JP7055557B2 - Package substrate frame and package substrate grinding method - Google Patents

Description

The present invention relates to a frame for a package substrate used when grinding a package substrate, and a method for grinding a package substrate using the frame for the package substrate.

A package substrate can be obtained by mounting a device chip obtained by dividing a semiconductor wafer on a substrate and coating the device chip with a sealing material (mold resin) made of a resin. The package device manufactured from this package substrate is built in various electronic devices, and in recent years, as the electronic devices have become smaller and thinner, the package substrate is also required to be smaller and thinner. Therefore, a method of thinning the package substrate by grinding the mold resin of the package substrate with a grinding wheel is used.

As a grinding device for performing grinding, a grinding device for grinding a disk-shaped workpiece such as a semiconductor wafer is widely used, and by applying this grinding device to grinding a package substrate, a new grinding device is used. The introduction of a grinding device becomes unnecessary and the cost can be reduced. However, such a grinding device is configured on the assumption of grinding a disk-shaped workpiece, and in order to use it for grinding a package substrate, for example, a chuck table for holding the workpiece or a workpiece is to be machined. It is necessary to change the configuration of the transport unit that transports the object according to the shape of the package substrate and the like.

Patent Document 1 discloses a fixing jig for holding a package substrate when the package substrate is ground. This fixing jig has a rectangular shape having a plurality of recesses arranged corresponding to the position of the device chip and connected to the suction port in order to fix the package board in which a plurality of device chips are formed on the rectangular board. It has a base material.

Japanese Unexamined Patent Publication No. 2015-85514

When grinding a rectangular package substrate in a plan view using a grinding device that is supposed to grind a disk-shaped workpiece such as a semiconductor wafer, a grinding device such as replacing the chuck table with the above fixing jig. A large-scale remodeling is required, and the cost of grinding increases.

The present invention has been made in view of the above problems, and is a frame for a package substrate that enables the grinding process of the package substrate to be carried out and the cost of the grinding process to be reduced without major modification of the grinding apparatus. An object of the present invention is to provide a method for grinding a package substrate using the package substrate frame.

According to the present invention, when a package substrate having a surface of a substrate having a scrap area on the outer peripheral portion and the region excluding the scrap region is covered with a mold resin is sucked and held by a chuck table to grind the mold resin. A disk-shaped frame body having a diameter equal to or larger than the diameter of the suction surface of the chuck table having a circular suction surface for sucking the workpiece, and a frame body formed on the frame body. The package substrate includes an opening for exposing the mold resin and an eaves provided along the outer periphery of the opening and covering the end material region, and the eaves gradually toward the opening. A frame for a package substrate, which is formed to be thin, is provided.

The frame for a package substrate according to the present invention may be formed on the frame body and may have a mark portion indicating the direction of the frame body.

Further, according to the present invention, in the method for grinding a package substrate using the above-mentioned frame for a package substrate, the mold resin is exposed from the opening to the surface side of the frame body, and the end material region is the end material region. The frame unit forming step of positioning the package substrate so as to be covered with the eaves, fixing the package substrate to the frame body by attaching an adhesive tape to the back surface side of the frame body, and forming the frame unit, and the frame unit forming step. A method for grinding a package substrate is provided, which comprises a grinding step in which the frame unit is held by a chuck table and the molded resin exposed from the opening to the surface side of the frame body is ground by the grinding unit. In the frame unit forming step, the adhesive tape may be attached only to a part of the back surface of the frame body.

The frame for a package substrate according to the present invention is formed in a disk shape having a diameter larger than the suction surface of the chuck table provided in the grinding apparatus, and accommodates the package substrate of an arbitrary shape and size to accommodate the package substrate. It can be held on the chuck table. This makes it possible to grind a rectangular package substrate in a plan view using a grinding device that is supposed to grind a disk-shaped workpiece, without making major modifications to the grinding device. Grinding of package substrate can be carried out.

FIG. 1A is a perspective view showing a configuration example of a frame for a package substrate, and FIG. 1B is a cross-sectional view showing a configuration example of a frame for a package substrate. FIG. 2A is a perspective view showing how the frame for the package substrate is mounted on the package substrate, and FIG. 2B is a cross-sectional view showing how the frame for the package substrate is mounted on the package substrate. be. FIG. 3A is a perspective view showing a frame unit in a state where the frame for the package board is mounted on the package board, and FIG. 3B is a frame unit in a state where the frame for the package board is mounted on the package board. It is sectional drawing which shows. It is a perspective view which shows the structural example of a grinding apparatus. It is a front view which shows how the frame unit is conveyed by the transport unit. It is sectional drawing which shows how the mold resin is ground by a grinding unit. FIG. 7A is a perspective view showing a modified example of the frame for a package substrate, and FIG. 7B is a cross-sectional view showing a modified example of the frame for a package substrate. It is sectional drawing which shows the modification of the frame unit. It is sectional drawing which shows the state which the frame unit is held by the chuck table which has a convex part.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1A is a perspective view showing a configuration example of the package substrate frame 2 according to the present embodiment, and FIG. 1B is a cross-sectional view showing a configuration example of the package substrate frame 2. When the package substrate is ground, the package substrate frame 2 is held together with the package substrate on the holding surface of the chuck table provided in the grinding device, and has a function of fixing the package substrate on the chuck table.

In the following, as an example, a chuck table provided in a grinding device for grinding a disk-shaped workpiece such as a semiconductor wafer and having a circular holding surface corresponding to the shape of the workpiece has a rectangular shape in a plan view. A form for holding the package substrate will be described. By using the package substrate frame 2 according to the present embodiment, a grinding device configured assuming grinding of a disk-shaped workpiece can be used for grinding a rectangular package substrate in a plan view. It will be possible.

The package substrate frame 2 includes a disk-shaped frame body 4 which is formed of resin, metal, or the like and has a front surface 4a and a back surface 4b. A rectangular recess 4c is formed on the back surface 4b side of the frame body 4 in a plan view. The region located above the recess 4c reaches the surface 4a of the frame body 4 and is provided with a rectangular opening 4d in a plan view. The opening 4d is formed so that its width (length in the Y-axis direction) and depth (length in the X-axis direction) are smaller than those of the recess 4c.

Further, on the upper side of the recess 4c, a canopy-shaped eaves 6 projecting from the main body 4 toward the opening 4d is formed along the outer periphery of the opening 4d. Further, inside the recess 4c, a space 10 located below the eaves 6 and surrounded by the frame main body 4 and the eaves 6 is formed.

As will be described later, the recess 4c accommodates a part of the package substrate to be ground. In FIG. 1B, two recesses 4c and two openings 4d are formed in the frame body 4, but the number of the recesses 4c and the openings 4d depends on the size of the frame body 4 and the size of the package substrate. It can be increased or decreased accordingly.

When grinding the package substrate, the package substrate frame 2 is attached to the package substrate. FIG. 2A is a perspective view showing how the package substrate frame 2 is mounted on the package substrate 11, and FIG. 2B shows how the package substrate frame 2 is mounted on the package substrate 11. It is sectional drawing which shows.

The package substrate 11 includes a plate-shaped substrate 13 formed in a rectangular shape in a plan view, and a plurality of device chips (not shown) mounted on the surface 13a side of the substrate 13. The plurality of device chips mounted on the substrate 13 are made of resin and are covered with a mold resin 15 that seals the plurality of device chips. Further, the substrate 13 has an end material region 17 on the outer peripheral portion thereof, on which the mold resin 15 is not formed.

The recess 4c of the frame body 4 is formed so that its thickness (length in the Z-axis direction) substantially matches the thickness of the substrate 13 of the package substrate 11. Further, the recess 4c is formed so that its width and depth are larger than those of the substrate 13.

Further, the opening 4d is formed so that its width is larger than the width of the mold resin 15 and smaller than the width of the substrate 13, and the depth thereof is larger than the depth of the mold resin 15 and smaller than the depth of the substrate 13. To. Further, the opening 4d is formed so that its thickness is smaller than the thickness of the mold resin 15.

When grinding the package substrate 11, first, the package substrate frame 2 is mounted on the package substrate 11 to form a frame unit (frame unit forming step). Specifically, the front surface 13a side of the substrate 13 is inserted into the recess 4c from the back surface 4b side of the frame body 4, and the substrate 13 is housed in the recess 4c.

In this state, the adhesive tape 12 formed of epoxy resin or the like is attached to the back surface 4b of the frame body 4 and the back surface 13b of the substrate 13. As a result, the frame 2 for the package substrate and the package substrate 11 are fixed, and the frame unit is formed.

FIG. 3A is a perspective view showing a frame unit 19 in a state where the package substrate frame 2 is mounted on the package substrate 11, and FIG. 3B is a cross-sectional view showing the frame unit 19. When the substrate 13 of the package substrate 11 is housed in the recess 4c (see FIG. 1 (B)), a part of the upper side of the mold resin 15 is formed from the opening 4d (see FIG. 1 (B)) to the surface 4a of the frame body 4. It is exposed to the side and protrudes. Further, at least a part of the scrap region 17 of the substrate 13 is accommodated in the space 10 so as to be covered by the eaves 6, and the upper surface thereof is fixed in contact with the eaves 6.

As shown in FIG. 3B, the adhesive tape 12 may be attached to the back surface 4b of the frame body 4 so as to cover at least the recess 4c, and may not necessarily be attached to the entire back surface 4b of the frame body 4. good. By attaching the adhesive tape 12 only to a part of the back surface 4b of the frame main body 4, the adhesive tape 12 can be saved.

Although the example in which the package substrate 11 has a rectangular shape in a plan view has been described above, the present invention is not limited to this, and the package substrate 11 of any size and shape can be used. Further, the sizes and shapes of the recess 4c and the opening 4d can be appropriately changed according to the package substrate 11. Therefore, the package substrate frame 2 can accommodate the package substrate 11 having an arbitrary shape and size.

Further, as shown in FIGS. 1 (A), 2 (A), and 3 (A), the frame main body 4 may be formed with a mark portion 4e indicating the direction of the frame main body 4. By detecting the mark portion 4e with a sensor or the like, the orientation of the package substrate 11 on which the package substrate frame 2 is mounted can be grasped. The mark portion 4e can be used, for example, for adjusting the orientation of the frame unit 19 when the frame unit 19 is held by the chuck table of the grinding device or when the frame unit 19 is housed in the cassette of the grinding device.

Although FIGS. 1 (A), 2 (A), and 3 (A) show an example in which the mark portion 4e is a notch formed by cutting out the outer peripheral portion of the frame main body 4, the mark portion 4e is shown. There are no restrictions on the formation method of. For example, an orientation flat may be formed on the outer peripheral portion of the frame body 4 as the mark portion 4e, or a part of the frame body 4 may be colored and used as the mark portion 4e. By providing the notch and the orientation flat on the outer peripheral portion of the frame body 4, the frame unit 19 can be handled in the same manner as the semiconductor wafer.

Next, the frame unit 19 in which the frame 2 for the package substrate is mounted on the package substrate 11 is held by the holding surface of the chuck table provided in the grinding device, and is exposed from the opening 4d to the surface 4a side of the frame body 4. Grind the protruding mold resin 15 (grinding step). The package substrate 11 can be thinned by grinding the mold resin 15. Here, an example of using a grinding device provided with a chuck table having a circular holding surface for holding a disk-shaped workpiece will be described.

Hereinafter, a configuration example of a grinding device used for grinding the package substrate 11 will be described. FIG. 4 is a perspective view showing a configuration example of a grinding device 20 capable of grinding a disk-shaped workpiece such as a semiconductor wafer.

As shown in FIG. 4, the grinding device 20 includes a base 22 that supports each component of the grinding device 20. An opening 22a is formed on the front side of the upper surface of the base 22, and a transport unit 24 for transporting the frame unit 19 is provided in the opening 22a. Further, in the area further in front of the opening 22a, cassettes 26a and 26b capable of accommodating a plurality of frame units 19 are provided.

A position adjusting mechanism 28 for adjusting the position of the frame unit 19 is provided diagonally behind the opening 22a. The frame unit 19 carried out from the cassettes 26a and 26b by the transport unit 24 is arranged in the position adjusting mechanism 28, and the position is adjusted by the position adjusting mechanism 28. At a position adjacent to the position adjusting mechanism 28, a transport unit 30 that holds and turns the frame unit 19 is arranged. The frame unit 19 arranged in the position adjusting mechanism 28 is conveyed by the conveying unit 30.

FIG. 5 is a front view showing how the frame unit 19 is conveyed by the transfer unit 30. The transport unit 30 includes a disk-shaped base 32 and a plurality of suction pads 34 provided on the lower surface side of the base 32 to suck the frame unit 19. The frame unit 19 is held by the transport unit 30 by sucking the upper surface 4a of the main body frame 4 with the plurality of suction pads 34. By moving the base 32 in this state, the frame unit 19 is conveyed.

The mold resin 15 projects from the surface 4a side of the frame main body 4, and the suction pad 34 sucks the upper surface 4a of the main body frame 4 so as not to come into contact with the mold resin 15. The number of suction pads 34 is not limited, and for example, four suction pads 34 may be provided to suck and hold four outer peripheral portions of the main body frame 4.

Behind the transport unit 30 shown in FIG. 4, a turntable 36 that can rotate around a rotation axis parallel to the vertical direction is arranged. On the upper surface of the turntable 36, three chuck tables 38 for sucking and holding the frame unit 19 are provided. The number of chuck tables 38 arranged on the turntable 36 is not necessarily limited to three.

The transport unit 30 that sucks and holds the frame unit 19 by the suction pad 34 transports the frame unit 19 to the chuck table 38 so that the frame unit 19 is arranged at a predetermined position of the chuck table 38. When arranging the frame unit 19 on the chuck table 38, the frame unit 4e (see FIGS. 1 (A), 2 (A), and 3 (A)) provided on the frame main body 4 is used. 19 directions can be determined.

The chuck table 38 is connected to a rotation mechanism (not shown) such as a motor, and rotates around a rotation axis parallel to the vertical direction. The upper surface of the chuck table 38 is a holding surface for holding the frame unit 19. This holding surface is connected to a suction source (not shown) through a suction path (not shown) formed inside the chuck table 38. The frame unit 19 conveyed to the chuck table 38 is sucked by the negative pressure of the suction source acting on the holding surface of the chuck table 38.

Two columnar support structures 40 are provided behind the turntable 36. A Z-axis moving plate 44 is provided on the front side of the support structure 40 via a Z-axis moving mechanism 42. The Z-axis moving mechanism 42 includes a pair of Z-axis guide rails 46 parallel to the Z-axis direction, and a Z-axis moving plate 44 is slidably installed on the Z-axis guide rail 46.

A nut portion (not shown) is provided on the rear surface side (rear surface side) of the Z-axis moving plate 44, and a Z-axis ball screw 48 is screwed into this nut portion in parallel with the Z-axis guide rail 46. There is. A Z-axis pulse motor 50 is connected to one end of the Z-axis ball screw 48. When the Z-axis ball screw 48 is rotated by the Z-axis pulse motor 50, the Z-axis moving plate 44 moves in the Z-axis direction along the Z-axis guide rail 46.

A grinding unit 52 is provided on the front side of the Z-axis moving plate 44. The grinding unit 52 includes a spindle housing 54 fixed to a Z-axis moving plate 44. A spindle 66 (see FIG. 6) constituting a rotating shaft is rotatably supported on the spindle housing 54.

A grinding wheel 56 is attached to the lower end of the spindle. The grinding wheel 56 includes a cylindrical wheel base 70 (see FIG. 6) and a plurality of grinding wheels 72 (see FIG. 6) annularly arranged on the lower surface of the wheel base 70.

When the frame unit 19 is sucked and held by the chuck table 38, the turntable 36 rotates to position the frame unit 19 below the grinding unit 52. After that, the grinding unit 52 is lowered while the chuck table 38 and the grinding wheel 56 are rotated with each other, and the grinding wheel of the grinding wheel 56 is brought into contact with the mold resin 15 of the frame unit 19. Is ground.

A transport unit 58 that sucks and holds the ground frame unit 19 and turns is provided at a position adjacent to the transport unit 30. A cleaning mechanism 60 for cleaning the ground frame unit 19 carried out by the transport unit 58 is arranged in front of the transport unit 58. The frame unit 19 cleaned by the cleaning mechanism 60 is transported by the transport unit 24 and accommodated in the cassette 26b.

The orientation of the frame unit 19 can be determined by grasping the orientation of the frame unit 19 by the mark portion 4e provided on the frame main body 4 (see FIGS. 1 (A), 2 (A), and 3 (A)). They can be aligned and stored in the cassette 26b.

The package substrate 11 can be thinned by grinding the mold resin 15 formed on the package substrate 11 by the grinding unit 52 of the grinding apparatus 2. Hereinafter, the details of grinding the mold resin 15 will be described. FIG. 6 is a cross-sectional view showing how the mold resin 15 is ground by the grinding unit 52.

The upper surface of the chuck table 38 is a holding surface 38a for holding the frame unit 19. Further, the chuck table 38 is formed of porous ceramics or the like, and includes a disc-shaped suction portion 62 for sucking the frame unit 19, and the suction portion 62 is a suction source (a suction source) through a suction path 64 formed inside the chuck table 38. Not shown) is connected. The upper surface of the suction portion 62 is a circular suction surface 62a that sucks the workpiece, and the suction surface 62a constitutes a part of the holding surface 38a.

By applying the negative pressure of the suction source to the suction surface 62a in a state where the frame unit 19 is arranged so as to be in contact with the suction surface 62a, the frame unit 19 is held in contact with the suction surface 62a.

When the package substrate 11 is to be directly held by the holding surface 38a of the chuck table 38, if the back surface of the package substrate 11 is smaller than the suction surface 62a, a part of the suction surface 62a is exposed without being covered by the package substrate 11. do. Even if the negative pressure of the suction source is applied to the suction surface 62a in this state, the negative pressure leaks from a part of the exposed suction surface 62a, and the fixing of the package substrate 11 becomes insufficient. Therefore, depending on the size and shape of the package substrate 11, it may be difficult to hold the package substrate 11 by the chuck table 38.

Therefore, in the present embodiment, the frame 2 for the package substrate is configured by the frame body 4 having a size and shape capable of covering the entire surface of the suction surface 62a, and the frame unit 19 is configured by mounting the frame 2 on the package substrate 11. do. Specifically, the frame main body 4 is formed so that its diameter is equal to or larger than the diameter of the suction surface 62a. For example, if the diameter of the frame body 4 is substantially the same as the diameter of the holding surface 38a of the chuck table 38, the frame unit 19 can be handled in the same manner as the semiconductor wafer.

Then, the frame unit 19 is arranged on the holding surface 38a of the chuck table 38 so as to cover the suction surface 62a. As a result, the negative pressure of the suction source can be surely applied to the lower surface of the frame unit 19, and the package substrate 11 can be accurately sucked and held by the chuck table 38. By using the package substrate frame 2 in this way, the package substrate 11 can be held by the chuck table 38 regardless of its size and shape.

Further, the package substrate 11 may be warped due to the heat treatment at the time of forming the mold resin 15. When the mold resin 15 is ground while the package substrate 11 is warped, only a part of the surface of the mold resin 15 is locally ground, and the thickness of the mold resin 15 may vary. Therefore, it is preferable to correct the warp of the package substrate 11 when grinding the mold resin 15.

Here, when the package substrate 11 to which the frame for the package substrate 2 is mounted is held by the holding surface 38a of the chuck table 38, the end material region 17 of the substrate 13 is pressed against the holding surface 38a by the eaves portion 6. Therefore, the substrate 13 and the mold resin 15 are deformed so as to be arranged in parallel with the holding surface 38a, and the warp of the package substrate 11 is eliminated. As a result, the grinding process can be performed with high accuracy.

A grinding unit 52 is arranged above the chuck table 38. The spindle housing 54 (see FIG. 4) of the grinding unit 52 accommodates the spindle 66, and a disk-shaped mount 68 is fixed to the lower end of the spindle 66.

A grinding wheel 56 having substantially the same diameter as the mount 68 is mounted on the lower surface of the mount 68. The grinding wheel 56 includes a cylindrical wheel base 70 made of a metal material such as stainless steel or aluminum. A plurality of grinding wheels 72 are arranged on the lower surface of the wheel base 70.

A rotation drive source (not shown) such as a motor is connected to the upper end side (base end side) of the spindle 66, and the grinding wheel 56 rotates in parallel in the vertical direction due to the force generated from this rotation drive source. Rotate around the axis. A nozzle (not shown) for supplying a grinding liquid such as pure water to the frame unit 19 is provided inside or in the vicinity of the grinding unit 52.

When grinding the mold resin 15 of the package substrate 11, the chuck table 38 is moved below the grinding unit 52 while the frame unit 19 is held by the chuck table 38. Then, the chuck table 38 and the grinding wheel 56 are rotated, respectively, and the spindle 66 is lowered while supplying the grinding fluid to the frame unit 19.

Then, when the grinding wheel 72 comes into contact with the mold resin 15, the mold resin 15 is ground. The lowering speed (lowering amount) of the spindle housing 54 is appropriately adjusted so that the lower surface of the grinding wheel 72 is pressed against the mold resin 15 with an appropriate force. In this way, the package substrate 11 can be thinned.

As described above, the package substrate frame 2 according to the present embodiment can accommodate the package substrate 11 having a size and shape different from that of the chuck table 38, and can hold the package substrate 11 on the chuck table 38. This makes it possible to perform machining such as grinding a rectangular package substrate 11 in a plan view using a grinding device 20 that is supposed to grind a disk-shaped workpiece, and the grinding device 20 can be extensively modified. Grinding of the package substrate 11 can be performed without performing the grinding process.

Although FIG. 1 shows a configuration example in which the frame body 4 and the eaves 6 are integrated, the frame body 4 and the eaves 6 separately manufactured may be fixed to the frame body 4. FIG. 7A is a perspective view showing a modified example of the package substrate frame 2, and FIG. 7B is a cross-sectional view showing a modified example of the package substrate frame 2.

In the package substrate frame 2 shown in FIGS. 7A and 7B, a plate-shaped eaves 6 formed separately from the frame body 4 is fixed to the upper surface 4a side of the frame body 4. The frame body 4 includes an opening 4f extending from the front surface 4a to the back surface 4b. Further, the eaves 6 is formed of a resin, metal, or the like in a rectangular shape in a plan view, and has an opening 6c extending from the front surface 6a to the back surface 6b of the eaves 6. The opening 4f and the opening 6c are formed in a rectangular shape in a plan view.

The eaves 6 is formed so as to have a width and depth larger than that of the opening 4f formed in the frame body 4, and the opening 6c is formed so as to have a width and depth smaller than that of the opening 4f. To. Then, the eaves portion 6 is fixed to the surface 4a side of the frame body 4 along the outer peripheral portion of the opening portion 4f so that the opening portion 6c overlaps with the opening portion 4f in a plan view. There is no limitation on the method of fixing the eaves 6 to the frame body 4. For example, the eaves 6 can be fixed to the frame body 4 by using an adhesive.

Further, the dimensions of the frame body 4 and the eaves 6 are set according to the dimensions of the package substrate 11 housed in the package substrate frame 2. Specifically, the frame body 4 is formed so that its thickness substantially matches the thickness of the substrate 13 of the package substrate 11. In the eaves 6, the width of the opening 6c is larger than the width of the mold resin 15 and smaller than the width of the substrate 13, and the depth of the opening 6c is larger than the depth of the mold resin 15 and smaller than the depth of the substrate 13. Is formed like this. The thickness of the eaves 6 is less than the thickness of the mold resin 15.

When the package board frame 2 is mounted on the package board 11, the board 13 is housed in the opening 4f of the frame body 4, and a part of the upper side of the mold resin 15 is formed from the opening 6c of the eaves 6 to the surface of the frame body 4. It is exposed and protrudes to the 4a side. That is, the opening 4f corresponds to the recess 4c in FIG. 1 (B), and the opening 6c corresponds to the opening 4d in FIG. 1 (B). Further, at least a part of the scrap region 17 of the substrate 13 is accommodated in the space 10 so as to be covered by the eaves 6, and the upper surface thereof is fixed in contact with the eaves 6.

As described above, by manufacturing the eaves 6 separately from the frame body 4, a plurality of package board frames 2 corresponding to package boards 11 of various sizes and shapes can be obtained without changing the dimensions of the frame body 4. It can be easily obtained.

For example, a plurality of frame bodies 4 having the same size and shape of the openings 4f and a plurality of eaves 6 having different sizes or shapes of the openings 6c are prepared. Then, by fixing the eaves 6 having different sizes or shapes of the openings 6c to the plurality of frame main bodies 4, a plurality of package substrate frames 2 capable of accommodating the package substrates 11 having different dimensions can be obtained. In this case, since it is not necessary to change the dimensions of the frame body 4 according to the dimensions of the package substrate 11, the manufacturing cost of the frame 2 for the package substrate can be reduced.

Further, FIG. 2 shows the package substrate 11 in which the mold resin 15 covering the device chip is formed on the surface 13a side of the plate-shaped substrate 13, but the embodiment of the package substrate 11 is not limited to this. For example, a flexible substrate may be used as the substrate 13, or a device chip covered with a mold resin may be mounted on both the front surface 13a side and the back surface 13b side of the substrate 13. FIG. 8 is a cross-sectional view showing a modified example of the frame unit 19 in which the package substrate frame 2 is mounted on the package substrate 11 different from FIG.

The package substrate 11 of the frame unit 19 shown in FIG. 8 has a flexible substrate 21 formed of a resin or the like and having flexibility. A mold resin 23a that covers a device chip (not shown) mounted on the front surface 21a side is formed on the front surface 21a side of the flexible substrate 21, and a device mounted on the back surface 21b side is formed on the back surface 21b side of the flexible substrate 21. A mold resin 23b is formed to cover the chip (not shown). For example, a device chip having a function such as a sensor can be mounted on the front surface 21a side, and a device chip having a function such as a memory can be mounted on the back surface 21b side.

When grinding the mold resin 23a, first, the package substrate 11 is arranged inside the recess 4c of the frame main body 4. The frame body 4 is formed so that its thickness is thinner than that of the package substrate 11. Then, with a part of the mold resin 23a protruding from the opening 4d of the frame body 4 toward the front surface 4a, the adhesive tape 12 is attached to the back surface 4b and the mold resin 23b of the frame body 4 to form the frame unit 19. do.

After that, the frame unit 19 is held by the chuck table 38 of the grinding device 20 (see FIG. 6), and the mold resin 23a is ground and thinned. Grinding of the mold resin 23b can also be performed by the same method.

Here, when the flexible substrate 21 having flexibility is used for the package substrate, the end portion of the flexible substrate 21 is deformed and bent toward the mold resin side 23a when the mold resin 23a is ground, which hinders the grinding process. There is. However, in the present embodiment, as shown in FIG. 8, when the package substrate frame 2 is mounted on the package substrate 11, the eaves 6 is in contact with the end of the flexible substrate 21, and the end of the flexible substrate 21 is on the lower side (molded). It is pressed against the resin 23b side). Therefore, it is possible to prevent the end portion of the flexible substrate 21 from being exposed to the mold resin 23a side, and the grinding process can be smoothly performed.

Further, the eaves 6 of the package substrate frame 2 shown in FIG. 8 is formed so that the lower surface thereof is inclined with respect to the surface 4a of the frame main body 4 so as to gradually become thinner toward the opening 4d. As a result, the area of the eaves portion 6 supported by the main body frame 4 is increased, and the rigidity of the eaves portions 6 can be increased. This structure is particularly effective because, for example, when the mold resin 23a is relatively thin (100 μm or less, etc.) and the eaves 6 needs to be designed to be thin accordingly, it is possible to suppress a decrease in the rigidity of the eaves 6. be.

When the mold resin 23a is formed thin, instead of thinning the eaves 6, a convex portion is provided on the chuck table holding the frame unit 19, and the package substrate 11 is arranged on the convex portion. Grinding can also be performed by increasing the apparent thickness of the mold resin 23a. FIG. 9 is a cross-sectional view showing a state in which the frame unit 19 is held by the chuck table 38 having the convex portion 38b.

The chuck table 38 shown in FIG. 9 has a convex portion 38b protruding toward the holding surface 38a, corresponding to a position where the package substrate 11 is held. The convex portion 38b supports the package substrate 11 and is formed so that its width and depth are smaller than those of the concave portion 4c of the frame body 4.

When grinding the mold resin 23a, the frame unit 19 is held by the chuck table 38 so that the back surface side of the package substrate 11 is in contact with the convex portion 38b. At this time, the convex portion 38b is arranged inside the concave portion 4c of the frame main body 4, and the package substrate 11 is arranged above the convex portion 38b by the thickness of the package substrate frame 2. As a result, a part of the mold resin 23a is exposed from the opening 4c to the upper surface 4a side.

By providing the convex portion 38b on the chuck table 38 in this way, even when the mold resin 23a is formed relatively thin, the mold resin 23a is packaged without changing the thickness of the eaves portion 6. It can be exposed from the substrate frame 2.

Although FIG. 9 shows an example in which the convex portion 38b is composed of a part of the chuck table 38, the convex portion 38b manufactured separately from the chuck table 38 is fixed to the holding surface 38a of the chuck table 38. You may.

In addition, the structure, method, and the like according to the above-described embodiment can be appropriately modified and implemented as long as they do not deviate from the scope of the object of the present invention.

2 Frame for package board 4 Frame body 4a Front side 4b Back side 4c Recess 4d Opening 4e Marking part 4f Opening 6 Eaves 6a Front side 6b Back side 6c Opening 10 Space 12 Adhesive tape 20 Grinding device 22 Base 22a Opening 24 , 26b Cassette 28 Position adjustment mechanism 30 Transport unit 32 Base 34 Suction pad 36 Turntable 38 Chuck table 38a Holding surface 38b Convex 40 Support structure 42 Z-axis movement mechanism 44 Z-axis movement plate 46 Z-axis guide rail 48 Z-axis ball screw 50 Z-axis pulse motor 52 Grinding unit 54 Spindle housing 56 Grinding wheel 58 Conveying unit 60 Cleaning mechanism 62 Suction part 62a Suction surface 64 Suction path 66 Spindle 68 Mount 70 Wheel base 72 Grinding grindstone 11 Package board 13 Board 13a Front surface 13b Back side 15 Mold resin 17 Scrap area 19 Frame unit 21 Flexible substrate 23a, 23b Mold resin

Claims (4)

A frame for a package substrate used when a package substrate having a scrap region on the outer periphery and the region excluding the scrap region on the surface of the substrate is covered with a mold resin by suction and holding by a chuck table to grind the mold resin. And,
A disk-shaped frame body having a diameter equal to or larger than the diameter of the suction surface of the chuck table having a circular suction surface for sucking the workpiece, and a disk-shaped frame body.
An opening formed in the frame body to expose the mold resin of the package substrate, and
It is provided with an eaves portion provided along the outer periphery of the opening and covering the scrap area .
The eaves portion is a frame for a package substrate, which is formed so as to gradually become thinner toward the opening portion . The frame for a package substrate according to claim 1, wherein the frame is formed on the frame body and includes a mark portion indicating the direction of the frame body. A method for grinding a package substrate using the package substrate frame according to claim 1 or 2.
The package substrate is positioned so that the mold resin is exposed from the opening to the front surface side of the frame body and the scrap area is covered by the eaves, and the adhesive tape is attached to the back surface side of the frame body. In the frame unit forming step of fixing the package substrate to the frame body to form the frame unit,
A method for grinding a package substrate, comprising: holding the frame unit by the chuck table and grinding the mold resin exposed from the opening to the surface side of the frame body by the grinding unit. The method for grinding a package substrate according to claim 3, wherein in the frame unit forming step, the adhesive tape is attached only to a part of the back surface of the frame body.

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