JP5826113B2 - Piezoelectric vibration element storage package, piezoelectric device, and multi-piece wiring board - Google Patents

Description

  The present invention relates to a piezoelectric vibration element housing package in which piezoelectric vibration elements are housed in an airtight manner, a piezoelectric device, and a multi-cavity wiring board in which a plurality of regions to be a piezoelectric vibration element housing package are arranged on a mother board. It is.

  Conventionally, a package for accommodating a piezoelectric vibration element used for hermetically sealing the piezoelectric vibration element has a concave mounting portion for accommodating the piezoelectric vibration element on an upper surface of an insulating substrate made of a ceramic sintered body or the like. ing.

  The mounting portion is hermetically sealed by bonding the lid to the insulating substrate. The lid is made of glass, metal, or the like, and is bonded to the insulating substrate by a heating means such as an electric furnace using a sealing material such as silver solder or low-melting glass.

  The piezoelectric vibration element storage package is provided with a through-hole (gas exhaust hole) penetrating from the mounting portion to the lower surface of the insulating substrate in order to remove gas or the like generated when the lid is joined. There is something.

  After the piezoelectric vibration element is accommodated in the mounting portion, the lid is bonded to the upper surface of the insulating substrate, and then the gas is discharged from the gas discharge hole to the outside, and then the hole is closed with a sealing material such as a brazing material. It is peeled off and hermetically sealed.

  Such a piezoelectric vibration element storage package is generally in the form of a so-called multi-cavity wiring board in which a plurality of regions each serving as a piezoelectric vibration element storage package are arranged on a single large-area mother board. It has been produced. Divided grooves are formed in advance on the mother board along the boundaries of the regions, and the mother board is divided (broken) along the divided grooves, so that a plurality of regions (individual piezoelectric vibration element storage packages) are separated into pieces. It is divided into.

  In recent years, with the miniaturization of piezoelectric devices, the outer shape of a piezoelectric vibration element housing package for accommodating a piezoelectric vibration element has become smaller.

JP 2005-229340

  However, when the gas discharge hole is formed in the insulating substrate of the miniaturized piezoelectric vibration element storage package, the gas discharge hole is very small. Therefore, the size of a sealing material such as a brazing material inserted into the hole is also reduced. When the sealing material is small, it tends to be difficult to improve the reliability of hermetic sealing in the hole portion. That is, the volume of the sealing material may vary in the manufacturing process, and the degree of relative variation tends to increase with a decrease in the size of the sealing material, that is, the absolute volume. Therefore, it has become difficult for the sealing material to stably secure a volume sufficient to fill the gas discharge holes.

  The present invention has been devised in view of such problems, and an object of the present invention is to provide a piezoelectric device having a gas discharge hole and having a high reliability of hermetic sealing even in the case of downsizing, for example. And a piezoelectric device, and a multi-piece wiring board having a plurality of regions to be the piezoelectric vibration element storage package.

  According to another aspect of the present invention, there is provided a package for housing a piezoelectric vibration element, comprising: a flat base having an upper surface including a portion on which the piezoelectric vibration element is mounted; and a portion on which the piezoelectric vibration element is mounted on the upper surface of the base. A package for housing a piezoelectric vibration element including a frame portion surrounded and stacked, and a groove portion is provided on a side surface of the base portion from an upper end to a lower end of the side surface, and a part of the upper end of the groove portion is A first metallization layer is provided on the inner side of the groove part, and a second metallization layer is provided on the lower surface of the frame part exposed on the inner side of the groove part. The sealing member is bonded to the first metallized layer and the second metallized layer, and the groove is closed.

  A piezoelectric device according to one aspect of the present invention includes the above-described piezoelectric vibration element storage package, a piezoelectric vibration element mounted on the upper surface of the base, a lid bonded to the frame, and the first And a sealing material bonded to the metallized layer and the second metallized layer to close the groove.

  A multi-cavity wiring board according to one aspect of the present invention is a mother board comprising a flat lower insulating layer and an upper insulating layer having a plurality of openings and stacked on the upper surface of the lower insulating layer. A plurality of wiring substrate regions arranged in a plurality of wiring substrate regions, wherein each of the plurality of wiring substrate regions surrounds the opening, and the lower portion extends across the boundary of the wiring substrate region A through hole is formed in the insulating layer, a part of the upper end of the through hole is located inside the inner periphery of the opening, and a first metallized layer is formed on the inner surface of the through hole. And a second metallized layer is formed on the lower surface of the upper insulating layer exposed in the through hole.

  According to the piezoelectric vibration element housing package of one aspect of the present invention, the sealing material is bonded to the first metallized layer and the second metallized layer in the groove opened on the side surface of the base, and the groove is blocked. The sealing material can be easily inserted into the groove. Therefore, the volume of the sealing material can be secured even in a miniaturized wiring board. Therefore, it is possible to provide a package for accommodating a piezoelectric vibration element capable of manufacturing a piezoelectric device with high hermetic sealing reliability.

  According to the piezoelectric device of one aspect of the present invention, the piezoelectric vibration element storage package having the above configuration, the piezoelectric vibration element mounted on the upper surface of the base, the lid joined on the frame portion, and the groove portion are closed. Therefore, the volume of the sealing material that closes the groove can be easily secured. Therefore, for example, a piezoelectric device with high reliability of hermetic sealing can be provided even if the device is downsized.

  According to the multi-cavity wiring board of one aspect of the present invention, the through hole is formed in the lower insulating layer so as to straddle the boundary of the wiring board region, and a part of the upper end of the through hole is the inner periphery of the opening. Since the first metallized layer is formed on the inner side surface of the through hole and the second metallized layer is formed on the lower surface of the upper insulating layer exposed in the through hole, The piezoelectric vibration element storage package having the above-described configuration can be easily obtained by dividing along the line.

(A) is a top view of the piezoelectric vibration element accommodation package and piezoelectric device of embodiment of this invention, (b) is sectional drawing in the A-A 'line of (a). It is the perspective view which looked at the piezoelectric vibration element accommodation package of the embodiment of the present invention from the lower surface side. (A) is a top view of the multi-piece wiring board of embodiment of this invention, (b) is sectional drawing in the B-B 'line | wire of (a). (A) is a top view which shows the modification of the multi-piece wiring board of embodiment of this invention, (b) is sectional drawing in the C-C 'line of (a).

A piezoelectric vibration element storage package and a piezoelectric device according to the present invention will be described with reference to the accompanying drawings. FIG. 1A is a plan view showing a piezoelectric vibration element housing package and a piezoelectric device according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line AA ′ of FIG. . FIG. 2 is a perspective view of the piezoelectric vibration element storage package and the piezoelectric device according to the embodiment of the present invention as seen from the lower surface side. 1 and 2, reference numeral 101 denotes an insulating substrate, 102 denotes a base, 103 denotes a frame, 104 denotes a mounting portion, 105 denotes a piezoelectric vibration element, 106 denotes a groove, 107 denotes a first metallized layer, and 108 denotes a second layer.
The metallized layer 109 is a sealing material, 110 is a wiring conductor, 111 is a frame-like metallized layer, 112 is a castellation, and 113 is a lid.

A wiring conductor 110, a frame-like metallized layer 111, a groove 106, a first metallized layer 107, and a second metallized layer 108 are disposed on the insulating base 101, and thus a piezoelectric vibration element housing package is basically configured. The piezoelectric vibration element 105 is hermetically sealed in the piezoelectric vibration element storage package to form a piezoelectric device. In FIG. 1A, the lid 113 is omitted for easy viewing.

  The insulating base 101 is formed by laminating a frame 103 on a flat base 102. A concave mounting portion 104 for accommodating and mounting the piezoelectric vibration element 105 is formed by the inner side surface of the frame portion 103 and the upper surface of the base portion 102 exposed inside the inner side surface.

The base 102 and the frame 103 are made of a ceramic material such as an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, or a glass-ceramic sintered body. For example, the base 102 and the frame 103 made of the same ceramic material are simultaneously fired to produce the insulating base 101.

  The insulating base 101 has, for example, a rectangular shape whose one side has a length of about 1.6 to 10 mm and a thickness of about 0.2 to 2 mm in plan view. The insulating base 101 has the concave mounting portion 104 as described above on its upper surface.

Such an insulating base 101 is an organic binder suitable for raw material powders such as aluminum oxide, silicon oxide, magnesium oxide, and calcium oxide if the base 102 and the frame 103 are both made of an aluminum oxide sintered body. In addition, the mixture is mixed with a solvent, a plasticizer, etc. to make a slurry, and this is formed into a sheet by a sheet forming method such as a doctor blade method or a roll calender method, thereby obtaining a plurality of ceramic green sheets. A part of the ceramic green sheet is appropriately punched and formed into a frame shape, and is laminated vertically so that the frame-shaped ceramic green sheet is positioned on the flat ceramic green sheet. Manufactured by firing at high temperature.

The insulating base 101 is a so-called multi-piece wiring board (FIG. 1) in which a plurality of wiring board regions (not shown in FIGS. 1 and 2), each of which becomes such an insulating base 101, are arranged vertically and horizontally on a mother board. 1 and 2 (not shown in FIG. 2), and this is cut at the boundary of the wiring board region and is divided into individual pieces.

In the present embodiment, a frame-like metallized layer 111 is formed on the upper surface of the insulating substrate 101 (frame portion 103). The frame-shaped metallized layer 111 surrounds the mounting portion 104, and a lid 113 is brazed to the frame-shaped metallized layer 111. Here, the lid 113 is not brazed directly to the frame-shaped metallized layer 111, but a metal frame (not shown) is brazed to the frame-shaped metallized layer 111, and then the lid 113 is joined to the metal frame. May be. The frame-like metallized layer 111 is for joining the lid body 113 and the metal frame body to the insulating base 101 by means such as brazing. After the piezoelectric vibration element 105 is accommodated in the mounting portion 104, the piezoelectric vibration element 105 is accommodated in a container composed of the lid body 113 and the insulating base 101 by bonding the lid body 113 to the upper surface of the frame-shaped metallized layer 111. Is done. Thereafter, as will be described later, the groove 106 is closed to form a piezoelectric device (a crystal oscillator or the like).

The frame-like metallized layer 111 is formed of a metal material such as tungsten, molybdenum, manganese, copper, or silver. The frame-shaped metallized layer 111 is formed by, for example, printing a paste of a metal material such as tungsten in a predetermined pattern on the upper surface of a ceramic green sheet serving as an insulating layer that constitutes the frame portion 103. It is formed by the method of simultaneous firing. This firing may be performed after the ceramic green sheet to be the frame portion 103 is laminated on the ceramic green sheet to be the base portion 102.

The frame-like metallized layer 111 is a nickel plating layer (not shown) having a thickness of about 1 to 20 μm on the exposed surface in order to prevent oxidative corrosion and improve the bonding strength of the brazing material (not shown). ) And a gold plating layer (not shown) having a thickness of about 0.1 to 2 μm are preferably sequentially deposited.

The lid 113 is made of a metal material such as an iron-nickel alloy or an iron-nickel-cobalt alloy, and the back of the lid 113 is made by rolling a brazing material such as silver brazing. For example, the lid 113 has a thickness of about 0.2 to 0.8 mm. As a method for brazing the lid 113 to the frame-like metallized layer 111, for example, a silver brazing (not shown) with a thickness of 20 to 50 μm is previously applied to the lower surface of the lid 113, and this silver An example is a method in which the lower surface on which the wax is deposited is placed on the frame-like metallized layer 111 and locally heated by seam welding or the like while being temporarily fixed with a jig or the like. By this method, the lid 113 can be firmly brazed to the frame-like metallized layer 111.

When the lid 113 is made of a ceramic material or a resin material, the lid 113 is bonded to the frame-like metallized layer 111 so that the lid 113 can be joined to the frame-like metallized layer 111 by a brazing method or a welding method. Metal layer for bonding (not shown) by methods such as metallization and plating
Is formed.

A brazing material (not shown) for joining the lid 113 made of metal to the frame-like metallized layer 111 is, for example, a silver brazing based on a silver-copper eutectic composition (for example, 71 to 73 mass% silver- 27-29 mass% copper, JIS name: BAg-8). In the case of BAg-8, the melting point is about 780 ° C. By using such a brazing material, the lid body 113 can be brazed to the frame-like metallized layer 111 in a heat treatment (reducing atmosphere) of about 800 to 850 ° C. This brazing material may be added with a metal element such as tin or zinc in order to adjust wettability, melting temperature, etc. according to the size, shape, application, etc. of the insulating base 101.

In the piezoelectric vibration element storage package and the piezoelectric device, the piezoelectric vibration element 105 in the mounting portion 104 is electrically connected to the wiring conductor 110 and is electrically connected to an external electric circuit via the wiring conductor 110 or the like. The That is, the wiring conductor 110 functions as a conductor for connecting an electrode (not shown) of the piezoelectric vibration element 105 housed in the mounting portion 104.

The wiring conductor 110 can be formed on the insulating base 101 by using the same material as that of the frame-like metallized layer 111, for example, by the same method. That is, a metal material such as tungsten is attached to the base portion 102 of the insulating base 101 by a method such as a metallizing method, and the wiring conductor 110 is formed. Similarly to the frame-like metallized layer 111, a plating layer (not shown) may be attached to the wiring conductor 110.

  Electrical connection of the piezoelectric vibrating element 105 to the wiring conductor 110 is performed by a conductive bonding material (not shown). The bonding material is a conductive adhesive to which conductive particles made of a conductive material such as silver are added.

An electrode (not shown) may be provided on the lower surface of the insulating substrate 101. The electrode is electrically connected to the wiring conductor 110 via a connection conductor (not shown) provided inside the insulating base 101, for example. In the piezoelectric device, the electrode is electrically connected to an external electric circuit (not shown) through a conductive connecting material such as solder or a conductive adhesive. Accordingly, the piezoelectric vibration element 105 is electrically connected to an external electric circuit via the wiring conductor 110 and the electrodes.

The base portion 102 is formed with a groove portion 106 penetrating from the lower surface to the upper surface of the base portion 102. The groove portion 106 is for enabling the exhaust from the mounting portion 104 to the outside when the mounting portion 104 is closed by the lid body 113. That is, the groove 106 functions as a hole for discharging the gas remaining in the mounting portion 104.

In order to suppress the influence on the vibration of the piezoelectric vibration element 105 in the mounting portion 104 in which the piezoelectric vibration element 105 is accommodated, it is preferable that the degree of vacuum is high. Therefore, the groove 106 is formed as a gas discharge hole as described above. Examples of the gas remaining in the mounting portion 104 include, for example, a gas generated by a heat treatment that cures a bonding material that connects the piezoelectric vibration element 105 to the wiring conductor 110, a gas in which moisture contained in the air is evaporated, and the like. Can be mentioned.

As described above, after the mounting portion 104 is closed by the lid body 113, the gas is exhausted from the mounting portion 104 through the groove 106. Thereafter, the groove 106 is closed with the sealing material 109. Thereby, a piezoelectric device in which the piezoelectric vibration element 105 is hermetically sealed in the mounting portion 104 with a high degree of vacuum is manufactured. The sealing material 109 will be described in detail later.

In the piezoelectric vibration element housing package of the above embodiment, a part of the upper end of the groove portion 106 is located inside the inner periphery of the frame portion 103. A first metallized layer 107 is provided on the inner surface of the groove 106, and a second metallized layer 108 is formed on the lower surface of the frame 103 exposed inside the groove 106.
Is provided. The first metallized layer 107 and the second metallized layer 108 are connected to each other at the boundary. The sealing material 109 is bonded to the first metallized layer 107 and the second metallized layer 108 to close the groove 106.

The first and second metallized layers 107 and 108 can be formed by the same method using the same metal material as that of the wiring conductor 110. A detailed method of forming the first and second metallized layers 107 and 108 will be described in detail later in the description of the multi-piece wiring board.

Since the sealing material 109 is bonded to the first metallized layer 107 and the second metallized layer 108 in the groove 106 opened on the side surface of the base 102 and the groove 106 is closed, for example, as shown in FIG. It is easy to insert the sealing material 109 therein. It can be seen that a groove 106 is provided on the side surface of the base 102 from the upper end to the lower end of the side surface.

As can be seen from FIG. 2, even when the wiring board is downsized, since the hole into which the sealing material 109 is inserted is formed as the groove portion 106, the sealing material 109 can be easily inserted. In other words, the opening of the hole in the conventional piezoelectric vibration element storage package (not shown) is only the lower end of the through hole penetrating the base. On the other hand, in the piezoelectric vibration element housing package of the above-described embodiment, the groove 106 is opened on the side surface of the base 102 over the entire length. Therefore, the opening into which the sealing material 109 is inserted is larger than the opening in the prior art. Therefore, the volume of the sealing material 109 can be secured even in a miniaturized wiring board. Note that a part of the upper end of the groove portion 106 is located inside the inner periphery of the frame portion 103. That is, the groove 106 opens into the mounting portion 104 at the upper end. Therefore, before being sealed with the sealing material 109, gas can be discharged from the mounting portion 104 to the outside through the groove portion 106 communicating from the lower surface of the base portion 102 to the outer peripheral side surface.

Similarly to the wiring conductor 110, a plating layer (not shown) such as nickel may be applied to the exposed surfaces of the first and second metallized layers 107 and 108. When the plating layer is applied, the bonding property (wetting property and the like) of the sealing material 109 to the first and second metallized layers 107 and 108 can be improved.

A method of sealing with the lid 113 and the sealing material 109 will be described in detail below. First, the piezoelectric vibration element storage package is turned upside down so that the lower surface of the insulating base 101 faces upward.
A sealing material 109 is put in the groove 106. The sealing material 109 is, for example, solder, silver solder, Au—Sn, Au
It is made of a low melting point metal such as Ge, that is, a brazing material. At the stage of insertion into the groove 106, the sealing material 109 is formed into a ball shape (spherical or the like). A ball-shaped sealing material 109 is put into the groove 106 and positioned on the lower surface of the frame 103, and then the sealing material 109 is irradiated with a laser beam. When the sealing material 109 is melted by the laser beam, the sealing material 109 is bonded to the first metallized layer 107 and the second metallized layer 108 in the groove 106 opened on the side surface of the base 102 to close the groove 106. .

Since the groove portion 106 is open on the outer peripheral side surface of the base portion 102, when the sealing material 109 is inserted into the groove portion 106 with the lower surface of the insulating base 101 facing upward, the groove portion 106 can be viewed from either the upward direction or the horizontal direction. But it is easy to insert.

The mounting portion 104 of the piezoelectric vibration element storage package is sealed, for example, in a vacuum chamber. A lid 113 is joined to the upper side of the insulating substrate 101 in the vacuum chamber. A piezoelectric vibration element 105 is accommodated in a space formed by the insulating base 101 and the lid 113. Thereafter, the insulating base 101 is accommodated upside down in the vacuum chamber, and the ball-shaped sealing material 119 is positioned at the bottom of the groove 106 as described above. Then, by evacuating the vacuum chamber, the remaining gas is discharged to the outside from the mounting portion 104 formed by the insulating base 101 and the lid 113. Therefore, the degree of vacuum in the mounting portion 104 can be increased and hermetically sealed.

Here, the positioning of the sealing material 109 in the groove portion 106 is performed by inclining the insulating base 101 so that the position of the opening side is slightly higher because the outer peripheral side surface side of the base portion 102 is open. After positioning the material 109 or arranging the insulating base 101 in a storage jig in which a plurality of recesses slightly larger than the outer dimensions of the insulating base 101 are formed, the apparent inner surface of the storage jig and the groove 106 After the sealing material 109 is positioned in the enclosed recessed area, the sealing material 109 may be irradiated with a laser beam. By doing so, the sealing material 109 can be easily positioned even if the groove 106 is open on the outer peripheral side surface side of the base 102. For the storage jig, for example, a heat-resistant material that can withstand the melting point of the carbon-based sealing material 109 and hardly react with the sealing material 109 may be used.

The melted sealing material 109 has a property that the insulating base 101 repels the sealing material 109 due to its surface tension, so that the first metallized layer 107 in the groove portion 106 opened to the side surface of the base portion 102.
In addition, even if the second metallized layer 108 is joined, it is possible to suppress the flow out to other regions (such as the mounting portion 104 and the outer peripheral side surface of the base portion 102).

Note that the opening formed by the groove 106 and the frame 103 needs to have a size that prevents the ball-shaped sealing material 109 from dropping from the opening. In order to achieve such a configuration, for example, the distance from the back side of the groove 106 to the inner surface of the base 102 may be made smaller than the diameter of the sealing material 109. Further, if the distance from the back side of the groove portion 106 to the inner surface of the base portion 102 is larger than the radius of the sealing material 109 and smaller than the diameter, the sealing material 109 can be positioned in the groove portion 106. Since part of the sealing material 109 enters and is fixed to the opening, it is not necessary to position the sealing material 109 by tilting the insulating base 101.

According to the piezoelectric device of the present invention, the piezoelectric vibration element housing package described above, the piezoelectric vibration element 105 mounted on the upper surface of the base portion 102, the lid body 113 bonded on the frame portion 103, and the groove portion 106 are provided. And a sealing material 109 which is closed. The volume of the sealing material 109 that closes the groove 106 can be easily secured. Therefore, for example, a piezoelectric device with high reliability of hermetic sealing can be provided even if the device is downsized. That is, even if the piezoelectric vibration element housing package is downsized by the gas discharge groove portion 106, the opening portion of the groove portion 106 can be formed to communicate from the lower surface of the base portion 102 to the outer peripheral side surface, and the opening for inserting the sealing material 109 can be formed. The part can be made larger than before. Therefore, the volume of the sealing material 109 can be secured even in a miniaturized wiring board.

Then, in the sealing step when sealing with the sealing material 109, the first metallized layer 107 and the second metallized layer in the groove portion 106 in which the sealing material 109 melted by heating means such as a laser beam is opened on the side surface of the base 102 is provided. Joined to 108, the groove 106 is closed. Therefore, a sufficient volume of the sealing material 109 for closing the opening of the groove 106 can be ensured, and a piezoelectric device having stable frequency characteristics with excellent sealing reliability over a long period of time can be provided.

In the above description, as shown in FIGS. 1 and 2, the groove 106 is provided in the central portion on the long side of the insulating base 101, but it depends on the shape of the insulating base 101 and the arrangement of the wiring conductors 110 in the mounting portion 104. For example, the groove 106 may be provided in the central portion on the short side opposite to the wiring conductor 110 to which the piezoelectric vibration element 105 is bonded. In this case, since the free end of the piezoelectric vibration element 105 is positioned near the upper side of the opening formed by the groove 106, an excitation electrode (on the piezoelectric vibration element 105 formed by irradiating an ion beam or the like from this opening ( It is possible to perform frequency adjustment by trimming (not shown).

1 and 2, the groove 106 is formed in the base 102 made of a single insulating layer. However, the groove 106 is formed as a base 102 made of a plurality of insulating layers according to the convenience of the wiring path of the insulating base 101. May be. In this case, the opening portion of the groove portion 106 needs to be closed with the sealing material 109, and at least the frame portion 103 and the inner side surface of the groove portion 106 in contact with the opening portion among the inner side surfaces of each groove portion 106 are the first. A metallized layer 107 is formed.

Further, when the groove 106 is composed of a plurality of insulating layers, the diameter of the groove 106 may be larger on the lower surface side (lower side) of the base portion 102 than on the frame 103 side (upper side). As a result, the sealing material 109 can be easily inserted into the groove 106, and the positioning of the sealing material 109 in the groove 106 can be stabilized.

  Next, the multi-piece wiring board of the present invention will be described with reference to the accompanying drawings. FIG. 3A is a top view showing a multi-piece wiring board according to the embodiment of the present invention, and FIG. 3B is a cross-sectional view taken along line B-B ′ of FIG. In FIG. 3, the same reference numerals are assigned to the same parts as in FIG. In FIG. 3, 201 is a mother board, 202 is a lower insulating layer, 203 is an upper insulating layer, 204 is a wiring board area, 205 is a margin area, 206 is a boundary, 207 is a plating conduction terminal, 208 is a frame conductor for plating, Reference numeral 209 denotes a through hole that becomes the groove 106 after the division. In FIG. 3, a specific pattern of the wiring conductor 110 is omitted for easy viewing.

  The multi-piece wiring board is divided along the boundary 206 of the wiring board region 204, and for example, a single piezoelectric vibration element housing package as shown in FIG. 1 is manufactured.

An electronic component (not shown) housed in the individual piezoelectric vibration element housing package is the piezoelectric vibration element 105 such as a crystal vibration element as described above. In addition, various electronic components such as a semiconductor element such as a semiconductor integrated circuit element (IC), a capacitive element, an inductor element, and a resistance element may be housed together with the piezoelectric vibration element 105 to form a piezoelectric device. The piezoelectric vibration element 105 operates in an airtight sealed environment. Therefore, the upper surface of each wiring board region 204 divided into individual pieces has a structure covered with a lid 113 made of metal or the like.

The mother substrate 201 includes a flat lower insulating layer 202 and a flat upper insulating layer 203 in which a plurality of openings (for example, rectangular through holes) (not shown) are arranged. In the lower insulating layer 202, a plurality of regions serving as the bottom surface of the mounting portion 104 of the piezoelectric vibration element 105 are arranged.
The upper insulating layer 203 is laminated on the upper surface of the lower insulating layer 202 so that the opening of the upper insulating layer 203 surrounds the region that becomes the bottom surface of the mounting portion 104. A region serving as a bottom surface of the mounting portion 104 in the lower insulating layer 202 is surrounded by the opening of the upper insulating layer 203, so that the mounting portion 104 of the piezoelectric vibration element 105 is formed. Each region having the mounting portion 104 is a wiring substrate region 204 that serves as an individual piezoelectric vibration element storage package. That is, on the mother board 201, a plurality of rectangular wiring board regions 204 having the mounting portion 104 of the piezoelectric vibration element 105 in the center of the upper surface are arranged vertically and horizontally.

  In the example shown in FIG. 3, a margin area 205 is provided on the outer periphery of the mother board 201 so as to surround a plurality of wiring board areas 204 arranged. The disposal allowance area 205 is provided to facilitate handling of the multi-piece wiring board.

The lower insulating layer 202 and the upper insulating layer 203 constituting the mother substrate 201 are each made of, for example, a flat ceramic sintered body as described above. Examples of the ceramic sintered body include an aluminum oxide sintered body, a glass ceramic sintered body, an aluminum nitride sintered body, a silicon carbide sintered body, a silicon nitride sintered body, and a mullite sintered body. Can be mentioned.

  The lower insulating layer 202 and the upper insulating layer 203 may each be formed by laminating a plurality of insulating layers (not shown).

The mother substrate 201 composed of the lower insulating layer 202 and the upper insulating layer 203 is produced, for example, by laminating a plurality of insulating layers as described above and firing them integrally. That is, a suitable organic solvent and binder are added to raw powders such as aluminum oxide and silicon oxide and formed into a sheet shape to produce a plurality of ceramic green sheets. It shall have an opening. Then, the ceramic green sheet which has an opening part is laminated | stacked on the flat ceramic green sheet which has not performed punching, and this ceramic green sheet laminated body is integrally baked. Thus, the mother substrate 201 made of an aluminum oxide sintered body or the like is manufactured.

Each of the plurality of wiring board regions 204 arranged on the mother board 201 is provided with a wiring conductor 110 as in the case of the piezoelectric vibration element storage package. The wiring conductor 110 is connected to the outer surface of the individual piece, for example, the lower surface of the wiring board region 204 (insulating base 101) via a connecting conductor (not shown), as in the piezoelectric vibration element storage package. It is derived electrically. The connection conductor may include a through conductor (a so-called via conductor or the like, not shown) formed in the mother board 201, an internal wiring layer, or the like. Further, an electrode (not shown) for external connection may be provided on the lower surface of the mother board 201 (wiring board area 204), similarly to the piezoelectric vibration element storage package.

The wiring conductor 110 is formed of a metal material such as tungsten, molybdenum, manganese, copper, silver, palladium, gold, or platinum. If each wiring conductor 110 is made of tungsten, for example, a metal paste prepared by kneading tungsten powder together with an organic solvent and a binder is applied to a predetermined portion of the ceramic green sheet to be the mother substrate 201 by a screen printing method or the like. It is possible to form the film by depositing it by the above method and co-firing.

The wiring conductor 110 may be coated with a plating layer (not shown) such as nickel as described above. The plating layer is deposited, for example, in an electroplating solution such as nickel via the plating conduction terminal 207 plating frame conductor 208 provided on the mother board 201, the castellation 112, the frame-like metallization layer 111, etc. This can be done by supplying a plating current to the wiring conductor 110 of each wiring board region 204.

The plating conduction terminal 207 and the plating frame conductor 208 can also be formed by the same method using the same metal material as the wiring conductor 110.

The frame-like metallized layer 111 in the multi-piece wiring board also has the same function as the frame-like metallized layer 111 in the individual piezoelectric vibration element housing package. The frame-like metallized layer 111 is also made of the same metal material as described above, and is provided by the same method. Moreover, a plating layer (not shown) may be applied in the same manner as described above. A detailed description of the frame-like metallized layer 111 in the multi-cavity wiring board is omitted.

The produced piezoelectric vibration element housing package has, for example, a rectangular flat plate-like insulating base 101 having a concave mounting portion 104, and the mounting portion, similarly to the piezoelectric vibration element housing package of the above embodiment. A plurality of connection conductors are led out from the wiring conductor 110 provided in 104 to the lower surface of the insulating base 101.

A through-hole 209 is formed in the lower insulating layer 202 so as to straddle one boundary 206 of the wiring substrate region 204 in the mother substrate 201 in which the plurality of wiring substrate regions 204 on which the piezoelectric vibration element 105 is mounted are arranged vertically and horizontally. The upper end portion of the through hole 209 is connected to the opening, the first metallized layer 107 is formed on the inner surface of the through hole 209, and the lower surface of the upper insulating layer 203 exposed to the through hole 209 is Two metallized layers 108 are formed.

A through-hole 209 is formed in the lower insulating layer 202 in the mother board 201 so as to straddle one boundary 206 of the wiring board region 204. A part of the upper end portion of the through hole 209 is located inside the inner periphery of the opening. That is, the upper end of the opening is connected to the opening of the upper insulating layer 203. When the mother board 201 is divided along the boundary 206, the through hole 209 is divided along the boundary 206 in the vertical direction. The divided through hole 209 becomes a groove 106 on the side surface of the insulating base 101 of the individual piezoelectric vibration element housing package.

  A first metallized layer 107 is formed on the inner surface of the through hole 209, and a second metallized layer 108 is formed on the lower surface of the upper insulating layer 203 exposed in the through hole 209.

By dividing such a multi-piece wiring board including the mother board 201 along the boundary 206, the piezoelectric vibration element housing package (insulating base 101) having the above-described configuration can be easily obtained. That is, the wiring board region 204 is a single piezoelectric vibration element housing package, the through hole 209 is a groove portion 106 of the piezoelectric vibration element housing package, and the first and second metallized layers 107 and 108 are formed in the groove portion 106. Is provided.

Dividing the mother substrate 201 along the boundary 206 is performed by, for example, a dicing process or a method of breaking the mother substrate 201 in a dividing groove (not shown) provided in advance along the boundary 206.

In order to form the first metallized layer 107, for example, the same metal material paste as in the case of the wiring conductor 110 or the like is applied in the through hole 209 to be the groove portion 106 together with vacuum suction. Just keep it. Furthermore, in order to form the second metallized layer 108, for example, a paste of the above metal material is applied to a portion exposed on the through hole 209 side of the lower surface of the ceramic green sheet laminate that becomes the frame portion 103 by a screen printing method or the like. It may be formed by the method. At this time, the lower surface of the upper insulating layer 203 is slightly wider than the portion exposed to the through hole 209 side so that a region where the metallized layer is not formed is generated between the first metallized layer 107 and the second metallized layer 108. Therefore, it is necessary to form the second metallized layer 108. This is because, when a region where the metallized layer is not formed is generated between the first metallized layer 107 and the second metallized layer 108, the groove portion 106 is formed by the sealing material 109.
This is because there is a possibility that a portion that cannot be closed is formed and the mounting portion 104 cannot be hermetically sealed.

Even in the multi-cavity wiring board, a plating layer (not shown) such as nickel is deposited on the exposed surfaces of the first and second metallized layers 107 and 108, and the bonding property (wetting property, etc.) of the sealing material 109 is applied. ) May be enhanced. If a plating layer is applied to the wiring conductor 110, the frame-like metallized layer 111, the first metallized layer 107, and the second metallized layer 108 in the state of a multi-piece wiring substrate, the piezoelectric vibration element is obtained as a single piece. Productivity of the storage package is increased.

A through hole 209 is formed across the boundary 206 between the adjacent wiring board regions 204. That is, for example, compared to a case where a through hole, that is, an opening (not shown) is provided near the boundary 206 and separated from the boundary 206, problems such as cracking when the mother board 201 is divided are less likely to occur. . This is because there is no portion where the distance between the boundary 206 and the opening portion is small, which tends to be an inadvertent crack starting point during division. If a through-hole is provided near the boundary 206, the boundary 206 is caused by stress when the mother board 201 is divided along the boundary 206.
Unnecessary cracks are easily generated from the through hole to the through hole. On the other hand, if the through-hole 209 straddles the boundary 206 as in the multi-cavity wiring board of the embodiment, that is, the portion where the lower insulating layer 202 has already been divided into a part of the boundary 206. If the through hole 209 is located, the above stress does not occur. Therefore, the possibility of inadvertent cracking or the like in the lower insulating layer 202 or the like can be reduced.

  Note that the division groove is formed along the boundary 206 of the wiring board region 204, for example, in the mother board 201 in the multi-cavity wiring board of the embodiment.

The dividing groove is formed by, for example, cutting a cutter blade or the like at a predetermined depth along the boundary 206 of the wiring board region 204 into at least one of the upper surface and the lower surface of the multilayer body of ceramic green sheets to be the mother substrate 201. Can be formed. The mother board 201 is divided into individual insulating bases 101 by applying stress to the mother board 201 at the portion where the dividing groove is formed (border 206 of the wiring board region 204) and breaking the mother board 201 in the thickness direction. Is done.

Of the dividing grooves, those formed on the upper surface of the mother substrate 201 may be formed deeper than the thickness of the frame portion 103. In this case, the mother board 201 can be more easily divided into individual pieces. Further, the dividing groove may be formed shallower than the thickness of the frame portion 103. In this case, if the mother substrate 201 is divided by applying stress so that the dividing groove on the upper surface is opened, not dividing the lower substrate so as to open the dividing groove on the lower surface, the substrate can be divided satisfactorily.

In the multi-cavity wiring board of the embodiment, the through hole 209 is located at the center in the length direction of one side of the rectangular (rectangular) wiring board region 204. In other words, the through hole 204 is located at the center in the length direction of one boundary 206 of the wiring board region 204. Adjacent wiring board regions 204 are arranged point-symmetrically with respect to the through holes 209. Therefore, the wiring substrate regions 204 can be efficiently arranged on the mother substrate 201 without forming dummy regions between the wiring substrate regions 204, and the piezoelectric substrate having the above-described configuration can be formed by dividing along the boundary 206. The vibration element storage package (insulating base 101) can be easily obtained.

The shape of the through hole 209 in the multi-cavity wiring board of the embodiment is elliptical in plan view (bottom view). The through hole 209 is in the shape of a long hole (rectangular shape or rectangular shape with corners arced, etc.)
It may be.

The groove portion 106 of the individual piezoelectric vibration element storage package provided by the through hole 209 has an elliptical arc shape, a rectangular shape, or the like. The groove 106 needs to be formed so that the sealing material 109 does not come out from the upper end portion (opening portion on the upper end side) located inside the inner periphery of the frame portion 103. If the through hole 209 has an elliptical shape, the curvature of the outer peripheral portion most distant from the frame portion 103 of the through hole 209 may be made smaller than the radius of the sealing material 109. As a result, a structure in which the sealing material 109 inserted into the groove 106 cannot be removed from the through hole 209 toward the mounting portion 104 can be obtained.

According to such a multi-cavity wiring board, it is only necessary to process the through holes 209 that are ½ of the number of wiring board regions 204, so that the structure of a mold or the like for processing the ceramic green sheet can be simplified. it can.

For example, if the wiring board regions 204 arranged and formed on the mother board 201 are 16 pieces of 4 rows × 4 columns, and if a through hole (not shown) is provided for each wiring board region 204, It is necessary to process 16 through holes. On the other hand, if the through hole 209 is provided across the boundary 206 as described above, the through hole 209 may be processed at one place on the long side of the two wiring board regions 204 adjacent to each other. It will be.

Further, the piezoelectric vibrating element 105 is mounted on the mounting portion 104 of each wiring board region 204 in the state of a multi-piece wiring board.
After the lid body 113 is joined to the upper surfaces of all the wiring board regions 204, the mother board 201 is turned upside down to constitute the gas discharge opening (the through hole 209 and the inner periphery of the frame part 103). It is also possible to close the through hole 209 with a sealing material 109 such as a brazing material after the gas is discharged to the outside from the opening portion). In this case, it is possible to perform hermetic sealing on the mounting portions 104 of all the wiring board regions 204 in a lump. In this case, since the opening portions of the through holes 209 of the two adjacent wiring board regions 204 can be simultaneously closed by one sealing material 109, the sealing process can be further simplified. In this case, in order to make the mother substrate 201 into individual pieces, the sealing material 109 formed at the boundary 206 is formed, and the splitting property of the mother substrate 201 may be deteriorated. The method using dividing grooves is not suitable. If slicing is performed, the through hole 209
The sealing material 109 located at the boundary 206 can also be cut at the same time, and can be easily separated.

As shown in FIG. 3, for example, when the through-hole 209 is provided in the central part on the long side of the rectangular wiring board region 204, the following points are advantageous. That is, the piezoelectric vibration element 105 is generally a rectangular parallelepiped, and accordingly, the insulating base 101 (wiring board region 204) is also manufactured in a rectangular parallelepiped. If the through hole 209 is provided in the central part on the long side, the interval between the adjacent through holes 209 can be increased. Therefore, when the ceramic green sheet to be the mother substrate 201 (lower insulating layer 202) is punched with a mold or the like, it is possible to suppress a local decrease in the rigidity of the punched ceramic green sheet. Therefore, it is possible to perform stacking in which stacking deviation between the upper and lower ceramic green sheets is suppressed.

Further, as shown in FIG. 4, for example, a through hole 209 may be provided in the central portion on the short side of the wiring board region 204. 4A is a plan view showing a modification of the multi-piece wiring board according to the embodiment of the present invention, and FIG. 4B is a cross-sectional view taken along the line CC ′ of FIG. 4A. It is. 4, parts similar to those in FIGS. 1 and 3 are given the same reference numerals.

In this case, as described above, the free end of the piezoelectric vibration element 105 can be positioned near the opening on the upper end side (the mounting portion 104 side) of one through-hole 209. Therefore, the frequency adjustment can be performed by trimming the excitation electrode (not shown) of the piezoelectric vibration element 105 by irradiating an ion beam or the like from the opening. In this case, a plurality of piezoelectric devices with high accuracy and excellent frequency characteristics can be manufactured at once. In order to obtain this effect, in the rectangular mounting portion 104 in plan view, the wiring conductor 110 to which the piezoelectric vibration element 105 is connected is positioned on one short side of the mounting portion 104 and the through hole 209 (upper end) Side opening) must be located on the other short side.

  The piezoelectric vibration element storage package, the piezoelectric device, and the multi-cavity wiring board of the present invention are not limited to the above embodiments, and various modifications can be made without departing from the gist of the present invention. You can add anything. For example, in the example of the above-described embodiment, an example in which only the piezoelectric vibration element 105 is mounted on the mounting portion has been described. However, together with the piezoelectric vibration element 105, a semiconductor element such as a semiconductor integrated circuit element (IC), a capacitive element, an inductor element, a resistance It may be a piezoelectric vibration element storage package, a piezoelectric device, and a multi-piece wiring board used for TCXO, VCO, etc., on which various electronic components such as elements are mounted.

101 ... Insulating substrate
102 ... Base
103 ・ ・ ・ Frame part
104 ・ ・ ・ Mounting part
105 ・ ・ ・ Piezoelectric vibration element
106 ・ ・ ・ Groove
107 ... 1st metallization layer
108 ... 2nd metallization layer
109 ・ ・ ・ Sealing material
110 ・ ・ ・ Wiring conductor
111 ・ ・ ・ Frame metallization layer
112 ・ ・ ・ Castellation
113 ・ ・ ・ Cover
201 ... Mother board
202 ... lower insulation layer
203 ... Upper insulating layer
204 ・ ・ ・ Wiring board area
205 ・ ・ ・ Disposal allowance area
206 ... Boundary
207 ... Plating conduction terminal
208 ・ ・ ・ Frame conductor for plating
209 ... Through hole

Claims (4)

A flat base having an upper surface including a portion on which the piezoelectric vibration element is mounted;
A piezoelectric vibration element storage package comprising: a frame portion that surrounds a portion on which the piezoelectric vibration element is mounted on the upper surface of the base portion;
On the side surface of the base portion, a groove portion is provided from the upper end to the lower end of the side surface, and a part of the upper end of the groove portion is located on the inner side of the inner periphery of the frame portion,
A first metallized layer is provided on the inner side surface of the groove part, and a second metallized layer is provided on the lower surface of the frame part exposed inside the groove part,
A package for accommodating a piezoelectric vibration element, wherein a sealing material is bonded to the first metallized layer and the second metallized layer to close the groove. The piezoelectric vibration element storage package according to claim 1;
A piezoelectric vibration element mounted on the upper surface of the base;
A lid joined on the frame;
A piezoelectric device comprising: a sealing material bonded to the first metallized layer and the second metallized layer to close the groove. A multi-piece wiring in which a plurality of wiring board regions are arranged on a mother board comprising a flat lower insulating layer and a plurality of openings and an upper insulating layer laminated on the upper surface of the lower insulating layer A substrate,
Each boundary of the plurality of wiring board regions surrounds the opening,
A through hole is formed in the lower insulating layer so as to straddle the boundary of the wiring board region, and a part of the upper end of the through hole is located inside the inner periphery of the opening,
The multi-piece wiring board, wherein a first metallized layer is formed on an inner surface of the through hole, and a second metallized layer is formed on a lower surface of the upper insulating layer exposed in the through hole. . In the plan view, the wiring board region has a quadrangular shape,
The through hole is located at a central portion in the length direction of one side of the wiring board region,
4. The multi-piece wiring board according to claim 3, wherein the wiring board regions adjacent to each other are arranged point-symmetrically with respect to the through hole.

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