JP2014095640A - X-ray inspection heating device and planar heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a concrete configuration of an X-ray inspection heating device capable of uniform convective heating of a substrate without increasing the size of the device or complicating the device.SOLUTION: An X-ray inspection heating device for heating at least one surface of a sample 8 housed in a sample heating chamber 10 by convection and inspecting the sample with X-rays, includes: a planar heater 12 that has a number of ventilation holes 14A, 15A and 16A or slits (13C) formed therein and can transmit X-rays; gas supply means (air ducts 20 and blast pipes 22) that feeds gas into a space on a side of the planar heater 12 opposite to the side with the sample 8; and an X-ray transmission window 24 that blocks the sample heating chamber 10 from outside air.

Description

  TECHNICAL FIELD The present invention relates to a heating apparatus for X-ray inspection and a planar heater, and in particular, an object to be inspected such as a sample, which is useful for analyzing the cause of defects in solder joints during heating and behavior of various materials due to temperature changes. X-ray inspection heating apparatus capable of heating a target temperature to a target temperature or in accordance with a preset profile and observing a change in the state of the X-ray transmission image in real time, recording a temperature change, and a moving image, and The present invention relates to a planar heater suitable for use in the present invention.

  In recent years, the density of mounting substrates has increased, the number of layers has increased, and the materials used have been diversified. Therefore, in addition to the conventional optical inspection, the necessity of the X-ray inspection which can observe the behavior etc. at the time of the solder melting in the inside of a part or a joint part is increasing.

  In particular, the high-temperature X-ray inspection, which can heat a sample to a high temperature and observe changes in crystal structure and solder melting state, shows the melting state of solder in the joints of parts and the behavior during cooling in real time. This is useful for analyzing the cause of defects in solder joints.

  When a sample is subjected to X-ray inspection under heating conditions, conventionally, a gas heated outside the X-ray inspection visual field range is sprayed on the sample inside the inspection apparatus and observed. Although an X-ray inspection apparatus having a heating device has been proposed, a heating element required for the heating device includes a ceramic heater, a carbon fiber, and the like, and in some cases, it was easily broken. Therefore, there has been a demand for a robust, inexpensive, thin, and compact heater that can be heated within the X-ray visual field range and perform a clear X-ray inspection.

  Further, in order to perform an accurate inspection, it is necessary to heat the sample based on the set profile as quickly and uniformly as in the actual manufacturing. Therefore, a heating device capable of rapid and uniform heating has been demanded. Furthermore, with the miniaturization of parts, there is an increasing need to clearly observe extremely small parts at a high magnification, and in order to reduce the focal length, the heating device has been required to be thin.

  Therefore, Patent Document 1 proposes a heating device using a ceramic heater formed in a plate shape as a constituent material of the heating device.

  However, in the case of the method of observing the gas heated outside the conventional inspection apparatus by blowing it into the inspection apparatus, there is a problem that the temperature of the sample on the substrate is not uniform and sufficient temperature control cannot be performed. . In addition, there has been a problem that the state change of the sample accompanying the temperature change such as a void generation state or a wet state change at the time of melting the solder cannot be observed accurately and in real time along the required profile. Furthermore, when metal parts such as a motor, a shaft, and a fan are in the field of view, there is a problem that an inspection that penetrates vertically with X-rays is impossible.

  On the other hand, in the heating device known from Patent Document 1, a ceramic heater formed in a plate shape is used as a constituent material of the heating element, thereby preventing the constituent material of the heating device from blocking X-rays. However, the ceramic heater has a problem that its temperature rise is slow, temperature control is difficult, it is easy to crack, and durability is difficult. Further, since there is no mechanism for generating an air flow in the heating device, there is a problem that the temperature in the device is uneven.

  Currently, most reflow solder heating methods for printed circuit boards worldwide are mainly convection heating. This is because in many cases, components are mounted on the upper and lower sides of the glass epoxy substrate (the back surface is not flat), and heat conduction heating cannot be used.

  However, soldering behavior differs greatly between heat conduction heating and mainly convection heating that is actually performed in the market. This is because the temperature rise rate of each part such as the substrate, solder paste, and parts is different, and the amount of drying and oxidation of the solder paste is also different.

  For this reason, even if the mounting substrate is heated and inspected by heat conduction heating that may cause a phenomenon that does not actually occur, there is no point in inspecting the mechanism of various soldering defects caused by convection heating. These things are known as common sense by a soldering engineer.

  When inspecting a moving image of a substrate with X-rays, in order to inspect the actual soldering behavior, convection heating must be mainly performed. However, most of the conventionally proposed reflow heating furnaces for X-ray inspection are heat conduction heating.

  In order to solve such a problem, the inventor has proposed the techniques of Patent Documents 2 and 3, but it was not based on experience of manufacturing and assembling an actual machine.

JP-A-9-138073 JP 2011-2322029 A International Publication No. 2010/116809

  The present invention has been made on the basis of the above-mentioned problems of the prior art and the experience of manufacturing and assembling an actual machine. For X-ray inspection, the substrate can be uniformly convectively heated without increasing the size and complexity of the apparatus. It is a first object to provide a specific configuration of the heating device.

  It is a second object of the present invention to provide a planar heater suitable for use in the X-ray inspection heating apparatus as described above.

  In order to solve the first problem described above, the invention according to claim 1 is an X-ray for inspecting with X-rays by heating at least one surface of a sample accommodated in the sample heating chamber by convection. A heating apparatus for inspection, which has a large number of ventilation holes or slits and is capable of transmitting X-rays, and gas supply means for feeding gas into a space on the opposite side of the surface heater from the sample And an X-ray transmission window for shielding the sample heating chamber from outside air.

  In the invention according to claim 2, the planar heater is formed of a thin metal plate and an insulating plate formed of a material that transmits X-rays for reinforcing the metal plate from both sides, 2. The heating apparatus for X-ray inspection according to claim 1, wherein a large number of ventilation holes or slits are formed in at least one of the metal plate and the insulating plate.

  A third aspect of the present invention is the X-ray inspection heating apparatus according to the second aspect, wherein the metal plate is embedded in at least one of the insulating plates.

  According to a fourth aspect of the present invention, the vent hole or slit of the insulating plate on the sample side is formed obliquely or perpendicularly to the surface of the insulating plate, and the vent hole or slit of the insulating plate on the side opposite to the sample The heating apparatus for X-ray inspection according to claim 2 or 3, wherein the heating apparatus is formed perpendicularly or obliquely to the surface of the insulating plate.

  The invention according to claim 5 is the X-ray inspection heating apparatus according to claim 4, wherein the metal plate is embedded in an insulating plate opposite to the sample.

  According to a sixth aspect of the present invention, the planar heater includes an insulating plate formed of a material that transmits X-rays and a metal film formed in close contact with the insulating plate, and at least one of the insulating plate and the metal film. The X-ray inspection heating apparatus according to claim 1, wherein a large number of ventilation holes or slits are formed in the X-ray inspection heating apparatus.

  The invention according to claim 7 is configured such that the gas supply means includes a blower duct disposed around the sample heating chamber, and a blower pipe that feeds gas from the blower duct toward the center of the sample heating chamber. The X-ray inspection heating apparatus according to claim 1, wherein the X-ray inspection heating apparatus is provided.

  The invention according to claim 8 is the heating apparatus for X-ray inspection according to claim 1, wherein the planar heater is a metal plate in which a large number of ventilation holes or slits are formed.

  The invention according to claim 9 is characterized in that insulating plates are arranged above and below the metal plate via spacers, and a large number of ventilation holes or slits are formed at least on the insulating plate on the sample side. 8. The X-ray inspection heating apparatus according to 8.

  The X-ray inspection heating according to any one of claims 1 to 9, wherein the planar heater and the gas supply means are arranged on both sides of the sample. Device.

  The invention described in claim 11 is the X-ray inspection heating apparatus according to any one of claims 2 to 7, wherein the insulating plate is made of boron nitride.

  The X-ray inspection according to any one of claims 1 to 11, wherein the X-ray transmission window is made of mica and is reinforced by a reinforcing plate made of carbon fiber. Heating device.

  A thirteenth aspect of the present invention is the X-ray inspection heating apparatus according to any one of the first to eleventh aspects, wherein the X-ray transmission window is made of carbon fiber.

  In order to solve the second problem described above, the invention according to claim 14 is a thin metal plate capable of transmitting X-rays and transmits X-rays for reinforcing the metal plate sandwiched from both sides. A planar heater comprising: an insulating plate made of a material, and a plurality of ventilation holes or slits formed in at least one of the metal plate and the insulating plate.

  The invention according to claim 15 is the planar heater according to claim 14, wherein the metal plate is embedded in at least one of the insulating plates.

  According to a sixteenth aspect of the present invention, one ventilation hole or slit of the insulating plate is formed obliquely or perpendicularly to the surface of the insulating plate, and the other ventilation hole or slit of the insulating plate is the insulating plate. The planar heater according to claim 14 or 15, wherein the planar heater is formed perpendicularly or obliquely to the surface of the plate.

  The invention according to claim 17 is the planar heater according to claim 16, wherein the metal plate is embedded in an insulating plate on the side where the ventilation holes are formed perpendicular to the surface. is there.

  The invention according to claim 18 comprises an insulating plate formed of a material that transmits X-rays and a metal film formed in close contact with the insulating plate, and at least one of the insulating plate and the metal film has a vent hole or a slit. It is a planar heater characterized by being formed in large numbers.

  The invention according to claim 19 is characterized in that the metal film is formed in close contact and integral with the insulating plate by vapor deposition, plating or vapor deposition. It is a heater.

  The invention according to claim 20 is the planar heater according to claim 18 or 19, wherein the metal film is made of any one of FeCr, NiCr, NiCrFe, FeCrAl, CuMn, and CuNi-based alloy. .

  The invention according to claim 21 is the planar heater according to any one of claims 18 to 20, wherein the insulating plate is made of ceramics or glass.

The invention described in claim 22 is characterized in that the ceramic is any one of alumina ceramics Al ₂ O ₃ , silicon carbide SiC, aluminum nitride AlN, boron nitride BN, and zirconia oxide ZrO _2. Is a planar heater.

  According to the heating apparatus for X-ray inspection of the invention according to claim 1, fine temperature control can be performed while promoting convection by heating with a number of ventilation holes formed in the planar heater or gas passed through the slits. It becomes possible. In addition, the atmosphere in the sample heating chamber can be controlled, and combustion or oxidation can be prevented or controlled, and observation in a specific gas atmosphere can be performed. Furthermore, by making the shape of the planar heater a zigzag type, the current value and voltage flowing through the heating element can be controlled freely and easily. Thereby, the performance, specifications, standards, etc. of the heating device can be set freely and easily.

  According to the X-ray inspection heating apparatus of the invention according to claim 2, strength can be maintained by sandwiching a thin metal plate from both sides with an insulating plate.

  According to the heating apparatus for X-ray inspection of the invention according to claim 3 or 6, the planar heater can be composed of an extremely thin metal plate.

  According to the X-ray inspection heating apparatus of the fourth aspect of the invention, it is possible to achieve uniform heating by blowing a swirling flow on a sample and promoting convection without using a fan or the like.

  According to the heating apparatus for X-ray inspection of the invention according to claim 5, the processing of the insulating plate is easy.

  According to the X-ray inspection heating apparatus of the seventh aspect of the invention, the gas can be reliably fed into the sample heating chamber, and rapid uniform heating becomes possible.

  According to the X-ray inspection heating apparatus of the invention according to claim 8, the configuration of the planar heater is simple.

  According to the X-ray inspection heating apparatus of the invention according to claim 9, the sample can be uniformly heated by convection.

  According to the heating apparatus for X-ray inspection of the invention according to claim 10, convection heating from both sides of the sample becomes possible.

  According to the X-ray inspection heating apparatus of the invention according to claim 11 or 12, processing is easy without impairing X-ray transmission, and the strength of the insulating plate and the X-ray transmission window can be ensured.

  According to the X-ray inspection heating apparatus of the thirteenth aspect, the apparatus can be thinned by omitting the reinforcing plate.

  According to the planar heaters of the inventions according to claims 14 to 22, a planar heater suitable for use in the X-ray inspection heating apparatus as described above can be provided.

  Based on the above, the effects of the X-ray inspection heating apparatus according to the present invention will be listed below.

  The first effect is that the sample can be clearly observed by an X-ray inspection apparatus under heating conditions.

  The second effect is that the sample can be heated rapidly.

  The third effect is that the sample can be heated uniformly.

  The fourth effect is that the sample can be heated at a high temperature.

  The fifth effect is that a sample heating method can be selected.

  The sixth effect is that the cooling control of the sample is possible.

  The seventh effect is that the sample can be observed in real time.

  The eighth effect is that the present heating device can be freely tilted within the X-ray field of view, and the observation angle of the sample can be set freely.

  The ninth effect is that the device can be thinned.

  The tenth effect is that the device can be simplified.

  The eleventh effect is that the device is sturdy and highly durable.

  The twelfth effect is that the apparatus can be operated safely.

  The thirteenth effect is that the maintainability of the apparatus is high.

  The fourteenth effect is that the device is inexpensive and has good cost performance.

  Further, as a general common sense, it has been considered impossible to use a metal plate having a large atomic weight as a heater in terms of X-ray transmission. When the X-ray permeability of a metal is simply expressed, the greater the (atomic number) × (thickness), the lower the permeability. As a practical matter, when stainless steel SUS430 with a thickness of 30 μm was processed into a zigzag shape and experimented as a heater, there was no problem with X-ray transmission, and a sufficient calorific value was obtained, resulting in a long life. I understood. By reducing the thickness, the X-ray transmission can be increased, the resistance can be increased, and it can be used as a heater. In addition, this heater is extremely inexpensive, can be processed by etching, and has a high heat-resistant temperature and a long life.

Sectional drawing which shows the whole structure of embodiment of the heating apparatus for a X-ray inspection which concerns on this invention Part II enlarged view of FIG. Part III enlarged view of FIG. The top view which shows the shape of the planar heater used in the said embodiment Similarly, a plan view showing the shape of the insulating plate on the sample side Similarly enlarged sectional view (A) Plan view and (B) Cross section showing the shape of the insulating plate on the opposite side of the sample The top view which similarly shows the modification of the surface heater The top view which similarly shows the other modification of a planar heater Sectional drawing which shows the principal part structure of the modification of the heating apparatus for a X-ray inspection which employ | adopted the planar heater of FIG. The top view which shows the shape of the flame | frame used by the said embodiment The top view which similarly shows the shape of an air duct and an air duct

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view showing an overall configuration of an embodiment of a heating apparatus for X-ray inspection according to the present invention. In this figure, 8 is a sample which is a mounting substrate in which electronic components (chip components) 2 and 2 'are soldered to lands 4 and 4' with solder paste 6 and 6 ', and mounted on top and bottom, and 10 is a sample. The heating chamber 10A is an exhaust port to the outside of the X-ray apparatus, 12 is a planar heater, 14 and 16 are insulating plates having high heat resistance and heat conductivity, 17 is a coated conductor, 18 is a frame made of, for example, stainless steel, 19 is an energizing bolt, 20 is an air duct, 21 is a gas supply pipe, 22 is an air duct, 24 is an X-ray transmission window, 26 is a reinforcing plate that transmits X-rays, 28 is a support, and 40 is an X-ray. An X-ray generation unit 42 of the irradiation device is an X-ray light receiving device.

  In FIG. 1, the metal plate 13 and the insulating plates 14, 16 constituting the planar heater 12 are shown separated from each other, but the II and III parts of FIG. 1 are enlarged respectively in FIGS. 2 and 3. As shown, these may all be in close contact.

  The metal plate 13 is made of, for example, a thin stainless steel (eg, SUS430) plate having a thickness of 30 μm, and is formed into a zigzag shape as shown in FIG. 4 (A) by etching, for example, or as shown in FIG. 4 (B). A large number of ventilation holes 13B are provided. The ventilation hole 13B may be a slit. In FIG. 4, 13 </ b> A is a bolt hole through which the energizing bolt 19 is passed.

  Since the metal plate has an extremely low electric resistance, a large current may flow even at a low voltage. However, the electrical resistance and current value can be easily controlled by adopting a thin plate-like zigzag type or by forming a large number of ventilation holes 13B or slits. While using a general-purpose power supply or cable, a high calorific value can be shown.

  In addition, since the metal plate 13 is thin and cannot maintain a plate-like shape, as shown in FIGS. 2 and 3, for example, an insulating plate having a thickness of 1 mm (for example, boron nitride BN, ceramics, mica, etc.) from both sides. (Made) 14 and 16 can be used as a sandwich structure.

  Here, the position of the insulating plate 14 on the sample 8 side that does not overlap the metal plate 13 (in the case of FIG. 4A) or the position that overlaps the ventilation hole 13B of the metal plate 13 (in the case of FIG. 4B). As shown in FIG. 5, as shown in FIGS. 1 to 3, a large number of oblique ventilation holes 14A are formed with respect to the surface of the insulating plate 14 to generate a swirling flow to promote convection. Has been. Note that the direction of the oblique ventilation holes 14A is preferably the direction toward the center sample 8 as illustrated in FIG. 6A, but is not limited thereto, and as illustrated in FIG. It can be formed in various directions such as a direction toward the periphery or one direction as illustrated in FIG.

  On the other hand, the insulating plate 16 on the gas supply space side opposite to the sample 8 has ventilation holes 16A perpendicular to the surface thereof as shown in FIGS. 7A (plan view) and (B) (cross-sectional view). Many are formed. The insulating plate 16 is further formed with a recess 16B for embedding the metal plate 13. In the present embodiment, since the recess 16B is provided on the insulating plate 16 side where the vertical ventilation hole 16A is formed, processing is easy. The recess for embedding the metal plate 13 can be provided on the insulating plate 14 side, or can be provided on both the insulating plates 14 and 16.

  The configuration of the planar heater 12 is not limited to the sandwich structure as shown in FIGS. 2 and 3, but as shown in FIG. 8, for example, a vapor deposition method or a vapor deposition method is applied to the surface of a ceramic insulating plate 15. Alternatively, an integrated heater in which the metal film 15B is formed by a plating method or the like and the ventilation holes 15A are formed may be used. Furthermore, the ventilation hole may be a ventilation slit.

  Alternatively, for example, a single metal plate 13 having a ventilation slit 13C as shown in FIG. 9 is used, and the upper and lower insulating plates 14 are interposed via spacers 50 as shown in FIG. , 16 may be arranged apart from the above. In this case, convection can be promoted at intervals above and below the metal plate 13. Further, as shown by an arrow in FIG. 10, the apparatus can be thinned by supplying gas between the metal plate 13 and the insulating plate 16.

  The material of the metal plate is not limited to Fe-Cr alloy such as SUS430 or other stainless steel, and can be thinned, X-ray transmission is guaranteed by thinning, heat resistance, no oxidative deterioration, heater Ni-Cr alloy, Ni-Cr-Fe alloy, Fe-Cr-Al alloy, Cu-Mn alloy, Cu-Ni alloy, etc. It may be.

  The energization from the coated conductor 17 to the planar heater 12 is performed from a frame 18 as schematically shown in FIG. 11 via an energizing bolt 19 insulated using, for example, an insulating bush (not shown). In FIG. 11, 18 </ b> A is a bolt hole through which the energization bolt 19 is passed.

  12 (A) or 12 (B), the periphery of the frame 18 is a blower duct 20, and a blower pipe 22 made of glass, for example, is formed in an X shape from the blower duct 20 toward the center. (In the case of FIG. 12 (A)) or a rice field (in the case of FIG. 12 (B)). Here, the cross-sectional area of the air duct 20 is sufficiently larger than the cross-sectional area of the air duct 22, and even when, for example, gas is fed from one or two surroundings, uniform gas is at the center. To be supplied.

  In the embodiment of the present invention having the above-described configuration, in order to operate the heating device, first, a voltage is applied to the energizing bolt 19 via the coated conductor 17. The applied voltage may be a DC voltage or an AC voltage, but the current flows uniformly in the planar heater 12 via the energizing bolt 19. At this time, since the metal plate has a small resistance and is easily energized, a current flows easily, and a heat generation amount corresponding to the power is generated.

  Since the heat generation is uniform and the thermal conductivity of the metal plate itself is high, the temperature of the planar heater 12 rises rapidly and uniformly.

  For example, the sample 8 which is a printed wiring board is placed on the planar heater 12 via a support 28 having high heat resistance and high heat conductivity. The support 28 is preferably a plate or sheet of alumina ceramics, polyimide resin, silicone resin, fluororesin, mica, etc., but is not particularly limited, and the material can be freely selected according to the required temperature. Can do.

  The sample 8 can be directly placed on the planar heater 12 only through the insulating plate 14 having high heat resistance and heat conductivity. For this reason, with the rapid and uniform temperature rise of the planar heater 12, the sample 8 can also be rapidly and uniformly heated.

  Further, the amount of heat generation can be easily controlled by controlling the voltage while monitoring with a thermocouple (not shown) disposed near the sample 8, for example. Thereby, the temperature of the sample 8 can be controlled along the necessary profile.

  As the temperature of the planar heater 12 rises, the temperature of the sample 8 installed on the insulating plate 14 rises rapidly and uniformly in the plane. The heat-resistant temperature of the present embodiment is high, and the solder pastes 6 and 6 'can be sufficiently melted. As the temperature rises, the solder paste 6, 6 ′ is melted, and the electronic components 2, 2 ′ and the lands 4, 4 ′ are wetted and joined.

  In addition, real-time observation can be performed under a preset temperature profile, which can be used for elucidating the void generation mechanism.

  Further, since a heat transfer mechanism from outside the inspection visual field is not required, the angle of observation is not limited, the apparatus can be thinned and simplified, and manufacturing is easy. Further, since the metal plate itself has high strength, a highly durable heating device can be easily obtained.

  In the above embodiment, the planar heater 12 has a flat plate shape. By rounding or bending the plate, for example, a round tube type or a square tube type heating device as described in Patent Document 1 is used. It is also possible.

  In the present embodiment, heating by contact or radiation is performed by heating through the gas supplied from the gas supply pipe 21 via the blower duct 20 and the blower pipe 22 to the vent holes 14A and 16A provided in the planar heater 12. In addition, atmospheric heating by convection is added, and fine temperature control becomes possible. Not only can the temperature rise rate be controlled by the gas flow rate, but it is also possible to perform cycle operation of temperature rise and cooling. In addition, oxidation or combustion can be prevented or controlled by injecting an inert gas or the like, and observation under a specific gas atmosphere can be performed. Toxic gas generated from the sample 8 can be discharged from the exhaust port 10A to the outside. There is also an advantage that adverse effects on the sample 8 and the heating device can be prevented. Further, after the observation is completed, the sample 8 and the heating device can be rapidly cooled by blowing outside air or cold air.

  According to this embodiment, smooth heating by convection is possible from above and below. In addition, it is also possible to arrange | position a heating apparatus to one of upper or lower.

  The present embodiment is an X-ray inspection heating apparatus particularly useful for analyzing the cause of occurrence of defects at solder joints, and heats an inspection object such as a sample to a target temperature or according to a preset profile. It is possible to observe and record the state change in real time.

  Moreover, although the heating apparatus is installed horizontally in the figure, it can also be installed vertically or diagonally as required. It is possible to observe the sample from all angles by combining the installation method of the heating device and the sample setting method.

  In this embodiment, the X-ray transmission window 24, which is the range for observing the sample with X-rays, uses only a material having good X-ray transmission properties such as mica, so that wetting of the solder under various temperature conditions is performed. The behavior can be clearly observed. Furthermore, since the reinforcing plate 26 made of, for example, carbon fiber that can transmit X-rays is provided, sufficient strength can be secured.

  The number of the blow pipes 22 is not particularly limited, but by installing two or more, it is possible to eliminate unevenness in the flow of the gas, to make the temperature uniform, and to increase the heating rate depending on the gas flow rate. Can be controlled. Furthermore, by selecting the gas supplied from the blower tube 22, observation in a specific gas atmosphere can be performed, and oxidation or combustion can be prevented or controlled by injecting an inert gas or the like. Further, by configuring the blower tube 22 with a material having good X-ray permeability such as glass, it is possible to control the gas supply while maintaining the X-ray permeability.

  Further, in cooling, a cooling gas can be flowed from the blower pipe 22, and a rapid cooling control can be performed by providing a gas supply pipe dedicated to cooling. This enables quick cooling and control of the cooling state, enables observation of the effects of cooling on various phenomena such as the lift-off phenomenon, and also allows cycle operation of temperature rise and cooling. It becomes.

  In addition, by providing 10 A of exhaust ports on the sample heating chamber 10 of a heating apparatus, gas atmosphere and flow volume can be controlled and temperature control becomes easy. Moreover, the toxic gas etc. which generate | occur | produced from the sample 8 at the time of a heating can be discharged | emitted rapidly, and a highly safe heating apparatus can be provided.

  In this embodiment, the insulating plates 14 and 16, the X-ray transmission window 24, and the reinforcing plate 26 are made of ceramic, heat-resistant resin, heat-resistant rubber, glass, glass fiber, mica, carbon fiber subjected to insulation treatment, or It is characterized by being a combination of these. These materials are suitable because they have good X-ray permeability and are excellent in durability, heat resistance, and insulation. Specific examples include alumina ceramics, polyimide resins, silicone resins, fluororesins, glass, glass fibers, mica, insulating treated carbon plates and sheets, etc. It can be freely selected according to the required temperature and required strength. In particular, when the X-ray transmission window 24 is made of carbon fiber, the reinforcing plate 26 can be omitted to make the device thinner. In addition, as a method for insulating the carbon fiber, various means such as applying a coating film of an insulating material or doping an insulating agent can be considered, but this is not particularly limited.

  This embodiment is characterized in that planar heaters 12 are arranged on both sides of the sample 8. Thus, convection heating is performed from both sides of the sample 8, one side is convection heating, the remaining one side is heat conduction heating, one side is convection heating, the remaining side is not heated, etc. Thus, heating according to the state of the sample 8 becomes possible.

  In the heating device of the present invention, among the components, the planar heater 12 and the insulating plates 14 and 16 are repeatedly subjected to a heat cycle, so that it is expected to deteriorate faster than other components. Therefore, by modularizing the planar heater 12 and the insulating plates 14 and 16, it is possible to replace only the worn parts and improve the maintainability and cost performance.

  In this embodiment, since the X-ray transmission window 24 on the X-ray generation unit 40 side is small and the X-ray transmission window 24 on the X-ray light receiving device 42 side is large, it is possible to easily cope with a change in irradiation direction. It is also possible to have the same size. Further, the arrangement of the X-ray generator 40 and the X-ray light receiving device 42 is not limited to the example of FIG. 1 and may be upside down.

  The sample 8 is not limited to the double-sided mounting substrate, and may be a single-sided mounting substrate.

  Particularly, it is a heating device for X-ray inspection that is useful for analyzing the cause of defects in solder joints, and heats an object such as a sample to a target temperature or according to a preset profile, and changes its state Can be observed and recorded in real time.

2, 2 '... Electronic parts (chip parts)
8 ... Sample (mounting board)
DESCRIPTION OF SYMBOLS 10 ... Sample heating chamber 10A ... Exhaust port 12 ... Planar heater 13 ... Metal plate 13C ... Ventilation slit 14, 15, 16 ... Insulation plate 14A, 15A, 16A ... Ventilation hole 15B ... Metal film 16B ... Recess for metal plate embedding 17 DESCRIPTION OF SYMBOLS ... Coated conducting wire 18 ... Frame 19 ... Current supply bolt 20 ... Air duct 21 ... Gas supply pipe 22 ... Air supply pipe 24 ... X-ray transmission window 26 ... Reinforcement plate 40 ... X-ray generation part 42 ... X-ray light receiving device

Claims (22)

An X-ray inspection heating device for heating at least one surface of a sample accommodated in a sample heating chamber by convection and inspecting by X-ray,
A planar heater capable of transmitting X-rays with a large number of ventilation holes or slits;
Gas supply means for sending gas into the space opposite to the sample of the planar heater;
An X-ray transmission window that shuts off the sample heating chamber from outside air;
A heating apparatus for X-ray inspection, comprising:   The planar heater is formed of a thin metal plate and an insulating plate made of a material that transmits X-rays for reinforcing the metal plate from both sides, and at least one of the metal plate and the insulating plate The heating device for X-ray inspection according to claim 1, wherein a large number of ventilation holes or slits are formed in the heating device.   The heating apparatus for X-ray inspection according to claim 2, wherein the metal plate is embedded in at least one of the insulating plates. Ventilation holes or slits on the sample-side insulating plate are formed obliquely or perpendicular to the surface of the insulating plate
4. A heating apparatus for X-ray inspection according to claim 2, wherein the ventilation holes or slits of the insulating plate opposite to the sample are formed perpendicularly or obliquely to the surface of the insulating plate. .   The X-ray inspection heating apparatus according to claim 4, wherein the metal plate is embedded in an insulating plate opposite to the sample.   The planar heater is composed of an insulating plate made of a material that transmits X-rays and a metal film formed in close contact therewith, and a large number of ventilation holes or slits are formed in at least one of the insulating plate and the metal film. The heating apparatus for X-ray inspection according to claim 1.   The gas supply means includes an air duct arranged around the sample heating chamber and an air duct that sends gas from the air duct toward the center of the sample heating chamber. Item 7. A heating apparatus for X-ray inspection according to any one of Items 1 to 6.   The heating apparatus for X-ray inspection according to claim 1, wherein the planar heater is a metal plate in which a large number of ventilation holes or slits are formed.   The heating for X-ray inspection according to claim 8, wherein insulating plates are arranged above and below the metal plate via spacers, and at least a number of ventilation holes or slits are formed in the insulating plate on the sample side. apparatus.   The heating apparatus for X-ray inspection according to any one of claims 1 to 9, wherein the planar heater and gas supply means are disposed on both sides of the sample.   The heating apparatus for X-ray inspection according to claim 2, wherein the insulating plate is made of boron nitride.   The heating apparatus for X-ray inspection according to any one of claims 1 to 11, wherein the X-ray transmission window is made of mica and is reinforced by a reinforcing plate made of carbon fiber.   12. The X-ray inspection heating apparatus according to claim 1, wherein the X-ray transmission window is made of carbon fiber. A thin metal plate capable of transmitting X-rays;
An insulating plate made of a material that transmits X-rays for reinforcing the metal plate from both sides, and
A planar heater having a large number of ventilation holes or slits formed in at least one of the metal plate or the insulating plate.   The planar heater according to claim 14, wherein the metal plate is embedded in at least one of the insulating plates. One ventilation hole or slit of the insulating plate is formed obliquely or perpendicularly to the surface of the insulating plate,
The planar heater according to claim 14 or 15, wherein the other ventilation hole or slit of the insulating plate is formed perpendicularly or obliquely to the surface of the insulating plate.   The planar heater according to claim 16, wherein the metal plate is embedded in an insulating plate on a side where the ventilation holes are formed perpendicular to the surface.   An insulating plate made of a material that transmits X-rays, and a metal film formed in close contact with the insulating plate, and a large number of ventilation holes or slits are formed in at least one of the insulating plate and the metal film. Sheet heater.   19. The planar heater according to claim 18, wherein the metal film is formed in close contact with the insulating plate by vapor deposition, plating, or vapor deposition.   The planar heater according to claim 18 or 19, wherein the metal film is made of any one of FeCr, NiCr, NiCrFe, FeCrAl, CuMn, and a CuNi-based alloy.   The planar heater according to any one of claims 18 to 20, wherein the insulating plate is made of ceramics or glass. The planar heater according to claim 21, wherein the ceramic is any one of alumina ceramics Al ₂ O ₃ , silicon carbide SiC, aluminum nitride AlN, boron nitride BN, and zirconia oxide ZrO ₂ .

Images