The present invention relates to an ultrasonic inspection method which inspects an inspection object such as an electronic component in a dry state.
As means to realize a small-sized and thin product, that has been a trend in these days, a mounting area is required to be reduced, thus the number of electronic components having a rear surface electrode such as BGA and CSP has been increased. When the electronic component having a rear surface electrode is used, the joined portion thereof can not be inspected by means of optical means. Accordingly, another means is required to assure the quality.
Conventionally, there are a known method of using X-rays and ultrasonic inspection method as a method of observing the inside of the electronic component. The method of using X-rays has a great effect on inspections for disconnection, short and abnormal volume. However, the method is not suitable for an inspection for the joined portion such as separation. Since an ultrasonic wave is reflected by a portion having a different acoustical property, the ultrasonic inspection method is suitable for the inspection for the joined portion such as separation. In the ultrasonic inspection method, an inspection object is immersed in a solution as an ultrasonic wave transmission medium, and inspected by transmitting/receiving the ultrasonic wave to/from the inspection object via the solution. However, since the inspection object is immersed in the solution, the electrode materials of the inspection object are eluted as ions in the solution, and thus the reliability is lowered. In addition, since the inspection object is immersed in the solution, the ultrasonic inspection method can not be performed at a production site.
In (Patent Document 1) and (Patent Document 2), there are disclosed dry-type ultrasonic inspection methods which inspect the inspection objects without immersing the inspection objects in the solution.
Patent Document 1: JP-A-2003-177117
Patent Document 2: JP-A-11-304771
In a dry-type ultrasonic inspection method described in (Patent Document 1), a container of which the bottom surface is closed with a polymer film and which stores an ultrasonic wave transmission medium therein is used, the polymer film is pressed against an inspection object, and an ultrasonic wave transmitted to the inspection object via the ultrasonic wave transmission medium and the polymer sheet is received for the inspection. Accordingly, the method is suitable for inspections for all parts in a production process as compared with that of (Patent Document 1). However, in order to repeat the inspection in the production process, the polymer film is required to be exchanged, and it is difficult to automatically attach/remove the polymer film to/from the container.
In (Patent Document 1), in order to improve the adhesion between the polymer sheet and the inspection object, a process of discharging air between the polymer sheet and the inspection object is required, and the inspection object requires a space for pressing an air-tight sealing member between the inspection object and the surroundings thereof. Accordingly, the process can not be performed on a substrate having a high mounting density under the present circumstances.
In (Patent Document 2), there is disclosed an inspection method for a tube. However, the method can not be applied to an inspection object such as an electronic component of a mounting substrate, which requires a detailed inspection.
An object of the invention is to provide an ultrasonic inspection device suitable for the inspection object such as an electronic component of a mounting substrate, which requires the detailed inspection.
According to a first aspect of the invention, there is provided an ultrasonic inspection device comprising: a medium tank of which the bottom surface is closed with a polymer film and which is hermetically sealed with an ultrasonic wave transmission medium stored therein; and an ultrasonic probe of which at least the distal end is immersed in the ultrasonic wave transmission medium stored in the medium tank, wherein the polymer film is stuck to the bottom of the medium tank, an inspection object and the medium tank are relatively moved to bring the inspection object into contact with the polymer film, and a distance between the ultrasonic probe and the inspection object is set for inspections so that an ultrasonic wave transmitted from the ultrasonic probe and reflected by the inspection object is received by the ultrasonic probe.
According to a second aspect of the invention, there is provided the ultrasonic inspection device according to the first aspect, wherein a plurality of the ultrasonic probes are provided, and the plurality of ultrasonic probes are exchangeable.
According to a third aspect of the invention, there is provided an ultrasonic inspection device comprising: a medium tank of which the bottom surface is closed with a polymer film and which is hermetically sealed with an ultrasonic wave transmission medium stored therein; and an ultrasonic probe of which at least the distal end is immersed in the ultrasonic wave transmission medium stored in the medium tank, wherein an opening formed an end face on in the bottom surface side is provided in the medium tank, the polymer film is stuck and held by reducing the pressure in the opening, an inspection object and the medium tank are relatively moved to bring the inspection object into contact with the polymer film, and an ultrasonic wave transmitted from the ultrasonic probe and reflected by the inspection object is received by the ultrasonic probe for inspections.
According to a fourth aspect of the invention, there is provided an ultrasonic inspection device comprising: a medium tank of which the bottom surface is closed with a polymer film and which is hermetically sealed with an ultrasonic wave transmission medium stored therein; and an ultrasonic probe of which at least the distal end is immersed in the ultrasonic wave transmission medium stored in the medium tank, wherein the distal end of the medium tank is narrower than the base end of the medium tank, the distal end is covered by the polymer film to close the distal end opening of the medium tank, an inspection object and the medium tank are relatively moved to bring the inspection object into contact with the polymer film, and an ultrasonic wave transmitted from the ultrasonic probe and reflected by the inspection object is received by the ultrasonic probe for inspections.
According to a fifth aspect of the invention, there is provided an ultrasonic inspection method comprising: sealing a medium tank by closing the bottom surface opening thereof with a polymer film; sticking the polymer film to the bottom of the medium tank; injecting an ultrasonic wave transmission medium so as to immerse at least the distal end of an ultrasonic probe while reducing the pressure of the inside of the medium tank; bringing an inspection object into contact with the polymer film by relatively moving the inspection object and the medium tank; and setting a distance between the ultrasonic probe and the inspection object for inspections so as to allow the ultrasonic probe to receive an ultrasonic wave transmitted from the ultrasonic probe and reflected by the inspection object.
According to a sixth aspect of the invention, there is provided an ultrasonic inspection method comprising: sealing a medium tank by closing the bottom surface opening thereof with a polymer film; sticking the polymer film to the medium tank by reducing the pressure in the opening formed in an end face on the bottom surface side; injecting an ultrasonic wave transmission medium so as to immerse at least the distal end of an ultrasonic probe; bringing an inspection object into contact with the polymer film by relatively moving the inspection object and the medium tank; and allowing the ultrasonic probe to receive an ultrasonic wave transmitted from the ultrasonic probe and reflected by the inspection object for inspections.
According to a seventh aspect of the invention, there is provided an ultrasonic inspection method comprising: sealing a medium tank by closing the bottom surface opening thereof with a polymer film; sticking the polymer film to the bottom of the medium tank by reducing the pressure of the inside of the medium tank; injecting an ultrasonic wave transmission medium so as to immerse at least the distal end of an ultrasonic probe while reducing the pressure of the inside of the medium tank; pressurizing the inside of the medium tank further in a state where an inspection object comes into contact with the polymer film by relatively moving the inspection object and the medium tank; and allowing the ultrasonic probe to receive an ultrasonic wave transmitted from the ultrasonic probe and reflected by the inspection object for inspections.
According to an eighth aspect of the invention, there is provided an ultrasonic inspection method comprising: sealing a medium tank by closing the bottom surface opening thereof with a polymer film; sticking the polymer film to the medium tank by reducing the pressure in the opening formed in an end face on the bottom surface side; injecting an ultrasonic wave transmission medium so as to immerse at least the distal end of an ultrasonic probe; pressurizing the inside of the medium tank further in a state where an inspection object comes into contact with the polymer film by relatively moving the inspection object and the medium tank; and allowing the ultrasonic probe to receive an ultrasonic wave transmitted from the ultrasonic probe and reflected by the inspection object for inspections.
According to a ninth aspect of the invention, there is provided an ultrasonic inspection method comprising: sealing a medium tank by closing the bottom surface opening thereof with a polymer film; sticking the polymer film to the bottom of the medium tank by reducing the pressure of the inside of the medium tank; injecting an ultrasonic wave transmission medium so as to immerse at least the distal end of an ultrasonic probe while reducing the pressure of the inside of the medium tank; wetting the polymer film with alcohol before or after the injection of the ultrasonic wave transmission medium into the medium tank; pressurizing the inside of the medium tank further in a state where an inspection object comes into contact with the polymer film by relatively moving the inspection object and the medium tank; and allowing the ultrasonic probe to receive an ultrasonic wave transmitted from the ultrasonic probe and reflected by the inspection object for inspections.
According to a tenth aspect of the invention, there is provided an ultrasonic inspection method comprising: sealing a medium tank by closing the bottom surface opening thereof with a polymer film; sticking the polymer film to the medium tank by reducing the pressure in an opening formed in an end face on the bottom surface side; injecting an ultrasonic wave transmission medium so as to immerse at least the distal end of an ultrasonic probe; wetting the polymer film with alcohol before or after the injection of the ultrasonic wave transmission medium into the medium tank; pressurizing the inside of the medium tank further in a state where an inspection object comes into contact with the polymer film by relatively moving the inspection object and the medium tank; and allowing the ultrasonic probe to receive an ultrasonic wave transmitted from the ultrasonic probe and reflected by the inspection object for inspections.
According to an eleventh aspect of the invention, there is provided an ultrasonic inspection method comprising: sealing a medium tank by closing the bottom surface opening thereof with a polymer film; sticking the polymer film to the bottom of the medium tank by reducing the pressure of the inside of the medium tank; injecting an ultrasonic wave transmission medium so as to immerse at least the distal end of an ultrasonic probe while reducing the pressure of the inside of the medium tank; pressurizing the inside of the medium tank further in a state where an inspection object of which the surface is wet with alcohol comes into contact with the polymer film by relatively moving the inspection object and the medium tank; and allowing the ultrasonic probe to receive an ultrasonic wave transmitted from the ultrasonic probe and reflected by the inspection object for inspections.
According to a twelfth aspect of the invention, there is provided an ultrasonic inspection method comprising: sealing a medium tank by closing the bottom surface opening thereof with a polymer film; sticking the polymer film to the medium tank by reducing the pressure in the opening formed in an end face on the bottom surface side; injecting an ultrasonic wave transmission medium so as to immerse at least the distal end of an ultrasonic probe; pressurizing the inside of the medium tank further in a state where an inspection object of which the surface is wet with alcohol comes into contact with the polymer film by relatively moving the inspection object and the medium tank; and allowing the ultrasonic probe to receive an ultrasonic wave transmitted from the ultrasonic probe and reflected by the inspection object for inspections.
In an ultrasonic inspection device and an ultrasonic inspection method according to the invention, an inspect object such as an electronic component of a mounting substrate, which requires a detailed inspection, can be inspected in a dry state, and it is possible to realize an ultrasonic inspection suitable to be performed in production sites.
Hereinbelow, an ultrasonic inspection method according to the invention will be described on the basis of embodiments shown in FIGS. 1 to 11.
FIGS. 1 to 4 illustrate (a first embodiment) of the invention.
FIGS. 1(a) to 1(d) illustrate an ultrasonic inspection process.
As shown in
When the polymer film 2 is attached to the medium tank 1, the polymer film 2 is pressed against the bottom surface of the medium tank 1 as shown in
Subsequently, while continuously depressurizing (A) the inside 4 of the medium tank 1, water 5 as an ultrasonic wave transmission medium is injected into the inside 4 of the medium tank 1 as shown in
When the water 5 is injected in this manner, the center of the polymer film 2 is swollen downward because of the weight of the water 5. In this state, a stage 7 on which an inspection target substrate 6 is placed is lifted in a direction indicated by the arrow B as shown in FIGS. 1(c) and 1(d) to cover around the inspection portion 8 of the substrate 6 by the bottom of the medium tank 1. In the medium tank 1 pressed against the substrate 6 with the polymer film 2 interposed therebetween, the polymer film 2 is elastically deformed along the inspection portion 8 of the substrate 6.
In this state, a distance between the ultrasonic probe and the inspection object is adjusted and set so as to allow the ultrasonic probe to receive the ultrasonic wave transmitted from the ultrasonic probe 3 and reflected by the target-depth portion of the inspection portion 8 of the substrate 6, the ultrasonic wave is emitted, the ultrasonic wave reflected by the inspection portion 8 of the substrate 6 is received by the ultrasonic probe 3, and then a consistency in the target portion of the inspection portion 8 is inspected on the basis of a time interval between the transmission and the reception.
As described above, since the polymer film 2 is stuck and held to the medium tank 1 by the depressurization (A), the polymer film 2 is elastically deformed along the inspection portion 8 of the substrate 1 by pressing the substrate 6 against the bottom of the medium tank 1 with the polymer film 2 interposed therebetween as shown in
Accordingly, a process of discharging air between the polymer sheet and the inspection object is not required and the inspection object is also not required to have a space for pressing an air-tight sealing member between the inspection object and the surroundings thereof in order to improve the adhesion between the polymer sheet and the inspection object as shown in (Patent Document 1), thus the above-described process is suitable for the inspection for an in-line substrate having a high mounting density.
The polymer film 2 is damaged by repetitions of the inspection, and thus the accuracy of the inspection result is considered to be lowered. In this case, when the depressurization (A) is removed in a state where the polymer film 2 is moved over a waste container 9 as shown in
Since the used polymer film 2 is not incorporated in the water 5 collected in the waste container 9, it is possible to draw and use the water 5 to be re-injected into the medium tank 1 in the process of
A winding body 12 shown in
The stopped belt-shaped film with the tension applied thereto is pressed against the bottom of the medium tank 1, the medium tank 1 is depressurized (A) to stick and hold the belt-shaped film to the medium tank 1, a cutter 17 presses the working board 16 along the periphery of the medium tank 1 as shown by the arrows 16 in
As described above, the polymer film 2 is cut from the winding body 12 by means of the cutter 17 so as to be a required shape. However, as shown in
As shown in
The ultrasonic probe 3 disposed in the medium tank 1 is configured to move and scan the horizontal plane on the basis of the design CAD data of the substrate 6 by an operation controlling unit, so as to automatically inspect the total inspection range of the inspection portion 8.
In the ultrasonic inspection process shown in
The hole 23 through which the air C is injected is preferably positioned higher than a water surface 24 of the water 5 injected into the medium tank 1 in the process of
In this embodiment, a bottom portion 25 inwardly extending from the periphery is formed in the edge of the medium tank 1 to which the polymer film 2 is held. Accordingly, it is possible to increase the contact area between the polymer film 2 and the medium tank 1, and more reliably stick and hold the polymer film 2. Only this point is different from the above-described embodiments.
In this embodiment, a concave portion 27 is formed in advance in the edge of the medium tank 1. Accordingly, even when a different component 26 is mounted to be adjacent to the inspection portion 8, the polymer film 2 can closely adhere to the inspection portion 8.
In such constitution, even when the mounting density of the substrate 6 is high, the substrate 6 can be inspected.
The material of the edge of the medium tank 1 to which the polymer film 2 is held is not mentioned in the above-described embodiments. However, in this (fifth embodiment), an elastic body 28 having an elastic coefficient higher than that of the medium tank 1 is attached to the edge of the medium tank 1 in advance.
In such constitution, the adhesion between the medium tank 1 and the polymer film 2 increases.
In
Specifically, the bottom surface opening of the medium tank 1 is closed with a polymer film 2 to hermetically seal the medium tank 1, the holes 30 are depressurized (A) to stick the polymer film 2 to the bottom surface opening of the medium tank 1, the water 5 is injected so as to immerse at least the distal end of the ultrasonic probe, the inside of the medium tank 1 is pressurized further in a state where the polymer film comes into contact with the inspection portion 8, and the ultrasonic wave transmitted from the ultrasonic probe and reflected by the inspection object is received by the ultrasonic probe for the inspection.
As shown in
In the ultrasonic inspection device shown in
In the ultrasonic inspection device shown in
In such constitution, since the inspection accuracy can be improved and the process of attaching/removing the ultrasonic inspection units can be removed, the inspection efficiency can be considered to be improved.
In the above-described embodiments, the inspection target substrate 6 is moved to the ultrasonic inspection unit in which the ultrasonic probe is disposed so as to obtain the inspection state. However, the ultrasonic inspection unit in which the ultrasonic probe is disposed can be moved to the inspection target substrate 6 so as to obtain the inspection state. In this manner, since the inspection state can be obtained by moving both of the unit and the inspection target to be close to each other, in addition to the operation program for obtaining the inspection state by moving one of the inspection target and the unit to the other, the inspection object and the medium tank can be relatively moved to bring the inspection object into contact with the polymer film, and the ultrasonic wave transmitted from the ultrasonic probe and reflected by the inspection object can be received by the ultrasonic probe for the inspection.
In the ultrasonic inspection method shown in FIGS. 1(a) to 1(d), the pressure of the inside 4 of the medium tank 1 is reduced as shown in
Specifically, in
In this state, by lifting the stage 7 on which the inspection target substrate 6 is placed in a direction indicated by the arrow B as shown in FIGS. 11(c) to 11(d), the alcohol 33 initially collected in the center of the polymer film 2 comes into contact with the center of the upper surface of the inspection portion 8, and the unevenness (not shown) of the center of the upper surface of the inspection portion 8 is wet with the alcohol 33. Accordingly, the alcohol 33 is introduced to the concave portion of the central portion of the upper surface of the inspection portion 8. With the lifting of the stage 7, since the polymer film 2 comes into contact with the upper surface of the inspection portion 8 from the center toward the exterior, and the remaining alcohol 33 supplied to the central portion of the upper surface of the inspection portion 8 spreads toward the exterior of the inspection portion 8, the concave portion of the inspection portion 8 is filled with the alcohol 33, and the inspection portion 8 closely adheres to the polymer film 2 in a state where there is no air between the inspection portion 8 and the polymer film 2. The remaining alcohol 33 eliminated between the inspection portion 8 and the polymer film 2 vaporizes so that the alcohol 33 does not exist on the substrate 6. Accordingly, there is no effect on electrical performance.
As described above, even when the surface of the inspection portion 8 is uneven, the polymer film 2 closely adheres to the inspection portion 8 by introducing the alcohol 33 to the inspection portion 8. Accordingly, the inspection accuracy is improved as compared with a case in which the air remains in the concave portion of the surface of the inspection portion 8.
As the alcohol 33, isopropyl alcohol, ethanol and methanol can be used.
In FIGS. 11(a) to 11(d), the polymer film 2 attached to the medium tank 1 is socked in the alcohol 33 in
In the (eighth embodiment) shown in
The invention can realize accurate ultrasonic inspection without wetting an inspection object in a production process. Accordingly, the invention can be used in in-line inspection for an electronic substrate mounting a variety of semiconductor devices.
Number | Date | Country | Kind |
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2005-006956 | Jan 2005 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2006/300209 | 1/11/2006 | WO | 6/27/2007 |