JP2018164128A - Method for manufacturing crystal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a crystal device with which a short circuit between extraction electrodes due to a foreign substance can be detected.SOLUTION: A method for manufacturing a crystal device includes: a package preparation step of preparing a package 110 formed of a substrate 110a and a frame body 110b provided along an outer peripheral edge of the substrate 110a; a crystal element mounting step of mounting a crystal element 120 on an electrode pad 111 provided on the top face of the substrate 110a; a lid body joining step of joining a lid body 130 to the frame body 110b; a current value measuring step of applying voltage to an external terminal 112 provided on the undersurface of the substrate 110a to measure a current value; and a determination step of determining quality from the current value measured in the current value measuring step.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for manufacturing a crystal device used in, for example, an electronic apparatus.

  In addition, a conventional crystal device manufacturing method includes a crystal element mounting process for mounting a crystal element on a package with a conductive adhesive, and a lid and a package for bonding the crystal element so as to hermetically seal the crystal element. What is included by a lid joining process is known (for example, refer to reference 1).

JP 2007-104264 A

  In the above-described crystal device manufacturing method, foreign matter may adhere to the crystal element, and there is a possibility that the foreign substance may repeatedly cause a short circuit between the extraction electrodes and oscillation of the crystal element.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a method of manufacturing a quartz device capable of detecting a short circuit between extraction electrodes due to a foreign substance.

  A method of manufacturing a quartz crystal device according to an aspect of the present invention includes a package preparation step of preparing a package configured by a substrate and a frame body provided along an outer peripheral edge of the substrate, and a top surface of the substrate. A crystal element mounting process for mounting a crystal element on an electrode pad, a lid bonding process for bonding a lid to a frame, and a current value for measuring a current value by applying a voltage to an external terminal provided on the lower surface of the substrate It includes a determination step for determining pass / fail according to the measurement step and the current value measured in the current value measurement step.

  A method of manufacturing a quartz crystal device according to an aspect of the present invention includes a package preparation step of preparing a package configured by a substrate and a frame body provided along an outer peripheral edge of the substrate, and a top surface of the substrate. A crystal element mounting process for mounting a crystal element on an electrode pad, a lid bonding process for bonding a lid to a frame, and a current value for measuring a current value by applying a voltage to an external terminal provided on the lower surface of the substrate It includes a determination step for determining pass / fail according to the measurement step and the current value measured in the current value measurement step. By doing so, defective products and non-defective products tend to have a large change in current value at high voltage, and by determining the current value at the voltage, the lead electrode of the crystal element due to foreign matter adhering to the crystal element A short circuit can be detected. Therefore, it is possible to improve the productivity of the crystal device.

It is a disassembled perspective view of the crystal device which concerns on this embodiment. It is sectional drawing of the crystal device which concerns on this embodiment. (A) It is sectional drawing which shows the crystal element mounting process in the manufacturing method of the quartz crystal device concerning this embodiment, (b) It is sectional drawing which shows the cover body process in the manufacturing method of the quartz crystal device concerning this embodiment, c) It is sectional drawing which shows the electric current value measurement process in the manufacturing method of the crystal device which concerns on this embodiment. It is a graph which shows the relationship between the voltage and electric current value in the electric current value measurement process in the manufacturing method of the crystal device which concerns on this embodiment. It is a graph which shows the relationship between the electric current value in the electric current value measurement process in the manufacturing method of the crystal device which concerns on this embodiment, and the inclination of an electric current value. It is a top view which shows the tuning fork type | mold crystal element formed at the tuning fork type | mold crystal element formation process in the manufacturing method of the crystal device which concerns on the modification of this embodiment.

  The crystal device in this embodiment includes a package 110 and a tuning fork type crystal element 120 mounted on the upper surface of the package 110 as shown in FIGS. The package 110 has a recess K1 surrounded by the upper surface of the substrate 110a and the inner surface of the frame 110b. A crystal element 120 is mounted on the electrode pad 111 on the upper surface of the substrate 110a. Such a crystal device is used to output a reference signal used in an electronic device or the like.

  The substrate 110a has a rectangular shape for mounting the crystal element 120 on the upper surface. A pair of electrode pads 111 for mounting the crystal element 120 is provided on the upper surface of the substrate 110a.

  In addition, external terminals 112 are provided at the four corners of the lower surface of the substrate 110a. Two of the four external terminals 112 are electrically connected to the crystal element 120. In addition, the pair of external terminals 112 that are electrically connected to the crystal element 120 are provided so as to be positioned diagonally on the lower surface of the substrate 110a.

  The substrate 110a is made of an insulating layer made of a ceramic material such as alumina ceramic or glass-ceramic. The substrate 110a may be one using an insulating layer or may be a laminate of a plurality of insulating layers. A wiring pattern (not shown) for electrically connecting the electrode pads 111 provided on the upper surface of the frame 110b and the external terminals 112 provided on the lower surface of the substrate 110a on the surface and inside of the substrate 110a. And via conductors (not shown).

  The frame 110b is disposed on the upper surface of the substrate 110a, and is for forming the recess K1 on the upper surface of the substrate 110a. The frame 110b is made of a ceramic material such as alumina ceramics or glass-ceramics, and is formed integrally with the substrate 110a.

  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 110a, and are provided adjacent to each other along one side of the inner periphery of the substrate 110a inside the frame 110b.

  The external terminal 112 is used for bonding to a mounting pad (not shown) on an external mounting substrate such as an electric device. The external terminals 112 are provided at the four corners of the lower surface of the substrate 110a. The external terminal 112 includes a first external terminal 112a, a second external terminal 112b, a third external terminal 112c, and a fourth external terminal 112d. The third external terminal 112c is electrically connected to the sealing conductor pattern 117 via the third via conductor 114c. In addition, at least one of the external terminals 112 is connected to a mounting pad connected to a ground potential that is a reference potential on a mounting substrate such as an electronic device. As a result, the lid 130 bonded to the sealing conductor pattern 117 is connected to the third external terminal 112c having the ground potential. Therefore, the shielding performance in the recess K by the lid 130 is improved.

  The wiring pattern 113 is for electrically connecting the electrode pad 111 and the via conductor 114. The wiring pattern 113 includes a first wiring pattern 113a and a second wiring pattern 113b. One end of the first wiring pattern 113a is electrically connected to the first electrode pad 111a, and the other end of the first wiring pattern 113a is electrically connected to the first via conductor 114a. One end of the second wiring pattern 113b is electrically connected to the second electrode pad 111b, and the other end of the second wiring pattern 113b is electrically connected to the second via conductor 114b.

  Further, the wiring pattern 113 is provided so as to overlap the frame 110b in plan view. By doing so, the crystal device suppresses the generation of stray capacitance between the wiring pattern 113 and the crystal element 120, so that this stray capacitance is not added to the crystal element 120, and therefore the oscillation frequency Can be prevented from fluctuating. Further, even when an external force is applied to the crystal device and a bending moment is generated in the long side direction of the frame 110b, the frame 110b is provided in addition to the substrate 110a, so that the frame 110b is provided. Becomes difficult to deform. Therefore, the wiring pattern 113 provided at a position overlapping the frame 110b in plan view is less likely to be disconnected, and the oscillation frequency is not output.

  The first wiring pattern 113a is electrically connected to the first electrode pad 111a and the first via conductor 114a. The first wiring pattern 113a extends in the long side direction of the frame 110b adjacent to the first electrode pad 111a, and a part of the first wiring pattern 113a is exposed. The second wiring pattern 113b is electrically connected to the second electrode pad 111b and the second via conductor 114b. The second wiring pattern 113b extends in the long side direction of the frame 110b adjacent to the second electrode pad 111b, and a part of the second wiring pattern 113b is exposed.

  In this way, a part of the wiring pattern 113 is provided so as to extend from the electrode pad 111 toward the long side of the frame 110b and to be exposed in the recess K1, thereby mounting the crystal element 120. In this case, even if the conductive adhesive 140 overflows from the electrode pad 111, the conductive adhesive 140 easily flows along the conductive adhesive 140 and the wiring pattern 113 having good wettability. It is possible to prevent the conductive adhesive 140 from adhering to the excitation electrode 122 without flowing out in the direction.

  The via conductor 114 is for electrically connecting the external terminal 112 and the wiring pattern 113 or the sealing conductor pattern 117. Both ends of the via conductor 114 are connected to the external terminal 112 and the wiring pattern 113 or the sealing conductor pattern 117. The via conductor 114 includes a first via conductor 114a, a second via conductor 114b, and a third via conductor 114c. Thus, the external terminal 112 is electrically connected to the wiring pattern 113 or the sealing conductor pattern 117 through the via conductor 114.

  The sealing conductor pattern 117 plays a role of improving the wettability of the bonding member 131 when bonded to the lid 130 via the bonding member 131. The sealing conductor pattern 117 is electrically connected to the third external terminal 112c, which is at least one of the external terminals 112, via the third via conductor 114c. The sealing conductor pattern 117 is formed to have a thickness of, for example, 10 to 25 μm by sequentially applying nickel plating and gold plating on the surface of the conductor pattern made of, for example, tungsten or molybdenum in a form surrounding the upper surface of the frame 110b in an annular shape. Has been.

  Here, a method for manufacturing the package 110 will be described. When the substrate 110a and the frame 110b constituting the package 110 are 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, it is produced by applying nickel plating, gold plating, silver palladium, or the like to a predetermined portion of the conductor pattern, specifically, a portion to be the electrode pad 111, the external terminal 112, the wiring pattern 113, and the sealing conductor pattern 117. Is done. 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.

(Crystal element)
As shown in FIGS. 1 and 2, the crystal element 120 is mounted on the electrode pad 111 on the substrate 110a via the 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. As shown in FIG. 4, the crystal element 120 includes a crystal element plate 121, excitation electrodes 122 provided on the upper and lower surfaces of the crystal element plate 121, and lead electrodes provided along one side of the crystal element plate 121. 123. In addition, the crystal element 120 is integrally formed by a photolithography technique and an etching technique. The quartz base plate 121 has a substantially rectangular shape in plan view.

  The quartz base plate 121 is made of a piezoelectric material that performs stable mechanical vibration. For example, a quartz crystal member having a crystal axis composed of an X axis, a Y axis, and a Z axis that are orthogonal to each other is used. . At this time, the main surface of the quartz base plate 121 is a surface obtained by rotating a surface parallel to the X axis and the Z axis counterclockwise around the X axis as viewed in the negative direction of the X axis. It is parallel. For example, the main surface of the quartz base plate 121 is a surface parallel to the X axis and the Z axis rotated about 37 ° counterclockwise around the X axis as viewed in the negative direction of the X axis. It is parallel to the surface.

  Here, the Example of each dimension of the quartz base plate 121 is demonstrated. The crystal base plate 121 has a substantially rectangular shape in plan view, the long side dimension is 0.5 mm to 3.2 mm, and the short side dimension is 0.2 mm to 2.5 mm. It has become.

  The excitation electrode 122 and the extraction electrode 123 provided on the crystal base plate 121 are for applying a voltage from the outside of the crystal base plate 121. The excitation electrode 122 and the extraction electrode 123 are not particularly illustrated, but include, for example, a first metal layer and a second metal layer laminated on the first metal layer. For the first metal layer, a metal having good adhesion to quartz is used, and for example, any one of nickel, chromium, nichrome, or titanium is used. By using a metal having good adhesion to the crystal, even a metal material that is difficult to adhere to the crystal can be used for the second metal layer. The second metal layer is made of a stable metal material having a relatively low electrical resistivity among the metal materials. For the second metal layer, for example, any one of gold, an alloy containing gold, silver, or an alloy containing silver is used. In this way, by using a metal material having a relatively low electrical resistivity among the metal materials, the excitation electrode 122 and the extraction electrode 123 can have their own electrical resistivity reduced. As a result, the crystal element An increase in the equivalent series resistance value of 120 can be reduced. In addition, by using a stable metal material in this way, it is oxidized with surrounding oxygen, and the weight of the excitation electrode 122 and the extraction electrode 123 changes accordingly, and the frequency of the crystal element 120 is reduced. It becomes possible to make it.

  The excitation electrode 122 (122a, 122b) is for applying a voltage to the crystal element 120. The excitation electrode 122 is a pair, and one excitation electrode 122 a is provided on the upper surface of the crystal base plate 121, and the other excitation electrode 122 b is provided on the lower surface of the crystal base plate 121. The excitation electrode 122 has a substantially rectangular shape in plan view of the crystal element 120.

  Here, a method of forming the excitation electrode 122 and the extraction electrode 123 will be described. Here, a case where the excitation electrode 122 and the extraction electrode 123 are integrally formed using a photolithography technique and an etching technique will be described as an example. First, a crystal wafer is prepared in a state where the portions to be the crystal base plate 121 are connected, and a metal film to be the excitation electrode 122 and the extraction electrode 123 is formed on both main surfaces of the crystal wafer. Next, a photosensitive resist is applied on the metal film, and exposed to a predetermined pattern and developed. At this time, after development, the photosensitive resist remains in portions that become the excitation electrode 122 and the extraction electrode 123, specifically, portions that become the excitation electrode 122 and the extraction electrode 123. Finally, the remaining photosensitive resist is removed, so that the excitation electrode 122 and the extraction electrode 123 are formed on the crystal base plate 121 of the crystal wafer. Note that the excitation electrode 122 and the extraction electrode 123 may be formed separately, or may be formed using a sputtering technique or an evaporation technique instead of a photolithography technique and an etching technique, or a photolithography technique and an etching technique. And a sputtering technique or a vapor deposition technique may be combined.

  The lid 130 is made of, for example, an Fe—Ni alloy (42 alloy), an Fe—Ni—Co alloy (Kovar), or the like. In such a lid 130, the recess K1 is hermetically sealed in a nitrogen atmosphere or a vacuum atmosphere. Specifically, the lid 130 is placed on the frame 110b of the package 110 in a nitrogen atmosphere or a vacuum atmosphere, and the surface of the sealing conductor pattern 117 provided on the upper surface of the frame 110b and the lid The seam welding is performed by applying a predetermined current so that the joining member 131 of the body 130 is melted, thereby joining the frame body 110b.

  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.

  The lid body 130 has a rectangular shape, and is for hermetically sealing the concave portion K1 in a vacuum state or the concave portion K filled with nitrogen gas or the like. Specifically, the lid 130 is placed on the upper surface of the sealing conductor pattern 117 provided on the frame 110b in a predetermined atmosphere. When heat is applied to the bonding member 131 provided on the lower surface of the lid body 130, the bonding member 131 is melt-bonded to the sealing conductor pattern 117. The lid 130 is made of an alloy containing at least one of iron, nickel, and cobalt, for example.

  The joining member 131 is provided from the upper surface of the sealing conductor pattern 117 of the frame body 110 b to the lower surface of the lid body 130. For example, in the case of glass, the joining member 131 is a glass that melts at 300 ° C. to 400 ° C., and is made of, for example, low-melting glass or lead oxide-based glass containing vanadium. Glass is in the form of a paste to which a binder and a solvent are added. After being melted, the glass is solidified and joined to another member. The joining member 131 is provided by, for example, applying glass frit paste by a screen printing method and drying. In addition, when the joining member 131 is printed on the upper surface of the frame 110b, the joining member 131 is printed on the entire circumference of the frame 110b so that the joining members 131 overlap the four corners of the frame 110b. Therefore, the thickness of the bonding member 131 at the four corners is provided to be thicker than the thickness of other portions where the bonding member 131 is provided. The composition of the lead oxide glass is composed of lead oxide, lead fluoride, titanium dioxide, niobium oxide, bismuth oxide, boron oxide, zinc oxide, ferric oxide, copper oxide and calcium oxide.

  For example, in the case of an insulating resin, the bonding member 131 is made of an epoxy resin or a polyimide resin. The thickness of the joining member 131 provided between the frame body 110b and the lid body 130 is 30 to 100 μm.

  For example, when the joining member 131 is gold tin, the thickness of the layer of the joining member 131 is 10 to 40 μm. For example, the component ratio is 70 to 80% for gold and 20 to 30% for tin. May be used. For example, when the joining member 131 is silver brazing, the thickness of the layer of the joining member 131 is 10 to 40 μm. For example, the component ratio is 70 to 80% for silver and 20 to 30% for copper. May be used.

(Production method)
The crystal device manufacturing method of the present embodiment includes a package preparation step of preparing a package 110 constituted by a substrate 110a and a frame 110b provided along the outer peripheral edge of the substrate 110a, and a method of providing the crystal device on the upper surface of the substrate 110a. A voltage is applied to the crystal element mounting process for mounting the crystal element 120 on the formed electrode pad 111, the lid bonding process for bonding the lid 130 to the frame 110b, and the external terminal 112 provided on the lower surface of the substrate 110a. The current value measuring step for measuring the current value and the determining step for determining the quality based on the current value measured by the current value measuring step are included.

(Package preparation process)
The package preparation process is a process of preparing the package 110 configured by the substrate 110a and the frame body 110b provided along the outer peripheral edge of the substrate 110a. The package preparation step is provided on the substrate 110a, the frame 110b provided along the outer peripheral edge of the upper surface of the substrate 110a, the pair of electrode pads 111 provided on the upper surface of the substrate 110a, and the lower surface of the substrate 110a. This is a step of preparing the package 110 in which the external terminal 112 is electrically connected.

(Quartz element formation process)
The crystal element forming step is provided along one side of the crystal element plate 121 with a space between the rectangular crystal element plate 121, the excitation electrodes 122 provided on the upper and lower surfaces of the crystal element plate 121, and the excitation electrode 122. In this step, the crystal element 120 having the pair of lead electrodes 123 is formed.

  First, a flat plate-like quartz wafer (not shown) having crystal axes which are composed of an X axis, a Y axis and a Z axis and which are orthogonal to each other is formed. As the quartz wafer, an artificial crystalline lens having crystal axes which are composed of an X axis, a Y axis and a Z axis and which are orthogonal to each other is used. The main surface of the quartz wafer is, for example, a plane parallel to the X-axis and the Z-axis, and a predetermined angle, for example, about 37, counterclockwise around the X-axis and viewing the negative direction of the X-axis. ° Parallel to the rotated surface. In addition, after the quartz wafer is cut from the artificial crystalline lens at a predetermined cut angle, both main surfaces are polished so that the thickness in the vertical direction is a predetermined thickness.

  Here, the quartz wafer has, for example, a substantially rectangular flat plate shape. When viewed in plan, the dimension of a predetermined side is 10.0 to 101.6 mm, and is connected to the predetermined side. The size of one side is 10.0 to 101.6 mm. At this time, the thickness of the quartz wafer in the vertical direction is 0.020 to 0.070 mm. In addition, although the case where the quartz wafer has a substantially rectangular flat plate shape has been described, it may be a circular plate shape or an elliptical flat plate shape. 0.0 to 101.6 mm.

  The crystal element plate 121 is fixed to a predetermined position of the crystal wafer at a predetermined one side of the main surface of the part that becomes the crystal element plate 121 by a photolithography technique and an etching technique, while the part of the crystal element plate 121 that becomes the crystal element plate 121 is fixed. A portion to be a quartz base plate 121 having an m-plane formed on a part of the side surface is formed. First, using a conventionally well-known photolithography technique, a metal film is deposited on the entire surface of both main surfaces of a quartz wafer, a resist is applied on the metal film, and a predetermined pattern is exposed and developed. Thereafter, etching is performed by immersing the quartz wafer in a predetermined etching solution using a conventionally known etching technique. At this time, by utilizing the fact that etching is performed differently depending on the axial direction of the crystal axis, an m-plane parallel to the Z-axis can be easily formed on a part of the side surface of the portion that becomes the crystal element plate 121.

  A metal film is deposited on the upper and lower surfaces of the quartz base plate 121 to form the excitation electrode 122 and the extraction electrode 123. When the excitation electrode 122 and the extraction electrode 123 are formed, the crystal wafer is mainly deposited by a vapor deposition technique or a sputtering technique in a state where the crystal wafer is placed between a pair of masks in which through holes having a predetermined pattern are formed. In a space formed by the surface and the surface facing the inside of the through hole, a metal film is deposited at a predetermined position of a portion to be the crystal base plate 121 of the crystal wafer.

  Finally, a predetermined one side of the main surface of the portion that becomes the crystal base plate 121 is folded or cut, and the portion that becomes the crystal base plate 121 is separated into pieces. In the quartz wafer, a portion that becomes the quartz base plate 121 on which the excitation electrode 122 and the extraction electrode 123 are formed is fixed on a predetermined one side of the main surface of the portion that becomes the quartz base plate 121. The crystal element 120 is formed by folding or cutting the fixed portion.

(Crystal element mounting process)
The crystal element mounting step is a step of mounting the crystal element 120 on the electrode pad 111 provided on the upper surface of the substrate 110a. First, the conductive adhesive 140 is applied on the electrode pad 111 provided on the package 110. A nozzle (not shown) that adsorbs the crystal element 120 is moved in accordance with the position of the conductive adhesive 140, and the outer peripheral edge of the conductive adhesive 140 applied to the electrode pad 111 is pulled out of the crystal element 120. The crystal element 120 is placed on the conductive adhesive 140 so as to be positioned on the electrode 123. The crystal element 120 is placed on the conductive adhesive 140 so that the lead electrode 123 of the crystal element 120 and the conductive adhesive 140 applied on the electrode pad 111 of the package 110 face each other. Next, in a state where the package 110 is housed in the internal space of the curing annealing furnace in the air atmosphere or nitrogen atmosphere, the conductive adhesive 140 is heated and cured, and the electrode pad 111 and the crystal element 120 are conductively fixed.

  A curing annealing furnace (not shown) includes a furnace body, a heating unit, a supply unit, and a control unit. The furnace body has an internal space and serves to store the package 110. The heating unit plays a role of heating the internal space to a predetermined temperature. For example, a halogen lamp or a xenon lamp is used as the heating unit. The supply unit serves to supply gas to the internal space. For example, nitrogen is used as the gas. The control unit controls the temperature and oxygen concentration of the internal space of the furnace body, the temperature increase rate of the heating unit, and the gas supply amount of the supply unit.

(Current value measurement process)
The current value measuring step is a step of measuring a current value by applying a voltage to the external terminal 112 provided on the lower surface of the substrate 110a. Of the external terminals 112 provided on the lower surface of the substrate 110a, a probe connected to a measuring instrument (not shown) to two external terminals 112 electrically connected to the electrode pad 111 on which the crystal element 120 is mounted. By contacting 160, the current value between the two external terminals 112 is measured while applying a voltage.

Such a current value is measured between -5 (V) and 50 (V). For example, as shown in FIG. 4, the measured value of the defective product 1 that is a short-circuited crystal device has a current value at −5 (V) as 1.0 × 10 ⁻¹³ (A The current value at the time of 9 (V) is 8.1 × 10 ⁻¹² (A). Further, as shown in FIG. 4, when the defective product 2 that is a short-circuited crystal device is measured, the current value at −5 (V) is 1.0 × 10 ⁻¹³ (A ), And the current value at 30 (V) is 8.1 × 10 ⁻¹² (A). Further, as shown in FIG. 4, when the defective product 3 which is a short-circuited crystal device is measured, the current value at the time of −5 (V) is 1.0 × 10 ⁻¹³ (A The current value at the time of 50 (V) is 3.1 × 10 ⁻¹² (A).

As shown in FIG. 4, the measured value of the non-defective crystal device 1 that is not short-circuited is 1.0 × 10 ⁻¹³ (A) at the time of −5 (V), and 50 The current value at time (V) is 1.1 × 10 ⁻¹² (A).

  Also, measuring the current value after applying a voltage in the range of 0 to 35 (V) can suppress variations in the current value compared to measuring the current value at a high voltage. Therefore, since the measurement can be performed stably, it can be determined with higher accuracy in the determination step described later.

(Distinction process)
The determination step is a step of determining pass / fail based on the current value measured in the current value measurement step. This determination step determines whether the current value I1 with 35 (V) applied satisfies I1 <2.5 × 10 ⁻¹² (A).

Further, as shown in FIG. 4, the current value I1 of the defective product 1 with 9 (V) applied is 8.1 × 10 ⁻¹² (A). Therefore, since the current value I1 when 35 (V) is applied is 8.1 × 10 ⁻¹² (A) or more, the conditional expression is not satisfied and the current value I1 can be separated from the defective product. Can be confirmed. Moreover, as shown in FIG. 4, the current value I1 of the defective product 2 with 30 (V) applied is 8.1 × 10 ⁻¹² (A). Therefore, since the current value I1 when 35 (V) is applied is 8.1 × 10 ⁻¹² (A) or more, the conditional expression is not satisfied and the current value I1 can be separated from the defective product. Can be confirmed. Further, as shown in FIG. 4, the current value I1 of the defective product 3 when 35 (V) is applied is 3.1 × 10 ⁻¹² (A). Therefore, it can be confirmed that the current value I1 in a state where 35 (V) is applied does not satisfy the conditional expression and can be separated from the defective product. Thus, since the current value I1 from the defective product 1 to the defective product 3 is larger than 2.5 × 10 ⁻¹² (A), it can be proved that the current product is correctly classified.

Moreover, as shown in FIG. 4, the current value in the state which applied 35 (V) of the good product 1 is 0.2 * 10 < ^-13 > (A) or more. Therefore, it can be confirmed that the current value I1 when 35 (V) is applied satisfies the conditional expression and can be separated from non-defective products. That is, since the non-defective product is smaller than 2.5 × 10 ⁻¹² (A), it can be proved that the product is correctly sorted. By determining the current value in this way, it is possible to detect a short circuit between the extraction electrodes of the crystal element due to foreign matter adhering to the crystal element. Therefore, it is possible to improve the productivity of the crystal device.

Further, in the determination step, the current value of each voltage in the range of −5 to 50 (V) is measured, an approximate line is derived from the current value, and the slope A1 of the approximate line is calculated. Next, whether the approximation straight line has an inclination A1 satisfies A1 ≦ 2.0 × 10 ⁻¹⁴ or not is determined. The inclination A1 of the approximate straight line L1 of the defective product 1 is 3.0 × 10 ⁻¹³ . The inclination A2 of the approximate straight line L2 of the defective product 2 is 2.0 × 10 ⁻¹³ . Further, the inclination A1 of the approximate straight line L3 of the defective product 3 is 3.0 × 10 ⁻¹³ . As a result, the slope A1 of the approximate straight line from the defective product 1 to the defective product 3 is larger than 2.0 × 10 ⁻¹⁴ , so that the conditional expression is not satisfied and the defective product is accurately classified as a defective product. I can prove that. Further, the inclination A1 of the approximate straight line L4 of the non-defective product 1 is 1.0 × 10 ⁻¹⁴ . Thereby, since the inclination A1 of the approximate straight line L4 of the non-defective product 1 is smaller than 2.0 × 10 ⁻¹⁴ , the conditional expression is satisfied, and it can be proved that the non-defective product is correctly classified. .

FIG. 5 is a graph in which 20 defective products and 30 non-defective products are plotted with current values in a state where a voltage of 35 (V) is applied and the slope of an approximate straight line of the current values. When this plot is confirmed, the non-defective product and the defective product are separated by the conditional expression of I1 <2.5 × 10 ⁻¹² (A) and A1 ≦ 2.0 × 10 ⁻¹⁴ which are the conditional expressions of the present invention. It has been proven. Thus, in the determination step, the current value I1 with 35 (V) applied satisfies I1 <2.5 × 10 ⁻¹² (A), and the slope A1 of the approximate straight line of the current value is A1 ≦ 2. By satisfying 0.0 × 10 ⁻¹⁴ , as shown in FIG. 5, it is possible to further improve the detection accuracy of the short circuit between the lead electrodes 123 of the crystal element 120 due to foreign matter adhering to the crystal element 120. it can. Therefore, it becomes possible to further improve the productivity of the crystal device.

  A method of manufacturing a quartz crystal device according to an aspect of the present invention includes a package preparation step of preparing a package 110 including a substrate 110a and a frame 110b provided along the outer peripheral edge of the substrate 110a, A crystal element mounting process for mounting the crystal element 120 on the electrode pad 111 provided on the upper surface, a lid bonding process for bonding the lid 130 to the frame 110b, and a voltage applied to the external terminal 112 provided on the lower surface of the substrate. A current value measuring step of applying and measuring a current value, and a determining step of determining pass / fail according to the current value measured by the current value measuring step. By doing so, the difference between a defective product and a non-defective product tends to have a large change in current value at a high voltage. By judging the current value from the voltage, the crystal due to foreign matter adhering to the crystal element A short circuit between the lead electrodes of the element can be detected. Therefore, it is possible to improve the productivity of the crystal device.

  Further, in the method for manufacturing a crystal device according to the present embodiment, in the current value measurement step, the voltage value applied to the external terminal 112 is between −5 to 50 (V) and the voltage is applied every 5 (V). Then, the current value at the voltage is measured. By measuring the current values at a plurality of points, it is possible to detect a short circuit between the extraction electrodes 113 of the crystal element 120 due to foreign matters adhering to the crystal element 120 with higher accuracy.

  Further, in the method for manufacturing a crystal device according to the present embodiment, the crystal element 122 includes a substantially rectangular crystal element plate 121, excitation electrodes 122 provided on both main surfaces of the crystal element plate 121, and excitation electrodes 122. And a crystal element forming step of forming the crystal element 120 by providing an electrically connected lead electrode 123. By forming such a crystal element 120, it is possible to provide a crystal device mounted with the crystal element 120 capable of efficiently confining vibration energy and reducing the CI value.

In the method of manufacturing a quartz crystal device according to one aspect of the present invention, in the determination step, the current value of each voltage in the range of 0 to 35 (V) is measured, and the slope A1 of the approximate expression is calculated. Next, it is determined whether or not the slope A1 of the approximate expression satisfies A1 ≦ 2.0 × 10 ⁻¹⁴ . By doing so, defective products and non-defective products tend to have a large change in current value at a high voltage, and the crystal element due to foreign matter adhering to the crystal element 120 by determining the slope of the current value in voltage. A short circuit between the 120 extraction electrodes 123 can be detected with higher accuracy. Therefore, it becomes possible to further improve the productivity of the crystal device.

(Modification)
In the crystal device manufacturing method according to the modification of the present embodiment, the crystal element constituting the crystal device is the tuning fork type crystal element 220 as shown in FIG. 6, and the crystal element forming process is changed to the tuning fork type crystal element forming process. Is different.

(Tuning fork type crystal element forming process)
The tuning-fork type crystal element forming step includes a substantially rectangular crystal base portion 221 and a crystal vibration portion 223 that is provided so as to extend from the side surface of the crystal base portion 221 and is constituted by a vibrating arm portion 222 and a weight portion 228. A crystal piece is formed, and excitation electrodes 225 and 226 are provided on the upper surface, the lower surface, and the side surface of the vibrating arm portion 222, and the lead is provided from the crystal vibration portion 223 to the crystal base portion 221 and is electrically connected to the excitation electrodes 225 and 226. The electrode 227 is provided, and the tuning fork type crystal element 220 is formed.

  To form a crystal piece, a crystal wafer forming process, a corrosion resistant film forming process, a first resist film forming process, a first exposure developing process, a first corrosion resistant film etching process, a second resist film forming process, and a second exposure developing process A crystal etching step and a second corrosion-resistant film etching step.

  First, the crystal wafer forming step is a step of forming a crystal wafer from a crystal member having crystal axes composed of an X axis, a Y axis, and a Z axis that are orthogonal to each other. In the quartz wafer forming step, when the lumbard artificial quartz is cut at a predetermined cut angle, it is polished until the thickness in the vertical direction becomes a predetermined thickness. In the quartz wafer after the quartz wafer forming step, two opposing faces are parallel to a plane obtained by rotating a plane parallel to the X axis and the Y axis by -5 ° to 5 ° around the X axis. .

  The corrosion resistant film forming step is a step of providing a corrosion resistant film on both main surfaces of the quartz wafer. Here, the main surface of the quartz wafer is defined as a surface parallel to a surface parallel to the X axis and the Y axis and rotated from −5 ° to 5 ° about the X axis. In the corrosion resistant film forming process, a metal film made of a material that is not etched in the crystal etching process is applied to both main surfaces of the crystal wafer by a sputtering technique or a vapor deposition technique. For example, chromium is used for the corrosion resistant film. In addition, although chromium is mentioned here as an example of a corrosion-resistant film | membrane, it has gold, silver, palladium, and gold as a main component on the metal layer selected from chromium, titanium, nichrome, or nickel. A laminated structure in which a metal layer selected from any one of a metal, a metal containing silver as a main component, and a metal containing palladium as a main component may be provided.

  The first resist film forming step is a step of applying the first resist to the quartz wafer on which the corrosion resistant film is formed. The first exposure / development step is a step of exposing and developing the crystal wafer coated with the first resist in a predetermined pattern. When the crystal wafer after the first exposure and development process is viewed in plan, the corrosion-resistant film is exposed along the portion that becomes the groove 228 and the outer peripheral edge of the crystal piece. The first corrosion-resistant film etching process is a process of etching the exposed corrosion-resistant film on the quartz wafer after the first exposure and development process. Accordingly, when the crystal wafer after the first corrosion-resistant film etching process is viewed in plan, the crystal wafer is exposed along the groove portion and the outer peripheral edge of the crystal piece. At this time, the first resist is also removed.

  The second resist film forming step is a step of applying the second resist to the crystal wafer after the first corrosion-resistant film etching step. The second exposure and development step is a step of exposing and developing the quartz wafer coated with the second resist into a predetermined pattern. When the crystal wafer after the second exposure and development process is viewed in plan, the portions that become the excitation electrodes 225 and 226 and the extraction electrode 227 are in a state where the corrosion-resistant film is exposed.

  The crystal etching process is a process of immersing the crystal wafer after the second exposure development process in a predetermined etching solution to etch the exposed crystal wafer. The second corrosion resistant film etching step is a step of etching away the exposed corrosion resistant film. When the crystal wafer in the second exposure and development process is viewed in plan, the portions of the anticorrosion film that become the excitation electrodes 225 and 226 and the extraction electrode 227 are exposed. Then, the portions of the quartz that become the excitation electrodes 225 and 226 and the extraction electrode 227 are exposed. Moreover, the part used as the side surface of a crystal piece is the state exposed.

 First, a metal film is formed on the quartz wafer after the second corrosion-resistant film etching step. In the first electrode forming process, a sputtering technique or a vapor deposition technique is used, and a metal mainly composed of gold, silver, palladium, and gold is formed on a metal layer selected from any one of chromium, titanium, nichrome, and nickel. A metal film having a laminated structure in which a metal layer selected from one of a metal containing silver as a main component and a metal containing palladium as a main component is laminated is applied to an exposed portion of a quartz wafer. The The second resist removing step is a step of removing the second resist from the crystal wafer. The anti-corrosion film removing step is a step of removing the anti-corrosion film.

  In the method for manufacturing a crystal device according to the modification of the present embodiment, the crystal element 220 is provided so as to extend from the substantially rectangular crystal base 221 and the side surface of the crystal base 221, and the vibrating arm unit 222 and the weight unit A crystal piece having a crystal vibrating part 223 constituted by 228 is formed, excitation electrodes 225 and 226 are provided on the upper surface, the lower surface and the side surface of the vibrating arm part 222 and provided from the crystal vibrating part 223 to the crystal base part 221 and excited. A tuning fork type crystal element forming step of providing a lead electrode 227 electrically connected to the electrodes 225 and 226 and forming the tuning fork type crystal element 220. When such a tuning fork type crystal element 220 is mounted, the difference between a defective product and a non-defective product tends to have a larger change in current value at a high voltage, and the tuning fork is determined by determining the current value from the voltage. It is possible to detect a short circuit between the excitation electrodes 225 and 226 and the extraction electrode 227 of the tuning fork type crystal element 220 due to foreign matter adhering to the type crystal element 220. Therefore, it becomes possible to further improve the productivity of the crystal device.

  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 the frame 110b is integrally formed of a ceramic material in the same manner as the substrate 110a has been described. However, the frame 110b may be made of metal. In this case, the frame is joined to the conductor film of the substrate via a brazing material such as silver-copper.

  In the crystal device manufacturing method according to this embodiment, the package preparation process, the crystal element formation process, the crystal element mounting process, the current value measurement process, and the determination process are described in this order. You may manufacture in order of an element mounting process, an electric current value measurement process, and a discrimination | determination process. Even with such a method for manufacturing a quartz device, the same effects as in the present embodiment can be obtained.

DESCRIPTION OF SYMBOLS 110 ... Package 110a ... Board | substrate 110b ... Frame 111 ... Electrode pad 112 ... External terminal 117 ... Conductive pattern 120 for sealing 120, 220 ... Crystal element (Tuning fork type crystal element )
121 ... crystal base plate 221 ... crystal base 222 ... vibrating arm 223 ... crystal vibrating part 122,225,226 ... excitation electrode 123,227 ... extraction electrode 228 ... weight Part 229 ... Frequency adjusting electrode 130 ... Lid 131 ... Joining member 140 ... Conductive adhesive K1 ... Recess

Claims (4)

A package preparation step of preparing a package constituted by a substrate and a frame provided along an outer peripheral edge of the substrate;
A crystal element mounting step of mounting a crystal element on an electrode pad provided on the upper surface of the substrate;
A lid joining step for joining the lid to the frame; and
A current value measuring step of applying a voltage to an external terminal provided on the lower surface of the substrate and measuring a current value;
A method of manufacturing a crystal device, comprising a determination step of determining pass / fail according to the current value measured in the current value measurement step A method for producing a crystal device according to claim 1,
In the current value measuring step, the current value at the voltage is measured in a state where the voltage value applied to the external terminal is between -5 to 50 (V) every 5 (V). Method for manufacturing quartz device A method for producing a crystal device according to claim 1,
The crystal element is provided by providing a substantially rectangular crystal base plate, excitation electrodes provided on both main surfaces of the crystal base plate, and lead electrodes electrically connected to the excitation electrodes. And a crystal element forming step of forming a crystal device. A method for producing a crystal device according to claim 1,
The quartz crystal element is provided so as to extend from a side surface of the substantially rectangular quartz crystal base and the crystal base, and forms a crystal piece having a crystal vibrating part constituted by a vibrating arm part and a weight part, A tuning fork crystal element is formed by providing an excitation electrode on the upper surface, lower surface and side surface of the vibrating arm, and an extraction electrode provided from the crystal vibrating portion to the crystal base and electrically connected to the excitation electrode. And a tuning-fork type crystal element forming step.

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