TW202008619A - Optical packaging - Google Patents

Abstract

The present invention is an optical package including: The circuit board has a concave portion on the upper surface and an optical element in the concave portion; The base body of the inorganic material is arranged on the circuit board in such a manner as to cover the opening of the recess; and A metal layer that joins the base of the inorganic material to the circuit board; and In a cross section parallel to the stacking direction of the circuit board and the base of the inorganic material and passing through the recess, The distance between the end of the outer periphery of the circuit board and the metal layer and the circuit board is L1, which is the distance between the ends of the outer periphery of the circuit board The distance between the end of the outer peripheral side of the circuit board and the metal layer and the base of the inorganic material is the distance between the end of the outer peripheral side of the circuit board, that is, L2, The distance between the end of the circuit board on the outer peripheral side and the metal layer and the base of the inorganic material is the distance between the end on the side of the recess, that is, L3, and L4 is the distance between the end of the outer peripheral side of the circuit board and the end of the circuit board that is located on the side of the recess The relationship of L1<L2<L3<L4 is satisfied.

Description

Optical packaging

The invention relates to an optical package.

Since the past, there have been cases where an optical element such as a light-emitting diode is placed in a recess of a circuit board, and the opening of the recess is sealed with a window material provided with a transparent resin base material and used as an optical package.

In this case, the window material is bonded to the circuit board with an adhesive made of resin or the like. However, depending on the type of optical element, etc., it is required to improve the hermeticity. Therefore, it has been studied to use a metal material instead of an adhesive made of resin to join the circuit board and the window material.

For example, Patent Literature 1 discloses a light-emitting device including: a mounting substrate; an ultraviolet light-emitting element mounted on the mounting substrate; and a spacer disposed on the mounting substrate and formed with the ultraviolet rays A through-hole through which the light-emitting element is exposed; and a cover, which is arranged on the spacer in such a manner as to cover the through-hole of the spacer; and the ultraviolet light-emitting element has an emission peak wavelength in the ultraviolet wavelength region, and the mounting substrate A support and a first bonding metal layer supported by the support are provided. The spacer includes: a spacer body formed of Si; and a second bonding metal layer formed in the spacer body and The opposing surface side of the mounting substrate faces the first bonding metal layer of the mounting substrate and is formed along the entire circumference of the outer periphery of the opposing surface; and the through hole is formed in the spacer body, The opening area of the through-hole gradually increases as the distance from the mounting substrate increases, the cover is formed of glass that transmits ultraviolet radiation radiated from the ultraviolet light-emitting element, the spacer and the cover are directly joined, and the spacer is separated by AuSn The second bonding metal layer and the first bonding metal layer of the mounting substrate are bonded over the entire circumference of the second bonding metal layer. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 5877487

[Problems to be solved by the invention]

In the light-emitting device disclosed in Patent Document 1, the cover and the spacer are directly joined by anodic bonding, but there is a case where the cover is cracked after bonding.

In view of the above-mentioned problems with the prior art, in one aspect of the present invention, an object is to provide an optical package that suppresses cracks in the cover. [Technical means to solve the problem]

In order to solve the above problems, in one aspect of the present invention, an optical package is provided, which includes: A circuit board having a concave portion on the upper surface and an optical element in the concave portion; A base body of an inorganic material, which is arranged on the circuit board so as to cover the opening of the recess; and A metal layer that joins the base of the inorganic material to the circuit board; and In a cross section parallel to the stacking direction of the circuit board and the base of the inorganic material and passing through the recess, The distance between the end of the outer peripheral side of the circuit board and the end of the outer peripheral side of the circuit board in the portion where the metal layer and the circuit board are in contact is L1. The distance between the end of the outer peripheral side of the circuit board and the metal layer and the base of the inorganic material is L2, the distance between the ends of the outer peripheral side of the circuit board The distance between the end of the circuit board on the outer peripheral side and the end of the metal layer and the base of the inorganic material on the side of the recess is L3, and L4 is the distance between the end portion of the outer peripheral side of the circuit board and the end portion located on the concave portion side of the portion where the metal layer and the circuit board are in contact The relationship of L1<L2<L3<L4 is satisfied. [Effect of invention]

According to one aspect of the present invention, it is possible to provide an optical package that suppresses cracks in the cover.

Hereinafter, the embodiments for implementing the present invention will be described with reference to the drawings. However, the present invention is not limited by the following embodiments, and various changes and substitutions can be added to the following embodiments without departing from the scope of the present invention. [Optical Packaging] The optical package of this embodiment will be described.

The optical package of this embodiment may include: a circuit board having a concave portion on the upper surface and an optical element in the concave portion; a base of an inorganic material, which is arranged on the circuit board so as to cover the opening of the concave portion; and a metal layer , Which joins the base of the inorganic material to the circuit board. Moreover, in the case where the thermal expansion rate of the insulating material of the circuit board is higher than the thermal expansion rate of the material of the inorganic material matrix, the metal layer may have a cross section parallel to the lamination direction of the circuit substrate and the inorganic material matrix and passing through the recess Specific shape. Specifically, in this cross-section, L1 and L2 can satisfy the relationship of L1<L2. The above-mentioned L1 is the portion where the end of the outer peripheral side of the circuit substrate is in contact with the metal layer and the circuit substrate. The distance between the ends, the above L2 is the distance between the ends of the outer peripheral side of the circuit board and the ends of the outer peripheral side of the circuit board in the portion where the metal layer and the base of the inorganic material are in contact.

Furthermore, in another configuration example, the optical package of this embodiment may include: a circuit board having a concave portion on the upper surface and an optical element in the concave portion; and a base body of an inorganic material arranged so as to cover the opening of the concave portion On the circuit board; and a metal layer, which joins the base of the inorganic material to the circuit board.

Moreover, in the case where the thermal expansion coefficient of the insulating material of the circuit substrate does not reach the thermal expansion coefficient of the material of the inorganic material matrix, the metal layer may have a cross section parallel to the lamination direction of the circuit substrate and the inorganic material matrix and passing through the recess Specific shape. Specifically, in this cross-section, L3 and L4 can satisfy the relationship of L3<L4. The above-mentioned L3 is the portion of the circuit board where the end of the outer peripheral side is in contact with the metal layer and the base of the inorganic material on the concave side For the distance between the end portions, the above L4 is the distance between the end portions on the side of the concave portion of the portion where the end portions of the outer peripheral side of the circuit board are in contact with the metal layer and the circuit board.

An example of the configuration of the optical package of this embodiment will be described using FIGS. 1(A) and 1(B).

FIG. 1(A) schematically shows a cross-sectional view of the optical package of this embodiment in a plane parallel to the stacking direction of a base of an inorganic material and a circuit board provided with an optical element and passing through the following recess. To illustrate the composition of the metal layer, the thickness of the metal layer is thicker than other components compared to actual optical packaging.

The optical package 10 of the present embodiment has a base 11 of an inorganic material as a cover, and a circuit board 12 having a recess 121A on the upper surface and an optical element 122 in the recess 121A. The base 11 of the inorganic material is arranged on the circuit board 12 so as to cover the opening of the recess 121A.

Furthermore, it may have a metal layer 13 that joins the base 11 of an inorganic material to the circuit board 12.

The shape of the optical package of this embodiment is not particularly limited, as long as the base 11 having the inorganic material, the circuit board 12, and the metal layer 13 are used as described above, and the base 11 of the inorganic material and the circuit board 12 are separated by the metal layer 13 The method of joining is sufficient.

FIG. 1(B) shows the top view of FIG. 1(A), that is, the view viewed along the square arrow A in FIG. 1(A). In addition, FIG. 1(B) also shows the members observed through the base 11 of the inorganic material. As shown in FIG. 1(B), when the base 11 of the inorganic material is viewed from the upper surface side, it may be polygonal such as a quadrangle. The base 11 of the inorganic material when viewed from the upper surface side is not limited to this form, and may be, for example, a circular shape or the like. In addition, the metal layer 13 may have an opening corresponding to the recess 121A of the circuit board 12 in the center, and have a band shape that surrounds the opening along the outer periphery of the base 11 of the inorganic material. In addition, the circuit board 12 may have an outer shape corresponding to the base 11 of the inorganic material.

In addition, in FIGS. 1(A) and 1(B), the base 11 of the inorganic material is larger than the metal layer 13, but it is not limited to this form. For example, the outer periphery of the base 11 of the inorganic material may be formed so that the outer periphery of the metal layer 13 coincides.

Hereinafter, each member will be described. (Matrix of inorganic materials) The base 11 of the inorganic material is not particularly limited, any material can be used, and any shape can be used.

However, in the case of making an optical package, the base 11 of the inorganic material is preferably a light in a wavelength region that is required to be transmitted among the light related to the optical element included in the circuit board (hereinafter, described as "desired The light in the wavelength region"), the material or its thickness is selected in such a way that the transmittance is sufficiently high. For example, for light in a desired wavelength region, the transmittance is preferably 50% or more, more preferably 70% or more, and further preferably 80% or more, particularly preferably 90% or more.

Regarding the matrix 11 of the inorganic material, when the light in the desired wavelength region is light in the infrared region, for example, for light with a wavelength of 0.7 μm or more and 1 mm or less, the transmittance is preferably 50% or more, and more preferably It is 70% or more, more preferably 80% or more, and particularly preferably 90% or more.

Also, regarding the base 11 of the inorganic material, when the light in the desired wavelength region is light in the visible region (blue to green to red), for example, for light with a wavelength in the range of 380 nm or more and 800 nm or less, the transmittance It is preferably 50% or more, more preferably 70% or more, still more preferably 80% or more, and particularly preferably 90% or more.

Regarding the matrix 11 of the inorganic material, when the light in the desired wavelength region is light in the ultraviolet region, for example, for light in the wavelength range of 200 nm or more and 380 nm or less, the transmittance is preferably 50% or more, more preferably It is 70% or more, more preferably 80% or more, and particularly preferably 90% or more.

Regarding the matrix 11 of the inorganic material, when the light in the desired wavelength region is UV-A light in the ultraviolet region, for example, for light with a wavelength of 315 nm or more and 380 nm or less, the transmittance is preferably 50% The above is more preferably 70% or more, further preferably 80% or more, and particularly preferably 90% or more.

Regarding the matrix 11 of the inorganic material, when the light in the desired wavelength region is UV-B light in the ultraviolet region, for example, for light in the wavelength range from 280 nm to 315 nm, the transmittance is preferably 50% The above is more preferably 70% or more, further preferably 80% or more, and particularly preferably 90% or more.

Regarding the base 11 of the inorganic material, when the light in the desired wavelength region is UV-C light in the ultraviolet region, for example, for light in the wavelength range of 200 nm or more and 280 nm or less, the transmittance is preferably 50% The above is more preferably 70% or more, further preferably 80% or more, and particularly preferably 90% or more.

In addition, the transmittance of the base 11 of the inorganic material can be measured in accordance with JIS K 7361-1 (1997).

The material of the base 11 of the inorganic material can be arbitrarily selected as already described, and is not particularly limited, but from the viewpoint of improving the total airtightness or durability, for example, quartz, glass, etc. can be preferably used . Quartz includes quartz glass or SiO ₂ containing 90% by mass or more. Examples of the glass include soda lime glass, aluminosilicate glass, borosilicate glass, alkali-free glass, crystallized glass, and high refractive index glass (nd≧1.5). In addition, the material used as the base of the inorganic material is not limited to one kind, and two or more kinds of materials may be used in combination. Therefore, for example, as the material of the base 11 of the inorganic material, for example, a material selected from quartz, soda lime glass, aluminosilicate glass, borosilicate glass, alkali-free glass, crystallized glass, and high refractive index glass can be preferably used One or more materials in (nd≧1.5).

In the case of using glass as the material of the base 11 of the inorganic material, the base 11 of the inorganic material may also be subjected to chemical strengthening treatment.

The thickness of the base 11 of the inorganic material is also not particularly limited. For example, it is preferably set to 0.03 mm or more, more preferably set to 0.05 mm or more, further preferably set to 0.1 mm or more, and particularly preferably set to 0.3 mm the above.

By setting the thickness of the base 11 of the inorganic material to 0.03 mm or more, the strength required for the optical package can be fully exerted, and in particular, moisture and the like can be prevented from passing through the surface of the base 11 of the inorganic material of the window material to the optical element side. By setting the thickness of the base 11 of the inorganic material to 0.3 mm or more as described above, the strength of the optical package can be particularly improved, which is preferable.

The upper limit of the thickness of the base 11 of the inorganic material is also not particularly limited. For example, it is preferably 5 mm or less, more preferably 3 mm or less, and further preferably 1 mm or less. The reason is that by setting the thickness of the base 11 of the inorganic material to 5 mm or less, the transmittance of light in the desired wavelength region can be sufficiently improved. By setting the thickness of the base 11 of the inorganic material to 1 mm or less, the height of the optical package can be reduced in particular, which is more preferable.

Furthermore, the shape of the base 11 of the inorganic material is not particularly limited, and the thickness need not be uniform. Therefore, when the thickness of the inorganic material substrate is not uniform, it is preferable that the thickness of the portion of the inorganic material substrate that is located on the optical path of the light associated with the optical element when at least the optical package is made falls within the above range It is more preferable that the thickness of the matrix of the inorganic material is within the above range at any part.

The shape of the base 11 of the inorganic material is not particularly limited as described above. For example, a plate-like shape or a shape in which the lens is integrated, that is, a shape including concave portions or convex portions derived from the lens may be used. Specifically, for example, one surface 11a of the base 11 of the inorganic material is a flat surface and the other surface 11b has a convex portion or a concave portion, or the shape of the one surface 11a and the other surface 11b is opposite to the shape. In addition, the surface 11a of the base 11 of the inorganic material has a convex portion and the other surface 11b has a concave portion, or the shape of the one surface 11a and the shape of the other surface 11b is opposite to this shape. Furthermore, it can be exemplified that each of the one surface 11a and the other surface 11b of the base 11 of the inorganic material has a convex portion or a concave portion.

Furthermore, even when the surface 11a of the base 11 of the inorganic material has a convex portion or a concave portion, the portion of the surface 11a of the base 11 of the inorganic material where the metal layer 13 is disposed is, for example, when manufacturing a plurality of window materials, etc. The shape of the metal layer 13 between the window materials is suppressed, and it is preferably flat.

As shown in FIG. 1(A), the surface 11a of the base 11 of the inorganic material becomes the surface facing the optical element 122 when the optical package is made. The other surface 11b of the base 11 of the inorganic material is the surface exposed to the outside when the optical package is made.

Depending on the form of the optical package, there are cases where the size of the base of the inorganic material is very small. Therefore, when cutting the material before cutting the base material of the inorganic material into a desired size, it is preferable to use a cutting method using laser light. In the case of cutting by this method, as shown in FIG. 2, the side surface of the base 11 of the inorganic material has a linear pattern 111 along the outer periphery of the one surface 11 a corresponding to the focal position of the laser light.

In addition, the method of cutting the base 11 of the inorganic material is not limited to the above example, and any method can be used for cutting. In the case of cutting by a method other than the above-mentioned cutting method, the side surface of the base 11 of the inorganic material, that is, the cut surface may have a different cross-sectional shape from the above-mentioned case. As another cutting method, for example, a wafer dicing machine or a wire dicing machine can be mentioned. These cutting methods are effective when the thickness of the base material of the inorganic material before cutting is 1 mm or more.

An anti-reflection film may also be pre-arranged on the surface of the base 11 of inorganic material. By configuring the anti-reflection film, when the optical package is made, the light from the optical element or the outside can be suppressed from being reflected on the surface of the base 11 of the inorganic material, thereby improving the transmittance of the light from the optical element or the outside. good. The anti-reflection film is not particularly limited, and for example, a multilayer film can be used. The multilayer film can be a layer made of one or more materials selected from alumina (aluminum oxide, Al ₂ O ₃ ), hafnium oxide (HfO ₂ ), titanium oxide (TiO ₂ ), that is, layer 1 and silica The layer of (silicon oxide, SiO ₂ ) is a film formed by alternately laminating the second layer. The number of layers constituting the multilayer film is not particularly limited. For example, the first layer and the second layer are set as one group. The multilayer film preferably has at least one group of the first layer and the second layer, more preferably With more than 2 groups. The reason for this is that, since the multilayer film has one or more sets of the first layer and the second layer, it is possible to particularly suppress light reflection on the surface of the base 11 of the inorganic material.

The upper limit of the number of layers constituting the multilayer film is also not particularly limited, but for example, from the viewpoint of productivity and the like, it is preferable to have a group of 4 or less of the above-mentioned first layer and second layer.

In the case of having an anti-reflection film, the anti-reflection film is preferably arranged on at least one side 11a of the base 11 of the inorganic material, more preferably on both sides of one side 11a and the other side 11b. When antireflection films are arranged on both surfaces of one surface 11a and the other surface 11b, the configurations of the two antireflection films may be different, but from the viewpoint of productivity and the like, it is preferable that the antireflection films have the same configuration.

When using the above-mentioned multilayer film as an anti-reflection film, it is preferable that the second layer of silica is located on the outermost surface. The reason is that the second layer of silica is located on the outermost surface of the antireflection film, and the surface of the antireflection film becomes similar to the surface of the glass substrate, so that the durability or the adhesion to the metal layer 13 becomes particularly high , And better. (Circuit board) The circuit board 12 is not particularly limited, and various circuit boards including an insulating base 121 and wiring (not shown) that supplies power to the optical element 122 can be used. Furthermore, the insulating material of the circuit board 12 refers to the material of the insulating base 121.

The material of the insulating substrate 121 is not particularly limited, but when the inorganic material base 11 is joined via the metal layer 13, in order to increase the space surrounded by the inorganic material base 11, the circuit board 12, and the metal layer 13 For complete hermeticity, the circuit board 12 preferably has an insulating base 121 made of ceramic. That is, the insulating material of the circuit board 12 is preferably ceramic.

The ceramic material used for the insulating substrate 121 of the circuit board 12 is not particularly limited, and examples thereof include alumina (aluminum oxide, Al ₂ O ₃ ), aluminum nitride (AlN), and LTCC (Low Temperature Co-fired Ceramics).

In the case where the insulating substrate 121 of the circuit board 12 is made into the optical package 10, it is preferable to use the base 11 of the inorganic material, the insulating substrate 121, and the metal layer 13 in the portion for disposing the optical element 122 The way to form a closed space. Therefore, the insulating substrate 121 preferably has an opening in the center of the upper surface 1211 and has a recess 121A that is a non-through hole including the opening. In addition, the upper surface 1211 of the insulating substrate 121 is the surface facing the base 11 of the inorganic material when the optical package 10 is made, and may also be referred to as the surface on the side joined to the base 11 of the inorganic material.

The wall portion 121B surrounding the concave portion 121A may have a shape corresponding to the metal layer 13 in order to support the metal layer 13 when the optical package is made.

The optical element 122 disposed on the circuit board 12 is not particularly limited, and for example, a light emitting element such as a light emitting diode or a light receiving element can be used.

Furthermore, when the optical element 122 is a light-emitting element, the wavelength region of light emitted by the light-emitting element is not particularly limited. Therefore, a light-emitting element that emits light in an arbitrary wavelength region selected from the range of ultraviolet light to infrared light, that is, an arbitrary wavelength region selected from the range of wavelengths of 200 nm or more and 1 mm or less, for example, can be used.

However, according to the optical package of this embodiment, the base system of the inorganic material that is the member that transmits the light from the light-emitting element is formed of the inorganic material instead of the transparent resin. Therefore, compared with the case where a substrate made of a transparent resin is used, the full airtightness can be improved, and further the deterioration of the window material caused by the light from the light emitting element can be suppressed. Therefore, when the optical element is a light-emitting element, and when a light-emitting element that particularly requires airtightness or a light-emitting element that emits light that deteriorates easily with resin is used, the optical package of this embodiment can be used particularly The higher the effect, the better. Examples of light-emitting elements that require airtightness in particular include UV-C light-emitting elements that emit light in a wavelength range of 200 nm or more and 280 nm or less. In addition, as the light-emitting element that emits light in which deterioration of the resin easily progresses, a light-emitting element that emits light with high output such as laser light can be cited. Therefore, when the optical element 122 is a light-emitting element, as the light-emitting element, in particular, from the viewpoint of exerting a higher effect, a light-emitting element emitting UV-C, a laser, or the like can be preferably used. (Metal layer) The metal layer 13 is disposed between the base 11 of the inorganic material and the circuit board 12, and can bond the base 11 of the inorganic material and the circuit board 12.

The inventors of the present invention and others have intensively studied the cause of the occurrence of cracks (cracking) in the base of the inorganic material when the base of the inorganic material and the circuit board are bonded to form an optical package.

The metal layer 13 may include, for example, a solder layer as described below, and the base body 11 of the inorganic material and the circuit board 12 may be cooled by heating above the melting point of the solder of the solder layer while the two members are in contact with the metal layer 13 And joined.

According to the research by the inventors of the present invention, when the thermal expansion coefficients of the material of the base 11 of the inorganic material and the insulating material of the circuit board 12 are different, in order to join the two members and then cool after heating, the two members The degree of contraction varies. In addition, since a tensile stress is applied to a part of the junction between the base 11 of the inorganic material and the metal layer 13, the base 11 of the inorganic material may be cracked.

Therefore, after further research, it was found that the shape of the metal layer joining the base material of the inorganic material and the circuit board is set by the thermal expansion coefficient of the material of the base material 11 of the inorganic material and the thermal expansion coefficient of the insulating material of the circuit board 12 With a specific shape, the generation of cracks can be suppressed, and the present invention has been completed.

In order to explain the shape of an appropriate metal layer, FIG. 3 shows an enlarged view of a region surrounded by a broken line B in FIG. 1(A) and is schematically shown. That is, FIG. 3 shows a cross section parallel to the lamination direction of the circuit board 12 and the base 11 of inorganic material and passing through the recess 121A. In addition, as described below, the metal layer 13 may also include a plurality of layers. However, the shape of the metal layer 13 as a whole is shown in FIG. 3, so the layers are not distinguished and are shown in an integrated form.

According to the research of the inventors of the present invention, when the thermal expansion rate of the insulating material of the circuit board is higher than the thermal expansion rate of the base material of the inorganic material, it is preferable to parallel the circuit board 12 and In the cross section of the substrate 11 of the inorganic material in the stacking direction and passing through the recess 121A, L1 and L2 in the figure satisfy the relationship of L1<L2.

As shown in FIG. 3, L1 is the distance between the point 13A which is the end of the circuit board 12 on the outer peripheral side of the portion where the end 1212 on the outer peripheral side of the circuit board 12 is in contact with the metal layer 13 and the circuit board 12. In addition, L2 is the distance between the point 13B, which is the end portion of the circuit board 12 on the outer peripheral side of the portion where the end portion 1212 of the outer peripheral side of the circuit board 12 is in contact with the metal layer 13 and the base 11 of the inorganic material.

In the case where the thermal expansion coefficient of the insulating material of the circuit board 12 is greater than the thermal expansion coefficient of the material of the base 11 of the inorganic material, if the two members are cooled after being heated, the displacement of the circuit board 12 is greater than that of the inorganic material基体11。 The substrate 11. In addition, when the shape of the metal layer is L2<L1, the point on the outer peripheral side of the circuit board 12 that is the point 13B in the portion where the metal layer 13 is in contact with the base 11 of the inorganic material is along the line segment 13B -13A generates tensile stress by peeling the metal layer 13 from the base 11 of the inorganic material. Therefore, in this case, the base 11 of the inorganic material may crack.

On the other hand, when the thermal expansion coefficient of the insulating material of the circuit board 12 is greater than the thermal expansion coefficient of the material of the base 11 of the inorganic material, the shape of the metal layer 13 can be selected by satisfying the relationship of L1<L2 to prevent heating 3. The above-mentioned tensile stress occurs at point 13B during cooling. Therefore, it is possible to suppress cracks in the base 11 of the inorganic material.

When the thermal expansion coefficient of the insulating material of the circuit board 12 is equal to the thermal expansion coefficient of the material of the base 11 of the inorganic material, there is no difference in the degree of shrinkage when the two members are heated and cooled. However, in this case, also by selecting the shape of the metal layer 13 so as to satisfy the relationship of L1<L2, it is possible to more reliably prevent the above-mentioned tensile stress from occurring at point 13B during heating and cooling, which can be suppressed by The base 11 of the inorganic material is broken.

Therefore, as described above, when the thermal expansion rate of the insulating material of the circuit board 12 is higher than the thermal expansion rate of the material of the base 11 of the inorganic material, the shape of the metal layer 13 is preferably selected to satisfy the relationship of L1<L2 .

In addition, the preferred ranges of L1 and L2 are 0.05 mm≦L1≦0.15 mm, 0.15 mm≦L2≦0.50 mm.

Furthermore, in this case, the shape of the other side surface of the cross-sectional shape of the metal layer 13, that is, the shape of the point 13C and the point 13D side is not particularly limited, and may be any shape.

In addition, when the thermal expansion coefficient of the insulating material of the circuit board 12 does not reach the thermal expansion coefficient of the material of the base 11 of the inorganic material, it is preferable to stack the layer parallel to the circuit board 12 and the base 11 of the inorganic material as shown in FIG. 3 In the direction and the cross section passing through the recess 121A, L3 and L4 in the figure satisfy the relationship of L3<L4.

As shown in FIG. 3, L3 is the distance between the point 13C, which is the end on the side of the recess 121A, of the portion where the end 1212 on the outer peripheral side of the circuit board 12 is in contact with the metal layer 13 and the base 11 of the inorganic material. In addition, L4 is the distance between the point 13D, which is the end located on the side of the recess 121A, of the portion where the end 1212 on the outer peripheral side of the circuit board 12 is in contact with the metal layer 13 and the circuit board 12.

In the case where the thermal expansion coefficient of the insulating material of the circuit board does not reach the thermal expansion coefficient of the material of the base material of the inorganic material, the displacement amount of the base material 11 of the inorganic material is greater than that of the circuit board if the two components are cooled after being heated 12. Moreover, when the shape of the metal layer is L4<L3, the point 13C on the side of the recess 121A in the portion where the metal layer 13 is in contact with the base 11 of the inorganic material is along the line segment 13C-13D The tensile stress is generated by the metal layer 13 peeling from the base 11 of the inorganic material. Therefore, in this case, the base 11 of the inorganic material may crack.

On the other hand, as already described, when the thermal expansion coefficient of the material of the circuit board 12 does not reach the thermal expansion coefficient of the material of the base 11 of the inorganic material, the shape of the metal layer is selected by satisfying the relationship of L3<L4, It is possible to prevent the above-mentioned tensile stress from occurring at point 13C during heating and cooling. Therefore, it is possible to suppress cracks in the base 11 of the inorganic material.

In addition, the preferred ranges of L3 and L4 are 0.40 mm≦L3≦0.55 mm, 0.45 mm≦L4≦1.00 mm.

In this case, the shape of the side surface of the cross-sectional shape of the metal layer 13, that is, the shape of the point 13A and the point 13B side is not particularly limited, and may be any shape.

However, as far as the relationship between the thermal expansion coefficients of the base 11 of the inorganic material and the circuit board 12 can be prevented from being cracked in the base 11 of the inorganic material, the metal layer 13 in the cross section shown in FIG. 3 is more preferable. The shape satisfies the relationship of L1<L2<L3<L4.

In addition, during heating, it is not necessary to apply heat uniformly to the base 11 of the inorganic material and the circuit board 12, and depending on the application method of heat, there are also thermal expansion coefficients of the base of the inorganic material, the circuit board, and various members during heating and cooling The relationship between the amount of displacement is not as described above. Therefore, from the viewpoint of more reliably preventing cracks in the base of the inorganic material, it is more preferable to have no relation to the thermal expansion coefficient of the base 11 of the inorganic material and the circuit board 12 in the cross section shown in FIG. The shape of 13 satisfies L1<L2<L3<L4.

In general, it is known that when the circuit board 12 is bonded to the base 11 of an inorganic material, when the side shape of the joint portion of the metal layer 13 is corner-filled, the tensile stress generated from the base 11 of the inorganic material can be made Significantly reduced. However, in order to make the side shape of the metal layer fillet-shaped, a member such as a spacer is required between the circuit board 12 and the base 11 of inorganic material, which is the main reason for the complexity of the bonding process or the increase in cost in the manufacture of optical packages . Therefore, as long as the thermal expansion coefficient of the insulating material of the circuit board and the thermal expansion coefficient of the base material of the inorganic material are satisfied, it is sufficient that the above-mentioned L1, L2, or L3, L4 meet the already described range. No particular limitation.

The metal layer 13 may have multiple layers as already described. Hereinafter, a configuration example of the plurality of layers will be described.

The metal layer 13 may have, for example, a base metal layer and a solder layer, as described below, for example, may have a base-side base metal layer 1311 disposed on the base 11 side of the inorganic material via the solder layer 1312 and a circuit substrate 12 side Two kinds of base metal layers on the base metal layer 132 on the circuit board side.

First, the base metal layer disposed on the base side of the inorganic material will be described.

The base metal layer 1311 on the base side may have a function of improving the adhesion between the base 11 of the inorganic material and the solder layer 1312. The configuration of the base metal layer 1311 on the substrate side is not particularly limited, but it is preferable to include a plurality of layers as shown in FIG. 1(A).

The structure of the base metal layer 1311 on the substrate side is not particularly limited, and may include two or three layers, for example. Specifically, for example, a first base-side base metal layer 1311A and a second base-side base metal layer 1311B may be provided in order from the base 11 side of the inorganic material. Furthermore, a third base-side base metal layer 1311C may be further disposed between the second base-side base metal layer 1311B and the solder layer 1312.

The first base metal layer 1311A on the base side may have a function of improving the adhesion between the base 11 of the inorganic material and other layers. The material of the first substrate-side base metal layer 1311A is preferably a material that can improve the adhesion between the inorganic material substrate 11 and other layers, and more preferably a material that also improves airtightness. The first base-side base metal layer 1311A is preferably a layer containing at least one selected from chromium (Cr), titanium (Ti), tungsten (W), and palladium (Pd). The first substrate-side base metal layer 1311A may be a layer composed of one or more materials selected from, for example, chromium (Cr), titanium (Ti), tungsten (W), and palladium (Pd). In addition, in this case, it is not excluded that the first base metal layer 1311A contains unavoidable impurities.

The first substrate-side base metal layer 1311A is more preferably a metal film or metal oxide film of one or more metals selected from chromium (Cr), titanium (Ti), tungsten (W), and palladium (Pd). .

The second substrate-side base metal layer 1311B has a function of improving the adhesion between the solder layer 1312 and other layers, and is preferably set to contain, for example, nickel (Ni), copper (Cu), platinum (Pt), and silver (Ag) One of more than one metal layer. From the viewpoint of suppressing costs in particular, the second base-side base metal layer 1311B is more preferably a layer containing one or more metals selected from nickel (Ni) and copper (Cu).

In addition, the second base-side base metal layer 1311B may be a layer composed of one or more metals selected from, for example, nickel (Ni), copper (Cu), platinum (Pt), and silver (Ag). In this case, from the viewpoint of cost, the second substrate-side base metal layer 1311B is also preferably a layer composed of one or more metals selected from nickel (Ni) and copper (Cu). Furthermore, in any of the above cases, it is not excluded that the second base-side base metal layer 1311B contains unavoidable impurities.

In addition, when the third base-side base metal layer 1311C is further provided, the third base-side base metal layer 1311C is preferably made to contain one or more layers selected from nickel (Ni) and gold (Au), for example. . In particular, when the third base metal layer 1311C is a layer containing nickel (Ni), in order to improve the wettability of the solder, it is preferably a layer containing nickel-boron alloy (Ni-B) , Or a layer composed of Ni-B. By providing the third base-side base metal layer 1311C, for example, the reaction between the base-side base metal layer 1311 and the solder layer 1312 can be particularly suppressed. The third base-side base metal layer 1311C may be a layer composed of one or more metals selected from nickel (Ni) and gold (Au). In this case, it is not excluded that the third base metal layer contains unavoidable impurities.

The thickness of each layer constituting the base-side base metal layer 1311 is not particularly limited, and can be arbitrarily selected.

For example, the thickness of the first substrate-side base metal layer 1311A is preferably 0.03 μm or more from the viewpoint of improving the adhesion to the substrate 11 of an inorganic material. The upper limit of the thickness of the first substrate-side base metal layer 1311A is also not particularly limited, but from the viewpoint of sufficiently reducing the cost, it is preferably 0.2 μm or less.

The thickness of the second substrate-side base metal layer 1311B is preferably 0.1 μm or more from the viewpoint of improving the adhesion with the solder layer 1312 in particular. The upper limit of the thickness of the second substrate-side base metal layer 1311B is also not particularly limited, but from the viewpoint of sufficiently reducing the cost, it is preferably 2.0 μm or less.

In the case where the third base-side base metal layer 1311C is also provided, the thickness is not particularly limited, but from the viewpoint of suppressing the reaction of the base-side base metal layer 1311 and the solder layer 1312 in particular, it is preferably set to 0.05, for example. μm or more. The upper limit of the thickness of the third substrate-side base metal layer 1311C is also not particularly limited, but from the viewpoint of sufficiently reducing the cost, it is preferably 1.0 μm or less.

Next, the solder layer 1312 will be described.

The solder layer 1312 has a function of bonding the base 11 of an inorganic material to the circuit board 12 provided with an optical element when manufacturing an optical package, and the configuration thereof is not particularly limited.

However, the thickness of the solder layer 1312 is preferably 5 μm or more, and more preferably 15 μm or more. The insulating substrate 121 of the circuit board 12 may be formed of a ceramic material as described above. However, when the ceramic material is used for manufacturing, it is usually a casting. Therefore, in many cases, it is difficult to arrange the surface for disposing the metal layer 13 Completely flat. Therefore, it is preferable to set the thickness of the solder layer to 5 μm or more and to be able to absorb the unevenness of the surface of the insulating base material 121 on which the metal layer 13 is arranged.

Furthermore, the thickness of the solder layer 1312 mentioned herein refers to the thickness of the solder layer 1312 at any position of the optical package 10 of this embodiment. Therefore, it means that even in the thinnest portion, the solder layer sufficiently satisfies the thickness range.

The upper limit of the thickness of the solder layer is not particularly limited, and it can be set to, for example, 50 μm or less.

The average value of the thickness of the solder layer 1312 is preferably 5 μm or more, and more preferably 15 μm or more. The reason is that, by setting the average value of the thickness of the solder layer 1312 to 5 μm or more, even if, for example, the joining surface of the circuit board to be joined with the metal layer 13 includes irregularities, the recesses are filled with the material of the solder layer, In particular, it is possible to improve hermeticity.

In addition, the above average value refers to a value of a simple average (sometimes referred to as an arithmetic mean (arithmetic mean) or an additive average (arithmetic average)). In the following, when referred to as "average", it refers to simple average.

In addition, the upper limit of the average value of the thickness of the solder layer 1312 is not particularly limited, but it is preferably 50 μm or less, and more preferably 30 μm or less. The reason for this is that even if the average value of the thickness of the solder layer 1312 exceeds 50 μm and becomes excessively thick, the effect of the full sealing property will not change significantly.

Furthermore, the average value of the thickness of the solder layer 1312 can be determined by using a laser microscope (manufactured by Keyence Corporation, model VK-8510) to measure the thickness of the solder layer 1312 at any plural measurement points, and the average value is obtained. Figure it out. The number of measurement points for measuring the thickness of the solder layer 1312 for calculating the average value is not particularly limited, but for example, it is preferably 2 points or more, and more preferably 4 points or more. The upper limit of the number of measurement points is also not particularly limited, but from the viewpoint of efficiency, it is preferably 10 points or less, and more preferably 8 points or less.

Regarding the solder layer 1312, the deviation of the thickness, that is, the deviation of the thickness from the simple average value is preferably within ±20 μm, and more preferably within ±10 μm.

The reason for this is that, by setting the deviation of the thickness of the solder layer 1312 to within ±20 μm, it is possible to particularly improve the total airtightness between the window material and the circuit board on which the optical element is arranged when manufacturing the optical package, which is preferable .

The deviation of the thickness of the solder layer 1312 within ±20 μm means that the deviation is distributed within a range of -20 μm or more + 20 μm or less.

The deviation of the thickness of the solder layer 1312 can be calculated from the average value of the thickness of the solder layer and the measurement value used when calculating the average value.

The solder layer 1312 may contain various solders (composition for bonding).

The solder used for the solder layer 1312 is not particularly limited. For example, a material with a Young's modulus of 50 GPa or less is preferable, a material with 40 GPa or less is more preferable, and a material with 30 GPa or less is more preferable.

After the optical package is made, for example, when the optical element is made to emit light or extinguished, there may be a temperature change in the solder layer. Moreover, the reason is that by setting the Young's modulus of the solder used for the solder layer to 50 GPa or less, even if the temperature changes occur in the solder layer part, causing expansion and contraction, it is possible to particularly suppress other components. It is better to cause damage etc.

In addition, the reason is that when the Young's modulus of the solder is 50 GPa or less, when the optical package is made, the difference between the thermal expansion of the base 11 of the inorganic material and the circuit board 12 with the optical element can be caused The stress is absorbed in the solder layer 1312 joining the two members, which is preferable.

The lower limit value of the appropriate range of the Young's modulus of the solder used for the solder layer 1312 is not particularly limited, as long as it is greater than 0, for example, it is preferably 10 GPa or more from the viewpoint of improving the total tightness.

The Young's modulus of solder can be calculated based on the tensile test of the solder.

In addition, the melting point of the solder used for the solder layer 1312 is preferably 200°C or higher, and more preferably 230°C or higher. The reason is that when the melting point of the solder is 200° C. or higher, the heat resistance at the time of making an optical package can be sufficiently improved. However, the melting point of the solder used for the solder layer 1312 is preferably 280°C or lower. When manufacturing an optical package, heat treatment is performed to melt at least a part of the solder layer 1312. However, when the melting point of the solder is 280°C or lower, the temperature of the heat treatment can be suppressed to a low level. Therefore, the generation of optical elements and the like can be particularly suppressed. damage. In addition, the reason is that by suppressing the heat treatment temperature to be low, it is possible to reduce the difference in the degree of shrinkage caused by the difference in the thermal expansion rates of the material of the base 11 of the inorganic material and the insulating material of the circuit board 12.

The density of the solder used for the solder layer 1312 is preferably 6.0 g/cm ³ or more, and more preferably 7.0 g/cm ³ or more. The reason for this is that, by setting the density of the solder used for the solder layer 1312 to 6.0 g/cm ³ or more, it is possible to improve the overall hermeticity particularly. The upper limit of the density of the solder used for the solder layer 1312 is not particularly limited, and for example, preferably 10 g/cm ³ or less.

The thermal expansion coefficient of the solder used for the solder layer 1312 is preferably 30 ppm or less, and more preferably 25 ppm or less. The reason is that when the thermal expansion rate of the solder is 30 ppm or less, the shape change caused by the heat generated when the optical package is made and the optical element emits light, etc. can be suppressed, and the damage of the optical package can be more reliably prevented. The lower limit of the thermal expansion coefficient of the solder used for the solder layer 1312 is not particularly limited, but is preferably 0.5 ppm or more.

The solder that can be preferably used for the solder layer 1312 is not particularly limited, and examples thereof include solders selected from the group consisting of tin (Sn)-germanium (Ge)-nickel (Ni) or tin (Sn)-antimony (Sb). One or more types of solder, gold (Au)-tin (Sn) solder, tin (Sn)-silver (Ag)-copper (Cu) solder, etc.

Furthermore, for example, in the case of tin-germanium-nickel solder, tin may be included as a main component. Containing tin as the main component means, for example, the component most contained in the solder, and preferably contains 60% by mass or more of tin in the solder. The tin content of the solder is, for example, more preferably 85.9% by mass or more, further preferably 87.0% by mass or more, and particularly preferably 88.0% by mass or more.

The reason for this is that when the tin content in the solder is 85.9% by mass or more, it exhibits a particularly high effect on the relaxation of the difference in thermal expansion between the member to be joined and the solder, and the decrease in the melting temperature of the solder.

The upper limit of the content of tin in the solder is not particularly limited. For example, it is preferably 99.9% by mass or less, more preferably 99.5% by mass or less, and further preferably 99.3% by mass or less. In addition, the tin-germanium-nickel-based solder may contain one or more components selected from iridium, zinc, and the like in addition to tin, germanium, and nickel.

The content of each component of the tin-antimony solder is not particularly limited. For example, the content of antimony is preferably 1% by mass or more. The reason for this is that antimony has an effect of increasing the solidus temperature in the tin-antimony solder, and by setting the content of antimony to 1% by mass or more, this effect can be exerted particularly, and is preferable.

The upper limit of the antimony content is not particularly limited. For example, it is preferably 40% by mass or less. The reason is that, by setting the content of antimony to 40% by mass or less, it is possible to prevent the solidus temperature from becoming excessively high, and it is possible to produce solder suitable for mounting electronic parts.

The tin-antimony solder may contain tin. Tin can alleviate the difference in thermal expansion between the soldered member such as the circuit board or the base metal layer and the solder. Furthermore, by containing tin as the main component of the solder, the melting point temperature of the solder can be set to about 230°C, which is the melting point temperature of tin.

The tin-antimony solder can also be composed of antimony and tin, and in this case, tin can constitute the remaining portion other than antimony.

The tin-antimony solder may contain any additional components in addition to antimony and tin. For example, it may contain one or more kinds selected from silver (Ag), copper (Cu), and the like. Like antimony, silver or copper has the effect of increasing the solidus temperature of the solder. In this case, tin may constitute the remaining portion other than antimony and any additional components.

A configuration example of the solder that can be preferably used for the solder layer 1312 has been described, but as already described, the solder used for the solder layer 1312 is not limited to the solder.

Next, the base metal layer on the circuit board side disposed on the circuit board side will be described.

The circuit board 12 may have a circuit board-side base metal layer 132 on the upper surface 1211 of the insulating base 121 and the upper surface of the wall 121B.

The base metal layer 132 on the circuit board side can have a function of improving the adhesion between the insulating base material 121 of the circuit board 12 and the solder layer 1312. The specific structure of the base metal layer 132 on the circuit board side is not particularly limited. For example, it may include a base metal layer 132A on the first circuit board side and a base metal layer 132B on the second circuit board side from the insulating base material 121 side of the circuit board 12 3. A layer structure in which the base metal layer 132C on the third circuit board side is sequentially stacked. Here, the example in which the base metal layer 132 on the circuit board side includes three layers is shown here, but it is not limited to this form, and may include one layer, two layers, or four or more layers.

In the case where the circuit substrate side base metal layer 132 includes three layers as described above, for example, the first circuit substrate side base metal layer 132A preferably includes the same metal used to form the wiring (circuit) in the circuit substrate 12 metal. For example, the first circuit board side base metal layer 132A may be a layer containing one or more metals selected from copper (Cu), silver (Ag), and tungsten (W). The first circuit board side base metal layer 132A may be a layer composed of one or more metals selected from copper (Cu), silver (Ag), and tungsten (W). Furthermore, in this case, the case where the base metal layer 132A on the first circuit board side contains unavoidable impurities is not excluded.

The second circuit substrate side base metal layer 132B may be a layer that prevents alloying of the following third circuit substrate side base metal layer 132C and the first circuit substrate side base metal layer 132A, for example, a layer containing nickel (Ni) . The base metal layer 132B on the second circuit board side may be a layer made of nickel (Ni). Furthermore, in this case, the case where the base metal layer 132B on the second circuit substrate side contains unavoidable impurities is not excluded.

The third circuit substrate side base metal layer 132C may be a layer for preventing oxidation of the second circuit substrate side base metal layer 132B, and may be a layer containing gold (Au), for example. The third circuit board side base metal layer 132C may be a layer made of gold (Au). Furthermore, in this case, the case where the base metal layer 132C on the third circuit substrate side contains unavoidable impurities is not excluded.

The thickness of each layer constituting the base metal layer 132 on the circuit board side is not particularly limited, and can be arbitrarily selected.

The thickness of the base metal layer 132A on the first circuit board side is preferably set to 1 μm or more, for example. The upper limit of the thickness of the base metal layer 132A on the first circuit board side is also not particularly limited, but from the viewpoint of sufficiently reducing the cost, it is preferably 20 μm or less.

The thickness of the second circuit substrate side base metal layer 132B is preferably 1 μm or more in terms of suppressing the alloying of the first circuit substrate side base metal layer 132A and the third circuit substrate side base metal layer 132C. The upper limit of the thickness of the base metal layer 132B on the second circuit board side is also not particularly limited, but from the viewpoint of sufficiently reducing the cost, it is preferably 20 μm or less.

The thickness of the base metal layer 132C on the third circuit board side is preferably 0.03 μm or more from the viewpoint of preventing oxidation of the base metal layer on the other circuit board side. The upper limit of the thickness of the base metal layer 132C on the third circuit board side is also not particularly limited, but from the viewpoint of sufficiently reducing the cost, it is preferably 2.0 μm or less, and more preferably 0.5 μm or less.

According to the optical package of the present embodiment described above, since the metal layer has a specific shape, when the base material of the inorganic material used as the cover is bonded to the circuit board equipped with the optical element using the metal layer, the cover can be suppressed from cracking . [Manufacturing method of optical package] Next, a configuration example of an optical package manufacturing method of this embodiment will be described. Furthermore, the optical package described above can be manufactured by the manufacturing method of the optical package of this embodiment. Therefore, a part of the description of the items that have been explained is omitted.

The manufacturing method of the optical package of this embodiment is not particularly limited, and can be manufactured by any method or order. In the case of manufacturing an optical package, generally, a substrate 11 having an inorganic material and a window material including a substrate-side base metal layer 1311 and a substrate-side metal layer 131 including a solder layer 1312 are fabricated, and the window material is bonded to a circuit board 12. Therefore, in the manufacturing method of the optical package of the present embodiment, the case of manufacturing in the same order will be described as an example.

The manufacturing method of the optical package of this embodiment may have the following processes, for example.

The process of making window materials.

A circuit board preparation process for preparing a circuit board with optical elements.

The bonding process of disposing the window material on the circuit substrate and bonding the window material with the circuit substrate.

Hereinafter, each process will be described.

In the manufacturing process of the window material, a window material having a metal layer on the side of the substrate on one side of the substrate of the inorganic material can be produced.

Therefore, it may firstly have a substrate preparation step, which is to prepare the substrate of the inorganic material to be supplied to the window material manufacturing process.

The specific operation of the base preparation step is not particularly limited. For example, the base of the inorganic material may be cut to a desired size, or the base may be processed to have a desired shape. Furthermore, in the case where an anti-reflection film is arranged on the surface of the base of the inorganic material, an anti-reflection film can also be formed in this step. The film forming method of the anti-reflective film is not particularly limited. For example, the film can be formed by a dry method or a wet method. In the case of the dry method, a method selected from the group consisting of evaporation method, sputtering method, and ion plating can be used. The film formation is performed by one or more methods such as the method. In the case of a wet method, one or more methods selected from a dipping method, a spray coating method, etc. may be used to form a film.

Next, there may be a base-side base metal layer forming step of forming a base-side base metal layer on one surface of the base of the inorganic material, and a solder layer forming step of forming a solder layer on the base-side base metal layer.

In the step of forming the base metal layer on the base side, the base metal layer on the base side may be formed on one surface of the base of the inorganic material. The method of forming the base metal layer on the base side is not particularly limited, and can be arbitrarily selected according to the type of the base metal layer on the base side to be formed. For example, film formation can be performed by a dry method or a wet method, and in the case of a dry method, one or more methods selected from a vapor deposition method, a sputtering method, an ion plating method, etc. can be used to form a film . In the case of the wet method, one or more methods selected from the group consisting of electrolytic plating method, electroless plating method, and printing method can be used for film formation.

Furthermore, as already described, the base metal layer on the substrate side may also include a plurality of layers, and any method may be used to form a film for each layer.

In the solder layer forming step, a solder layer may be formed on one side of the base of the inorganic material or on the base metal layer on the base side. The method of forming the solder layer is not particularly limited, and examples thereof include one or more selected from the group consisting of a dipping method, a coating method using a dispenser, a printing method, a laser metal deposition method, and a method using solder wire.

The dipping method is a method of melting the solder, which is the raw material of the solder layer, in the solder melting tank, and forming the solder layer forming member, for example, the base material of the inorganic material provided with the base metal layer on the substrate side, for forming the solder layer Part of the molten solder immersed in the solder melting tank to form a solder layer.

The coating method using a dispenser is a method of supplying a part for forming a solder layer from a dispenser for example a syringe connected to a member for forming a solder layer, for example, an inorganic material provided with a base metal layer on a substrate side The molten solder forms a solder layer.

The printing method is a method in which a solder layer is formed by printing a solder in a paste form on a portion of a member for forming a solder layer, for example, an inorganic material substrate provided with a base-side metal layer on the substrate side for forming a solder layer. Furthermore, heat treatment may be performed after printing as required.

The laser metal deposition method is a method of supplying powdered solder to a portion of a member for forming a solder layer, for example, an inorganic material substrate provided with a base-side metal layer on the substrate side for forming a solder layer, using a laser After the solder melts, it is cooled to form a solder layer.

The method of using a solder wire is a method of using a solder processed into a wire shape, that is, a linear shape, for example, using an automatic soldering robot, etc., for a member for forming a solder layer, such as an inorganic material provided with a base metal layer on the base side The portion of the base for forming the solder layer supplies molten solder to form the solder layer.

The window material manufacturing process can also have any steps as needed.

The base metal layer or the solder layer on the base side can be formed on the surface 11a of the base 11 of the inorganic material so as to have a desired shape as explained using FIGS. 1(A) and 1(B).

Therefore, the manufacturing process of the window material can also be achieved after forming the base-side base metal layer and the solder layer by, for example, the base-side base metal layer forming step and the solder layer forming step. The patterning step of patterning is carried out in the form of shape. In the patterning step, for example, a resist corresponding to the pattern to be formed may be disposed on the exposed surface of the solder layer, and the portions of the base metal layer on the substrate side and the solder layer that are not covered by the resist are removed by etching or the like And patterned. The resist removing step of removing the resist may also be performed after the patterning step.

Furthermore, when the base metal layer on the base side includes a plurality of layers, a patterning step may be performed after forming a part of the layer included in the base metal layer on the base side to form the film Part of the layers contained in is patterned. Furthermore, after the patterning step, a resist removing step for removing the resist may be performed, and then the remaining base-side base metal layer may be formed on the patterned base-side base metal layer.

In addition, the manufacturing process of the window material may have a resist disposition step of disposing a resist on the portion where the base side base metal layer and the solder layer are not formed before the base side base metal layer forming step and the solder layer forming step . By forming the base-side base metal layer and the solder layer after forming the resist, the base-side base metal layer and the solder layer can be formed only in the portion corresponding to the pattern to be formed. In this case, a resist removal step of removing the resist may be provided after the solder layer forming step.

In addition, a plurality of bonding layers corresponding to each window material, that is, a substrate-side metal layer, are formed on the substrate (material before cutting) of an inorganic material of a size corresponding to the plurality of window materials in a manner capable of simultaneously manufacturing a plurality of window materials In this case, a cutting step for cutting the base of the inorganic material may also be provided. The cutting method is not particularly limited, and a cutting method corresponding to the base of the inorganic material, such as the already described cutting method using laser light, can be used. In addition, in the case where the base metal layer on the base side is continuously formed on adjacent window materials, that is, when the base metal layer on the base side is arranged on the cutting line, it can also be used in the cutting step. The base metal layer on the base side is cut together.

In addition, after the optical package is made, the base of the inorganic material and the like can also be cut together with the circuit board to be singulated.

Next, the circuit board preparation process will be described.

During the preparation of the circuit board, optical elements can be arranged on the conventionally manufactured circuit board, and a circuit board with optical elements can be prepared. The base metal layer on the side of the circuit board described above may also be provided on the circuit board.

The method of forming the base metal layer 132 on the circuit board side is not particularly limited, and for example, it can be arbitrarily selected according to the type of the base metal layer 132 on the circuit board side to be formed. For example, film formation can be performed by a dry method or a wet method, and in the case of a dry method, one or more methods selected from a vapor deposition method, a sputtering method, an ion plating method, etc. can be used to form a film . In the case of the wet method, one or more methods selected from the group consisting of electrolytic plating method, electroless plating method, and printing method can be used for film formation.

As already mentioned, the base metal layer on the circuit substrate side may also include a plurality of layers, and any method may be used to form a film for each layer.

Since the base metal layer 132 on the circuit board side constitutes the metal layer 13, it may be etched in advance in such a manner that its cross-sectional shape becomes a specific shape described with reference to FIG.

In the case where the circuit board and the like are singulated after the bonding process is completed, a circuit board before cutting in which a plurality of circuit boards are integrated can be prepared during the circuit board preparation process.

Then, during the bonding process, a window material may be arranged on the circuit substrate, and the window material and the circuit substrate may be bonded. The specific method of bonding is not particularly limited. For example, the lower surface of the solder layer 1312 of the window material and the exposed upper surface of the base metal layer 132 on the circuit board side can be overlapped in direct contact. Then, for example, at least a part of the solder layer 1312 may be melted by pressing one surface from the other surface 11b of the inorganic material base 11 of the window material toward the circuit board 12 side to heat, and then cooling, thereby cooling the window Material is joined to the circuit board 12.

In addition, the method of pressing the base 11 of the inorganic material is not particularly limited. For example, a method of using a pressing mechanism having an elastic body such as a pressing member in contact with the base 11 of the inorganic material and a spring that applies pressure to the pressing member, Or use the hammer method.

In the optical package obtained after the bonding process, when a specific atmosphere is set in the area sealed by the base 11 of the inorganic material and the metal layer 13 and the circuit board 12, it is preferable to set the atmosphere during heat treatment in advance For that particular atmosphere. For example, it may be an atmosphere selected from an atmospheric atmosphere, a vacuum atmosphere, an inert atmosphere, and the like. As the inert atmosphere, an atmosphere containing one or more kinds of gases selected from nitrogen, helium, and argon can be used.

In the joining process, the conditions for performing the heat treatment are not particularly limited, and for example, it is preferably heated to the melting temperature of the solder of the solder layer or higher. However, if heating is carried out quickly, there may be a case where thermal stress is generated in the matrix of the inorganic material, causing cracks, etc. Therefore, for example, it is preferable to first raise the temperature to 50° C. or more and not reach the melting point of the solder layer of the first heat treatment temperature , And then kept at the first heat treatment temperature for a fixed time. The holding time at the first heat treatment temperature is not particularly limited. For example, it is preferably 30 seconds or more, and more preferably 60 seconds or more. However, from the viewpoint of productivity, the holding time at the first heat treatment temperature is preferably 600 seconds or less.

Preferably, after holding at the first heat treatment temperature for a fixed time, the temperature is further increased to a temperature above the melting point of the solder of the solder layer, that is, the second heat treatment temperature. In addition, in order to sufficiently join the window material and the circuit board, the second heat treatment temperature is preferably the melting point of the solder + 20° C. or more, and in the case where the second heat treatment temperature is excessively high, there are optical elements arranged on the circuit board In the case of damage due to heat, the second heat treatment temperature is preferably, for example, 300° C. or lower. The holding time at the second heat treatment temperature is not particularly limited, but in order to sufficiently join the window material and the circuit board, it is preferably 20 seconds or more. However, in order to more reliably suppress the adverse effects of heat on the optical element, the time for maintaining the temperature at the second heat treatment is preferably 1 minute or less.

After the heat treatment at the second heat treatment temperature, it can be cooled to room temperature, for example 23°C, and the joining process is ended.

The manufacturing method of the optical package of this embodiment may have any process as required. For example, when a plurality of circuit boards that are integrated into a single undivided circuit board are provided to the bonding process, a cutting process may also be provided. The cutting method used in the cutting process is not particularly limited, and can be cut by any method. The circuit board and the base material of the inorganic material can also be cut at the same time by using the cutting method using laser light that has been described, to make it into a single piece. Also, a plurality of cutting methods may be combined. [Example]

Hereinafter, the present invention will be specifically described by way of examples and comparative examples, but the present invention is not limited to these examples, and the embodiment can be appropriately changed within the scope of exerting the effects of the present invention.

First, the evaluation method of the optical packages produced in the following examples and comparative examples will be described. <Evaluation method> [Fracture assessment] For the optical packages produced in the following examples and comparative examples, an optical microscope (SMZ900 manufactured by Nikon) was used to perform magnified observation of the interface between the inorganic material substrate and the metal layer through the inorganic material substrate at a magnification of 10 times to confirm The state of the matrix of the inorganic material, and the fracture is evaluated under the following conditions.

〇: There is no crack or crack in the contact part of the base of the inorganic material and the metal layer.

×: There is cracking or cracking on the contact surface of the inorganic material substrate with the metal layer.

Set 〇 to pass. [Air tightness] For the optical packages produced in the following examples and comparative examples, a helium leak test was conducted under the conditions described in JIS Z 2331 (2006), and the airtightness was evaluated under the following conditions.

○: The helium leak rate is 4.9 × 10 ^-9 Pa·m ³ /sec or less ×: The helium leak rate is greater than 4.9 × 10 ^-9 Pa·m ³ /sec. [Example 1] The base metal layer on the circuit board side further has a Ni-Cr layer. In addition to this aspect, an optical package having the structure shown in FIGS. 1(A) and 1(B) was fabricated, and the above-mentioned crack evaluation was performed, and Evaluation of air tightness. (Window material manufacturing process) Prepare a quartz plate (manufactured by AGC, AQ, 3.4 mm in length×3.4 mm in width×0.5 mm in thickness, thermal expansion coefficient of 0.6 ppm) as the substrate 11 of the inorganic material (substrate preparation step).

The base-side base metal layer 1311 is formed on the one surface 11a of the base 11 of the inorganic material in the following order (base-side base metal layer forming step).

As the first base-side base metal layer 1311A, a chromium (Cr) layer is formed, and as the second base-side base metal layer 1311B, a copper (Cu) layer is formed.

Next, apply a resist to the entire surface of the second base metal layer 1311B opposite to the surface of the first base metal layer 1311A, that is, the exposed surface, and then use ultraviolet light to make The resist is exposed to light, and then developed, thereby disposing the patterned resist (resist disposition step). The patterned resist has a quadrangular shape in a cross section parallel to a surface 11a of the base 11 of the inorganic material, and has a shape with a quadrangular opening in the center.

Then, portions of the first base-side base metal layer 1311A and the second base-side base metal layer that are not covered by the resist are etched with an etching solution to perform patterning (patterning step). Thereafter, the resist is removed (resist removal step).

Next, on the patterned first base-side base metal layer 1311A and the second base-side base metal layer 1311B, a nickel (Ni) layer is formed as a third base-side base metal layer 1311C by electroless nickel plating. Thereby, a patterned base-side base metal layer 1311 including the first base-side base metal layer 1311A, the second base-side base metal layer 1311B, and the third base-side base metal layer 1311C is formed.

Next, a solder layer 1312 is formed on the base-side base metal layer 1311 (solder layer forming step). The solder used for the solder layer 1312 is manufactured in advance in the following order.

The components contained in the solder were weighed and mixed so that Sn became 97.499% by mass, Ge became 1.5% by mass, Ni became 1.0% by mass, and Ir became 0.001% by mass, and melted to temporarily make a raw material alloy. Then, after melting the raw material alloy, it flows into a mold to produce solder.

With respect to the obtained solder, the Young's modulus was calculated from the tensile test results, and the result was confirmed to be 20 GPa. Regarding the tensile test, a tensile tester (Autograph AGX-100kN manufactured by Shimadzu Corporation) was used to test the JIS14A test piece at a tensile speed of 3 mm/min.

The above-mentioned solder which becomes the raw material of the solder layer 1312 is melted in advance in the solder-melting bath, and the portion of the base 11 provided with the inorganic material of the base-side base metal layer 1311 for forming the solder layer 1312 is immersed and melted in the solder-melting bath In the solder, cooling is performed thereafter, thereby forming a solder layer 1312 (solder layer forming step). As shown in FIG. 1(A), the solder layer 1312 is formed on the surface of the third base-side base metal layer 1311C opposite to the surface facing the second base-side base metal layer 1311B. The thickness of the solder layer 1312 is set to 16 μm. (Circuit board preparation process) Furthermore, an aluminum nitride (AlN) substrate (manufactured by KYOCERA Corporation, KD-LB7248, vertical 3.45 mm×horizontal 3.45 mm×thickness 0.8 mm, thermal expansion coefficient 4.6 ppm) was prepared as the insulating substrate 121 of the circuit board 12. As described above, the insulating material of the circuit board is aluminum nitride. The insulating base material 121 has a quadrangular opening at the center of the upper surface, and has a recess 121A that is a non-through hole including the opening. The optical element 122 can be disposed in the concave portion 121A, but the optical element is not required in the evaluation of this embodiment, so the optical element is not provided and the package is fabricated. However, it has been confirmed that the evaluation results are the same even when optical elements such as light-emitting diodes are arranged.

Furthermore, the circuit board 12 has a circuit board-side base metal layer 132 on the upper surface 1211 of the insulating base 121 so as to surround the opening of the recess 121A and along the outer periphery of the upper surface 1211 of the insulating base 121 .

As the circuit board side base metal layer 132, it is assumed that the Ni-Cr layer, the first circuit board side base metal layer 132A, the second circuit board side base metal layer 132B, and the third circuit board side are formed from the insulating base material 121 side The base metal layer 132C is sequentially stacked in a layer structure.

As the first circuit board side base metal layer 132A, a copper (Cu) layer with a thickness of 1.0 μm is formed, as the second circuit board side base metal layer 132B, with a 2 μm thickness nickel (Ni) layer as a third circuit On the substrate side base metal layer 132C, a gold (Au) layer with a thickness of 0.3 μm is formed. In addition, in order to improve the adhesion between the first circuit board side base metal layer 132A and the insulating base 121, a thickness of between the insulating base 121 and the first circuit board side base metal layer 132A as described above is provided Ni-Cr layer of 0.2 μm.

The base metal layer 132 on the circuit board side has a shape corresponding to the base metal layer 131 provided on the base 11 of the inorganic material. Specifically, the cross-sectional shape of the surface perpendicular to the stacking direction (upper and lower directions in FIG. 3) of the base-side metal layer 131 provided on the base 11 of the inorganic material and the circuit-board-side base metal layer 132 is formed on the base-side metal The layer 131 has the same shape as the base metal layer 132 on the circuit board side. (Joining process) The circuit board 12 is overlapped with the window material in such a manner that the lower surface of the solder layer 1312 provided on the base metal layer 131 of the base 11 of the inorganic material directly contacts the upper surface of the base metal layer 132 on the circuit board side. Then, a hammer is placed on the other surface 11b of the base 11 of the inorganic material, and while pressing, at least a part of the solder layer 1312 is melted and then cooled.

Through the above process, the window material and the circuit board 12 are bonded to produce an optical package.

In addition, based on the results of preliminary tests conducted in advance, the pattern when the base metal layer is formed on the substrate side and the pressing force during the bonding process are adjusted so that L1 to L4 shown in Table 1 become a specific value Make adjustments.

The obtained bonded body, that is, the optical package, was evaluated as described above. The results are shown in Table 1. [Examples 2 to 4 and Comparative Examples 1 to 3] Based on the results of preliminary tests performed in advance, the pattern when the base metal layer on the base side is formed and the pressing force during bonding are adjusted to thereby The adjustment is performed such that L1 to L4 shown in Table 1 become the specific values shown in Table 1. In addition, in Example 4, the material of the insulating substrate 121 of the circuit board 12, that is, the insulating material of the circuit board is alumina (Al ₂ O ₃ ). In addition, when the base-side metal layer 131 is formed, the thickness of the solder layer 1312 is set to 16 μm in Examples 2, 3 and Comparative Examples 2 and 3, and the solder layer 1312 is used in Example 4 and Comparative Example 1. The thickness is set to 26 μm.

Except for the above, the experiment was carried out in the same manner as in Example 1. The evaluation results are shown in Table 1.

根據表1所示之結果，可確認於金屬層之形狀滿足L1＜L2＜L3＜L4之實施例1～實施例4中，破裂評估、及氣密性之評估之結果為〇。即，可確認成為抑制了於罩蓋產生破裂之光學封裝。[Table 1]

From the results shown in Table 1, it can be confirmed that in Examples 1 to 4 in which the shape of the metal layer satisfies L1<L2<L3<L4, the results of fracture evaluation and airtightness evaluation are 0. That is, it can be confirmed that the optical package is suppressed from cracking in the cover.

On the other hand, in Comparative Examples 1 to 3 in which the shape of the metal layer did not satisfy L1<L2<L3<L4, it was also confirmed that cracks occurred and the airtightness was insufficient.

The optical package has been described above with the embodiments and examples, but the present invention is not limited to the above-mentioned embodiments and examples. Various changes and modifications can be made within the scope of the gist of the invention described in the scope of patent application.

This application claims the priority based on Japanese Patent Application No. 2018-141777 filed with the Japanese Patent Office on July 27, 2018, and incorporates the entire contents of Japanese Patent Application No. 2018-141777 into this international application.

10‧‧‧Optical packaging 11‧‧‧Matrix of inorganic materials 11a‧‧‧One side 11b‧‧‧The other side 12‧‧‧ circuit board 13‧‧‧Metal layer 13A‧‧‧point 13B‧‧‧point 13C‧‧‧point 13D‧‧‧point 111‧‧‧Linear pattern 121‧‧‧Insulating base material 121A‧‧‧Recess 121B‧‧‧Wall 122‧‧‧Optics 131‧‧‧Metal side metal layer 132‧‧‧ Base metal layer on the side of the circuit board 132A‧‧‧First base metal layer on the circuit board side 132B‧‧‧Second base metal layer on the second circuit board side 132C‧‧‧The third base metal layer on the circuit board side 1211‧‧‧Upper surface 1212‧‧‧End 1311‧‧‧Substrate base metal layer 1311A‧‧‧First base metal layer 1311B‧‧‧Second base metal layer 1311C‧‧‧The third base metal layer 1312‧‧‧Solder layer L1‧‧‧Distance L2‧‧‧Distance L3‧‧‧Distance L4‧‧‧Distance

1(A) and (B) are explanatory diagrams of the configuration of the optical package of this embodiment. FIG. 2 is an explanatory diagram of a configuration example of a side surface of a base body of an inorganic material. FIG. 3 is a cross-sectional view of the plane parallel to the thickness direction of the periphery of the junction between the cover of the optical package and the base of the inorganic material of this embodiment.

10‧‧‧Optical packaging

11‧‧‧Matrix of inorganic materials

11a‧‧‧One side

11b‧‧‧The other side

12‧‧‧ circuit board

13‧‧‧Metal layer

121‧‧‧Insulating base material

121A‧‧‧Recess

121B‧‧‧Wall

122‧‧‧Optics

131‧‧‧Metal side metal layer

132‧‧‧ Base metal layer on the side of the circuit board

132A‧‧‧First base metal layer on the circuit board side

132B‧‧‧Second base metal layer on the second circuit board side

132C‧‧‧The third base metal layer on the circuit board side

1211‧‧‧Upper surface

1311‧‧‧Substrate base metal layer

1311A‧‧‧First base metal layer

1311B‧‧‧Second base metal layer

1311C‧‧‧The third base metal layer

1312‧‧‧Solder layer

Claims (5)

An optical package with: A circuit board having a concave portion on the upper surface and an optical element in the concave portion; A base body of an inorganic material, which is arranged on the circuit board so as to cover the opening of the recess; and A metal layer that joins the base of the inorganic material to the circuit board; and In a cross section parallel to the stacking direction of the circuit board and the base of the inorganic material and passing through the recess, The distance between the end of the outer peripheral side of the circuit board and the end of the outer peripheral side of the circuit board in the portion where the metal layer and the circuit board are in contact is L1. The distance between the end of the outer peripheral side of the circuit board and the metal layer and the base of the inorganic material is L2, the distance between the ends of the outer peripheral side of the circuit board The distance between the end of the circuit board on the outer peripheral side and the end of the metal layer and the base of the inorganic material on the side of the recess is L3, and L4 is the distance between the end portion of the outer peripheral side of the circuit board and the end portion located on the concave portion side of the portion where the metal layer and the circuit board are in contact The relationship of L1<L2<L3<L4 is satisfied. The optical package according to claim 1, wherein the above L1 and the above L2 are in the range of 0.05 mm≦L1≦0.15 mm, 0.15 mm≦L2≦0.50 mm, respectively. According to the optical package of claim 1 or 2, wherein the above-mentioned L3 and the above-mentioned L4 are respectively in the range of 0.40 mm≦L3≦0.55 mm, 0.45 mm≦L4≦1.00 mm. The optical package according to any one of claims 1 to 3, wherein the metal layer has a base metal layer and a solder layer, and The thickness of the above solder layer is 5 μm or more. The optical package according to claim 4, wherein the Young's modulus of the solder used for the above solder layer is 50 GPa or less.

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