JP2004167617A - Grinding head structure equipped with cup wheel type whetstone - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grinding head structure of simple configuration capable of hindering dust from stagnating between the print wiring surface of a semiconductor board and a sticky film for protecting the print wiring surface. <P>SOLUTION: The grinding head 50 is equipped at its oversurface with a central recess 60 and with grooves 61 to serve as a flow passage arranged radially toward the outside from the central recess, and a water supply guide 59 having a plurality of slopes 62 and 63 with the gradient becoming lesser gradually toward the outside is fixed to the lower part of a hollow shaft 57 through a ring-shaped flange 56 fixed to the lower periphery of the hollow shaft 57, and a metal base 53 of a cup wheel type whetstone is fixed to the ring-shaped flange through a ring projection 55, and a cup-shaped lid is formed from the bottom wall, the ring projection, and the flange so as to prevent the grinding liquid from leaking out from the over-part when the hollow shaft rotates. The grinding liquid supplied to the inside of the hollow shaft is introduced to inside the peripheral wall via the surface of the water supply guide and is fed by pressure to the surface to be processed where any work and a whetstone piece 54 are in slide contact by the centrifugal force generated by rotation of the water supply guide 59. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a grinding head structure including a semiconductor substrate such as a silicon wafer, a germanium wafer, an aluminum wafer, and a glass substrate, and a cup wheel type grindstone used for surface grinding (including polishing) a metal plate.
[Prior art]
[0002]
As the cup wheel type grindstone 5, an annular peripheral wall 5a shown in FIG. 5 and a fan-shaped grindstone piece 5d are formed on the lower surface thereof in such a manner that a slit 5f through which a grinding fluid flows is formed between adjacent grindstone pieces with an adhesive. A cup wheel type grindstone with a grinding stone piece height of 3 to 5 mm (see Japanese Utility Model Unexamined Publication Nos. 61-144959, 61-144961, 61-144962, and JP-A-62-181875) is used. It had been.
In this cup wheel type grindstone, the use efficiency of the grinding fluid is poor because the grinding fluid is supplied to the grinding surface from outside the grindstone.
[0003]
In order to increase the utilization efficiency of the grinding fluid, a center system in which the grinding fluid is supplied to the grinding surface from the inside of the cup wheel type grindstone is preferable.
The following are known as center-type cup wheel-type grindstones.
{Circle around (1)} A mounting hole for the grinding fluid supply hollow shaft is opened at the center of the base of the grinding wheel main body, and a fluid path extending radially outward from the center is provided. A cup wheel-type grindstone in which a diamond grindstone piece is fixed between the opening of each of the liquid receiving passages of the peripheral wall at the contact surface with the work (see JP-A-60-232877).
[0004]
(2) As shown in FIG. 4, a cup-shaped base metal 2 having an annular peripheral wall portion 18, a grindstone piece 6 provided on the lower end surface 4, and a liquid receiving recess formed on an upper end surface of the base metal 12. And a liquid supply hole 16 having one end opened on the inner bottom surface of the liquid receiving recess and the other end opened at a position on the inner surface side of the peripheral wall portion 2b on the lower surface of the base metal, and the inner peripheral surface 8 of the peripheral wall portion is provided. Is a cup wheel-type grindstone 1 for a surface grinding device having an inclined surface extending outward from the upper side to the lower side (Japanese Patent Laid-Open Nos. 5-69339, 6-278036, 9-38866, and 2000) -94342, Japanese Patent No. 2503158, Japanese Patent No. 2500285). In the cup wheel type grindstones disclosed in these publications, the grinding fluid is supplied to the recess 14 on the upper surface of the base metal using a supply nozzle, and the grinding wheel piece 6 passes through the inclined grinding fluid supply hole 16. And the grinding fluid is guided to the work contact surface.
[0005]
(3) As shown in FIG. 3, the annular peripheral wall 18 and a bottom wall 20 provided at one end thereof have a cup-like shape, and a grinding fluid introduction hole 28 penetrating the bottom wall. While the grinding fluid is supplied to the inside of the peripheral wall through the grinding fluid introduction hole, it is rotated around the axis and the grinding wheel piece 30 provided on the lower surface of the peripheral wall is brought into sliding contact with the work plane 14 so that the work surface is formed. A cup-shaped grindstone that grinds the grinding fluid, comprising a main body part 34 that covers an inner surface opening of the bottom wall 20 of the grinding fluid introduction hole 28 at a predetermined distance from the inner surface of the bottom wall, and is fixed to the bottom wall, A cup-type grindstone provided with a rotating impeller 16 having a plurality of blades 42 erected at predetermined intervals in a circumferential direction on one surface of a bottom wall side of the main body portion in a direction opposite to the rotation direction toward an outer peripheral side. (JP-A-9-38666).
The impeller 16 acts like a pump to pump the grinding fluid to the sliding surface between the grinding wheel and the work.
[0006]
In the cup type grinding wheel of (1), since the opening end of the liquid receiving passage is provided between the grinding wheel pieces, a large amount of the grinding fluid escapes to the outside of the grinding wheel due to centrifugal force, and the utilization rate of the grinding fluid is low.
[0007]
In the cup type grinding wheel of the above item (2), the mounting position of the nozzle for supplying the grinding liquid to the liquid receiving concave portion 14 is restricted, and the diameter of the substrate as the work is increased to 200 mm, 300 mm, and 400 mm. As the thickness becomes as thin as 20 to 100 μm, the chance of grinding dust entering between the printed circuit surface of the work and the adhesive film protecting the same increases, which is not preferable.
[0008]
In the cup-type grindstone provided with the rotary impeller of the above (3), a large amount of grinding fluid is supplied to the grindstone pieces, and grinding chips and abrasive grains enter between the printed circuit surface of the work and the adhesive film for protecting the same. This has the advantage of reducing opportunities, but the mounting position of the plurality of nozzles 46 for supplying the grinding fluid to the grinding fluid introduction hole 28 is limited, and the nozzle mounting structure is complicated.
[0009]
[Problems to be solved by the invention]
The present invention simplifies the supply of the grinding fluid to the grinding head structure by fixing the grindstone to a rotating shaft having a grinding fluid introducing section, and providing a water supply guide below the rotating shaft to remove grinding dust and abrasive grains. To provide a grinding head structure provided with a cup wheel-type grindstone that rarely penetrates between a printed circuit surface of a workpiece and an adhesive film protecting the same.
[0010]
[Means for Solving the Problems]
In the first aspect of the present invention, a cup-shaped base is formed by an annular peripheral wall in which grinding stone pieces are annularly implanted at predetermined intervals in a lower part and a bottom wall provided at one end thereof, and a grinding fluid is provided inside the peripheral wall. The cup wheel-type grindstone used to grind the work surface by being rotated about the axis while being supplied and being brought into sliding contact with the work surface by the grindstone piece implanted under the peripheral wall being hollow. Grinding head structure bearing on the shaft,
A water supply guide having a central concave portion on the upper surface, providing a channel groove radially outward from the central concave portion, and having a plurality of inclined portions whose inclination gradually decreases outward is provided around the lower part of the hollow shaft. It is fixed to the lower part of the hollow shaft through a fixed annular flange, and the base of the cup wheel-type grindstone is fixed to the annular flange through an annular projection, and a bowl is formed by the bottom wall, the annular projection and the annular flange. A grinding lid is formed to prevent the grinding fluid from leaking out from above during rotation of the hollow shaft. The grinding fluid supplied to the inside of the hollow shaft is provided with a central concave portion of the water supply guide, a groove for a flow path, and a plurality of inclined portions. The work is introduced to the inside of the peripheral wall via the portion and further supplied to the processing surface where the work and the grindstone piece are in sliding contact with each other by centrifugal force generated by rotation of the water supply guide around the hollow shaft center. The grinding head structure It is intended to provide.
[0011]
Since the grinding fluid is supplied to the hollow shaft, the structure of the grinding head portion is cleaner than that of the conventional grinding head structures (2) and (3) provided with nozzles, and the grinding operation is easy. In addition, when the grinding fluid supplied to the central recess of the water supply guide enters the flow channel groove, the flow force increases and centrifugal force is also applied, so the pumping force is high, and the grinding chips and abrasive grains are quickly removed between the grinding wheel pieces. And escape from the grindstone, so that they rarely enter the space between the printed circuit surface of the work and the adhesive film protecting it. In addition, by making the inclined portion of the outer peripheral portion of the water supply guide multistage, it is easy to supply the grinding fluid to the sliding contact surface between the grindstone piece and the work surface.
[0012]
According to a second aspect of the present invention, in the grinding head structure, the plurality of inclined portions of the water supply guide have two steps, and the inclined portion a on the center side has an angle of 30 to 60 degrees with respect to the horizontal plane, The inclined portion b has an angle of 5 to 20 degrees with respect to the horizontal plane, and the lower surface of the annular flange opposed to the outer inclined portion b has a space formed by the inclined portion b and the lower surface of the annular flange. It is characterized by being inclined outwardly so as to become gradually narrower.
[0013]
Since the space formed by the two-step inclined surface of the water supply guide and the lower inclined surface of the annular flange gradually narrows, the pressure of the grinding fluid to be pumped increases, and grinding chips and abrasive grains can be quickly removed from the slit between the grinding wheel pieces. Escape outside the whetstone.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view showing a grinding head structure according to the present invention, in which dimensions are described in an actual example of grinding a substrate having a diameter of 300 mm. FIG. 2 is a plan view of a water supply guide used in the grinding head structure of the present invention. The cross section of the water supply guide 59 shown in FIG. 1 is a view seen from the II cutting line in FIG.
[0015]
As shown in FIGS. 1 and 2, the grinding head structure 50 of the present invention has a cup-like shape including an annular peripheral wall 51 in which grinding stone pieces 54 are annularly implanted at predetermined intervals in an annular shape and a bottom wall 52 provided at one end thereof. The base metal 53 is used, and these form a cup wheel type grindstone.
The grinding fluid is guided to the hollow portion 58 of the hollow shaft 57 using a pump and a water supply pipe (not shown), and is passed through a flow path space 64 formed by the upper surface of the water supply guide 59 and the lower surface of the annular flange 56. And the grinding fluid is supplied to the surface of the work surface in sliding contact with the grinding wheel piece 54.
[0016]
The base 53 of the cup wheel-type grindstone is fixed to the annular projection 55 by a bolt 67, and the annular projection 55 is fixed to the annular flange 56 by a bolt 68, and the annular flange 56 is fixed to a lower portion of the hollow shaft 58. . 70 is an oil sealing. A bowl-shaped lid is formed by the bottom wall, the annular projection, and the annular flange to prevent the grinding fluid from leaking from above to the outside during rotation of the hollow shaft.
[0017]
The water supply guide 59 is fixed to the lower surface of the annular flange 56 by a bolt 69 such that the axis 59a coincides with the axis 57a of the hollow shaft. This water supply guide has a central concave portion 60 on the upper surface, a flow channel groove 61 is provided radially outward from the central concave portion, and a two-step inclined portion 62, 63 whose inclination gradually decreases outward. Have. The grinding fluid supplied to the inside of the hollow shaft 58 is guided to the central concave portion 60, and is introduced into the inner space 66 of the peripheral wall 51 via the flow channel groove 61 and the two sets of inclined portions 62 and 63. A structure is employed in which the grinding fluid is supplied to the processing surface where the work and the grindstone piece are in sliding contact by centrifugal force due to rotation of the water supply guide about the hollow shaft center 59a.
[0018]
The plurality of inclined portions of the water supply guide are in two stages, the central inclined portion a62 has an angle α of 30 to 60 degrees with respect to the horizontal plane, and the outer inclined portion b63 has an angle β of 5 to 20 with respect to the horizontal plane. The lower surface of the annular flange opposed to the outer inclined portion b is inclined outward so that the space formed by the inclined portion b and the lower surface of the annular flange gradually narrows. I have. As for the inclination angle of the lower surface of the annular flange, the inner angle γ is 35 to 60 degrees, and the outer angle θ is 10 to 20 degrees. In the water supply guide 59 of the 300 mm base grinding head structure shown in FIG. 1, the angle α is 45 degrees, the angle β is 10 degrees, the angle γ is 45 degrees, and the angle θ is 15 degrees.
It is preferable in terms of design that the length of the inclined surface a of the center side is shorter than that of the outer inclined portion b.
[0019]
The inclined portion of the water supply guide may have a plurality of stages and a structure in which the inclination angle is gradually reduced, and may be two stages or three to five stages as described above.
[0020]
Aluminum is used as a material of the base metal 53, and glass fiber reinforced resin is used as a material of the water supply guide 59. The grindstone pieces 54 are formed by molding abrasive grains such as diamond abrasive grains and CBN abrasive grains with an adhesive such as phenol resin or epoxy resin, and are provided on the lower surface of the peripheral wall at equal intervals in a ring shape. In the cup wheel type grindstone, it is preferable that the height of the slit between the grindstone pieces is 3 to 10 mm, the width of the grindstone piece is 2 to 7 mm, and the length of the grindstone piece divided by the slit is 10 to 50 mm. The inner diameter of the grinding fluid introduction hollow portion 58 is preferably about 25 mm.
[0021]
【Example】
Example 1
A precision surface grinding device SVG502MK-II (trade name) manufactured by Okamoto Machine Tool Works, Ltd. was used as a grinding device, and a grinding head structure equipped with a cup wheel type diamond grinding wheel shown in FIG. 1 was fixed to a hollow spindle of the device. .
On a substrate holder, a semiconductor substrate having a diameter of 200 mm with an adhesive protection film adhered to a printed wiring surface portion is held such that the silicon substrate surface faces upward (the adhesive film faces downward), and the substrate holder is held at 100 min ^-1 . The hollow spindle was rotated at 300 min ^-1 and the grinding head structure was lowered while supplying a grinding liquid to the hollow portion of the hollow spindle, and a grinding wheel piece was slid on the silicon substrate surface of the semiconductor substrate to perform grinding for 2 minutes.
After the grinding of the substrate, the ground surface of the substrate was brush-scrub-cleaned and spin-dried. After observing whether or not dust (abrasive particles or grinding dust) existed between the adhesive film and the printed wiring of the semiconductor substrate, No dust was found.
[0022]
【The invention's effect】
The grinding head structure of the present invention has a structure in which a grinding fluid is introduced from a hollow shaft and supplied to the grinding piece of the cup-shaped grindstone and the sliding surface of the work surface via a water supply guide. The structure around the cup-shaped grindstone is simple, and a large amount of grinding fluid is pumped to the grinding surface of the cup-shaped grindstone and the sliding surface of the work surface. Will not accumulate.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a grinding head structure of the present invention.
FIG. 2 is a plan view of a water supply guide used in the grinding head structure of the present invention.
FIG. 3 is a partial sectional view of a grinding head provided with a cup wheel type grindstone. (Known)
FIG. 4 is a cross-sectional view of a cup wheel-type grindstone. (Known)
FIG. 5 is a perspective view of a cup wheel-type grindstone. (Known)
[Explanation of symbols]
Reference Signs List 50 grinding head structure 51 peripheral wall 52 bottom wall 53 base metal 54 grindstone piece 55 annular protrusion 56 annular flange 57 hollow shaft 59 water supply guide 60 central concave portion 61 flow channel groove 62 inclined portion a
63 Inclined part b
64 channel 65 outlet 66 space

Claims (2)

An annular peripheral wall in which grinding stone pieces are annularly implanted at predetermined intervals in the lower part and a bottom wall provided at one end form a cup-shaped base metal, and the inner peripheral wall is rotated around the axis while the grinding fluid is supplied. A grinding wheel structure in which a cup wheel type grindstone used to grind the work surface is slidably brought into contact with the surface of the work by grinding a piece of grindstone implanted at a lower portion of the peripheral wall, and is supported on a hollow shaft. So,
A water supply guide having a central concave portion on the upper surface, providing a channel groove radially outward from the central concave portion, and having a plurality of inclined portions whose inclination gradually decreases outward is provided around the lower part of the hollow shaft. It is fixed to the lower part of the hollow shaft through a fixed annular flange, and the base of the cup wheel-type grindstone is fixed to the annular flange through an annular projection, and a bowl is formed by the bottom wall, the annular projection and the annular flange. A grinding lid is formed to prevent the grinding fluid from leaking out from above during rotation of the hollow shaft. The grinding fluid supplied to the inside of the hollow shaft is provided with a central concave portion of the water supply guide, a groove for a flow path, and a plurality of inclined portions. The work is introduced to the inside of the peripheral wall via the portion and further supplied to the processing surface where the work and the grindstone piece are in sliding contact with each other by centrifugal force generated by rotation of the water supply guide around the hollow shaft center. The grinding head structure . The plurality of inclined portions of the water supply guide have two steps, the central inclined portion a has an angle of 30 to 60 degrees with respect to the horizontal plane, and the outer inclined portion b has an angle of 5 to 20 degrees with respect to the horizontal surface. The lower surface of the annular flange opposed to the outer inclined portion b is inclined so that the space formed by the inclined portion b and the lower surface of the annular flange is gradually narrowed outward. The grinding head structure according to claim 1, wherein:

Images