JPH11330859A - Piezoelectric oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact and thin piezoelectric oscillator for suppressing the increase of a temperature due to heat generated inside to stably supply high frequencies. SOLUTION: This piezoelectric oscillator 10 with an oscillator 50 in which a piezoelectric element 53 is housed in a case 51 is integrally formed with an IC chip 60 such as an IC for a PLL or the like from mold resin. The IC chip 60 is provided with a dummy electrode 62, and the dummy electrode 62 is connected through a wire bonding line 79 with an island 71. Also, a control electrode 63 of the IC chip 60 is connected with the island 71 in a grounded state so that oscillation frequencies can be controlled, so that the number of electrodes 63 to be connected with the island 71 can be increased the oscillation frequencies are increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric oscillator including a vibrator made of a piezoelectric element and a semiconductor integrated circuit device such as an IC or LSI connected to the vibrator.

[0002]

2. Description of the Related Art There are several types of piezoelectric oscillators in which a resonator and a semiconductor integrated circuit device are packaged. In the piezoelectric oscillator 10 shown in FIG. 27, a resonator 50 using a piezoelectric element such as a crystal resonator or a SAW resonator sealed in a substantially cylindrical case 51 and an IC chip 60 such as a CMOS type are arranged in parallel. It is arranged. Then, these are molded into a substantially rectangular shape by the molding resin 1 to form a piezoelectric oscillator molded into a plastic packaging type for surface mounting.

In this piezoelectric oscillator 10, an IC chip 60 is fixed to a plate-shaped island 71 of a lead frame 70 with a conductive adhesive or the like, and is disposed around the electrode 61 of the chip 60 and the island 71. The input / output leads 72 are connected by wire bonding wires 79. In addition, from the quartz oscillator or the SAW resonator housed in the case 51, the case 51
Two vibrator leads 52 extend to the outside of the lead frame.
3 is connected to a part of the electrode 61 of the IC chip 60. The vibrator 50, the IC chip 60, and the lead frame 70 having leads for various purposes are sealed by an epoxy-based resin molding material 1 by a transfer molding method or the like to form an integrated piezoelectric oscillator.

FIG. 28 shows a piezoelectric oscillator 20 in which an IC chip 60, a lead frame 70, and a vibrator 50 are stacked in this order, and are sealed in a substantially rectangular shape by the mold resin 1. Also in this piezoelectric oscillator 20, the IC chip 60 is fixed to the island 71 by a conductive adhesive or the like, and the electrode 61 and each lead of the chip 60 are connected to the wire bonding wire 79 similarly to the piezoelectric oscillator 10 described above.
Connected by The case 51 of the vibrator is arranged on the side of the island 71 opposite to the IC chip 60, and the vibrator leads 52 extending from the case 51 are connected to the IC chip 60 via connection leads 73. In the piezoelectric oscillator 20, since the vibrator 50, the IC chip 60, and the lead frame 70 are stacked and sealed with the epoxy resin molding material 1 by a transfer molding method or the like, the area required for mounting is as follows. It has the advantage of requiring less.

[0005] However, the diameter of the cylindrical case is as small as about 2 mm, and the thickness of the entire package is about 3.2 to 4.5 mm in consideration of the thickness of the lead frame and the IC chip. Therefore, the height of the package may be a problem when mounted on small and light electronic devices or OA devices such as FDDs, HDDs, home faxes, and portable telephones.

A structure in which an IC chip and a vibrator are arranged on opposite sides of an island is disclosed in Japanese Patent Application Laid-Open No. H5-2434.
No. 71 is also illustrated.

FIG. 29 shows a piezoelectric oscillator 3 in which an IC chip 60 and a crystal resonator or a SAW resonator 53 are housed and packaged in a ceramic package 31 instead of being integrated using a molding resin.
0 is shown. In this piezoelectric oscillator 30, an IC
The chip 60 is installed on the bottom surface 32 of the ceramic case 31 and is connected to a wiring (not shown) printed inside the ceramic case by a wire bonding wire 79.
The crystal resonator or the SAW resonator 53 is an IC chip 6
0 and are sealed by a metal or ceramic cover 39 in a state where they are stored.

[0008] These piezoelectric oscillators are used as clock sources for electronic devices such as computers, and the output frequency band is also 50 MHz in accordance with the speeding up of these electronic devices.
It is becoming as high as 125 MHz. In recent years, in addition to oscillators using quartz oscillators,
Further, a piezoelectric oscillator using a SAW resonator capable of stably oscillating a high frequency band has been realized, and it is required that these oscillators stably maintain a high output frequency of 100 MHz to 500 MHz.

As the oscillation frequency increases, the power consumption of a semiconductor integrated circuit device such as an IC used for a piezoelectric oscillator also increases. This is shown in FIG. For example, the current consumption of a piezoelectric oscillator at a power supply voltage of 5 V is:
About 38 mA at 80 MHz, about 45 mA at 100 MHz,
Approximately 55 mA at 125 MHz, 20 MHz to 30
The value is two to three times as large as about 10 mA to 17 mA at the time of frequency output of about MHz.

[0010]

As described above, the amount of heat generated by the IC increases due to the increase in the power consumption of the IC, so that the temperature of the entire piezoelectric oscillator increases. If the temperature inside the piezoelectric oscillator rises, the temperature at the junction of the IC rises, which may cause damage to each part of the IC, and may cause changes in the characteristics of the IC, thus deteriorating the reliability and quality of the IC. cause. In addition, if the temperature inside the piezoelectric oscillator rises and exceeds the operating temperature range of the crystal resonator or the SAW resonator, problems such as deterioration of accuracy of the oscillation frequency and occurrence of abnormal frequency fluctuation may occur. is there. Further, if the piezoelectric oscillator is continuously operated at a high temperature, long-term reliability is reduced due to aging.

On the other hand, electronic equipment on which a piezoelectric oscillator is mounted is becoming smaller and thinner, and the piezoelectric oscillator itself is also required to be smaller and thinner. For this reason, as the oscillation frequency increases, the amount of heat generated by the IC stored in the small and thin package increases more and more, and the temperature inside the package tends to be higher. Therefore, avoiding the above-described problem due to heat generation is urgently needed to provide a high quality piezoelectric oscillator with stable operation, and it is important to appropriately treat the heat generated in the package. Has become.

[0012]

SUMMARY OF THE INVENTION An object of the present invention is to provide a piezoelectric oscillator capable of supplying a high frequency stably and accurately. In particular, to provide a piezoelectric oscillator that can stably supply a high frequency by suppressing a temperature rise due to internally generated heat and that can be further reduced in size and thickness in response to electronic devices that are becoming faster and smaller. It is intended to be. It is another object of the present invention to provide a piezoelectric oscillator that can ensure long-term reliability by suppressing an increase in the internal temperature of the operating piezoelectric oscillator.

Therefore, according to the present invention, a heat radiation portion exposed outside the mold resin is provided on an island on which a semiconductor integrated circuit device generating a large amount of heat is installed, or on a case of a vibrator which is easily affected by a temperature rise. ing. That is, the piezoelectric oscillator according to the present invention includes a vibrator in which a piezoelectric element is sealed in a case, and a semiconductor integrated circuit device installed on an island of a lead frame. A piezoelectric oscillator in which the vibrator, the semiconductor integrated circuit device, and the lead frame are integrally molded by a mold resin, wherein the piezoelectric oscillator is connected by at least one part of a lead or the like constituting the lead frame; It is characterized by having a heat radiation portion exposed outside the mold resin.

These heat radiating portions can be constituted by connecting heat radiating leads extending outside the mold resin to the island or the case. A heat sink having at least a portion thereof exposed to the mold resin may be brought into contact with the island or the case. Further, at least a part of the island or the case may be exposed outside the mold resin. By laminating the island, the semiconductor integrated circuit device, and the vibrator in this order, a part of the island can be easily exposed from the mold resin, and the packaging can be reduced.

By providing these heat dissipating parts on the island, heat generated in the semiconductor integrated circuit device such as an IC chip can be dissipated directly to the outside of the mold resin, so that a high heat dissipating effect can be obtained. Therefore, heat generated in the semiconductor integrated circuit device can be dissipated without being confined in the piezoelectric oscillator. By suppressing the temperature rise in the piezoelectric oscillator, the thermal effect of the semiconductor integrated circuit device can be prevented. Can be reduced. Further, by providing a heat radiating portion to the case, heat transmitted from the semiconductor integrated circuit device can be radiated directly to the outside of the mold resin. Therefore, conduction of heat to the piezoelectric element inside the case can be prevented, and stable oscillation and long-term reliability can be secured. At the same time, the heat inside the piezoelectric oscillator can be released to the outside through the case, so that the temperature rise inside the piezoelectric oscillator can be suppressed,
The influence of heat in a semiconductor integrated circuit device or the like can also be suppressed.

In a piezoelectric oscillator in which a vibrator and a semiconductor integrated circuit device are integrated in parallel with a mold resin, the difference is used because the semiconductor integrated circuit device is thinner than the diameter (thickness) of the case of the vibrator. Thus, a heat sink can be provided. As a result, even in a small and thin piezoelectric oscillator, the effect of radiating heat from the outer surface of the molded package with the heat sink provided with the oscillator kept small can be enhanced.

Further, in order to suppress a rise in temperature of the vibrator, the vibrator connecting lead itself or a part thereof may be exposed outside the mold resin. If there is a concern about the influence of humidity outside the mold resin on the semiconductor integrated circuit device, place the conductive path of the vibrator lead or the lead frame connected to it near the surface inside the mold resin except for exposing the cut part. It is possible to enhance the heat radiation effect in a state where it is arranged so as not to be affected by the humidity.

In a piezoelectric oscillator in which the vibrator and the semiconductor integrated circuit device are housed in a ceramic package, an island pattern for installing the semiconductor integrated circuit device formed on the first layer in the package is formed. A high heat radiation effect can be obtained by extending a part of the package until it is exposed to the outside of the package.

The present invention will be described below in more detail with reference to the drawings, and other objects and effects of the present invention will be described in the following description and claims.

[0020]

(Embodiment 1) FIG. 1 shows a piezoelectric oscillator 10 according to Embodiment 1 of the present invention as viewed from the outside. FIG. 2 shows the internal arrangement of the piezoelectric oscillator 10 of the present example as viewed from above. The piezoelectric oscillator 10 of the present embodiment has a piezoelectric element in which a piezoelectric element 53 such as a quartz oscillator or a SAW resonator is sealed in a cylindrical case 51 and a CMOS type IC chip 60 arranged in parallel. It is an oscillator. These vibrators 50
The IC chip 60 is sealed in a substantially rectangular shape with the molding resin 1 by using a transfer molding method or the like, and the integrated piezoelectric oscillator 10 is formed. Further, a plurality of leads are exposed from the side surface 2 of the plastic package of the piezoelectric oscillator 10 formed by the molding resin 1.

In the molding resin, the IC chip 60 is provided with an island 71 formed in a flat plate shape of the lead frame 70.
Is fixed by a conductive adhesive or the like. Chip 6
Out of the plurality of electrodes 61 prepared for zero, the power supply and input / output electrodes are connected to the input / output leads 72 of the lead frame 70 by wire bonding wires 79. These leads 72 are provided on both sides 2 of the piezoelectric oscillator 10.
FIG. 2 shows a state in which the outer lead portion of the lead 72 extends from the side surface 2. FIG. 1 shows a so-called J-shaped bent outer lead portion of the lead 72.
This shows a state in which the lead has been obtained. These leads are
After being molded in the state of the frame, the tie bars connecting the leads are removed, and the lead is bent. J like this
The SOJ-shaped package type surface mount device provided with the lead has an advantage that the mounting area is small.

The vibrator 50 arranged substantially in parallel with the IC chip 60 inside the mold resin 1 has a substantially cylindrical case 51, and the piezoelectric element 53 is sealed inside the case 51. . The piezoelectric element 53 is an element using a piezoelectric body such as a quartz vibrating piece and a SAW resonance piece.
A specific frequency can be stably obtained in a frequency band reaching several tens MHz to 100 MHz, and further several hundred MHz. Two vibrator leads 52 connected to the internal piezoelectric element 53 extend from one end of the case 51, and each of the two leads leads to the gate G and the electrode G of the electrode 61 of the IC chip 60 via the connection lead 73 of the lead frame. It is connected to the drain D. The vibrator lead 52 is fixed to the connection lead 73 by a method such as resistance spot welding, soldering, or a conductive adhesive.

The piezoelectric oscillator 10 of the present embodiment further includes a heat radiation lead 11 formed continuously with the island 71 of the lead frame 70. This heat dissipation lead 1
Reference numeral 1 denotes a plate-shaped conductive member having substantially the same width as the island 71. The heat radiating lead 11 is formed integrally with the island 71, and is exposed to the outside from the side surface 2 of the package formed of the mold resin with almost the same width. The lead frame 70 is formed of a 42Alloy or Cu alloy-based highly conductive material of an Fe-Ni (Ni 42%) alloy, and the highly conductive material has a very high thermal conductivity. Therefore, the heat generated in the IC chip 60 is transmitted to the heat radiation lead 11 via the island 71 and is released to the outside of the piezoelectric oscillator 10. To further enhance the heat radiation effect from the heat radiation leads 11, for example, a heat radiation pattern may be printed on a substrate on which the piezoelectric oscillator 10 is mounted. Then, when the heat radiating lead 11 is brought into contact with the heat radiating pattern at the time of mounting, heat is conducted to the heat radiating pattern of the substrate through the heat radiating lead 11, so that the heat radiating effect can be further enhanced.

The lead 11 for heat radiation provided on the piezoelectric oscillator 10 of this embodiment so as to be connectable to the substrate is bent from the extended state shown in FIG. 2 to the J-shape shown in FIG. is there. It is desirable to provide a wide heat radiation lead 11 in order to enhance the heat radiation effect. However, if the heat radiation effect is wide, a crack or a crack may be generated in the mold resin due to a load at the time of bending. Therefore, in the piezoelectric oscillator 10 of the present embodiment, a plurality of holes 13 are formed along the edge of the mold resin 1 in a portion of the heat radiation lead 11 protruding outside the mold resin 1. Since the cross-sectional area of the heat-dissipating lead 11 in the portion formed by arranging these holes 13 is small, the load when bending into a J-shape can be small. Therefore, the mold resin 1
The heat radiation lead 11 can be processed without causing damage such as cracks and cracks to the lead. Further, since air circulates through these holes 13 provided in the heat radiation lead 11 bent in a J-shape, the heat radiation effect of the heat radiation lead 11 can be improved.

The heat radiating lead 11 is further provided with a slot 14 extending along the edge of the mold resin 1 in a portion to be accommodated in the mold resin 1. Heat dissipation lead 1
As described above, the mold resin 1 is formed to have a large width as described above, so that the mold resin 1 is divided into upper and lower portions by the heat radiating leads 11 so that peeling easily occurs. Therefore, in the piezoelectric oscillator 10 of the present embodiment, the holes 14 through which the molding resin flows into the heat radiation leads 11 are formed to prevent vertical separation. Particularly, in order to prevent peeling along the side surface 2 of the mold resin 1, the heat radiation lead 11 of this example is formed with a long hole 14 extending along the edge to enhance the integrity along the side surface 2. The peeling of the mold resin 1 is prevented. In this example,
By dividing the long hole 14 along the edge of the mold resin 1 into two, the cross-sectional area as the heat radiation lead 11 is also secured,
1, heat conduction is also performed well.

In the piezoelectric oscillator 10 of this embodiment, a heat radiation lead 12 is further attached to the case 51 of the vibrator 50.
One side is extended to the outside of the mold resin 1 and is exposed. The heat radiation lead 12 attached to the vibrator 50 is a heat radiation lead 11 connected to the island 71.
It is formed using a conductive plate material having substantially the same width as. Further, in order to prevent cracks, cracks, peeling, etc. from occurring in the mold resin 1, the heat radiating lead 12 is also provided with a plurality of holes 13 and a long hole 14 extending along the edge at the same position as the heat radiating lead. It is provided. The heat radiating lead 12 is disposed so as to be in contact with the periphery of the cylindrical case 51. In the piezoelectric oscillator 10 of the present embodiment, a good heat conductive adhesive containing a metal filler is included between the case 51 and the heat radiating lead 12. An agent or solder 15 is attached so that heat can be efficiently transmitted from the case 51 to the heat radiation leads 12.

When the heat radiating lead 12 is brought into contact with the case 51 or provided near the case 51, the heat of the case 51 or the vicinity of the case 51 can be efficiently radiated to the outside, so that the temperature rise of the case 51 can be suppressed. The case 51 is formed by the solder or the adhesive 15 as in this example.
When the heat radiation lead 12 is connected to the case 51, the case 51 and the heat radiation lead 12 come into contact with each other by a line or surface from a point. Therefore,
The heat that has reached the case 51 can be efficiently conducted to the heat radiating leads 12 and radiated. In order to further enhance the heat radiation efficiency of the heat radiation lead 12, a heat radiation pattern is provided on a mounting board, and the pattern and the heat radiation lead 12 are connected similarly to the heat radiation lead 11 connected to the island 71. it can. If the pattern is connected to the ground side, the case 51 is grounded via the heat radiation lead 12, and a shielding effect can be obtained. Furthermore, since the case 51 is fixed to the heat radiation lead 12 by solder or an adhesive 15, there is also an advantage that the position of the vibrator can be fixed with high precision when sealing with the molding resin by the transfer molding method.

In the piezoelectric oscillator 10 of this embodiment, one end 73a of the connection lead 73 to which the vibrator lead 52 is connected is extended so as to extend to the outside of the mold resin 1 and exposed in order to further obtain a heat radiation effect. . The ends 73a of the connection leads 73 are bent in a gull wing shape as shown in FIG. 1 so that the mounting leads 73 come into contact with the substrate to improve the heat radiation effect. The holes 13 and the elongated holes 14 may be provided as necessary in the same manner as the above-described heat radiation leads so that the molding resin is not damaged when the connection leads 73 are bent.

The vibrator lead 52 of the vibrator 50 is fixed to one end 73c of the connection lead 73 by welding or soldering. The connection leads 73 are also connected to connection electrodes of the IC chip 60 by wire bonding wires 79. Therefore, the IC is connected via the connection lead 73.
A path for conducting heat from the chip 60 to the vibrator 50 is formed.

Therefore, in the piezoelectric oscillator 10 of this embodiment, the side 73b of the connection lead 73 connected to the IC chip 60 is made thinner, and the connection lead 73
Reduces the amount of heat conducted through. Further, an end 73c of a connection lead connected to the transducer lead 52,
A heat dissipating end 73a extending to the outside of the mold resin 1 is provided between the end 73b connected to the C chip 60 and an IC 73
The heat transmitted from the chip 60 can be released. In addition, the width of the lead between the discharge end 73a and the end 73c connected to the vibrator lead is made relatively wide so that the heat applied to the vibrator 50 via the vibrator lead 52 can be easily released. I have. Furthermore, the distance between the end 73b connected to the IC chip 60 and the end 73a for heat dissipation is
The distance between the connected end 73c and the radiation end 73a is made longer so that the amount of heat conducted can be further reduced.

As described above, the piezoelectric oscillator 10 of the present embodiment has
A heat radiation lead 11 connected to the island 71 to which the C chip 60 is attached, and a heat radiation lead 12 connected to the case 51 of the vibrator 50 are provided.
A connection lead 73 connecting the chip 60 and the vibrator 50 is also provided with a heat radiating end 73a. Since the IC chip 60 and the vibrator 50 are arranged in parallel, the IC chip 6
0 is exposed to the side opposite to the vibrator 50, and the heat radiation lead 12 connected to the vibrator 50 is exposed to the side opposite to the IC chip 60, so that Thermal effects are minimized.
Therefore, heat generated in the IC chip 60 is transferred to the island 71.
The heat is efficiently radiated from the heat radiating lead 11 to the outside of the mold resin through the heat sink. Also, from the IC chip 60 to the vibrator 5
The heat transmitted to 0 is also radiated by the radiating leads 12 connected to the case 51. Further, connection leads 73
, The heat conducted to the vibrator 50 is also reduced.

As described above, the piezoelectric oscillator 10 of the present embodiment can efficiently radiate heat from the heat source,
The heat accumulated inside the package via 1 and the like is also released very efficiently. Therefore, the piezoelectric oscillator 10 of the present embodiment
By employing the above structure, the thermal resistance of the package can be significantly reduced. Thermal resistance is a measure of the heat generation or heat dissipation of a package.
Is determined by the following equation.

R = (T _j −T _a ) / P (1) Here, T _j is the temperature of the connection part (pn connection part) of the IC built in the piezoelectric oscillator. _Ta is the ambient temperature, and P is the power consumption.

The junction temperature T _j is a constant measured current I _M
Is proportional to the forward voltage V _MC when the current flows. Therefore, putting a piezoelectric oscillator 10 in a constant temperature bath at a temperature T _MC, by measuring the forward voltage V _MC at least two different points of the temperature T _MC, 3
To create a V _MC -T _MC diagram shown in. Next, electric power P is applied to the piezoelectric oscillator at the ambient temperature _Ta , and when the piezoelectric oscillator is thermally saturated, a constant value of the measurement current _IM is passed to immediately measure V _MC . Using this forward voltage V _MC , the junction temperature T _j is determined from the corresponding temperature from FIG. The details are based on MIL-STD-883C.

According to such a method, the oscillation frequency using the SAW resonator is 125 MHz and the maximum power consumption is about 0.
The thermal resistance of a 3 W oscillator was determined. This oscillator uses a Cu frame as a lead frame, and the volume of the plastic package is about 0.5 cc. In the above-described conventional piezoelectric oscillator having no heat radiation lead, the thermal resistance value R is about 145 ° C./W. On the other hand, in the piezoelectric oscillator having the heat radiation lead of the present example, the thermal resistance R decreases to about 100 ° C./W. Therefore, by adopting the structure of this example, about 70%
It can be seen that the thermal resistance of the package can be reduced. Simultaneously, simulations using heat conduction analysis software have been performed by the inventor of the present application, and the piezoelectric oscillator of this example has obtained a result in which the temperature near the built-in piezoelectric element is lower by about 5 ° C. than in the conventional case. Have been.

By reducing the thermal resistance of the piezoelectric oscillator, heat from a semiconductor integrated circuit device such as an IC chip mounted on the piezoelectric oscillator can be efficiently released. Therefore, the temperature rise in the piezoelectric oscillator is suppressed and the size is reduced.
A thinner piezoelectric oscillator can be realized. Further, in an oscillator in a high-frequency band, heat generation from the semiconductor integrated circuit device tends to increase, but since the temperature rise of the semiconductor integrated circuit device can be suppressed, damage and deterioration of the electrodes and the semiconductor integrated circuit device can be prevented, Further, the operation reliability of the semiconductor integrated circuit device can be secured. Further, since the thermal effect on the vibrator housed in the piezoelectric oscillator can be suppressed, abnormal frequency fluctuation of the vibrator can be prevented, and long-term reliability can be ensured.
As described above, since the above-described piezoelectric oscillator can ensure high reliability even when the thermal load of the IC chip increases, it is suitable as a high-frequency band piezoelectric oscillator using a SAW resonator and the like which has been recently developed. Things. In addition, a high-frequency piezoelectric oscillator with low thermal resistance and high reliability can be provided.

In the piezoelectric oscillator 10 of this embodiment, the heat of the IC chip 60 can be more efficiently released by using the wire bonding wire. The wire bonding wire connecting the electrode of the IC chip 60 and the lead is a conductor and has a very high thermal conductivity. Therefore, by connecting the electrode to the island 71 or the heat radiation lead 11, heat can be radiated from the surface of the IC chip 60 where the electrode 61 is provided. It is desirable to increase the number of wire bonding wires in order to promote heat radiation. Therefore,
In the piezoelectric oscillator 10 of this example, dummy electrodes 62 are provided on the IC chip 60, and these electrodes 62 and the islands 71 are connected by wire bonding wires 79 to promote heat radiation.

Further, in the piezoelectric oscillator 10 of this embodiment, the IC
The oscillation frequency of the chip 60 is controlled by connecting the control electrode 63 and the grounded island 71. In addition, the IC chip 60 is configured so that the number of electrodes 63 connected to the island 71 increases as the oscillation frequency increases, so that heat radiation in a high-frequency band where the amount of heat generation increases can be promoted. I having such a configuration
As the C chip 60, for example, the PLL I shown in FIG.
There is C.

The PLL IC 60 shown in FIG. 4 has three programmable dividers (PD) 81, 82 and 83.
Thus, a clock signal having a fixed frequency can be supplied. A signal from the oscillating unit 84 that supplies the reference clock signal connected to the vibrator 50 enters the first PD 81, and the signal divided by the PD 81 is input to the phase comparator 85. In the phase comparator 85, the first PD 8
1 is compared with a signal obtained by dividing the output of the voltage controlled oscillator (VCO) 87 by the second PD 82. The output of the phase comparator 85 has its high-frequency component cut by a low-pass filter 86 and is input to the VCO 87. The output of the VCO 87 is further divided by the third PD 83 and output from the IC 60 by the output unit 88. The reference clock signal supplied from the oscillating unit 84 is multiplied by such a circuit and output as a clock signal of a predetermined frequency. These three PDs 81, 82
And 83 are controlled by a decoder 89. The decoder 89 is provided with a PROM in which the division ratio of each PD is stored, and can output a clock signal of a desired frequency by three control terminals 63 of S0 to S2 whose states can be changed from the outside. .

FIG. 5 is a table showing the states of the control terminals S0 to S2 and the frequencies output from the PLL IC 60 based on the states. As can be seen from this figure, the control terminal S0
To S2 are all high level "1", that is, the control terminal S
The output frequency is set to be the lowest in a state where 0 to S2 are all open. On the other hand, the control terminal S
0 to S2 are all set to the low level "0", that is, the frequency is set to be the highest when the control terminals S0 to S2 are all grounded. Therefore, the PLL I
In C60, when operating at the highest frequency,
As shown in FIG. 2, all the control terminals 63 are connected to the island 71 by the wire bonding wires 79. Therefore, when the amount of heat generated by the PLL IC 60 in the high frequency band is increased, the IC chip 60 and the island 7
1 also increases the number of wire bonds 79 connecting
The heat radiation from the C chip 60 is promoted. The IC chip 60 may of course be a real-time clock IC having a real-time clock function for generating a clock signal for operation by the above-described PLL function and performing time measurement. Further, a semiconductor integrated circuit device having a frequency dividing function, such as a CMOS type oscillation circuit having no PLL circuit, may be used.

(Embodiment 2) FIG. 6 shows a state where a piezoelectric oscillator 10 according to Embodiment 2 of the present invention is viewed from the outside.
FIG. 7 shows an internal arrangement of the piezoelectric oscillator 10 of the present example as viewed from above. As can be seen from these figures, the piezoelectric oscillator 10 of the present example is an oscillator in which the vibrator 50 and the IC chip 60 are arranged in parallel and molded with a mold resin, as in the above-described embodiment. Are denoted by the same reference numerals and description thereof is omitted.

In the piezoelectric oscillator 10 of this embodiment, the exposed portions of the heat radiation leads 11 and 12 are extended without bending. The heat radiation leads 11 and 1
No. 2 can sufficiently obtain the heat radiation effect even in the extended state. Therefore, also in the piezoelectric oscillator 10 of the present embodiment, the effects of efficiently releasing the heat generated in the IC chip 60, suppressing the temperature rise in the mold resin, and reducing the temperature rise of the vibrator 50 can be obtained. .
Similarly to the above embodiment, a plurality of holes may be opened in the heat radiation leads 11 and 12 so that the heat radiation effect can be enhanced by circulation of air.

In the piezoelectric oscillator 10 of the present embodiment, the connection lead 73 connected to the vibrator lead 52 is connected to the cutting portion 73.
Except for g, it is not exposed outside the mold resin 1. Mounting environment of piezoelectric oscillator 10 and IC chip 60
Depending on the characteristics of the molding resin 1
If the IC chip 60 is exposed to the outside, the influence of humidity such as oscillation stop may appear on the IC chip 60. Therefore, in the piezoelectric oscillator 10 of the present embodiment, the connection lead 73 connected to the vibrator lead 52 is not exposed to the outside except for the cut portion 73g, so that the insulation between the gate G and the drain D is protected against changes in environmental humidity. Oscillating at a stable frequency. Instead of exposing the connection leads from the mold resin, a wide heat radiation area 73d is provided near the surface along the edge of the mold resin 1, and heat is radiated through the mold resin 1 which covers the heat radiation area thinly. The thickness of the package including the heat radiation region 73d can be smaller than the thickness of the package including the vibrator. The heat radiating region 73d has an end 73b connected to the IC chip 60 and an end 7b connected to the vibrator lead 52.
3c, the heat from the IC chip 60 is radiated in the heat radiation area 73d, and the influence on the vibrator 50 is reduced.

In order to minimize the influence of heat from the IC chip 60, a region 16 in which the lead 73 between the end 73b connected to the electrode of the IC chip 60 and the heat radiation region 73d is cut into a circle, A region 17 is provided. Since the cross-sectional area of the leads 73 is reduced in the regions 16 and 17 where these leads are cut, the amount of heat conducted is also reduced. Therefore, the influence of the heat generated by the IC chip 60 on the vibrator 50 can be further reduced.

(Embodiment 3) FIG. 8 shows a top view of the internal structure of a piezoelectric oscillator according to the present invention, and FIG. 9 shows its structure using a cross section. The piezoelectric oscillator 10 of the present embodiment also has a cylindrical case 51 similarly to the above embodiment.
This is a piezoelectric oscillator in which a vibrator 50 having the above structure and an IC chip 60 are arranged in parallel, and are sealed in a substantially rectangular shape by the mold resin 1. Note that the same reference numerals are given to portions common to the above-described embodiments, and description thereof will be omitted.

The IC chip 60 is mounted on one surface of the island 71 of the lead frame 70 of the piezoelectric oscillator of this example, that is, the upper surface 71a in FIG. 9 by a conductive adhesive or the like. Are connected to islands and other predetermined leads by wire bonding wires 79. In the lead frame of this example, the heat radiating plate 18 is further connected to the other surface of the island 71, that is, the surface 71b opposite to the surface 71a on which the IC chip 60 is mounted.

The heat radiating plate 18 is made of at least one member made of a material having good thermal conductivity such as a Cu alloy, and one end or the surface 18a is in contact with the surface 71b of the island. The other end or the surface 18 b is exposed from the mold resin 1. Heat sink 18
May be attached to the island 71 with solder or an adhesive having good thermal conductivity, but in this example, the surface 18a of the heat radiating plate that comes into contact with the island 71 is finished in substantially the same plane as the surface 71b of the island, and transfer-molded. At this time, good heat conduction is obtained by bringing the heat radiating plate 18 into close contact with the island 71. By attaching the heat radiating plate 18 to the island 71, a portion exposed from the island 71 to the outside of the mold resin 1 is formed, so that the heat generated in the IC chip 60 can be efficiently radiated similarly to the above embodiment. it can.

The vibrator 50 of this embodiment, which is arranged substantially in parallel with the IC chip 60, has a cylindrical case 51, in which a piezoelectric element 53 such as a rectangular AT crystal blank is housed. I have. Then, the piezoelectric oscillator 10 of the present embodiment
In this case, the heat radiating plate 18
A heat radiating plate 19 is attached so as to be substantially parallel to the above. The radiator plate 19 is made of one or more members formed of a material having good thermal conductivity like the radiator plate 18, and one surface 19 a of the radiator plate 19 is curved so as to be in close contact with the cylindrical case 51. Has become. Further, the other surface 19b is exposed to the outside from the mold resin 1. The heat radiating plate 19 forms a heat radiating portion exposed from the case 51 to the outside of the mold resin 1.
Therefore, the heat conducted to the case 51 is efficiently radiated to the outside via the radiator plate 19 as in the above-described embodiment, so that the heat effect on the piezoelectric element 53 sealed in the case can be suppressed.

In the piezoelectric oscillator 10 of the present embodiment, a heat sink 90 is further attached by utilizing a space above the IC chip 60. That is, at present, the thickness of the case 51 of the vibrator is almost 2 mm, no matter how small.
Degree is necessary. On the other hand, the thickness of the IC chip 60 is 1 mm or less, for example, about 0.4 mm. Therefore, a space filled with the mold resin 1 is formed above the IC chip 60 even when the IC chip 60 is mounted on the island 71. Therefore, in the piezoelectric oscillator 10 of the present embodiment, a heat sink 90 is attached to this space so that heat in the mold resin 1, particularly, heat conducted upward from the IC chip 60 can be released to the outside. FIG.
As can be seen, the heat sink 90 extends from the side surface 2 of the package formed by the mold resin 1 to the vicinity of the case 51 of the vibrator, so that heat can be radiated from the case 51 at the same time.

FIG. 10 shows the appearance of the piezoelectric oscillator 10 according to the present embodiment to which the heat sink 90 is attached. In this example, when performing transfer molding, molding is performed using a mold in which the space above the IC chip 60 is convex, and a concave portion 3 is formed on the outer surface of the piezoelectric oscillator 1 which is formed in a substantially rectangular shape by the molding resin 1. Form. Then, a heat sink 90 having a wide heat dissipation surface 91 made of metal such as aluminum is fixed to the recessed portion 3 with an adhesive having good heat conductivity. As described above, in the piezoelectric oscillator 10 of the present embodiment, the heat radiation effect is enhanced by mounting the heat sink 90 in the space above the IC chip, which is conventionally filled with the mold resin. Therefore, even if the heat sink 90 is attached, the size of the piezoelectric oscillator 1 does not increase, and a small, thin, and high heat radiation piezoelectric oscillator can be realized. Further, since the space conventionally filled with the mold resin can be reduced, a portion where heat is accumulated can be reduced.

FIG. 11 shows a state in which the piezoelectric oscillator of this embodiment is formed by using a transfer mold 100. The transfer mold comprises an upper mold 101 and a lower mold 102, each of which has recesses 103 and 104 for packaging the piezoelectric oscillator 10.
Is provided. Pins 105 and 106 for fixing the heat radiating plates 18 and 19 at predetermined positions are provided in the concave portion 104 of the lower mold 102. This pin 105
By providing the heat sink 106 and the heat sink 106, positioning of the heat sink can be easily performed, and troubles such as the heat sink moving or tilting due to the injection pressure of the resin at the time of molding can be prevented. In this embodiment, the heat sink needs to be fixed with a mold resin so that thermal contact with the island 71 or the case 51 can be ensured. desirable. In addition to the pins, it is of course possible to adopt a method such as making the transfer mold die uneven so that the position of the heat radiating plate can be accurately maintained.

The upper concave portion 103 of the mold 101 has a convex portion 10 for forming a concave portion 3 for installing a heat sink.
7 are provided. The lead frame 70 on which the vibrator 50 and the IC chip 60 are mounted and the heat radiating plates 18 and 19 are set in such a transfer mold 100, and resin molding is performed on the plastic package body by transfer molding except for the outside of the lead frame. . After molding, the tie bars and the like connecting the inner leads of the lead frame are cut and removed, and the outer lead portions protruding from the plastic package are bent. Further, by fixing the above-described heat sink 90 by bonding or the like, an oscillator having a SOJ package shape can be obtained.

The piezoelectric oscillator of this embodiment has a radiator plate 18 for mainly releasing heat generated from the IC chip 60 and a radiator plate 19 for mainly releasing heat transmitted from the vibrator case 51 to the vibrator.
Further, three means of a heat sink 90 for mainly releasing the heat accumulated in the mold resin package from the upper surface of the IC chip are provided so that the heat generated in the piezoelectric oscillator can be positively released. The piezoelectric oscillator of this example is provided with these heat sinks and heat sinks,
As described in detail in Example 1, the thermal resistance value is 50 to
It has been confirmed by experiments and the like that it can be reduced to about 70%. Therefore, the junction temperature of the IC chip is also lowered, and the reliability of the chip is very high. In addition, frequency fluctuation of the vibrator is suppressed, and long-term reliability is also ensured.

The heat radiated from the means such as the heat radiating plate or the heat sink can be freely adjusted by the size, material, etc., similarly to the heat radiated from the heat radiating lead of the above-described embodiment. Therefore, heat management of the IC chip, the vibrator, and the like can be individually and specifically performed. For this reason, it is possible to provide a piezoelectric oscillator designed based on optimal heat management in consideration of the amount of heat generated by each element or the influence of fluctuations in the external temperature. Of course, it is also possible to attach a heat sink instead of a heat sink, and vice versa. Also, the number of heat sinks is not limited to the number corresponding to each of the IC chip and the vibrator,
It is possible to provide a plurality of heat sinks for each element and adjust the amount of heat released depending on the location of the element. Further, a heat radiating plate common to the IC chip and the vibrator may be provided.

(Embodiment 4) FIG. 12 shows Embodiment 4 of the present invention.
13 is viewed from above, and FIG. 13 is viewed from the side.
The piezoelectric oscillator 20 of this example is a piezoelectric oscillator in which an IC chip 60, a lead frame 70, and a vibrator 50 are laminated in this order from below in FIG. Also in this piezoelectric oscillator 20, the IC chip 60 is fixed to the island 71 by a conductive adhesive or the like, and the electrode 61 of the chip 60 and each lead are connected by a wire bonding wire 79 in the same manner as the above-described piezoelectric oscillator 10. I have. Therefore, portions common to the above-described embodiments are denoted by the same reference numerals, and description thereof is omitted.

In the piezoelectric oscillator 20 of this embodiment, the case 51 of the vibrator is mounted on the surface 71b of the island 71 opposite to the surface 71a on which the IC chip 60 is mounted.
Then, two heat sinks 21a and 21b are connected to the suspension pin portions 74a and 74b of the lead frame connected to both sides of the island 71 on the surface 71a on which the IC chip is mounted. Therefore, the heat generated in the IC chip 60 through the island 71 is efficiently radiated, and
The temperature rise of the C chip 60 can be suppressed. Also, the vibrator 5
Since the amount of heat transmitted to the zero side is also reduced, the thermal effect of the vibrator 50 is also reduced.

The piezoelectric oscillator 20 according to the present embodiment includes an IC chip 60
And the vibrator 50 are stacked, so that the area required for mounting on a substrate can be reduced. However, since the entire oscillator becomes thick, a distance between the IC chip 60 and the vibrator 50 cannot be secured, and the vibrator is relatively easily affected by heat. Therefore, in the piezoelectric oscillator 20 of the present embodiment, as described above, the heat sinks 21a are attached to the suspension pin portions 74a and 74b.
And 21b, the heat from the IC chip 60 is actively released without increasing the thickness of the package,
The thermal effect on the vibrator 50 is suppressed.
Of course, the IC chip 60 and the vibrator 50 may be arranged in the reverse order as shown in FIG. However, if the heat radiating plate is exposed from the hanging pin portions 74a and 74b to the surface that comes into contact with the substrate as in this example, the heat radiating effect can be further enhanced by providing the substrate with a heat radiating pattern. Note that the number and position of the heat sinks are not limited to this example.

(Embodiment 5) FIG. 14 shows the internal arrangement of a piezoelectric oscillator 20 according to Embodiment 5 of the present invention as viewed from above, and FIG. 15 shows the arrangement as viewed from the side.
The piezoelectric oscillator 20 of the present embodiment is obtained by laminating a lead frame 70, an IC chip 60, and a vibrator 50 in this order, and sealing them with a mold resin. The vibrator 5
In the same manner as in the above embodiment, the same reference numerals are assigned to the same components as those of the above-described embodiment, and the description thereof is omitted.

The lead frame 70 of this embodiment is pressed so that the plate-like island 71 on which the IC chip 60 is mounted is displaced in the vertical direction in FIG. It is. The depressed amount h is set to be equal to or more than the thickness t of the IC chip 60. For example, when the thickness t of the IC chip 60 is 0.4 mm, the depressed amount h is set to about 0.5 mm. It is. When the dimensions are set in this manner, the cylindrical case 51 of the vibrator 50 is
Is disposed so as to be in contact with the suspension pin portion 74 of the IC chip 60.
A gap 22 of about 0.15 mm opens. This gap 2
By providing 2, the short circuit between the vibrator 50 and the IC chip 60 can be prevented. In addition, since the mold resin flows through the gap 22 at the time of filling, the filling property is improved.

In the piezoelectric oscillator 20 of this embodiment, several advantages can be obtained by stacking the lead frame 70, the IC chip 60 and the vibrator 50 in this order. First, the back surface 71 b of the island 71 of the lead frame 70 can be exposed outside the mold resin 1. The lead frame 70 is connected to the IC chip 60 and the vibrator 5
By disposing the IC chip 60 on the side opposite to the vibrator 50 instead of the IC chip 60, a part of the IC chip 60 can be exposed from the mold resin 1.

That is, on both sides of the lead frame 70, I
By disposing the IC chip 60 and the vibrator 50 on one side of the lead frame 70 instead of disposing the C chip 60 and the vibrator 50 respectively,
The other side can be taken out of the mold resin 1.
In this example, since the island 71 is depressed in the direction opposite to the direction in which the vibrator 50 and the IC chip 60 are arranged, the back surface 71b opposite to the surface 71a on which the IC chip is mounted is exposed. And the surface 71 of the island
Since the IC chip 60 is fixed to a by a conductive adhesive or the like, the heat generated in the IC chip 60 can be efficiently released by exposing the back surface 71b. Further, in the piezoelectric oscillator 20 of the present example, since the back surface 71b of the island is exposed on the side in contact with the substrate, the heat radiation effect can be enhanced by using the substrate, for example, by forming a pattern for heat radiation on the substrate. is there. As described above, the piezoelectric oscillator 20 of the present embodiment can realize a small-sized piezoelectric oscillator 20 having a high heat radiation effect and a small temperature rise.

Further, in the piezoelectric oscillator 20 of the present embodiment, the vibrator 50 is arranged in the space 23 on the surface 64 on which the electrode 61 is arranged on the surface of the IC chip 60. Therefore, the space 23 for wire-bonding the electrode and the lead can be used as a space for installing the vibrator 50,
The thickness of the entire piezoelectric oscillator can be reduced. The piezoelectric oscillator 20 of the type in which the IC chip 60 and the vibrator 50 are stacked requires a small mounting area, but requires a sufficient height on the substrate. On the other hand, in the piezoelectric oscillator 20 of the present embodiment,
Since the piezoelectric oscillator 20 can be made thin, the clearance on the substrate can be small, and the space required for mounting can be reduced. In particular, the vibrator 50 of this example includes a cylindrical case 51, and a case 51 is provided on the surface 64 of the IC chip 60.
The electrodes 61 are arranged along the longitudinal direction. Therefore,
It is possible to use a gap between the curved side surface of the case 51 and the surface of the IC chip as a wiring space between the electrode and the lead, and it is possible to wire the space from the case 51 in a loop shape with an appropriate interval. The interval is desirably, for example, about 0.2 mm or more.
It is possible to provide a compact piezoelectric oscillator that does not cause a short circuit.

Further, in the piezoelectric oscillator 20 of this embodiment,
The vibrator case 51 is connected to the suspension pin 74 of the lead frame.
Further, the lead frame 70 is provided on the back surface 71 of the island exposed outside the mold resin 1.
Supported from the outside. Therefore, the position of the vibrator 50 can be accurately determined during the transfer molding.

In the piezoelectric oscillator 20 of the present embodiment, since the vibrator and the IC chip are arranged on the same side of the lead frame, the manufacturing process is simplified, and the manufacturing with a high yield is possible. Further, the manufacturing cost can be reduced.

FIGS. 16 and 17 show an example of a transfer mold 100 used for manufacturing the piezoelectric oscillator 20 of this embodiment. This transfer mold 100 is similar to the mold described above in that the upper mold 1
01 and a lower mold 102, and concave portions 103 and 104 that determine the appearance of the piezoelectric oscillator 20 are formed in each of them. The case 51 of the vibrator has a lower mold 1 with its tip and the vibrator lead side supported by the suspension pin portions 74a and 74b of the lead frame.
Set to 02. Depressed part 1 of upper mold 101
03 is provided with pins 107 and 108 at locations that come into contact with the case 51. Therefore, when the upper mold 101 is set on the lower mold 102, the vibrator case 5
1 includes pins 107 and 108 and a hanging pin 7 from above and below.
4a and 74b. Further, the suspension pin portions 74a and 74b receive pressure from the island 71 in contact with the lower mold 102. For this reason, the case 51 of the vibrator is sandwiched between the upper and lower molds 101 and 102, and is fixed at a predetermined position of the mold 100. On the contrary, the back surface 71b of the island is pressed against the lower mold 102 by the upper mold 101 via the case 51 of the vibrator. Therefore, the back surface 71b of the island is in close contact with the surface of the mold 102, and the molding resin does not flow therebetween, so that the back surface 71 can be reliably exposed from the molding resin. Further, the mold 10
If a hole is provided in the second recess 104 so as to be covered by the back surface 71b of the island, the front surface of the mold 102 and the back surface 71b of the island are surely brought into contact by the action of the mold resin pressure. Therefore, it is possible to completely prevent the injected mold resin from reaching the back surface 71b of the island.

The tips of the pins 107 and 108 provided on the mold 101 can be formed in a curved shape in accordance with the surface of the cylindrical case 51, thereby further improving the positional accuracy in the horizontal direction. . As described above, in the transfer mold 100, the vibrator 50
Is determined very accurately. Therefore, the thickness of the mold resin that covers the vibrator 50 does not need to be set in consideration of the displacement of the case, and can be set to the minimum necessary thickness. In this example, for example, the minimum thickness above the case 51 can be set to about 0.15 mm in consideration of the filling property of the mold resin, and a very thin mold resin film is formed outside the case 51.

As described above, in the piezoelectric oscillator 20 of this embodiment, since the mold resin covering the vibrator case 51 is very thin, the overall height of the piezoelectric oscillator can be reduced to, for example, about 2.7 mm. Also, since it is only covered with a thin film-shaped mold resin, the heat radiation effect is also good.
The heat influence from the C chip is also reduced.

FIG. 18 shows the appearance of the piezoelectric oscillator 20 of this embodiment. In the upper surface 26 of the molded piezoelectric oscillator 20 of this example, a hole 24 and a recess 25 penetrating to the surface of the case 51 appear. These holes 24 and depressions 25 are traces of pins 107 and 108 formed in the mold. The diameter of the hole 24 is about 0.6 mm. The recess 25 is also used as a first pin mark indicating the position of the first pin of the piezoelectric oscillator 20. Piezoelectric oscillator 20 of this example
The tip 75 of the lead projecting from the side surface 2 is bent in a gull wing shape to form an SOP type 14-pin package.

FIG. 19 shows a state in which the vibrator lead 52 of the vibrator is connected to the connection lead 73 connected to the IC chip 60. Silver plating 27 is applied to a portion 73c of the connection lead 73 of the present example that is connected to the transducer lead 52, and the transducer lead 52 and the connection lead 73 are connected by resistance spot welding. In resistance spot welding, the connection end 73c of the connection lead and the vibrator lead 52 are sandwiched from above and below by a highly conductive electrode 28 such as chrome steel, and a large current is applied to weld the metal. The end 73c of the connection lead of this example is coated with silver plating 27 of about several μm on the surface, so that the current density at the welding interface is stable, and good welding without welding defects such as explosion can be performed. . This is particularly effective for welding different metals such as a Cu alloy lead frame forming the connection lead 73 and an iron alloy lead forming the vibrator lead 52. The silver plating on the connection leads 73 can be performed at the same time as the silver plating is performed on a portion (2nd bonding portion) of another lead frame where wire bonding is performed. That is, since the position where the wire bonding of the lead frame 70 is performed and the connection end 73c of the connection lead are on the same surface, silver plating can be performed in the same process. Accordingly, silver plating can be performed on the connection lead 73 without increasing the manufacturing cost or increasing the number of steps, and the reliability of the connection point between the vibrator and the lead can be increased. Thereby, a high quality piezoelectric oscillator can be provided.

FIG. 20 shows the configuration of the piezoelectric oscillator 20 of the present example in which the vibrator 50 is arranged on the side where the vibrator 50 is mounted on the substrate, as viewed from the side. In the piezoelectric oscillator 20, the bending direction of the outer lead 75 is set to the vibrator side opposite to the piezoelectric oscillator. Therefore, when the piezoelectric oscillator 20 is mounted, the back surface 71b of the island appears on the surface of the substrate, so that a high heat radiation effect can be obtained without flowing heat to the substrate.

FIGS. 21 and 22 show a QFP (Quad).
2 shows an example of a piezoelectric oscillator 20 of the present example having a flat package shape. By arranging the cylindrical case 51 along the diagonal line as in this example, the IC chip 60 and the vibrator 50 can be compactly combined to provide the miniaturized QFP-shaped piezoelectric oscillator 20. Also in the piezoelectric oscillator 20 of this example, the lead frame 70, the IC chip 60, and the vibrator 50 are stacked in this order, and the back surface of the island 71 is exposed. The piezoelectric oscillator 20 having a small thermal resistance value can be realized. Besides this,
QFJ (Quad Flat J-1 head Pack)
Ages) -shaped piezoelectric oscillator, SOJ (Small
Other shapes of packaged piezoelectric oscillators, such as Outline J-lead Packages), can be provided, and their height can be very thin, approximately 2.7 mm.

(Embodiment 6) FIGS. 23 and 24 show configurations of piezoelectric oscillators 10 and 20 according to Embodiment 6 of the present invention as viewed from the side. In the piezoelectric oscillator 10 shown in FIG. 23, an oscillator 50 and an IC chip 60 are arranged in parallel, and an outer lead 75 is bent into a J-shape.
This is a J-type piezoelectric oscillator. Further, the piezoelectric oscillator 20 shown in FIG.
And the vibrator 50 are laminated in this order, and the outer lead 75 is a SOP type piezoelectric oscillator bent into a gull wing shape. Since the main configurations of these oscillators 10 and 20 have already been described in detail in the above-described embodiment, common portions are denoted by the same reference numerals and description thereof will be omitted.

The piezoelectric oscillators 10 and 20 of this embodiment
In, the upper part of the case 51 of the cylindrical vibrator 50 is exposed from the mold resin 1. In the piezoelectric oscillator 10 of the present embodiment, the exposed portion 55 of the case is stopped within approximately one third of the circumferential cross section of the case, and the vibrator lead is exposed from the mold resin or the case 51 Troubles such as coming off of the mold resin are prevented beforehand. The case 51 of the present example is formed of a copper-nickel-zinc alloy, and has a structure shown in FIG.
In the OP type piezoelectric oscillator 10, the exposed surface 55 of the case is plated with nickel. By applying nickel plating to the exposed surface 55 of the case, it is possible to prevent solder from being erroneously attached. Therefore, even if the solder is melted and scattered in a reflow furnace or the like, it can be prevented from sticking to the surface 55 of the case. If the solder adheres in a reflow oven or the like and comes off after mounting, it may cause a short circuit and affect the reliability of the device. Can be prevented beforehand.

Further, fins 95 for heat radiation are attached to the exposed surface 55 of the vibrator shown in FIG. 24 using a conductive adhesive or the like. Therefore, the amount of heat transmitted to the case 51 can be efficiently released. In the piezoelectric oscillators 10 and 20 of these examples, a part of the case of the vibrator is exposed outside the mold resin. Therefore, not only the heat transmitted from the IC chip 60 to the case 51,
The heat accumulated in the mold resin can also be radiated through the case 51. Therefore, it is possible to suppress the thermal influence on the crystal unit and the SAW resonator provided inside the case 51.

(Embodiment 7) FIG. 25 shows Embodiment 7 of the present invention.
Is shown. The piezoelectric oscillator 30 according to the present embodiment includes a ceramic package 31 and an IC chip 6.
0 and a piezoelectric element 53 such as a quartz oscillator or a SAW resonator are housed therein and sealed with a metal or ceramic cover 39. FIG. 25A shows the package 31 with the cover 39 and the piezoelectric element 53 removed.
FIG. 25 shows a state in which the arrangement in FIG.
(B) and (c) show how the arrangement in the package 31 is viewed from the side. The inside of the package 31 of this example is divided into two layers, and the IC chip 60 is provided on a first layer corresponding to the bottom surface 32 of the package 31. Further, a step portion 33 is formed at a position higher than the IC chip 60 with the same ceramic or other insulating material as the package, and the upper surface 34 of the step portion 33 is formed with the second layer on which the piezoelectric element 53 is installed. Has become.

The bottom surface 32 corresponding to the first layer of the package 31
Is formed with an island pattern 76 metallized by printing.
An IC chip 60 is fixed thereon with a conductive adhesive or the like. This island pattern 76 is shown in FIG.
As shown in (c), the package 31 is exposed from the side surface 35 of the package 31 through the side walls 31a and 31c of the package 31. Further, the island pattern 76 is formed by a plurality of terminals 77 provided on the side surface 35 of the package. Connected with some. Therefore, the heat generated in the IC chip 60 is guided to the side surface 35 of the package by the island pattern 76 and is radiated. Further, since the island pattern 76 is connected to the terminal 77, the terminal 77 can be connected to a heat radiation pattern prepared on the substrate at the time of mounting. This allows
The heat generated in the IC chip 60 is transmitted to the terminal 77.
From the substrate to the substrate, and heat is efficiently dissipated. Since the island pattern 76 provided on the bottom surface 32 of the package can be formed by a printing method, a wide pattern can be easily obtained. Of course, the pattern may be formed using a metal foil, and the method of manufacturing the pattern is not limited to the above.

On the bottom surface 32, in addition to the island pattern 76, an input / output lead pattern 78 connected to the terminal 77 on the side surface is formed by printing or the like.
The electrodes 61 of the C chip and these patterns 78 are connected by wire bonding lines 79.

Further, the piezoelectric element 53 provided on the second layer
A connection lead pattern 38 for connecting the IC chip 60 to the IC chip 60 is formed from the bottom surface 32 to the second layer 34. In the piezoelectric oscillator 30 of this example, the piezoelectric element 53 and the IC
Two connection lead patterns 38 for connecting the chip 60
Are provided in the step 33 of the package. The connection lead pattern 38 includes a wide pattern 38 a formed on the first layer 32 for connection to the IC chip 60, and a wide pattern 38 formed on the second layer 34 for connection to the piezoelectric element 53. 38b, and these patterns 38a and 38b are connected by a thin conductive pattern 38c penetrating through the step 33. Therefore, the pattern 38a is transferred from the IC chip 60 through the wire bonding line 79.
When the heat is conducted to the second layer pattern 38b, the heat is not easily transmitted to the second layer pattern 38b by the thin conductive pattern 38c.

In the piezoelectric oscillator 30 in which the IC chip and the piezoelectric element are sealed in the ceramic package of the present embodiment, heat generated from the IC chip is efficiently released to the outside of the package via the island pattern 76, and Heat is hardly transmitted to 53 by the thin conductive path 38c. Therefore, even if the piezoelectric oscillator has a high oscillation frequency and generates a large amount of heat from the IC chip, the temperature rise of the IC chip can be suppressed low, and the effect of heat on the piezoelectric element can be prevented. As described above, the piezoelectric oscillator 30 of the present embodiment is a compact oscillator in which a semiconductor integrated circuit device such as an IC chip and a piezoelectric element such as a SAW resonator are sealed in a ceramic package, and a high-frequency-compatible semiconductor It can maintain high performance against heat generation of the integrated circuit device and maintain long-term reliability.

(Embodiment 8) FIG. 26 shows a piezoelectric oscillator 30 according to an embodiment of the present invention using a ceramic package different from the above embodiment. FIG. 26A shows the package 31 with the cover 39 and the piezoelectric element 53 removed.
FIG. 26 shows a state in which the inside is viewed from above.
(B) and (c) show how the arrangement in the package 31 is viewed from the side. The piezoelectric oscillator 30 of the present example has
First layer 32 on the bottom surface of the package where C chip 60 is installed
And a third layer in which lead patterns 78 and 38 are formed between the step portion 33 and the second layer on which the piezoelectric element 53 is provided.
Layer 36 is provided. That is, on the side wall of the ceramic package 31 of this example, a stepped portion 3 composed of two steps is provided.
3 is provided, and the surface of the intermediate stage is used as the third layer 36.

In the piezoelectric oscillator 30 of this embodiment, a third layer 36 different from the first layer 32 on which the IC chip 60 is provided is formed to form the input / output and connection lead patterns 78 and 38. Used. Therefore, there is no need to secure a space for the lead pattern in the first layer 32, so that the island pattern 76 can be formed in any shape. For example, it is possible to extend the island pattern 76 in any direction of the first layer, and to penetrate all of the side walls 31a to 31d to expose the side surfaces, thereby obtaining a large heat radiation effect. In this example, the island pattern 76 is not extended in the direction of the side wall 31d where the connection pattern 38 is formed so as to minimize the influence on the piezoelectric element 53 due to the heat indirectly conducted to the connection pattern 38. A high heat dissipation effect is obtained by penetrating the three walls.

Further, in the piezoelectric oscillator 30 of this embodiment, since the layers for the input / output pattern and the connection pattern are separately provided, it is easy to design these patterns.
A pattern matching the electrode arrangement of the IC chip can be created. Further, it is also possible to provide dummy electrodes 62 of the IC chip and connect them to the island pattern 76 with one or a plurality of bonding wires to suppress a rise in the temperature of the electrode side of the IC chip. The island pattern may be connected to the power supply side of the substrate instead of the dummy electrode, and further connected to the power supply electrode of the IC chip by a bonding wire. Since the island pattern 76 has a large area and can reduce the impedance of the power supply line, a margin can be provided on the power supply side. Of course, the island pattern 76 may be on the ground side, and may be connected to the control electrode of the IC chip 60 as described with reference to FIG.

[0083]

As explained based on the above embodiment,
The piezoelectric oscillator according to the present invention can efficiently release heat generated in a semiconductor integrated circuit device such as an IC chip to the outside of the piezoelectric oscillator. Further, the heat conducted to the vibrator and the piezoelectric element packaged in the same manner as the semiconductor integrated circuit device can be minimized, and furthermore, the heat can be radiated from the vibrator case to the outside of the piezoelectric oscillator. It has become. As described above, according to the present invention, it is possible to realize a piezoelectric oscillator which can be reduced in size and thickness, has a lower thermal resistance, and is less likely to be damaged by heat, and can be provided at a low cost. Further, since problems such as temperature rise and operational stability can be solved by the piezoelectric oscillator according to the present invention, the piezoelectric oscillator is configured using a piezoelectric element such as a SAW resonator that can obtain stable oscillation at a high frequency. Thus, it is possible to practically provide a small-sized piezoelectric oscillator that supplies a signal in a high-frequency band such as 100 to 500 MHz. Although the present invention has been described in detail using various embodiments, the present invention is not limited to the above embodiments, and the present invention can be variously modified based on the description in the claims. Further, the piezoelectric oscillator according to the present invention is not limited to the combinations described in the above embodiments, but can be realized in various combinations.

The piezoelectric oscillator of the present invention relates to a device for supplying a clock signal to an electronic device, and a surface mount device having a complex function such as a real-time clock module and a PLL module. It is suitable for electronic equipment.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an appearance of a piezoelectric oscillator according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an internal arrangement of the piezoelectric oscillator shown in FIG. 1 as viewed from above.

FIG. 3 is a graph for obtaining a thermal resistance value of the piezoelectric oscillator shown in FIG.

FIG. 4 shows a PLL I used in the piezoelectric oscillator shown in FIG.
It is a block diagram which shows the structure of C.

FIG. 5 is a table showing a method of selecting an oscillation frequency of the PLL IC shown in FIG. 4;

FIG. 6 is a perspective view illustrating an appearance of a piezoelectric oscillator according to a second embodiment of the present invention.

FIG. 7 is a top view of the internal arrangement of the piezoelectric oscillator shown in FIG. 6;

FIG. 8 is a top view of the internal arrangement of a piezoelectric oscillator according to a third embodiment of the present invention.

9 is a diagram showing a cross section of the piezoelectric oscillator shown in FIG.

FIG. 10 is a perspective view showing an appearance of the piezoelectric oscillator shown in FIG.

FIG. 11 is a view showing a state in which the piezoelectric oscillator shown in FIG. 8 is molded.

FIG. 12 is a diagram illustrating an internal arrangement of a piezoelectric oscillator according to a fourth embodiment of the present invention as viewed from above.

13 is a view of the inside of the piezoelectric oscillator shown in FIG. 12 from the side.

FIG. 14 is a diagram illustrating an internal arrangement of a piezoelectric oscillator according to a fifth embodiment of the present invention as viewed from above.

FIG. 15 is a view of the inside of the piezoelectric oscillator shown in FIG. 14 from the side.

FIG. 16 is a side view showing how the piezoelectric oscillator shown in FIG. 14 is molded.

FIG. 17 is a view showing a state in which the piezoelectric oscillator shown in FIG. 14 is molded, as viewed from a different side from FIG. 16;

18 is a perspective view showing an appearance of the piezoelectric oscillator shown in FIG.

19 is a diagram showing a state in which the lead of the vibrator and the connection lead are welded in the piezoelectric oscillator shown in FIG. 14;

FIG. 20 is a diagram of a different piezoelectric oscillator according to a fifth embodiment of the present invention when viewed from the side.

FIG. 21 is a top view of an internal arrangement of a different piezoelectric oscillator according to a fifth embodiment of the present invention.

FIG. 22 is a view of the inside of the piezoelectric oscillator shown in FIG. 21 from the side.

FIG. 23 is a side view of a piezoelectric oscillator according to a sixth embodiment of the present invention.

FIG. 24 is a side view of a piezoelectric oscillator of an example different from that of FIG. 23;

FIG. 25 is a diagram of a piezoelectric oscillator according to a seventh embodiment of the present invention;
(A) is a view of the inside arrangement viewed from above, and (b) and (c) are views of the inside viewed from the side.

FIG. 26 is a diagram of a piezoelectric oscillator according to an eighth embodiment of the present invention;
(A) is a view of the inside arrangement viewed from above, and (b) and (c) are views of the inside viewed from the side.

FIGS. 27A and 27B are diagrams showing an arrangement inside a conventional piezoelectric oscillator, wherein FIG. 27A is a diagram viewed from above and FIG. 27B is a diagram viewed from the side.

28A and 28B are diagrams showing an arrangement inside a conventional piezoelectric oscillator different from FIG. 27, wherein FIG. 28A is a diagram viewed from above, and FIG.
Is a view from the side.

FIG. 29 is a side view showing the internal arrangement of a conventional piezoelectric oscillator using a ceramic package.

FIG. 30 is a graph showing a relationship between an oscillation frequency and current consumption.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI H03H 9/02 H03H 9/02 KL // H01L 25/16 H01L 25/16 A

Claims (4)

[Claims] 1. A vibrator having a piezoelectric element sealed in a case and a semiconductor integrated circuit device provided on an island of a lead frame, wherein the semiconductor integrated circuit device is electrically connected to the vibrator. A piezoelectric oscillator in which the vibrator, the semiconductor integrated circuit device, and the lead frame are integrally molded with a mold resin, wherein the semiconductor integrated circuit device is connected to a part of the lead frame by wire bonding A piezoelectric oscillator comprising a dummy electrode. 2. The piezoelectric oscillator according to claim 1, wherein at least one of the island and the case includes a heat radiation portion exposed outside the mold resin. 3. A vibrator in which a piezoelectric element is sealed in a case, and a semiconductor integrated circuit device installed on an island of a lead frame, wherein the semiconductor integrated circuit device is electrically connected to the vibrator. A piezoelectric oscillator in which the vibrator, the semiconductor integrated circuit device, and the lead frame are integrally formed with a mold resin, wherein the semiconductor integrated circuit device includes a plurality of control devices for controlling an oscillation frequency. A piezoelectric oscillator comprising a pad, wherein when the number of the control pads connected to the lead frame is increased, the oscillation frequency is increased. 4. The piezoelectric oscillator according to claim 3, wherein at least one of the island and the case has a heat radiation portion exposed outside the mold resin.