TW201544244A - Grinding device and grinding method for rectangular substrate - Google Patents

Abstract

This invention provides a grinding device and a grinding method for rectangular substrate capable of inhibiting large scale of grinding wheel. The solution is a grinding device for grinding the front or back surface of a rectangular substrate, characterized by comprising a working chuck, a grinding means, a grinding feed means, a Y-axis movement means and an X-axis movement means. The working chuck has a holding surface for sucking and holding the rectangular substrate. The grinding means rotationally supports the grinding wheel for grinding the rectangular substrate held on the working chuck. The grinding feed means feeds the grinding means in the vertical direction relative to the holding surface of the working chuck. The Y-axis movement means moves the working chuck relative to the grinding means in the Y-axis between the handling area for loading/unloading the rectangular substrate and the grinding area for grinding the rectangular substrate. The X-axis movement means moves the working chuck relative to the grinding means in the X-axis direction perpendicular to the Y-axis direction. The grinding wheel comprises a grinding wheel base and a grindstone annularly arranged at the outer circumference of the lower surface of the grinding wheel base, and the outer diameter of the annularly arranged grindstone is set as smaller than the shorter edge of the rectangular substrate.

Description

Grinding device and grinding method of rectangular substrate Field of invention

The present invention relates to a grinding apparatus suitable for grinding a rectangular substrate such as a large package substrate, and a grinding method of a rectangular substrate using the same.

Background of the invention

In the process of the semiconductor device, a plurality of semiconductor wafers on which circuits such as LSIs are formed are mounted on a lead frame or a printed circuit board, and after the electrodes of the semiconductor wafer are bonded to the electrodes of the substrate, the front surface is sealed with a resin. Or the back surface to form a package substrate such as a CSP (Chip Size Package) substrate or a BGA (Ball Grid Array) substrate.

Then, the package substrate is diced by using a cutter or the like to form a single piece of semiconductor element to be sealed by a resin (see, for example, Japanese Laid-Open Patent Publication No. 2009-253058). The semiconductor element manufactured in this manner is widely used in various electronic devices such as mobile phones and personal computers.

With the miniaturization and thinning of electronic devices in recent years, semiconductor devices are also expected to be miniaturized and thinned. In the process of semiconductor devices, there is a resin sealing surface grinding of a package substrate on which a semiconductor wafer is sealed by a resin. The requirement of thinning and thinning, or the requirement to grind and thin the back surface of a semiconductor wafer mounted on a printed circuit board.

Among these grindings, a grinding device called a grinder disclosed in, for example, Japanese Laid-Open Patent Publication No. 2008-272866 is widely used. The grinding device includes a working chuck for sucking a workpiece to be held such as a package substrate, and a grinding wheel having a grinding vermicite disposed to face the workpiece held by the working chuck, and grinding the vermiculite Grinding is performed by slipping in a state in which it is abutted against the object to be ground.

In order to form a uniform thickness of the sealing resin coated on the back surface of the package substrate such as a CSP substrate, the sealing resin can be ground by a grinding device (see, for example, Japanese Laid-Open Patent Publication No. 2011-192781).

Prior technical literature Patent literature

Patent Document 1: Japanese Patent Laid-Open Publication No. 2009-253058

Patent Document 2: Japanese Patent Laid-Open Publication No. 2008-272866

Patent Document 3: Japanese Patent Laid-Open Publication No. 2011-192781

Summary of invention

However, in recent years, a package substrate such as a CSP substrate has been increased in size to, for example, 500 mm × 700 mm. With this, the grinding wheel of the grinding device is also increased in size, and the replacement of the grinding wheel becomes difficult. Further, with the increase in the size of the grinding wheel, there is a problem that the grinding device has to be enlarged.

The present invention has been made in view of such problems, and its object is It is to provide a grinding device capable of suppressing an increase in size of a grinding wheel and a grinding method of a rectangular substrate.

According to the invention of claim 1, there is provided a grinding apparatus for grinding a front side or a back side of a rectangular substrate. The grinding apparatus is characterized by comprising: a working clamping table having a holding surface for attracting and holding a rectangular substrate; and a grinding means for supporting a grinding wheel for grinding a rectangular substrate held on the working clamping table to be rotatable a grinding feed means for grinding the grinding means in a vertical direction with respect to the holding surface of the working table; the Y-axis moving means, the working clamping table and the grinding means are in the Y-axis direction Relatively moving between the loading and unloading area of the loading and unloading rectangular substrate and the grinding area of the ground rectangular substrate; and the X-axis moving means to make the working clamping table and the grinding means are opposite to each other in the X-axis direction orthogonal to the Y-axis direction Move on the ground.

The grinding wheel includes a grinding wheel base, and a grinding vermicite disposed in an annular shape on an outer peripheral surface of the lower surface of the grinding wheel base, and setting an outer diameter of the grinding meteorite arranged in a ring shape to be The short side of the rectangular substrate is also small.

Preferably, a clamping means for holding a rectangular substrate held on the working table is disposed on the working table. Preferably, the grinding device includes a cutting device that mounts a cutting blade for cutting a rectangular substrate held on the working table to be rotatable.

According to the invention of claim 4, there is provided a method of grinding a rectangular substrate using a grinding device according to the third aspect to grind a rectangular substrate, The method for grinding a rectangular substrate is characterized in that it comprises a cutting step of forming a cutting groove having a depth not to be grounded by a cutting blade held by the cutting means to relax a rectangular substrate Internal stress; and a grinding step, after the cutting step is performed, the grinding is held on the rectangular substrate of the working clamping table.

Preferably, when the cutting blade of the cutting means forms a cutting groove having a depth not to reach the grinding depth, the rectangular substrate is sandwiched by the holding means, and the holding means is released after the cutting groove has been formed.

According to the grinding apparatus of the present invention, since the outer diameter of the grinding vermiculite arranged in a ring shape is set to be smaller than the short side of the rectangular substrate, the enlargement of the grinding wheel can be suppressed and the replacement of the grinding wheel can be changed. It's easy. Moreover, since the grinding wheel can be made small, it is possible to suppress an increase in size of the grinding device.

Further, since the clamping means is provided, even if the curved rectangular substrate can be held on the working table, and the cutting means is provided, the internal stress of the rectangular substrate can be relaxed and the bending can be corrected, even if the clamping means is released. The rectangular substrate is held by the attractive force of the working clamp.

2‧‧‧grinding device

4‧‧‧Base

6‧‧‧ pillar

8, 18‧‧‧ rails

10‧‧‧Z-axis moving block

11‧‧‧Rectangular package substrate

11a‧‧‧The front side of the package substrate

11b‧‧‧The back of the package substrate

11c‧‧‧ grinding area

12, 22‧‧‧ ball screw

13‧‧‧Substrate

14, 24‧‧ ‧ pulse motor

15‧‧‧Split line

16‧‧‧Z-axis moving mechanism (grinding unit feed mechanism)

17‧‧‧ Wafer Formation Department

19‧‧‧Semiconductor wafer

20‧‧‧Support block

21‧‧‧Resin (sealing resin)

23‧‧‧Cutting trench

26‧‧‧X-axis moving mechanism

28‧‧‧ Grinding unit (grinding means)

30, 50‧‧‧ spindle housing

32, 52‧‧‧ spindle

34‧‧‧Motor

36‧‧·wheel seat

38‧‧‧ grinding wheel

40‧‧‧ wheel base

42‧‧‧ grinding grinding stone

44‧‧‧Cutting unit (cutting means)

46‧‧‧Fixed components

48‧‧‧moving components

54‧‧‧Cutter

56‧‧‧Working table mechanism

58‧‧‧Working table

58a‧‧‧ Keep face

60‧‧‧Waterproof cover

62, 64‧‧‧ telescopic bladder

66‧‧‧Operator panel

68‧‧‧Clamps (clamping means)

A‧‧‧ wafer loading and unloading position

B‧‧‧ grinding position

a, b, Y1, Y2‧‧‧ arrows

X, Y, Z‧‧ Direction

Fig. 1 is a perspective view of a grinding apparatus according to an embodiment of the present invention.

2(A) is a perspective view showing a surface side of a package substrate, FIG. 2(B) is a perspective view showing a back side of the package substrate, and FIG. 2(C) is a partially enlarged side view showing the package substrate.

3(A) to (C) are schematic plan views showing the cutting step.

Fig. 4 (A) is a schematic perspective view of a grinding method, and Fig. 4 (B) is a schematic plan view showing a grinding method of the first embodiment.

Fig. 5 (A) is a schematic plan view showing a grinding method according to a second embodiment, Fig. 5 (B) is a schematic plan view showing a grinding method according to a third embodiment, and Fig. 5 (C) is a view showing a fourth embodiment. A schematic plan view of the grinding method.

Form for implementing the invention

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Referring to Fig. 1, there is shown an external perspective view of a grinding apparatus 2 according to an embodiment of the present invention. 4 is a base of the grinding device 2, and a pillar 6 is provided upright at the rear of the base 4.

A pair of guide rails 8 extending in the up and down direction are fixed to the pillars 6. Guided by the pair of guide rails 8, the Z-axis moving block 10 is disposed to be movable in the Z-axis direction (up-and-down direction) by the Z-axis moving mechanism 16 constituted by the ball screw 12 and the pulse motor 14.

A pair of guide rails 18 extending in the X-axis direction are fixed to the Z-axis moving block 10. The pair of guide rails 18 are guided to transmit the support block 20 so as to be movable in the X-axis direction through the X-axis moving mechanism 26 constituted by the ball screw 22 and the pulse motor 24.

A grinding unit (grinding means) 28 is supported on the support block 20. The grinding unit 28 includes a spindle housing 30, a spindle 32 rotatably housed in the spindle housing 30, a motor 34 that rotationally drives the spindle 32, a wheel mount 36 that is fixed to the front end of the spindle 32, and is detachably mounted to Grinding wheel 38 on wheel base 36.

As shown in FIG. 4(A), the grinding wheel 38 is an annular wheel base 40. It is composed of a plurality of grinding vermiculite 42 adhered to the outer peripheral portion of the lower surface of the wheel base 40. The outer diameter of the grinding vermicite 42 disposed in a ring shape is set to be smaller than the short side of the package substrate 11 shown in FIG.

A cutting unit (cutting means) 44 is mounted on the support block 20. The fixing member 46 of the cutting unit 44 is fixed to the support block 20, and the moving member 48 is mounted to be movable in the Z-axis direction with respect to the fixed member 46 through a cylinder or the like.

The spindle housing 50 is fixed to the moving member 48, and the spindle 52 is rotatably accommodated in the spindle housing 50. The spindle 52 is rotationally driven by a motor (not shown) housed in the spindle housing 50. A cutter 54 is attached to the front end of the main shaft 52.

A working chuck mechanism 56 is disposed on the base 4. The working clamping mechanism 56 has a working clamping table 58, and the working clamping table 58 is rotatable, and can be grounded at the wafer loading and unloading position A and the grinding unit 28 in the Y-axis direction by a moving mechanism (not shown). Move between the cut positions B.

The work chuck 58 has a holding surface 58a formed of a porous member such as porous ceramic. A clamp (clamping means) 68 for holding and fixing the four corners of the warped (curved) rectangular substrate is disposed at the four corners of the work chuck 58.

A waterproof cover 60 is disposed around the work clamp 58 and includes telescopic bladders 62, 64 covering the front end portion and the rear end portion of the waterproof cover 60 and the base 4. An operation panel 66 for the operator of the grinding device 2 to input grinding conditions and the like is disposed on the front side of the susceptor 4.

Referring to FIG. 2(A), the positive of the package substrate 11 such as a CSP substrate is shown. Face side perspective view. FIG. 2(B) is a perspective view showing the back side of the package substrate 11. A plurality of predetermined dividing lines 15 formed in a lattice shape are formed on the front surface of the substrate 13 such as a printed circuit board or a metal frame, and the wafer forming portion 17 is defined in each of the regions divided by the dividing planned line 15.

A plurality of electrodes are formed on the individual wafer forming portions 17. A semiconductor wafer 19 is adhered to the back side of the wafer forming portion 17 by a DAF (Die Attach Film). As shown in FIG. 2(C), the semiconductor wafer 19 mounted on the back side of the substrate 13 is sealed with a resin 21. The package substrate 11 has a size of, for example, 500 mm × 700 mm.

In the grinding apparatus 2 of the present embodiment, the surface of the surface 11a of the package substrate 11 is sucked by the work chuck 58 having the rectangular holding surface 58a, and the resin 21 on the back surface is exposed and the resin 21 is removed by the grinding wheel 38. Grinding to thin to a predetermined thickness.

One of the features of the grinding apparatus 2 of the present embodiment includes a cutting unit 44 that mounts the cutting blade 54 so as to be rotatable. Since the cutting unit 44 is provided, it is possible to reduce the internal stress of the package substrate 11 and correct the warpage by forming a cutting groove having a depth not reaching the depth of the grinding on the sealing resin 21 on the back surface 11b of the package substrate 11 by the cutting blade 54. (bending).

Another feature of the grinding apparatus of this embodiment is that a clamp 68 is provided at each of the four corners of the rectangular work chuck 58. By arranging the jig 68 on the work chuck 58, the four corners of the rectangular substrate such as the warped package substrate can be sandwiched, and then the rectangular substrate can be sucked and held by the work chuck 58 and applied to the sealing resin 21. A cutting step that forms a cutting groove to alleviate internal stresses.

Hereinafter, a grinding method of a rectangular substrate using the grinding apparatus 2 of the above-described embodiment will be described with reference to Figs. 3 to 5 . The grinding apparatus 2 of the present embodiment can particularly exhibit the effect when applied to a rectangular substrate having warpage (bending).

In the case where the package substrate 11 has warpage, before the sealing resin 21 of the package substrate 11 is ground by the grinding unit 28, a sealing step of cutting the sealing resin 21 of the package substrate 11 to relieve internal stress and correct warpage is performed.

In this cutting step, as shown in FIG. 3(A), the package substrate 11 is mounted on the work chuck 58 and the package substrate 11 is held by the clamp 68 to correct the warpage of the package substrate 11, and The surface of the surface 11a of the package substrate 11 is sucked by the holding surface 58a of the work chuck 58 to expose the sealing resin 21 of the back surface 11b.

Then, the cutting blade 54 that rotates at a high speed of the cutting unit 44 is cut toward the sealing resin 21 of the package substrate 11 to a depth that is not grounded, and the package substrate 11 is processed by the X-axis moving mechanism 26 to be applied to the package substrate. The cutting groove 23 is formed on the sealing resin 21 of 11.

A moving mechanism of the working chuck 58 (not shown) is formed by forming a plurality of cutting grooves on the sealing resin 21 of the package substrate 11 while feeding the working chuck 58 at a predetermined pitch in the Y-axis direction. twenty three.

When a plurality of cutting grooves 23 are formed on the sealing resin 21 of the package substrate 11, the internal stress of the sealing resin 21 of the package substrate 11 can be alleviated, and the warpage (bending) of the package substrate 11 can be corrected.

The formation of the cutting groove 23 by the cutting blade 54 of the cutting unit 44 can be formed in the longitudinal direction of the package substrate 11 as shown in FIG. 3(B). Alternatively, as shown in FIG. 3(C), the cutting grooves 23 may be formed in two directions of the longitudinal direction and the short side direction.

As shown in FIG. 3(C), when a plurality of cutting grooves 23 are formed in both the longitudinal direction and the short-side direction of the sealing resin 21 of the package substrate 11, the internal stress of the sealing resin 21 can be alleviated. The correction of the warpage of the package substrate 11 is more effective.

Since the warpage of the package substrate 11 is corrected by performing the cutting step, the jig 68 can be released, and the package substrate 11 can be sucked and held by the suction holding surface 58a of the work chuck 58.

Therefore, as shown in FIG. 4(A), a grinding step is performed which is a grinding unit 38 that sucks and holds the surface 11a side of the package substrate 11 with the working chuck 58 not shown, and rotates in the direction of the arrow b. The sealing resin 21 is pushed against the sealing resin 21 of the back surface 11b of the package substrate 11 to grind the sealing resin 21 to a predetermined thickness.

This grinding step will be described with reference to FIGS. 4(B) to 5(C). Further, in these figures, the work chuck 58 that sucks and holds the package substrate 11 is omitted.

Referring to Fig. 4(B), there is shown a schematic plan view showing the grinding method of the first embodiment. In the grinding method according to the first embodiment, when the operation chuck 58 holding the package substrate 11 is rotated at, for example, 300 rpm in the direction indicated by the arrow a, the grinding wheel 38 is oriented in the direction indicated by the arrow b. For example, the rotation is performed at 6000 rpm, and the grinding unit feed mechanism 16 is driven to bring the grinding vermiculite 42 of the grinding wheel 38 into contact with the sealing resin 21 of the back surface 11b of the package substrate 11.

Then, while the package substrate 11 is rocked in the Y-axis direction (moving back and forth) by the moving mechanism of the work chuck 58, the package substrate 11 is ground. The resin 21 is sealed. Since the package substrate 11 is ground while being shaken in the Y-axis direction, the entire sealing resin 21 of the back surface 11b of the package substrate 11 can be ground using the grinding wheel 38 having a small diameter.

Referring to Fig. 5(A), there is shown a schematic plan view showing a grinding method according to a second embodiment of the present invention. In the grinding method of the present embodiment, the grinding vermiculite 42 of the grinding wheel 38 is positioned to rotate the working chuck 58 at, for example, 300 rpm by the center of rotation of the package substrate 11 held on the working chuck 58. At this time, the grinding wheel 38 is rotated at, for example, 6000 rpm to grind the central portion of the back surface 11b of the package substrate 11.

After the center portion is ground, the grinding wheel 38 is moved away from the center of rotation of the package substrate 11 by the moving mechanism of the work chuck 58 (that is, while the work chuck 58 is moved in the direction of the arrow Y1), the package substrate 11 is ground. The entire back. In Fig. 5(A), 11c denotes a grinding area.

Referring to Fig. 5(B), there is shown a schematic plan view showing a grinding method according to a third embodiment of the present invention. In the grinding method of the present embodiment, the grinding wheel 38 is positioned by the moving mechanism of the work chuck 58 at the outermost periphery of the package substrate 11 held on the work chuck 58, and the work chuck 58 is made while being operated. The grinding wheel 38 is rotated in the direction of the arrow b at, for example, 6000 rpm while rotating in the direction of the arrow a at, for example, 300 rpm to grind the outermost circumference of the back surface 11b of the package substrate 11.

Next, while the work chuck 58 is moved in the direction of the arrow Y2 (the grinding wheel 38 is relatively moved from the outermost circumference of the package substrate 11 toward the rotation center), the entire surface of the back surface 11b of the package substrate 11 is ground. 11c in Fig. 5(B) indicates a grinding area.

Referring to Fig. 5(C), there is shown a schematic plan view showing a grinding method according to a fourth embodiment of the present invention. In the grinding method of the present embodiment, the grinding wheel 38 is positioned to be held along the working chuck 58 by the moving mechanism of the working chuck 58 and the X-axis moving mechanism 26 of the grinding unit 28. On the end portion of one of the side portions of the package substrate 11, the grinding wheel 38 is rotated in the direction of the arrow b at, for example, 6000 rpm without rotating the work chuck 58, and the work chuck 58 is moved in the direction of the arrow Y2. The sealing resin 21 of the back surface 11b of the package substrate 11 is ground. Next, the grinding unit 28 is indexed in the X-axis direction by the X-axis moving mechanism 26 to grind the unground region of the back surface 11b of the package substrate 11 in the same manner.

In each of the above embodiments, the example in which the grinding method of the present invention is applied to the rectangular package substrate 11 has been described, but the object to be ground is not limited thereto, and the grinding method of the present invention is not only applicable. The large-sized package substrate having warpage can be similarly applied to the application of grinding the front surface or the back surface of a large rectangular substrate having warpage.

2‧‧‧grinding device

4‧‧‧Base

6‧‧‧ pillar

8, 18‧‧‧ rails

10‧‧‧Z-axis moving block

12, 22‧‧‧ ball screw

14, 24‧‧ ‧ pulse motor

16‧‧‧Z-axis moving mechanism (grinding unit feed mechanism)

20‧‧‧Support block

26‧‧‧X-axis moving mechanism

28‧‧‧ Grinding unit (grinding means)

30, 50‧‧‧ spindle housing

32, 52‧‧‧ spindle

34‧‧‧Motor

36‧‧·wheel seat

38‧‧‧ grinding wheel

44‧‧‧Cutting unit (cutting means)

46‧‧‧Fixed components

48‧‧‧moving components

54‧‧‧Cutter

56‧‧‧Working table mechanism

58‧‧‧Working table

58a‧‧‧ Keep face

60‧‧‧Waterproof cover

62, 64‧‧‧ telescopic bladder

66‧‧‧Operator panel

68‧‧‧Clamps (clamping means)

A‧‧‧ wafer loading and unloading position

B‧‧‧ grinding position

X, Y, Z‧‧ Direction

Claims (5)

A grinding device is a grinding device for grinding a front side or a back surface of a rectangular substrate, characterized by comprising: a working clamping table having a holding surface for attracting and holding a rectangular substrate; and a grinding means for holding the grinding The grinding wheel of the rectangular substrate on the working clamping table is supported to be rotatable; the grinding feeding means grinds the grinding means in the vertical direction with respect to the holding surface of the working clamping table; the Y-axis moving means, The working clamping table and the grinding means are relatively moved between the loading and unloading area of the loading and unloading rectangular substrate and the grinding area of the grinding rectangular substrate in the Y-axis direction; and the X-axis moving means, the working clamping table and the working The grinding means relatively moves in an X-axis direction orthogonal to the Y-axis direction, the grinding wheel including a grinding wheel base, and a grinding verinite arranged in an annular shape on the outer peripheral surface of the lower surface of the grinding wheel base And setting the outer diameter of the ground vermiculite arranged in a ring shape to be smaller than the short side of the rectangular substrate. A grinding apparatus according to claim 1, wherein a clamping means for holding a rectangular substrate held on the working chuck is disposed on the working chuck. A grinding apparatus according to claim 1 or 2, further comprising cutting means for arranging the cutting blade for cutting the rectangular substrate held on the working table to be rotatable. A grinding method for a rectangular substrate, which is the grinding device using the claim 3 A grinding method for a rectangular substrate for grinding a rectangular substrate, characterized by comprising: a cutting step of forming a cutting groove having a depth not to be grounded by a cutting blade held by the cutting tool on a rectangular substrate held by the working table To alleviate the internal stress of the rectangular substrate; and a grinding step, after the cutting step is performed, grinding is held on the rectangular substrate of the working clamping table. The grinding method according to claim 4, wherein, when the cutting blade of the cutting means forms a cutting groove having a depth not reaching the grinding depth, the rectangular substrate is sandwiched by the clamping means, and after the cutting groove has been formed The clamping means is released.