TWI784013B - Window materials, optical packaging - Google Patents

Abstract

The present invention provides a window material, which is used for optical packaging of optical elements, and has: a base of inorganic materials; and a bonding layer, which is arranged on one surface of the base of inorganic materials; The volume ratio is 10% or less.

Description

Window materials, optical packaging

The invention relates to a window material and an optical package.

Conventionally, after arranging optical elements such as light-emitting diodes in a recessed portion of a circuit board, the opening of the recessed portion is sealed with a window material including a transparent resin base material, and used as an optical package.

In this case, the window material is bonded to the circuit board with a resin adhesive or the like, but improvement in airtightness is required depending on the type of optical element or the like. For this reason, conventionally, studies have been made on bonding a circuit board and a window material using a metal material instead of a resin-made adhesive.

For example, Patent Document 1 discloses a light-emitting device characterized by comprising: a mounting substrate; an ultraviolet light emitting element mounted on the mounting substrate; a spacer arranged on the mounting substrate and formed with a A through hole through which the light-emitting element is exposed; and a cover disposed on the spacer so as to close the through hole of the spacer; and the spacer includes: a spacer body containing Si; and a second bonding metal a layer formed along the entire circumference of the outer periphery of the facing surface on the side of the spacer main body facing the mounting substrate, facing the first metal layer for bonding of the mounting substrate; and The through hole is formed in the spacer body, and the opening area of the through hole gradually increases as the distance from the mounting substrate increases. The cover includes glass that transmits ultraviolet rays emitted from the ultraviolet light emitting element. The spacer and the cover cover In direct bonding, the second metal layer for bonding of the spacer and the first metal layer for bonding of the mounting substrate are bonded by AuSn over the entire circumference of the second metal layer for bonding. [Prior Art Document] [Patent Document]

Patent Document 1: Japanese Patent No. 5877487

[Problem to be solved by the invention]

However, the cover used in the light-emitting device disclosed in Patent Document 1 is bonded to the mounting substrate using AuSn through the spacer, and since the amount of gold (Au) used is large, there is a problem in terms of cost. question.

In view of the above-mentioned problems of the prior art, an aspect of the present invention aims to provide a window material with reduced cost. [Technical means to solve the problem]

In order to solve the above-mentioned problems, in one aspect of the present invention, a window material is provided, which is a window material for optical packaging with optical elements, and has: a substrate of an inorganic material; and a bonding layer, which is arranged on the above-mentioned inorganic material and the volume ratio of gold in the bonding layer is 10% or less. [Effect of Invention]

According to one aspect of the present invention, it is possible to provide a window material with reduced cost.

Hereinafter, embodiments for implementing the present invention will be described with reference to the drawings. The present invention is not limited to the following embodiments, and various changes and substitutions can be made to the following embodiments without departing from the scope of the present invention. [Window Material] An example of the configuration of the window material of this embodiment will be described.

The window material of this embodiment relates to a window material for optical packaging with an optical element, has a substrate of an inorganic material, and a bonding layer disposed on one surface of the substrate of the inorganic material, and the volume ratio of gold in the bonding layer is Below 10%.

The structural example of the window material of this embodiment is demonstrated concretely below using FIG. 1(A) and FIG. 1(B). FIG. 1(A) schematically shows a cross-sectional view obtained by using a plane parallel to the lamination direction of the substrate 11 of the inorganic material and the bonding layer 12 of the window material 10 of this embodiment. Moreover, FIG. 1(B) shows the structure of the window material 10 shown in FIG. 1(A) viewed along block arrow (block arrow) A shown in FIG. 1(A). That is, a bottom view of the window material 10 shown in FIG. 1(A) is shown.

The window material 10 of this embodiment has a base 11 and a bonding layer 12 of inorganic materials. Furthermore, the bonding layer 12 can be arranged on the one surface 11a of the substrate 11 of the inorganic material.

Here, the surface 11a of the substrate 11 of the inorganic material corresponds to the surface on the side that is bonded to the circuit board provided with the optical element when the optical package is manufactured. That is, the surface 11a of the substrate 11 of the inorganic material may also be referred to as a surface on the side facing the optical element.

Furthermore, the other surface 11b of the substrate 11 of the inorganic material, which is located on the opposite side to the one surface 11a, becomes a surface exposed to the outside when it is formed into an optical package.

In addition, although the case where the base body 11 of an inorganic material is plate-shaped is shown in FIG. 1 as an example, it is not limited to this shape.

Here, each member included in the window material of this embodiment is demonstrated. (Substrate of Inorganic Material) The substrate 11 of inorganic material is not particularly limited, and any material can be used and any shape can be used.

However, when the substrate 11 of an inorganic material is made into an optical package, it is preferable to use the light in the wavelength region that is particularly required to be transmitted among the light related to the optical elements of the circuit board (hereinafter described as "desired"). The light in the wavelength region"), the way the transmittance becomes sufficiently high, the choice of material, or its thickness, etc. For example, the transmittance of light in a desired wavelength region is preferably at least 50%, more preferably at least 70%, further preferably at least 80%, and most preferably at least 90%.

When the light in the desired wavelength region of the substrate 11 of the inorganic material is light in the infrared region, for example, the transmittance is preferably 50% or more, more preferably 70% or more, more preferably 80% or more, especially preferably 90% or more.

In addition, when the light in the desired wavelength region of the substrate 11 of the inorganic material is light in the visible region (blue-green-red), for example, the transmittance is relatively high for light in the wavelength range of 380 nm to 800 nm. Preferably it is 50% or more, more preferably 70% or more, still more preferably 80% or more, especially preferably 90% or more.

When the light in the desired wavelength region of the substrate 11 of the inorganic material is light in the ultraviolet region, for example, the transmittance is preferably 50% or more, more preferably 70% or more, more preferably 80% or more, especially preferably 90% or more.

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

When the light in the desired wavelength region of the substrate 11 of the inorganic material is UV-B light in the ultraviolet region, for example, the transmittance is preferably 50% or more for light having a wavelength of 280 nm or more and 315 nm or less. , more preferably 70% or more, further preferably 80% or more, especially preferably 90% or more.

When the light in the desired wavelength region of the substrate 11 of the inorganic material is UV-C light in the ultraviolet region, for example, the transmittance is preferably 50% or more for light in the wavelength range of 200 nm or more and 280 nm or less , more preferably 70% or more, further preferably 80% or more, especially preferably 90% or more.

In addition, the transmittance of the base body 11 of an inorganic material can be measured based on JISK 7361-1 (1997).

The material of the substrate 11 of the inorganic material can be arbitrarily selected as described above, and is not particularly limited, but from the standpoint of particularly improving airtightness or durability, for example, quartz, or glass etc. Quartz includes quartz glass, or one containing 90% by mass or more of SiO ₂ . Examples of 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 matrix of an inorganic material is not limited to 1 type, You may use combining 2 or more types of materials. Therefore, for example, as the material of the substrate 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 of glass (nd≧1.5).

In the case of using glass as the material of the inorganic material base 11, the inorganic material base 11 may also be chemically strengthened.

There is no particular limitation on the thickness of the substrate 11 of the inorganic material. For example, it is preferably set at 0.03 mm or more, more preferably at least 0.05 mm, still more preferably at least 0.1 mm, and most preferably at least 0.3 mm. mm or more.

By setting the thickness of the inorganic material base 11 to 0.03 mm or more, it is possible to fully exert the strength required for the optical package, and at the same time, it is possible to especially suppress the penetration of moisture, etc., through the surface of the inorganic material base 11 of the window material to the optical element disposed thereon. side. By setting the thickness of the substrate 11 of the inorganic material to 0.3 mm or more as described above, the strength can be improved especially for optical packaging, which is preferable.

There is no particular limitation on the upper limit of the thickness of the substrate 11 of the inorganic material. For example, it is preferably set to 5 mm or less, more preferably 3 mm or less, and still more preferably 1 mm or less. This is because the transmittance of light in a desired wavelength region can be sufficiently increased by setting the thickness of the substrate 11 of the inorganic material to 5 mm or less. By setting the thickness of the substrate 11 of the inorganic material to 1 mm or less, it is possible to achieve a reduction in the height of the optical package, which is further preferred.

Furthermore, the shape of the inorganic material matrix 11 is not particularly limited, and the thickness does not need to be uniform. Therefore, when the thickness of the substrate of the inorganic material is not uniform, it is preferable that the thickness of at least the part of the substrate of the inorganic material on the optical path of the light related to the optical element in the case of making an optical package is within the above-mentioned thickness. range, more preferably the thickness of the substrate of the inorganic material is within the above range at any part.

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

Furthermore, even when the surface 11a of the substrate 11 of the inorganic material has protrusions or recesses, the part where the bonding layer 12 is arranged on the surface 11a of the substrate 11 of the inorganic material is also for example in the case of manufacturing a plurality of window materials 10. etc. It is preferable that the shape of the bonding layer 12 between the window materials 10 is flat while suppressing variation in shape.

The side surface of the substrate 11 of inorganic material may have a linear pattern along the outer periphery of one surface 11a.

The window material of this embodiment can be arranged, for example, on a circuit board on which an optical element is arranged to form an optical package. Therefore, depending on the form of the optical package, the size of the window material may become extremely small. Therefore, when cutting the pre-cut material of the inorganic material base 11 into a desired size, it is preferable to use a cutting method using laser light.

For example, in the cutting method using laser light, first, the focus position of the laser light is set to be an arbitrary position in the thickness direction of the material before cutting the substrate of the inorganic material, so that the irradiation position of the laser light is along the cutting line. , and move the irradiation position of the laser light and/or the material before the cutting of the matrix of the inorganic material. Thereafter, by applying a force such that the cutting line becomes a fulcrum, or by applying the force naturally, the pre-cutting material of the inorganic material matrix can be cut into an arbitrary shape along the cutting line.

In the above-mentioned cutting method, it can be considered that by setting the focus position of the laser light at an arbitrary position in the thickness direction of the material before cutting the substrate of the inorganic material, and moving the irradiation position of the laser light, etc., the inorganic material The bonding state of the inorganic material changes in the part where the focus position of the laser light of the material before cutting the substrate passes. Therefore, it is presumed that, by applying a force thereafter, the pre-cutting material of the inorganic material matrix can be easily cut starting from the portion where the bonded state of the inorganic material changes.

Furthermore, it is also possible to change the focal position of the laser light in the thickness direction of the inorganic material base before cutting according to the thickness of the material before cutting the base of the inorganic material, and to irradiate the laser light multiple times along the cutting line. In this way, when changing the focus position of the laser light and irradiating the laser light several times along the cutting line, it is preferable to irradiate the laser light each time, so that the laser light is irradiated in the direction of the thickness of the material before cutting the substrate of the inorganic material. The focal point position changes from a position farther away from the incident surface of the laser light to a closer position.

In terms of suppressing the occurrence of defects such as defects, cracks, and chipping on the cut surface, the number of irradiations with laser light is preferably 2 or more, more preferably 3 or more, and still more preferably 5 or more . The upper limit of the number of times of laser light irradiation is not particularly limited, but if it exceeds 10 times, the cost will increase, so it is preferably 10 times or less.

In addition, when cutting is performed by this cutting method, it is considered that a linear pattern due to a change in the bonding state of the inorganic material remains at the position where the focal position of the laser light passes. Since the focus position of the laser light is set to be an arbitrary position in the thickness direction of the material before cutting the substrate of the inorganic material, it can be set along one side of the substrate 11 of the inorganic material, for example, as shown in FIG. 2 11a or the linear pattern 111 on the outer periphery of the other surface 11b. From the viewpoint of suppressing the occurrence of defects, cracks, and chipping during cutting, the linear pattern 111 is preferably a linear pattern parallel to one side 11a or the other side 11b of the substrate 11 of the inorganic material, But it doesn't have to be parallel.

Furthermore, when laser light is irradiated multiple times along the cutting line as described above, the same number of linear patterns as the number of times of irradiation remains on the side surface of the substrate of the obtained inorganic material, that is, the cut surface. Also, from the viewpoint of suppressing the occurrence of defects such as chipping of the cut surface, it is preferable that the intervals between the plurality of linear patterns formed are substantially the same. Specifically, for example, the width between the linear patterns contained in the side surface of the substrate of the inorganic material obtained after cutting is preferably controlled within 20% of the central value. Since the linear pattern is generated at a position corresponding to the focal position of the laser light, the interval between the linear patterns can be controlled by using the focal position of the laser light.

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

An anti-reflection film may also be pre-disposed on the surface of the substrate 11 of inorganic materials. By disposing the anti-reflection film, in the case of making an optical package, it is possible to suppress the light from the optical element or the outside from being reflected on the surface of the substrate 11 of the inorganic material, and improve the transmittance of the light from the optical element or the outside. good. The antireflection film is not particularly limited, and for example, a multilayer film can be used. The multilayer film can be alternately laminated with a material selected from aluminum oxide (alumina, Al ₂ O ₃ ), hafnium oxide (HfO ₂ ), titanium oxide (TiO ₂ ) A film of the first layer of one or more layers of material and the second layer of a silicon dioxide (silicon oxide, SiO ₂ ) layer. The number of layers constituting the multilayer film is not particularly limited. For example, if the above-mentioned first layer and the second layer are set as one set, the multilayer film preferably has more than one set of the first layer and the second layer, more preferably For having 2 or more groups. The reason for this is that, since the multilayer film has at least one set of first and second layers, it is possible to suppress reflection of light on the surface of the substrate 11 made of an inorganic material.

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

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

When the above-mentioned multilayer film is used as an antireflection film, it is preferable that the second layer of silicon dioxide is located on the outermost surface. The reason for this is that since the second layer of silicon dioxide is located on the outermost surface of the antireflection film, the surface of the antireflection film has a composition similar to that of the surface of the glass substrate, and the durability and adhesion to the bonding layer 12 are especially Higher, better. (Joining layer) The joining layer 12 corresponds to a member for joining the substrate 11 of an inorganic material and the circuit board provided with an optical element when forming an optical package. Therefore, as long as the bonding layer 12 is a member capable of bonding the substrate 11 of the inorganic material and the circuit board including the optical element, its specific configuration is not particularly limited. However, from the viewpoint of improving the airtightness of the optical package, the bonding layer 12 preferably contains a metal material. Also, regarding the bonding layer 12, the volume ratio of gold in the bonding layer 12 is preferably 10% or less. By setting the volume ratio of gold in the bonding layer 12 to 10% or less, the ratio of gold contained in the bonding layer can be sufficiently suppressed, and the cost of the window material can be suppressed. The volume ratio of gold in the bonding layer 12 is more preferably 8% or less, further preferably 6% or less.

Furthermore, since the bonding layer 12 does not need to contain gold, the volume ratio of gold in the bonding layer 12 can be set to 0 or more.

The bonding layer 12 may have a substantially uniform thickness of each layer, such as a solder layer described below. Therefore, for example, in the case where the layer containing gold exists in the form of a gold layer composed of gold in the bonding layer 12, the volume ratio of gold can also be set as the ratio of the thickness of the gold layer to the thickness of the bonding layer 12. ratio. Also, when the gold-containing layer also contains components other than gold, the ratio of the thickness of the gold-containing layer to the thickness of the bonding layer 12 may be multiplied by the ratio of the gold in the gold-containing layer. The value obtained from the volume content ratio.

In addition, when calculating the volume ratio of the gold in a bonding layer using the thickness of each layer as mentioned above, the average value of simple average can be used as the thickness of the following solder layer.

The bonding layer 12 preferably has a base metal layer 121 and a solder layer 122 as shown in FIG. 1(A), for example.

The base metal layer 121 may have the function of improving the adhesion between the inorganic material base 11 and the solder layer 122 . The composition of the base metal layer 121 is not particularly limited, and preferably includes a plurality of layers as shown in FIG. 1(A) .

The composition of the base metal layer 121 is not particularly limited, for example, it may include 2 or 3 layers. Specifically, for example, the first base metal layer 121A and the second base metal layer 121B may be provided in order from the base 11 side of the inorganic material. In addition, a third base metal layer (not shown) may be further disposed between the second base metal layer 121B and the solder layer 122 .

The first base metal layer 121A may have the function of improving the adhesion between the inorganic material substrate 11 and other layers. The material of the first base metal layer 121A is preferably a material that can improve the adhesion between the inorganic material base 11 and other layers, and is more preferably a material that can also improve the airtightness. For example, the first base metal layer 121A is preferably a layer containing one or more selected from chromium (Cr), titanium (Ti), tungsten (W), and palladium (Pd). The first base metal layer 121A may be, for example, a layer containing one or more materials selected from chromium (Cr), titanium (Ti), tungsten (W), and palladium (Pd). Furthermore, in this case, it is not excluded that the first base metal layer 121A contains unavoidable impurities.

The first base metal layer 121A is more preferably a metal film or a metal oxide film made of one or more metals selected from chromium (Cr), titanium (Ti), tungsten (W), and palladium (Pd).

The second base metal layer 121B has the function of improving the adhesion between the solder layer and other layers, and is preferably set to contain one selected from nickel (Ni), copper (Cu), platinum (Pt), and silver (Ag), for example. The metal layer above. In particular, from the viewpoint of cost suppression, the second base metal layer 121B is more preferably a layer containing one or more metals selected from nickel (Ni) and copper (Cu).

Furthermore, the second base metal layer 121B may be, for example, a layer containing one or more metals selected from nickel (Ni), copper (Cu), platinum (Pt), and silver (Ag). In this case, the second base metal layer 121B is preferably a layer containing one or more metals selected from nickel (Ni) and copper (Cu) from the viewpoint of cost. Furthermore, in any of the above cases, it is not excluded that the second base metal layer 121B contains unavoidable impurities.

Moreover, when further providing a 3rd base metal layer, it is preferable to set it as a layer containing 1 or more types selected from nickel (Ni) and gold (Au), for example as a 3rd base metal layer. In particular, when the third base metal layer is a layer containing nickel (Ni), in order to improve the wettability of the solder, it is preferable to use a layer containing nickel-boron alloy (Ni-B), or A layer composed of Ni-B. By providing the third base metal layer, for example, it is possible to suppress the reaction between the base metal layer 121 and the solder layer 122 . The third base metal layer may also be a layer containing 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 metal layer 121 is not particularly limited, and can be selected arbitrarily.

For example, the thickness of the first base metal layer 121A is preferably 0.03 μm or more from the viewpoint of improving the adhesiveness with the substrate 11 of the inorganic material in particular. The upper limit of the thickness of the first base metal layer 121A is not particularly limited, but it is preferably 0.2 μm or less from the viewpoint of sufficiently reducing costs.

The thickness of the second base metal layer 121B is preferably 0.1 μm or more from the viewpoint of particularly improving the adhesiveness with the solder layer 122 . The upper limit of the thickness of the second base metal layer 121B is not particularly limited, but it is preferably 2.0 μm or less from the viewpoint of sufficiently reducing costs.

When the third base metal layer is also provided, the thickness is not particularly limited, but is preferably 0.05 μm or more, for example, from the viewpoint of suppressing the reaction between the base metal layer 121 and the solder layer 122 . The upper limit of the thickness of the third base metal layer is not particularly limited, but it is preferably 1.0 μm or less from the viewpoint of sufficiently reducing costs.

Next, the solder layer 122 will be described.

The solder layer 122 has the function of joining the substrate 11 of inorganic material and the circuit board with the optical element when manufacturing the optical package, and its composition is not particularly limited.

However, the average thickness of the solder layer 122 is preferably at least 5 μm, more preferably at least 15 μm. This is because, by setting the average thickness of the solder layer 122 to 5 μm or more, for example, even if the bonding surface of the circuit board to be bonded and the bonding layer 12 includes unevenness, the concave portion can be filled with the material of the solder layer, In particular, the airtight sealing performance is improved.

In addition, the average value here means the value of a simple average (it may also be called an arithmetic average or an addition average). Hereinafter, when simply referred to as "average", it means a simple average.

Also, there is no particular limitation on the upper limit of the average value of the thickness of the solder layer 122, but it is preferably 50 μm or less, more preferably 30 μm or less. This is because even if the average value of the thickness of the solder layer 122 exceeds 50 μm and becomes excessively thick, the effect of hermetic sealing does not change significantly.

Furthermore, the average value of the thickness of the solder layer 122 can be determined by using a laser microscope (manufactured by KEYENCE, model VK-8510) to measure the thickness of the solder layer 122 of the window material 10 at any plurality of measurement points, and obtain Calculate the average value. The number of measurement points for measuring the thickness of the solder layer 122 to calculate the average value is not particularly limited, for example, preferably 2 or more points, more preferably 4 or more points. The upper limit of the number of measurement points is not particularly limited, but it is preferably 10 points or less, more preferably 8 points or less, from the viewpoint of efficiency.

When calculating the average value of the thickness of the solder layer 122, for example, it is more preferable to measure the thickness at measurement points Z1 to Z8 shown in FIG. 3 and calculate the average value.

In addition, FIG. 3 is a figure shown in order to show the example of a measurement point, and is a figure corresponding to FIG. 1(B). 3 and FIG. 1(B) are views of the situation observed from the side of the window material 10 where the bonding layer 12 is formed, that is, the bottom view, and the bonding layer 12 including the solder layer 122 is arranged along the outer periphery of the matrix 11 of the inorganic material. the shape. Furthermore, the bonding layer 12 including the solder layer 122 may have an opening in the center, and the base 11 of the inorganic material can be seen from the opening.

As shown in FIG. 3 , when the solder layer 122 has a quadrangular opening in the center and has a quadrangular shape, it is preferably the measuring point Z1 at the center of the corners 31A~31D of the four sides 301~304. , Z3, Z5, Z7, and measuring points Z2, Z4, Z6, Z8 of the central positions of the edge portions 32A~32D, measure the thickness as the maximum height of the solder layer, and set the average value as the thickness of the solder layer 122 average value.

Moreover, the bottom surface shape of the solder layer is not limited to the form shown in FIG. 1(B) and FIG. It is also set to the corresponding shape. In this case, for example, the thickness may be measured at the corners of each side and each center position of the side, and the average value of the measured thicknesses may be used as the thickness of the solder layer. The corners and sides will be described later.

The deviation of the thickness of the solder layer 122, that is, the deviation of the thickness from the simple average value is preferably within ±20 μm, more preferably within ±10 μm.

The reason is that by setting the deviation of the thickness of the solder layer 122 within ±20 μm, it is possible to improve the airtightness between the window material and the circuit substrate on which the optical elements are disposed, and to make the optical package easier. good.

Furthermore, the deviation of the thickness of the solder layer 122 within ±20 μm means that the deviation is distributed in the range of not less than −20 μm and not more than +20 μm.

In addition, the variation of the thickness of the solder layer 122 can be calculated from the average value of the thickness of the said solder layer, and the measured value used when calculating the average value.

In addition, depending on the formation method of the solder layer 122 , there may be small but existing variations in the thicknesses of the corners and sides of the solder layer. Therefore, the weighted average can also be calculated for the thickness of the solder layer 122 and used as an evaluation index. When calculating the weighted average for the thickness of the solder layer 122, the weighted average of the thicknesses of the sides included in the solder layer can be calculated, and the weighted average (simple average) of the thicknesses of all sides can be set as the weighted average of the thickness of the solder layer 122. Weighted average of thickness.

The weighted average of the thickness of each side can measure the thickness at the center position of the corner and side included in each side, and when the measurement point is a corner, use the long side of the side to calculate the weighted average of the corner The length of the direction is weighted, and when the measurement point is a side, the length of the long-side direction of the side for which the weighted average of the side is calculated is used for weighting.

In addition, the corner part refers to the part where the sides of the solder layer overlap, and the side part refers to other parts. For example, in the case of the solder layer 122 shown in FIG. 3 , the solder layer 122 has a quadrangular opening in the center and has a quadrangular shape with four sides of sides 301 to 304 . Moreover, the solder layer 122 shown in FIG. 3 has corners 31A to 31D in which sides 301 to 304 overlap each other.

Specifically, corner portion 31A is a region surrounded by straight lines A1, A2, B1, and B2 where side 301 and side 304 overlap. The corner portion 31B is an area surrounded by straight lines A3, A4, B1, and B2 where the side 301 and the side 302 overlap. The corner portion 31C is a region surrounded by straight lines A3, A4, B3, and B4 where the side 302 and the side 303 overlap. The corner portion 31D is a region surrounded by straight lines A1, A2, B3, and B4 where the side 303 and the side 304 overlap.

Furthermore, the solder layer 122 shown in FIG. 3 has side portions 32A to 32D. Specifically, side portion 32A is an area surrounded by straight lines A2, A3, B1, and B2. Also, the side portion 32B is an area surrounded by straight lines A3, A4, B2, and B3. The side portion 32C is an area surrounded by straight lines A2, A3, B3, and B4. The side portion 32D is an area surrounded by straight lines A1, A2, B2, and B3.

When calculating the weighted average for the side 301, the thickness at the corners 31A, 31B, and the side 32A can be calculated by weighting the length of the side 301 in the longitudinal direction of each region in the following order. The thickness T _Z1 measured at the measurement point Z1 at the center position of the corner portion 31A is weighted by the length W1 of the side 301 in the longitudinal direction of the corner portion 31A. The thickness T _Z2 measured at the measurement point Z2 at the center position of the side portion 32A is weighted by the length L1 of the side 301 in the longitudinal direction of the side portion 32A. The thickness T _Z3 measured at the measurement point Z3 at the center position of the corner portion 31B is weighted by the length W2 of the side 301 in the longitudinal direction of the corner portion 31B. Then, the weighted average of the sides 301 can be calculated by dividing the total of the calculation results by the total of W1, L1, and W2 used for weighting.

Similarly, the weighted average of the solder layer can also be calculated for other sides by calculating the weighted average and calculating the average value.

In the case of the solder layer 122 shown in FIG. 4 , it can be calculated by the following formula (1). Weighted average=[(W1×T _Z1 +L1×T _Z2 +W2×T _Z3 )/(W1+L1+W2)+(W3×T _Z3 +L2×T _Z4 +W4×T _Z5 )/(W3+ L2+W4)+(W2×T _Z5 +L1×T _Z6 +W1×T _Z7 )/(W1+L1+W2)+(W4×T _Z7 +L2×T _Z8 +W3×T _Z1 )/(W3+ L2+W4)]/4···(1) Furthermore, T _Zx in the above formula (1) refers to the solder layer measured at each measurement point Zx (x is any one of 1 to 8). The thickness is described in the same manner below. As shown in FIG. 3 , L1 and L2 in the above formula (1) are the lengths of the sides of the opening provided in the center of the solder layer 122 . L1 and L2 may also be the lengths measured at arbitrary positions, but it is preferable to use an average value measured at a plurality of positions. For example, regarding L1, it is preferable to set it as the average value of the lengths of one side of the opening measured at both ends and the center of the opening, that is, for example, measured along the straight lines B2, B3, and B5. Also, L2 is similarly preferably set as the average value of the lengths of one side of the opening measured at both ends and the center of the opening, that is, for example, along straight lines A2, A3, and A5.

The line widths W1 to W4 of the solder layer 122 may also be lengths measured at arbitrary positions, but are preferably average values measured at a plurality of positions. For example, in the case of the line width W1, it is preferable to use the value measured along the straight line B5 passing through the center of the longitudinal direction of the side 304, and the values measured along the straight lines B2 and B3 passing through the two ends of the opening. The average value of the measured values at 3 points.

Depending on the formation method of the solder layer, for example, the thickness may become bilaterally symmetrical. For example, when a solder layer is formed by a dipping method and the dipping direction is known, the thickness of the solder layer becomes bilaterally symmetrical with the dipping direction as the center. For example, when dipping is performed along the straight line B5 in FIG. 3 , the thickness of the solder layer 122 becomes bilaterally symmetrical with the straight line B5 as the center. Therefore, in this case, the thickness of the solder layer 122 at the measurement points Z7, Z6, and Z5 becomes the same value as the thickness of the solder layer 122 at the measurement points Z1, Z2, and Z3 respectively. Points Z1~Z8 measure the thickness. For example, the thickness can be measured at 5 measuring points of measuring points Z1~Z4 and Z8, and set T _Z1 =T _Z7 , T _Z2 =T _Z6 , T _Z3 =T _Z5 , and calculate the weighted average of the thickness of the solder layer 122 . In addition, in the case of simple average, it is also possible to calculate the average value only from the values of the same measurement points.

The weighted average value of the solder layer is not particularly limited, but is preferably at least 4 μm, more preferably at least 13 μm. Also, the upper limit of the weighted average value of the solder layer is not particularly limited, for example, it is preferably 70 μm or less, more preferably 60 μm or less.

Also, the deviation from the weighted average value of the solder layer, that is, the difference between the thickness at each measurement point and the calculated weighted average value is preferably within ±30 μm.

Regarding the weighted average value and the deviation from the weighted average value, the reason for the preference is the same as that of the average value, so it is omitted.

Furthermore, the shape of the bottom surface of the solder layer is not limited to the shape shown in FIG. 1(B) and FIG. 3 , for example, it may have a polygonal shape other than a quadrangle, and the opening portion may also be set in a corresponding shape. In this case, it is also possible to calculate the weight of each side by measuring the thickness at the center position of the corner and side included in each side, and using the length of the long-side direction of the side to calculate the weighted average of each area for weighting. Average, and calculate the average of the weighted average of the thickness of all sides, and calculate the weighted average of the solder layer.

In addition, the window material of this embodiment can be used by joining with the circuit board provided with an optical element, and the solder layer 122 can join this circuit board and a window material.

Moreover, an oxide film usually exists on the surface of the solder layer 122, but in order to facilitate bonding with the circuit board, the oxide film present on the lower surface of the solder layer 122, that is, the surface of the side facing the circuit board, is preferably It melts into the inside of the solder layer 122 melted by heating, and is so thin that the melted solder layer 122 can contact the upper surface of the circuit board. The specific thickness of the oxide film on the surface of the solder layer is not limited, and the thickness of the oxide film is preferably less than 10 nm, more preferably less than 5 nm.

Since the oxide film is preferably less, the thickness of the oxide film can be set to 0 or more.

The solder layer 122 may contain various solders (joining compositions).

The solder used for the solder layer 122 is not particularly limited. For example, a material having a Young's modulus of 50 GPa or less is preferable, more preferably a material of 40 GPa or less, and still more preferably a material of 30 GPa or less.

The reason is that, as described above, the window material of this embodiment can be used as a member of an optical package, but after the optical package is manufactured, for example, when the optical element is turned on or off, the temperature of the solder layer may be generated. Variety. Furthermore, by setting the Young's modulus of the solder used for the solder layer to 50 GPa or less, even when the solder layer portion expands or shrinks due to temperature changes, damage to other members can be particularly suppressed, And better.

Also, the reason is that when the Young's modulus of the solder is 50 GPa or less, the stress caused by the difference in thermal expansion between the substrate 11 of the inorganic material and the circuit board equipped with the optical element can be reduced when the optical package is manufactured. It is preferable to absorb in the solder layer 122 that joins the two components.

The lower limit of the preferred range of the Young's modulus of the solder used for the solder layer 122 is not particularly limited, for example, as long as it is greater than 0, it is preferably 10 GPa or more from the viewpoint of improving hermeticity.

The Young's modulus of solder can be calculated from the tensile test of solder and the result.

Also, the melting point of the solder used for the solder layer 122 is preferably 200° C. or higher, more preferably 230° C. or higher. This is because, when the melting point of the solder is 200° C. or higher, the heat resistance at the time of making it into an optical package can be sufficiently improved. However, the melting point of the solder used for the solder layer 122 is preferably below 280°C. The reason for this is that at least a part of the solder layer 122 will be melted when heat treatment is performed during the manufacture of the optical package, but when the melting point of the solder is 280° C. or lower, the temperature of the heat treatment can be suppressed to be low. Suppresses damage to optical components, etc.

The density of the solder used for the solder layer 122 is preferably above 6.0 g/cm ³ , more preferably above 7.0 g/cm ³ . The reason for this is that the airtightness can be improved particularly by setting the density of the solder used for the solder layer 122 to 6.0 g/cm ³ or more. The upper limit of the density of the solder used for the solder layer 122 is not particularly limited, for example, it is preferably below 10 g/cm ³ .

The coefficient of thermal expansion of the solder used for the solder layer 122 is preferably 30 ppm or less, more preferably 25 ppm or less. This is because, when the coefficient of thermal expansion of the solder is 30 ppm or less, it is possible to suppress the shape change due to heat generated when the optical element is lighted, etc. when the optical package is manufactured, and damage to the optical package can be more reliably prevented. The lower limit of the thermal expansion rate of the solder used for the solder layer 122 is not particularly limited, for example, it is preferably above 0.5 ppm.

The copper corrosivity of the solder used for the solder layer 122 is preferably 15% or less, more preferably 10% or less. The reason for this is that when the copper corrosivity of the solder used for the solder layer 122 is 15% or less, the reaction with the base metal layer 121 and the like can be suppressed, which is preferable. The lower limit of the copper corrosivity of the solder used for the solder layer 122 is not particularly limited, but is preferably 0 or more. Furthermore, copper corrosivity of solder can be evaluated by copper corrosivity evaluation.

Copper corrosivity can be evaluated in the following procedure, for example.

Cut 2 copper wires with a diameter of 0.5 mm to a length of about 3 mm, and dip the surface of the 2 copper wires in RMA (Rosin Mildly activated, weakly active rosin) type flux to remove the oxide film.

The first copper wire after removing the oxide film was cleaned with ethanol, and the cross-sectional area S ₁ of the first copper wire was measured. Furthermore, the cross-sectional area of the copper wire means the cross-sectional area of the copper wire obtained by using a plane perpendicular to the longitudinal direction.

Next, the second copper wire from which the oxide film was removed was dipped in a solder tank that was filled with the solder to be evaluated and heated so that the temperature of the hot water became 400°C for 60 seconds. At this time, in order to prevent the oxide film from reproducing on the copper wire, dip it in a solder bath within 60 seconds after removing the oxide film with flux. After immersion in the solder bath, the copper wire was pulled up, the copper wire was ground from the end dipped in the solder bath, and the cross-sectional area S ₂ of the copper wire was measured at a position where the copper cross section could be confirmed.

The ratio of the reduction in cross-sectional area to the cross-sectional area S ₂ of the copper wire after dipping in the solder pot was calculated relative to the cross-sectional area S ₁ of the copper wire before dipping in the solder pot. Specifically, it can be calculated by the following formula. (Copper Corrosion)=(S ₁ -S ₂ )/S ₁ ×100 The solder that constitutes the solder layer is not particularly limited as mentioned above, for example, it preferably contains tin, germanium, and nickel, and the content of germanium is 10% by mass % or less, and the content of germanium and nickel satisfies the following formula (1).

[Ni]≦2.8×[Ge] ^0.3 ···(1) (wherein, [Ni] represents the content of nickel in terms of mass%, and [Ge] represents the content of germanium in terms of mass%). The above-mentioned solder can be easily joined to the object to be joined without removing the oxide film after the solder is placed on the member to be joined.

Hereinafter, components contained in the above-mentioned solder that can be preferably used for the solder layer will be described. (Tin) The above solder contains tin (Sn).

Tin can alleviate the difference in thermal expansion between members to be joined such as circuit boards and base metal layers and solder. Furthermore, by containing tin as the main component of solder, the melting point temperature of solder can be made into about 230 degreeC which is the melting point temperature of tin.

The aforementioned solder can contain tin as a main component. Containing as a main component means, for example, including the largest component in the solder, and preferably means including 60% by mass or more of the component in the solder.

In particular, the tin content of the solder is, for example, more preferably at least 85.9% by mass, further preferably at least 87.0% by mass, and particularly preferably at least 88.0% by mass.

The reason for this is that when the content of tin in the solder is 85.9% by mass or more, it exhibits a particularly good effect on alleviating the difference in thermal expansion between the members to be joined and the solder and reducing 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 at most 99.9% by mass, more preferably at most 99.5% by mass, further preferably at most 99.3% by mass.

The above-mentioned solder also contains germanium and nickel in addition to tin. And, by containing these components, it is possible to suppress the generation of an oxide film on the surface of the solder when it is applied to the member to be joined. In addition, the above-mentioned solder may contain any of the following components in addition to germanium and nickel. Therefore, in order to sufficiently ensure the content of the components other than tin, the content of tin is preferably 99.9% by mass or less as described above.

Furthermore, as described below, the hermeticity between members to be joined can be particularly improved by the content of germanium or the like. From the viewpoint of improving hermeticity, the content of components such as germanium other than tin in the solder is preferably at least a fixed amount. Therefore, the upper limit of the tin content is particularly preferably set to 98.8% by mass or less when particularly improving the airtightness is required. (Germanium) The above-mentioned solder contains germanium.

Germanium can suppress the formation of an oxide film on the surface of the solder when the solder is applied to the joint surfaces of the members to be joined. This is because germanium contained in the solder is preferentially oxidized when melting for coating the solder, and oxidation of nickel in the solder can be suppressed.

The content of germanium in the solder is not particularly limited, but is preferably 10% by mass or less, more preferably 8% by mass or less.

The reason is that if the content of germanium in the solder exceeds 10% by mass, germanium itself may excessively form oxides, which may hinder the joining with the members to be joined instead.

The lower limit of the germanium content is not particularly limited, for example, it is preferably more than 0.5% by mass, more preferably more than 0.7% by mass.

When the solder is melted, excess oxygen may be gasified to generate voids in the solder. In particular, when the solder is melted for joining in a vacuum environment, the gas such as oxygen expands, and voids are likely to be generated in the solder. In addition, the airtightness between the members to be joined may decrease due to the gap.

In contrast, by making the content of germanium in the solder more than 0.5% by mass, it is possible to suppress the generation of voids in the solder caused by excess oxygen as described above, and especially improve the airtightness between the members to be joined, so it is more good. (Nickel) The said solder contains nickel (Ni) as mentioned above.

The reason for this is that when the solder is melted, nickel contained in the solder has a strong tendency to become an oxide. Therefore, when the bonding portion of the member to be bonded, such as the bonding surface of the circuit board, contains oxide, the oxide and solder in the bonding portion are easily combined, and the wettability of the solder and the bonding portion containing oxide is improved. , can play a higher bonding strength.

The content of nickel in the above-mentioned solder is not particularly limited, and preferably has a fixed relationship with the content of germanium.

Specifically, it is preferable that the content [Ni] of nickel converted in mass % and the content [Ge] of germanium converted in mass % satisfy the following formula (1).

[Ni]≦2.8×[Ge] ^0.3 ···(1) The reason is that if the nickel content [Ni] in terms of mass % of the solder exceeds 2.8×[Ge] ^0.3 , in order to coat the solder When the solder is melted on the joint surfaces of the members to be joined, a part of the solder melts and remains in the form of particles, which may make it impossible to join.

In particular, the content of nickel [Ni] converted in mass % and the content of germanium [Ge] converted in mass % are more preferably satisfying [Ni]≦2.4×[Ge] ^0.3 , and more preferably satisfying [Ni]≦ 2.0×[Ge] ^0.3 .

The lower limit of the content of nickel in the above-mentioned solder is not particularly limited, as long as it is more than 0% by mass.

Also, the value obtained by dividing the nickel content [Ni] in mass % conversion by the germanium content [Ge] in mass % conversion is preferably less than 2.0, more preferably less than 1.5. That is, [Ni]/[Ge]<2.0 is preferable, and [Ni]/[Ge]<1.5 is more preferable.

The reason is that when [Ni]/[Ge] is 2.0 or more, a nickel oxide film may be formed on the surface of the molten solder to be applied to the joint surface of the members to be joined, which may hinder the joining. worry. In addition, the oxide film of nickel means that nickel in a metal component contains relatively many oxide films.

Also, the value obtained by dividing the nickel content [Ni] in mass % conversion by the germanium content [Ge] in mass % conversion is preferably at least 0.005, more preferably at least 0.01. That is, it is preferably 0.005≦[Ni]/[Ge], more preferably 0.01≦[Ni]/[Ge].

The reason is that when [Ni]/[Ge] is less than 0.005, the solder cannot hold sufficient oxygen. There is a risk of impairing the airtight seal between the members to be joined due to reduced performance.

Furthermore, the sum of the content of germanium and the content of nickel is preferably more than 1.2% by mass. This is because, when the sum of the content of germanium and the content of nickel in the solder is more than 1.2% by mass, the hermeticity between the members to be joined can be particularly improved. (Iridium) The said solder may further contain iridium (Ir).

When the above-mentioned solder contains iridium, it is possible to reduce the occurrence of voids in the solder when the solder is melted. The inclusion of iridium in the solder suppresses the generation of voids when the solder is melted. The reason for this is not clear, but it is presumed that the reason is that the surface tension of the molten metal can be lowered to reduce entrainment of gas.

Since generation of voids can be reduced when melting the solder in this way, a sufficient bonding area with the member to be bonded can be ensured, and thus bonding strength can be improved. In addition, since the occurrence of leakage paths can be suppressed, the airtightness between the members to be joined can be improved.

In addition, the coarsening of the eutectic crystals in the solder exists when the solder is melted and solidified to form a joint with the members to be joined, which reduces the elongation and strength of the joint, and becomes a part of the joint. The situation of the cause of the crack. However, when the solder contains iridium, the coarsening of the crystals of the eutectic can be suppressed, and the generation of cracks that cause a decrease in airtightness can be suppressed.

In addition, solder is usually processed into a linear shape and used as a linear solder, but a linear solder containing coarse crystals is brittle and difficult to use. On the other hand, when the said solder contains iridium, the coarsening of the crystal of the eutectic thing in a solder can be suppressed. Therefore, when the said solder contains iridium, even when it is a linear solder, it can suppress that workability|operativity falls.

The eutectic contained in the so-called solder here includes, for example, Ge—Ni eutectic containing germanium and nickel.

The content of iridium in the solder is not particularly limited, for example, it is preferably at most 0.1% by mass, more preferably at most 0.025% by mass, and still more preferably at most 0.005% by mass.

The reason for this is that when the content of iridium in the solder exceeds 0.1% by mass, an oxide film may be formed on the surface when the solder is melted, which may hinder the joining of members to be joined.

In addition, when the content of iridium in the solder is 0.025% by mass or less, the airtightness between members to be joined can be particularly improved, which is more preferable.

The lower limit of the content of iridium is also not particularly limited, for example, it may be set at 0% by mass or more, preferably at least 0.0005% by mass. (Zinc) The said solder may further contain zinc (Zn).

When the solder contains zinc, the zinc tends to become an oxide when the solder is melted. Therefore, when the joint portion of the member to be joined contains oxide, the oxide at the joint portion and the solder become easily combined, the wettability of the solder and the joint portion containing the oxide is improved, and a high joint can be exhibited. strength.

The content of zinc in the above-mentioned solder is not particularly limited, but is preferably 0.5% by mass or less.

The reason for this is that when the content of zinc in the solder exceeds 0.5% by mass, an oxide film may be formed on the surface when the solder is melted, which may hinder the joining of members to be joined.

The lower limit of the content of zinc is also not particularly limited, for example, it may be set to 0% by mass or more. (Oxygen) Furthermore, the above-mentioned solder may further contain oxygen.

Oxygen in the solder becomes a component that promotes the bonding between the solder and the bonding portion containing the oxide when the bonding portion of the member to be bonded contains an oxide.

The state of oxygen contained in the solder is not particularly limited. For example, oxygen is preferably contained in a form melted in the metal material of the solder. This is because, at the interface between the solder and the member to be joined, the oxygen concentration gradient between the oxide of the joining portion of the member to be joined and the metal material in the solder becomes smooth, and the joining interface becomes firm.

The method of adding oxygen to the solder is not particularly limited, and examples thereof include a method of melting in an oxygen-containing atmosphere to produce solder, and/or a method of performing a joining operation with a member to be joined in an oxygen-containing atmosphere.

Furthermore, it is preferable that the solder before being joined to the member to be joined satisfies the content of oxygen in the solder described below. Therefore, it is preferable to adjust the oxygen concentration by a method of producing solder by melting in an atmosphere containing oxygen.

In particular, it is more preferable that the content of oxygen in the solder described below is satisfied in both the state of the solder before joining the member to be joined and the solder after joining.

The content of oxygen in the solder is not particularly limited, for example, it may be 0.0001% by mass or more, preferably 0.0007% by mass or more.

The reason for this is that the effect of improving the joint strength can be sufficiently exhibited by making the content of oxygen 0.0001% by mass or more.

The upper limit of the content of oxygen in the solder is not particularly limited, for example, it may be 2% by mass or less, preferably 1% by mass or less.

The reason for this is that if the amount of oxygen contained in the solder becomes too large, precipitation of oxides will easily occur inside the solder, and there is a possibility that the joint strength may decrease on the contrary. Therefore, as described above, the content of oxygen in the solder is preferably 2% by mass or less.

Furthermore, the content of oxygen in the solder referred to here means the content of oxygen contained in the solder. That is, when an oxide film is formed on the solder surface, it represents the oxygen content in the solder after removing the oxide film.

When measuring the amount of oxygen in the solder, the method of removing the oxide film is not particularly limited, for example, it can be removed by treating the surface of the solder with acid or the like.

The oxygen content in the solder can be measured, for example, in the following procedures (1) to (3). (1) As a sample for analysis, prepare a 0.5 g small piece of the prepared solder. (2) In order to eliminate the influence of the oxide film contained on the surface of the small piece of solder prepared in (1), chemical etching is performed.

Specifically, the beaker containing the small piece of solder and 2-fold diluted hydrochloric acid was set in a water bath, and heated at 80° C. for 12 minutes. Thereafter, decantation was performed with deaerated water, followed by decantation with ethanol. (3) The oxygen concentration was measured for the solder sample after removing the oxide film in (2). The measurement of oxygen concentration can be performed using an oxygen-hydrogen analyzer, for example.

Although each component which the said solder can contain has been demonstrated so far, it is not limited to this material. In addition, the above-mentioned solder may contain, for example, unavoidable components generated at the time of solder preparation. It does not specifically limit as an unavoidable component. However, when containing one or more elements selected from the group consisting of Fe, Co, Cr, V, Mn, Sb, Pb, Bi, Zn, As, and Cd as unavoidable components, the content of the above elements The total is preferably 1% by mass or less, more preferably 500 ppm or less in total.

The reason for this is that the above-mentioned elements have the effect of reducing the wettability of the solder to the member to be joined, and by setting the total content of the above-mentioned elements to 1% by mass or less, the wetting of the solder to the member to be joined can be suppressed. reduced sex.

Moreover, since Ga, P, and B become the cause of pores, when containing at least one element selected from the group consisting of Ga, P, and B as an unavoidable component, the total content is preferably: 500 ppm or less, more preferably 100 ppm or less in total.

Moreover, it is preferable that the said solder does not contain silver (Ag).

The reason for this is that an intermetallic compound (Ag ₃ Sn ) is formed between the silver system and tin. Furthermore, since Ag ₃ Sn has a high melting point, if it exists on the surface of the solder, there is a possibility that the wettability with the members to be joined may slightly decrease.

The reason for this is that there is no problem with regard to the decrease in wettability with the members to be joined, as long as the solder is used to remove the oxide film using an ultrasonic soldering iron or the like before joining the joint. However, when joining is performed in an environment in which the action of removing the oxide film does not function without using an ultrasonic soldering iron or the like, it becomes a factor that hinders joining.

In addition, the fact that the solder does not contain silver means that the solder is dissolved with acid and analyzed by ICP (Inductively Coupled Plasma, Inductively Coupled Plasma) emission spectrometry, which means that it is below the detection limit.

Furthermore, the above-mentioned solder is preferably a eutectic that exists in an area of 1.0×10 ⁶ μm ² at an arbitrary position in the cross section of the solder, and each eutectic is formed by including the eutectic in In the case of the smallest inner circle, there are no more than two circles with a diameter of 220 μm or more, or no more than one circle with a diameter of 350 μm or more.

In addition, the above-mentioned solder is preferably a eutectic substance having an area of 1.0×10 ⁶ μm ² at any position in the cross section of the solder, and the number of eutectic substances having an area of 2000 μm ² or more is two or less , or less than one eutectic of 4000 μm ² or more.

Furthermore, it is preferable that the above-mentioned solder satisfies either one or both of the above-mentioned requirements regarding the eutectic in a specific region of the cross-section of the solder at least before bonding to the member to be bonded. In particular, it is more preferable that the above-mentioned solder satisfies either or both of the above-mentioned requirements regarding the eutectic in a specific region of the cross section of the solder both before joining with the member to be joined and after joining with the member to be joined. indivual. That is, it is more preferable that the above-mentioned solder satisfies either one or both of the above-mentioned requirements when the eutectic in a specific region of the cross-section of the solder is evaluated at any point in time.

The shape of the above-mentioned region having an area of 1.0×10 ⁶ μm ² at any position is not particularly limited, and may be any shape. Examples of the shape of the above region include square, rectangle, polygon and the like. In the case of a square area, for example, the length of one side can be set to 1.0×10 ³ μm. Moreover, when setting it as a rectangular area, the length of each side can be selected so that the said area can be ensured, for example, it can also set it as the rectangle of 400 micrometers x 2500 micrometers. In the case of a polygonal area, the length of each side can be selected so that the above-mentioned area can be ensured, and the length of each side constituting the polygon is not limited.

Examples of the eutectic contained in the solder include Ge—Ni eutectic containing germanium and nickel.

As mentioned above, the coarsening of the eutectic crystals in the solder exists when the solder is melted and solidified to form a joint with the members to be joined, which reduces the elongation and strength of the joint and becomes a joint. The cause of the cracks in the part. However, when the eutectic in the cross section of the solder satisfies the above conditions, it can be said that the coarsening of the crystals of the eutectic can be suppressed, and the generation of cracks that cause a decrease in airtightness can be suppressed.

In addition, the solder can be processed into a wire shape and used as a wire solder, but when the eutectic in the cross section of the solder satisfies the above conditions, the coarsening of the crystals of the eutectic in the solder can be suppressed, and it can be used as a wire. It has sufficient workability in the case of the shape solder.

As the solder that can be preferably used for the solder layer 122, tin (Sn)-antimony (Sb)-based solder, etc. can also be mentioned, for example, in addition to the above-mentioned solder.

The content of each component of the tin-antimony based solder is not particularly limited, for example, the content of antimony is preferably 1% by mass or more. This is because antimony has an effect of raising the solidus temperature in tin-antimony-based solder, and by making the content of antimony 1% by mass or more, this effect can be exhibited particularly, which is preferable.

Although the upper limit of content of antimony is not specifically limited, For example, it is preferable to set it as 40 mass % or less. The reason for this is that, by setting the content of antimony to 40% by mass or less, it is possible to prevent the solidus temperature from becoming too high and to make it a solder suitable for mounting electronic components.

The tin-antimony based solder can contain tin. Tin can alleviate the difference in thermal expansion between members to be joined such as circuit boards and base metal layers and solder. Furthermore, by containing tin as the main component of solder, the melting point temperature of solder can be made into about 230 degreeC which is the melting point temperature of tin.

The tin-antimony based solder may also be composed of antimony and tin, and in this case, the remainder other than antimony may be composed of tin.

The tin-antimony based solder may contain arbitrary additive components other than antimony and tin, and may contain, for example, one or more selected from silver (Ag), copper (Cu), and the like. Like antimony, silver or copper has the effect of raising the solidus temperature of solder. In this case, antimony may constitute the rest except tin and any additional components.

Although the configuration example of the solder which can be preferably used for the solder layer 122 was demonstrated, the solder used for the solder layer 122 of the window material 10 of this embodiment as mentioned above is not limited to this solder.

The shape of the bonding layer 12 is not particularly limited. For example, as shown in FIG. The bonding layer 12 is arranged along the outer periphery of the substrate 11 of inorganic materials. Furthermore, the bonding layer 12 including the solder layer 122 may have an opening in the center, and the shape of the base 11 of the inorganic material may be seen from the opening. In FIG. 1(B), the substrate 11 of the inorganic material is larger than the bonding layer 12 including the solder layer 122, but it is not limited to this form. For example, it may also be configured such that the outer periphery of the substrate 11 made of an inorganic material coincides with the outer periphery of the bonding layer 12 including the solder layer 122 .

Furthermore, in FIG. 1(B), the solder layer 122 located on the outermost surface of the bonding layer 12 is shown, obtained by using a plane perpendicular to the stacking direction of each layer of the bonding layer 12 (the up-down direction in FIG. 1(A) ). The cross-sectional shape of the bonding layer 12 is preferably the same regardless of the layer.

The manufacturing method of the window material of this embodiment is not particularly limited, and may include the following steps, for example.

That is, the substrate preparation step is to prepare the substrate of the inorganic material. and a bonding layer forming step, which is to form a bonding layer on one surface of the substrate of the inorganic material. The specific operation of the substrate preparation step is not particularly limited, for example, the substrate of the inorganic material may be cut into a desired size, or may be processed so that the shape of the substrate of the inorganic material becomes a desired shape. Furthermore, in the case of disposing an antireflection film on the surface of an inorganic material substrate, the antireflection film may also be formed in this step. The film-forming method of the anti-reflection film is not particularly limited, for example, it can be formed by a dry method or a wet method. Film formation is performed by one or more methods such as methods. In the case of a wet method, film formation can be performed by one or more methods selected from the dipping method, the spray coating method, and the like.

The bonding layer forming step may include, for example: a base metal layer forming step of forming a base metal layer; and a solder layer forming step.

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

Furthermore, as mentioned above, the base metal layer may include a plurality of layers, and each layer may be formed by an arbitrary method.

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

The dipping method is to pre-melt the solder that will become the raw material of the solder layer in the solder melting tank, and immerse the part to form the solder layer of the component that will form the solder layer, such as the substrate of the inorganic material that is equipped with the base metal layer, in the solder melting tank A method of melting solder to form a solder layer.

The coating method using a dispenser is a method in which, for example, a dispenser to which a syringe is connected is applied to a part where a solder layer is to be formed, such as a substrate of an inorganic material provided with a base metal layer, on which a solder layer is to be formed Supply molten solder to form a solder layer.

The printing method is a method of printing solder in a paste form on a member to be formed with a solder layer, for example, a base of an inorganic material on which a base metal layer is disposed, to form a solder layer. Furthermore, heat treatment may be performed after printing as needed.

The laser metal deposition method is a method in which powdery solder is supplied to a member to form a solder layer, for example, a portion of a substrate of an inorganic material on which a base metal layer is disposed to form a solder layer, and by After the laser melts the solder, it is cooled to form a solder layer.

The method of using welding wire is the following method, that is, using solder processed into a wire shape, that is, a wire shape, for example, by an automatic welding robot, etc., on a member to be formed with a solder layer, such as a substrate of an inorganic material provided with a base metal layer The portion where the solder layer is to be formed is supplied with molten solder to form the solder layer.

The manufacturing method of the window material of this embodiment may further include arbitrary steps as needed.

The bonding layer can be formed in a desired shape on one surface 11a of the substrate 11 of the inorganic material as described using FIG. 1(A) and FIG. 1(B).

Therefore, the manufacturing method of the window material of this embodiment may also include, for example, a patterning step. The patterning step is to make the bonding layer into a desired pattern after forming the bonding layer through the base metal layer forming step and the solder layer forming step. Patterning in the form of shapes. In the patterning step, for example, a resist corresponding to the pattern to be formed can be placed on the exposed surface of the solder layer, and the part of the solder layer and the base metal layer not covered by the resist can be etched, etc. patterned by removal. A resist removal step for removing the resist may also be performed after the patterning step.

Furthermore, when the base metal layer includes a plurality of layers, after forming a part of the layers included in the base metal layer, a patterning step may be performed, and the layers included in the formed base metal layer One part is patterned. Then, after the patterning step, a resist removal step for removing the resist may be performed, and then, a remaining base metal layer is further formed on the patterned base metal layer.

Also, for example, the manufacturing method of the window material of this embodiment may also include a resist disposing step. The resist disposing step is performed before the base metal layer forming step and the solder layer forming step without forming the base metal layer, And part of the solder layer is provided with a resist. By forming the base metal layer and the solder layer after the formation of the resist, the base metal layer and the solder layer can be formed only in the portion corresponding to the pattern to be formed. In this case, you may include the resist removal process which removes a resist after a solder layer formation process.

In addition, in order to be able to manufacture a plurality of window materials at the same time, it is also possible to form a plurality of bonding layers corresponding to each window material on the substrate (material before cutting) of a plurality of inorganic materials of a certain size. A cutting step of cutting the matrix of the inorganic material is included. The cutting method is not particularly limited, and cutting methods suitable for substrates of inorganic materials, such as the cutting method using laser light already described, can be used. Furthermore, when the bonding layer is continuously formed in adjacent window materials, that is, when the bonding layer is arranged on the cutting line, the bonding layer may also be cut together in the cutting step.

Furthermore, after the optical package is produced, the substrate of the inorganic material and the like can be cut together with the circuit board to perform singulation.

According to the window material of the present embodiment described above, since the volume ratio of gold in the bonding layer is suppressed, it is possible to obtain a window material with suppressed cost. [Optical Package] Next, an example of the configuration of the optical package according to this embodiment will be described.

The optical package of this embodiment can have the above-mentioned window material and a circuit board equipped with an optical element.

A configuration example of the optical package of this embodiment will be described using FIG. 4 .

FIG. 4 schematically shows a cross-sectional view obtained from a plane parallel to the stacking direction of the window material of the optical package and the circuit board with the optical element of the present embodiment. In addition, in FIG. 4, although the window material 10 and the circuit board 41 are described separately so that they can be distinguished, in the optical package 40, both members are bonded and integrated.

As described above, the optical package 40 of this embodiment has the above-mentioned window material 10 and the circuit board 41 including the optical element 42 .

Since the window material 10 has already been described, the same reference numerals as in the case of FIG. 1 are attached, and the description is omitted.

The circuit board 41 is not particularly limited, and various circuit boards including an insulating base material 411 and unillustrated wiring for supplying power to the optical element 42 can be used.

However, when bonding with the window material 10 , in order to improve the airtightness in the space surrounded by the window material 10 and the circuit board 41 , the circuit board 41 preferably has an insulating base material 411 made of ceramics.

Here, the ceramic material used for the insulating base material 411 of the circuit board 41 is not particularly limited, and examples thereof include alumina (alumina, Al ₂ O ₃ ), aluminum nitride (AlN), LTCC ( One or more of Low Temperature Co-fired Ceramics, Low Temperature Co-fired Ceramics, etc.

The shape of the insulating base material 411 of the circuit board 41 is not particularly limited, but it is preferably constituted in such a manner that when the optical package 40 is produced, the base body 11 of an inorganic material, the insulating base material 411, And the joint part described below forms a space enclosed as a part where the optical element 42 is arranged. Therefore, it is preferable that the insulating base material 411 has an opening in the center of the upper surface 411a, and has a recess 411A as a non-through hole including the opening. Furthermore, the upper surface of the insulating base material 411 refers to the surface facing the window material 10 in the case of forming an optical package, and may also be referred to as the surface of the side bonded to the window material 10 .

The wall portion 411B surrounding the concave portion 411A supports the bonding layer 12 of the window material 10 and the base metal layer for a circuit board described below when the optical package is manufactured, so it can have a connection with the bonding layer 12 or the circuit board. The shape corresponding to the base metal layer for the substrate.

Furthermore, the circuit board 41 may have the circuit board base metal layer 412 on the upper surface 411 a of the insulating base material 411 , that is, the upper surface of the wall portion 411B.

The base metal layer 412 for the circuit board can have the effect of improving the adhesion between the insulating base material 411 of the circuit board 41 and the window material 10 . The specific structure of the base metal layer 412 for circuit boards is not particularly limited. For example, a first base metal layer 412A for circuit boards and a second base metal layer 412A for circuit boards may be stacked sequentially from the side of the insulating base material 411 of the circuit board 41 . Layer structure of base metal layer 412B and base metal layer 412C for third circuit board. Here, an example in which the base metal layer 412 for a circuit board includes three layers is shown, but it is not limited to this form, and may include one layer, two layers, or four or more layers.

When the circuit board base metal layer 412 includes three layers as described above, for example, the first circuit board base metal layer 412A preferably contains the same metal as that used for forming wiring (circuit) on the circuit board 41. Metal. For example, the first base metal layer 412A for a circuit board may be a layer containing one or more metals selected from copper (Cu), silver (Ag), and tungsten (W). The first base metal layer 412A for circuit boards may be a layer containing one or more metals selected from copper (Cu), silver (Ag), and tungsten (W). In this case, it is not excluded that the first base metal layer 412A for circuit boards contains unavoidable impurities.

The second base metal layer 412B for circuit boards may be a layer that prevents alloying between the third base metal layer 412C for circuit boards and the first base metal layer 412A for circuit boards described later, and may be a layer containing nickel (Ni), for example. . The second base metal layer 412B for a circuit board may be a layer made of nickel (Ni). In this case, it is not excluded that the second circuit board base metal layer 412B contains unavoidable impurities.

The third base metal layer 412C for circuit boards may be a layer for preventing oxidation of the second base metal layer 412B for circuit boards, and may be a layer containing gold (Au), for example. 412 C of base metal layers for 3rd circuit boards may be made of gold (Au). In this case, it is not excluded that the third circuit board base metal layer 412C contains unavoidable impurities.

The thickness of each layer constituting the base metal layer 412 for a circuit board is not particularly limited, and can be selected arbitrarily.

The thickness of the first circuit board base metal layer 412A is preferably, for example, set to 1 μm or more. The upper limit of the thickness of the first base metal layer 412A for circuit boards is also not particularly limited, but it is preferably 20 μm or less from the viewpoint of sufficiently reducing costs.

The thickness of the second circuit board base metal layer 412B is preferably 1 μm or more from the viewpoint of suppressing alloying between the first circuit board base metal layer 412A and the third circuit board base metal layer 412C. The upper limit of the thickness of the second base metal layer 412B for circuit boards is also not particularly limited, but it is preferably 20 μm or less from the viewpoint of sufficiently reducing costs.

The thickness of the third base metal layer 412C for circuit boards is preferably 0.03 μm or more from the viewpoint of preventing oxidation of other base metal layers for circuit boards. The upper limit of the thickness of the third circuit board base metal layer 412C is not particularly limited, but it is preferably 2.0 μm or less, more preferably 0.5 μm or less, from the viewpoint of sufficiently reducing costs.

There is no particular limitation on the shape of the base metal layer 412 for the circuit board. Since the joint layer 12 of the window material 10 forms the joint portion 43 described below when the optical package 40 is produced, it is preferable to have a The shape corresponding to the joint layer 12 of 10 . Specifically, it is preferable to be the cross-sectional shape of the bonding layer 12 of the window material 10 and the base metal layer 412 for the circuit board in a plane perpendicular to the lamination direction (the up-down direction in FIG. 4 ) of the two members when forming an optical package. are the same shape.

The film-forming method of the base metal layer 412 for circuit boards is not specifically limited, For example, it can select arbitrarily according to the kind etc. of the base metal layer 412 for circuit boards to be formed into a film. For example, film formation can be performed by a dry method or a wet method, and in the case of a dry method, film formation can be performed by one or more methods selected from vapor deposition, sputtering, and ion plating. In the case of a wet method, film formation can be performed by one or more methods selected from electroplating, electroless plating, and printing.

Furthermore, as already mentioned, the base metal layer for circuit boards may include a plurality of layers, and each layer may be formed by an arbitrary method.

The optical element 42 arranged on the circuit board 41 is not particularly limited, and for example, a light emitting element such as a light emitting diode, a light receiving element, or the like can be used.

Furthermore, when the optical element 42 is a light emitting element, the wavelength region of the light emitted by the light emitting element is not particularly limited. Therefore, for example, a light-emitting element that emits light in an arbitrary wavelength range selected from ultraviolet light to infrared light, ie, light in an arbitrary wavelength range selected from a wavelength range of 200 nm to 1 mm, for example, can be used.

However, according to the optical package of this embodiment, the base of the window material as a member for transmitting light from the light-emitting element is not a transparent resin base but an inorganic material base 11 . Therefore, compared with the case where a transparent resin base is used as the base of the window material, the airtightness can be improved, and further, deterioration of the window material due to light from the light emitting element can be suppressed. Therefore, when the optical element is a light-emitting element, when a light-emitting element that is particularly required to be airtight or a light-emitting element that emits light that easily deteriorates the resin is used, the optical package of this embodiment can be used particularly well. effect, and better. As a light-emitting element that requires airtightness in particular, for example, a light-emitting element that emits UV-C, which is light in a wavelength region having a wavelength of 200 nm to 280 nm, can be cited. In addition, as a light-emitting element that emits light that facilitates deterioration of the resin, a light-emitting element that emits light with a high output such as laser light can be cited. Therefore, when the optical element 42 is a light-emitting element, a light-emitting element emitting UV-C, a laser, or the like can be preferably used as the light-emitting element from the viewpoint of exerting a particularly favorable effect.

Furthermore, the base 11 of the inorganic material of the window material 10 and the insulating base material 411 of the circuit board 41 can be bonded by the bonding part 43 . As shown in FIG. 4 , the bonding portion 43 may have the bonding layer 12 of the window material 10 and the circuit board base metal layer 412 of the circuit board 41 . Furthermore, the junction part 43 may also include the junction layer 12 and the base metal layer 412 for circuit boards.

The configuration of the joint portion 43 is not particularly limited, but from the viewpoint of cost, the volume ratio of gold in the joint portion is preferably 5% or less, more preferably 4% or less.

Since the joint part 43 does not need to contain gold, the volume ratio of gold in the joint part can be made 0 or more.

Each layer, such as the above-mentioned solder layer or base metal layer, included in the bonding portion 43 can be formed with a substantially uniform thickness. Therefore, for example, when the layer containing gold exists in the form of a gold layer composed of gold in the junction 43, the volume ratio of gold can also be set as the ratio of the thickness of the gold layer to the thickness of the junction 43. ratio. Also, when the gold-containing layer also contains components other than gold, the ratio of the thickness of the gold-containing layer to the thickness of the joint portion 43 can be multiplied by the ratio of the gold in the gold-containing layer. The value obtained from the volume content ratio.

In addition, when calculating the volume ratio of the gold in a joint part using the thickness of each layer as mentioned above, the average value of simple average can be used as the thickness of a solder layer.

According to the optical package of this embodiment described above, since the above-mentioned window material is used, it can be set as an optical package with reduced cost.

The manufacturing method of the optical package of this embodiment is not specifically limited, It can manufacture by arbitrary methods.

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

That is, the circuit board preparation step prepares a circuit board provided with an optical element.

The bonding step is to arrange the window material on the circuit substrate, and bond the window material and the circuit substrate.

In the circuit board preparation step, an optical element may be arranged on a conventionally manufactured circuit board to prepare a circuit board equipped with an optical element. Furthermore, in the case of performing singulation after the bonding step is completed, in the circuit board preparation step, a circuit board before cutting in which a plurality of circuit boards are integrated can be prepared.

Then, in the bonding step, the window material can be arranged on the circuit substrate, and the window material can be bonded to the circuit substrate. The specific method of bonding is not particularly limited. For example, first, in the optical package 40 shown in FIG. 412a overlaps in direct contact. Then, for example, by pressing from the other side 11b of the base 11 of the inorganic material of the window material 10 toward the circuit board 41 side, that is, pressing along the block arrow B in the figure, and heating the solder layer 122 At least a part thereof is melted and then cooled, thereby bonding the window material 10 and the circuit board 41 .

In the bonding step, it is preferable that the oxide film present on the surface of the lower surface 12a of the bonding layer 12 melts into the inside of the solder layer 122 melted by heating, and the solder layer 122 is so thin that the melted solder layer 122 can be connected to the circuit. The extent of the upper surface 412a of the base metal layer 412 for the substrate. The specific thickness of the oxide film is not limited, and the thickness of the oxide film is preferably less than 10 nm, more preferably less than 5 nm.

Furthermore, the method of pressing the base 11 of inorganic material is not particularly limited, for example, the method of using a pressing mechanism having a pressing member in contact with the base 11 of inorganic material and an elastic body such as a spring applying pressure to the pressing member, Or use the plumb method, etc.

In the optical package obtained after the bonding step, when a specific atmosphere is set in the region sealed by the window material 10 and the circuit board 41, it is preferable to set the specific atmosphere in advance for heat treatment. . For example, an atmosphere selected from atmospheric atmosphere, vacuum atmosphere, inert atmosphere and the like can be used. The inert atmosphere may be an atmosphere containing one or more gases selected from nitrogen, helium, argon, and the like.

In the bonding step, the conditions for performing the heat treatment are not particularly limited, for example, it is preferable to heat to a temperature higher than the melting temperature of the solder in the solder layer. However, if heating is performed rapidly, thermal stress may be applied to the substrate of the inorganic material, and cracks may occur. Therefore, for example, it is preferable to first raise the temperature to the first melting point of the solder that is 50° C. or higher and does not reach the solder layer. After the heat treatment temperature, keep 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 at least 30 seconds, more preferably at least 60 seconds. 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 raised to a second heat treatment temperature of a temperature higher than the melting point of the solder as the solder layer. Moreover, in order to fully bond the window material 10 and the circuit board 41, the second heat treatment temperature is preferably above the melting point of the solder + 20° C. In the case where the optical element on the substrate is damaged by heat, the second heat treatment temperature is preferably 300° C. or lower, for example. The holding time at the second heat treatment temperature is not particularly limited, but it is preferably 20 seconds or more in order to fully bond the window material 10 and the circuit board 41 . However, in order to more reliably suppress the adverse effect of heat on the optical element, the holding time at the second heat treatment temperature 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 bonding step is completed.

The manufacturing method of the optical package of this embodiment may contain arbitrary steps as needed. For example, when a plurality of circuit boards are integrated and not singulated into one circuit board, the cutting step may be included in the bonding step. The cutting method used in the cutting step is not particularly limited, and cutting can be performed by any method. The circuit board and the window material can also be cut into pieces simultaneously by the cutting method using laser light described in the description of the window material. Also, a plurality of cutting methods may be combined. Example

Hereinafter, specific examples are given and described, but the present invention is not limited to these examples.

First, the evaluation methods of window materials and optical packages produced in the following examples will be described. (Hermeticity test) For the optical packages using the window materials produced in the following examples, the airtightness test is carried out immediately after production, or after reflow treatment or heat cycle test under specific conditions, And evaluate the airtight sealing characteristics.

The airtightness test was carried out in accordance with JIS Z 2331:2006. Specifically, it was carried out in the following order.

First, the optical package to be evaluated was placed in a pressurized container, and held for 2 hours under the condition of pressurizing helium (He) to 5.1 atmosphere in the pressurized container (pressurization step). After the pressurization step, the optical package to be evaluated was taken out from the pressurized container, and the leakage of helium (He) was measured in the vacuum container within 1 hour after taking out (helium leakage measurement step). When the leakage rate of helium gas (He leakage rate) measured in the helium gas leakage measurement step is 4.9×10 ^-9 Pa·m ³ /s or less, it is judged as acceptable (judgment step). Furthermore, in the judging step, when the He leak rate exceeds 4.9×10 ^-9 Pa·m ³ /s, it is judged as unacceptable. [Example 1] (Window material) The window material shown in Fig. 1(A) and Fig. 1(B) was produced.

Specifically, a disc-shaped plate made of quartz having a thickness of f100 mm and a thickness of 0.5 mm was prepared as a material before cutting the substrate of the inorganic material (substrate preparation step).

Then, a bonding layer was formed on one surface of the substrate of the inorganic material before cutting in the following procedure (bonding layer forming step).

First, by ion beam evaporation, the first base metal layer and the second base metal layer are sequentially formed from the non-cutting material side of the inorganic material substrate on the entire surface of the non-cutting material side of the inorganic material substrate. 2 Base metal layer (base metal layer forming step).

A chromium (Cr) layer with a thickness of 0.03 μm was formed as the first base metal layer, and a copper (Cu) layer with a thickness of 0.2 μm was formed as the second base metal layer.

Next, after applying a resist to the entire surface of the second base metal layer and the surface opposite to the surface facing the first base metal layer, that is, the exposed surface, the resist is exposed using ultraviolet rays. , and further develop to arrange a patterned resist (resist arrangement step). The patterned resist is set to have a quadrangular shape in cross-section taken from a plane parallel to one surface of the material before cutting the substrate of the inorganic material, and has a quadrangular opening in the center. .

Then, after patterning is performed by etching a portion not covered with the resist in the first base metal layer and the second base metal layer with an etching solution, the resist is removed (resist removal step).

Next, on the patterned first base metal layer and the second base metal layer, a nickel (Ni) layer with a thickness of 0.8 μm was formed by electroless nickel plating as a third base metal layer. Thereby, a patterned base metal layer including the first base metal layer, the second base metal layer, and the third base metal layer is formed.

Second, a solder layer is formed on the base metal layer. The solder used for the solder layer is prefabricated in the following order.

Components contained in the solder were weighed, mixed, and melted so that 97.499% by mass of Sn, 1.5% by mass of Ge, 1.0% by mass of Ni, and 0.001% by mass of Ir were melted to temporarily prepare a raw material alloy. Then, after melting this raw material alloy, it pours into a mold, and a solder is produced.

Then, the solder used as the raw material of the solder layer is melted in advance in a solder melting tank, and the portion of the substrate of the inorganic material on which the base metal layer is arranged to form the solder layer is immersed in the solder melted in the solder melting tank, and then Cooling, whereby a solder layer is formed (solder layer forming step).

Furthermore, the melting point of the above-mentioned solder used for forming the solder layer is 230° C., the density is 7.3 g/cm ³ , and the coefficient of thermal expansion is 22.9 ppm. Also, copper corrosivity was 7.47%.

The melting point was measured by using DSC (differential scanning calorimeter, differential scanning calorimeter) (manufactured by Shimadzu Corporation, model: DSC-60) and heating at 10°C/min. Density was measured by the Archimedes method.

The coefficient of thermal expansion was measured using a vertical dilatometer (Model: DL-7000 manufactured by Vacuum Riko). When the measurement was performed, the measurement was performed by raising the temperature at 5° C./min in a temperature range of 23° C. to 200° C. under an argon atmosphere.

Copper corrosion was evaluated in the following order.

Cut 2 copper wires with a diameter of 0.5 mm to a length of about 3 mm, and dip the two copper wires in RMA (Rosin Mildly activated, weakly activated rosin) type flux to remove the oxide film on the surface.

The first copper wire after removing the oxide film was cleaned with ethanol, and the cross-sectional area S ₁ of the first copper wire was measured. Furthermore, the cross-sectional area of the copper wire means the cross-sectional area of the copper wire obtained by using a plane perpendicular to the longitudinal direction.

Next, the 2nd copper wire from which the oxide film was removed was immersed in the solder bath which added the said solder and heated so that the temperature of the hot water might become 400 degreeC for 60 seconds. At this time, in order to prevent the oxide film from reproducing on the copper wire, dip it in a solder bath within 60 seconds after removing the oxide film with flux. After immersion in the solder tank, the copper wire was pulled up, and the copper wire was ground from the end dipped in the solder tank, and the cross-sectional area S ₂ of the copper wire was measured at the position where the copper cross-section could be confirmed.

The ratio of the reduction in cross-sectional area to the cross-sectional area S ₂ of the copper wire after dipping in the solder pot was calculated relative to the cross-sectional area S ₁ of the copper wire before dipping in the solder pot. Specifically, it calculated by the following formula. (Copper Corrosion)=(S ₁ -S ₂ )/S ₁ ×100 In the evaluation of copper corrosion, a digital microscope (manufactured by KEYENCE Co., Ltd. model: VHX-900) was used in the measurement of the cross-sectional area of the copper wire. , and the image processing software accompanying the digital microscope.

Moreover, the Young's modulus was calculated from the result of the tensile test for the obtained solder, and it was confirmed that it was 20 GPa. The tensile test was carried out on a JIS14A test piece at a tensile speed of 3 mm/min using a tensile testing machine (Autograph AGX-100kN manufactured by Shimadzu Corporation).

The average value of the thickness of the solder layer and the calculation method of the weighted average value will be described using FIG. 3 . FIG. 3 is a diagram for explaining measurement points, and is a diagram corresponding to FIG. 1(B). In the present embodiment, as described above, the bonding layer including the solder layer is formed on one surface of the material before cutting of the base of the inorganic material so as to correspond to the plurality of window materials. Therefore, the thickness of the solder layer was divided into individual pieces by cutting, and the solder layer included in one window material was arbitrarily selected and evaluated. Therefore, in FIG. 3, the solder layer 122 contained in one window material used for measurement after singulation, and the base body 11 of an inorganic material are shown.

In the case of singulation, the solder layer 122 has a strip shape along the outer periphery of the inorganic material base 11 in a cross section perpendicular to the stacking direction of the inorganic material base 11 and the solder layer 122 .

Furthermore, the solder layer is formed by the dipping method as described above, and is introduced into the solder melting tank along the straight line B5 in FIG. 3 . Therefore, the thickness of the solder layer is symmetrical about the center of the straight line B5.

Therefore, using a laser microscope (manufactured by KEYENCE Co., Ltd. model: VK-8510), measure the thickness of the solder layer at the five locations of the measurement points Z1, Z2, Z3, Z4, and Z8 in Figure 3. For the measurement points Z5~Z7 The thickness T _Zx at the place is set as T _Z1 =T _Z7 , T _Z2 =T _Z6 , and T _Z3 =T _Z5 . Then, the average value of the thickness of 8 points of measurement point Z1~Z8 was calculated, and the result was 29.31 μm in simple average.

Also, using the measured values of the thickness at T _Z1 ~ T _Z4 and T _Z8 at the measurement points Z1, Z2, Z3, Z4, and Z8, the weighted average value of the solder layer 122 is calculated according to the formula (1), and the result can be confirmed The weighted average is 20.14 μm.

Furthermore, as mentioned above, since the thickness of the solder layer is symmetrical about the center of the straight line B5, it is also set as T _Z1 =T _Z7 , T _Z2 =T _Z6 , and T _Z3 =T _Z5 when calculating the weighted average. calculate. The formula (1) has already been explained, so the explanation is omitted here.

Also, the length L1 of one side of the opening is the average of the lengths of one side of the opening measured along the straight lines B2, B3, and B5 measured at both ends and the center of the opening. Regarding the length L2 of one side of the opening, the average value of the lengths of one side of the opening measured along the straight lines A2, A3, and A5 is also used in the same manner.

For each line width W1~W4 of the solder layer, the average value of the line widths measured at multiple points is also used. In the case of the line widths W1 and W2, the values measured along the straight line B5 passing through the center of the long side direction of the sides 304 and 302 and the values measured along the straight lines B2 and B3 passing through the two ends of the opening are respectively used. The average value of the measured values at 3 points. In the case of line widths W3 and W4, use the values measured along the straight line A5 passing through the center of the longitudinal direction of the sides 301 and 303, and the values measured along the straight lines A2 and A3 passing through the two ends of the opening. The average value of the measured values at 3 points.

Calculations were performed in the above order. As a result, it was confirmed that the maximum value of the deviation of the thickness of the solder layer from the simple average value, that is, the maximum deviation, was 10 μm, and the maximum value of the deviation from the weighted average value, that is, the maximum deviation was 19 μm.

After the solder layer 122 is formed, as shown in FIG. 5 , a substrate 50 with patterned bonding layers 52 corresponding to a plurality of window materials is obtained on one surface of the pre-cut material 51 of the inorganic material base. Then, by aligning the focus of the laser light at an arbitrary position in the thickness direction of the material 51 before cutting the substrate of the inorganic material, and scanning the irradiation position of the laser light along the contour of the patterned bonding layer 52, The pre-cutting material 51 of the inorganic material matrix is cut by applying a force so that the portion through which the focal position of the laser light passes becomes a fulcrum. In addition, the laser beam is scanned once along the line to cut. Therefore, as shown in FIG. 2 , the side surface of the singulated inorganic material substrate 11 has a linear pattern 111 along the outer periphery of one side 11 a and the other side 11 b.

Through the above steps, as shown in FIG. 1(B), the shape of the solder layer 122 along the inorganic The matrix 11 of the material is arranged on the outer periphery, and has a quadrangular opening in the center, and the matrix 11 of the inorganic material can be seen from the opening. Furthermore, in FIG. 1(B) the solder layer 122 located on the outermost surface is shown, but the cross-sectional shape of the bonding layer 12 obtained by using the plane parallel to the surface 11a of the substrate 11 of the inorganic material becomes the same as that shown in FIG. 1(B) The solder layer 122 has the same shape.

Moreover, the bonding layer 12 including the base metal layer 121 and the solder layer 122 is formed along the outer periphery of the substrate 11 of the inorganic material as described above. Either of W4 (see FIG. 3 ) is 0.65 mm.

The window material is manufactured through the above steps.

Furthermore, since the window material 10 does not include a layer containing gold, the volume ratio of gold in the bonding layer becomes zero. Therefore, it was confirmed that the cost of the joining material can be significantly reduced to about 25% compared with the conventional window material using the AuSn alloy.

In addition, the thickness of the oxide film on the surface of the solder layer 122 of the window material 10 was measured using an XPS (X-ray photoelectron spectrum, X-ray photoelectron spectrum) measuring device (Quantera SXM (manufactured by ULVAC-PHI)). The thickness of the film was 5 nm. (Optical package) Using the above-mentioned window material and the circuit board 41 including the optical element 42, the optical package 40 shown in FIG. 4 was manufactured.

As the circuit board 41, an insulating base material 411 made of aluminum oxide (alumina) with an external shape of 5.8 mm square and a height of 1.28 mm and having wiring not shown in the figure was used. Moreover, the insulating base material 411 of the circuit board 41 has an opening part formed in the center part of the upper surface 411a, and has the recessed part 411A which is a non-through hole including this opening part. The concave portion 411A is configured such that the optical element 42 can be disposed at the bottom thereof. In addition, the upper surface 411a of the insulating base material 411 becomes the surface which opposes the window material 10 when the optical package 40 is manufactured. Also, the opening has a quadrangular shape, and the concave portion 411A is a quadrangular prism-shaped cavity (corner prism) surrounded by the wall portion 411B.

Furthermore, the circuit board 41 has the circuit board base metal layer 412 on the upper surface 411a of the insulating base material 411 so as to surround the above-mentioned opening and along the outer periphery of the upper surface 411a of the insulating base material 411 .

As the base metal layer 412 for circuit boards, a first base metal layer 412A for circuit boards, a second base metal layer 412B for circuit boards, and a third base metal layer for circuit boards are stacked in order from the insulating base material 411 side. Layer structure of the metal layer 412C.

A silver (Ag) layer with a thickness of 10 μm was formed as the base metal layer 412A for the first circuit board, and a nickel (Ni) layer with a thickness of 5 μm was formed as the second base metal layer 412B for the circuit board with a thickness of 0.4 μm. A gold (Au) layer of μm is used as the base metal layer 412C for the third circuit board.

The base metal layer 412 for a circuit board is set in a shape corresponding to the bonding layer 12 of the window material 10 . Specifically, it is configured such that, with regard to the cross-sectional shape in a plane perpendicular to the stacking direction (up-down direction in FIG. 4 ) of the bonding layer 12 of the window material 10 and the base metal layer 412 for a circuit board, It has the same shape as the base metal layer 412 for circuit boards. Therefore, the outer shape of the base metal layer 412 for circuit boards is 5 mm square, and the line width is set to 0.65 mm.

An optical element (model number: OSBL1608C1A manufactured by OptoSupply Co., Ltd.) was placed on the bottom of the above-mentioned concave portion 411A, and connected to wiring not shown in the figure.

Then, the window material 10 and the circuit board 41 provided with the optical element 42 are bonded according to the following procedure, and the optical package 40 is manufactured (bonding process).

First, the upper surface 412a of the circuit board base metal layer 412 of the circuit board 41 with the optical element 42 and the lower surface 12a on the solder layer 122 side of the bonding layer 12 of the window material 10 are arranged to face and contact each other.

Then, from the other side 11b of the base body 11 of the inorganic material of the window material 10, by a pressing mechanism having a pressing member in contact with the base body 11 of the inorganic material and a spring applying pressure to the pressing member, along the block arrow B is placed in a heat treatment furnace under pressure.

Next, the atmosphere in the heat treatment furnace was made into a vacuum atmosphere, and after raising the temperature from 23° C. to 80° C. as the first heat treatment temperature, it was held for 300 seconds. Next, after raising the temperature to 280°C as the second heat treatment temperature and maintaining it for 30 seconds, the heater was turned off and cooled to 23°C.

The optical package is manufactured according to the above sequence.

The junction portion 43 of the obtained optical package has only the third base metal layer 412C for a circuit board as a layer containing gold, and the gold calculated from the thickness of the junction portion 43 and the thickness of the third base metal layer 412C for a circuit board is used for the junction. The volume ratio occupied by the portion 43 is 0.87%.

In addition, in order to implement the following reflow test and heat cycle test, 7 optical packages were manufactured under the same conditions. (Evaluation) (1) Hermeticity test without heat treatment After the manufacture of one optical package, the aforementioned hermeticity test was implemented, and the result was judged to be acceptable. (2) Airtightness test after reflow test Also, the following reflow tests 1 to 3 were implemented on the three optical packages respectively.

As reflow test 1, one optical package was placed in a reflow furnace and heated once with the temperature profile shown in FIG. 6 .

As reflow test 2, one optical package was placed in a reflow furnace and heated repeatedly three times with the temperature distribution shown in FIG. 6 .

As reflow test 3, one optical package was placed in a reflow furnace, and heated five times with the temperature distribution shown in FIG. 6 .

For the optical packages after the above reflow test 1~3, carry out the airtightness test respectively, and the result is that any optical package is qualified. (3) Airtightness test after thermal cycle test The following thermal cycle tests 1 to 3 were performed on the three optical packages respectively.

As thermal cycle test 1, one optical package was subjected to 100 thermal cycles of maintaining at -40°C for 30 minutes and then maintaining at 85°C for 30 minutes.

As thermal cycle test 2, one optical package was subjected to 500 thermal cycles of maintaining at -40°C for 30 minutes and then maintaining at 85°C for 30 minutes.

As thermal cycle test 3, one optical package was subjected to 200 thermal cycles of maintaining at -40°C for 30 minutes and then maintaining at 100°C for 30 minutes.

For the optical packages after the thermal cycle test 1~3 above, carry out the airtightness test respectively, and the result is that any optical package is qualified.

According to the optical package of the present embodiment, since the ratio of gold occupied in the bonding portion is suppressed, a cost-reduced optical package can be obtained.

Also, as described above, it was confirmed that high airtightness can be maintained not only immediately after manufacture but also after a reflow test or a heat cycle test is performed. It can be considered that the reason is that since the Young's modulus of the solder used for the solder layer of the window material is 20 GPa, which is relatively low, no cracks in the substrate 11 of the inorganic material, and the substrate 11 of the inorganic material and the circuit have not occurred. Peeling of the substrate 41, etc. [Example 2] (Window material) The window material shown in FIG. 1(A) and FIG. 1(B) was produced and evaluated according to the following procedures.

Also in the present example, similarly to the case of Example 1, a disc-shaped plate made of quartz was prepared as a material before cutting the substrate of the inorganic material (substrate preparation step).

Next, a bonding layer was formed on one surface of the substrate of the inorganic material before cutting in the following procedure (bonding layer forming step).

On one surface of the substrate of the inorganic material before cutting, a base metal layer in a lattice pattern is formed by ion beam evaporation or electroless plating (base metal layer forming step).

Specifically, first, a chromium (Cr) layer with a thickness of 0.2 μm is formed by ion beam evaporation sequentially from the side of the substrate 11 of the inorganic material as the first base metal layer 121A, and a copper (Cr) layer with a thickness of 0.2 μm is formed. Cu) layer as the second base metal layer 121B.

Next, by applying a resist on the entire surface of the second base metal layer opposite to the surface facing the first base metal layer, that is, the exposed surface, and then exposing the resist to ultraviolet rays, Furthermore, development is performed, and the patterned resist is arrange|positioned (resist arrange|positioning process). The patterned resist is set to have a quadrangular shape in cross-section taken from a plane parallel to one surface of the material before cutting the substrate of the inorganic material, and has a quadrangular opening in the center. .

Then, the resist is removed after patterning the first base metal layer and the second base metal layer by etching the parts not covered with the resist (resist removal step).

Then, on the patterned first base metal layer and the second base metal layer, a nickel-boron alloy (Ni-B) layer with a thickness of 0.8 μm was formed by electroless nickel-boron alloy plating as 3rd base metal layer.

Next, the solder layer 122 was formed on the base metal layer 121 in the same manner as in the first embodiment. Furthermore, the solder layer 122 uses the same solder as in the first embodiment.

Then, in the same manner as in Example 1, the pre-cut material 51 (see FIG. 5 ) of the inorganic material base is cut and separated into pieces. In this way, a window material with a matrix of inorganic materials of 5 mm square was obtained.

Since the obtained window material did not include a layer containing gold, the volume ratio of gold in the bonding layer was zero. The side surface of the inorganic material substrate after singulation is as shown in FIG. 2 , and the linear pattern 111 becomes a linear pattern parallel to one side 11 a and the other side 11 b of the inorganic material substrate 11 .

The line width and the length of one side of the solder layer 122 of the window material 10 were measured using an optical microscope (BX51TRF manufactured by Olympus), and the line widths W1-W4 were 0.3 mm, and the lengths L1 and L2 of one side of the opening were 3.0 mm.

The line widths W1 to W4 and the lengths L1 and L2 of one side of the opening were measured and calculated in the same manner as in Example 1, and therefore descriptions thereof are omitted here.

Regarding the thickness of the solder layer, use a laser microscope (manufactured by KEYENCE Co., Ltd. model: VK-8510) to measure the three window materials of sample 1 to sample 3 cut from the material before cutting from the substrate of the same inorganic material. The measurement of 8 points of measurement points Z1~Z8 shown in Figure 3. Then, using the obtained measured values, the average value (simple average value) of the thickness of the solder layer was calculated|required about each sample, and the weighted average value was calculated|required using the formula (1) mentioned above. The results are shown in Table 1.

(光學封裝) 使用上述窗材製作圖4所示之光學封裝。[Table 1]

(Optical package) The optical package shown in FIG. 4 was produced using the above-mentioned window material.

As the circuit board 41, an insulating base material 411 made of aluminum oxide (alumina) with an external shape of 5.8 mm square and a height of 1.28 mm and having wiring not shown in the figure was used. Moreover, the insulating base material 411 of the circuit board 41 has an opening part formed in the center part of the upper surface 411a, and has the recessed part 411A which is a non-through hole including this opening part. The concave portion 411A is configured such that the optical element 42 can be disposed at the bottom thereof. Furthermore, the upper surface 411a of the insulating base material 411 becomes the surface facing the window material 10 when the optical package 40 is produced. Also, the opening has a quadrangular shape, and the concave portion 411A is a quadrangular prism-shaped cavity (corner prism) surrounded by the wall portion 411B.

Furthermore, the circuit board 41 has the circuit board base metal layer 412 on the upper surface 411a of the insulating base material 411 so as to surround the above-mentioned opening and along the outer periphery of the upper surface 411a of the insulating base material 411 .

As the base metal layer 412 for circuit boards, a first base metal layer 412A for circuit boards, a second base metal layer 412B for circuit boards, and a third base metal layer for circuit boards are stacked in order from the insulating base material 411 side. Layer structure of the metal layer 412C.

A tungsten (W) layer with a thickness of 10 μm was formed as the base metal layer 412A for the first circuit board, and a nickel (Ni) layer with a thickness of 3 μm was formed as the base metal layer 412B for the second circuit board with a thickness of 2 μm. A gold (Au) layer of μm is used as the base metal layer 412C for the third circuit board.

The base metal layer 412 for a circuit board is set in a shape corresponding to the bonding layer 12 of the window material 10 . Specifically, it is configured such that, with regard to the cross-sectional shape in a plane perpendicular to the stacking direction (up-down direction in FIG. 4 ) of the bonding layer 12 of the window material 10 and the base metal layer 412 for a circuit board, It has the same shape as the base metal layer 412 for circuit boards. Therefore, the outer shape of the base metal layer 412 for a circuit board is 3.6 mm square, and the line width is set to 0.3 mm.

An optical element (model number: OSBL1608C1A manufactured by OptoSupply Co., Ltd.) was placed on the bottom of the above-mentioned concave portion 411A, and connected to wiring not shown in the figure.

Then, the window material 10 and the circuit board 41 provided with the optical element 42 are bonded according to the following procedure, and the optical package 40 is manufactured (bonding process).

First, the upper surface 412a of the circuit board base metal layer 412 of the circuit board 41 with the optical element 42 and the lower surface 12a on the solder layer 122 side of the bonding layer 12 of the window material 10 are arranged to face and contact each other.

Then, from the other side 11b of the base body 11 of the inorganic material of the window material 10, by a pressing mechanism having a pressing member in contact with the base body 11 of the inorganic material and a spring applying pressure to the pressing member, along the block arrow B is placed in a heat treatment furnace (under a nitrogen atmosphere) under a state where pressure (200 g) is applied. Then, the window material 10 and the circuit board 41 are fusion-bonded with the temperature distribution shown in FIG. 7 to form an optical package.

Specifically, after raising the temperature from 23° C. to 80° C. as the first heat treatment temperature, it was held for 300 seconds. Next, after raising the temperature to 280°C as the second heat treatment temperature and maintaining it for 60 seconds, the heater was turned off and cooled to 23°C.

The junction portion 43 of the obtained optical package has only the third base metal layer 412C for a circuit board as a layer containing gold, and the gold calculated from the thickness of the junction portion 43 and the thickness of the third base metal layer 412C for a circuit board is used for the junction. The volume ratio occupied by the part 43 is 3.0%~3.4%. (Evaluation) The airtightness test was carried out on the obtained optical package, and the result was acceptable. [Example 3] An optical package was produced in the same manner as in Example 2, except that the atmosphere in the heat treatment furnace when bonding the window material 10 and the circuit board 41 was an atmospheric atmosphere (air atmosphere) instead of a nitrogen atmosphere.

The airtightness test was carried out on the obtained optical package, and the result was acceptable. [Example 4] When manufacturing a window material, after forming the solder layer 122, when performing singulation, the number of scans of the laser light is set to 2 times, except for this point, the window material is produced in the same manner as in Example 2, and Optical packaging.

Specifically, when the laser light is irradiated for the first time, in the thickness direction of the material before cutting the substrate of the inorganic material, it is set at a position farther from the laser light incident surface, and the laser light is directed along the planned cutting line. The irradiation position moves. Then, when the laser light is irradiated for the second time, the focus position of the laser light is changed to a position closer to the incident surface of the laser light than the first time, and the irradiation position of the laser light is similarly moved along the planned cutting line.

After the second irradiation of the laser light, the pre-cut material of the substrate of the inorganic material is cut by applying a force so that the position through which the focus position of the laser light passes becomes a fulcrum.

Thus, as shown in FIG. 8 , it was confirmed that two linear patterns 811 and 812 were generated on the side surface of the substrate 11 of the inorganic material after singulation, which can be considered to be caused by a change in the bonding state of the inorganic material. Furthermore, the two linear patterns 811, 812 have a shape along the outer circumference of one surface 11a and the other surface 11b.

Furthermore, even when the output of the laser is changed, it can be confirmed that the pattern of the same shape is obtained on the cut surface.

In this case, it is also possible to separate into pieces without causing defects such as chipping, cracking, and chipping in the substrate 11 of the inorganic material.

The surface roughness of the linear patterns 811 and 812 produced at this time was measured using a laser microscope (model: VK-8510 manufactured by KEYENCE Co., Ltd.). As a result, the surface roughness Ra was 0.3 μm. The surface roughness of the region 82 in between, the surface roughness Ra is 1.1 μm. From the evaluation results of the surface roughness, it was also confirmed that the bonded state of the inorganic material was changed in the linear pattern 811 and other parts.

An optical package was produced in the same manner as in Example 2 except for using the obtained window material.

The airtightness test was carried out on the obtained optical package, and the result was acceptable.

The window material and the optical package have been described above based on the embodiments, examples, and the like, but the present invention is not limited to the above-mentioned embodiments, examples, and the like. Various changes and modifications can be made within the scope of the gist of the present invention described in the claims.

This application claims priority based on Japanese Patent Application No. 2017-122542 filed with the Japan Patent Office on June 22, 2017, and the entire content of Japanese Patent Application No. 2017-122542 is incorporated in this international application.

10‧‧‧window material 11‧‧‧inorganic material substrate 11a‧‧‧one side 11b‧‧‧the other side 12‧‧‧bonding layer 12a‧‧‧lower surface 31A‧‧‧corner 31B‧‧‧corner 31C ‧‧‧Corner 31D‧‧‧Corner 32A‧‧‧Side 32B‧‧‧Side 32C‧‧‧Side 32D‧‧‧Side 40‧‧‧optical package 41‧‧‧circuit board 42‧‧ ‧Optical element 43 ‧‧‧joining part 50‧‧‧substrate 51‧‧‧material 52‧‧‧joining layer 82‧‧‧area 111‧‧‧linear pattern 121‧‧‧base metal layer 121A‧‧ ‧First base metal layer 121B ‧‧‧recess 411a‧‧‧upper surface 411B‧‧‧wall portion 412‧‧‧circuit board base metal layer 412A‧‧‧first circuit board base metal layer 412a‧‧‧upper surface 412B‧‧‧second Circuit board base metal layer 412C‧‧‧Third circuit board base metal layer 811‧‧‧Linear pattern 812‧‧‧Linear pattern A‧‧‧Block arrow A1‧‧‧Straight line A2‧‧‧Straight line A3‧ ‧‧Straight line A4‧‧‧Straight line A5‧‧‧Straight line B‧‧‧Block arrow B1‧‧‧Straight line B2‧‧‧Straight line B3‧‧‧Straight line B4‧‧‧Straight line B5‧‧‧Straight line L1‧‧‧Opening Length of one side L2‧‧‧length of one side of the opening W1‧‧‧line width W2‧‧‧line width W3‧‧‧line width W4‧‧‧line width Z1‧‧‧measurement point Z2‧‧‧measurement point Z3‧‧‧measurement point Z4‧‧‧measurement point Z5‧‧‧measurement point Z6‧‧‧measurement point Z7‧‧‧measurement point Z8‧‧‧measurement point

Fig. 1 (A), (B) is the structure explanatory drawing of the window material of this embodiment. Fig. 2 is an explanatory diagram of a configuration example of a side surface of a substrate of an inorganic material. Fig. 3 is an explanatory view showing the positions of the measurement points for the thickness of the solder layer of the window material. Fig. 4 is an explanatory view showing the structure of the optical package of the present embodiment. Fig. 5 is an explanatory diagram of the material before cutting of the substrate of the inorganic material before singulation in the embodiment. FIG. 6 is an explanatory diagram of the temperature distribution of the reflow test in Example 1. FIG. FIG. 7 shows the temperature distribution of the bonding step in Example 2. FIG. FIG. 8 is an explanatory view of the linear pattern produced on the side surface of the substrate of the inorganic material after singulation in Example 4. FIG.

10‧‧‧window materials

11‧‧‧The matrix of inorganic materials

11a‧‧‧one side

11b‧‧‧the other side

12‧‧‧joining layer

121‧‧‧base metal layer

121A‧‧‧The first base metal layer

121B‧‧‧The second base metal layer

122‧‧‧Solder layer

A‧‧‧Block Arrow

Claims (8)

A window material, which is used for optical packaging of optical elements, and has: a base of inorganic materials; and a bonding layer, which is arranged on one surface of the base of inorganic materials; the volume ratio of gold in the bonding layer is 10 % or less, the bonding layer has a base metal layer and a solder layer, and the average thickness of the solder layer is 5 μm or more and 50 μm or less. The window material according to claim 1, wherein the deviation of the thickness of the above-mentioned solder layer is ±20 μm or less. The window material according to claim 1 or 2, wherein the Young's modulus of the solder constituting the solder layer is 50 GPa or less. The window material as in Claim 1 or 2, wherein the solder constituting the above-mentioned solder layer contains tin, germanium, and nickel, the content of the above-mentioned germanium is 10% by mass or less, and the content of the above-mentioned germanium and the content of the above-mentioned nickel satisfy the following formula (1 ): [Ni]≦2.8×[Ge] ^0.3 ... (1) (where [Ni] represents the content of nickel converted in mass %, and [Ge] represents the content of germanium converted in mass %). The window material as claimed in claim 1 or 2, wherein the side surface of the matrix of the above-mentioned inorganic material has a A linear pattern on the outer periphery of one side. An optical package, which has the window material according to any one of claims 1 to 5, and a circuit substrate with optical elements. The optical package according to claim 6, wherein the circuit board has an insulating base material made of ceramics. The optical package according to claim 6 or 7, wherein the substrate of the inorganic material of the above-mentioned window material and the insulating base material of the above-mentioned circuit board are joined by a joint part, and the volume ratio of gold in the above-mentioned joint part is 5% or less .

Images