JP2001221729A - Apparatus for inspecting quality for board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for inspecting a quality for board, enabling highly reliable inspection of an entire checking area for quality. SOLUTION: A bending stress is imposed on a thin 1 and a tensile stress produced by bending is allowed to reach a predetermined allowable stress to determine whether or not the 1 is defective. The apparatus includes a pressure contact stand 2 having a mounting surface on which one side of the board 1 is placed in contact therewith, and having a recessed portion 2 formed in an area corresponding to the board checking range of the mounting surface, for producing the allowable stress while the board is pressed into contact therewith, and a pressing means 3 for pressing the other side of the base 1 placed on the pressure contact stand 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a board quality inspection apparatus for applying bending stress to a thin-plate board to allow a tensile stress generated by bending to reach a predetermined allowable stress to determine the quality of the board.

[0002]

2. Description of the Related Art As a conventional quality inspection apparatus of this kind, for example, a three-point bending apparatus applied to ceramics is known. FIG. 15 is a schematic configuration diagram of the three-point bending apparatus, in which a pair of support bases 20 arranged in parallel at a predetermined interval.
A ceramic substrate 22 is placed on the upper surface, and a load is applied by a pressing jig 21 from above a central portion of the pair of support bases 20 to generate a bending stress. The configuration is such that a pressing force P that reaches a predetermined allowable stress is applied.

[0003]

By analyzing the stress distribution of the ceramic substrate 22 inspected by the above-mentioned conventional quality inspection apparatus by the finite element method, as shown in the diagram of FIG. A diagram showing the relationship between the arrangement direction position and the bending stress is obtained. In this case, assuming that the pressing position by the pressing jig 21 is point A, the supporting position by one supporting stand 20 is B1 point, and the supporting position by the other supporting stand 20 is B2 point, the bending stress is immediately before point A from point B1. The stress increases linearly up to the allowable stress within a narrow range around the point A, and decreases linearly from the point immediately after the point A to the point B2.

Accordingly, the area where the allowable stress is generated by the three-point bending apparatus is limited to the vicinity of the point A, and the other area is less than the allowable stress, and it is not determined whether the endurable stress can be tolerated. You can see that.

[0005] As is well known, the quality of a ceramic substrate or the like used as a substrate on which electric components are mounted may vary in manufacturing. As a result of quality inspection performed by partially generating allowable stress using a three-point bending device, defects are present in other parts even if it is determined to be a non-defective product. In some cases, the ceramic substrate and the like were damaged.

However, there has been a problem that the conventional three-point bending apparatus cannot perform a sufficient quality evaluation and lowers the reliability of the substrate.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems of the conventional apparatus, and to provide a board quality inspection apparatus capable of performing highly reliable quality inspection over the entire quality discrimination area. is there.

[0008]

The invention according to claim 1 is
In a board quality inspection apparatus that applies bending stress to a thin plate-shaped board and makes the tensile stress generated by bending reach a predetermined allowable stress to determine the quality of the board, the board is placed in contact with one surface of the board. A mounting surface having a mounting surface, a pressing portion having a concave portion for generating an allowable stress in a state where the substrate is pressed against the region corresponding to the pass / fail determination range of the substrate on the mounting surface, and mounted on the pressing surface. Pressing means for pressing the other surface of the substrate.

According to a second aspect of the present invention, in the substrate quality inspecting apparatus according to the first aspect, the concave portion of the pressing table has a cylindrical surface having a uniform curvature.

According to a third aspect of the present invention, in the substrate quality inspection apparatus according to the first aspect, the concave portion of the press-contact table has a spherical surface having a uniform curvature.

According to a fourth aspect of the present invention, in the apparatus for inspecting quality of a substrate according to any one of the first to third aspects, the pressing means is fitted with substantially the same curvature as the concave part. Characterized in that it is a pressing die having:

According to a fifth aspect of the present invention, in the substrate quality inspection apparatus according to the fourth aspect, the pressing die is pressed using the pressure of the fluid.

According to a sixth aspect of the present invention, there is provided the board quality inspection apparatus according to the fourth or fifth aspect, wherein sliding friction is provided between the bottom surface of the concave portion of the press-contacting table and the substrate and between the pressing die and the substrate. The bearing is characterized in that a bearing for reducing the pressure is interposed.

According to a seventh aspect of the present invention, in the substrate quality inspection apparatus according to any one of the first to third aspects, the pressing means is a pressurized fluid.

The invention according to claim 8 is a substrate for determining whether the substrate is good or bad by applying a bending stress to a thin plate-like substrate having a square planar shape and causing a tensile stress generated by the bending to reach a predetermined allowable stress. In a quality inspection device, a first support member that supports a pair of diagonal vertices of a substrate so as to be pressurizable in a front direction of a substrate surface, and a pair of diagonal vertices of a substrate that is formed on a substrate surface. A second support member for supporting the pressurizable member in the back direction of the second member, and moving means for moving at least one of the first and second support members in a direction in which the first support member and the second support member can be pressurized by a dimension that causes an allowable stress. It is characterized by having.

According to a ninth aspect of the present invention, there is provided a board quality inspection apparatus for determining the quality of a board by applying a bending stress to a thin board and causing a tensile stress generated by the bending to reach a predetermined allowable stress. Two plate members which are respectively disposed on both sides of the substrate and have different linear expansion coefficients from each other;
It is characterized by comprising a holding means for holding the two plate members in close contact with the substrate and a heating means for heating the two base plate members to a temperature at which an allowable stress is generated.

According to a tenth aspect of the present invention, in the substrate quality inspection apparatus according to the ninth aspect, the heating means comprises
It is an electric furnace for heating a plate material in the same atmosphere.

According to an eleventh aspect of the present invention, in the substrate quality inspection apparatus according to the ninth aspect, the heating means is a heater incorporated in each of the two plate members.

According to a twelfth aspect of the present invention, there is provided a board quality inspection apparatus for determining the quality of a board by applying a bending stress to a thin board and causing a tensile stress generated by the bending to reach a predetermined allowable stress. The two plate members, which are disposed opposite to each other on both surfaces of the substrate and have different linear expansion coefficients, and the two plate members are wound in close contact with the substrate, and
A belt-shaped heater for heating to a temperature at which an allowable stress is generated.

According to a thirteenth aspect of the present invention, there is provided a board quality inspection apparatus for determining the quality of a board by applying a bending stress to a thin board and causing a tensile stress generated by the bending to reach a predetermined allowable stress. Free-support means for freely supporting the substrate, and an ultrasonic transmitter for applying ultrasonic waves to the freely-supported substrate and resonating and vibrating to a size that generates allowable stress. .

According to a fourteenth aspect of the present invention, there is provided a board quality inspection apparatus for applying a bending stress to a thin plate-shaped substrate to cause a tensile stress generated by bending to reach a predetermined allowable stress to determine the quality of the substrate. A condensing lamp for irradiating one surface of the substrate with heat rays, a fan for cooling the other surface of the substrate, and a control unit for controlling at least the output of the condensing lamp and the condensing lamp among the fans to generate an allowable stress; ,
It is characterized by having.

According to a fifteenth aspect of the present invention, a bending stress is applied to a thin plate-shaped substrate having a conductive layer attached to at least one surface of a ceramic, and a tensile stress generated by bending reaches a predetermined allowable stress. A board quality inspection device for judging pass / fail of the substrate, comprising: a power supply device for supplying a current between end portions of the conductive layer on one side separated from each other; and a current control unit for controlling a supplied current to generate an allowable stress. It is characterized by the following.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on preferred embodiments shown in the drawings.

FIG. 1 is a schematic configuration diagram of a first embodiment of a board quality inspection apparatus according to the present invention. For example, a pressure contact table 2 on which a substrate 1 made of ceramic is mounted and a pressure contact table 2 from above. A pressing die 3 for pressing the substrate 1 and the pressing die 3
And pressurizing means (not shown) which applies a load P in the direction of the arrow, such as a press. Among these, a concave portion 2b having a cylindrical surface 2a having a uniform curvature over a region substantially equal to or larger than the planar shape of the substrate 1 is formed on the press contact table 2, and the pressing die 3 A convex portion 3b having substantially the same planar shape and having a cylindrical surface 3a having a uniform curvature is formed at the lower end so as to fit with the concave portion 2b of the press-contacting table 2.
The curvature of the concave portion 2b and the convex portion 3b is such that when the pressing die 3 is pressed against the pressure welding table 2 by the load P and the substrate 1 is sandwiched without any gap, the tensile stress of the surface portion in contact with the cylindrical surface 2a of the pressure welding table 2 is determined. It is a value that reaches the allowable stress. That is,
The cylindrical surface 3a has a smaller curvature radius than the cylindrical surface 2a by the thickness of the substrate 1. This curvature can be determined by material mechanics calculations or by multiple experiments.

Incidentally, the ratio of the vertical or horizontal dimension to the thickness is 8
The above substrate, for example, a thickness of 1 mm and a width of 40 m
m, when inspecting a ceramic substrate with a length of 40 mm,
The curvature ρ of the cylindrical surface of the concave portion 2b of the press-contacting table 2 can be determined by the theoretical bending equation of a beam shown in the following equation.

1 / ρ = M / E · I (1) where M: moment E: modulus of longitudinal elasticity I: second moment of area

Here, the allowable stress is set to 20 kgf / mm ²
When the radius of curvature is about 800 mm,
The substrate 1 is placed on the press-contact table 2 having a cylindrical surface 2a having a radius of curvature of 800 mm.
Is pressed with a uniform pressure, so that an allowable stress can be generated in the substrate 1.

As described above, by using the pressing table 2 and the pressing die 3 having a plane shape substantially equal to or wider than the substrate 1, an allowable stress can be generated in the entire substrate 1. , The quality of the substrate can be inspected with high reliability.

In the first embodiment shown in FIG. 1, the entire substrate 1 is inspected. However, there are cases where a part of the substrate 1 is inspected or a plurality of portions of the substrate 1 are inspected. possible. FIG. 2 is a schematic configuration diagram of a second embodiment that satisfies this requirement. In accordance with a pass / fail determination range X of the substrate 1, a concave portion 2c is formed on the press-contact table 2A, and a convex portion 3c is formed on the pressing die 3A.
Are formed locally, and each has a cylindrical surface having exactly the same curvature as that described with reference to FIG.

According to this embodiment, since an allowable stress can be generated at a desired portion of the substrate, a reliable quality inspection and a highly reliable quality inspection of the pass / fail determination area can be performed.

In each of the above-described embodiments, since a bending stress is generated in the substrate 1 along the cylindrical pressure contact surface, only a directional test result is obtained, and both vertical and horizontal test results are required. In this case, the substrate 1 is rotated by 90 degrees on the press-contacting table 2 or 2A, and two inspections have to be performed.

FIG. 3 is a schematic configuration diagram of a third embodiment of a board quality inspection apparatus which enables such a plurality of inspection steps to be performed only once. In this embodiment, a pressing table 4 having a concave portion 4b having a spherical bottom 4a in a region where the substrate 1 is placed, a pressing die 5 formed of a sphere, and a load P in the direction of the pressing table 4 holding the pressing die 5 are provided. And a pressurizing means (not shown) such as a press for applying the pressure. In this case, in order to facilitate understanding, the concave portion 4b of the press-contacting base 4 is extremely deeply hollowed out, and the pressing die 5 is also shown as a complete sphere. The bottom is the substrate 1
Is a spherical surface having a uniform curvature so as to generate an allowable stress when pressed against each other, and the pressing die 5 has a convex portion facing the pressing base 4 with a radius of curvature corresponding to the thickness of the substrate 1 with respect to the bottom of the pressing base 4. It is sufficient if the spherical surface is small.

Although the plane shape of the concave portion 4b of the press-contact table 4 is slightly smaller than the plane shape of the substrate 1,
By forming the concave portion 4b having a diameter larger than the diagonal dimension of the substrate 1, quality inspection over the entire surface of the substrate 1 becomes possible. Further, the size of the concave portion 4b can be arbitrarily determined so as to correspond to the pass / fail judgment area.

Thus, according to the third embodiment shown in FIG. 3, it is possible to perform a reliable quality inspection over the entire pass / fail determination area in one inspection step without making the directionality a problem. A highly reliable quality inspection of the substrate can be performed.

FIG. 4 is a schematic configuration diagram of a fourth embodiment of the substrate quality inspection apparatus according to the present invention. In the figure, the same elements as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In this embodiment, a cylindrical bottom 2a of a pressure welding table 2 and a pressing die 3
A plurality of bearings are distributed and arranged at substantially equal intervals on the convex portion 3b formed of a cylindrical surface, thereby eliminating deformation loss due to friction between the substrate 1 and the press-contacting base 2 and the pressing die 3, thereby eliminating the entire quality judgment area. , A more uniform allowable stress can be generated, and the reliability can be further improved.

It is to be noted that the method of inserting a bearing between the substrate 1 and the press-contacting stand and press die for pressing the substrate 1 is not limited to the first embodiment shown in FIG. 1, but is shown in FIG. 2 or FIG. It is needless to say that the present invention can be applied to the embodiment.

By the way, the pressing means constituting each of the above-described embodiments can be a mechanical pressing structure such as a manual or electric motor drive, or a pressing structure using a fluid pressure using a piston or the like. Of these, the former may involve an impact, so from the viewpoint of improving the inspection accuracy, it is considered that the pressing structure by the fluid pressure is optimal.

On the other hand, in each of the above-described embodiments, the substrate 1 is pressed against the bottom surface of the concave portion of the pressing table by using a pressing die. However, instead of the pressing die, an elastic member such as rubber capable of applying an evenly distributed load is used. Or by pressing the concave portion of the press table to a vacuum and pressurizing the surface of the substrate 1 with a fluid to press the substrate 1 against the bottom surface of the concave portion of the press table, thereby affecting the mechanical accuracy of the pressing die. Quality inspection can be performed with an even stress distribution without any problems.

FIG. 5 is an explanatory view of the configuration of a fifth embodiment of the board quality inspection apparatus according to the present invention. In this embodiment, a substrate 6 having a square planar shape is to be inspected.
The first support members 9A and 9 that support a set of diagonal vertices in the front direction of the substrate surface, that is, above the drawing so as to be pressurized
A, second support members 9B, 9B for supporting another pair of diagonal vertexes of the substrate 6 in the direction opposite to the substrate surface, that is, in the downward direction in the drawing, and the first support member. 9A, 9A and at least one of the second support members 9B, 9B, for example, the support means 9A, 9A are moved in a direction in which pressurization is possible.
And a moving means 8A that bends in a saddle shape and moves by a dimension that causes the allowable stress.

With such a configuration, the substrate 6 having a square planar shape can be treated as a beam having equal strength in terms of material mechanics, so that a uniform allowable stress can be generated over a wide range of the substrate. At the same time as the pass / fail determination is performed over the entirety, a highly reliable board quality inspection can be performed.

FIG. 6 is an explanatory view of the configuration of a sixth embodiment of the board quality inspection apparatus according to the present invention. In this embodiment, a plate member 10 made of a material having a linear expansion coefficient α1 and a plate member 11 made of a material having a linear expansion coefficient α2 having a different value are prepared, and these plate members 10 and 11 are sandwiched at, for example, a plurality of positions. The substrate is brought into close contact with the substrate by means of the holding means 8B to form a bimetal structure. The structure integrated by the holding means 8B is housed in an electric furnace at a predetermined temperature, and the substrate 1 is bent to generate allowable stress to judge pass / fail. Are shown. In this case, the linear expansion coefficients α of the plate materials 10 and 11
The furnace temperature at which an allowable stress is generated on the substrate can be determined by calculation or experiment from 1, α2.

According to this configuration, as in the above-described embodiment, a reliable quality inspection can be performed over the entire pass / fail determination area, and a highly reliable substrate quality inspection can be performed.

FIG. 7 is an explanatory view of the configuration of a seventh embodiment of the substrate quality inspection apparatus according to the present invention. In the drawing, components denoted by the same reference numerals as those in the embodiment shown in FIG. 6 indicate the same components. In this embodiment, for example, a plurality of resistance wires are insulated and formed in a strip shape, and a heater 12 generally called a band heater is attached to each of the outsides of the plate members 10 and 11 sandwiching the substrate 1. By passing a predetermined current through the heater 12, an allowable stress is generated in the substrate 1 to judge the quality. Instead of the band heater, a heater generally called a rod-shaped heater having an overall shape of a rod may be used. When this rod-shaped heater is used, a hole is formed in the longitudinal direction of the plate members 10 and 11, and the rod-shaped heater is inserted into this hole.

As described above, by incorporating the heaters in the plate members 10 and 11, it is possible to perform a reliable and reliable board quality inspection over the entire pass / fail determination area with a simpler configuration than using an electric furnace. Will be possible.

FIG. 8 is a schematic configuration diagram of an eighth embodiment of the board quality inspection apparatus according to the present invention. In this embodiment, as shown in FIG. 6 or FIG. 7, a plate 10 made of a material having a linear expansion coefficient α1 and a linear expansion coefficient
The sheet material 11 made of the material 2 is superimposed on the front surface and the back surface of the substrate 1, respectively, and a band heater is wound therearound.
A quality inspection device is configured as 2A. Then, by passing a predetermined current through the heater 12A, the substrate 1 is bent at the same time as the plates 10 and 11 to generate an allowable stress. Thus, according to the eighth embodiment, the heater 1
Since the function of the holding means is provided to the 2A, it is possible to perform a reliable and reliable board quality inspection over the entire pass / fail determination area with a simpler configuration than the embodiment shown in FIG. .

FIG. 9 is an explanatory view of the configuration of a ninth embodiment of the board quality inspection apparatus according to the present invention. In this embodiment, the substrate 1 is suspended at a plurality of positions by using a thread 14 as a free supporting means, and the restraining condition for the substrate 1 is substantially removed, that is, in a so-called free supporting state, while the side portion or the plate surface The ultrasonic transmitter 13A is arranged at a position facing the.
The control means 13B generates a half-wave standing wave vibration on the substrate 1 by the ultrasonic wave generated from the ultrasonic wave transmitter 13 and increases the ultrasonic output to a predetermined magnitude to generate an allowable stress on the substrate 1. And According to this configuration, in addition to the extremely simple configuration, a reliable and reliable quality inspection can be performed over the entire pass / fail determination area, and the bending direction of the substrate is changed in some cases because the substrate is bent on both sides. There is also an advantage that even if two different test results are requested, only one test is required.

FIG. 10 is a schematic configuration diagram of a substrate quality inspection apparatus according to a tenth embodiment of the present invention. Here, a fan 15 is arranged on one surface of the substrate 1 to face it, and a condenser lamp 16A for irradiating infrared rays is arranged on the other surface of the substrate 1 and its output is controlled by the control means 16B. Thereby, the fan 15 cools one surface of the substrate 1 and the condenser lamp 16A heats the other surface of the substrate 1. As a result, thermal deformation due to the temperature gradient, that is, bending occurs, and an allowable stress can be generated in the other surface portion. According to this configuration, there is an advantage that the inspection over the entire pass / fail determination area can be executed substantially without contact with others.

In the above embodiment, only the output of the condenser lamp 16A is controlled. However, only the output of the fan 15 may be controlled, or both of them may be controlled simultaneously.

Incidentally, the above-mentioned substrate 1 was intended to be inspected with only a ceramic layer, but the present invention is not limited to this application. For example, as shown in FIG. The present invention can also be applied to an insulating substrate in which the first conductive layer 17A is joined to one surface and the second conductive layer 17B is joined to the other surface.

FIG. 12 is a schematic structural view of an eleventh embodiment of a board quality inspection apparatus for inspecting the board shown in FIG. 11 in particular. Here, the fan 15 is disposed to face the side to which the first conductive layer 17A is bonded, while the second conductive layer 17B bonded to the opposite surface is used as a resistance heating element at both ends thereof.
A power supply 1 is connected via a variable resistor VR as current control means.
9 is connected. Thus, as shown in FIG.
Thermal deformation due to the temperature gradient, that is, bending can be caused to generate allowable stress on the other surface portion.

FIG. 13 shows another example of the structure of the substrate to be inspected. The ceramic layers are stacked in two layers with the conductive layer 17 interposed therebetween, and the conductive layers 17 are also provided on both outer surfaces.
Are joined.

FIG. 14 shows a structure in which three ceramic layers are stacked with the conductive layer 17 interposed therebetween, and the conductive layers 17 are joined to both outer surfaces. According to each of the above-described embodiments, even with these substrates, quality inspection can be performed in exactly the same manner as with a substrate including only a ceramic layer.

Although not shown, FIG. 12 or FIG.
In the substrate structure shown in FIG. 3, even if one of the conductive layers formed on both outer surfaces is removed, or instead of ceramic, fiber reinforced plastic (FRP), fiber reinforced metal (FRM), fiber reinforced Even for a composite material such as ceramic (FRC), quality inspection can be performed in exactly the same manner as a substrate made of only a ceramic layer.

Further, quality inspection can be performed in the same manner even for a laminate of ceramic and metal.

[0055]

As is apparent from the above description, according to the present invention, it is possible to provide a board quality inspection apparatus which enables highly reliable quality inspection over the entire quality discrimination area.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a first embodiment of a board quality inspection apparatus according to the present invention.

FIG. 2 is a schematic configuration diagram of a second embodiment of the board quality inspection apparatus according to the present invention.

FIG. 3 is a schematic configuration diagram of a third embodiment of the board quality inspection apparatus according to the present invention.

FIG. 4 is a schematic configuration diagram of a fourth embodiment of the board quality inspection apparatus according to the present invention.

FIG. 5 is a configuration explanatory view of a fifth embodiment of the board quality inspection apparatus according to the present invention.

FIG. 6 is a configuration explanatory view of a sixth embodiment of the board quality inspection apparatus according to the present invention.

FIG. 7 is a configuration explanatory view of a seventh embodiment of the board quality inspection apparatus according to the present invention.

FIG. 8 is a schematic configuration diagram of an eighth embodiment of the board quality inspection apparatus according to the present invention.

FIG. 9 is a configuration explanatory view of a ninth embodiment of a board quality inspection apparatus according to the present invention.

FIG. 10 is a schematic configuration diagram of a substrate quality inspection apparatus according to a tenth embodiment of the present invention.

FIG. 11 is a configuration explanatory view of another inspection object of the board quality inspection apparatus according to the present invention.

FIG. 12 is a schematic configuration diagram of an eleventh embodiment of a substrate quality inspection apparatus for inspecting the substrate shown in FIG. 11;

FIG. 13 is a side view showing another configuration example of the substrate as the inspection target.

FIG. 14 is a side view showing another example of the configuration of the substrate to be inspected.

FIG. 15 is a schematic configuration diagram of a three-point bending device shown as a conventional quality inspection device.

FIG. 16 is a diagram showing the relationship between the placement direction position of the support and the bending stress obtained by analyzing the stress distribution of the substrate inspected by the three-point bending apparatus shown in FIG. 15 by the finite element method.

[Explanation of symbols]

 Reference Signs List 1, 6 Substrate 2, 4 Press-contact table 3, 5 Pressing die 7 Bearing 8A Moving means 8B Nipping means 9A, 9B Support member 10, 11 Plate 12 Heater 12A Strip heater 13 Ultrasonic transmitter 14 Thread 15 Fan 16 Condenser lamp 17, 17A, 17B Conductive layer 18 Ceramic layer 19 Power supply 20 Support base 21 Pushing jig 22 Ceramic substrate

Claims (15)

[Claims] An apparatus for inspecting quality of a substrate, wherein a bending stress is applied to a thin substrate and a tensile stress generated by the bending reaches a predetermined allowable stress to determine the quality of the substrate. It has a mounting surface to be placed in contact with, in an area corresponding to the pass / fail determination range of the substrate on the mounting surface,
A press-contact table in which a concave portion that generates the allowable stress in a state where the substrate is pressed is formed, and pressing means for pressing the other surface of the substrate placed on the press-contact table. Board quality inspection equipment. 2. The apparatus for inspecting quality of a substrate according to claim 1, wherein the concave portion of the press-contact table has a cylindrical surface having a uniform curvature. 3. The substrate quality inspection apparatus according to claim 1, wherein the concave portion of the press-contact table has a spherical surface having a uniform curvature. 4. The substrate according to claim 1, wherein said pressing means is a pressing die having a convex portion fitted with substantially the same curvature as said concave portion. Quality inspection equipment. 5. The substrate quality inspection apparatus according to claim 4, wherein the pressing die is pressed by using a pressure of a fluid. 6. A bearing for reducing sliding friction is interposed between the bottom surface of the concave portion of the press-contacting table and the substrate, and between the pressing die and the substrate, respectively. A substrate quality inspection apparatus according to claim 5. 7. The apparatus according to claim 1, wherein said pressing means is a pressurized fluid. 8. A board quality inspection apparatus for applying a bending stress to a thin plate-like substrate having a square planar shape and allowing a tensile stress generated by bending to reach a predetermined allowable stress to determine the quality of the board. A first support member for supporting a pair of diagonal apexes of the substrate so as to be pressurizable in a front direction of the substrate surface; And a moving means for moving at least one of the first and second support members in a direction in which the first support member and the second support member can be pressurized by a dimension that causes the allowable stress. A board quality inspection apparatus characterized by the following. 9. A board quality inspection apparatus for applying a bending stress to a thin plate-shaped substrate to cause a tensile stress generated by the bending to reach a predetermined allowable stress to determine the quality of the substrate. The two plate members, which are respectively opposed to each other and have different linear expansion coefficients, are sandwiched between the two plate members in close contact with the substrate, and the base two plate members generate the allowable stress. A heating means for heating the substrate to a temperature to be heated. 10. The apparatus for inspecting quality of a substrate according to claim 9, wherein said heating means is an electric furnace for heating said substrate and two plate members in the same atmosphere. 11. The substrate quality inspection apparatus according to claim 9, wherein said heating means is a heater built in each of said two plate members. 12. A board quality inspection apparatus for applying a bending stress to a thin plate-shaped substrate to cause a tensile stress generated by bending to reach a predetermined allowable stress to determine the quality of the substrate. Two plate members which are respectively opposed to each other and have different linear expansion coefficients, and a band-shaped heater which winds the two plate members in close contact with the substrate and heats them to a temperature at which the allowable stress is generated; A board quality inspection device, comprising: 13. A board quality inspection apparatus for applying a bending stress to a thin plate-shaped substrate to cause a tensile stress generated by bending to reach a predetermined allowable stress to determine the quality of the substrate, wherein the substrate is freely supported. A free-supporting means, and an ultrasonic transmitter for applying ultrasonic waves to the freely-supported substrate and causing resonance vibration at a magnitude that generates the allowable stress. . 14. A quality inspection apparatus for a board, wherein a bending stress is applied to a thin plate-shaped substrate, and a tensile stress generated by the bending reaches a predetermined allowable stress to determine the quality of the substrate. A condenser lamp for irradiating a heat ray, a fan for cooling the other surface of the substrate, and a control unit for controlling at least an output of the condenser lamp among the condenser lamp and the fan to generate the allowable stress. A board quality inspection device, comprising: 15. A judgment is made as to whether the substrate is good or bad by applying a bending stress to a thin plate-shaped substrate having a conductive layer adhered to at least one surface of a ceramic and causing a tensile stress generated by the bending to reach a predetermined allowable stress. A substrate quality inspection device, comprising: a power supply device for supplying a current between the mutually separated ends of the conductive layer on one side; and a current control unit for controlling a supply current to generate the allowable stress. Board quality inspection equipment.