JP6290066B2 - Temperature compensated piezoelectric oscillator - Google Patents

Description

  The present invention relates to a temperature-compensated crystal oscillator used for electronic equipment and the like.

  A temperature-compensated crystal oscillator generates a specific frequency using the piezoelectric effect of a crystal element. For example, a package having a substrate, a first frame provided on the upper surface of the substrate for providing the first recess, and a second frame provided on the lower surface of the substrate for providing the second recess. And a temperature-compensated crystal oscillator having a crystal element mounted on an electrode pad provided on the upper surface of the substrate and an integrated circuit element having a temperature sensor provided on the lower surface of the substrate (for example, , See Patent Document 1 below).

JP 2000-49560 A

  In the temperature compensated crystal oscillator described above, a crystal element is mounted in the first recess, and an integrated circuit element having a temperature sensor is mounted in the second recess. When such a temperature-compensated crystal oscillator is mounted on a mounting substrate such as an electronic device, the opening of the second recess is closed by the mounting substrate. In this state, when other electronic components mounted on the mounting board generate heat and the heat is transferred to the second recess through the mounting board, the air in the second recess is heated by the heat. Since the heated air stays in the second recess, the temperature around the integrated circuit element having the temperature sensor may increase. As a result, the ambient temperature of the crystal element differs from the ambient temperature of the integrated circuit element. When the temperature of the crystal element is corrected by the integrated circuit element, the oscillation frequency of the temperature compensated crystal oscillator varies. There was a risk of it.

  The present invention has been made in view of the above problems, and is a temperature compensation type capable of reducing the fluctuation of the oscillation frequency while suppressing the difference between the ambient temperature of the integrated circuit element and the ambient temperature of the crystal element. It is an object to provide a crystal oscillator.

  A temperature-compensated crystal oscillator according to an aspect of the present invention has a rectangular shape in plan view, a substrate provided with bonding terminals having predetermined thicknesses at the four corners of the lower surface, and a bonding member having predetermined thicknesses provided at the four corners of the upper surface. A mounting frame provided on the lower surface of the substrate by bonding the bonding pad and the bonding terminal, and a crystal element mounted on a pair of electrode pads provided on the upper surface of the substrate An integrated circuit element having temperature sensors mounted on a plurality of connection pads provided in a region surrounded by the mounting frame on the lower surface of the substrate, and a lid for hermetically sealing the crystal element And the substrate and the mounting frame body from the region surrounded by the mounting frame body on the lower surface of the substrate, passing between the bonding pads and the bonding terminals at two adjacent positions. Having a gap to the outer surface of And wherein the door.

  The temperature compensated crystal oscillator according to another aspect of the present invention is characterized in that the mounting frame is made of glass epoxy resin.

  Further, a temperature compensated crystal oscillator according to another aspect of the present invention is electrically connected to the electrode pad, and has a wiring pattern provided on the upper surface of the substrate, a measurement pad provided on the lower surface of the substrate, A via conductor that is electrically connected to the wiring pattern and the measurement pad and provided on the substrate, and the via conductor is provided at a position overlapping the mounting frame in plan view. Features.

  The temperature compensated crystal oscillator according to another aspect of the present invention is characterized in that an insulating resin is provided between the integrated circuit element and the lower surface of the substrate.

  The temperature compensated crystal oscillator according to another aspect of the present invention is characterized in that the insulating resin is provided so as to block a lower surface exposed portion of the via conductor on the lower surface of the substrate.

  A temperature-compensated crystal oscillator according to one aspect of the present invention includes a rectangular substrate, a frame provided on the upper surface of the substrate, and a bonding pad provided along the outer peripheral edge of the upper surface. The bonding terminals and bonding pads provided along the outer peripheral edge of the substrate are bonded to each other so that the mounting frame provided on the lower surface of the substrate and the region surrounded by the mounting frame are provided on the lower surface of the substrate. And an integrated circuit element having a temperature sensor mounted on the connection pad. In this way, a gap is provided between the lower surface of the substrate and the upper surface of the mounting frame. For example, the temperature compensated crystal oscillator of the present invention is mounted on a mounting substrate such as an electronic device. When mounted, even if other electronic components mounted on the mounting board generate heat and the heat is transferred to the second recess through the mounting board, the air heated by the heat Integrated with a temperature sensor mounted in the second recess, because the air heated through the gap is discharged outside without being trapped in the two recesses, and the outside air enters the second recess through the gap. The influence of heat on the circuit element can be reduced. Therefore, such a temperature-compensated crystal oscillator can reduce the difference between the ambient temperature of the integrated circuit element and the ambient temperature of the crystal element, so that the frequency temperature characteristics of the crystal element can be corrected reliably. As a result, fluctuations in the oscillation frequency can be reduced.

It is a disassembled perspective view which shows the temperature compensation type | mold crystal oscillator which concerns on this embodiment. (A) is AA sectional drawing of FIG. 1, (b) is BB sectional drawing of FIG. (A) is a perspective plan view seen from the upper surface of the package constituting the temperature compensated crystal oscillator according to the present embodiment, and (b) is a substrate of the package constituting the temperature compensated crystal oscillator according to the present embodiment. It is the see-through top view seen from the upper surface. (A) is the plane perspective view seen from the lower surface of the package which comprises the temperature compensation type | mold crystal oscillator which concerns on this embodiment, (b) is the plane perspective view which looked at the temperature compensation type crystal oscillator concerning this embodiment from the lower surface. FIG. (A) is a top view seen from the upper surface of the mounting frame which comprises the temperature compensation type | mold crystal oscillator which concerns on this embodiment, (b) is the mounting frame which comprises the temperature compensation type | mold crystal oscillator which concerns on this embodiment. It is the top view seen from the lower surface of the body. (A) is sectional drawing which shows the integrated circuit element vicinity of the temperature compensation type | mold crystal oscillator which concerns on the 1st modification of this embodiment, (b) is the temperature compensation type | mold which concerns on the 1st modification of this embodiment. It is sectional drawing which shows the mounting frame body vicinity of a crystal oscillator.

  As shown in FIGS. 1 and 2, the temperature-compensated crystal oscillator according to this embodiment includes a substrate 110, a crystal element 120 bonded to the upper surface of the substrate 110, and an integration bonded to the lower surface of the substrate 110. Circuit element 150. A mounting frame body 160 is provided on the lower surface of the substrate 110, and a second recess K <b> 2 surrounded by the lower surface of the substrate 110 and the inner surface of the mounting frame body 160 is formed. Such a temperature compensated crystal oscillator is used to output a reference signal used in an electronic device or the like.

  The substrate 110 has a rectangular shape in plan view, and functions as a mounting member for mounting the crystal element 120 mounted on the upper surface and the integrated circuit element 150 mounted on the lower surface. The substrate 110 is provided with an electrode pad 111 for mounting the crystal element 120 on the upper surface and a connection pad 115 for mounting the integrated circuit element 150 on the lower surface. A first electrode pad 111 a and a second electrode pad 111 b for bonding the crystal element 120 are provided along one side of the substrate 110. Bonding terminals 112 are provided at the four corners of the lower surface of the substrate 110. A pair of measurement pads 119 is provided at the center of the lower surface of the substrate 110, and six connection pads 115 for mounting the integrated circuit element 150 are provided so as to surround the pair of measurement pads 119. Further, the bonding terminals 112 are electrically connected to the four outside the connection pads 115.

  The substrate 110 is made of an insulating layer made of a ceramic material such as alumina ceramic or glass-ceramic. The substrate 110 may be one using an insulating layer or may be a laminate of a plurality of insulating layers. A wiring pattern 113 and a via conductor 114 for electrically connecting the electrode pad 111 provided on the upper surface and the measurement pad 119 provided on the lower surface of the substrate 110 are provided on and inside the substrate 110. Yes. Further, a connection pattern 116 for electrically connecting the connection pads 115 and the measurement pads 119 provided on the lower surface and the bonding terminals 112 provided on the lower surface of the substrate 110 is provided on the surface of the substrate 110. Yes.

  The electrode pad 111 is for mounting the crystal element 120. A pair of electrode pads 111 are provided on the upper surface of the substrate 110, and are provided adjacent to each other along one side of the substrate 110. The electrode pad 111 is electrically connected to the bonding terminal 112 provided on the lower surface of the substrate 110 through the wiring pattern 113 and the via conductor 114 provided on the upper surface of the substrate 110 as shown in FIGS. It is connected to the.

  As shown in FIG. 3, the electrode pad 111 is composed of a first electrode pad 111a and a second electrode pad 111b. The via conductor 114 includes a first via conductor 114a and a second via conductor 114b. The wiring pattern 113 is composed of a first wiring pattern 113a and a second wiring pattern 113b. The measurement pad 119 includes a first measurement pad 119a and a second measurement pad 119b. The first electrode pad 111 a is electrically connected to one end of the first wiring pattern 113 a provided on the substrate 110. The other end of the first wiring pattern 113a is electrically connected to the first measurement pad 119a through the first via conductor 114a. Therefore, the first electrode pad 111a is electrically connected to the first measurement pad 119a. The second electrode pad 111 b is electrically connected to one end of the second wiring pattern 113 b provided on the substrate 110. The other end of the second wiring pattern 113b is electrically connected to the second measurement pad 119b through the second via conductor 114b. Therefore, the second electrode pad 111b is electrically connected to the second measurement pad 119b.

  The joint terminal 112 is used for electrical joining with the joint pad 161 of the mounting frame 160. As shown in FIG. 4B, the junction terminals 112 are provided at the four corners of the lower surface of the substrate 110, and are constituted by a first junction terminal 112a, a second junction terminal 112b, a third junction terminal 112c, and a fourth junction terminal 112d. Has been. The junction terminals 112 are electrically connected to connection pads 115 provided on the lower surface of the substrate 110, respectively. The second joint terminal 112 b is electrically connected to the sealing conductor pattern 118 via the ground via conductor 117.

  The wiring pattern 113 is provided on the upper surface of the substrate 110 and is drawn from the electrode pad 111 toward the via conductor 114 of the nearby substrate 110. Moreover, the wiring pattern 113 is comprised by the 1st wiring pattern 113a and the 2nd wiring pattern 113b, as shown in FIG.

  The via conductor 114 is provided inside the substrate 110, and both ends thereof are electrically connected to the wiring pattern 113 and the measurement pad 119. The via conductor 114 is provided by filling a conductor in a through hole provided in the substrate 110. Further, the via conductor 114 is provided at a position overlapping the mounting frame 160 as shown in FIG. 4 in plan view. By doing so, the temperature compensated crystal oscillator according to the present embodiment reduces the stray capacitance generated between the mounting pattern on the mounting substrate of the electronic device or the like and the via conductor 114, thereby enabling the crystal element 120. Since no stray capacitance is added to the crystal element 120, fluctuations in the oscillation frequency of the crystal element 120 can be reduced.

  The connection pad 115 is used for mounting the integrated circuit element 150. Further, as shown in FIG. 4, the connection pad 115 includes a first connection pad 115a, a second connection pad 115b, a third connection pad 115c, a fourth connection pad 115d, a fifth connection pad 115e, and a sixth connection pad 115f. It is configured. The first connection pad 115a and the first bonding terminal 112a are connected by a first connection pattern 116a provided on the lower surface of the substrate 110, and the second connection pad 115b and the second measurement pad 119b are connected to the substrate 110. They are connected by a second connection pattern 116b provided on the lower surface. The third connection pad 115c and the fourth connection terminal 112d are connected by a third connection pattern 116c provided on the lower surface of the substrate 110, and the fourth connection pad 115d and the third connection terminal 112c are connected to the substrate 110. They are connected by a fourth connection pattern 116d provided on the lower surface. The fifth connection pad 115e and the first measurement pad 119a are connected by a fifth connection pattern 116e provided on the lower surface of the substrate 110, and the sixth connection pad 115f and the second bonding terminal 112b are connected to the substrate. They are connected by a sixth connection pattern 116 f provided on the lower surface of 110. The connection pattern 116 is provided on the lower surface of the substrate 110, and is drawn from the connection pad 115 toward the nearby bonding terminal 112 and the measurement pad 119.

  The sealing conductor pattern 118 plays a role of improving the wettability of the sealing member 131 when it is joined to the lid 130 via the sealing member 131. As shown in FIGS. 3 and 4, the sealing conductor pattern 118 is electrically connected to the second junction terminal 112 b through the ground via conductor 117. For the sealing conductor pattern 118, for example, nickel plating and gold plating are sequentially applied to the surface of a conductor pattern made of tungsten, molybdenum, or the like so as to surround the upper surface of the substrate 110 in an annular shape around the entire periphery of the upper surface of the substrate 110. For example, it is formed in the thickness of 10-25 micrometers.

  The measurement pad 119 is for measuring the characteristics of the crystal element 120 by bringing a contact pin or the like of the crystal element 120 into contact therewith. The measurement pad 119 includes a first measurement pad 119a and a second measurement pad 119b. The measurement pad 119 is electrically connected to the electrode pad 111 provided on the upper surface of the substrate 110 through the wiring pattern 113 and the via conductor 114 provided on the substrate 110. The first measurement pad 119a is electrically connected to the fifth connection pad 115e via the fifth connection pattern 116e. The second measurement pad 119b is electrically connected to the second connection pad 115b via the second connection pattern 116b. The measurement pad 119 is provided at a position overlapping the integrated circuit element 150 in plan view. By doing so, the stray capacitance generated between the mounting pattern on the mounting substrate of the electronic device or the like and the measurement pad 119 is reduced, so that no stray capacitance is added to the crystal element 120. Fluctuation of the oscillation frequency can be reduced.

  Here, the size of the measurement pad 119 will be described using an example in which the dimension of one side when the substrate 110 is viewed in plan is 1.0 to 2.0 mm. The long side length of the measurement pad is 0.5 to 0.8 mm, and the short side length is 0.45 to 0.75 mm. Further, since the crystal element 120 is measured before the mounting frame 160 is mounted, the area of the measurement pad 119 can be increased as compared with the conventional temperature compensated crystal oscillator. Since the area of the measurement pad 119 can be increased, contact failure between the contact pin and the measurement pad 119 can be reduced. Therefore, since remeasurement of the crystal element 120 caused by poor contact between the contact pin and the measurement pad 119 can be suppressed, the productivity of the temperature compensated crystal oscillator can be improved.

  Moreover, as an electrical property measuring instrument used when measuring the characteristics of the crystal element 120, a network analyzer that can measure equivalent parameters such as inductance and capacitance in addition to the resonance frequency and crystal impedance of the crystal element 120 or An impedance analyzer or the like is used. The contact pin is composed of a highly conductive pin in which the surface of an alloy such as copper or silver is gold-plated and a re-sectorable socket having a spring property that suppresses an impact at the time of contact. The measurement is performed by contacting with pressing.

  Here, a method for manufacturing the substrate 110 is described. When the substrate 110 is made of alumina ceramic, first, a plurality of ceramic green sheets obtained by adding and mixing an appropriate organic solvent or the like to a predetermined ceramic material powder is prepared. In addition, a predetermined conductor paste is applied to the surface of the ceramic green sheet or a through-hole previously punched by punching the ceramic green sheet by screen printing or the like. Further, these green sheets are laminated and press-molded and fired at a high temperature. Finally, a predetermined portion of the conductor pattern, specifically, the electrode pad 111, the bonding terminal 112, the wiring pattern 113, the via conductor 114, the connection pad 115, the connection pattern 116, the ground via conductor 117, and the sealing conductor pattern 118. Further, it is produced by applying nickel plating, gold plating, silver palladium, or the like to a portion to be the measurement pad 119. Moreover, the conductor paste is comprised from the sintered compact etc. of metal powders, such as tungsten, molybdenum, copper, silver, or silver palladium, for example.

  The mounting frame 160 is bonded to the lower surface of the substrate 110 and is used to form the second recess K2 on the lower surface of the substrate 110. The mounting frame 160 is made of an insulating substrate such as glass epoxy resin, and is bonded to the lower surface of the substrate 110 via a conductive bonding material 170. Inside the mounting frame 160, a conductor portion 163 for electrically connecting a bonding pad 161 provided on the upper surface and an external terminal 162 provided on the lower surface of the mounting frame 160 is provided. Bonding pads 161 are provided at the four corners of the upper surface of the mounting frame 160, and external terminals 162 are provided at the four corners of the lower surface. The external terminal 162 is electrically connected to the integrated circuit element 150.

  The bonding pad 161 is for electrically bonding to the bonding terminal 112 of the substrate 110 via the conductive bonding material 170. As shown in FIG. 5, the bonding pad 161 includes a first bonding pad 161a, a second bonding pad 161b, a third bonding pad 161c, and a fourth bonding pad 161d. As shown in FIG. 5, the external terminal 162 includes a first external terminal 162a, a second external terminal 162b, a third external terminal 162c, and a fourth external terminal 162d. The conductor part 163 includes a first conductor part 163a, a second conductor part 163b, a third conductor part 163c, and a fourth conductor part 163d. The first bonding pad 161a is electrically connected to the first external terminal 162a via the first conductor portion 163a, and the second bonding pad 161b is connected to the second external terminal 162b via the second conductor portion 163b. Electrically connected. The third bonding pad 161c is electrically connected to the third external terminal 162c via the third conductor portion 163c, and the fourth bonding pad 161d is connected to the fourth external terminal 162d via the fourth conductor portion 163d. Electrically connected.

  The external terminal 162 is for mounting the temperature-compensated crystal oscillator on a mounting board such as an electronic device. The external terminals 162 are provided at the four corners of the lower surface of the mounting frame 160. The external terminals 162 are electrically connected to four of the six connection pads 115 provided on the lower surface of the substrate 110. The second external terminal 162b is connected to a mounting pad connected to a ground potential that is a reference potential on a mounting board of an electronic device or the like. As a result, the lid 130 bonded to the sealing conductor pattern 118 is connected to the second external terminal 162b having the ground potential. Therefore, the shielding property in the 1st recessed part K1 by the cover body 130 improves. The first external terminal 162a is used as an output terminal, the third external terminal 162c is used as a functional terminal, and the fourth external terminal 162d is used as a power supply voltage terminal. The function terminal is used as a write / read terminal and a frequency control terminal. Here, the writing / reading terminal is a terminal for writing the temperature compensation control data into the storage element section or reading the temperature compensation control data written in the storage element section. The frequency control terminal is a terminal for correcting the temperature characteristic of the crystal element by changing the load capacitance of the variable capacitance diode of the oscillation circuit section when a voltage is applied.

  The conductor portion 163 is for electrically connecting the bonding pad 161 on the upper surface of the mounting frame 160 and the external terminal 162 on the lower surface. The conductor portion 163 is formed by providing through holes at the four corners of the mounting frame 160, forming a conductive member on the inner wall surface of the through hole, closing the upper surface with the bonding pad 161, and closing the lower surface with the external terminals 162. ing.

  The shape of the opening of the second recess K2 is a rectangular shape in plan view. Here, taking the case where the long side dimension when viewing the substrate 110 in plan view is 1.2 to 2.5 mm and the short side dimension is 1.0 to 2.0 mm, the second concave portion is taken as an example. The size of the opening of K2 will be described. The length of the long side of the second recess K2 is 0.8 to 1.5 mm, and the length of the short side is 0.5 to 1.2 mm.

  A method for bonding the mounting frame 160 to the substrate 110 will be described. First, the conductive bonding material 170 is applied onto the first bonding pad 161a, the second bonding pad 161b, the third bonding pad 161c, and the fourth bonding pad 161d by, for example, a dispenser and screen printing. The substrate 110 is transported so that the bonding terminals 112 of the substrate 110 are positioned on the conductive bonding material 170 and placed on the conductive bonding material 170. The conductive bonding material 170 is cured and contracted by being heated and cured. As a result, the bonding terminal 112 of the substrate 110 is bonded to the bonding pad 161. That is, the first bonding terminal 112a of the substrate 110 is bonded to the first bonding pad 161a, and the second bonding terminal 112b of the substrate 110 is bonded to the second bonding pad 161b. Further, the third bonding terminal 112c of the substrate 110 is bonded to the third bonding pad 161c, and the fourth bonding terminal 112d of the substrate 110 is bonded to the fourth bonding pad 161d.

Further, the bonding terminal 112 of the substrate 110 and the bonding pad 161 of the mounting frame body 160 are bonded through the conductive bonding material 170, so that the substrate 110 and the mounting frame body 160 are shown in FIG. A gap H corresponding to the sum of the thickness of the conductive bonding material 170, the thickness of the bonding terminal 112, and the thickness of the bonding pad 161 is provided. Thereby, for example, when the temperature-compensated crystal oscillator of this embodiment is mounted on a mounting board such as an electronic device, other electronic components such as power amplifiers mounted on the mounting board generate heat, Even if heat is transferred into the second recess K2 through the mounting substrate, the air heated by the heat does not stay in the second recess K2, and the air heated through the gap H is temperature compensated crystal oscillator. Since the outside air enters the second recess K2 through the gap H, the influence of heat on the integrated circuit element 150 having the temperature sensor in the second recess K2 can be reduced. . Therefore, the difference between the temperature around the integrated circuit element 150 and the temperature around the crystal element 120 can be reduced, and the oscillation frequency fluctuates by reliably correcting the frequency temperature characteristics of the crystal element 120. This can be reduced.

  Here, a method for manufacturing the mounting frame 160 will be described. When the mounting frame 160 is made of glass epoxy resin, it is manufactured by impregnating a base material made of glass fiber with an epoxy resin precursor and thermally curing the epoxy resin precursor at a predetermined temperature. In addition, a predetermined portion of the conductor pattern, specifically, the bonding pad 161 and the external terminal 162, for example, transfer a copper foil processed into a predetermined shape onto a resin sheet made of glass epoxy resin, and the copper foil is transferred. The formed resin sheets are laminated and bonded with an adhesive. The conductor portion 163 is formed by being deposited on the inner surface of the through hole formed in the resin sheet by printing or plating a conductor paste, or by filling the through hole. Such a conductor part 163 is formed by, for example, integrating a metal foil or a metal column by resin molding, or depositing it using a sputtering method, a vapor deposition method, or the like.

  As shown in FIGS. 1 and 2, the crystal element 120 is bonded onto the electrode pad 111 via a conductive adhesive 140. The crystal element 120 plays a role of oscillating a reference signal of an electronic device or the like by stable mechanical vibration and a piezoelectric effect.

  Further, as shown in FIGS. 1 and 2, the crystal element 120 has a structure in which an excitation electrode 122 and an extraction electrode 123 are attached to an upper surface and a lower surface of a crystal base plate 121, respectively. . The excitation electrode 122 is formed by depositing and forming a metal in a predetermined pattern on each of the upper surface and the lower surface of the quartz base plate 121. The excitation electrode 122 includes a first excitation electrode 122a on the upper surface and a second excitation electrode 122b on the lower surface. The extraction electrode 123 extends from the excitation electrode 122 toward one side of the crystal base plate 121. The extraction electrode 123 includes a first extraction electrode 123a on the upper surface and a second extraction electrode 123b on the lower surface. The first extraction electrode 123 a is extracted from the first excitation electrode 122 a and is provided so as to extend toward one side of the crystal base plate 121. The second extraction electrode 123 b is extracted from the second excitation electrode 122 b and is provided so as to extend toward one side of the crystal base plate 121. That is, the extraction electrode 123 is provided in a shape along the long side or the short side of the quartz base plate 121. In the present embodiment, one end of the crystal element 120 connected to the first electrode pad 111 a and the second electrode pad 111 b is a fixed end connected to the upper surface of the substrate 110, and the other end is between the upper surface of the substrate 110. The quartz crystal element 120 is fixed on the substrate 110 by a cantilevered support structure having a free end with a gap.

  Here, the operation of the crystal element 120 will be described. In the crystal element 120, when an alternating voltage from the outside is applied from the extraction electrode 123 to the crystal base plate 121 via the excitation electrode 122, the crystal base plate 121 is excited in a predetermined vibration mode and frequency. ing.

  Here, a manufacturing method of the crystal element 120 will be described. First, the crystal element 120 is cut from the artificial crystalline lens at a predetermined cut angle to reduce the thickness of the outer periphery of the crystal base plate 121, and the central portion of the crystal base plate 121 is thicker than the outer peripheral portion of the crystal base plate 121. The bevel processing provided is performed. The crystal element 120 is manufactured by forming the excitation electrode 122 and the extraction electrode 123 by depositing a metal film on both main surfaces of the crystal base plate 121 by a photolithography technique, a vapor deposition technique, or a sputtering technique. Is done.

  A method for bonding the crystal element 120 to the substrate 110 will be described. First, the conductive adhesive 140 is applied onto the first electrode pad 111a and the second electrode pad 111b by a dispenser, for example. The crystal element 120 is transported onto the conductive adhesive 140 and placed on the conductive adhesive 140. The conductive adhesive 140 is cured and contracted by being heated and cured. The crystal element 120 is bonded to the electrode pad 111. That is, the first extraction electrode 123a of the crystal element 120 is bonded to the second electrode pad 111b, and the second extraction electrode 123b is bonded to the first electrode pad 111a. As a result, the first joint terminal 112a and the third joint terminal 112c are electrically connected to the crystal element 120. The first bonding terminal 112a and the third bonding terminal 112c are bonded to the first bonding pad 161a and the third bonding pad 161c via the conductive bonding material 170, so that the first external terminal 162a and the third external terminal It is electrically connected to the terminal 162c. That is, the first external terminal 162a and the third external terminal 162c are electrically connected to the crystal element 120.

  The crystal element 120 is mounted such that the first wiring pattern 113a or the first via conductor 114a is disposed at a position facing the free end of the crystal element 120. By doing so, the free end of the crystal element 120 is not connected to the first wiring pattern 113a or the first via conductor even when the crystal element 120 is tilted about the location where the lead electrode 123 of the crystal element 120 and the electrode pad 111 are joined. Since it contacts 114a, it can suppress that the free end of the crystal element 120 contacts the upper surface of the board | substrate 110. FIG. If the drop test is performed with the free end of the crystal element 120 in contact with the substrate 110, the free end of the crystal element 120 may be lost. By doing in this way, it can reduce that the oscillation frequency of the crystal element 120 fluctuates, suppressing that the free end side of the crystal element 120 is missing.

  The conductive adhesive 140 contains conductive powder as a conductive filler in a binder such as silicone resin, and the conductive powder includes aluminum, molybdenum, tungsten, platinum, palladium, silver, titanium, One containing either nickel or nickel iron, or a combination thereof is used. Moreover, as a binder, a silicone resin, an epoxy resin, a polyimide resin, or a bismaleimide resin is used, for example.

  As the integrated circuit element 150, for example, a rectangular flip-chip type integrated circuit element having a plurality of connection pads is used, and a temperature sensor for detecting an ambient temperature state is provided on a circuit forming surface (upper surface), a crystal. Storage element unit for storing temperature compensation data for compensating temperature characteristic of element 120, temperature compensation circuit unit for correcting vibration characteristic of crystal element 120 according to temperature change based on temperature compensation data, and temperature compensation circuit unit thereof And an oscillation circuit unit that generates a predetermined oscillation output. The output signal generated by the oscillation circuit unit is output to the outside of the temperature compensated crystal oscillator via the first external terminal 162a of the mounting frame 160, and is used as a reference signal such as a clock signal, for example.

  The storage element unit is composed of PROM or EEPROM. Temperature compensation control data for the following three-dimensional function, which is a temperature compensation function, such as the third-order component adjustment value α, the first-order component adjustment value β, and the zero-order component adjustment value γ, are provided at the third external terminal. It is inputted from the writing / reading terminal 162c and stored. A register map is stored in the storage element section. The register map indicates what operation is performed when the control data is input to each address data and the control section reads the data and outputs a signal.

  The temperature compensation circuit unit includes a cubic function generating circuit, a quintic function generating circuit, and the like. For example, in the case of a cubic function generation circuit, the temperature compensation control data input to the storage element section is read, and a voltage derived from the temperature compensation control data with a cubic function is generated for each temperature. The external ambient temperature at this time is obtained from a temperature sensor in the integrated circuit element 150. The temperature compensation circuit unit is connected to the cathode of the variable capacitance diode, and a voltage is applied from the temperature compensation circuit unit. As described above, the frequency temperature characteristic is flattened by applying the voltage from the temperature compensation circuit unit to the variable capacitance diode and correcting the frequency temperature characteristic of the crystal element 120.

  As shown in FIG. 2, the integrated circuit element 150 is mounted on a connection pad 115 provided on the lower surface of the substrate 110 via a conductive bonding material 170 such as solder. Further, the connection terminal 151 of the integrated circuit element 150 is connected to the connection pad 115. The connection pad 115 is electrically connected to the bonding terminal 112 through the connection pattern 116. The bonding terminal 112 is electrically connected to the bonding pad 161 through the conductive bonding material 170. The bonding pad 161 is electrically connected to the external terminal 162 through the conductor portion 163. Therefore, the connection pad 115 is electrically connected to the external terminal 162 through the bonding terminal 112. The second external terminal 162b serves as a ground terminal by being connected to a mounting pad that is connected to a ground that is a reference potential on a mounting board of an electronic device or the like. Therefore, one of the connection terminals 151 of the integrated circuit element 150 is connected to the ground that is the reference potential.

  The temperature sensor provided in the integrated circuit element 150 is provided so as to be positioned in the measurement pad 119 in plan view. By doing so, heat transferred from the crystal element 120 to the measurement pad 119 from the electrode pad 111 via the wiring pattern 113 and the via conductor 114 is dissipated from the measurement pad 119, and the integrated circuit element 150. It is transmitted to the temperature sensor provided inside. Therefore, since the temperature compensation type crystal oscillator can shorten the heat conduction path, the temperature of the crystal element 120 and the temperature of the integrated circuit element 150 are approximated, and the temperature sensor of the integrated circuit element 150 is obtained. The difference between the temperature and the actual temperature around the quartz crystal element 120 can be further reduced.

  A method for bonding the integrated circuit element 150 to the substrate 110 will be described. First, the conductive bonding material 170 is applied to the connection pad 115 by a dispenser, for example. The integrated circuit element 150 is placed on the conductive bonding material 170. The conductive bonding material 170 is melt bonded by heating. Therefore, the integrated circuit element 150 is bonded to the connection pad 115.

  Further, the integrated circuit element 150 has a rectangular shape in plan view as shown in FIGS. 1 and 2, and six connection terminals 151 are provided on the lower surface thereof. Three connection terminals 151 are provided along one side, and three connection terminals 151 are provided along one side facing the one side. The long side length of the integrated circuit element 150 is 0.5 to 1.2 mm, and the short side length is 0.3 to 1.0 mm. The length of the integrated circuit element 150 in the thickness direction is 0.1 to 0.3 mm.

  The conductive bonding material 170 is made of, for example, silver paste or lead-free solder. The conductive bonding material contains an added solvent for adjusting the viscosity to be easily applied. The component ratio of the lead-free solder is 95 to 97.5% for tin, 2 to 4% for silver, and 0.5 to 1.0% for copper.

The lid 130 is made of an alloy containing at least one of iron, nickel, and cobalt, for example. The outer shape of the lid 130 is a shape in which the box-shaped member having the first recess K1 is turned upside down, and the contact portion with the sealing conductor pattern 118 formed on the substrate 110 is an L-shaped flange. Yes. The lid 130 has a flange portion in contact with a band-shaped region of the sealing conductor pattern 118 formed on the inner periphery of the substrate 110, and the crystal element 120 is accommodated in the first recess K1. Placed on top. Such a lid 130 is for hermetically sealing the first recess K1 in a vacuum state or the first recess K1 filled with nitrogen gas or the like. Specifically, the lid 130 is placed on the upper surface of the substrate 110 in a predetermined atmosphere, and the sealing conductor pattern 118 of the substrate 110 and the sealing member 131 provided on the flange portion of the lid 130 are welded. As described above, the seam welding is performed by applying a predetermined current to join the substrate 110. The lid 130 is electrically connected to the second bonding terminal 112 b on the lower surface of the substrate 110 via the sealing conductor pattern 118 and the ground via conductor 117. The second bonding terminal 112b is electrically connected to the second bonding pad 161b through the conductive bonding material 170 . The second bonding pad 161b is electrically connected to the second external terminal 162b through the second conductor portion 163b. Therefore, the lid body 130 is electrically connected to the second external terminal 162b of the mounting frame body 160.

  The sealing member 131 is provided at the flange portion of the lid 130 facing the sealing conductor pattern 118 provided on the upper surface of the substrate 110. The sealing member 131 is provided by, for example, silver solder or gold tin. In the case of silver wax, the thickness is 10 to 20 μm. For example, the component ratio is 72 to 85% for silver and 15 to 28% for copper. In the case of gold tin, the thickness is 10 to 40 μm. For example, the component ratio is 78 to 82% for gold and 18 to 22% for tin.

  The temperature-compensated crystal oscillator in the embodiment of the present invention includes a substrate 110 having a rectangular shape in plan view, and a bonding pad 161 provided along the outer peripheral edge of the upper surface, and is provided along the outer peripheral edge of the lower surface of the substrate 110. A bonding frame body 160 provided on the lower surface of the substrate 110 is provided by bonding the bonding terminals 112 and the bonding pads 161. By doing so, the gap H is provided between the lower surface of the substrate 110 and the upper surface of the mounting frame 160. For example, the temperature compensated crystal oscillator of the present invention is an electronic device or the like. When mounted on the mounting board, other electronic components mounted on the mounting board generate heat, and even if the heat is transferred into the second recess K2 through the mounting board, it is heated by the heat. Since the heated air does not stay in the second recess K2 and the heated air is discharged to the outside through the gap H and the outside air enters the second recess K2 through the gap H, the inside of the second recess K2 The influence of the heat on the integrated circuit element 150 having the temperature sensor mounted on can be reduced. Therefore, such a temperature-compensated crystal oscillator can reduce the difference between the temperature measured by the temperature sensor and the temperature around the actual crystal element 120, so that the frequency temperature characteristics of the crystal element 120 can be ensured. By correcting to, fluctuations in the oscillation frequency can be reduced.

  In the temperature compensated crystal oscillator according to the embodiment of the present invention, the via conductor 114 is provided at a position overlapping the mounting frame 160 in plan view. By doing so, the stray capacitance generated between the mounting pattern on the mounting substrate of the electronic device or the like and the via conductor 114 is reduced, so that the stray capacitance is not added to the crystal element 120. It is possible to reduce the fluctuation of the oscillation frequency. In the temperature compensated crystal oscillator according to the embodiment of the present invention, the measurement pad 119 is provided at a position overlapping the integrated circuit element 150 in plan view. By doing so, the stray capacitance generated between the mounting pattern on the mounting substrate of the electronic device or the like and the measurement pad 119 is reduced, so that no stray capacitance is added to the crystal element 120. Fluctuation of the oscillation frequency can be further reduced.

(First modification)
Hereinafter, the temperature compensated crystal oscillator according to the first modification of the present embodiment will be described. Of the temperature-compensated crystal oscillator in the first modification of the present embodiment, the same parts as those of the above-described temperature-compensated crystal oscillator are denoted by the same reference numerals and description thereof is omitted as appropriate. As shown in FIG. 6, the temperature-compensated crystal oscillator according to the first modification of the present embodiment has four gap portions H provided between the lower surface of the substrate 110 and the upper surface of the mounting frame 160. Among them, the present embodiment is different from the present embodiment in that two gap portions H where the exposed portion of the via conductor 114 is exposed and an insulating resin 180 is provided between the integrated circuit element 150 and the lower surface of the substrate 110.

  As shown in FIG. 6A, the insulating resin 180 is provided between the surface of the integrated circuit element 150 where the connection terminal 151 is provided and the lower surface of the substrate 110. By doing so, the insulating resin 180 can increase the adhesive strength between the integrated circuit element 150 and the lower surface of the substrate 110. Further, even if a foreign substance such as solder enters the second recess K2 when the temperature-compensated crystal oscillator is mounted on a mounting pad of a mounting board of an electronic device or the like, the insulating resin 180 Since foreign matter is prevented from adhering between the connection terminals 151 of the integrated circuit element 150, a short circuit between the connection terminals 151 of the integrated circuit element 150 can be reduced. The insulating resin 180 is made of an epoxy resin or a resin material such as a composite resin mainly composed of an epoxy resin.

  Further, the insulating resin 180 may be provided so as to cover the measurement pad 119. By doing so, it is possible to suppress foreign matter from adhering to the measurement pad 119, and thus it is possible to suppress the additional resistance of the foreign matter from being applied to the crystal element 120. Therefore, fluctuations in the oscillation frequency of the crystal element 120 can be reduced.

  As shown in FIG. 6B, the insulating resin 180 is a via conductor 114 in the four gaps H provided between the lower surface of the substrate 110 and the upper surface of the mounting frame 160. It may be provided up to the two gaps H where the lower surface exposed portion is located. By doing so, the insulating resin 180 can improve the bonding strength between the lower surface of the substrate 110 and the upper surface of the mounting frame 160. Further, the insulating resin 180 blocks the exposed portion of the lower surface of the via conductor 114 on the lower surface of the substrate 110, and the outer peripheral edge of the lower surface of the via conductor 114 is fixed to the substrate 110 with the insulating resin 180. By doing so, even if the substrate 110 is warped, the via conductor 114 is fixed by the insulating resin 180, so that the via conductor is formed from the interface between the outer peripheral edge of the via conductor 114 and the substrate 110. It can reduce that 114 peels. Further, by reducing the peeling of the via conductor 114 from the interface between the outer peripheral edge of the via conductor 114 and the substrate 110, there is no gap at the interface between the via conductor 114 and the substrate 110, and the airtightness of the substrate 110 is reduced. Can be improved. Even if the two gaps H where the lower surface exposed portion of the via conductor 114 is blocked by the insulating resin 180, the four gaps H provided between the upper surface and the mounting frame 160 are included. Since there are two remaining gaps H, it is possible to achieve the effects of the present invention.

  A method for forming the insulating resin 180 will be described. The tip of the resin dispenser filled with the insulating resin is inserted into the gap of the second recess K2, and the insulating resin 180 is injected. Next, the injected insulating resin 180 is heated and cured. Therefore, the insulating resin 180 includes two gap portions H that are exposed between the lower surface of the via conductor 114 and the gap portion H provided between the lower surface of the substrate 110 and the upper surface of the mounting frame 160, and Provided between the integrated circuit element 150 and the lower surface of the substrate 110.

  In addition, it is not limited to this embodiment, A various change, improvement, etc. are possible in the range which does not deviate from the summary of this invention. In the above embodiment, the case where an AT crystal element is used as the crystal element has been described. However, a tuning fork-type bent crystal having a base and two flat plate-shaped vibrating arms extending in the same direction from the side surface of the base. An element may be used.

  A bevel processing method for the crystal element 120 will be described. A polishing material provided with media and abrasive grains having a predetermined particle size and a quartz base plate 121 having a predetermined size are prepared. The abrasive prepared in the cylindrical body and the quartz base plate 121 are placed, and the open end of the cylindrical body is closed with a cover. The quartz base plate 121 that rotates the cylindrical body containing the abrasive and the quartz base plate 121 with the central axis of the cylindrical body as the rotation axis is polished with the abrasive and beveled.

  Moreover, although the case where the conductor part 163 was provided in the board | substrate was demonstrated in the said embodiment, you may provide in the inside of the notch provided in the corner | angular part of the mounting frame 160. FIG. At this time, the conductive portion is provided so as to print the conductor paste in the cut.

DESCRIPTION OF SYMBOLS 110 ... Board | substrate 111 ... Electrode pad 112 ... Joint terminal 113 ... Wiring pattern 114 ... Via conductor 115 ... Connection pad 116 ... Connection pattern 117 ... Ground via conductor 118 ... Conductive pattern for sealing 119 ... Measurement pad 120 ... Quartz element 121 ... Quartz element plate 122 ... Excitation electrode 123 ... Extraction electrode 130 ... Cover 131 ... Sealing member 140 ... conductive adhesive 150 ... integrated circuit element 151 ... connecting terminal 160 ... mounting frame 161 ... bonding pad 162 ... external terminal 163 ... conductor portion 170 ... Conductive bonding material 180 ... Insulating resin K1 ... First recess K2 ... Second recess H ... Gap

Claims (4)

A substrate having a rectangular shape in plan view and provided with joining terminals having predetermined thicknesses at four corners of the lower surface;
A bonding frame having a predetermined thickness provided at the four corners of the upper surface, and a mounting frame provided on the lower surface of the substrate by bonding the bonding pad and the bonding terminal;
A crystal element mounted on a pair of electrode pads provided on the upper surface of the substrate;
An integrated circuit element having temperature sensors mounted on a plurality of connection pads provided in a region surrounded by the mounting frame on the lower surface of the substrate;
A lid for hermetically sealing the crystal element;
A wiring pattern electrically connected to the electrode pad and provided on the upper surface of the substrate;
A measurement pad provided on the lower surface of the substrate;
A via conductor electrically connected to the wiring pattern and the measurement pad and provided on the substrate;
With
From the area surrounded by the mounting frame on the lower surface of the substrate, between the two adjacent bonding pads and the bonding terminals, on the outer surface of the substrate and the mounting frame have a gap throughout,
The temperature-compensated crystal oscillator , wherein the via conductor is provided at a position overlapping the mounting frame body in plan view . The temperature compensated crystal oscillator according to claim 1,
The temperature-compensated crystal oscillator, wherein the mounting frame is made of glass epoxy resin. The temperature-compensated crystal oscillator according to claim 1 or 2 ,
A temperature compensated crystal oscillator, wherein an insulating resin is provided between the integrated circuit element and the connection pad. The temperature compensated crystal oscillator according to claim 3 , wherein
The temperature-compensated crystal oscillator, wherein the insulating resin is provided so as to block a lower surface exposed portion of the via conductor on the lower surface of the substrate.

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