Patent Application
20070069744
The present invention relates to a technique for manufacturing a probe card used for an electrical inspection of an electric circuit and an inspection apparatus using the probe card.
For an electrical inspection of electric circuits of semiconductor chips, substrates used for liquid crystal displays or the like, conventionally, a probe card has been used, which inputs a signal and detects an output signal by bringing probes into contact with electrode pads of an electric circuit. In a general-type probe card provided are a lot of cantilever-type probes extending in a slanting direction from a main body of the probe card. When there are a lot of electrode pads in a unit area to be inspected, a probe card in which tips of probes are concentrated on a very small region is used.
When an insulating film such as an oxide film is present on an electrode pad in an electric circuit, sometimes a technique is used in which a tip of a probe pressed against the electrode pad is shifted to scrape off a surface of the electrode pad and continuity between the probe and the electrode pad is thereby established.
On the other hand, as a probe card not having cantilever-type probes, proposed is a probe card using bumps which is obtained by growing nickel plating as probes, as disclosed in Japanese Patent Application Laid Open Gazette No. 9-5355.
In a probe card, it is necessary to arrange a lot of fine probes at microscopic intervals in a very small range. In recent, with high definition of objects to be inspected, since the number of probes to be needed in a unit area increases and higher positional accuracy for the probes is required, it becomes difficult to perform an inspection or the cost for an inspection apparatus becomes higher if a conventional cantilever-type probe card is used.
Further, when the number of probes increases, in a case of the probe card shown in the Japanese Patent Application Laid Open Gazette No. 9-5355, a large pressing force is needed to surely establish continuity between a lot of probes and electrode pads and this possibly produces an effect on performance of an electric circuit to be inspected.
The present invention is intended for a board for probe card used for an electrical inspection of an electric circuit. The board for probe card comprises a base board, and three-dimensional structures each having a plurality of blocks piled up on the base board, the plurality of blocks being formed of photosensitive material.
In the board for probe card of the present invention, it is possible to easily provide a lot of three-dimensional structures for probe each of which has the piled-up blocks of photosensitive material.
According to an aspect of the present invention, in the board for probe card, each of the three-dimensional structures comprises a flexible part which bends to allow a portion farthest away from the base board to be moved toward the base board. With the probe card manufactured by using the board for probe card, it is possible to surely establish a contact between an object to be inspected and probes.
Preferably, the three-dimensional structure comprises a plurality of protruding parts which protrude from the base board, and a connecting part for connecting tips of the plurality of protruding parts. Further preferably, the plurality of protruding parts protrude from three portions which are nonlinearly arranged on the base board.
According to the present invention, the further processed board for probe card further comprises a conductive film for coating each of the three-dimensional structures. Preferably, the conductive film is a metal coating film formed by electroless plating.
The present invention is also intended for an inspection apparatus for performing an electrical inspection of an electric circuit. The inspection apparatus comprises a probe card on which probes are provided, a pressing mechanism for pressing the probes toward an electric circuit to be inspected, and an inspection part for electrically inspecting the electric circuit through the probes, and in the inspection apparatus, the probe card comprises a base board, three-dimensional structures each having a plurality of blocks formed of photosensitive material and piled up on the base board, and conductive films for coating the three-dimensional structures, respectively.
By using the inspection apparatus of the present invention, it is possible to surely establish a contact between a lot of probes and an electric circuit by using microscopic three-dimensional structures with a small pressing force. Further, since the probe card in which a lot of probes are arranged with high precision is obtained by using photosensitive material, the inspection apparatus is suitable especially for inspection of a fine electric circuit.
The present invention is further intended for a photo-fabrication apparatus for forming three-dimensional structures for probes used for an electrical inspection of an electric circuit. The photo-fabrication apparatus comprises a holding part for holding a base board, a feeding part for feeding liquid photosensitive material onto the base board, a squeegee for forming a layer of photosensitive material which is fed onto the base board on an existing layer and pushing redundant photosensitive material out into a region outside the existing layer through movement relative to the base board in a predetermined direction along a main surface of the base board, a moving mechanism for moving the squeegee relatively to the base board in the predetermined direction, a spacing change mechanism for changing a spacing between the squeegee and the holding part, and a light emitting part for emitting light to a region which is determined in advance with respect to a layer of photosensitive material formed through movement of the squeegee.
With the photo-fabrication apparatus of the present invention, it is possible to easily form a lot of three-dimensional structures for probe. Further, since the redundant photosensitive material is pushed out into a region outside the existing layer, it is not necessary to provide any resin bath and it is thereby possible to ensure size reduction of the photo-fabrication apparatus.
Preferably, the layer of photosensitive material has a thickness of 20 μm or less. Further preferably, the light emitting part comprises a spatial light modulator for generating a spatially-modulated light beam. It is therefore possible to perform light emission at high speed with high accuracy.
According to an aspect of the present invention, the photo-fabrication apparatus further comprises a control part for controlling the quantity of light to be emitted to each microscopic region on a layer of photosensitive material, and the control part comprises a storage part for storing shape data of a three-dimensional structure formed on a board and a table substantially indicating a relation between the quantity of light to be emitted onto a microscopic region on a layer of photosensitive material and a depth of exposure of the layer, and an operation part for obtaining the quantity of light to be emitted for each microscopic region on each layer of photosensitive material piled up to form the three-dimensional structure on the basis of the shape data and the table.
It is thereby possible to form a three-dimensional structure having a smooth shape.
The present invention is still further intended for a photo-fabrication method for forming three-dimensional structures for probes used for an electrical inspection of an electric circuit. The photo-fabrication method comprises a feeding step for feeding liquid photosensitive material onto a base board, a layer formation step for forming a layer of the photosensitive material on the base board by moving a squeegee relatively to the base board in a predetermined direction along a main surface of the base board, a light emitting step for emitting light to a region which is determined in advance with respect to the layer of photosensitive material, and a repeating step for repeating the feeding step, the layer formation step and the light emitting step a plurality of times, and in the photo-fabrication method, the layer of photosensitive material is formed on an existing layer and redundant photosensitive material is pushed out into a region outside the existing layer in the layer formation step included in the repeating step.
In the photo-fabrication method of the present invention, it is not necessary to provide any resin bath since the redundant photosensitive material is pushed out into a region outside the existing layer.
These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
The photo-fabrication apparatus 1 is an apparatus for forming three-dimensional microstructures for probe used for an electrical inspection of an electric circuit. The photo-fabrication apparatus 1 has a base 11 which is horizontally disposed, a stage 2 for holding a base board 9 which is a base for a board for probe card, a feeding part 3 for feeding photosensitive material, i.e., liquid photocurable resin, onto the base board 9, a layer forming part 4 for forming a layer having a predetermined thickness by smoothly spreading the photosensitive material fed on the base board 9, a light emitting part 5 for emitting a light beam to the layer of photosensitive material formed on the base board 9, a stage moving mechanism 6 for moving the stage 2 relatively to the light emitting part 5, a stage up-and-down moving mechanism 7 for vertically moving the stage 2 and a camera 58 for picking up an image of an alignment mark on the base board 9.
The feeding part 3, the layer forming part 4, the light emitting part 5, stage moving mechanism 6, stage up-and-down moving mechanism 7 and the camera 58 are connected to a control part 8, and the control part 8 controls these constituent elements to form microstructures for probe on the base board 9. The control part 8 has a storage part 81 for storing a variety of data and an operation part 82 for performing a variety of arithmetic operations.
The feeding part 3 has a nozzle 31 for dropping the photosensitive material onto the base board 9 for feeding, an arm 32 for supporting the nozzle 31 at a position higher than that of the stage 2 and a column 33 vertically provided on the base 11, for supporting the arm 32 horizontally with respect to the base 11. The arm 32 is rotatably supported at an upper portion of the column 33 and the nozzle 31 is attached to a tip of the arm 32. When the arm 32 is rotated by a not-shown motor, the nozzle 31 becomes movable between a position above the base board 9 and a position away from the base board 9.
The nozzle 31 is connected to a pump 313 through a pipe 311 and a valve 312, and the pump 313 is connected to a material tank 316 through a pipe 314 and a valve 315. The control part 8 controls the pump 313 and the valves 312 and 315 to feed a predetermined amount of photosensitive material onto the base board 9 from the nozzle 31.
The layer forming part 4 has a plate-like squeegee 41 provided orthogonally to a main surface of the base board 9 (and elongating in an X direction of
The light emitting part 5 has a light source 51 provided with a semiconductor laser for emitting light (having a wavelength of, e.g., approximate 300 or 400 nm) and a micromirror array 54 (e.g., a DMD (Digital micromirror device), and hereinafter, referred to as a “DMD 54”) in which a plurality of micromirrors are two-dimensionally arranged, and a light beam from the light source 51 is spatially modulated by the DMD 54 and emitted onto the base board 9.
Specifically, a light beam emitted from optical fiber bundle 511 connected to the light source 51 is guided by an optical system 52 to the DMD 54 through a shutter 53. In the DMD 54, a light beam formed of only light reflected on some of the micromirrors which have a predetermined orientation (the orientation corresponding to an ON state in the following discussion on light emission by the DMD 54) is led out. The light beam from the DMD 54 is guided to a mirror 56 through a group of lenses 55 and the light beam reflected on the mirror 56 is guided by an objective lens 57 to the base board 9.
The stage moving mechanism 6 has an X-direction moving mechanism 61 for moving the stage 2 in the X direction and a Y-direction moving mechanism 62 for moving the stage 2 in the Y direction. The X-direction moving mechanism 61 has a motor 611, guide rails 612 and a ball screw (not shown), and with rotation of the ball screw by the motor 611, the Y-direction moving mechanism 62 moves along the guide rails 612 in the X direction. The Y-direction moving mechanism 62 has the same constitution as the X-direction moving mechanism 61, and with rotation of a ball screw (not shown) by a motor 621, the stage 2 is moved along guide rails 622 in the Y direction. Further, the stage moving mechanism 6 is supported by the stage up-and-down moving mechanism 7 on the base 11, and when the stage up-and-down moving mechanism 7 is driven, the stage 2 is moved in a Z direction and a spacing between the squeegee 41 and the stage 2 is changed.
In controlling the DMD 54, data (hereinafter, referred to as “cell data”) indicating ON or OFF for each micromirror 541 is transmitted to the DMD 54 from the control part 8 of
In other words, a light microbeam incident on a micromirror 541 which is brought into the ON state is reflected to the group of lenses 55 and guided to a corresponding microscopic region 542 on the base board 9. A light microbeam incident on a micromirror 541 which is brought into the OFF state is reflected to a predetermined position different from the group of lenses 55 and not guided to a corresponding microscopic region 542 on the base board 9.
In the photo-fabrication apparatus 1, by controlling the DMD 54, it is possible to change the quantity of light to be emitted for each microscopic region 542. Specifically, the control part 8 transmits a reset pulse to the DMD 54 a predetermined times during a given time period to accurately control the number of ON states of each micromirror 541 (which corresponds to a cumulative time where the micromirror 541 is in the ON state), and thus the quantity of light to be emitted to each microscopic region 542 is controlled (in other words, a gray-scale (or multi-level) control is performed). It is not necessary, however, to generate the reset pulse at regular intervals, and for example, a unit time is divided into time frames of 1:2:4:8:16 and a reset pulse is transmitted one time at an initial point of each time frame, and thus a gray-scale control (in the above case, into 32 levels) is performed.
Hereafter, formation of microstructures for probe by the photo-fabrication apparatus 1 will be discussed, and discussion will be made, first, on an operation without gray-scale control of the DMD 54, referring to
In formation of the microstructures, first, data (hereinafter, referred to as “cross-sectional data”) 811 indicating a cross-sectional shape in a case of slicing a lot of three-dimensional microstructures to be formed by a given thickness (hereinafter, referred to as “slice width”) in a direction of height (the Z direction of
Subsequently, the camera 58, receiving a signal from the control part 8, picks up an image of an alignment mark on the base board 9 and transmits image data to the control part 8. The control part 8 detects a position of the base board 9 relative to the objective lens 57 (in other words, a distance between a reference position on the base board 9 and the objective lens 57 in the X and Y directions) on the basis of the image data and controls the stage moving mechanism 6 to move the base board 9 to a predetermined position on the basis of the detected result (Step S12).
Further, the control part 8 detects a spacing between the squeegee 41 and the base board 9 (in other words, a distance between a lower edge of the squeegee 41 and the main surface of the base board 9, and hereinafter referred to as a “squeegee gap”) on the basis of information on focusing at the time when the camera 58 acquires the image data and controls the stage up-and-down moving mechanism 7 to adjust the squeegee gap to be the slice width on the basis of the detected result and information on the slice width which is included in the cross-sectional data 811 (Step S113).
When adjustment of the squeegee gap (Step S13) is completed, first, the arm 32 rotates to move the nozzle 31 above the base board 9 as shown in
Next, as shown in
Since the photosensitive material fed onto the base board 9 has high viscosity and mounted on the base board 9 higher than the squeegee gap, when the squeegee 41 moves in the Y direction along the main surface of the base board 9 with a spacing between the lower edge thereof and the main surface of the base board 9 kept constant, the photosensitive material is smoothly spread (i.e., squeegeed) on the base board 9 to have a thickness equal to the squeegee gap and a first material layer 91 of photosensitive material is thereby formed on the base board 9 as shown in
When formation of the first material layer 91 is completed, next, the control part 8 controls the light source 51 to start emission of light beam and controls the DMD 54 (Step S16), to thereby emit the light beam onto the material layer 91. Specifically, the control part 8 writes cell data into memory cells corresponding to the micromirrors 541 in the DMD 54, and when the control part 8 transmits a reset pulse to the DMD 54, the micromirrors 541 take orientations in accordance with the data in the corresponding memory cells, and the light beam emitted from the light source 51 are thereby spatially modulated by the DMD 54 and thus emission of light to the microscopic regions 542 is controlled.
The light from the light emitting part 5 is thereby emitted, as shown in the lower view of
When a range where the microstructures are formed is wider than a range of light emission by the DMD 54, the stage moving mechanism 6 of
When formation of the resin blocks in accordance with one cross-sectional data 811 is completed, the control part 8 checks if formation of the whole microstructures is completed and then the operation flow goes back to Step S13 where the adjustment of squeegee gap is performed (Step S18) and formation of the second material layer is started.
In formation of the second resin block 910 from the base board 9, first, the stage up-and-down moving mechanism 7 is driven to move the stage 2 downward by the slice width so that the squeegee gap should be made twice as large as the slice width (Step S13). A distance between the lower edge of the squeegee 41 and a surface of the first material layer 91 thereby becomes equal to the slice width.
Next, as shown in
When formation of the second material layer 92 is completed, light from the light emitting part 5 is emitted to specific microscopic regions 542b (hatched regions in the lower view of
Then, operations of increasing the squeegee gap by slice width to form the material layer and emitting the spatially-modulated light beam (Steps S13 to S17) are repeated at required times (Step S18), and as shown in
In formation of a new material layer on the base board 9 or the existing material layer, it is proved that a thickness of the material layer can be 20 μm or less when the viscosity of the photosensitive material is set 1500 cP (centipoise) or more (preferably, about 2000 cP). A height of the microstructure 90 for probe is 2 mm or less at the maximum from the main surface of the base board 9. Since the material layer is formed on a microscopic region, no bath for storing the photosensitive material is needed in the photo-fabrication apparatus 1 as discussed above and the material layer can be stably formed only if the redundant photosensitive material is pushed out into a region outside the existing material layer through movement of the squeegee 41.
As shown in
The two protruding parts 901 protrude so that near the base board 9, the tips thereof should become apart from each other as the distance from the base board 9 becomes larger, and the width of the microstructure 90 gets to the maximum at a position away from the base board 9 to some degree. For this reason, when the tip of the microstructure 90 after removal of the unnecessary photosensitive material in the later process receives a force toward the base board 9, the microstructure 90 bends with portions at the maximum width and around it serving as flexible parts 903 which are distorted with respect to a direction orthogonal to the base board 9 and the tip can easily move toward the base board 9. Since the microstructure 90 has such an elastic structure (a structure with spring properties), it is possible to establish an excellent contact between the probes and an electric circuit on a semiconductor substrate in an electrical inspection for the electric circuit discussed later. It is preferably that a spring constant of the microstructure 90 should be about 102 to 105 N/m for excellent contact between the probes and the electric circuit.
Next, discussion will be made on an operation of the photo-fabrication apparatus 1 in the case where the gray-scale control of the DMD 54 is performed. When the gray-scale control is performed, in the photo-fabrication apparatus 1, a conversion table 812 indicating the quantity of light to be emitted to one microscopic region 542 on the material layer and a height of a remaining resin block (a depth of exposure) after removal of the unnecessary photosensitive material is produced in advance and stored in the storage part 81 (see
The cross-sectional data in the case of not performing the gray-scale control for the DMD 54, which is inputted to the control part 8 in Step S11 of
In the photo-fabrication apparatus 1, on the basis of the extended cross-sectional data, not only whether light emission to each microscopic region 542 on each material layer should be performed or not but also the quantity of light to be emitted are controlled. Specifically, on the basis of the extended cross-sectional data and the conversion table 812, the quantity of light to be emitted to each microscopic region 542 on each of the material layers is obtained by the operation part 82 and the cell data corresponding to each of reset pulses generated during a given time period is generated so that the quantity of light to be emitted should signify cumulative time of light emission.
Subsequently, like in the case of not performing the gray-scale control, adjustment of a position of the base board 9 relative to the objective lens 57 is performed (Step S12), and adjustment of the squeegee gap is performed (Step S13). Then, the photosensitive material is fed onto the base board 9 (Step S14), and the squeegee 41 smoothly spreads the photosensitive material on the base board 9 to form a material layer (Step S15).
When formation of the material layer is completed, the control part 8 controls the light source 51 to start emission of light beam and controls the DMD 54 (Step S16), to thereby start emission of the light subjected to the gray-scale control. In other words, write of the cell data and transmission of the reset pulse to the memory cell corresponding to each micromirror 541 in the DMD 54 from the control part 8 are repeated at high speed and the quantity of light to be emitted to each microscopic region 542 is accurately controlled.
When a predetermined number of transmissions of the reset pulses are finished, emission of the light beam from the light source 51 is stopped (Step S17), and formation of resin blocks in accordance with the extended cross-sectional data for one layer is completed. After that, like in the case of not performing the gray-scale control, the control part 8 checks if formation of the whole microstructure is completed (Step S18), and if not completed, adjustment of the squeegee gap (Step S13), feeding of the photosensitive material (Step S14), formation of the material layer (Step S15) and light emission (Steps S16 and S17) are repeated. When formation of all the resin blocks is completed, the repeating operation is finished (Step S18).
With this gray-scale control, as shown in the upper view of
Actually, however, it is considered that the smoother shape of the microstructure is obtained not because a hardened portion of photosensitive material becomes thinner by the gray-scale control but in removal of unhardened photosensitive material in the later process, part of incomplete hardened portion and a sufficiently hardened portion are united, remaining, to be the smooth-shaped microstructure 90 as shown in
Through the above operations, in the photo-fabrication apparatus 1 of the first preferred embodiment, a plurality of microstructures 90 for fine probe, each consisting of a plurality of resin blocks which are piled up and having a predetermined three-dimensional shape, are stably formed on the electrode pads on the base board 9. Since the spatially-modulated light beam (i.e., a flux of many modulated light microbeams) is generated by the DMD 54 and emitted to the material layer at high speed with high positional accuracy, a lot of microstructures for probe can be formed and arranged at high speed with high positional accuracy.
Further, the photo-fabrication apparatus 1 does not need a resin bath, unlike a conventional and general photo-fabrication apparatus using light, since it adopts the technique to form microstructures in which the photosensitive material is fed directly onto the base board 9 and the photosensitive material unnecessary for formation of the material layer is pushed out into a region outside an existing material layer, and it is therefore possible to achieve size reduction of the photo-fabrication apparatus 1.
Since the base board 9 on which the microstructures 90 are formed in the material layers by the photo-fabrication apparatus 1 is cleared of the unhardened resin in the subsequent process (for example, the base board 9 is immersed in developer and the photosensitive material to which no light is emitted is solved therein and removed), it is possible to easily obtain a board for probe card comprising a lot of microstructures 90 each formed of resin blocks piled up on the main surface of the base board 9.
As shown in
When the plating is finished, as shown in
A probe card is manufactured by bonding the metal-plated board to electrodes of a main board which is separately prepared through wire-bonding. The bonding of the metal-plated board to the main board may be performed by a method using bumps or the like.
As discussed above, a metal-plated board 10a is attached to a main board 112 in the probe card 110 and the probe card 110 is attached to the probe head 120 so that the probes 111 on the metal-plated board 10a face a side of the semiconductor substrate 150 (the (−Z) side of
The probe head 120 has a mount part 121 on which the probe card 110 is mounted and a pressing mechanism 122 for moving the mount part 121 in the Z direction of
When the inspection apparatus 100 inspects one electric circuit 151, first, a predetermined electric circuit(s) 151 on the semiconductor substrate 150 is moved directly below the probe card 110 and with control by the control part 140, the pressing mechanism 122 moves the probe card 110 downward to press the probes 111 against the electric circuit 151.
When the probe card 110 comes into contact with the electric circuit 151, an electrical signal for inspection is outputted from the inspection part 130, the inspection signal is inputted to (the electrode pads 97 of) the electric circuit 151 through the corresponding probes 111 and output signals from other electrode pads 97 are inputted to the inspection part 130 through the probes 111 for detection. In a case of inspection only on conductivity of a predetermined portion of the electric circuit 151, input and detection of signals are performed with two probes 111 made a pair. In a case of advanced inspection, inspection signals from a plurality of probes 111 are inputted and an output signal from the electric circuit 151 is detected by at least one other probe 111. Then, the inspection part 130 judges pass/fail of the electric circuit 151 on the basis of the detected signal.
In a semiconductor substrate, generally, the electrode pads through which the electric circuit 151 and the probes 111 are in contact with each other are formed of aluminum (Al) and their surfaces are apt to be covered with insulative oxide films. The inspection apparatus 100 achieves an excellent continuity between the probes 111 and the electric circuit 151 with high voltage across the probes 111 and the electrode pads to ensure dielectric breakdown of the oxide films on the electrode pads. Conventionally, a technique of slightly scraping off the oxide film on the surface of the electrode pad with the probe itself to establish continuity between the probe and the electrode pad has been adopted. On the other hand, in the inspection apparatus 100, since such a technique is not adopted and therefore no chip of the oxide film is deposited on the tips of the probes 111, it is possible to reduce works for maintenance of the probes 111 and achieve improvement of inspection efficiency.
Thus, in the inspection apparatus 100, with the probe card 110 using the microstructures formed by the photo-fabrication apparatus 1, it is possible to surely establish contact between the probes 111 and the electric circuit 151. Especially, since the photo-fabrication apparatus 1 allows a lot of microstructures for fine probe to be arranged in a microscopic area with high positional accuracy, the probe card 110 is suitable for electrical inspection of electric circuits on semiconductor substrates (semiconductor chips).
With such a construction, in the microstructure 90a, portions at the largest width (horizontally protruding portion) serve flexible parts 903a which is easily elastically deformed and a portion farthest away from the base board 9 can be easily moved toward the base board 9. As a result, a probe manufactured on the basis of the microstructure 90a, like the probe of
Since the protruding parts 901a are nonlinearly arranged, the probe resists being bent sideward even if it receives a force parallel to the base board 9. Further, in forming the microstructure 90a, the gray-scale control of the DMD 54 may be performed as discussed above.
The light beam emitted from the light source 51 through the optical fiber bundle 511 is modulated by the AOM 52a and goes toward the polygon mirror 54a through the shutter 53. The light beam reflected on the rotating polygon mirror 54a is guided to the mirror 56 through the group of lenses 55. Further, the light beam reflected on the mirror 56 is guided onto the base board 9 through the objective lens 57.
The irradiation position (or microscopic region) of light is moved by the polygon mirror 54a in the main scan direction (the X direction of
Further, the gray-scale control of light beam (control on light intensity in emission to one microscopic region) may be performed on the basis of the extended cross-sectional data discussed earlier.
Though the preferred embodiments of the present invention have been discussed above, the present invention is not limited to the above-discussed preferred embodiments, but allows various variations.
For example, there may be a construction where the squeegee 41 is fixed and the base board 9 held on the stage 2 is moved by the Y-direction moving mechanism 62 in the Y direction of
A collection mechanism may be additionally provided at a side of the stage 2 to collect the redundant photosensitive material which is pushed off into a region outside the existing material layer in the layer formation step.
The light emitting part 5 may be changed as appropriate only if it can form a microscopic light spot on the material layer. For example, a light beam which is spatially modulated by a liquid crystal shutter may be generated, or there may be case where multibeams (light beam subjected to one-dimensional spatial modulation) are generated by individually modulating divided laser beams and deflected by a polygon mirror or a galvanic mirror for scanning.
The conversion table 812 used in the gray-scale control is not necessarily a table directly indicating a relation between the quantity of light to be emitted to one microscopic region 542 and an exposure depth of the material layer (exactly, a thickness of a portion left after removal of the unnecessary photosensitive material) but only has to be a table substantially indicating the relation. For example, the conversion table 812 may be a table or function indicating a relation between a light emission time and an exposure depth, or a table indicating a relation between the number of ON states of the DMD 54 and an exposure depth.
In the photo-fabrication apparatus 1 of the first preferred embodiment, it is possible to perform the gray-scale control while continuously moving the irradiation region. Specifically, by controlling the stage moving mechanism 6 in synchronization with the control of the DMD 54 to transmit the reset pulse to the DMD 54 every time when the irradiation region moves by one microscopic region, the gray-scale control using the number of duplicate light emission can be performed. It is thereby possible to quickly emit light which is substantially subjected to the gray-scale control to a wide region on the material layer.
The shape of the microstructure for probe formed by the photo-fabrication apparatus is not limited to that shown in
The photosensitive material does not necessarily always have to be liquid but may be one which is solidified to some degree after being fed onto the base board 9 and partially subjected to light emission in development of the later process to be left on the base board 9. Further, the photosensitive material is not limited to a negative-type one such as a photocurable resin but may be a positive-type one which is partially subjected to light emission to be removed in development.
If flexibility is scarcely required of the probe, a bench-type microstructure may be formed in which the tips of the two protruding parts 901 orthogonal to the main surface of the base board 9 are connected by a connecting part parallel to the main surface of the base board 9.
While the invention has been shown and described in detail, the foregoing description is in all aspects illustrative and not restrictive. It is therefore understood that numerous modifications and variations can be devised without departing from the scope of the invention.
The present invention can be used for a technique to manufacture a probe card for electrically inspecting fine electric circuits formed on semiconductor substrates (or semiconductor chips), glass substrates used for liquid crystal displays, printed circuit boards or the like, and an inspection apparatus comprising the probe card.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2003-151992 | May 2003 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP04/06569 | 5/10/2004 | WO | 11/22/2005 |
