JP2010261835A - X-ray inspection apparatus, and heating apparatus for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray inspection apparatus for seeing through a workpiece by X rays while the workpiece is uniformly heated when the workpiece is seen through in the thickness direction of a board while the workpiece such as the circuit board is heated. <P>SOLUTION: A heating unit 10 is provided so as to spray a hot blow to the workpiece W disposed on a sample stage (a table) 3. A hot blow spraying member 12 of the heating unit 10 is formed from a material with a high permeability rate of the X rays, and provided at a position at which it faces the workpiece W on the sample stage 3 in the direction of an optical axis of the X rays. While the hot blow is uniformly sprayed to the workpiece W and its temperature is uniformly maintained, the image quality is prevented from being degraded without an effect on an X-ray perspective image of the workpiece W due to the hot blow spraying member 12. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention irradiates an inspection object with X-rays, constructs an X-ray fluoroscopic image thereof, performs X-ray inspection of the article, and uses the X-ray inspection apparatus to heat the inspection object. The present invention relates to a heating device.

  An X-ray inspection apparatus is known as an apparatus for inspecting the presence or absence of internal defects and the internal structure of articles such as various industrial products. In this type of X-ray inspection apparatus, usually, a two-dimensional X-ray detector is arranged opposite to an X-ray generation apparatus that generates X-rays having a cone-shaped spread, and an object to be inspected is mounted between them. A structure provided with a sample stage such as a table is adopted.

  A technique for observing the behavior of the solder on the mounting board during the soldering process using such an X-ray inspection apparatus is often used. In other words, by preventing the occurrence of defective soldering in the solder reflow process and performing the X-ray fluoroscopy while heating the mounting board in order to set the optimal heating conditions when mounting various boards using a reflow furnace. Many methods for observing the thermal behavior of solder have been adopted.

  An X-ray inspection apparatus to which a function for heating the inspection object is added is used for observing the thermal behavior of the inspection object. A typical heating method in this type of apparatus is a method using hot air (see, for example, Patent Documents 1 and 2), and injecting hot air toward an object to be inspected placed on a sample stage and heating X The X-ray fluoroscopic image of the inspection object is observed by irradiating the line. A hot-air injection member such as a nozzle that injects hot air toward the object to be inspected must be provided close to the object to be inspected, but in order not to obstruct the perspective of the object to be inspected by X-rays, Arranged outside the range. FIG. 3 conceptually shows an example thereof. In FIG. 3, 31 is an X-ray generator and 32 is an X-ray detector. A hot air jet member 34 is placed in the vicinity of an inspection object W such as a substrate placed on the sample stage 33, and the hot air jet member 34 is the focal point 31 a of the X-ray generator 31 and the center of the X-ray detector 2. Is a position deviated from the X-ray optical axis connecting the X-rays, more specifically, a position away from the path of the X-ray transmitted through the inspection object W, whereby a hot-air injection member is added to the X-ray fluoroscopic image of the inspection object W 34 images are prevented from being affected.

JP 2005-353712 A JP 2005-274194 A

  By the way, in the conventional X-ray inspection apparatus with a heating function as described above, especially when a flat inspection object such as a circuit board is seen through in the thickness direction, the hot air jet member is located on the side of the inspection object. Since the hot air is jetted from the surface toward the surface, the uniformity of temperature in the object to be inspected is likely to be impaired, and the purpose of the inspection may not be achieved.

  The present invention has been made in view of such circumstances, and even when a flat inspection object such as a circuit board is seen through in the thickness direction, X-ray fluoroscopy is performed while heating the inspection object uniformly. An object of the present invention is to provide an X-ray inspection apparatus that can be used and a heating device used in the X-ray inspection apparatus.

  In order to solve the above-described problems, an X-ray inspection apparatus according to the present invention is provided with a sample stage between an X-ray generator and an X-ray detector arranged opposite to each other, and an object to be inspected disposed on the sample stage. In the X-ray inspection apparatus for constructing an X-ray transmission image, a heating unit for injecting hot air onto the inspection object placed on the sample stage is provided, and the hot air injection member of the heating unit has an X-ray transmittance. And is characterized by being provided at a position facing the inspection object of the sample stage in the X-ray optical axis direction connecting the X-ray generator and the X-ray detector ( Claim 1).

  Here, in the present invention, the material having a high X-ray transmittance forming the hot-air jet member can be Be, B, C or an inorganic material containing them (Claim 2), or The material having a high X-ray transmittance that forms the hot air jet member can be polyimide, polyetheretherketone, or polyphenylene sulfide.

  In addition, the structure of the hot air injection member in the present invention includes a hot air passage including two flat plates provided at a predetermined distance from each other, and at least one of the flat plates is provided on the sample stage. A structure in which a plurality of hot air jets directed to the object to be inspected are formed (Claim 4), or a hot air passage composed of a plurality of pipes, and a plurality of pipes facing the object to be inspected on the sample stage. The structure (Claim 5) in which the hot air injection port is formed can be suitably employed.

  And in this invention, the said hot air injection member is arrange | positioned in a housing | casing, a hot air is injected only in the housing | casing, and this housing | casing discharge port for discharging the hot air ejected in the said housing | casing outside And at least the wall that transmits X-rays from the X-ray generator is formed of a material having a high X-ray transmittance, and the object to be inspected is It is desirable to adopt a configuration (Claim 6) arranged inside the housing.

  On the other hand, the heating apparatus for an X-ray inspection apparatus according to the present invention is provided with a sample stage for placing an object to be inspected between an X-ray generator and an X-ray detector arranged opposite to each other. A heating apparatus for an X-ray inspection apparatus for heating an inspection object, which is used in an X-ray inspection apparatus for constructing an X-ray transmission image of the inspection object, comprising: a hot air supply apparatus; A hot air injection member for injecting hot air onto the inspection object on the sample stage is provided, and the hot air injection member is formed of a material having a high X-ray transmittance. It is characterized by being attached in a state facing the X-ray optical axis direction connecting the X-ray detector and the X-ray detector (Claim 7).

  Here, in the heating apparatus for an X-ray inspection apparatus according to the present invention, the hot air supply member is disposed in a housing, hot air is jetted only by the housing, and hot air blown into the housing is blown into the housing. Of the walls constituting the housing, at least the wall through which the X-ray from the X-ray generator transmits is formed of a material having a high X-ray transmittance. In addition, a configuration in which the casing is used while being arranged on the sample stage and the object to be inspected is arranged in the casing (Claim 8) can be suitably employed.

  In the present invention, a hot air jet member that jets hot air to an object to be inspected is formed of a material having a high X-ray transmittance, and is formed in the X-ray optical axis direction with respect to the object to be inspected placed on a sample stage. Arrange at the opposite position. That is, the hot air jet member is disposed in the X-ray fluoroscopic field. As a result, the image of the hot air jet member overlaps the image of the object to be inspected. However, the material of the hot air jet member is made of a material having a high X-ray transmittance such as carbon, so Does not affect observation.

  The material having a high X-ray transmittance used for the hot-air jet member has a high X-ray transmittance and can withstand the heating temperature, for example, a material that can withstand 250 ° C. when observing the solder reflow process. Engineering such as Be, B, C or inorganic materials containing them as in the invention according to 2, or polyimide, polyetheretherketone, polyphenylene sulfide, etc., which are resins having excellent heat resistance as in the invention according to claim 3 Plastic can be used.

  The structure of the hot air injection member is not particularly limited, but two flat plates with a gap are used as in the invention according to claim 4 and a plurality of hot air jet members are provided on one flat plate due to the balance between the material used and its workability. Or a structure in which a plurality of holes are formed in each of a plurality of round pipes or square pipes as in the invention according to claim 5 can be used.

  In addition, the hot air injection member is arranged in the housing, the inspection object is also arranged in the housing, hot air is injected from the hot air injection member only into the housing, and the hot air blown into the housing is blown in the housing. The structure of the invention according to claim 6 is an X-ray generator using hot air and an X-ray detector. As well as alleviating the effects of heat, it is possible to confine a certain amount of heat inside the housing, which is excellent in terms of thermal efficiency.

  Here, examples of the material having a high X-ray transmittance used for the wall of the housing include materials equivalent to those used for the hot air jet member.

  According to the present invention, hot air is sprayed from an ideal direction and position on an inspection object, for example, by heating a circuit board, without substantially reducing the image quality of the X-ray fluoroscopic image of the inspection object. On the other hand, when seeing through in the thickness direction, hot air can be jetted through a plurality of holes from a position close to the surface of the circuit board and facing the surface of the circuit board. The uniformity of the heating temperature can be greatly improved.

  In addition, according to the heating apparatus for an X-ray fluoroscopic apparatus of the present invention, the above-described effects can be achieved only by mounting the X-ray fluoroscopic apparatus on an existing X-ray inspection apparatus. According to the configuration in which the hot-air jet member is accommodated, it is only necessary to arrange the casing on the sample stage of the existing X-ray inspection apparatus, and a heating function can be easily added.

It is principal part sectional drawing of embodiment of this invention. It is AA sectional drawing of FIG. It is explanatory drawing of the principal part structure of the conventional X-ray inspection apparatus with a heating function.

DESCRIPTION OF SYMBOLS 1 X-ray generator 2 X-ray detector 3 Table 10 Heating unit 11 Case 11a Ceiling plate 11b Bottom plate 11c Hot-air supply port 11d Exhaust port 12 Hot-air injection member 12a, 12b Carbon plate 12c Hole 12d Side wall 13 Air supply pipe 14 Sample stand 14a Carbon plate 14b Support member W Inspected object

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a cross-sectional view of the main part of an embodiment of the present invention, and FIG.

  The X-ray generator 1 generates cone-beam X-rays vertically upward, and a two-dimensional X-ray detector 2 is disposed vertically above the X-ray generator 1. A table 3 as a sample stage is arranged between the X-ray generator 1 and the X-ray detector 2, and the table 3 is moved in the vertical direction and the horizontal direction by a drive mechanism (not shown). Can do.

  A heating unit 10 is placed on the table 3. The heating unit 10 includes a housing 11 and a hot air jet member 12 disposed inside the housing 11. The casing 11 has a ceiling plate 11a and a bottom plate 11b made of a material having a high X-ray transmittance, such as a carbon plate, and a door (not shown) for taking the inspection object W into and out of an appropriate portion of the side wall portion. An air supply port 11c for introducing an air supply pipe 13 to be described later, a heat converter 15 for converting the introduced air into hot air having a predetermined temperature, and air inside the housing 11 are externally provided. A discharge port 11d for discharging is provided.

  The hot air injection member 12 has a structure in which the periphery of two carbon plates 12a and 12b parallel to each other with a predetermined interval is sealed with a side wall 12d, and in the space between these carbon plates 12a and 12b The hot air generated by heating the air supplied from the external supply device (not shown) through the air supply pipe 13 by the hot air converter 15 is supplied. A plurality of holes 12c are formed in the lower carbon plate 12b of the carbon plates 12a and 12b, and the hot air supplied between the carbon plates 12a and 12b is directed downward through the holes 12c. Is injected into.

  A sample stage 14 for placing an object W to be inspected is disposed inside the housing 11. The sample stage 14 has a structure in which a support member 14b for an object W to be protruded is provided on a carbon plate 14a. In this example, the object W is a plate-shaped article such as a circuit board. An example is shown in which the plate thickness direction is arranged along the vertical X-ray optical axis direction, and this direction is seen through. The hot-air jet member 12 faces the object W placed on the sample table 14 in the X-ray optical axis direction connecting the focal point 1a of the X-ray generator 1 and the center of the X-ray detector 2. ing. That is, as shown in FIG. 2, the hot air jet member 12 covers the upper side of the inspection object W on the sample stage 14, and the X-rays from the X-ray generator 1 pass through the inspection object W and the X-ray detector. 2 is in a state of being located on a path incident on the beam 2. With this arrangement, the hot air sprayed from the holes 12c formed in the carbon plate 12b on the lower side of the hot air spray member 12 is sprayed uniformly onto the upper surface of the inspection object W placed on the sample table 14. Will be.

  The heating temperature can be controlled, for example, by providing a temperature sensor in the vicinity of the inspection object W and drivingly controlling the hot air supply device so that the temperature detection result by the temperature sensor becomes the set temperature.

  According to the above embodiment, as a result of the hot air being uniformly injected onto the surface of the inspection object W through the plurality of holes 12c formed in the hot air ejection member 12, the entire temperature of the inspection object W is uniform. It will be a thing. Here, the X-rays that pass through the inspection object W also pass through the ceiling plate 11 a and the bottom plate 11 b of the housing 11, the carbon plate 14 a of the sample stage 14, and the carbon plates 12 a and 12 b of the hot air ejection member 12. However, since these are all made of a material having a high X-ray transmittance, they hardly affect the X-ray fluoroscopic image of the inspection object W to be obtained.

  Here, in the above embodiment, the example in which the hot-air ejection member 12 and the inspection object W are accommodated in the casing 11 and placed on the table 3 is shown, but the casing 11 is not necessarily required. When the required heating temperature is relatively low and it is not necessary to consider the thermal influence on the surrounding members, the housing 11 is unnecessary.

  Moreover, the structure of the hot air supply member 12 is a structure in which a plurality of holes 12c are formed in the carbon plate 12b on the side facing the inspection object W using the two carbon plates 12a and 12b spaced apart as described above. In addition to this, a plurality of round pipes and square pipes made of a material having a high X-ray transmittance are used, and these are arranged opposite to the inspection object W in the X-ray optical axis direction. A structure in which a plurality of holes are formed in a portion facing W and the hot air is jetted may be used.

  Here, as a hot air generating mechanism, in addition to the method of hot air from the outside by the hot air converter in the housing as described above, a method of generating hot air with an external supply device and transporting it into the housing, Alternatively, it is possible to adopt a method in which an electric current is passed through the ejection member and the temperature of the air is raised by the Joule heat.

  Furthermore, in the above embodiment, the example in which the present invention is applied to the X-ray inspection apparatus having the X-ray optical axis in the vertical direction has been shown. Of course, the present invention can be equally applied. In this case, the sample stage may be provided with a mechanism for holding the object to be inspected instead of the table, and the hot air jet member is inspected by being held by the sample stage. What is necessary is just to arrange | position so that it may oppose an X-ray optical axis direction with respect to a thing.

  Further, the material of the portion of the hot air injection member 12 through which X-rays pass is also a carbon plate, B (boron), Be (beryllium) or an inorganic material containing them, a resin that can withstand relatively high temperatures, such as polyimide. , Polyether ether ketone, polyphenylene sulfide and the like can also be used.

Claims (8)

In an X-ray inspection apparatus in which a sample stage is provided between an X-ray generator and an X-ray detector arranged to face each other, and an X-ray transmission image of an inspection object arranged on the sample stage is constructed.
A heating unit for injecting hot air onto the inspection object arranged on the sample stage is provided, and a hot air injection member of the heating unit is formed of a material having a high X-ray transmittance, and the inspection object of the sample stage The X-ray inspection apparatus is provided at a position facing the X-ray optical axis direction connecting the X-ray generator and the X-ray detector.   2. The X-ray inspection apparatus according to claim 1, wherein the material having a high X-ray transmittance forming the hot-air jet member is Be, B, C, or an inorganic material containing them.   2. The X-ray inspection apparatus according to claim 1, wherein the material having a high X-ray transmittance that forms the hot air injection member is polyimide, polyetheretherketone, or polyphenylene sulfide.   The hot air injection member includes a hot air passage including two flat plates provided at a predetermined distance from each other, and at least one of the flat plates faces the inspection object on the sample stage. The X-ray inspection apparatus according to claim 1, wherein a plurality of hot air injection ports are formed.   The hot air injection member includes a hot air passage composed of a plurality of pipes, and each of the pipes is formed with a plurality of hot air injection ports facing an object to be inspected on the sample stage. The X-ray inspection apparatus according to any one of 2 and 3.   The hot air injection member is disposed in the housing, and hot air is ejected only into the housing, and the housing is provided with a discharge port for discharging the hot air ejected into the housing to the outside. Of the wall bodies constituting the housing, at least the wall body through which the X-rays from the X-ray generator are transmitted is formed of a material having a high X-ray transmittance, and the object to be inspected is disposed inside the housing. The X-ray inspection apparatus according to any one of claims 1, 2, 3, 4, and 5. A sample stage for placing an inspection object is provided between an X-ray generator and an X-ray detector arranged opposite to each other, and an X-ray for constructing an X-ray transmission image of the inspection object on the sample stage A heating apparatus for an X-ray inspection apparatus used for an inspection apparatus for heating an object to be inspected,
A hot air injection member for injecting hot air onto the inspection object on the sample stage is provided, and the hot air injection member is formed of a material having a high X-ray transmittance. A heating apparatus for an X-ray inspection apparatus, wherein the heating apparatus is attached in a state of being opposed to each other in the X-ray optical axis direction connecting the X-ray detector and the X-ray detector.   8. The heating apparatus for an X-ray inspection apparatus according to claim 7, wherein the hot air supply member is disposed in a casing, hot air is jetted only into the casing, and hot air blown into the casing is blown into the casing. A discharge port for discharging to the outside is provided, and at least the wall body through which the X-ray from the X-ray generator transmits is formed of a material having a high X-ray transmittance, among the wall bodies constituting the housing, The heating apparatus for an X-ray inspection apparatus, wherein the casing is used while being disposed on the sample stage, and the inspection object is disposed within the casing.

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