JP2010069566A - Water jet machining device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water jet machining device including a function to detect the concentration of abrasive grains mixed in machining water. <P>SOLUTION: This water jet machining device includes a workpiece holding means for holding a workpiece and a machining water injection means for injecting the machining water mixed with abrasive grains in the workpiece held with the workpiece holding means. The machining water injection means includes a machining water delivery means for delivering the machining water mixed with the abrasive grains and a nozzle for injecting the machining water delivered from the machining water delivery means. The water jet machining device includes an abrasive grain concentration detection means for detecting the concentration of the abrasive grains mixed in the machining water in a machining water delivery pipe for connecting the machining water delivery means and the nozzle. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a water jet machining apparatus for cutting a workpiece such as a semiconductor wafer by jetting high-pressure machining water.

  In the semiconductor device manufacturing process, circuits such as ICs and LSIs are formed in a large number of regions arranged in a lattice pattern on the surface of a substantially disc-shaped semiconductor wafer, and each region where the circuits are formed is defined on a predetermined street. Each semiconductor chip is manufactured by dicing along a planned cutting line. The semiconductor chip thus divided is packaged and widely used in electric devices such as mobile phones and personal computers.

  Electric devices such as mobile phones and personal computers are required to be lighter and smaller, and a package technology that can reduce the size of a semiconductor chip package called a chip size package (CSP) has been developed. As one of the CSP technologies, a package technology called Quad Flat Non-Lead Package (QFN) has been put into practical use. This packaging technology called QFN is a method in which a plurality of connection terminals corresponding to the connection terminals of the semiconductor chip are formed and a plurality of metal plates such as a copper plate are formed in a grid pattern with division lines divided for each semiconductor chip. Semiconductor chips are arranged in a matrix, and a CSP substrate is formed by integrating a metal plate and a semiconductor chip by a resin portion obtained by molding resin from the back side of the semiconductor chip. The CSP substrate is cut along a division planned line to be divided into individually packaged chip size packages (CSP).

  The CSP substrate is generally cut by a precision cutting device. The cutting apparatus includes a cutting blade having an annular abrasive grain layer, and moves the CSP substrate along the planned division line by rotating the cutting blade along the planned division line of the CSP substrate. Cut and divide into individual chip size packages (CSP). However, when the CSP substrate is cut with a cutting blade, there is a problem that burrs are generated in the connection terminals, and the adjacent connection terminals are short-circuited to deteriorate the quality and reliability of the chip size package (CSP).

In addition, when a workpiece such as a semiconductor wafer is cut by a cutting blade, not only the CSP substrate, there is a problem that fine cutting waste adheres to the surface of the workpiece and is contaminated.
As a cutting technique for solving such a problem in cutting with a cutting blade, high-pressure processing water in which abrasive grains such as silica and garnet are mixed is injected from a nozzle onto the workpiece held by the workpiece holding means. A water jet cutting process for cutting a workpiece has been proposed. (For example, refer to Patent Document 1.)
JP 2005-231000 A

  Thus, there is a problem that it is impossible to confirm whether or not the concentration of the abrasive grains mixed in the processing water is maintained in an appropriate range, and the processing accuracy is not stable.

  This invention is made | formed in view of the said fact, The main technical subject is providing the water jet processing apparatus provided with the function to detect the density | concentration of the abrasive grain mixed in the processing water.

In order to solve the above main technical problem, according to the present invention, a workpiece holding means for holding a workpiece, and a processing water in which abrasive grains are mixed in the workpiece held by the workpiece holding means. A processing water injection means for injecting the processing water, the processing water injection means for sending out the processing water mixed with abrasive grains, and a nozzle for injecting the processing water sent out from the processing water sending means. In a water jet machining apparatus comprising:
Comprising abrasive concentration detecting means for detecting the concentration of abrasive particles mixed in the processing water in the processing water delivery pipe connecting the processing water delivery means and the nozzle;
A water jet machining apparatus is provided.

The abrasive concentration detecting means is based on a light emitting means for emitting detection light in the processed water delivery pipe, a light receiving means disposed opposite to the light emitting means, and a received light amount received by the light receiving means. It comprises control means for determining the concentration of abrasive grains mixed in the processing water.
The control means outputs an error message to the display means when the abrasive grain concentration is not within the allowable range.
In addition, a pair of opening windows provided opposite to each other are formed in the processed water delivery pipe, and sapphire is mounted on each of the pair of opening windows, and light emitting means is disposed on one of the pair of opening windows. The light receiving means is disposed on the other of the pair of opening windows.

  The water jet machining apparatus according to the present invention is configured as described above, and has an abrasive concentration detection means for detecting the concentration of abrasive grains mixed in the machining water in the machining water delivery pipe connecting the machining water delivery means and the nozzle. Since it comprises, it can be confirmed whether the density | concentration of the abrasive grain mixed in the processing water sprayed from a nozzle is maintained in the appropriate range. Therefore, when the operator confirms the concentration of the abrasive grains mixed in the processing water detected by the abrasive concentration detection means, and the concentration of the abrasive grains mixed in the processing water is lower than the lower limit value of the appropriate range. Replenishes abrasive grains, and when the concentration of abrasive grains is higher than the upper limit value of the appropriate range, the concentration of abrasive grains mixed in the processing water can be maintained within the proper range by replenishing water.

  Hereinafter, preferred embodiments of a water jet machining apparatus according to the present invention will be described in more detail with reference to the accompanying drawings.

  FIG. 1 is a perspective view of a main part of a water jet machining apparatus configured according to the present invention. The water jet machining apparatus shown in FIG. 1 includes a stationary base 2, a first movable base 3, a second movable base 4, and a third movable base 5. A pair of guide rails 21, 21 extending in parallel along the direction indicated by the arrow X is provided on the side surface on the near side of the stationary base 2.

  A first movable base 3 is slidably mounted on the stationary base 2 along the pair of guide rails 21 and 21. That is, as shown in FIG. 1, one surface of the first movable base 3 facing the first movable base 3 is fitted to a pair of guide rails 21, 21 provided on the stationary base 2. A pair of guided grooves 31, 31 are provided, and the first movable base 3 is a stationary base by fitting the pair of guided grooves 31, 31 to the pair of guide rails 21, 21. 2 is slidably mounted in a direction indicated by an arrow X along a pair of guide rails 21 and 21. A pair of guide rails 32, 32 extending in parallel with the direction indicated by the arrow Z are provided on the other surface of the first movable base 3. The water jet machining apparatus in the illustrated embodiment is a first for moving the first movable base 3 in the direction indicated by the arrow X along the pair of guide rails 21, 21 provided on the stationary base 2. The moving means 30 is provided. The first moving means 30 includes a male screw rod 301 disposed between the pair of guide rails 21 and 21 in parallel with the guide rail, and a pulse motor 302 for driving the male screw rod 301 to rotate. It is out. The male screw rod 301 is screwed into the female screw 33 provided on the first movable base 3, and one end of the male screw rod 301 is rotatably supported by a bearing member 303 provided on the stationary base 2. The drive shaft of the pulse motor 302 is connected to the other end of the male screw rod 301. Therefore, the first movable base 3 is moved to the pair of guide rails 21, 21 provided on the stationary base 2 by driving the pulse motor 302 forward or backward and driving the male screw rod 301 forward or backward. Along the direction indicated by the arrow X.

  A second movable base 4 is slidably mounted on the first movable base 3 along the pair of guide rails 32 and 32. That is, one side surface of the second movable base 4 facing the first movable base 3 is slidably fitted to a pair of guide rails 32, 32 provided on the first movable base 3. A pair of guided grooves 41, 41 is provided. By fitting the pair of guided grooves 41, 41 to the pair of guide rails 32, 32, the second movable base 4 is the first The movable base 3 is slidably mounted in the direction indicated by the arrow Z along the pair of guide rails 32 and 32. The second movable base 4 includes a pair of guide rails 42 and 42 provided on a side surface perpendicular to the one side surface and extending parallel to the direction indicated by the arrow Y. The water jet machining apparatus in the illustrated embodiment moves the second movable base 4 along the pair of guide rails 32, 32 provided on the first movable base 3 in the direction indicated by the arrow Z. The second moving means 40 is provided. The second moving means 40 includes a male screw rod 401 disposed between the pair of guide rails 32 and 32 in parallel with the guide rail, and a pulse motor 402 for driving the male screw rod 401 to rotate. It is out. The male screw rod 401 is screwed into the female screw 43 provided on the second movable base 4, and one end of the male screw rod 401 is rotatably supported by a bearing member 403 provided on the first movable base 3. Yes. The drive shaft of the pulse motor 402 is connected to the other end of the male screw rod 401. Therefore, by driving the pulse motor 402 forward or backward and driving the male screw rod 401 forward or backward, the second movable base 4 is provided with a pair of guide rails 32 provided on the first movable base 3. , 32 in the direction indicated by the arrow Z.

  A third movable base 5 is slidably mounted on the second movable base 4 along the pair of guide rails 42 and 42. In other words, one side surface of the third movable base 5 facing the second movable base 4 is slidably fitted to a pair of guide rails 42 and 42 provided on the second movable base 4. A pair of guided grooves 51, 51 (only one of the upper side is shown in FIG. 1) is provided, and the pair of guided grooves 51, 51 are formed on the pair of guide rails 42, 42. By fitting, the third movable base 5 is slidably mounted on the second movable base 4 along the pair of guide rails 42 and 42 in the direction indicated by the arrow Y. In the illustrated embodiment, the water jet machining apparatus moves the third movable base 5 in the direction indicated by the arrow Y along the pair of guide rails 42 and 42 provided on the second movable base 4. The third moving means 50 is provided. The third moving means 50 includes a male screw rod 501 disposed between the pair of guide rails 42 and 42 in parallel with the guide rail, and a pulse motor 502 for driving the male screw rod 501 to rotate. It is out. The male screw rod 501 is screwed into a female screw (not shown) provided on the third movable base 5, and one end of the male screw rod 501 is rotatable to a bearing member 503 provided on the second movable base 4. It is supported by. The drive shaft of the pulse motor 502 is connected to the other end of the male screw rod 501. Therefore, by driving the pulse motor 502 forward or backward and driving the male screw rod 501 forward or backward, the third movable base 5 is connected to the pair of guide rails 42 provided on the third movable base 4. , 42 along the direction indicated by the arrow Y.

  On the other surface of the third movable base 5 is mounted a workpiece holding table 6 as a workpiece holding means extending in the direction indicated by the arrow X. The workpiece holding table 6 is formed with a rectangular opening 61, and four positioning pins 62 project from the upper surface around the opening 61. The water jet machining apparatus in the illustrated embodiment includes a catch tank 60 that is disposed below the workpiece holding table 6 and contains water for buffering used machining water, which will be described later.

  The water jet machining apparatus in the illustrated embodiment includes a machining water jetting unit 7 that jets machining water in which abrasive grains are mixed into the workpiece held on the workpiece holding table 6 as the workpiece holding unit described above. It has. The processed water injection means 7 will be described with reference to FIG. The processing water injection means 7 shown in FIG. 2 contains the first high-pressure tank 71a and the second high-pressure tank 71b as processing water sending means for containing and sending the processing water mixed with abrasive grains, and the first high-pressure tank 71b. A high-pressure tank 71a and a nozzle 72 connected to the second high-pressure tank 71b, a high-pressure water supply means 73 for supplying high-pressure water to the first high-pressure tank 71a and the second high-pressure tank 71b, and a first high-pressure tank 71a and the second high-pressure tank 71b are provided with processing water replenishing means 74 for replenishing the processing water mixed with abrasive grains such as silica and garnet.

  The first high-pressure tank 71a and the second high-pressure tank 71b include a first high-pressure water supply pipe 711a and a second high-pressure tank for supplying high-pressure water to the first high-pressure tank 71a and the second high-pressure tank 71b, respectively. A water supply pipe 711b, a first processing water discharge pipe 712a and a second processing water discharge pipe 712b for discharging the processing water in the first high pressure tank 71a and the second high pressure tank 71b, and a first high pressure tank 71a and the second high-pressure tank 71b, the first processing water suction pipe 713a and the second processing water suction pipe 713b for sucking the processing water in the first high-pressure tank 71a and the second high-pressure tank 71b. The 1st processing water supplement pipe 714a and the 2nd processing water supplement pipe 714b which are replenished are arranged. The first high-pressure tank 71a and the second high-pressure tank 71b configured as described above contain the processing water 700 in which abrasive grains are mixed, but the abrasive grains have a higher specific gravity than water, so the first The water settles below the high-pressure tank 71a and the second high-pressure tank 71b, and the water is positioned above the first high-pressure tank 71a and the second high-pressure tank 71b.

  The first high-pressure water supply pipe 711a and the second high-pressure water supply pipe 711b are respectively connected to the first main high-pressure water conduit 751a and the second main high-pressure water conduit 751b, the first high-pressure water on-off valve 79a, and the second high-pressure water on-off valve 79a. The high pressure water on / off valve 79b is connected to the main high pressure water supply means 73. Further, the first processed water discharge pipe 712a and the second processed water discharge pipe 712b are respectively connected to the first processed water discharge pipe 76a and the second processed water discharge pipe 76b through a common processed water discharge pipe 76c. Are connected to the nozzle 72. The first processed water delivery pipe 76a and the second processed water delivery pipe 76b are provided with a first processed water on-off valve 77a and a second processed water on-off valve 77b, respectively. Between the water on-off valve 77a and the second processed water on-off valve 77b and the nozzle 72, the first processed water merging means 78a and the second processed water merging means 78b are disposed. The first processing water on-off valve 77a and the second processing water on-off valve 77b are closed when de-energized (OFF), and are opened when energized (ON). .

  The first machining water merging means 78a and the second machining water merging means 78b include machining water inflow passages 781a and 781b, high pressure water inflow passages 782a and 782b, and machining water outflow passages 783a and 783b, respectively. The high pressure water inflow passages 782a and 782b and the machining water outflow passages 783a and 783b are formed in a straight line, and the processing water inflow passages 781a and 781b are located between the high pressure water inflow passages 782a and 782b and the processing water outflow passages 783a and 783b. The joints 784a and 784b communicate with each other. The first machining water merging means 78a and the second machining water merging means 78b configured as described above are configured such that the machining water inflow passages 781a and 781b have a first machining water delivery pipe 76a and a second machining water delivery pipe, respectively. 76b is connected to the first processing water discharge pipe 712a and the second processing water discharge pipe 712b, and high-pressure water inflow passages 782a and 782b are respectively connected to the first sub-high-pressure water conduit 752a and the second sub-high-pressure water conduit 752b. Is connected to the main high-pressure water supply means 73, and the machining water outflow passages 783a and 783b are connected to the nozzles 72 of the first machining water delivery pipe 76a and the second machining water delivery pipe 76b, respectively.

  The first main high pressure water conduit 751a and the first sub high pressure water conduit 752a are provided with a first high pressure water on / off valve 79a, and the second main high pressure water conduit 751b and the second sub high pressure water conduit 751a. A second high pressure water on / off valve 79b is disposed at 752b. Each of the first high-pressure water on-off valve 79a and the second high-pressure water on-off valve 79b is composed of a 4-port electromagnetic switching valve, which is closed in a deenergized (OFF) state and is energized (ON ) Is configured to open. The high-pressure water supply means 73 includes a water tank 731 and a high-pressure water feed pump 732 that feeds water stored in the water tank 731 at a high pressure.

  The processing water supplement means 74 includes a suction pump 741 and an abrasive filter 742. The suction pump 741 has pipes 743a and 743b connected to the first processing water suction pipe 713a and the second processing water suction pipe 713b. The abrasive filter 742 is connected to the first processing water supplement pipe 714a and the second processing water supplement pipe 714b via pipes 744a and 744b. The pipes 743a and 743b are provided with electromagnetic on-off valves 745a and 745b, respectively, and the pipes 744a and 744b are provided with electromagnetic on-off valves 746a and 746b, respectively. The abrasive filter 742 is connected to the catch tank 60 via a pipe 747.

The water jet machining apparatus in the illustrated embodiment detects the concentration of abrasive grains that are disposed in the common machining water delivery pipe 76c and detect the concentration of abrasive grains mixed in the machining water in the common machining water delivery pipe 76c. Means 80 are provided. The abrasive concentration detecting means 80 will be described with reference to FIG.
The abrasive grain concentration detecting means 80 shown in FIG. 3 includes a light emitting means 801 that emits detection light in a common processed water delivery pipe 76c, and a light receiving means 802 that is disposed to face the light emitting means 801. Yes. That is, a pair of opening windows 761 and 672 provided opposite to each other are formed in the common processed water delivery pipe 76c. Sapphire 803 and 804 are attached to the pair of opening windows 761 and 762, respectively. The light emitting means 801 is arranged on one opening window 761 side, and the light receiving means 802 for receiving the detection light emitted by the light emitting means 801 is arranged on the other opening window 762 side. The light emitting means 801 of the abrasive grain concentration detecting means 80 configured as described above is controlled by a control means described later, and the light receiving means 802 sends a voltage signal corresponding to the received light quantity to the control means described later. The sapphire 803 and 804 are mounted on the pair of opening windows 761 and 762, respectively, by using a material having a hardness higher than the hardness of the abrasive such as silica or garnet mixed in the processing water. This is to prevent wear.

  In the illustrated embodiment, the processing water injection means 7 detects the amount of abrasive grains mixed in the processing water accommodated in the first high pressure tank 71a and the second high pressure tank 71b, respectively. Detection means 81a and second abrasive grain amount detection means 81b are provided. In addition, the 1st abrasive grain amount detection means 81a and the 2nd abrasive grain amount detection means 81b consist of weight scales in embodiment of illustration. Further, the processing water jetting means 7 in the illustrated embodiment is detected from the light receiving means 802 of the abrasive grain concentration detecting means 80, the first abrasive grain amount detecting means 81a, the second abrasive grain amount detecting means 81b, and the like. Based on the signal, the high-pressure water supply pump 732 of the high-pressure water supply means 73, the first high-pressure water on-off valve 79a and the second high-pressure water on-off valve 79b, the suction pump 741 of the machining water replenishing means 74 and the electromagnetic on-off valve 745a. , 745b and electromagnetic open / close valves 746a, 746b, and a control means 9 for controlling the display means 90. The control means 9 also outputs control signals to the pulse motor 302 of the first moving means 30, the pulse motor 402 of the second moving means 40, and the pulse motor 502 of the third moving means 50.

The processing water injection means 7 in the embodiment shown in FIG. 2 is configured as described above, and the operation thereof will be described below.
The control means 9 operates the high-pressure water feed pump 732 that constitutes the high-pressure water supply means 73 of the machining water injection means 7 and energizes (ON) the first high-pressure water on-off valve 79a, and also performs the first machining. The water on-off valve 77a is energized (ON) to open the circuit. When the first high-pressure water on-off valve 79a is energized (ON) to open the circuit, the high-pressure water feed pump 732 and the first high-pressure water conduit 751a communicate with each other, and the high-pressure water passes through the first high-pressure water conduit 751a. It is supplied to the first high-pressure tank 71a. As a result, the inside of the first high-pressure tank 71a becomes a high pressure (for example, 69 MPa), and the processing water 700 accommodated in the first high-pressure tank 71a and mixed with abrasive grains is pushed out through the first processing water discharge pipe 712a. When the first high-pressure water on / off valve 79a is energized (ON) to open the circuit, the high-pressure water feed pump 732 and the first sub-high pressure water conduit 735a communicate with each other, and the high-pressure water is the first sub-high-pressure water conduit. It is supplied to the high-pressure water inflow passage 782a of the first working water confluence means 78a via 752a. As a result, the processed water pushed out from the first processed water discharge pipe 712a and the high-pressure water supplied from the processed water inflow passage 781a merge at the merge portion 784a, and the processed water merged at the merge portion 784a is the first It is sprayed from the nozzle 72 through the processed water delivery pipe 76a (first spraying step). As a result, the workpiece W held on the workpiece holding table 6 is water jet processed. The used processing water subjected to the water jet processing is stored with its momentum eased by the buffering water stored in the catch tank 60.

  As described above, when water jet machining is performed by spraying the processing water 700 accommodated in the first high-pressure tank 71a from the nozzle 72 and mixed with abrasive grains, it is accommodated in the first high-pressure tank 71a and mixed into the processing water. The amount of abrasive grains is reduced. When the amount of abrasive grains mixed in the processing water is equal to or less than the first predetermined value, the processing efficiency is lowered. Therefore, in the illustrated embodiment, the weight of the processing water stored in the first high-pressure tank 71 a is measured by the abrasive grain amount detection means 81 a and the detection signal is sent to the control means 9. That is, since the specific gravity of the abrasive grains is larger than that of water, the weight of the processing water stored in the first high-pressure tank 71a is reduced when the number of abrasive grains is reduced even if the amount of water is the same. And the control means 9 will be the 1st, if the weight of the processing water accommodated in the 1st high pressure tank 71a becomes below 1st predetermined value based on the detection signal from the abrasive grain amount detection means 81a. The high pressure water on / off valve 79a and the first machining water on / off valve 77a are de-energized (OFF), and the second high pressure water on / off valve 79b and the first machining water on / off valve 77b are energized (ON).

  When the first high-pressure water on / off valve 79a is de-energized (OFF) and the second high-pressure water on-off valve 79b is energized (ON) in this way, the high-pressure water feed pump 732 and the second high-pressure water conduit 751b are connected. In communication, high-pressure water is supplied to the second high-pressure tank 71b via the second high-pressure water conduit 751b. As a result, the second high-pressure tank 71b has a high pressure (for example, 69 MPa), and the processing water 700 contained in the second high-pressure tank 71b and mixed with abrasive grains is pushed out through the second processing water discharge pipe 712b. On the other hand, when the second high pressure water on / off valve 79b is energized (ON) to open the circuit, the high pressure water feed pump 732 and the second sub high pressure water conduit 752b communicate with each other, and the high pressure water is supplied to the second sub high pressure water conduit. It is supplied to the high-pressure water inflow passage 782b of the second working water merging means 78b via 752b. As a result, the machining water pushed out from the second machining water discharge pipe 712b and the high-pressure water supplied from the machining water inflow passage 781b merge at the merge portion 784b, and the machining water merged at the merge portion 784b becomes the second It is sprayed from the nozzle 72 through the processed water delivery pipe 76b (second spraying step). As a result, the workpiece W held on the workpiece holding table 6 is water jet processed. The used processing water subjected to the water jet processing is stored with its momentum eased by the buffering water stored in the catch tank 60.

  During the second injection step, the control means 9 operates the suction pump 741 of the machining water replenishment means 74 and energizes (ON) the electromagnetic on-off valve 745a and the electromagnetic on-off valve 746a. Let the circuit open. As a result, water in the upper portion of the first high-pressure tank 71a is sucked through the processed water suction pipe 713a. Accordingly, since the inside of the first high-pressure tank 71a becomes a negative pressure, the processing water accommodated in the catch tank 60 and mixed with abrasive grains passes through the pipe 747, the abrasive filter 742, the pipe 744a, and the processing water supply pipe 714a. The first high-pressure tank 71a is replenished (first processing water replenishment step). In the first process water replenishment step, if the milled material generated by the water jet process is mixed in the process water mixed with the abrasive grains stored in the catch tank 60, the abrasive grains Only the processing water collected by the filter 743 and mixed with abrasive grains is replenished. In the first process water replenishment step, the weight of the process water stored in the first high-pressure tank 71a is measured by the abrasive grain amount detection means 81a, and the detection signal is sent to the control means 9. Yes. And the control means 9 is the 2nd predetermined value whose weight of the processing water accommodated in the 1st high pressure tank 71a is higher by a predetermined amount than the said 1st predetermined value based on the detection signal from the abrasive grain amount detection means 81a. If it becomes above, it will be judged that the required amount of abrasive grains was mixed in the processing water stored in the first high-pressure tank 71a, and the operation of the suction pump 741 was stopped and the electromagnetic on-off valve 745a and the electromagnetic on-off valve 746a were turned on. De-energize (OFF) and close. That is, the first high-pressure tank 71a is always saturated with water and abrasive grains, but the weight increases when abrasive grains having a specific gravity greater than that of water are supplied.

If the second injection step described above is performed and the amount of abrasive particles mixed in the processing water stored in the second high-pressure tank 71b is reduced below the first predetermined value, the amount of abrasive particles Based on the detection signal from the detection means 81b, the control means 9 de-energizes (turns off) the second high-pressure water on-off valve 79b and the second processed water on-off valve 77b, and the first high-pressure water on-off valve 79a and the second high-pressure water on-off valve 79a. The first injection step is performed by energizing (turning on) the one processing water on-off valve 77a.
During the first injection step, the control means 9 operates the suction pump 741 of the processing water replenishing means 74 and energizes (ON) the electromagnetic on-off valve 745b and the electromagnetic on-off valve 746b to open the circuit. Let me. As a result, the water in the upper part of the second high-pressure tank 71b is sucked through the processed water suction pipe 713b. Accordingly, since the inside of the second high-pressure tank 71b becomes a negative pressure, the processing water accommodated in the catch tank 60 and mixed with abrasive grains passes through the pipe 747, the abrasive filter 742, the pipe 744b, and the processing water supply pipe 714b. The second high-pressure tank 71b is replenished (second processing water replenishment step). In the second process water replenishment step, if the milled material generated by the water jet process is mixed in the process water mixed with the abrasive grains stored in the catch tank 60, the abrasive grains Only the processing water collected by the filter 743 and mixed with abrasive grains is replenished. In the second process water replenishment step, the weight of the process water stored in the second high-pressure tank 71b is measured by the abrasive grain amount detection means 81b, and the detection signal is sent to the control means 9. Yes. And the control means 9 is the 2nd predetermined value whose weight of the processing water accommodated in the 2nd high-pressure tank 71b is predetermined amount higher than the said 1st predetermined value based on the detection signal from the abrasive grain amount detection means 81b. If it becomes above, it will be judged that the required amount of abrasive grains was mixed in the processing water stored in the second high-pressure tank 71b, the operation of the suction pump 741 was stopped, and the electromagnetic on-off valve 745b and the electromagnetic on-off valve 746b were turned on. De-energize (OFF) and close. That is, the second high-pressure tank 71b is always saturated with water and abrasive grains, but the weight increases when abrasive grains having a specific gravity greater than that of water are supplied.
As described above, the first injection process, the first process water supplement process, the second injection process, and the second process water supplement process are alternately and continuously performed.

  While repeatedly performing the first injection process, the first process water replenishment process, the second injection process, and the second process water replenishment process described above, the process water is mixed into the process water injected from the nozzle 72. The concentration of abrasive grains changes. If the concentration of abrasive grains mixed in the processing water changes and the concentration deviates from an appropriate range, there is a problem that processing accuracy is not stable. In view of this, the working water jetting means 7 in the illustrated embodiment operates the abrasive concentration detecting means 80 to mix the abrasive grains mixed in the working water flowing through the common working water delivery pipe 76c connected to the nozzle 72. The concentration of is detected. That is, the control unit 9 operates the light emitting unit 801 to emit detection light, and inputs a detection signal from the light receiving unit 802 that has received the detection light that has passed through the processing water in the common processing water delivery pipe 76c. ing. Since the processing water in the common processing water delivery pipe 76c has a large amount of detection light transmitted when the concentration of the abrasive grains mixed in is low, the amount of light received by the light receiving means 802 increases and the mixed abrasive grains. When the density of the light is high, the amount of detection light transmitted is small, so the amount of light received by the light receiving means 802 is small. Accordingly, the light receiving means 802 outputs a high voltage signal (V) because the amount of light received increases when the concentration of abrasive grains mixed in the processing water is low, and the concentration of abrasive grains mixed in the processing water. When the voltage is high, the amount of received light is reduced, so a low voltage signal (V) is output. Based on the voltage signal (V) output from the light receiving means 802, the control means 9 determines whether or not the concentration of the abrasive grains mixed in the machining water is within an appropriate range. The determination procedure of the control means 9 will be described with reference to the flowchart shown in FIG.

  The control means 9 inputs a voltage signal (V) corresponding to the amount of light received from the light receiving means 802 in step S1. Then, the control means 9 proceeds to step S2, and checks whether or not the input voltage signal (V) is equal to or higher than the lower limit value (V1: for example, 3 volts) of the appropriate range. If the voltage signal (V) is greater than or equal to the lower limit value (V1) of the appropriate range in step S2, the control means 9 proceeds to step S3, where the voltage signal (V) is the upper limit value (V2: 4 volts, for example). ) Check if it is below. When the voltage signal (V) is not more than the upper limit value (V2) of the appropriate range in step S4, the control means 9 determines that the concentration of the abrasive grains mixed in the processing water is within the appropriate range, and Return to step S1. On the other hand, when the voltage signal (V) is lower than the lower limit (V1) of the appropriate range in step S2, the control means 9 determines that the concentration of the abrasive grains mixed in the machining water is too high, and step S4. Then, an error message indicating that the concentration of abrasive grains mixed in the processing water is too high is displayed on the display means 90 together with a voltage signal (V) corresponding to the amount of light received by the light receiving means 802. If the voltage signal (V) is higher than the upper limit (V2) of the appropriate range in step S3, the control means 9 determines that the concentration of the abrasive grains mixed in the machining water is too low, and step S4. Then, an error message indicating that the concentration of the abrasive grains mixed in the processing water is too low is displayed on the display means 90 together with the voltage signal (V) corresponding to the amount of light received by the light receiving means 802. Thus, by displaying the error message on the display means 90, the operator can confirm that the concentration of the abrasive grains mixed in the machining water is out of the proper range. That is, if the error message displayed on the display means 90 is an indication that the concentration of abrasive grains mixed in the processing water is too low, the operator replenishes the catch tank 60 with abrasive grains, for example. Further, when the error message displayed on the display means 90 is an indication that the concentration of the abrasive grains mixed in the processing water is too high, the operator replenishes the catch tank 60 with water, for example. Therefore, the concentration of the abrasive grains mixed in the processing water can be maintained in an appropriate range.

Next, the water jet processing which cut | disconnects the CSP board | substrate as a to-be-processed object with the water jet processing apparatus mentioned above is demonstrated.
First, a CSP substrate as a workpiece will be described with reference to FIGS.
In the CSP substrate 10 shown in FIGS. 5 and 6, three blocks 10a, 10b, and 10c are continuously formed on a metal plate 100. FIG. On the surface 100a of the three blocks 10a, 10b, and 10c constituting the CSP substrate 10, a plurality of first division planned lines 101 extending in a predetermined direction, respectively, and a direction orthogonal to the first division planned lines 101 Are formed in a lattice shape. A chip size package (CSP) 103 is arranged in each of a plurality of regions partitioned by the first planned division line 101 and the second planned division line 102, and this chip size package (CSP) 103 is divided into each block 10a, 10b and 10c are molded by synthetic resin portions 110a, 110b and 110c from the back side of the metal plate 100. The outer peripheral portion of the metal plate 100 constituting the CSP substrate 10 is formed so as to protrude outward from the three blocks 10a, 10b, 10c, and a plurality of positioning holes 104 ( In the illustrated embodiment, four) are provided. The CSP substrate 10 formed in this way is divided into chip size packages (CSPs) 103 cut along the first planned division line 101 and the second planned division line 102 and individually packaged.

  The CSP substrate 10 described above is held by the first workpiece holding jig 12a shown in FIG. 7 and the second workpiece holding jig 12b shown in FIG. 8, and the workpiece holding of the water jet machining apparatus is performed. It is held on the table 6. The first workpiece holding jig 12a shown in FIG. 7 and the second workpiece holding jig 12b shown in FIG. 8 are the same except for a first through groove and a second through groove which will be described later. Since it is a structure, the same code | symbol is attached | subjected and demonstrated to the same member. The first workpiece holding jig 12a shown in FIG. 7 and the second workpiece holding jig 12b shown in FIG. 8 are each composed of a lower clamping plate 13 and an upper clamping plate 14, and one side is on one side. The two hinges 15 and 15 are hinged to each other.

  The lower clamping plate 13 constituting the first workpiece holding jig 12a and the second workpiece holding jig 12b is made of a plate material formed in a rectangular shape by metal or synthetic resin, Is formed with a rectangular recess 130 into which the CSP board 10 is fitted. A plurality of positioning pins 131 into which a plurality of positioning holes 104 formed in the electrode plate 100 of the CSP substrate 10 are fitted are disposed on both sides in the longitudinal direction of the rectangular recess 130. Further, at the four corners of the lower clamping plate 13, for positioning that is fitted with four positioning pins 62 arranged on the first workpiece holding table 6a and the second workpiece holding table 6b. The four holes 132 are provided. Then, in the rectangular recess 130 of the lower holding plate 13 constituting the first workpiece holding jig 12a shown in FIG. 7, the first division line 101 of the CSP substrate 10 corresponding to the first scheduled dividing line 101 is provided. A through-groove 133a and a second through-groove 134a that alternately communicates with the adjacent first through-groove 133a at one end and the other end of the first through-groove 133a are formed. Further, in the rectangular recess 130 of the lower holding plate 13 constituting the second workpiece holding jig 12b shown in FIG. 8, the first corresponding to the second scheduled division line 102 of the CSP substrate 10 is provided. A through-groove 133b and a second through-groove 134b that alternately communicates with the adjacent first through-groove 133b at one end and the other end of the first through-groove 133b are formed.

  An opening 141 is provided in each of the upper holding plates 14 constituting the first workpiece holding jig 12a and the second workpiece holding jig 12b. The opening 141 is similar in shape to the CSP substrate 10 and is formed to have a slightly smaller size than the CSP substrate 10.

  In order to cut the CSP substrate 10 along the first scheduled division line 101 and the second scheduled division line 102, first, the CSP substrate 10 is mounted on the lower clamping plate 13 of the first workpiece holding jig 11a. Put. At this time, the CSP substrate 10 is fitted into the rectangular recess 130 and the plurality of positioning holes 104 formed in the electrode plate 100 are fitted into the plurality of positioning pins 131 provided in the lower holding plate 13. . Then, the upper clamping plate 14 is overlapped to engage the engagement piece 16 with the engagement recess 133. When the CSP substrate 10 is set in the first workpiece holding jig 12a in this way, the first workpiece holding jig 12a on which the CSP substrate 10 is set is inserted into the workpiece loading / unloading opening 1d. Through the workpiece holding table 6. At this time, the four pin holes 132 provided in the lower holding plate 13 of the first workpiece holding jig 12 a are fitted with the four positioning pins 62 provided in the workpiece holding table 6. Thus, the first workpiece holding jig 12a on which the CSP substrate 10 is set is held at a predetermined position of the workpiece holding table 6.

  If the first workpiece holding jig 12a on which the CSP substrate 10 is set is held at a predetermined position of the workpiece holding table 6 in the water jet machining apparatus, the control means 9 includes the first moving means 30 and The CSP substrate held on the workpiece holding table 6 by operating the third moving means 50 and moving the first movable base 3 and the third movable base 5 in the directions indicated by the arrows X and Y. 10 is moved to a machining area below the nozzle 72, and a predetermined machining start position is positioned immediately below the nozzle 72. Then, the control unit 9 operates the second moving unit 40 to move the second movable base 4 in the direction indicated by the arrow Z, and moves the nozzle 72 upward from the surface of the CSP substrate 10 at a predetermined interval (for example, 50 μm). ).

  Next, the high-pressure water feed pump 732 constituting the high-pressure water supply means 73 of the processed water injection means 7 is operated and the first high-pressure water on-off valve 79a is energized (ON), so that the first first The injection process is performed to inject processing water mixed with abrasive grains from the nozzle 72, and the third moving unit 50 and the first moving unit 30 are operated to operate the third movable base 5 and the first moving unit 5. By sequentially moving the movable base 3 in the directions indicated by the arrows Y and X, the workpiece holding table 6, that is, the CSP substrate 10 is moved to the nozzle 72 with respect to the first workpiece holding jig 12 a as a lower clamping plate. 13 is moved along the first through-groove 133a and the second through-groove 134a. As a result, the CSP substrate 10 is formed on the lower clamping plate 13 of the first workpiece holding jig 12a along all of the first scheduled dividing line 101 and a part of the second scheduled dividing line 102 (see FIG. The first through groove 133a and the second through groove 134a) are cut (first cutting step). At the time of cutting, the high-pressure processing water penetrates the CSP substrate 10, but the high-pressure processing water after cutting passes through the first through-groove 133 a and the second through-groove 134 a formed in the lower holding plate 13. As a result, the momentum is moderated by the buffer water contained in the catch tank 60.

  When the first cutting step is performed, the control means 9 performs the first injection step and the first working water replenishment step based on the detection signals from the abrasive grain amount detection means 81a and 81b. The second injection step and the second process water replenishment step are alternately performed.

  If the 1st cutting process mentioned above was implemented, the 1st workpiece holding jig 12a which clamps the CSP board | substrate 10 in which the 1st cutting process was implemented will be removed from the workpiece holding table 6. FIG. Then, the CSP substrate 10 sandwiched by the first workpiece holding jig 12a is set on the second workpiece holding jig 12b. The CSP substrate 10 is set in the same manner as the setting to the first workpiece holding jig 12a.

  If the CSP substrate 10 is set on the second workpiece holding jig 12b, the second workpiece holding jig 12b on which the CSP substrate 10 is set is placed on the workpiece holding table 6. Similar to the first workpiece holding jig 12a, the workpiece holding table 6 is held at a predetermined position. Next, the first moving means 30 and the third moving means 50 are operated to move the first movable base 3 and the third movable base 5 in the directions indicated by arrows X and Y, and The CSP substrate 10 held on the workpiece holding table 6 is moved to a machining area below the nozzle 72, and a predetermined machining start position is positioned, for example, directly below the nozzle 72. Then, the second moving means 40 is operated to move the second movable base 4 in the direction indicated by the arrow Z, and the nozzle 72 is placed above the surface of the CSP substrate 10 at a predetermined interval (for example, 50 μm). Position in place.

  Next, the first injection step is performed to inject the processing water mixed with abrasive grains from the nozzle 72, and the third moving unit 50 and the first moving unit 30 are operated to operate the third movable unit. By sequentially moving the base 5 and the first movable base 3 in the directions indicated by the arrows Y and X, the workpiece holding table 6, that is, the CSP substrate 10 is held with respect to the nozzle 72 by the second workpiece. The jig 12b is moved along the first through-groove 133b and the second through-groove 134b formed in the lower clamping plate 13 of the jig 12b. As a result, the CSP substrate 10 is formed on the lower clamping plate 13 of the second workpiece holding jig 12b along all of the second scheduled dividing line 102 and a part of the first scheduled dividing line 101 (see FIG. The first through groove 133b and the second through groove 134b) are cut (second cutting step). At the time of cutting, the high-pressure processing water penetrates the CSP substrate 10, but the high-pressure processing water after cutting passes through the first through-groove 133 b and the second through-groove 134 b formed in the lower clamping plate 13. As a result, the momentum is moderated by the buffer water contained in the catch tank 60.

  Even when the second cutting step is being performed, the control means 9 is based on the detection signals from the abrasive grain amount detecting means 81a and 81b, and the first injection step and the first working water replenishment are performed. The process, the second injection process, and the second process water replenishment process are performed alternately.

  If the 2nd cutting process mentioned above was implemented, the 2nd workpiece holding jig | tool 12b which clamps the CSP board | substrate 10 in which the 2nd cutting process was implemented will be removed from the workpiece holding table 6. FIG. By performing the first cutting step and the second cutting step as described above, the CSP substrate 10 is cut along the first division planned line 101 and the second division planned line 102, and the individual Divided into chip size packages (CSP).

  While carrying out the first cutting step and the second cutting step, the concentration of abrasive grains mixed in the processing water sprayed from the nozzle 72 changes. If the concentration of abrasive grains mixed in the processing water changes and the concentration deviates from an appropriate range, there is a problem that the processing accuracy is not stable as described above. Therefore, the machining water jetting means 7 of the laser machining apparatus in the illustrated embodiment operates the abrasive concentration detecting means 80 as described above, and machining that flows through the common machining water delivery pipe 76c connected to the nozzle 72. The concentration of abrasive grains mixed in water is detected. When the operator confirms the concentration of the abrasive grains mixed in the processing water detected by the abrasive concentration detection means 80, and the concentration of the abrasive grains mixed in the processing water is lower than the lower limit value of the appropriate range In the case where the abrasive grains are replenished and the concentration of the abrasive grains is higher than the upper limit of the appropriate range, the concentration of the abrasive grains mixed in the processing water can be maintained in the proper range by replenishing water.

1 is a perspective view of a water jet machining apparatus configured according to the present invention. The block diagram of a structure of the process water injection means which comprises the water jet processing apparatus shown in FIG. Explanatory drawing which fractures | ruptures and shows the principal part of the abrasive-grain density | concentration detection means which comprises the process water injection means shown in FIG. The flowchart which shows the abrasive grain concentration procedure of the control means which comprises the abrasive grain density | concentration detection means shown in FIG. The perspective view of the CSP board | substrate as a to-be-processed object. Sectional drawing of the CSP board | substrate shown in FIG. The perspective view of the 1st workpiece holding jig | tool for hold | maintaining the CSP board | substrate as a workpiece and mounting on the workpiece holding table of a water jet processing apparatus. The perspective view of the 2nd workpiece holding jig for hold | maintaining the CSP board | substrate as a workpiece and mounting on the workpiece holding table of a water jet processing apparatus.

Explanation of symbols

2: stationary base 3: first movable base 30: first moving means 4: second possible base 40: second moving means 5: third movable base 50: third moving means 6: Workpiece holding table 60: Catch tank 7: Processing water injection means 71a: First high pressure tank 71b: Second high pressure tank 711a, 711b: Processing water delivery pipes 712a, 712b: High pressure water supply pipes 713a, 713b : Processing water discharge pipes 714a, 714b: Processing water suction pipes 715a, 715b: Processing water supply pipes 72: Nozzle 73: High pressure water supply means 74: Processing water replenishment means 741: Suction pump 743: Abrasive filter 745a, 745b: Electromagnetic On-off valves 746a, 746b: electromagnetic on-off valves 77a: first processing water on-off valves 77b: second processing water on-off valves 78a: first processing water merging means 78b: second processing water merging means 79a: first High pressure water Valve closing 79b: Second high pressure water on / off valve 80: Abrasive grain concentration detecting means 801: Light emitting means 802: Light receiving means 81a: First abrasive grain amount detecting means 81b: Second abrasive grain amount detecting means 9: Control means 10: CSP substrate (workpiece)
12a: first workpiece holding jig 12b: second workpiece holding jig

Claims (4)

A workpiece holding means for holding the workpiece, and a processing water injection means for injecting the processing water in which abrasive grains are mixed into the workpiece held by the workpiece holding means. In a water jet machining apparatus comprising: a processing water sending means for sending processing water mixed with abrasive grains; and a nozzle for jetting the processing water sent from the processing water sending means.
Comprising abrasive concentration detecting means for detecting the concentration of abrasive particles mixed in the processing water in the processing water delivery pipe connecting the processing water delivery means and the nozzle;
A water jet machining apparatus characterized by that.   The abrasive grain concentration detecting means is based on a light emitting means for emitting detection light into the processed water delivery pipe, a light receiving means disposed opposite to the light emitting means, and an amount of light received by the light receiving means. The water jet machining apparatus according to claim 1, comprising control means for obtaining a concentration of abrasive grains mixed in the machining water.   The water jet machining apparatus according to claim 2, wherein the control means outputs an error message to the display means when the concentration of the abrasive grains is not within an allowable range.   A pair of opening windows provided opposite to each other are formed in the processed water delivery pipe, and sapphire is mounted on each of the pair of opening windows, and the light emitting means is disposed on one of the pair of opening windows. The water jet processing apparatus according to claim 1, wherein the light receiving means is disposed on the other of the pair of opening windows.

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