and a resin is molded in the molding die for the piezoelectric oscillator. A gate 2d through which the resin is injected is provided to a side face of a metallic sealing pipe of a crystal vibrator 4, an overflow gate 2e is provided to at least either of a lead terminal side and a tip side of the crystal vibrator 4 orthogonal to the gate 2s and a dummy cavity 2f is provided to the outside of the overflow gate 2e.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric oscillator, a mold for forming a piezoelectric oscillator, and a method for manufacturing a piezoelectric oscillator. More particularly, the present invention relates to a method for manufacturing a small and thin piezoelectric oscillator with improved workability in mounting.

[0002]

2. Description of the Related Art In a conventional piezoelectric oscillator, an oscillation circuit is formed by soldering a lead terminal of a quartz oscillator to an electronic circuit on which an IC is mounted. As the mounting density of circuits has increased, it has become extremely difficult to perform the conventional soldering of a quartz oscillator. In recent years, the workability and reliability of mounting have been improved by using an oscillation circuit as a piezoelectric oscillator that can be surface-mounted by resin molding.

[0003] As a method of fixing a quartz oscillator substantially at the center of a cavity of an injection mold at the time of resin molding, projections are provided on a bottom surface of an upper cavity and a bottom surface of a lower cavity, and a side surface of the quartz oscillator is closed at the time of mold clamping. Japanese Patent Application Laid-Open No. 2-97109 discloses a technique for positioning by contacting the tip of the projection.

In Japanese Patent Application Laid-Open No. 1-262115, a slide pin or slide piece (hereinafter referred to as a slide part) which can be inserted into and retracted from a cavity at the time of mold clamping is projected into the cavity by a spring force or air pressure and inserted. There is disclosed a mold structure in which positioning is performed by contacting an IC chip, and when the filling of the resin is completed, the slide component is lowered to the bottom surfaces of the upper cavity and the lower cavity by the resin pressure in the cavity.

Further, Japanese Utility Model Registration No. 2543874 discloses a mold structure in which the thickness of a quartz oscillator main body is equal to the thickness of a resin mold, and a method in which a hole is formed on one side corresponding to a quartz oscillator mold portion of a mold resin to face the opposite side. Discloses a mold structure in which a quartz oscillator main body and a mold surface are in contact with each other.

A thermosetting resin (epoxy resin) for sealing, which has a low viscosity at the time of molding, is generally used for the above resin mold. Recently, however, solder heat resistance has been used for the purpose of improving productivity and reducing costs. Resin molding using a thermoplastic resin such as PPS or liquid crystal polymer having a certain property is performed. FIG. 13 is a cross-sectional view illustrating a piezoelectric oscillator in which an oscillation circuit is sealed with a thermoplastic resin using a conventional injection molding die, before bending a terminal.

In FIG. 13, reference numeral 4 denotes a quartz oscillator whose inside is omitted and the outer periphery of which is covered with a metal sealing tube; 4a, a lead terminal for extracting an electric signal; 4b, an end face of the head of the quartz oscillator 4; In addition, a concave portion in which a metal sealing tube portion is deformed by resin pressure during molding of a thermoplastic resin during resin molding is formed. 5a is a part of a lead frame, which is a metal lead terminal joined to the lead terminal 4a, 5b is an external terminal for electrically conducting with a circuit pattern (not shown),
5d is a through hole for integrating the resin and the lead frame 5 with the mold resin, 6 is an IC, 10 is a wire for electrically connecting the IC 6 deformed by the resin pressure to the circuit, and 8 is a resin, 2 shows a cross section of the heat-resistant resin cut in a plane substantially at the center.

[0008]

However, the technique disclosed in Japanese Patent Application Laid-Open No. 2-97109 has a structure in which the crystal resonator is fixed by protrusions formed in the upper and lower cavities. Not only is it difficult to adjust the mold for fixing the crystal unit, but it also requires a space for protrusions, which is particularly unsuitable for the structure of a molding mold that aims to reduce the thickness of a piezoelectric oscillator.

Also, as a measure against deformation or breakage of the metal sealing tube when the projection comes into contact with the crystal resonator, the contact is loosened so that the fixing is unstable and the crystal resonator moves during resin molding, There is also a problem that the thickness of the piezoelectric oscillator is limited depending on the height.

Next, when performing resin molding using a thermoplastic resin by the mold structure disclosed in Japanese Patent Application Laid-Open No. 1-262115, since the flow viscosity is higher than that of the conventional epoxy resin for sealing, the filling process is performed. As a result, there has been a problem that the slide component starts to move due to the resin pressure during the flow and the positioning of the insert component becomes unstable.

Also, the mold structure becomes complicated, the contour and step of the tip of the slide part remain on the upper surface of the molded product, and the appearance and the printing quality are deteriorated. The problem of having a protruding height and limiting the thickness of the molded product is the same as the technology disclosed in Japanese Patent Application Laid-Open No. 2-97109.

Further, as shown in FIG. 13, when an oscillation circuit is inserted into a conventional molding die and resin molding is performed using a PPS resin for sealing, the crystal vibration is lost due to the resin pressure during resin molding. The end face 4b of the metal-sealed tube head of the element 4 is recessed, the gap between the crystal inside the crystal unit 4 and the outer metal is narrowed, or the crystal comes into contact with the outer metal to cause an abnormal oscillation and stop the oscillation. Frequent rejects were an issue. In addition, there is a problem in that the wire 10 is deformed by the flow pressure at the time of resin molding, and there is a problem that the oscillation circuit is defective.

In the technique disclosed in Japanese Utility Model Registration No. 2543874, it is necessary to loosen the contact as a measure against deformation and breakage of the metal sealing tube when the mold surface is brought into contact with the quartz oscillator. Japanese Patent Laid-Open Publication No. Hei.
This is similar to the technology disclosed in Japanese Patent Application Laid-Open No. 97109 and Japanese Patent Application Laid-Open No. 1-262115, and the problem that the wire deforms during resin molding and comes into contact with other wires to cause a failure in the oscillation circuit is a problem shown in FIG. Same as the example.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and suppresses deformation and misalignment of parts by reducing the filling pressure on the parts while simplifying the mold structure. An object of the present invention is to achieve a thinner and smaller oscillator.

[0015]

The gist of the present invention to achieve the above object is to join a metal lead terminal of a lead frame on which an IC is mounted and a lead terminal of a crystal unit to form an integrated oscillator circuit. Insert the lead frame into the lead frame groove of the lower mold, position and insert the oscillation circuit including a part of the lead frame into the cavity formed by the upper mold and the lower mold, clamp the mold, and mold the piezoelectric with resin. In a mold for forming an oscillator, a gate for injecting a resin is provided on a side surface of a metal sealing tube of a quartz oscillator, and an overflow gate and the overflow gate are provided on at least one of a lead terminal side and a tip end side of the quartz oscillator. Are provided with dummy cavities outside.

Further, the mold is clamped in the vertical direction through a heat-resistant resin layer formed on the outer periphery of the quartz oscillator, and the overflow gate and the dummy cavity are extended from the quartz oscillator. The dummy cavity is formed in a part of the lead frame groove.

Further, in the resin mold of the piezoelectric oscillator using the molding die, a heat-resistant resin layer is formed on the outer periphery of the metal sealing tube of the quartz oscillator, and the heat-resistant resin layer is a coating film. Or a heat-resistant shrink tube made of silicone rubber, polyester elastomer, polyamide elastomer, or the like.

Further, the above-mentioned oscillation circuit is inserted between the upper cavity and the lower cavity of the molding die to perform mold clamping, and the quartz oscillator is inserted into the die through a heat-resistant resin layer on the outer periphery of the metal sealing tube. , And are securely held and resin-molded to manufacture a piezoelectric oscillator.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings. Embodiment 1 = Piezoelectric Oscillator FIG. 5 is a perspective view of a completed resin-molded piezoelectric oscillator, and FIG. 6 is a sectional view of a main part of the piezoelectric oscillator. In FIG. 5, reference numeral 4 denotes a crystal resonator exposed to the outside, and reference numeral 4a denotes a symbol indicating characteristics of the piezoelectric oscillator. Reference numeral 5b denotes an external terminal for electrically connecting to a pattern of a substrate (not shown), reference numeral 8 denotes a molded resin, and reference numeral 9 denotes a piezoelectric oscillator. Reference numeral 21 denotes a cut gate mark, 22 denotes a cut overflow gate mark, and 51 denotes an exposed cut surface of the lead frame.

In FIG. 6, 5 is a lead frame, 6 is an IC which is a component of the piezoelectric oscillator 9, and 7 is a heat-resistant resin layer for protecting the crystal unit 4. h is the height at which the crystal unit 4 protrudes from the upper surface of the resin-molded resin 8;
J indicates the resin injection direction. The other components are the same as those in FIG. 5, and the description is omitted using the same reference numerals and names.

The resin injection direction J is at the same plane position as the lead frame 5, and the injected resin flows along the side surface of the crystal unit 4. A lead frame 5 is disposed around the crystal unit 4, and the flow pressure of the resin is reduced by interference between the crystal unit 4 and the lead frame 5.

(Embodiment 2 = Mold Structure) FIG. 1 shows a lead frame to be inserted into a molding die according to Embodiment 1 of the present invention, on which an IC is mounted, and a cylindrical quartz oscillator is used as an oscillation circuit. FIG. 2 is a plan view showing a state where the lead frame is integrated, and FIG.
FIG. 2 is a plan view showing a state where the lead frame shown in FIG. 1 is inserted into the lower mold. FIG. 4 is a cross-sectional view illustrating the overall configuration of the clamped molding die.

In FIG. 1, reference numeral 4 denotes a crystal oscillator, and reference numeral 4a denotes a lead terminal for extracting an electric signal. 5 is a lead frame on which metal lead terminals and external terminals are formed, 5a
Is a metal lead terminal for electrical connection with the lead terminal 4a, 5b is an external terminal for electrical connection with a pattern of a substrate (not shown), 5c is a guide hole used for positioning in each processing, 5d is a through hole for coupling the lead frame 5 and the molding resin at the time of resin molding.

Reference numeral 6 denotes an IC for forming an oscillation circuit, reference numeral 10 denotes a wire for connecting the circuit forming portion of the lead frame to the IC 6, and reference numeral 11 denotes a range of a resin mold.
6 and a lead frame are joined by wires, and a lead terminal 4a of the crystal unit 4 is joined to a metal lead terminal 5a to form an oscillation circuit.

In FIG. 2, reference numeral 2 denotes a lower mold, 2a denotes a lower cavity filled with a thermoplastic resin, and 2d denotes a lower cavity 2.
a gate for injecting the resin into a, 2c is a resin pool for relaxing the flow pressure of the resin when passing through the gate 2d, and 2e is a resin pool for adjusting the flow pressure of the resin during the filling process of the thermoplastic resin. Overflow gate, 2b
Is a lead frame groove into which the lead frame 5 is inserted.

Reference numeral 2f denotes a dummy cavity functioning as an external resin reservoir. The volume of the dummy cavity 2f is determined so that the periphery of the oscillation circuit is completely sealed with resin while the dummy cavity 2f is filled with resin. ing.

In FIG. 3, the dummy cavity 2 f is disposed substantially at the center of the extension of the crystal unit 4 and below the lead frame 5. The other components are the same as those in FIGS. 1 and 2, and the description thereof will be omitted using the same reference numerals and names.

In FIG. 4, 1 is an upper mold, 1a is an upper cavity, 1b is a runner, 1c is a vertical runner which is a flow path of the resin from the runner 1b to the resin reservoir 2c. Reference numeral 3 denotes an upper plate on which a sprue is formed, and 3a denotes a sprue which is a starting point of a resin flow path. The resin injected from a nozzle of an injection molding machine (not shown) flows in the order of sprue 3a, runner 1b, and vertical runner 1c, and is injected from gate 2d to upper cavity 1a and lower cavity 2a via resin reservoir 2c.

Embodiment 3 = Method of Manufacturing Piezoelectric Oscillator
Hereinafter, a method of manufacturing a piezoelectric oscillator will be described with reference to FIGS. 1, 3, 5, and 7, 8, 9, 10, and 11 described above. FIG. 7 is a manufacturing process diagram of the piezoelectric oscillator in 11 steps from S1 to S11, FIG. 8 is a plan view of the lead frame 5, FIG.
FIG. 10 is a plan view of the frame 5 integrated with the IC 6, FIG. 10 is a perspective view of a lower mold having a concave portion for positioning the crystal unit 4, and FIG. 11 is a lead metal 5 having an oscillation circuit formed thereon. It is principal part sectional drawing explaining the state inserted in the type | mold and clamped.

In FIG. 7, S1 is a lead frame manufacturing process for processing the lead frame 5 into a strip material using a progressive feeding die. The configuration of the lead frame 5 will be described with reference to FIG.
8, reference numeral 5e denotes an IC arrangement space extended from the lead frame 5, W denotes a groove into which the quartz oscillator 4 is inserted, and 1 denotes a groove.
Reference numeral 1 denotes a resin mold area, and an oscillation circuit is formed by the lead frame, the quartz oscillator 4, the IC 6, and the wire 10 inside the resin mold.

In FIG. 7, step S2 is an IC bonding step of bonding the lead frame 5 and the IC 6. As shown in FIG. 9, after the IC 6 is die-bonded to the IC arrangement space 5e, each part of the lead frame 5 is And wire bonding.

In FIG. 7, in step S3, the quartz oscillator 4 is inserted into the groove W of the lead frame 5 to which the IC 6 is bonded and temporarily fixed.
This is a crystal resonator bonding step of bonding the lead terminal 4a and the metal lead terminal. The groove W has minute projections (not shown) that partially narrow the width, and has a structure that engages with the outer diameter of the sealing tube of the crystal unit 4. Quartz resonator 4 in groove W
Of the lead terminal 4a and the metal lead terminal 5
are joined by spot welding to form an oscillation circuit.

In FIG. 7, S4 is a lead frame insertion step of inserting the lead frame 5 having the oscillation circuit formed in the lower mold 2. In the lower cavity 2a of the lower mold 2 into which the lead frame 5 shown in FIG. 10 is inserted, there is formed a crystal oscillator positioning portion 2h whose cross section is an arc-shaped concave portion corresponding to the shape of the crystal oscillator 4. .

The crystal oscillator 4 of the oscillation circuit integrated with the lead frame 5 is inserted into the crystal oscillator positioning portion 2h, and the lead frame 5 is inserted into the lead frame groove 2b.
When the quartz oscillator 4 is positioned on the quartz oscillator positioning portion 2h, the entire lead frame 5 is provisionally positioned, and the insertion of the lead frame into the lower mold 2 is completed, as shown in FIG.

In FIG. 7, S5 is a mold clamping step,
When the upper die is aligned with the lower die in the above-described state, the pilot pin of the upper die (not shown) engages with the guide hole 5c of the lead frame 5, and then the pilot hole 2g of the lower die 2 and the pilot pin The leading end engages, and the lead frame 5 is completely immersed in the lead frame groove 2b of the lower mold 2, completing the mold clamping.

At this time, the quartz oscillator 4 is connected to the bottom surface of the upper cavity 1a and the quartz oscillator positioning portion 2h of the lower cavity 2a via the heat-resistant resin layer 7 (shown in FIG. 6) covering the outer periphery of the metal sealing tube. The contact is ensured and the holding is performed. FIG.
In the figure, reference numeral 2h denotes a quartz oscillator positioning portion, and the other portions are the same components as those in FIG. 4 described above, and the description is omitted using the same reference numerals and names.

In FIG. 7, S6 is a resin injection step. PPS resin for resin sealing (hereinafter referred to as resin) injected from a nozzle of an injection molding machine (not shown) flows in the order of sprue 3a, runner 1b, and vertical runner 1c shown in FIG. 11, and passes through resin reservoir 2c. The gate 2d is injected into the upper cavity 1a and the lower cavity 2a.

The resin injected into the outer peripheral side surface of the quartz oscillator 4 flows along the outer peripheral side surface, and furthermore, overflow gates provided in cavities on extension lines of the quartz oscillator 4 on the lead terminal side and the tip end side. 2e (shown in FIG. 10)
Reach

Further, by filling the resin reservoir 2c with the resin, the flow pressure of the resin passing through the gate 2d is reduced. Further, since the gate 2d is located at the same plane position as the lead frame 5, and the lead frame 5 is disposed around the quartz oscillator 4, the flow pressure of the resin is reduced by the interference between the quartz oscillator 4 and the lead frame 5. Is done.

In FIG. 7, S7 is an overflow step, in which the resin flows into the dummy cavity 2f through the overflow gate 2e. The resin pressure in the upper cavity 1a and the lower cavity 2a is equal to the overflow gate 2b.
Flows under a low pressure state limited by the flow resistance of the resin passing through the resin.

Until the dummy cavity 2f is filled with the resin, the resin flows and fills around the quartz resonator 4, the IC 6, and the wire 10 in the upper cavity 1a and the lower cavity 2a in a low pressure state and is extruded into the resin. The air and impurities in the cavity flow into the dummy cavity 2f from the overflow gate 2b.

In FIG. 7, S8 is a resin filling completion step. The dummy cavity 2f is filled with the resin, and the pressure of the flowing resin changes from a low flow pressure to a high filling pressure, and the resin filling into the upper cavity 1a and the lower cavity 2a is completed by the increase in the resin pressure.

At this time, resin is already filled in the periphery of the crystal unit 4, the joint between the lead terminal 4a and the metal lead terminal 5a, and the joint between the IC 6 and the lead frame 5 and the wire 10, and solidification has started. As a result, the high-flow resin is pushed into the unfilled portion only by the high resin pressure, so that the deformation of the insert part as described above does not occur.

In FIG. 7, S9 is a step of cutting the outer end of the terminal portion, in which the molded product is separated from the lead frame 5 by cutting the external terminal 5b and cutting the unnecessary lead frame 5 exposed on the outer periphery of the molded product. .

In FIG. 7, step S10 is a step of bending the terminal portion, in which the external terminal 5b projecting outward from the molded resin portion is processed so as to be surface mountable.

In FIG. 7, S11 is a printing process,
A symbol for discriminating the type and function is printed on the upper surface of the processed molded product, thereby completing the piezoelectric oscillator manufacturing process. FIG. 5 is a perspective view showing a completed state of the resin mold type piezoelectric oscillator. In the figure, 9 is a piezoelectric oscillator, 5b is an external terminal for surface mounting, 21 is a trace of a gate, 22 is a trace of an overflow gate, and 51 is a cut section of an exposed lead frame.

FIG. 12 is a sectional view showing a main part of an electronic device incorporating the piezoelectric oscillator 9 according to the present invention. By forming a concave portion 30a on the inner surface of the outer frame 30 of the device for the height h at which the crystal resonator 4 protrudes from the resin 8, the entire device can be made thinner. By adopting the above manufacturing process,
It is possible to provide a molding die for a resin-molded piezoelectric oscillator that is small, thin, and easy to mount, and a method for manufacturing the resin-molded piezoelectric oscillator.

In the above-described manufacturing process, a thermoplastic resin is used as a resin to be molded. However, a similar technique can be applied to a case where a conventional thermosetting resin is used. Further, by applying the above-described technology, it is possible to easily manufacture an extremely thin crystal resonator.

In the above description, the vibrator used for the piezoelectric oscillator is exclusively a quartz vibrator. Needless to say, the same effect can be obtained even if it is replaced with a vibrator.

[0050]

As described above in detail, in the method of manufacturing a resin-molded piezoelectric oscillator according to the present invention, the resin pressure does not increase during the process of filling the cavity because the mold structure is such that the resin flows under low pressure. Is filled with resin,
The defect caused by the conventional deformation was completely eliminated.

Further, the positioning of the inserted piezoelectric vibrator does not use a special member, and the piezoelectric vibrator is pressed against the inner surface of the cavity via the heat-resistant resin layer treated to the outer diameter of the piezoelectric vibrator, so that the piezoelectric vibrator can be reliably held. There was no trouble due to the movement of the piezoelectric vibrator during resin molding.

Further, by forming the semi-cylindrical projections over the entire longitudinal direction of the piezoelectric oscillator, a part of the outer diameter of the piezoelectric vibrator is exposed, and the device incorporating the piezoelectric oscillator can be made thinner.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a state in which an oscillation circuit inserted into an injection mold according to an embodiment of the present invention is integrated with a lead frame.

FIG. 2 is a perspective view of a lower mold and a lower cavity according to the embodiment of the present invention.

3 is a plan view illustrating a state in which the lead frame of FIG. 1 is inserted into a lower mold and a lower cavity of FIG. 2, which is an embodiment of the present invention.

FIG. 4 is a cross-sectional view illustrating a state in which a molding die according to an embodiment of the present invention is clamped.

FIG. 5 is a perspective view of a completed piezoelectric oscillator according to an embodiment of the present invention.

FIG. 6 is an enlarged cross-sectional view illustrating a main part of a piezoelectric oscillator according to an embodiment of the present invention.

FIG. 7 is a manufacturing process diagram of the piezoelectric oscillator according to the embodiment of the present invention.

FIG. 8 is a plan view of a lead frame pulled out by a progressive feeding type according to the embodiment of the present invention.

FIG. 9 is a plan view showing the lead frame in a state where the IC according to the embodiment of the present invention is die-bonded and then bonded to the lead frame by wire bonding.

FIG. 10 is a perspective view of the lower mold in which the concave portion for positioning the quartz oscillator is formed at the bottom of the cavity of the lower mold in the injection mold according to the embodiment of the present invention.

FIG. 11 is a cross-sectional view of a state in which a lead frame integrated with an oscillation circuit is inserted into a lower mold having a positioning concave portion according to the embodiment of the present invention and the mold is clamped.

FIG. 12 is a cross-sectional view of a main part in a state where the piezoelectric oscillator of the present invention is incorporated in a device.

FIG. 13 is a cross-sectional view of a piezoelectric oscillator in which an oscillation circuit is sealed with a thermoplastic resin using a conventional injection molding die before bending a terminal.

[Explanation of symbols]

 Reference Signs List 1 upper die 1a upper cavity 1b runner 1c vertical runner 2 lower die 2a lower cavity 2b lead frame groove 2c resin reservoir 2b gate 2e overflow gate 2f dummy cavity 3 upper plate 3a sprue 4 crystal oscillator 4a lead terminal 5 lead frame 5a Metal lead terminal 5b External terminal 6 IC 7 Heat resistant resin layer 8 Resin 9 Piezoelectric oscillator

Claims (6)

[Claims] A lead frame in which a metal lead terminal of a lead frame on which an IC is mounted and a lead terminal of a piezoelectric vibrator are joined and integrated as an oscillation circuit is inserted into a lower mold, and an upper mold and a lower mold are inserted. In a piezoelectric oscillator that positions and inserts the oscillation circuit including a part of the lead frame into a cavity formed by a mold and clamps and molds the resin, a gate for injecting a resin is provided on a side surface of a metal sealing tube of the piezoelectric vibrator. A piezoelectric oscillator, comprising: providing an overflow gate on at least one of a lead terminal side and a tip end side of the piezoelectric vibrator; and a dummy cavity outside the overflow gate, and performing resin molding. 2. A heat-resistant resin layer is provided on an outer periphery of the piezoelectric vibrator, and a vertical direction of the piezoelectric vibrator is brought into contact with a mold via the heat-resistant resin layer to perform resin molding. 3. The piezoelectric oscillator according to claim 1. 3. A lead frame in which a metal lead terminal of a lead frame on which an IC is mounted and a lead terminal of a piezoelectric vibrator are joined and integrated as an oscillation circuit is inserted into a lead frame groove of a lower mold, and In a molding die for a piezoelectric oscillator in which the oscillation circuit including a part of a lead frame is positioned and inserted into a cavity formed by a mold and a lower mold, and the mold is clamped and resin-molded, a gate for injecting a resin is provided with a gate of the piezoelectric vibrator. Along with providing on the side surface side of the metal sealing tube, providing an overflow gate on at least one of the lead terminal side and the tip end side of the piezoelectric vibrator and a dummy cavity outside the overflow gate, and performing resin molding. Mold for forming piezoelectric oscillators. 4. The method according to claim 1, wherein the overflow gate and the dummy cavity outside the overflow gate are formed in a part of the lead frame groove substantially at the center of a lead terminal side and a tip end side of the piezoelectric vibrator. The molding die for a piezoelectric oscillator according to claim 3. 5. A lead frame in which a metal lead terminal of a lead frame on which an IC is mounted and a lead terminal of a piezoelectric vibrator are joined and integrated as an oscillation circuit are inserted into a lead frame groove of a lower die, and an upper metal mold is formed. In a method of manufacturing a piezoelectric oscillator in which the oscillation circuit including a part of a lead frame is positioned and inserted into a cavity formed by a mold and a lower mold, the mold is clamped, and a resin is molded, a gate for injecting a resin is formed of a metal of a piezoelectric vibrator. It is provided on the side surface of the sealing tube, and an overflow gate is provided on at least one of the lead terminal side and the tip end side of the piezoelectric vibrator, and a dummy cavity is provided outside the overflow gate, and resin molding is performed. A method for manufacturing a piezoelectric oscillator. 6. A heat-resistant resin coating which is a heat-resistant resin coating or a heat-resistant elastic shrink tube made of silicone rubber, polyester elastomer, polyamide elastomer, or the like is provided on the outer periphery of the sealing tube of the piezoelectric vibrator. 6. The method for manufacturing a piezoelectric oscillator according to claim 5, wherein the vertical direction of the element is abutted to a mold via the heat-resistant resin layer to perform resin molding.