JP6465484B2 - Package parts, electronic parts, and methods of manufacturing electronic parts - Google Patents

Description

  The present invention relates to a package component, an electronic component, and an electronic component manufacturing method.

  Conventionally, there is an electronic component in which an element such as an IC (Integrated Circuit) is accommodated in a package. As a package, there is a hollow package having a cavity structure. For example, Patent Document 1 discloses an electronic component package having a cavity for housing an electronic component, which has a mounting surface and surrounds a circuit board on which the electronic component is mounted and a mounting area on which the electronic component is mounted. An annular bonding pattern formed on the mounting surface, a lid having a shape such that a cavity is formed between the circuit board, and a solder layer for bonding the bonding pattern and the bonding surface of the lid. An electronic component package is disclosed.

  By the way, the element accommodated in the package is generally weak against moisture, and its characteristics may be deteriorated when exposed to a high humidity environment. For this reason, in a normal package, moisture is prevented from entering the cavity by hermetically sealing the cavity. The hermetic sealing of the cavity is realized by overlapping and bonding a pair of substrates with a bonding material such as a high melting point solder provided in an annular shape between the pair of substrates.

Japanese Patent No. 5372175

  However, when the cavity is hermetically sealed, the internal pressure of the cavity may increase due to volatilization of components contained in the bonding material. Thereby, the differential pressure inside and outside the package acts on the bonding material for bonding the pair of substrates. In particular, when the bonding material is a high melting point solder, in order to heat the pair of substrates to melt the bonding material, in addition to volatilization of the components contained in the bonding material, expansion of gas in the cavity also occurs, The differential pressure inside and outside the package increases. At this time, if the bonding material has fluidity, a gap (hereinafter referred to as “leak path”) is formed in the bonding material so as to communicate the inside and outside of the package, and the cavity may not be hermetically sealed. In addition, the leak path formed in the bonding material is often very small, and the position where the leak path is formed is not regular, so it is difficult to confirm the bonding state of the pair of substrates. Therefore, the conventional package has a problem in that the inside of the package is surely hermetically sealed while confirming the bonding state.

  Therefore, the present invention provides a package component, an electronic component, and a method for manufacturing the electronic component that can reliably and hermetically seal the inside of the package and can easily check the bonding state.

The packaging component according to the present invention includes a base substrate that is overlapped and bonded, a lid substrate that covers an element mounted on the base substrate, and a corner portion of the base substrate in the entire thickness direction of the base substrate. And a bonding material that is arranged along the outer edge of the base substrate as seen from the overlapping direction of the base substrate and the lid substrate and is divided at a position corresponding to the notch portion. It is characterized by providing.
Here, in the process of bonding the base substrate and the lid substrate, a superposed state of the base substrate and the lid substrate referred to as "bonding Initial state". Further, a state in which the bonding material interposed between the superimposed base substrate and the lid substrate spreads out is referred to as a “late bonding state”.
According to the present invention, since the bonding material is divided at a position corresponding to the notch, the package component is formed between the notch of the base substrate and the lid substrate in the initial bonding state when the package is formed. There is a gap where no bonding material exists. For this reason, by letting gas flow through the gap between the notch and the lid substrate in the initial bonding state, the pressure difference between the inside and outside of the package that occurs when the base substrate and the lid substrate are bonded is eliminated, and a leak path is formed in the bonding material. It can be prevented from being formed. Further, in the late bonding state, the bonding material is wet and spread, whereby the gap between the notch and the lid substrate can be closed, and the inside of the package can be hermetically sealed. In addition, since the notch is formed at the corner of the base substrate, the operator can easily visually recognize the presence or absence of a gap between the notch of the base substrate and the lid substrate. Thereby, the operator can easily check whether or not the gap between the notch and the lid substrate is closed. Therefore, a package component can be obtained in which the inside of the package can be reliably hermetically sealed and the joined state can be easily confirmed.

In the above-described package component, it is preferable that the bonding material is a high melting point solder, and a metal film is formed in the notch.
According to the present invention, since the bonding material is a high melting point solder and a metal film is formed in the notch, the gap between the notch and the lid substrate is blocked by the wettability of the high melting point solder to the metal film. Meanwhile, the bonding material can be wetted and spread on the metal film in the notch. For this reason, the operator can easily confirm whether or not the gap between the notch and the lid substrate is closed by observing the bonding material that spreads wet on the notch. Therefore, it is possible to easily confirm the joining state.

The electronic component of the present invention includes the above-described package component and an element accommodated in the package component.
According to the present invention, by providing the package component described above, an electronic component can be obtained in which the inside of the package can be reliably hermetically sealed and the joined state can be easily confirmed.

Method for manufacturing an electronic component of the present invention is a manufacturing method of the electronic component, a mounting step of mounting the element to said base plate, and a bonding step of bonding the lid substrate and the base substrate, And the joining step includes an overlaying step of overlaying the base substrate and the lid substrate with the joining material interposed therebetween, and sealing for closing a gap between the notch portion and the lid substrate by the joining material. And a bonding state confirmation step of confirming the bonding material closing the gap between the notch and the lid substrate.
According to the present invention, since the joining process includes an overlapping process and a sealing process, the differential pressure inside and outside the package can be reduced by flowing a gas through the gap between the notch and the lid substrate before performing the sealing process. Can be resolved. Thereby, it can suppress that a leak path | pass is formed when performing a sealing process. Further, it is possible to confirm whether or not the gap between the notch formed in the corner of the base substrate and the lid substrate is closed by the bonding material in the bonding state confirmation step. Therefore, the gap between the notch portion and the lid substrate can be closed so that the inside of the package can be reliably hermetically sealed, and the joined state can be easily confirmed.

According to the present invention, since the bonding material is divided at a position corresponding to the notch, the package component is formed between the notch of the base substrate and the lid substrate in the initial bonding state when the package is formed. There is a gap where no bonding material exists. For this reason, by letting gas flow through the gap between the notch and the lid substrate in the initial bonding state, the pressure difference between the inside and outside of the package that occurs when the base substrate and the lid substrate are bonded is eliminated, and a leak path is formed in the bonding material. It can be prevented from being formed. Further, in the late bonding state, the bonding material is wet and spread, whereby the gap between the notch and the lid substrate can be closed, and the inside of the package can be hermetically sealed. In addition, since the notch is formed at the corner of the base substrate, the operator can easily visually recognize the presence or absence of a gap between the notch of the base substrate and the lid substrate. Thereby, the operator can easily check whether or not the gap between the notch and the lid substrate is closed. Therefore, a package component can be obtained in which the inside of the package can be reliably hermetically sealed and the joined state can be easily confirmed.

It is an external appearance perspective view of an electronic component. It is a disassembled perspective view of an electronic component. It is sectional drawing in the III-III line of FIG. It is a flowchart which shows the manufacturing method of an electronic component. It is the perspective view which looked at the electronic component from the lower side.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Electronic parts)
FIG. 1 is an external perspective view of an electronic component. FIG. 2 is an exploded perspective view of the electronic component. 3 is a cross-sectional view taken along line III-III in FIG.
As shown in FIGS. 1 to 3, the electronic component 1 includes a package component 2 that forms a cavity C hermetically sealed therein, and an element 3 accommodated in the package component 2.

(Packaging parts)
The package component 2 includes a base substrate 11 (corresponding to “first substrate” in the claims) and a lid substrate 12 (corresponding to “second substrate” in the claims) and the base substrate 11 to be bonded together. And a bonding material 14. The package component 2 becomes the package 10 by overlapping and bonding the base substrate 11 and the lid substrate 12 with the bonding material 14 interposed therebetween. FIG. 2 shows a state before the base substrate 11 and the lid substrate 12 (hereinafter sometimes referred to as “each substrate 11, 12”) are bonded, and before the bonding material 14 is heated and melted, which will be described later. It is in the state of.
In the following description, the base substrate 11 side in the thickness direction of the package 10 is referred to as the lower side, and the lid substrate 12 side is referred to as the upper side.

  As shown in FIG. 2, the base substrate 11 is a rectangular plate formed of, for example, a high-temperature fired ceramic containing alumina. Note that the base substrate 11 may be, for example, a low-temperature fired ceramic substrate containing glass ceramics, a high heat-resistant glass epoxy substrate, or the like.

  A plurality of internal electrodes 15 are formed on the upper surface of the base substrate 11. A plurality of external electrodes 16 (see FIG. 3) are formed on the lower surface of the base substrate 11. The internal electrode 15 and the external electrode 16 are connected by a through electrode (not shown) that penetrates the base substrate 11 in the thickness direction. The internal electrode 15, the external electrode 16, and the through electrode (hereinafter also referred to as “each electrode”) have an electrode base film and an electrode base film formed on the electrode base film. The electrode base film is a metal film such as tungsten or molybdenum, and is formed by printing or baking, for example. The electrode base film is formed of, for example, a laminated film in which nickel and gold are laminated in this order by plating, a laminated film in which titanium, platinum, and gold are laminated in this order by sputtering or vapor deposition.

The notch 13 is formed at one corner of the four corners of the base substrate 11. The notch 13 has a ¼ arc shape in a plan view and is formed uniformly over the entire thickness of the base substrate 11. The notch 13 is formed by dividing a through hole serving as a reference for a cutting position when the base substrate 11 is formed by cutting a wafer-like ceramic substrate into a lattice shape.
A base metal film 17 (corresponding to “metal film” in the claims) is formed on the entire surface of the notch 13. The base metal film 17 is formed in the same manner as the above-described electrodes, and for example, the outermost surface is formed of gold.

  A bonding base film 18 is formed on the upper surface of the base substrate 11. The bonding base film 18 is formed in the same manner as the base metal film 17. The bonding base film 18 is formed on the upper surface of the base substrate 11 in a rectangular frame shape that is arranged with a predetermined width along the outer edge of the base substrate 11 in a plan view and is divided and opened at the notch 13. The width of the bonding base film 18 is smaller than the radius of curvature of the notch 13 in plan view. The bonding base film 18 is formed continuously with the base metal film 17.

  The bonding material 14 is formed on the bonding base film 18. That is, the bonding material 14 is arranged along the outer edge of the base substrate 11 in a plan view and is divided at a position corresponding to the notch 13. Thus, a portion where the bonding material 14 is not disposed is formed on the ridge line connecting the upper surface of the base substrate 11 and the notch 13. The bonding material 14 is preferably, for example, a lead-based, gold-based, or zinc-based high melting point solder. The bonding material 14 is disposed on the bonding base film 18 by printing and then melted by reflow, so that the bonding material 14 is in close contact with the bonding base film 18. Note that a flux may be applied to the surface of the bonding material 14 in order to improve the wettability of the bonding material 14 to the lid substrate 12 when the base substrate 11 and the lid substrate 12 described later are bonded.

  As shown in FIG. 3, the lid substrate 12 is a plate member having a rectangular shape in plan view that is formed to be recessed so that the lower surface is recessed upward. The lid substrate 12 is preferably formed of a material having a linear expansion coefficient close to that of the material forming the base substrate 11, and for example, a metal material such as Kovar, 42 alloy, and Permalloy B is preferable. The lid substrate 12 is formed by, for example, pressing or etching. The outer shape of the lid substrate 12 substantially matches the outer shape of the base substrate 11 in plan view. The lid substrate 12 includes a flange portion 12a having a rectangular frame shape in plan view formed along the outer periphery, and a concave portion 12b that is surrounded by the flange portion 12a and is recessed upward.

  The flange portion 12a of the lid substrate 12 is formed so as to overlap the bonding material 14 disposed on the base substrate 11 and the entire cutout portion 13 in a plan view in a state where the lid substrate 12 is superimposed on the base substrate 11. ing. The width of the flange portion 12a is larger than the widths of the bonding base film 18 and the bonding material 14, and smaller than the radius of curvature of the cutout portion 13 (see FIG. 1) in plan view. The recess 12 b of the lid substrate 12 forms a cavity C together with the upper surface of the base substrate 11 by overlapping the base substrate 11 and the lid substrate 12. Note that a metal film such as gold, silver, or palladium may be formed on the lower surface of the lid substrate 12 in order to improve the bondability between the lid substrate 12 and the bonding material 14.

(element)
The element 3 is accommodated in the cavity C in a state where the substrates 11 and 12 are bonded. The element 3 is, for example, a CMOS-IC, and more specifically, for example, a voltage regulator. As shown in FIG. 2, the element 3 is die-bonded and mounted at the center of the upper surface of the base substrate 11 with the circuit surface 31 on which the electronic circuit and the electrode pad 32 are formed facing upward. The adhesive for die bonding may be an insulating material or a conductive material. For example, a resin or the like can be used. Furthermore, the electrode pad 32 of the element 3 is connected to the internal electrode 15 on the base substrate 11 by wire bonding. As the wire for wire bonding, for example, gold, gold alloy, silver, silver alloy, or the like is used.

(Method for manufacturing electronic parts)
Next, a method for manufacturing the electronic component 1 will be described. In addition, refer to FIGS. 1 to 3 for the reference numerals of the respective components of the electronic component 1 in the following description.
FIG. 4 is a flowchart showing a method for manufacturing an electronic component.
As shown in FIG. 4, the manufacturing method of the electronic component 1 of the present embodiment includes a mounting step S10 for mounting the element 3 on the base substrate 11, a bonding step S20 for bonding the base substrate 11 and the lid substrate 12, A bonding state confirmation step S30 for confirming the bonding material 14 that closes the gap between the portion 13 and the lid substrate 12.

First, the mounting process S10 is performed.
In the mounting step S10, each electrode, the base metal film 17, the bonding base film 18, and the like are formed in advance, and the element 3 is die-bonded to the base substrate 11 on which the bonding material 14 is disposed. At this time, the element 3 is arranged so that the circuit surface 31 faces the side opposite to the upper surface of the base substrate 11 (upper side). Next, the electrode pad 32 of the element 3 and the internal electrode 15 of the base substrate 11 are connected by wire bonding. Thereby, the mounting of the element 3 on the base substrate 11 is completed.

Next, joining process S20 is performed.
The joining step S20 includes a superposition step S21 in which the base substrate 11 and the lid substrate 12 are superposed with the joining material 14 interposed therebetween, a heating step S23 in which the joining material 14 is heated and melted, and the notch 13 and the lid by the joining material 14. Sealing step S25 for closing the gap with the substrate 12.

  In the joining step S20, an overlaying step S21 is first performed. In the overlaying step S21, the lid substrate 12 is overlaid so as to overlap the base substrate 11 in plan view. Accordingly, the flange portion 12 a of the lid substrate 12 overlaps the bonding material 14 on the base substrate 11, and the concave portion 12 b of the lid substrate 12 covers the element 3 on the base substrate 11. At this time, since the bonding material 14 is divided at a position corresponding to the notch 13 in plan view, the bonding material is interposed between the notch 13 of the base substrate 11 and the flange portion 12a of the lid substrate 12. A gap in which no 14 is interposed is formed.

  Then, heating process S23 is performed. In the heating step S23, the superposed substrates 11 and 12 are heated by putting them in a heating furnace or the like, and the bonding material 14 interposed between the base substrate 11 and the flange portion 12a of the lid substrate 12 is heated. As a result, the bonding material 14 is melted, and the base substrate 11 and the lid substrate 12 are bonded.

FIG. 5 is a perspective view of the electronic component as viewed from below.
Subsequently, a sealing step S25 is performed. In the sealing step S25, the bonding material 14 is continuously heated following the heating step S23. Then, as shown in FIG. 5, the molten bonding material 14 oozes out between the base substrate 11 and the flange portion 12 a of the lid substrate 12. As a result, the bonding material 14 wets and spreads so as to block the space between the notch portion 13 of the base substrate 11 and the flange portion 12a of the lid substrate 12, and also spreads on the notch portion 13. At this time, since the base metal film 17 is formed on the surface of the notch 13, the molten bonding material 14 can easily spread on the notch 13. Next, heating of the bonding material 14 is stopped, and the molten bonding material 14 is solidified. As a result, the bonding material 14 is interposed between the base substrate 11 and the lid substrate 12 along the entire outer edge of each of the substrates 11 and 12, and each of the substrates 11 and 12 has hermetically sealed the cavity C. Are joined together.
The heating step S23 and the sealing step S25 may be performed in a heating furnace in a vacuum atmosphere or an inert gas atmosphere such as nitrogen.

Next, the joining state confirmation process S30 is performed.
In the bonding state confirmation step S30, the bonding material 14 that has spread wet so as to close the gap between the notch portion 13 of the base substrate 11 and the flange portion 12a of the lid substrate 12 in the sealing step S25 is visually confirmed.
Thus, the manufacture of the electronic component 1 in which the cavity C is hermetically sealed is completed.

As described above, the packaging component 2 according to the present embodiment includes the substrates 11 and 12 to be bonded together, the cutout portions 13 formed at the corners of the base substrate 11, and the substrates 11 and 12. And a bonding material 14 that is arranged along the outer edge of the base substrate 11 as viewed from the direction and is divided at a position corresponding to the notch 13.
Here, in the process of bonding the substrates 11 and 12, a state in which the base substrate 11 and the lid substrate 12 are overlapped is referred to as a “bonding initial state”. In addition, a state in which the bonding material 14 interposed between the overlapped base substrate 11 and lid substrate 12 spreads out is referred to as a “late bonding state”.
According to this configuration, since the bonding material 14 is divided at a position corresponding to the notch portion 13, when forming the package 10, the package component 2 is in the notched portion 13 of the base substrate 11 in the initial bonding state. And the lid substrate 12 have a gap where the bonding material 14 does not exist. For this reason, in the initial bonding state, by causing the gas to flow through the gap between the notch 13 and the lid substrate 12, the pressure difference between the inside and outside of the package 10 generated when the base substrate 11 and the lid substrate 12 are bonded is eliminated. It is possible to prevent a leak path from being formed in the bonding material 14. Further, in the late bonding state, the gap between the notch 13 and the lid substrate 12 can be closed by wetting and spreading the bonding material 14, and the cavity C can be hermetically sealed. In addition, since the notches 13 are formed at the corners of the base substrate 11, the operator can easily visually recognize the presence or absence of a gap between the notches 13 of the base substrate 11 and the flange portions 12 a of the lid substrate 12. As a result, the operator can easily check whether or not the gap between the notch 13 and the lid substrate 12 is closed. Therefore, the package component 2 can be obtained in which the cavity C can be surely hermetically sealed and the joined state can be easily confirmed.

  Further, the bonding material 14 is a high melting point solder, and a base metal film 17 is formed in the cutout portion 13. For this reason, as compared with the case where the surface of the notch 13 is formed of ceramic or resin, the gap between the notch 13 and the lid substrate 12 is blocked by the wettability of the high melting point solder to the base metal film 17. The bonding material 14 can be wetted and spread on the base metal film 17 of the notch 13. For this reason, the operator can easily confirm whether or not the gap between the notch 13 and the lid substrate 12 is closed by observing the bonding material 14 that spreads wet on the notch 13. Therefore, it is possible to easily confirm the joining state.

  In addition, the electronic component 1 of the present embodiment includes the package component 2 described above. For this reason, the electronic component 1 can be obtained in which the cavity C can be reliably hermetically sealed and the joined state can be easily confirmed.

  Further, in the method for manufacturing the electronic component 1 according to the present embodiment, the bonding step S20 includes the overlapping step S21 and the sealing step S25. The differential pressure inside and outside the package 10 can be eliminated by allowing the gas to flow through. Thereby, it can suppress that a leak path | pass is formed when performing sealing process S25. Further, it is possible to confirm whether or not the gap between the notch 13 formed at the corner of the base substrate 11 and the lid substrate 12 is closed by the bonding material 14 in the bonding state confirmation step S30. Therefore, the gap between the notch 13 and the lid substrate 12 can be closed to securely seal the cavity C, and the joined state can be easily confirmed.

The present invention is not limited to the above-described embodiment described with reference to the drawings, and various modifications can be considered within the technical scope thereof.
For example, in the above embodiment, the notch 13 is formed at one corner of the base substrate 11, but the present invention is not limited to this, and may be formed at a plurality of corners of the base substrate 11, for example.
In the above embodiment, the notch 13 is formed in the base substrate 11. However, the present invention is not limited to this, and the notch may be formed in the lid substrate 12.

In the above embodiment, the bonding material 14 is disposed on the base substrate 11. However, the present invention is not limited to this, and the bonding material may be disposed on the lower surface of the flange portion 12 a of the lid substrate 12.
Moreover, in the said embodiment, although the joining material 14 was a high melting point solder, it is not limited to this, A joining material may be a metal paste for low temperature baking, low melting glass, an adhesive agent, etc.

In the above embodiment, the element 3 is mounted on the base substrate 11 by die bonding and wire bonding. However, the present invention is not limited to this. For example, the element 3 is mounted on the base substrate 11 by flip chip bonding. May be.
Moreover, in the said embodiment, although the voltage regulator was mentioned as an example and demonstrated as the element 3, it is not limited to this, For example, the element 3 may be an element containing a sensor, a sensor, and a circuit for sensor control. .

  Moreover, in the said embodiment, although the notch part 13 was formed in the planar view 1/4 circular arc shape, it is not limited to this, The shape notched in the planar shape may be sufficient. Even in this case, the flange portion and the notch portion of the lid substrate are formed so that the flange portion of the lid substrate and the entire notch portion overlap each other in plan view with the lid substrate overlapped with the base substrate. Is desirable.

  Moreover, in the said embodiment, although the notch part 13 was uniformly formed over the whole thickness direction of the base substrate 11, it is not limited to this, The notch part 13 is the thickness direction of the base substrate 11 It may be formed in a tapered shape inclined with respect to. Thereby, when performing sealing process S25, the speed | rate which the molten joining material 14 spreads over the notch part can be adjusted.

  In addition, it is possible to appropriately replace the components in the above-described embodiments with known components without departing from the spirit of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Electronic component 2 ... Package component 3 ... Element 11 ... Base board | substrate (1st board | substrate) 12 ... Lid board | substrate (2nd board | substrate) 13 ... Notch part 14 ... Joining material S10 ... Mounting process S20 ... Joining process S21 ... Overlay Process S25 ... Sealing process S30 ... Joining state confirmation process

Claims (4)

A base substrate that is overlapped and bonded, and a lid substrate that covers an element mounted on the base substrate ;
A corner of the base substrate, and the notch portion formed throughout the thickness direction of the base substrate,
A bonding material that is arranged along the outer edge of the base substrate as seen from the overlapping direction of the base substrate and the lid substrate and is divided at a position corresponding to the notch,
A package component comprising: The bonding material is a high melting point solder,
A metal film is formed in the notch,
The package component according to claim 1, wherein: The packaging component according to claim 1 or 2,
An element housed in the packaging component;
An electronic component comprising: It is a manufacturing method of the electronic component according to claim 3,
A mounting step of mounting the element to said base plate,
A bonding step of bonding the base substrate and the lid substrate;
With
The joining step includes
An overlaying step of overlaying the base substrate and the lid substrate with the bonding material interposed therebetween;
A sealing step of closing a gap between the notch and the lid substrate by the bonding material;
A bonding state confirmation step of confirming the bonding material that blocks the gap between the notch and the lid substrate;
Having
An electronic component manufacturing method characterized by the above.

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