JP2010249549A - X-ray diffraction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray diffraction method to analyze crystalline materials at an interface of bonded different materials, without destroying the interface. <P>SOLUTION: The X-ray diffraction method of identifying the crystalline materials existing at the bonding interface of the different materials includes the processes: a process for arranging a sample S, using as an analysis object surface, a region whose cross section is presented by a curve among the bonding interfaces of the different materials between an X-ray irradiation source 10 and a diffraction line detector 30; a process for irradiating X-rays 52 to the analysis object surface, in a tangential direction of the curve from the radiation source 10; and a process for detecting the diffraction lines 54, generated by irradiation of the X-rays 52 by the diffraction detector 30. By having the X-rays irradiated in the tangent direction of the analysis object surface, the diffraction lines can be detected, without fail, from the analysis object surface in a nondestructive state. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an X-ray diffraction method. In particular, the present invention relates to an X-ray diffraction method that can identify a crystalline substance at an interface of bonded dissimilar materials without destroying the interface.

  A hermetic seal is known as a configuration for sealing a lead of a semiconductor module to an eyelet. A more specific structural example of the hermetic seal is as shown in FIG. The semiconductor module 100 includes a disc-shaped eyelet 110 made of Kovar or Cu—W alloy, a semiconductor element 120 such as a light receiving element (PD) or a light emitting element (LD), a lead 130 connected to the semiconductor element 120, and a semiconductor element 120. And a lens 150 provided on the top of the cap 140. In order to form a hermetic seal, the lead 130 of the semiconductor element 120 is passed through the through hole 110 h formed in the eyelet 110. The lead 130 is also typically made of Kovar. A glass 160 such as borosilicate glass is filled between the inner peripheral surface of the through hole 110h and the outer peripheral surface of the lead 130 and sealed.

At this time, an oxide film such as iron oxide may be formed at the interface between the lead and the glass. If the presence of each oxide can be confirmed by distinguishing this type of oxide film, such as FeO, Fe ₂ O ₃ , Fe ₃ O _4, etc., the evaluation of the interface between the lead and the glass, for example, the adhesion between the lead and the glass is evaluated. It is expected to be an index for

  One method for identifying oxides at this interface is an X-ray diffraction method. Conventionally, when analyzing an interface between different materials closely adhered to each other by an X-ray diffraction method, the hermetic seal is broken, the lead and the glass are peeled off, and the peeled surface is irradiated with X-rays to diffract the diffraction line. This can be done by analyzing the above. For example, as a similar technique, Patent Document 1 discloses a sample adjustment method for analyzing an interface between a bonding pad and a bonding wire by an X-ray diffraction method. Specifically, the bonded fine metal wires are peeled off from the bonding pad by physical force, and the exposed peeled surface is intermittently irradiated with an Ar ion beam from the surface to the inside, and ion etching is performed sequentially. The observation surface is exposed.

JP 2008-122328 A

  However, the method of peeling the dissimilar materials to be bonded and exposing the interface as described above has the following problems.

  First, the peeling operation itself between different materials is complicated. In particular, it is not always easy to exfoliate a brittle material such as glass from a lead accurately without damaging the exfoliation surface. As a result of the cautiousness required for the peeling operation, the peeling operation becomes more complicated.

  Moreover, it is difficult to obtain a release surface having a stable property. For example, when the lead and the glass are peeled off, the oxide film is not always peeled off in a state of being in close contact with either the lead or the glass. In particular, the peeled portion may be different between a sample having good adhesion between the lead and the glass and a sample having poor adhesion, and it may be difficult to perform appropriate peeling at the interface to be analyzed. As a result, it may be difficult to perform accurate X-ray diffraction on the interface to be analyzed.

  The present invention has been made in view of the above circumstances, and one of its purposes is X-ray capable of analyzing a crystalline substance at the interface without destroying the interface of the bonded dissimilar materials. It is to provide a diffraction method.

  As a result of studying a non-destructive X-ray diffraction method for analyzing the bonding interface of different materials, the present inventors devised the X-ray irradiation direction to irradiate the sample, and if necessary, the sample Obtaining knowledge that the above-mentioned object can be achieved by devising the shape, the present invention has been completed.

The X-ray diffraction method of the present invention relates to an X-ray diffraction method for identifying a crystalline substance existing at a bonding interface of different materials, and includes the following steps.
A process in which a sample whose analysis target surface is a region whose cross section is represented by a curve in the bonding interface is disposed between the X-ray irradiation source and the diffraction ray detector.
A process of irradiating the analysis target surface with X-rays in the tangential direction of the curve from the irradiation source.
A process of detecting diffraction lines generated by the X-ray irradiation with the diffraction line detector.

  According to this configuration, by irradiating X-rays in the tangential direction of the curve formed by the analysis target surface, it is possible to accurately detect diffraction lines from the non-destructive analysis target surface. For this reason, it is not necessary to separate the dissimilar materials that are joined when the sample is manufactured, and the analysis result does not depend on the properties of the separation surface.

  Here, the region of the bonded interface whose cross section is represented by a curve is at least one of the bonded interfaces whose cross section is represented by a curve when the predetermined cross section is taken with respect to the bonded interface. It is a part. For example, when the joining interface is a part of a cylindrical surface, if the cross section intersecting the axis of the cylinder is taken with respect to the joining interface, the interface is represented by an arc in the cross section. In addition, when the bonding interface is a part of a spherical surface, the interface is represented by an arc in the cross section if an arbitrary cross section is taken at the bonding interface. Of course, the curve represented in the cross section of the joint interface is not limited to the arc that forms a part of a perfect circle, and may be another curve such as an arc that forms a part of an ellipse.

  In the X-ray diffraction method of the present invention, the sample is preferably a thin plate having the tangential direction as a thickness direction.

  According to this configuration, it is possible to increase the X-ray permeability with respect to the sample, and it is possible to use lower energy X-rays. Moreover, the generation | occurrence | production location of a scattered X-ray can be made small and it can suppress that the peak in an X-ray diffraction line chart is buried in a background.

  In the X-ray diffraction method of the present invention, the diffraction line detector is preferably a two-dimensional detector.

  According to this configuration, for a sample that does not become a complete concentric circle due to a discontinuous X-ray diffraction pattern (Debye ring) due to circumstances such as high orientation of the crystalline material or a small number of crystal grains. Also, the diffraction lines can be detected efficiently.

  In the X-ray diffraction method of the present invention, it is preferable that the curve is an arc and the thickness of the X-ray is less than the diameter of the arc.

  According to this configuration, by using X-rays with a narrow irradiation area, it is possible to accurately analyze the crystal information of the interface even when the thickness of the interface of the sample is small. The X-ray thickness refers to a dimension in the radial direction of the arc formed by the analysis target surface and in a direction perpendicular to the tangent line of the arc in the X-ray irradiated to the sample.

  The X-ray diffraction method of the present invention is a sample in which one of the dissimilar materials is a low transmission material having a low X-ray transmittance and the other is a high transmission material having a higher X-ray transmission than the low transmission material. It can be used for analysis.

  According to this configuration, since one of the different materials is a highly transmissive material, the diffraction lines generated from the interface can be detected with appropriate intensity. In addition, the interface position of the sample can be easily recognized from the difference in the X-ray transmittance between the two transparent materials.

  In the X-ray diffraction method of the present invention, when a sample is a joining member of the low-permeability material and the high-permeability material, the low-permeability material is an electronic component lead, and the high-permeability material is the lead. It is mentioned that it is glass sealed to the lead penetration part of an electronic component.

  According to this configuration, it is possible to identify a crystalline substance at the interface between the leads of various electronic components and the glass, and use the identification result for evaluating the adhesion between the leads and the glass.

  In the X-ray diffraction method of the present invention, when a low-transmission material is used as a lead of an electronic component, the X-ray is irradiated in a direction intersecting with the axial direction of the lead.

  When irradiating X-rays in a direction along the axial direction of the lead, a diffraction line from the end face of the lead may be detected. However, if X-rays are irradiated in a direction crossing the lead axial direction, the diffraction lines from the lead end face can be removed and the diffraction lines from the interface can be detected more accurately. Furthermore, by irradiating X-rays in a direction substantially orthogonal to the axial direction of the lead, the optical path of the X-rays passing through the sample can be shortened compared to irradiating X-rays non-orthogonally with the axial direction of the lead, X-ray diffraction can be performed with high transmittance.

  In the X-ray diffraction method of the present invention, the X-ray may be radiated light.

  According to this configuration, it is possible to irradiate the sample with high-energy X-rays even if the X-ray thickness is reduced.

  In the X-ray diffraction method of the present invention, it is mentioned that the crystalline substance is an oxide.

  According to this configuration, since the interface of the sample can be analyzed nondestructively, it is possible to identify the oxide present at this interface with higher sensitivity. In the method in which the dissimilar materials to be joined are peeled to expose the peeled surface, the oxidizable elements that existed at the interface before peeling become oxides by the exposure of the peeled surface, and can be distinguished from the oxides that existed at the interface before peeling However, according to the method of the present invention, such a problem does not occur.

  According to the X-ray diffraction method of the present invention, it is possible to identify a substance present at the interface without destroying the interface of the bonded dissimilar materials.

It is explanatory drawing which shows the X-ray-diffraction method which concerns on the Example of this invention. It is explanatory drawing which shows the shape of the sample in the Example of this invention, and the irradiation conditions of the X-ray with respect to a sample. It is an X-ray diffraction chart which shows the analysis result in an example. It is a schematic explanatory drawing which shows the outline | summary of a hermetic seal.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 and 2. The method of the present invention includes the steps of “sample arrangement”, “X-ray irradiation”, and “diffracted ray detection”. In implementing this method, as shown in FIG. 1, an X-ray diffraction apparatus including an X-ray irradiation source 10, a sample placement unit 20, and a diffraction line detector 30 is used.

[Sample arrangement]
In the X-ray diffraction method of the present invention, first, the sample S is placed in the sample setting unit 20 located between the X-ray irradiation source 10 and the diffraction ray detector 30. This sample S is a member having an interface Sb to which different materials are joined. The material of the sample S is not limited as long as it is a member made of a joined body of different materials. In particular, it is preferable that one of the dissimilar materials is a low transmission material Si having a low X-ray transmittance, and the other is a high transmission material So having a higher X-ray transmission than the low transmission material Si. If it is an interface between materials having a large difference in transmittance, it is easy to detect a diffraction line from the interface in a limited manner. These transmittances depend on the energy of the irradiated X-rays, the material of the sample, the thickness of the sample, etc., but for example, in the case of the highly transmissive material So, it should be 80% or more, and more than 90%. In the case of the permeable material Si, it may be 30% or less, further 20% or less. As will be described later, when the joint interface is represented by an arc in its cross section, analysis of a sample in which a highly permeable material is arranged on the outer peripheral side of the arc and a low permeable material is arranged on the inner peripheral side of the arc The method of the present invention can be preferably used.

  A specific example of the low-permeability material Si is a lead of an electronic component, and a specific example of the high-permeability material So is a hard glass that seals the lead in the lead penetration portion of the electronic component. More specifically, a lead made of Kovar and a hard glass made of borosilicate glass can be mentioned. In addition, a metal material is used as the low-permeability material Si, and a resin is used as the high-permeability material So.

  In addition, the interface Sb of the sample has a region whose cross section is represented by a curve as an analysis target surface. As a specific example, a substantially cylindrical surface, a spherical surface, or a region composed of a part of these surfaces is used as the analysis target surface. When the cross section of the analysis target surface is substantially composed of a circular arc, the X-ray 52 incident from the tangential direction of the circular arc passes through one dissimilar material (eg, hard glass So) located outside the circular arc. Reach the interface. Therefore, the X-ray irradiation location at the interface Sb is a location where the other dissimilar material (for example, lead Si) located inside the arc is covered with the one dissimilar material, and is compared with the interface Sb in the non-destructive state. X-ray diffraction can be performed. In general, if the diameter of the arc is large, the region where the X-rays 52 are irradiated to the interface Sb is widened. If the diameter of the arc is small, the region where the X-rays 52 are irradiated to the interface is narrowed.

  As shown in FIG. 2, the sample S is preferably in the form of a thin plate whose thickness direction is the tangential direction of the analysis target surface. For example, when the hermetic seal in which the outside of the lead Si is covered with the hard glass So is used as the sample S, the interface between the lead Si and the hard glass So is an analysis target surface constituted by a cylindrical surface. In this case, X-rays may be irradiated from the outside of the sample S as it is in the tangential direction of the cylindrical surface, but in this case, the optical path of the hard glass So that is transmitted before the X-rays reach the interface becomes long. Therefore, if the analysis target surface is a cylindrical surface, the sample S is processed into a thin plate shape including the axis (see FIG. 2). If the analysis target surface is a spherical surface, the sample S is processed into a thin plate shape including the center. (Not shown) It is possible to shorten the optical path of the hard glass So that is transmitted before the X-rays reach the interface Sb. As a result, the background in the X-ray diffraction chart can be reduced, and the peak of the substance to be analyzed can be revealed. The thickness of the thin sample S depends on the size of the X-ray 52 irradiated to the sample S and the diameter of the arc appearing in the cross section of the analysis target surface. And so on. As a processing method for obtaining a thin film-like sample, there are chemical methods such as etching in addition to mechanical processing such as cutting, grinding, and polishing.

[X-ray irradiation]
The X-rays 52 irradiated to the sample can be X-rays generated using an X-ray tube, such as CuKα rays, but high-energy X-rays can be used and the brightness is high. Synchrotron radiation that can easily reduce the X-ray size can be suitably used.

  Here, when the joining interface is represented by an arc in the cross section of the analysis target surface, the dimension in the radial direction of the arc and the direction perpendicular to the tangent of the analysis target surface in the X-ray irradiated to the sample S The thickness is the thickness of the X-ray, and the width in the direction perpendicular to the thickness in the X-ray cross section is the width.

  The thickness (height) of the X-ray 52 is preferably narrowed down. By reducing the thickness of the X-ray, it is possible to irradiate the X-ray as much as possible to the interface portion, so that the diffraction line from the interface can be specifically detected. For example, the height of the X-ray may be less than the diameter of the arc formed by the analysis target surface, more specifically, less than 200 μm, 100 μm or less, and further 30 μm or less. However, the thickness of the X-ray is preferably adjusted according to the thickness of the interface portion in the sample.

  On the other hand, the width of the X-ray 52 is not particularly limited, but if it is unnecessarily large, it may be difficult to analyze a limited portion of the sample, so that it can be appropriately adjusted according to the shape and size of the sample. desirable.

  In this way, the size of the X-ray 52 can be easily reduced by disposing the slit 15 that transmits the X-ray 52 only in a specific range before the sample S.

  Such X-rays 52 irradiate the sample S from the tangential direction of the arc appearing in the cross section of the analysis target surface. By irradiating the sample S with X-rays 52 from such a direction, the interface portion of the sample S can be analyzed by X-ray diffraction in a non-destructive manner. The cutting direction for forming the cross section of the analysis target surface is not particularly limited as long as the interface appears in an arc shape. For example, when the analysis target surface is constituted by a part of a cylindrical surface, taking a cross section of the cylinder may be mentioned. Further, when the analysis target surface is constituted by a part of a spherical surface, it is possible to take an arbitrary cross section of the sphere, particularly a cross section passing through the center.

  The tangential direction of the arc may be a tangent other than a tangent parallel to the axial direction of the cylinder when the analysis target surface is a part of the cylindrical surface, and the analysis target surface is a part of the spherical surface. If configured, any tangent can be selected.

  In particular, when the analysis target surface is formed of a part of a cylindrical surface, it is preferable to irradiate the X-ray 52 at an angle close to a right angle with the axial direction of the cylinder. By irradiating X-rays 52 in a tangential direction at an angle close to a right angle with this axial direction, one optical path of a dissimilar material transmitted until the X-rays 52 reach the interface can be shortened, and the interface irradiated with X-rays The area can be narrowed down. In addition, by irradiating the end face side of the cylinder in the sample with X-rays, it is possible to avoid detecting diffraction lines from the end face. However, as long as the tangential direction intersects the axial direction of the cylindrical surface, X-rays do not necessarily have to be irradiated from the direction orthogonal to the axial direction of the cylindrical surface. For example, X-rays may be irradiated from a tangential direction inclined about ± 15 ° with respect to a direction orthogonal to the axial direction of the cylindrical surface.

  In addition, it is preferable to irradiate the X-ray 52 so as not to generate a plurality of tangents to the arc appearing in the cross section of the analysis target surface. For example, when the interface is a cylindrical surface, when X-rays with a size larger than the diameter of the cylinder are irradiated in the horizontal direction in which the optical axis of the X-ray is perpendicular to the axis of the cylinder, the cross section of the cylindrical surface is viewed , A tangent line is generated with respect to both the upper end and the lower end of the interface represented by a circle. In that case, since the diffraction line from the interface part which both tangents touch will be detected, it is difficult to specifically analyze the diffraction line only from the interface part which touches any one of the tangent lines. Therefore, as described above, the thickness of the X-ray is limited, or the optical axis of the X-ray and the position of the sample are relatively moved so that a single tangent is generated with respect to the arc of the analysis target surface. It is preferable to make it.

  When the sample S is irradiated with the X-ray 52, the optical axis of the sample S and the X-ray 52 is relatively moved to reach the other dissimilar material from one dissimilar material of the sample S through the interface. It is preferable to irradiate a plurality of regions with X-rays. For example, an elevating table (not shown) that raises and lowers the sample S is provided in the sample setting unit 20, and the sample S is moved up and down with respect to the optical axis of the fixed X-ray 52, thereby irradiating the sample S with the X-ray 52 irradiation position. Can be adjusted. Thereby, the change of the X-ray diffraction chart in the region before and after the interface Sb can be observed.

  Further, when analyzing the sample S by the method of the present invention, it is preferable to provide an X-ray detector 40 for confirming the position of the sample on the side opposite to the X-ray irradiation side of the sample S on the optical axis of the X-ray 52. . A part of the X-rays 52 irradiated to the sample S transmits the sample S as transmitted X-rays 56. By detecting the transmitted X-ray 56 with the X-ray detector 40 for confirming the position of the sample, it is possible to easily recognize which position the X-ray 52 is irradiated on the sample S. For example, as shown in the graph of FIG. 1, the cross-sectional position of the sample S, which is the average value of the average intensity of the transmitted X-rays 56 in the low-permeability material and the average intensity of the transmitted X-rays 56 in the high-permeability material, is expressed as the interface Sb. And so on. If the raising / lowering operation of the raising / lowering table is controlled on the basis of the interface position, it is possible to easily recognize how far the region away from the sample interface Sb is irradiated with the X-rays 52.

[Detection of diffraction lines]
When the sample is irradiated with X-rays 52, scattered X-rays are emitted from the constituent atoms at the irradiated location. The scattered X-rays interfere with each other and exhibit a diffraction phenomenon when the Bragg condition is satisfied, and are observed as a diffraction line 54 by the diffraction line detector 30. At that time, the X-ray 52 incident on the sample S, the sample S, and the diffraction detector 30 are interlocked by a goniometer so that the Bragg condition is always satisfied.

  The diffraction line detector 30 may be a zero-dimensional detector or a one-dimensional detector mounted on a so-called 2θ arm that rotates about the sample as a rotation center, but a two-dimensional detector is preferably used. If a two-dimensional detector is used, the X-ray diffraction pattern (Debye ring) becomes a circular arc with a complete concentric circle because the crystalline substance to be identified is highly oriented or the number of crystal grains is small. The diffraction line can be efficiently detected even for a sample that does not satisfy the above condition. The diffraction line detector 30 scans and measures the angle difference (2θ) between the X-ray diffraction direction and the incident direction and the diffraction line intensity. The relationship between the obtained angle difference (2θ) and diffraction line intensity is displayed as an X-ray diffraction chart. Since this angle difference (2θ) and diffraction line intensity are specific to the structure of the substance, the substance present near the interface can be identified from the obtained X-ray diffraction chart. The identification here includes obtaining information on the crystal such as the chemical composition, crystal state, crystal distortion, and crystal size of the crystalline substance.

[Other configurations]
In addition, the sample placement unit 20 may be provided with a heating means (not shown) for the sample S. Thereby, the sample S is heated to a predetermined temperature, and it can be observed whether or not the crystalline substance changes at the interface Sb of the sample as the heating temperature changes. When the X-ray diffraction is performed by destroying the bonding interface of different materials and exposing the peeled surface as in the prior art, the oxidation of the peeled surface further proceeds when the sample is heated. Therefore, it is predicted that the oxidizable element present at the interface before peeling becomes an oxide due to the exposure and heating of the peeling surface, and cannot be distinguished from the oxide existing at the interface before peeling. On the other hand, in the method of the present invention, since the analysis by the X-ray diffraction method is performed on the non-destructive interface, the crystalline substance such as oxide generated by heating is accurately analyzed instead of the exposure of the interface. be able to.

[Example 1]
Based on the method described above, a hermetic seal in which the lead of the semiconductor module is sealed to the eyelet with hard glass is used as a sample, and the oxide at the interface between the lead and the hard glass is identified. As shown in FIG. 1, the lead Si used was heated before being covered with the hard glass So, and an oxide film was formed on the interface Sb. As the sample S, a thin plate-shaped sample obtained by cutting out the lead Si covered with the hard glass So so as to include its axis is used (see the left diagram in FIG. 2). This sample S is placed on an elevating table (not shown) provided in the sample setting unit 20, and by operating this table, each part of the lead Si, the interface Sb, and the hard glass So is irradiated with X-rays 52. Is raised and lowered. In this embodiment, an X-ray detector 40 for confirming the sample position is disposed on the optical axis of the X-ray 52, and the intensity of the transmitted X-ray 56 is measured. As shown in the graph of FIG. 1, the cross-sectional position of the sample in which the intensity of the transmitted X-ray 56 is an average value of the average intensity of the transmitted X-ray 56 in the lead Si and the average intensity of the transmitted X-ray 56 in the hard glass So. Is the interface Sb. Then, the distance from the interface Sb to the center position (optical axis) of the X-ray is obtained from the lifting amount of the lifting table. In this example, the X-ray 52 is placed on the sample S so that the center of the X-ray is located at a total of three locations, a position of 25 μm from the interface Sb to the lead side and a position of 15 μm from the interface Sb and from the interface Sb to the hard glass side. Irradiation was performed, and the diffraction line 54 at each position was analyzed. The analysis conditions are as follows. The thickness of the oxide film (interface part) formed on the interface Sb was determined by microscopic observation of the cross section of the lead Si covered with the hard glass So. The transmittance was 95%, and the lead X-ray transmittance was 15% or less.

<Sample>
Lead (single wire)
Material: Kovar (Fe-29% Ni-17% Co-0.5% Mn-0.2% Si) All figures are mass%
Diameter: 0.5mm
Hard glass Material: Borosilicate glass (SiO ₂ -B ₂ O ₃ -K ₂ O)
Outer diameter: 3.0mm
Sample shape: Thin plate Sample size: Thickness 200μm
<X-ray>
Line type: Synchrotron radiation with an output of 25eV X-ray size (slit opening dimension)
Thickness: 0.03mm (30μm)
Width: 0.5mm
Irradiation direction: Direction tangential to the interface and perpendicular to the axial direction of the lead

  The analysis results are shown in the chart of FIG. The horizontal axis of the chart is a value (2θ) converted into a diffraction angle when CuKα1 is used as the X-ray. In this chart, (1) is the analysis result when X-rays are irradiated at a position of 15 μm from the interface to the hard glass side, (2) is the interface, and (3) is at a position of 25 μm from the interface to the lead side.

  First, as shown in the chart of FIG. 3A, in the chart of (1), there is a gentle undulation that seems to be due to scattering by hard glass around 25 °, and a Co peak is around 45 °. It's only a very small size. This shows that the chart of (1) analyzes a region consisting almost only of hard glass.

  Next, in the chart of (2), the point that there is a gentle undulation that seems to be due to scattering by hard glass around 25 ° is the same as the chart of (1), but the Co peak around 45 ° It is larger than the chart in (1), and a small Co peak is also observed near 52 °. This indicates that the chart in (2) almost analyzes the interface region.

  Next, in the chart of (3), the point where there is a gentle undulation that seems to be due to scattering by hard glass around 25 ° is the same as the chart of (1) and (2), but around 45 °. Both the Co peak and the Co peak near 52 ° are much larger than the chart in (2). This shows that the chart of (3) analyzes the region that consists almost of leads.

Further, the range of 30 ° to 40 ° in this chart is enlarged and shown in FIG. In the chart (1), no Fe ₂ O ₃ or FeO peak is observed, but in the charts (2) or (3), those oxide peaks are clearly recognized. Therefore, it can be seen that Fe ₂ O ₃ or FeO iron oxide is generated in the region of about 25 μm from the interface toward the lead side.

  In addition to the above evaluation, it is also possible to perform a quantitative analysis from an X-ray diffraction chart.

  In addition, this invention is not limited to said embodiment, A various change can be anticipated. For example, the sample is not limited to the hermetic seal of the semiconductor module, but the interface between the lead of various electronic parts including the terminal part of the cold cathode tube and its sealing material, and the joining of other dissimilar materials It can also be used to identify substances at the interface.

  The X-ray diffraction method of the present invention can be suitably used for identification of substances existing at the interface of different materials such as leads of various electronic components and sealing materials thereof.

10 X-ray irradiation source
15 slit
20 Sample placement section
30 Diffraction line detector
40 X-ray detector for sample position confirmation
52 X-ray 54 Diffraction line 56 Transmission X-ray S Sample
Si lead (low permeability material) Sb interface So hard glass (high permeability material)
100 Semiconductor module 110 Eyelet 110h Through hole 120 Semiconductor element
130 Lead 140 Cap 150 Lens 160 Hard glass

Claims (9)

An X-ray diffraction method for identifying a crystalline substance present at a bonding interface of different materials,
A process of arranging a sample whose analysis target surface is a region whose cross section is represented by a curve, of the bonding interface, between the X-ray irradiation source and the diffraction ray detector;
A process of irradiating the analysis target surface with X-rays in a tangential direction of the curve from the irradiation source;
And a step of detecting, with the diffraction line detector, a diffraction line generated along with the irradiation of the X-ray.   The X-ray diffraction method according to claim 1, wherein the sample has a thin plate shape in which the tangential direction is a thickness direction.   The X-ray diffraction method according to claim 1, wherein the diffraction line detector is a two-dimensional detector. The curve is an arc;
The X-ray diffraction method according to claim 1, wherein a thickness of the X-ray is less than a diameter of the arc.   5. One of the dissimilar materials is a low transmission material having a low X-ray transmittance, and the other is a high transmission material having a higher X-ray transmission than the low transmission material. The X-ray diffraction method according to any one of the above.   6. The X-ray diffraction method according to claim 5, wherein the low-permeability material is a lead of an electronic component, and the high-permeability material is glass that seals the lead in a lead penetration portion of the electronic component.   The X-ray diffraction method according to claim 6, wherein the X-ray is irradiated in a direction intersecting with an axial direction of the lead.   The X-ray diffraction method according to claim 1, wherein the X-ray is radiated light.   The X-ray diffraction method according to claim 1, wherein the crystalline substance is an oxide.

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