JP7150026B2 - substrate - Google Patents

Description

The present disclosure relates to substrates.

Patent Document 1 describes Al ₂ O ₃ , Si, Ti, Mn, Fe, Cr, etc. as an example of the composition of black ceramics, and as coloring materials for blackening, Fe, Cr, Co, It is described that Mn, Ni, Cu, etc. are used.

JP-A-8-17388

The substrate of the present disclosure is made of an aluminum oxide ceramic containing a titanium oxide whose composition formula is TiO _2-x (1≦x<2), and the total content of Fe, Ni, Co, Mn and Cr is 260 mass ppm or less.

FIG. 1 is a schematic diagram showing the configuration of a lamp device having a substrate according to an embodiment of the present disclosure and mounted on the front right side of a vehicle. FIG. 2 is a schematic diagram showing the configuration of a first sensor module arranged in the lamp device shown in FIG. FIG. 3 is a schematic diagram showing the configuration of a head-up display including a substrate according to an embodiment of the present disclosure. FIG. 4 is a schematic diagram showing the configuration of a test device including a substrate according to an embodiment of the present disclosure. 5 is a side view showing the configuration of the movable part and the heat source part of the test apparatus shown in FIG. 4. FIG. FIG. 6 is a graph showing measurement results of reflectance in Examples.

<Substrate>
Hereinafter, a (circuit) board according to an embodiment of the present disclosure will be described in detail.
The substrate of the present embodiment is made of an aluminum oxide ceramic containing titanium oxide with a composition formula of TiO _2-x (1≦x<2), and contains a total of Fe, Ni, Co, Mn and Cr. The amount is 260 mass ppm or less. With such a configuration, the reflectance is low over a wide wavelength range. In addition, the ultraviolet (UV) absorption effect of the titanium oxide can suppress deterioration due to sunlight and protect the members mounted on the substrate, so long-term use is possible. Furthermore, when exposed to sunlight, the photocatalytic effect of the titanium oxide is exhibited, and dirt on the members mounted on the substrate can be removed. The configuration of the substrate of this embodiment will be specifically described below.

The aluminum oxide ceramics are ceramics in which the content of aluminum oxide, converted to Al ₂ O ₃ , is 90% by mass or more in 100% by mass of all components constituting the ceramics. A titanium oxide having a composition formula of TiO _2-x (1≦x<2) is a reduced titanium oxide (TiO ₂ ). The crystal phase of titanium oxide may be rutile titanium oxide. Also, the total content of Fe, Ni, Co, Mn and Cr may be 170 mass ppm or less.

The substrate of this embodiment presents a black color with a sufficiently low reflectance for light in a relatively wide wavelength range. Specifically, the lightness index L* in the CIE1976L*a*b* color space is 48 or less, and the chromaticness indices a* and b* are -2 or more and 5 or less and -10 or more and 0 or less, respectively. The value of the lightness index L* and the values of the chromaticness indices a* and b* in the CIE1976L*a*b* color space can be obtained in accordance with JIS Z 8722:2009. For example, a spectral color difference meter (NF777 manufactured by Nippon Denshoku Industries Co., Ltd. or its successor model) may be used, and the light source may be set to CIE standard light source D65 and the viewing angle to 2°.

The substrate of this embodiment has a maximum reflectance value Rmax of 24% or less over a wavelength of 250 nm to 2500 nm, and a difference ΔR between the maximum value Rmax and the minimum value Rmin of 15.3% or less. That is, the substrate of this embodiment has a low reflectance in the wavelength range of 250 nm to 2500 nm, and the variation in the wavelength distribution of the light intensity of the reflected light with respect to the irradiation light is small. The substrate of this embodiment has a uniformly low reflectance over such a wide wavelength range.

In the substrate of the present embodiment, the content of titanium oxide whose composition formula is TiO _2-x (1≦x<2) is, for example, 0.5% out of 100% by mass of all components constituting the ceramics. It is more than mass % and below 4 mass %. When the content of titanium oxide is within the range described above, a black color with sufficiently suppressed chroma and low reflectance can be obtained, and the volume resistivity at room temperature (5 to 35 ° C.) is It has electrical insulation of 10 ⁹ Ω·m or more. Moreover, from the viewpoint of further enhancing insulation, the volume resistivity of the substrate of the present embodiment may be, for example, 10 ⁸ Ω·m or more at 200°C. Normally, the higher the temperature, the lower the volume resistivity, but the substrate of this embodiment has insulating properties even at a high temperature of 200.degree. Here, the volume resistivity can be determined according to JIS C 2141:1992. Note that the upper limit of the volume resistivity is not particularly limited.

The substrate may be free of aluminum titanate. When such a structure is satisfied, since aluminum titanate, which has a large difference in coefficient of linear expansion with respect to aluminum oxide, does not exist in the substrate, minute cracks are less likely to occur even if heating and cooling are repeated. Whether or not the substrate contains aluminum titanate can be determined by comparing an X-ray chart obtained using an X-ray diffractometer (XRD) with the JCPDS card (No. 00-041-0258).

The substrate of the present embodiment has a total content of Fe, Ni, Co, Mn and Cr of 260 ppm by mass or less, that is, a maximum content of Cr alone is 260 ppm by mass. When Cr is contained in alumina, light in the wavelength range of 700 nm or more and less than 780 nm (hereinafter also referred to as short wavelength range light) or wavelength range of 780 nm or more and less than 1590 nm (hereinafter referred to as long wavelength range light However, since the substrate of the present embodiment has a low Cr content, the reflectance in the short wavelength region and the long wavelength region is low.

If the Cr content in the substrate is 40 ppm by mass or less, the reflectance for light in a relatively wide wavelength range will be sufficiently low.

Further, if the Fe content in the substrate is 100 ppm by mass or less, an increase in reflectance due to discoloration can be further suppressed, resulting in a lower reflectance in the visible light region and (near) infrared region.

Further, if the substrate has a Ni content of 10 mass ppm or less, a Co content of 5 mass ppm or less, or a Mn content of 100 mass ppm or less, changes in mechanical strength and electrical properties are small.

The substrate may contain oxides of silicon, calcium and magnesium in the grain boundary phase that binds the crystal grains of aluminum oxide. Here, the total content of oxides of silicon, calcium and magnesium is, for example, 2% by mass or more and 4% by mass or less in 100% by mass of all components constituting the ceramics. Further, when the total content of oxides of silicon, calcium, and magnesium is 100% by mass, the content of oxides of calcium and oxides of magnesium is 10% by mass or more and 30% by mass or less, and the balance is It may be an oxide of silicon. When the contents of oxides of silicon, calcium and magnesium are within the above ranges, the substrate has a volume resistivity of 10 ¹¹ Ω·m or more, or 10 ¹² Ω·m or more at room temperature.

The crystal phase of titanium oxide in the substrate can be identified by XRD, and the value of x can be determined using a transmission electron microscope (TEM).

In addition, the content of aluminum, silicon, calcium, magnesium and titanium converted to oxides was measured using an X-ray fluorescence spectrometer (XRF) or an ICP (Inductively Coupled Plasma) emission spectrometer (ICP). are obtained and converted into Al ₂ O ₃ , SiO ₂ , CaO, MgO and TiO _2-x (1≦x<2), respectively. The contents of Fe, Ni, Co, Mn and Cr may be determined using a glow discharge mass spectrometer (GDMS).

In addition, the aluminum oxide ceramics forming the substrate is inexpensive, and a high dielectric constant equivalent to that of high-purity and expensive aluminum oxide ceramics having a titanium oxide content of less than 0.1% by mass can be obtained. can.

The substrate of the present embodiment may have a portion with an average skewness Rsk of 0.04 or more and 0.45 or less. When the substrate has such portions, the reflectance is low. The average value of all skewnesses Rsk on the substrate may be 0.04 or more and 0.45 or less.

Further, the substrate of the present embodiment may have a portion where the average value of kurtosis Rku is 4.1 or more and 6.5 or less. When the substrate has such portions, the reflectance is low. The average value of all kurtosis Rku in the substrate may be 4.1 or more and 6.5 or less.

Furthermore, the substrate of this embodiment may have a portion where the average value of the arithmetic mean roughness Ra is 1 μm or more and 2 μm or less. When the substrate has such portions, the reflectance is low. Note that the average value of all arithmetic mean roughnesses Ra on the substrate may be 1 μm or more and 2 μm or less.

The skewness Rsk, kurtosis Rku, and arithmetic mean roughness Ra can be determined according to JIS B 0601:2001, for example, using a laser microscope (manufactured by KEYENCE CORPORATION (VK-9510)). The measurement conditions are as follows: color ultra-depth measurement mode, measurement magnification of 400 times, measurement range of 698 μm×522 μm, measurement pitch of 0.05 μm, λs contour filter of 2.5 μm, and λc contour filter of 0.08 mm. The average value of the measured values obtained from the eight measurement ranges may be used as the average value of the skewness Rsk, the kurtosis Rku, and the arithmetic mean roughness Ra.

Further, the aluminum oxide ceramics may have a light-shielding surface, and the light-shielding surface may have a color difference Δ*Eab of 4.5 or less in the CIE1976L*a*b* color space.

The color difference Δ*Eab is an index indicating variations in color tone perception, and is represented by the following formula (1).
ΔE*ab=[(ΔL*) ² +(Δa*) ² +(Δb*) ² ] ^1/2 (1)
(ΔL* is the difference between the lightness index L ₁ * of the first measurement target point on the light shielding surface and the lightness index L ₂ * of the second measurement target point, Δa* is the chromaticness index of the first measurement target point on the light shielding surface The difference between a ₁ * and the brightness index a ₂ * of the second measurement target point, Δb*, is the chromaticness index b ₁ * of the first measurement target point on the light-shielding surface and the brightness index b ₂ * of the second measurement target point. is the difference.)

When the color difference Δ*Eab is within the above range, variations in the color tone of the light-shielding surface are reduced, making it difficult to visually recognize the variations, thereby improving commercial value.

Further, the variation coefficient of the lightness index L* in the CIE1976L*a*b* color space of the light shielding surface may be 0.02 or less (excluding 0).

When the coefficient of variation of the lightness index L* is within the above range, the light-shielding surface is in a state where it is difficult to discolor even if it is repeatedly irradiated with light, and therefore it is difficult to change over time. Here, the average value of the lightness index L* of the light shielding surface is, for example, 48 or less.

The value of the lightness index L* and the values of the chromaticness indices a* and b* in the CIE1976L*a*b* color space of the light shielding surface can be obtained by the same method as described above.

Further, the aluminum oxide ceramics may have open pores, and the skewness of the equivalent circle diameter of the open pores may be 0.1 or more and 2 or less.

When the skewness of the equivalent circle diameter of the open pores is 0.1 or more, the distribution of the equivalent circle diameter of the open pores tends to be smaller, and the floating metal powder and the powder exhibiting a bright white color enter the open pores. As a result, variations in the color tone of the light-shielding surface are reduced, and the commercial value is improved.

The average equivalent circle diameter of the open pores is, for example, 4 μm or more and 6 μm or less. Moreover, the porosity of the open pores is 3 area % or more and 6 area % or less.

In order to obtain the circle-equivalent diameter and porosity of the open pores, first, the holding member was ground on a cast iron surface plate using diamond abrasive grains having an average particle diameter D50 of 3 μm, and then the average particle diameter _D50 was determined to be _0.5 μm. A surface to be measured is obtained by polishing with a tin surface plate using diamond abrasive grains of 5 μm.

Then, an optical microscope is used at a magnification of 100 times, and an average portion of the measurement surface is selected and photographed with a CCD camera. Next, among the photographed images, four areas each having an area of 2.27×10 ² μm are set, and image analysis software (eg, Win ROOF manufactured by Mitani Shoji Co., Ltd.) is used. Equivalent circle diameter and porosity of the open pores can be obtained by analyzing the In the analysis, the threshold value of the equivalent circle diameter of the open pores is 0.8 μm, and the equivalent circle diameter of less than 0.8 μm is not analyzed.

Then, the skewness of the circle-equivalent diameter of the open pores can be obtained using the function SKEW provided in Excel (registered trademark, Microsoft Corporation).

The shape of the substrate is not particularly limited, and any desired shape can be adopted according to the member to be mounted.

(Substrate manufacturing method)
Next, an example of the method for manufacturing the substrate of this embodiment will be described.

First, powders of aluminum oxide, silicon oxide, calcium carbonate, magnesium hydroxide and titanium oxide are prepared.

The total content of the powders of calcium carbonate, magnesium hydroxide and silicon oxide is, for example, 6.5% by mass or more and 12.9% by mass or less with respect to the total 100% by mass of the powders. The content of the calcium carbonate, magnesium hydroxide and silicon oxide powders is 17.8% by mass or more and 53.4% by mass or less of the total 100% by mass of these powders. , the content of magnesium hydroxide powder is 14.4% by mass or more and 43.2% by mass or less, and the balance is silicon oxide powder.
In particular, the content of magnesium hydroxide is preferably 30% by mass or more and 44% by mass or less of the content of titanium oxide. When the content of magnesium hydroxide is within the above range, the formation of anorthite and mullite, which are likely to occur in the reduction treatment described later, is suppressed. Since anorthite and mullite have different average linear expansion coefficients than aluminum oxide, if the formation of these compounds is suppressed, cracks will not occur even if the substrate is used in an environment where it is repeatedly exposed to heating and cooling. less likely to occur.

The content of the titanium oxide powder is, for example, 0.5% by mass or more and 4% by mass or less in the total 100% by mass of each powder of aluminum oxide, silicon oxide, calcium carbonate, magnesium hydroxide, and titanium oxide, The balance is aluminum oxide powder.

Then, these powders are wet-mixed and pulverized by a pulverizer such as a barrel mill, rotary mill, vibration mill, bead mill, agitator mill, atomizer, or attritor to obtain a slurry. In the above pulverization, a solvent, an organic binder such as polyvinyl alcohol (PVA) in an amount of 1 part by mass or more and 1.5 parts by mass or less per 100 parts by mass of the solvent, and 0.1 part by mass per 100 parts by mass of the solvent 1 part or more and 0.5 parts or less by mass of a dispersant is put into the pulverizer together. Next, the resulting slurry is demagnetized and then spray-dried to obtain granules. The demagnetization process removes the ferromagnetic metals Fe, Ni and Co.

Also, the content of Fe, Ni, Co, Mn and Cr in the substrate is affected by wear of the stainless steel members used in the crusher. Stainless steel members that wear out due to long-term use, for example, should be replaced with titanium parts that tend to form a passive film on the surface, or titanium-based films such as TiN, TiCN, TiC, TiAlN, TiAlCN, and TiAlO, or non-metallic films. Crystalline hard carbon (DLC) may be coated on the surface of the stainless steel member. In addition to the demagnetization treatment, such substitution or coating of the stainless steel member makes it possible to obtain a substrate having a total content of Fe, Ni, Co, Mn and Cr of 260 ppm by mass or less.

Then, the granules are molded by a dry pressing method or a cold isostatic pressing method (CIP), and then subjected to cutting to obtain a molded body. Thereafter, the obtained compact is fired in an air (oxidizing) atmosphere at a temperature of 1500° C. or higher and 1700° C. or lower for a predetermined period of time to obtain a sintered body.
Here, in order to obtain a substrate in which the skewness of the average pore diameter of open pores is 0.1 or more and 2 or less, the molding pressure should be, for example, 1500 MPa or more and 4000 MPa or less.

In addition, you may grind-process after baking. Further, if necessary, a vibrating barrel polishing machine may be used to perform polishing while adjusting the abrasive material, the frequency of vibration and the polishing time to obtain a predetermined surface property.

Then, the sintered body obtained by the above method is placed in a mixed gas having a nitrogen:hydrogen ratio of 87 to 90% by volume: 10 to 13% by volume as a reducing atmosphere at 1300 ° C. or higher and 1400 ° C. or lower. The substrate of the present embodiment can be obtained by holding at the temperature of 1 hour or more and 2 hours or less.
In order to obtain a substrate having a color difference Δ*Eab of 4.5 or less in the CIE1976L*a*b* color space of the light-shielding surface, the content of titanium oxide powder is adjusted to aluminum oxide, silicon oxide, calcium carbonate, magnesium hydroxide. 1.8% by mass or more and 3% by mass or less of the total 100% by mass of each powder of titanium oxide and titanium oxide, and held at a temperature of 1330° C. or more and 1400° C. or less for 1 hour or more and 2 hours or less.
In order to obtain a substrate in which the coefficient of variation of the lightness index L* in the CIE1976L*a*b* color space of the light-shielding surface is 0.02 or less (excluding 0), the content of the titanium oxide powder is adjusted to the amount of aluminum oxide. , silicon oxide, calcium carbonate, magnesium hydroxide, and titanium oxide, in a total of 100% by mass, 1.8% by mass or more and 3% by mass or less, at a temperature of 1350°C or more and 1400°C or less for 1 hour or more and 2 hours. The following should be retained.

The substrate of the present embodiment described above has low reflectance in the visible light region and (near) infrared region, and can be used for a long period of time. can be used for

<In-vehicle optical equipment>
Next, a lamp device and a head-up display will be exemplified as examples of in-vehicle optical devices provided with the substrate of the present embodiment, and will be described in order using the drawings. However, for convenience of explanation, each drawing referred to below shows only the configuration necessary for explaining the embodiment in a simplified manner. Therefore, the vehicle-mounted optical device of the present disclosure may have any configuration not shown in the referenced figures. In addition, the dimensions of the configuration in the drawings do not faithfully represent the dimensions and dimensional ratios of the actual configuration.

(Lamp device)
In the following description, a configuration in which the lamp device is mounted on the front right side of the vehicle will be described as an example, but the lamp device of the present disclosure is not limited to a configuration that is mounted on the front right side of the vehicle as long as it functions.

As shown in FIG. 1 , the lamp device 20 according to the embodiment of the present disclosure includes a light-transmitting cover 21 positioned in the traveling direction of the vehicle, a housing 22 positioned on the opposite side of the light-transmitting cover 21 , and the light-transmitting cover 21 . and a headlamp 24 , a first sensor module 25 and a second sensor module 26 , respectively located inside a lamp chamber 23 surrounded by a housing 22 .

The headlamp 24 has optical components including at least one of a lens and a reflector. The light emitted from the headlamp 24 passes through the translucent cover 21 and illuminates the right front of the vehicle. Since the lamp device 20 is provided with such a headlight 24, it functions as a headlight.

The first sensor module 25 includes a first substrate 251 (support member). The first substrate 251 supports a first visible light camera 252, a first LiDAR (Light Detection and Ranging) sensor 253, and a first light shielding member 254 (shielding member). , a communication unit 256 and a power supply unit 257 . The first substrate 251 is a substrate on which a sensor circuit including a first visible light camera 252, a first LiDAR sensor 253, a control section 255, a communication section 256 and a power feeding section 257 is mounted. That is, a plurality of sensors (first visible light camera 252 and first LiDAR sensor 253) with different detection methods, a first light shielding member 254 that is a cylindrical hollow member surrounding these sensors, and a circuit that operates these sensors are modularized on the first substrate 251 .

As shown in FIG. 1, the first visible light camera 252 captures the right side of the vehicle. That is, the first visible light camera 252 is a sensor that detects information on the right side of the vehicle.

As shown in FIG. 2, the first LiDAR sensor 253 includes a light-emitting portion 253a that emits infrared light and a light-receiving portion 253b that detects the reflected light of the infrared light that bounces off an object on the right side of the vehicle.

The first LiDAR sensor 253 can obtain the distance to the object based on the time it takes to detect the reflected light from the object after the infrared light is emitted in a certain direction. Further, by accumulating and analyzing distance measurement values in association with detection positions, it is possible to obtain information about the shape of the object. Information such as the material of the object associated with the reflection can be obtained based on the difference in wavelength between the emitted light and the reflected light. Furthermore, based on the difference in the reflectance of the reflected light, it is possible to obtain information about the color of the object (such as white lines on the road surface). That is, the first LiDAR sensor 253 can obtain various information on the right side of the vehicle in a different way from the first visible light camera 252 .

In addition, as shown in FIG. 1 , the first sensor module 25 includes a first actuator 258 (an example of an adjustment mechanism) coupled to the first substrate 251 . First actuator 258 adjusts at least one of the position and attitude of first substrate 251 with respect to the vehicle.

The second sensor module 26 also has a second substrate 261 . The second substrate 261 supports a second visible light camera 262, a second LiDAR sensor 263, a millimeter wave radar 264, and a second light shielding member 265, which is a tubular hollow member surrounding these, all of which are not shown. It also supports the control section, communication section and power supply section.

The functions of the second visible light camera 262 and the second LiDAR sensor 263 are the same as the functions of the first visible light camera 252 and the first LiDAR sensor 253, respectively, so description thereof will be omitted.

The millimeter wave radar 264 has a transmitter that transmits millimeter waves and a receiver that receives the reflected waves of the millimeter waves that bounce off at least an object present in front of the right side of the vehicle. The frequencies of millimeter waves are, for example, 24 GHz, 26 GHz, 76 GHz or 79 GHz.

The millimeter wave radar 264 can determine the distance to the object based on the time it takes to detect the reflected light from the object after the infrared light is emitted in a certain direction. Further, by accumulating and analyzing distance measurement values in association with detected positions, it is possible to obtain information related to the movement of an object. That is, the millimeter wave radar 264 can obtain information on the right front of the vehicle by a method different from that of the second visible light camera 262 or the second LiDAR sensor 263 .

In addition, the second sensor module 26 includes a second actuator 266 (an example of an adjustment mechanism) coupled to the second substrate 261 . Second actuator 266 adjusts at least one of the position and attitude of second substrate 261 with respect to the vehicle.

The lamp device 20 also includes a signal processing section 27 located outside the lamp chamber 23 . The signal processing section 27 is configured to output a first drive signal 271 for driving the first actuator 258 and a second drive signal 272 for driving the second actuator 266 . The first drive signal 271 includes information for adjusting the position and/or orientation of the first actuator 258 and the second drive signal 272 includes information for adjusting the position and/or orientation of the second actuator 266. .

In the lamp device 20, at least one of the first substrate 251 of the first sensor module 25 and the second substrate 261 of the second sensor module 26 is made of the above-described substrate of the present embodiment. As described above, the substrate of this embodiment has a low reflectance over a wide wavelength range, so noise in the projected image can be reduced. In addition, the UV absorption effect of titanium oxide can suppress deterioration due to sunlight, protecting the components mounted on the substrate (visible light camera, LiDAR sensor, light shielding component, control unit, communication unit, power supply unit, etc.). can be used for a long period of time. Furthermore, when exposed to sunlight, the photocatalytic effect of the titanium oxide is exhibited, and dirt on the members mounted on the substrate can be removed.

The lamp device 20 also includes a light source element mounting board on which light source elements (such as LEDs) of the headlamp 24 are mounted as a board around the optical path. Further, in the lamp device 20, the light source element mounting board is made of the board of the present embodiment. In other words, the substrate of this embodiment may be used for a light source element of a headlight. With such a configuration, stray light can be removed by the low reflectance of the substrate of this embodiment, so unnecessary reflection or scattering on the optical path can be reduced, and noise in the projected image can be reduced. In addition, the photocatalytic effect of the oxide of titanium prevents contamination around the light source element and maintains the brightness for a long period of time.

The lamp device 20 includes a CMOS mounting board for mounting a CMOS (Complementary Metal Oxide Semiconductor) image sensor in the first visible light camera 252 as a board around the optical path. In the lamp device 20, the CMOS mounting substrate is made of the substrate of this embodiment. In other words, the substrate of this embodiment may be used for a vehicle-mounted camera. According to such a configuration, the noise of the projected image can be reduced due to the low reflectance of the substrate of the present embodiment in the visible light region and the (near) infrared region. In addition, the photocatalytic effect of titanium oxide can prevent contamination in the vicinity of the CMOS image sensor to maintain sensitivity.

The lamp device 20 includes a light-receiving element mounting substrate for mounting the light-receiving element in the light-receiving section 253b of the first LiDAR sensor 253 as a substrate around the optical path. In the lamp device 20, the light-receiving element mounting substrate is made of the substrate of this embodiment. In other words, the substrate of this embodiment may be for LiDAR. According to such a configuration, noise can be reduced by the low reflectance of the substrate of the present embodiment in the near-infrared region, and as a result, the detection performance of the first LiDAR sensor 253 is enhanced. Further, the photocatalytic effect of titanium oxide can prevent contamination of the light-receiving element and maintain the sensitivity.

The lamp device 20 also includes the same substrates as the first visible light camera 252 and the first LiDAR sensor 253 described above for the second visible light camera 262 and the second LiDAR sensor 263 . Further, in the lamp device 20, the substrates of the second visible light camera 262 and the second LiDAR sensor 263 may be composed of the substrate of the present embodiment.

(head-up display)
As shown in FIG. 3 , the head-up display 30 according to the embodiment of the present disclosure includes an in-vehicle projector module 31, a reflecting mirror 32, a microlens array 33, a convex lens 34, and a combiner in order from the image projection side. 35 and .

The in-vehicle projector module 31 projects an image in the direction of arrow a. The in-vehicle projector module 31 includes an optical/MEMS (Micro Electro Mechanical Systems) unit and an RGB light source module housed in the optical/MEMS unit.

The reflecting mirror 32 reflects the image projected from the in-vehicle projector module 31 toward the microlens array 33 . Microlens array 33 functions as an intermediate image screen. The convex lens 34 is adjacent to the microlens array 33 and convex on the combiner 35 side, and functions as a field lens. The combiner 35 reflects the image magnified by the convex lens 34 toward the driver's eyes.

Note that the microlens array 33 and the convex lens 34 are held by a lens holding member 36 . That is, the head-up display 30 includes a lens holding member 36 that holds the microlens array 33 and the convex lens 34 .

Here, the head-up display 30 further has the following configuration in addition to the configuration described above. That is, the head-up display 30 includes a light source element substrate on which the light source elements of the RGB light source module are mounted as a substrate around the optical path. In the head-up display 30, the light source element substrate is made of the substrate of this embodiment. In other words, the substrate of this embodiment may be used for a head-up display. According to such a configuration, the noise of the projected image can be reduced due to the low reflectance of the substrate of the present embodiment over a wide wavelength range. In addition, long-term use is possible due to the antifouling effect of the photocatalyst effect of titanium oxide.

<Test equipment>
The substrate of this embodiment can also be used in test equipment. As an example of test equipment, the test apparatus shown in FIG. 4 and the like will be described as an example. FIG. 4 is a partial cross-sectional view showing the configuration of a test device including a substrate according to an embodiment of the present disclosure.

The test apparatus 40 is an apparatus for measuring static characteristics, dynamic characteristics, and the like of the semiconductor device 41 housed in a package while the temperature of the semiconductor device 41 is raised.

The test apparatus 40 is configured such that the semiconductor device 41 is loaded into the mounting section 42 by a transport mechanism (not shown) and the semiconductor device 41 is unloaded from the mounting section 42 .

The mounting portion 42 includes a mounting table 44 on which the semiconductor device 41 is mounted, and the mounting table 44 is supported from below by a contractible coil spring 43 . When the semiconductor device 41 placed on the mounting table 44 is pressed from above (in the direction of arrow A), the coil spring 43 contracts and the semiconductor device 41 moves downward together with the mounting table 44 . When the mounting table 44 and the semiconductor device 41 move downward, each terminal of the semiconductor device 41 and the contact pin 45 connected to the measurement circuit 46 come into contact with each other and are electrically connected. In preparation for the case where the terminal is large, an auxiliary terminal 47 including an elastic member for receiving pressure from above the semiconductor device 41 is provided on the plate member 48 holding the contact pin 45 . Further, an infrared temperature sensor S1 for measuring the temperature of the semiconductor device 41 is attached to the mounting table 44. As shown in FIG.

The mounting table 44 is replaceable. Further, the contact pins 45 and the auxiliary terminals 47 can be replaced together with the plate-like member 48, and these can be replaced according to the semiconductor device 41 to measure the static characteristics, dynamic characteristics, etc. of various semiconductor devices 41. can be done.

The movable portion 49 is provided above the mounting portion 42 . The movable portion 49 can be vertically moved by a movable mechanism, contacts the upper surface of the package of the semiconductor device 41 to press the semiconductor device 41 from above, and raises the temperature of the semiconductor device 41 . The movable portion 49 has a pressing member 59 for pressing each terminal of the semiconductor device 41 against the contact pin 45 . When measuring the characteristics of the semiconductor device 41, first, the semiconductor device 41 is mounted on the mounting table 44, the movable portion 49 is moved downward, and the semiconductor device 41 is pressed from above. Then, each terminal of the semiconductor device 41 is pressed by the pressing member 59 to connect each terminal to the measurement circuit 46 via the contact pin 45 . In this state, the semiconductor device 41 is heated by the heat source section 51 installed above the movable section 49, and the static characteristics, dynamic characteristics, etc. of the semiconductor device 41 are measured. When the measurement of the semiconductor device 41 is completed, the heating is stopped, the movable portion 49 is moved upward, and the semiconductor device 41 is unloaded.

5 is a side view showing the configuration of the movable part and the heat source part of the test apparatus shown in FIG. 4. FIG. The heat source 51 has a heat sink 52 in the center in the vertical direction and a cooling fan 53 above the heat sink 52. The heat sink 52 and the cooling fan 53 suppress an abnormal temperature rise of the heat source 51. be done.

The heat source unit 51 also includes straight-tube halogen lamps 54 arranged in parallel below the heat sink 52 , and the infrared rays emitted from the halogen lamps 54 raise the temperature of the semiconductor device 41 . Each halogen lamp 54 also has a reflector 55 . The reflector 55 is formed by a parabolic mirror that emits infrared rays toward the movable portion 49 side, and the halogen lamp 54 is arranged at the focal point of the paraboloid. Such an arrangement allows the heat source section 51 to radiate infrared rays substantially parallel to the movable section 49 . In addition, since the halogen lamps 54 are arranged in parallel, it is possible to irradiate the infrared rays substantially parallel over a wide range as indicated by the arrows. Even if the movable part 49 is moved with respect to the fixed heat source part 51 by the parallel irradiation of the infrared rays, the temperature distribution of the infrared rays incident on the heat-conducting member 58, which will be described later, hardly changes. Static characteristics and dynamic characteristics of the semiconductor device 41 can be measured with few fluctuation factors.

The heat source unit 51 can irradiate an area larger than the semiconductor device 41 when viewed from above with infrared rays, and can raise the temperature of the semiconductor device 41 to a set temperature. number is set.

The halogen lamp 54 and the reflector 55 are housed inside a case 56 that is open on the infrared radiation side. With such a configuration, leakage of infrared rays is prevented, and thermal efficiency is improved. The test apparatus 40 further includes a heat sink 52 on top of this case 56 .

The light collecting dome 57 is provided so as to cover the case 56 from below, reflects the infrared rays from the heat source section 51 and collects them on the heat conducting member 58 . Further, the plate-like heat conducting member 58 is provided at a position facing the semiconductor device 41 on the lower side of the condensing dome 57 . The heat-conducting member 58 is directly irradiated with the infrared rays from the heat source section 51 and is heated. Further, due to the downward movement by the movable portion 49 , the heat conducting member 58 comes into contact with the upper surface of the semiconductor device 41 to raise the temperature of the semiconductor device 41 .

Some semiconductor devices 41 have electrodes exposed from the upper surface of the package in order to improve heat dissipation. If a conductive heat-conducting member such as metal is brought into contact with the semiconductor device 41 whose electrodes are exposed, the semiconductor device 41 may be damaged, or the characteristics of the semiconductor device 41 may not be measured correctly.

In preparation for such a case, the heat-conducting member 58 is preferably an insulator capable of efficiently raising the temperature of the semiconductor device 41 by infrared irradiation, that is, the substrate of the present disclosure.

The heat conducting member 58 is appropriately designed according to the shape and size of the upper end surface of the semiconductor device 41 . By designing in this way, the test apparatus 40 can reduce loss associated with heat conduction from the heat conducting member 58 and efficiently raise the temperature of the semiconductor device 41 .

The test apparatus 40 having the substrate of the present disclosure as the heat-conducting member 58 can correctly measure the characteristics of the semiconductor device 41 without damaging the semiconductor device 41 .

Although the embodiments according to the present disclosure have been exemplified above, it goes without saying that the present disclosure is not limited to the above-described embodiments, and can be arbitrarily adopted as long as they do not deviate from the gist of the present disclosure.

For example, in the above-described embodiments, the substrates are used for vehicle-mounted optical equipment and test equipment, but the substrates of the present embodiment are not limited to vehicle-mounted optical equipment and test equipment. , can also be used for other purposes. Other uses include, for example, electronic equipment, medical/physical and chemical equipment, and the like. Specific examples include medical equipment such as CT scans, and analytical devices such as transmission electron microscopes (TEMs). In addition, the application of the substrate is not limited to the examples.

EXAMPLES The present disclosure will be described in detail below with reference to examples, but the present disclosure is not limited to the following examples.

First, powders of aluminum oxide, silicon oxide, calcium carbonate, magnesium hydroxide and titanium oxide were prepared.

The contents of the powders of aluminum oxide, silicon oxide, calcium carbonate, magnesium hydroxide and titanium oxide were adjusted so that the components constituting the sintered body as the substrate had the values shown in Table 1.

Then, these powders were wet-mixed and pulverized in a barrel mill to obtain a slurry. In the pulverization, the solvent, 1.25 parts by mass of polyvinyl alcohol (PVA) with respect to 100 parts by mass of the solvent, and 0.3 parts by mass of a dispersant with respect to 100 parts by mass of the solvent were also put into the grinder. . Next, the resulting slurry is demagnetized so that the total content of Fe, Ni, Co, Mn and Cr in the substrate is adjusted to the value shown in Table 1, and then spray-dried to obtain granules. Obtained. The stainless steel member used for the crusher was previously coated with a TiN film, and then the powder was crushed.

Then, the granules were molded by cold isostatic pressing (CIP) and then subjected to cutting to obtain a molded body. After that, the obtained molded body was held at a temperature of 1570° C. in an air (oxidizing) atmosphere for 2 hours to obtain a sintered body. Next, the surface of the sintered body was polished using a vibration barrel polishing machine.

Then, the sintered body obtained by the above method is held at a temperature of 1350° C. for 1 hour and 30 minutes in a reducing atmosphere (mixed gas with a nitrogen:hydrogen ratio of 88.5% by volume:11.5% by volume). Therefore, sample no. 1-4 were obtained.

Each sample obtained was identified using XRD. The value of x in TiO _2-x was obtained using a transmission electron microscope (TEM). Also, the contents of the elements constituting each sample were determined using XRF, and converted into the identified components. Furthermore, the contents of Fe, Ni, Co, Mn and Cr, which are minor components, were determined using a glow discharge mass spectrometer (GDMS). These results are shown in Table 1. Each sample contains unavoidable impurities as components not shown in Table 1.

In addition, for each sample, the reflectance in the region of wavelengths from 250 nm to 2500 nm is obtained using an ultraviolet-visible-near-infrared spectrophotometer (manufactured by JASCO Corporation, V-670), and the measured values are shown as a graph. 6. Also, ΔR was calculated from the minimum value Rmin and the maximum value Rmax of the reflectance in the above region of each sample. Table 1 shows the minimum value Rmin, maximum value Rmax and ΔR of the reflectance.

Here, the integrating sphere unit used for measuring the reflectance is ISN-723, the reference light source is a deuterium lamp for a wavelength range of 250 nm to 360 nm, and a halogen lamp for a wavelength range of 360 nm to 2500 nm. The mode was total reflectance, the data acquisition interval was 1.0 nm, the UV/Vis bandwidth was 5.0 nm, and the NIR bandwidth was 20.0 nm.

As shown in Table 1 and FIG. 1 to 3 are sample Nos. Rmax and ΔR values were smaller than 4. From this result, it was found that the composition formula is TiO _2-x (1≦x<2), and the total content of Fe, Ni, Co, Mn and Cr is 260. It was found that if the weight is ppm or less, the reflectance is low in the wavelength range of 250 nm to 2500 nm, and the variation in the wavelength distribution of the light intensity of the reflected light with respect to the irradiation light is small.

In particular, sample no. 1 has a reflectance difference ΔR of 6.2% in the above regions, so it is more suitable for the use as described above.

For each sample, the volume resistivity at room temperature (20°C) was determined according to JIS C 2141:1992. The measurement results are as follows.
Sample no. 1:10 ^11Ω・m
Sample no. 2:10 ^12Ω・m
Sample no. 3:10 ^12Ω・m
Sample no. 4:10 ^10Ω・m

Although the sum of the components shown in Table 1 for each sample is not 100% by mass, components other than those shown in Table 1 are unavoidable impurities.

20 lamp device 21 translucent cover 22 housing 23 lamp chamber 24 headlamp 25 first sensor module 251 first substrate 252 first visible light camera 253 first LiDAR sensor 253a light emitting portion 253b light receiving portion 254 first light shielding member 255 control portion 256 Communication unit 257 Power supply unit 258 First actuator 26 Second sensor module 261 Second substrate 262 Second visible light camera 263 Second LiDAR sensor 264 Millimeter wave radar 265 Second light shielding member 266 Second actuator 27 Signal processing unit 271 First drive signal 272 second drive signal 30 head-up display 31 in-vehicle projector module 32 reflection mirror 33 microlens array 34 convex lens 35 combiner 36 lens holding member 40 testing apparatus 41 semiconductor device 42 mounting section 43 coil spring 44 mounting table 45 contact pin 46 measuring circuit 47 Auxiliary terminal 48 Plate-like member 49 Movable part 51 Heat source part 52 Heat sink 53 Cooling fan 54 Halogen lamp 55 Reflector 56 Case 57 Condensing dome 58 Heat conducting member 59 Pressing member

Claims (3)

The content of aluminum oxide converted to Al ₂ O ₃ is 90% by mass or more, and the composition formula includes titanium oxide represented by TiO _2-x (1 ≤ x < 2), Fe, Ni, The total content of Co, Mn and Cr is 86 mass ppm or more and 260 mass ppm or less ,
TiO _2-x is 1.5% by mass or more and 1.7% by mass or less,
The maximum value Rmax of the reflectance of the region at a wavelength of 250 nm to 2500 nm is 14.56% or more and 22.44% or less,
A substrate made of an aluminum oxide-based ceramic having a difference ΔR between a maximum value Rmax and a minimum value Rmin of reflectance in a region having a wavelength of 250 nm to 2500 nm of 6.18% or more and 13.68% or less . 2. The substrate according to claim 1, which is used for in-vehicle optical equipment. The substrate according to claim 1, which is for test equipment.

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