JP7155659B2 - Hermetic package and method for manufacturing hermetic package - Google Patents

Description

The present invention relates to a hermetic package and a method for manufacturing a hermetic package.

Patent Document 1 discloses, as an example of an airtight package for housing a photoelectric element, a container portion (package base material) having an opening, a lid portion (cover member) joined to the container portion so as to close the opening, and a bonding material (bonding layer) that bonds the container portion and the lid portion. In this package, the bonding material is formed by hardening glass paste or the like applied to the container.

JP 2015-88579 A

In the package as described above, when the container portion and the lid portion are joined together, for example, a compressive load is applied to the glass paste while the glass paste is heated to a degree of softening. Therefore, if there are variations in the amount of glass paste applied and the compressive load applied to the glass paste, the softened glass paste may flow into the container. If such an inflow occurs, it may adversely affect the photoelectric element arranged in the container, or the airtightness of the package may be deteriorated.

An object of the present invention is to provide an airtight package and a method for manufacturing an airtight package that can prevent a bonding layer from protruding into a concave portion of a package base when bonding a cover member and the package base.

An airtight package that solves the above problems has a bottom wall and a peripheral wall extending from the bottom wall, a package base capable of accommodating a photoelectric element in a recess surrounded by the bottom wall and the peripheral wall, and a light-transmitting package base material. a cover member that closes the recess; and a bonding layer that joins the package base material and the cover member, wherein the cover member faces the light-transmitting portion facing the recess and the tip surface of the peripheral wall. and a bonding layer, and in the distal end surface of the peripheral wall, when the inner portion near the recess is defined as a first distal end surface and the outer portion far from the recessed portion is defined as a second distal end surface, the joint portion is the It includes a first joining portion that contacts the first tip surface, and a second joining portion that is joined to the second tip surface via the joining layer.

According to the above configuration, the first joint portion of the cover member contacts the first end face of the peripheral wall of the package base material. For this reason, the recess in which the photoelectric element is accommodated is less likely to be connected to the space in which the bonding layer is provided, that is, the space between the second bonding portion of the cover member and the second tip surface of the package base. Therefore, even if a compressive load acts on the bonding material forming the bonding layer in order to bond the cover member and the package base material, the bonding material does not easily flow into the recess. Therefore, the airtight package can prevent the bonding layer from protruding into the concave portion of the package base material.

In the cover member, when the surface facing the package base is defined as the inner surface, it is preferable that the inner surface of the translucent portion and the inner surface of the first joint portion are on the same plane.
In the hermetic package having the above configuration, the cover member can be easily manufactured. For example, it is possible to form the inner surface of the translucent portion and the inner surface of the first joint portion at once through a polishing process or the like.

In the cover member, when the surface facing the package base is defined as an inner surface and the surface opposite to the inner surface is defined as an outer surface, the outer surface of the translucent portion and the outer surface of the joint portion are on the same plane. is preferred.

In the hermetic package having the above configuration, the cover member can be easily manufactured. For example, it is possible to form the outer surface of the translucent portion and the outer surface of the joint portion at once through a polishing process or the like.
In the above airtight package, it is preferable that the translucent portion has a flat plate shape.

According to the above configuration, the light incident on the translucent portion passes through the translucent portion as it is. Therefore, in the airtight package, the translucent portion can function as a mere cover that covers the concave portion.

In the above airtight package, it is preferable that the translucent section has an optical element.
According to the above configuration, the hermetic package can provide the translucent portion with an optical function such as condensing, dispersing, diffracting, or refracting incident light.

In the airtight package, the cover member is preferably made of glass.
According to the above configuration, it becomes easy to form the shape of the cover member of the translucent portion and the joint portion by a manufacturing method such as mold pressing.

A method of manufacturing an airtight package that solves the above problems is any one of the methods of manufacturing an airtight package described above, wherein: an arrangement step of arranging the cover member on the peripheral wall of the package base material; and a joining step of joining the second joint portion of the member to the second end face of the peripheral wall of the package base via the joint layer.

According to the above configuration, in the method for manufacturing an airtight package, it is possible to obtain the same effects as those of the airtight package described above.

ADVANTAGE OF THE INVENTION According to this invention, when joining a cover member and a package base material, it can suppress that a joining layer protrudes into the recessed part of a package base material.

(a) is a plan view of an electronic device, and (b) is an end view taken along line 1b-1b. (a) to (c) are end views for explaining a method for manufacturing an electronic device. (a) is an end view of an electronic device according to a first modification, and (b) is an end view of an electronic device according to a second modification.

An embodiment of an airtight package (electronic device) will be described below with reference to the drawings.
As shown in FIGS. 1A and 1B, the electronic device 10 includes a photoelectric element 11 and an airtight package 12 that seals the photoelectric element 11 . The airtight package 12 includes a package base 20 that houses the photoelectric element 11, a cover member 30 that seals the photoelectric element 11 together with the package base 20, a bonding layer 40 that bonds the package base 20 and the cover member 30, Prepare. In this embodiment, the electronic device 10 has a box-like shape with a side of several millimeters to several centimeters.

The photoelectric element 11 may be a light-emitting element such as a light-emitting diode or a semiconductor laser, or a light-receiving element such as a photodiode, a phototransistor, or a phototube. The photoelectric element 11 handles, for example, light with a wavelength such as deep ultraviolet. One or more photoelectric elements 11 may be sealed in the airtight package 12, or a set of a light emitting element and a light receiving element may be sealed.

The package substrate 20 is made of, for example, ceramics such as aluminum oxide, aluminum nitride, zirconia or mullite, glass ceramics such as low temperature co-fired ceramics, or glass. Low-temperature co-fired ceramics are, for example, sintered bodies of inorganic powder such as titanium oxide or niobium oxide and glass powder.

The package base 20 has a bottom wall 21 having a rectangular shape in plan view and a peripheral wall 22 extending from the bottom wall 21 . The height of the peripheral wall 22 is constant in the direction in which the peripheral wall 22 extends with respect to the bottom wall 21 (extension direction). In other words, the distal end surface 23 of the peripheral wall 22 is planar. A recess 24 is formed in the package base 20 as a space surrounded by the bottom wall 21 and the peripheral wall 22 . The recess 24 is a space for accommodating the photoelectric element 11 .

In the description below, as shown in FIG. and The first tip surface 25 is a surface that connects to the inner surface of the peripheral wall 22 , and the second tip surface 26 is a surface that connects to the outer surface of the peripheral wall 22 . The first tip surface 25 and the second tip surface 26 are continuous surfaces that exist on the same plane.

The cover member 30 is made of a transparent material that is transparent to the wavelength of light handled by the photoelectric element 11, such as deep ultraviolet rays. As an example, the cover member 30 is preferably made of a transparent material having a transmittance of 70% or more for light of wavelengths handled by the photoelectric element 11 when formed into a plate with a thickness of 0.5 mm. Transparent materials include, for example, SiO ₂ —B ₂ O ₃ —RO (R is Mg, Ca, Sr or Ba) glass, SiO ₂ —B ₂ O ₃ —R′ ₂ O (R′ is Li, Na or Ka ) type glass, SiO ₂ —B ₂ O ₃ —RO—R′ ₂ O type glass, SnO—P ₂ O ₅ type glass, TeO ₂ type glass, or Bi ₂ O ₃ type glass.

The cover member 30 is a plate-like member that is rectangular in plan view, and has a size that can close the recess 24 . The cover member 30 has a light-transmitting portion 31 through which light passes, and a joint portion 32 joined to the tip surface 23 of the peripheral wall 22 of the airtight package 12 . The translucent portion 31 is a central portion of the cover member 30 and faces the recess 24 . The joint portion 32 is a peripheral edge portion of the cover member 30 and faces the tip surface 23 of the peripheral wall 22 of the package base material 20 . The cover member 30 is formed by, for example, mold pressing, grinding, polishing, etching, or the like. In the following description, the surface of the cover member 30 facing the package base 20 is also called "inner surface", and the surface opposite to the inner surface is also called "outer surface".

The translucent portion 31 has a flat plate shape. The thickness of the translucent portion 31 is preferably about 0.1 mm to 2.0 mm so as not to reduce translucency.
The joint portion 32 includes a first joint portion 33 that contacts the first tip surface 25 and a second joint portion 34 that is joined to the second tip surface 26 via the joining layer 40 . The first joint portion 33 protrudes from the second joint portion 34 on the inner surface of the cover member 30 . That is, a step is provided between the first joint portion 33 and the second joint portion 34 . The outer surface and inner surface of the first joint portion 33 and the second joint portion 34 are planar. That is, in the joint portion 32 , the second joint portion 34 is thinner than the first joint portion 33 .

Further, the outer surfaces of the translucent portion 31 and the joint portion 32 (the first joint portion 33 and the second joint portion 34) are continuous so as to exist on the same plane, and the inner surfaces of the translucent portion 31 and the first joint portion 33 are Contiguous so as to exist on the same plane. That is, the translucent portion 31 and the first joint portion 33 have the same thickness. As an example, it is preferable that the first joint portion 33 has a thickness of approximately 0.1 mm to 2.0 mm, and the second joint portion 34 is slightly thinner than the first joint portion 33 .

The bonding layer 40 is formed, for example, by heating a glass paste containing low melting point glass powder. The low melting point glass powder may be, for example, Bi ₂ O ₃ -based glass powder, SnO—P ₂ O ₅ -based glass powder, or V ₂ O ₅ -TeO ₂ -based glass powder. The glass paste may contain a low-expansion refractory filler, a laser light absorbing material, and the like in addition to the low-melting-point glass powder.

The bonding layer 40 is formed along the entire circumference of the peripheral wall 22 between the front end surface 23 of the package base material 20 and the bonding portion 32 of the cover member 30 . In a plan view of the airtight package 12 , the formation range of the bonding layer 40 overlaps the front end surface 23 of the peripheral wall 22 of the package base 20 and overlaps the formation range of the bonding portion 32 of the cover member 30 . Specifically, the formation range of the bonding layer 40 is narrower than the tip surface 23 of the peripheral wall 22 and narrower than the formation range of the bonding portion 32 . Therefore, the width W1 of the bonding layer 40 is less than the width W2 of the peripheral wall 22 and the bonding portion 32, as shown in FIG. 1(a). The bonding layer 40 preferably has a thickness of several μm to several tens of μm.

Next, a method of manufacturing the electronic device 10 (hermetic package 12) will be described with reference to FIGS. It is assumed that the photoelectric element 11, the package substrate 20 and the cover member 30 have already been prepared.

As shown in FIG. 2(a), the glass paste 41 is applied in a ring shape (frame shape in this embodiment) on the inner surface of the second joint portion 34 of the cover member 30 (application step). The glass paste 41 may be applied to the cover member 30 by, for example, screen printing, offset printing, letterpress printing, inkjet printing, or the like.

After applying the glass paste 41 to the cover member 30, a so-called calcination process may be performed. Specifically, the cover member 30 coated with the glass paste 41 is put into a heating furnace or the like to be heated, and the binder contained in the glass paste 41 is removed while the glass paste 41 is temporarily solidified. good too.

Then, as shown in FIG. 2B, after the photoelectric element 11 is accommodated in the concave portion 24 of the package base material 20, the cover member 30 is arranged on the package base material 20 (placement step). In the arranging step, the cover member 30 is placed on the package base material such that the first joint portion 33 faces the first tip surface 25 of the peripheral wall 22 and the second joint portion 34 faces the second tip surface 26 of the peripheral wall 22 . 20. Then, the glass paste 41 applied to the second joint portion 34 of the cover member 30 contacts the second end surface 26 of the peripheral wall 22 of the package base material 20 . After that, the glass paste 41 is heated to soften the glass paste 41 (heating step). The heating of the glass paste 41 is performed, for example, by irradiating the glass paste 41 with a laser beam. The glass paste 41 may be softened to a viscosity that allows it to flow, or may be softened to a viscosity that allows it to spread.

Finally, as shown in FIG. 2(c), the cover member 30 is pressed against the package base material 20 (bonding step). In the bonding process, a compressive load acts on the bonding layer 40, so that the bonding layer 40 tends to expand in a direction intersecting the direction of the load. In this respect, in the present embodiment, the first joint portion 33 of the cover member 30 and the first end surface 25 of the peripheral wall 22 of the package base 20 are in contact with each other, so that the joint layer 40 is less likely to flow toward the recess 24 . In other words, the bonding layer 40 tends to flow in the direction opposite to the concave portion 24 . Therefore, the bonding layer 40 is prevented from protruding into the recess 24 .

Thereafter, the electronic device 10 (airtight package 12) is slowly cooled, and the softened bonding layer 40 is solidified. As a result, the second joint portion 34 of the cover member 30 is joined to the second end face 26 of the peripheral wall 22 of the package base 20 via the joint layer 40 , and the photoelectric element 11 is sealed within the recess 24 .

The action and effect of this embodiment will be described.
(1) In the airtight package 12 , the first joint portion 33 of the cover member 30 contacts the first end surface 25 of the peripheral wall 22 of the package base material 20 . Therefore, even if a compressive load is applied to the bonding layer 40 in order to bond the cover member 30 and the package base 20 , the bonding layer 40 is less likely to flow into the recess 24 . Therefore, the airtight package 12 can prevent the bonding layer 40 from protruding into the recess 24 of the package base 20 .

(2) In the airtight package 12, since the inner surface of the translucent portion 31 and the inner surface of the first joint portion 33 are on the same plane, the cover member 30 can be easily manufactured. For example, it is possible to form the inner surface of the translucent portion 31 and the inner surface of the first joint portion 33 at once through a polishing process or the like.

(3) In the hermetic package 12, since the outer surface of the translucent portion 31 and the outer surface of the joint portion 32 are on the same plane, the cover member 30 can be easily manufactured. For example, it is possible to form the outer surface of the translucent portion 31 and the outer surface of the joint portion 32 at once through a polishing process or the like.

(4) In the airtight package 12, the light-transmitting portion 31 of the cover member 30 has a flat plate shape. Therefore, in the airtight package 12, the translucent portion 31 can function as a mere glass cover that only covers the concave portion 24. As shown in FIG.

(5) Since the cover member 30 is made of glass, it is easy to form the shape of the cover member 30 of the translucent portion 31 and the joint portion 32 by a manufacturing method such as mold press.

(6) The cover member 30 is bonded to the bonding layer 40 at two surfaces, the side surface of the first bonding portion 33 and the bottom surface of the second bonding portion 34, which intersect each other. Therefore, the airtight package 12 can increase the bonding strength between the cover member 30 and the bonding layer 40 .

(7) In the application step, when the glass paste 41 is applied to the tip surface 23 of the peripheral wall 22 of the package base material 20, the boundary between the first tip surface 25 and the second tip surface 26 is not clear. A glass paste 41 may be applied to the tip surface 25 . In this case, the first joint portion 33 of the cover member 30 does not come into contact with the first end face 25 of the peripheral wall 22 of the package base 20 , and the joint layer 40 may protrude into the recess 24 . In this regard, in the present embodiment, the glass paste 41 is applied to the first joint portion 33 of the cover member 30 and the stepped second joint portion 34 in the coating step. Therefore, the occurrence of the above situation can be avoided.

This embodiment can be implemented with the following modifications. This embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
- As shown in FIG. 3A, the electronic device 10 (airtight package 12) may be an electronic device 10A (airtight package 12A) according to the first modified example. A cover member 30A of the airtight package 12A has an optical element 35 such as a diffraction grating or a moth-eye structure in the translucent portion 31A. According to this, the airtight package 12 can provide the light transmitting portion 31A with an optical function such as dispersing, refracting, or diffracting incident light.

In addition, the airtight package 12A is arranged on the bottom wall 21 at the point where the first joint portion 33 of the cover member 30 and the first end face 25 of the peripheral wall 22 of the package base 20 come into contact, as in the above embodiment. The distance from the photoelectric element 11 to the translucent portion 31 (optical element) of the cover member 30 tends to be fixed. Therefore, the hermetic package 12A makes it easy to manage the distance between the photoelectric element 11 and the optical element 35 that affects the performance of the electronic device 10A.

- In the 1st modification shown to Fig.3 (a), the optical element 35 is good also as a lens. In this case, the lens is preferably a thin lens such as a Fresnel lens in order to suppress the protrusion amount of the joint portion 32 of the cover member 30 . Furthermore, in this case, the thickness of the translucent portion 31 may be greater than or equal to the thickness of the joint portion 32 . The optical element 35 may be configured integrally with the cover member 30A by integral molding or post-processing, or may be configured by attaching a separate component to the translucent portion 31A.

- As shown in FIG. 3B, the electronic device 10 (airtight package 12) may be an electronic device 10B (airtight package 12B) according to the second modified example. When a third tip surface 27 is an outer portion of the tip surface 23 of the peripheral wall 22 of the package base 20 that is farther from the concave portion 24 than the first tip surface 25 and the second tip surface 26, the cover member 30B of the airtight package 12B. The joint portion 32</b>B has a first joint portion 33 , a second joint portion 34 , and a third joint portion 36 that contacts the third tip surface 27 . According to this, the hermetic package 12B can suppress not only the recess 24 but also the protrusion of the bonding layer 40 to the outside of the hermetic package 12B. However, it is preferable that the application amount and application position of the glass paste 41 forming the bonding layer 40 are determined in detail according to the volume of the space in which the bonding layer 40 is formed.

- In the above-described embodiment, the flat surface does not mean only a perfect flat surface without unevenness on the surface, but may have appropriate unevenness in relation to processing or the like.
- The shape of the cover member 30 may be changed as appropriate. For example, the outer surface of the translucent portion 31 and the outer surface of the joint portion 32 may not be coplanar, and the inner surface of the translucent portion 31 and the inner surface of the first joint portion 33 may not be coplanar.

- The size and shape of the electronic device 10 (airtight package 12) may be changed as appropriate. For example, the electronic device 10 (airtight package 12) may be circular in plan view.

- The cover member 30 may be made of a transparent material such as resin or ceramic. In this case, the bonding layer 40 may be formed using an adhesive, solder, or the like.
- In the heating process, the glass paste 41 may not be heated using a laser beam. For example, in the heating step, an electric heater or the like may be used to heat the glass paste 41 .

DESCRIPTION OF SYMBOLS 10, 10A, 10B... Electronic device, 11... Photoelectric element, 12, 12A, 12B... Airtight package, 20... Package base material, 21... Bottom wall, 22... Peripheral wall, 23... Tip surface, 24... Recessed part, 25... Third 1 tip face 26 second tip face 27 third tip face 30 cover member 31 translucent portion 32 joint portion 33 first joint portion 34 second joint portion 35 Optical element 36 Third joint portion 40 Joint layer 41 Glass paste W1, W2 Width.

Claims (7)

a package base having a bottom wall and a peripheral wall extending from the bottom wall and capable of accommodating a photoelectric element in a recess surrounded by the bottom wall and the peripheral wall;
a cover member that is translucent and closes the recess;
a bonding layer that bonds the package base material and the cover member,
the cover member has a translucent portion facing the recess and a joint portion facing the distal end surface of the peripheral wall;
In the distal end surface of the peripheral wall, when the inner portion near the recess is defined as a first distal end surface and the outer portion far from the recessed portion is defined as a second distal end surface,
The joint includes a first joint that contacts the first tip surface and a second joint that is joined to the second tip surface via the joining layer ,
The bonding layer is made of glass, and is located closer to the center than either the outer edge of the second tip surface or the outer edge of the second bonding portion in a plan view.
airtight package. In the cover member, when the surface facing the package substrate is the inner surface,
2. The hermetic package according to claim 1, wherein the inner surface of the translucent portion and the inner surface of the first joint portion are on the same plane. In the cover member, when the surface facing the package substrate is the inner surface and the surface opposite to the inner surface is the outer surface,
3. The airtight package according to claim 1, wherein the outer surface of the translucent portion and the outer surface of the joint portion are on the same plane. The airtight package according to any one of claims 1 to 3, wherein the translucent portion has a flat plate shape. The airtight package according to any one of claims 1 to 3, wherein the translucent portion has an optical element. The airtight package according to any one of claims 1 to 5, wherein the cover member is glass. A method for manufacturing an airtight package according to any one of claims 1 to 6,
an arrangement step of arranging the cover member on the peripheral wall of the package base so that the joint portion of the cover member faces the tip surface of the peripheral wall of the package base;
With the first joint portion of the cover member in contact with the first end surface of the peripheral wall of the package base material, the second joint portion of the cover member is connected to the second peripheral wall of the package base material. A method of manufacturing an airtight package, comprising: a bonding step of bonding to the tip surface via the bonding layer.

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