JP2024098738A - Formation method of package unit and package unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a formation method of a package unit capable of reducing the probability of dust such as processing debris adhering to a plurality of chips even when chips are not picked up immediately after the wafer is divided.

SOLUTION: A plurality of first chips are provided in a first space surrounded by a first frame, a first sheet, and a third sheet, and a plurality of second chips are provided in a second space surrounded by a second frame, a second sheet, and a third sheet, thereby reducing the likelihood that dust adheres to the plurality of first chips and the plurality of second chips.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a method for forming a package unit containing multiple chips and the package unit.

Chips for devices such as ICs (Integrated Circuits) are essential components in various electronic devices such as mobile phones and personal computers. These chips are generally manufactured by dividing a wafer on which multiple devices are formed along the boundaries between the multiple devices using various processing equipment.

Then, multiple chips manufactured from the same wafer are loaded into a pickup device and individually picked up for mounting on, for example, a wiring board. Specifically, multiple chips are generally loaded into the pickup device in the form of a package unit formed by integrating the chips with a frame via tape.

For example, when a wafer is divided using a cutting device, the wafer is generally integrated with a frame via tape before the division (see, for example, Patent Document 1). In this case, the package unit formed by dividing the wafer without dividing the tape is then carried into a pickup device.

In addition, when a wafer is processed using a cutting device or laser processing device and then divided using a grinding device, typically, a wafer that is not integrated with a frame is divided to form multiple chips (see, for example, Patent Documents 2 and 3). In this case, a package unit formed by integrating multiple chips with a frame via tape is then carried into a pickup device.

Japanese Patent Application Publication No. 10-242083 JP 2010-183014 A JP 2020-21791 A

Because the processing equipment and pick-up equipment used to separate the wafers are installed in separate factories in remote locations, chip pick-up may not be performed immediately after the wafers are separated. In this case, dust from processing debris may adhere to the multiple chips contained in the package unit, which may deteriorate the performance of each chip.

In view of this, the object of the present invention is to provide a method for forming a package unit and a package unit that can reduce the likelihood of dust particles such as processing debris adhering to multiple chips, even if the chips are not picked up immediately after the wafer is divided.

According to one aspect of the present invention, a method for forming a package unit including a plurality of chips includes a first preparation step of preparing a first frame unit including a plurality of first chips formed by dividing a first wafer, a first sheet having one surface attached to the plurality of first chips, and a first frame having a circular first opening formed therein and having one surface attached to the one surface of the first sheet such that the plurality of first chips are positioned in the first opening, and a second sheet having a plurality of second chips formed by dividing a second wafer, a second sheet having one surface attached to the plurality of second chips, and a circular second opening having the same diameter as the first opening formed therein and having the plurality of second chips positioned in the second opening. A method for forming a package unit is provided, the method comprising: a second preparation step of preparing a second frame unit including a second frame unit having one surface fixed to the one surface of the second sheet so that a chip is positioned on the second frame unit; and a formation step of forming a package unit including the first frame, the first sheet, and the third sheet, and the second chips provided in a second space surrounded by the second frame, the second sheet, and the third sheet, by respectively fixing the one surface and the other surface of the third sheet to the other surface of the first frame and the other surface of the second frame after the first preparation step and the second preparation step.

In the present invention, the concentration of the inert gas in the first space and the second space is preferably higher than the concentration of the inert gas in air. Furthermore, the forming process is preferably carried out under an inert gas atmosphere. Alternatively, in the forming process, liquid nitrogen is preferably supplied between the first sheet and the third sheet and between the second sheet and the third sheet.

In addition, in the present invention, it is preferable to further include a cleaning step of cleaning the plurality of first chips and the plurality of second chips before the forming step.

In the present invention, the other surface of the first frame and the one surface of the third sheet are preferably heat-pressed, and the other surface of the second frame and the other surface of the third sheet are preferably heat-pressed. Furthermore, the third sheet is preferably a polyolefin sheet. Alternatively, the third sheet is preferably any one of a polyethylene sheet, a polypropylene sheet, and a polystyrene sheet. In addition, the forming step is performed in a state where the third sheet is heated to a predetermined temperature range, and the predetermined temperature range is preferably 120°C to 140°C when the third sheet is the polyethylene sheet, 160°C to 180°C when the third sheet is the polypropylene sheet, and 220°C to 240°C when the third sheet is the polystyrene sheet.

According to another aspect of the present invention, a package unit including a plurality of chips includes a first sheet having a surface attached to a plurality of first chips, a first frame having a circular first opening and a surface attached to the surface of the first sheet such that the plurality of first chips are positioned in the first opening, a second sheet having a surface attached to the plurality of second chips, and a second frame having a circular second opening having the same diameter as the first opening and a second opening in which the plurality of second chips are positioned. A package unit is provided that includes a second frame having one surface fixed to the one surface of the second sheet so that the chips are positioned thereon, and a third sheet having one surface fixed to the other surface of the first frame and the other surface fixed to the other surface of the second frame, the first chips being provided in a first space surrounded by the first frame, the first sheet, and the third sheet, and the second chips being provided in a second space surrounded by the second frame, the second sheet, and the third sheet.

In the package unit provided by the present invention, a plurality of first chips are provided in a first space surrounded by a first frame, a first sheet, and a third sheet, and a plurality of second chips are provided in a second space surrounded by a second frame, a second sheet, and a third sheet. This reduces the likelihood that dust will adhere to the plurality of first chips and the plurality of second chips.

FIG. 1 is a flow chart showing a schematic example of a method for forming a package unit including a plurality of chips. FIG. 2(A) is a perspective view showing a schematic example of a wafer, FIG. 2(B) is a perspective view showing a schematic example of a frame, and FIG. 2(C) is a perspective view showing a schematic example of a sheet. Figure 3(A) is an oblique view showing a wafer and a frame, each of which has one surface bonded to one surface of a sheet, and Figure 3(B) is a cross-sectional view showing a wafer and a frame, each of which has one surface bonded to one surface of a sheet. FIG. 4 is a partial cross-sectional side view showing a schematic view of how the wafer is divided along the intended dividing lines. FIG. 5A is an exploded perspective view that typically shows a package unit, and FIG. 5B is a cross-sectional view that typically shows the package unit.

An embodiment of the present invention will be described with reference to the attached drawings. FIG. 1 is a flow chart that shows a schematic example of a method for forming a package unit including multiple chips. In this method, first, a first frame unit is prepared in which multiple first chips formed by dividing a first wafer and a first frame are integrated via a first sheet (first preparation step S1).

This first frame unit is prepared, for example, by dividing the first wafer with one side of the first wafer and one side of the first frame affixed to one side of the first sheet. The first frame unit prepared in this manner is described below.

Figure 2(A) is a perspective view showing a schematic example of a wafer used as the first wafer. The wafer 11 shown in Figure 2(A) has a disk-shaped substrate 13 made of a single crystal semiconductor material such as silicon (Si), silicon carbide (SiC) or gallium nitride (GaN).

A notch 15 is formed on the outer edge of the substrate 13 to indicate a specific crystal orientation of the single crystal semiconductor that constitutes the substrate 13. In addition, an impurity region doped with impurities is provided on the surface 13a of the substrate 13.

Furthermore, the wafer 11 is divided into a plurality of regions by a plurality of planned division lines (first planned division lines) 17a each extending along the same direction (first direction) and a plurality of planned division lines (second planned division lines) 17b each extending along a second direction intersecting the first direction.

A device 19 is formed in each of the multiple regions. This device 19 is composed of a portion of the surface 13a side of the substrate 13 that includes an impurity region and a laminate including various insulating films and conductive films formed on the surface 13a of the substrate 13. Note that a similar laminate is not formed in the regions of the surface 13a of the substrate 13 that correspond to the multiple planned division lines 17a, 17b.

As a result, the surface of the wafer 11 has an uneven shape. Specifically, the regions where the devices 19 are formed are convex, and the regions corresponding to the planned division lines 17a, 17b are concave. On the other hand, the back surface of the wafer 11, i.e., the back surface 13b of the substrate 13, is generally flat.

There are no limitations on the material, shape, structure, size, etc. of the substrate 13. The substrate 13 may be made of materials such as ceramics, resin, and metal. Furthermore, the substrate 13 may not have an impurity region. Also, the outer edge of the substrate 13 may be formed with a flat portion, a so-called orientation flat, to indicate a specific crystal orientation instead of a notch.

Figure 2(B) is a perspective view showing a schematic example of a frame used as the first frame. The frame 21 shown in Figure 2(B) is made of a metal material such as aluminum or stainless steel, and has a circular opening 21a formed in the center.

The diameter of this opening 21a is larger than the diameter of the wafer 11, i.e., the diameter of the substrate 13. The thickness of the frame 21 is also larger than the thickness of the region of the wafer 11 where the devices 19 are formed. The outer edge of the frame 21 also includes four arc portions 21b that each extend in an arc, and four straight portions 21c that each extend in a straight line.

The four arcuate portions 21b are arranged so that their diameters are larger than the diameter of the opening 21a and their centers overlap a circle that coincides with the center of the opening 21a. The four arcuate portions 21b are also arranged at roughly equal angular intervals along the circumferential direction of the opening 21a.

The four straight line portions 21c are arranged so as to overlap a square whose center coincides with the center of the opening 21a. Each side of this square is larger than the diameter of the opening 21a and smaller than the diameter of the circle that overlaps with the four arc portions 21b. Each of the four straight line portions 21c is arranged between a pair of adjacent arc portions 21b along the circumferential direction of the frame 21.

Furthermore, a pair of frame cutouts 23a, 23b are formed between one of the four straight line portions 21c and a pair of arcuate portions 21b adjacent to this straight line portion 21c. The frame cutout 23a is formed so as to cut out the outer edge of the frame 21 at an acute angle. The frame cutout 23b is formed so as to cut out the outer edge of the frame 21 at a right angle.

The pair of frame cutouts 23a, 23b are used, for example, to indicate the orientation of the wafer 11 that is integrated with the frame 21. For example, the wafer 11 is integrated with the frame 21 so that the first direction is perpendicular to the straight portion 21c that is disposed between the pair of frame cutouts 23a, 23b.

Figure 2(C) is a perspective view showing a schematic example of a sheet used as the first sheet. The sheet 25 shown in Figure 2(C) has a disk-like shape. The diameter of this sheet 25 is larger than the diameter of the opening 21a of the frame 21 and smaller than each side of the square that overlaps with the four straight line portions 21c.

The sheet 25 is, for example, an adhesive tape having a flexible film-like substrate and an adhesive layer (glue layer) provided on one side of the substrate. Specifically, the substrate is made of polyolefin (PO), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polystyrene (PS), or the like. The adhesive layer is made of ultraviolet-curing silicone rubber, an acrylic material, an epoxy material, or the like.

Then, the surface (one surface) of the sheet 25 on which the adhesive layer is provided is pressed against one surface of the wafer 11, i.e., the back surface 13b of the substrate 13 and one surface of the frame 21. As a result, one surface of the wafer 11 and one surface of the frame 21 are fixed to one surface of the sheet 25.

The sheet 25 may have one side heat-pressed to one side of the wafer 11 and one side of the frame 21 without including an adhesive layer. In this case, the sheet 25 is, for example, a polyolefin-based sheet such as a polyethylene (PE) sheet or a polypropylene (PP) sheet, or a polystyrene sheet.

Furthermore, in this case, it is preferable to use a sheet having a storage modulus of 1.0×10 ⁻⁶ to 1.0×10 ⁻⁹ (Pa) at 10°C to 30°C and a storage modulus of 1.0× ^{10 −6} to 1.0×10 ⁻⁷ (Pa) at 80°C to 100°C.

Figure 3(A) is a perspective view showing a wafer 11 and a frame 21, each of which has one surface bonded to one surface of a sheet 25, and Figure 3(B) is a cross-sectional view showing a wafer 11 and a frame 21, each of which has one surface bonded to one surface of a sheet 25.

As shown in Figures 3(A) and 3(B), the central region of one side of the sheet 25 is fixed to one side of the wafer 11, and the peripheral region of one side of the sheet 25 is fixed to one side of the frame 21. In other words, the wafer 11 and the frame 21 are integrated so that the wafer 11 is positioned in the opening 21a of the frame 21.

Once the wafer 11 and frame 21 are integrated in this manner, the wafer 11 is divided along the planned division lines 17a and 17b to prepare the first frame unit. Figure 4 is a partial cross-sectional side view that shows the process of dividing the wafer 11 along the planned division lines 17a and 17b.

This division is performed by the cutting device 2 shown in FIG. 4. Note that the X-axis direction and the Y-axis direction shown in FIG. 4 are directions perpendicular to each other on a horizontal plane, and the Z-axis direction is a direction (vertical direction) perpendicular to the X-axis direction and the Y-axis direction.

The cutting device 2 shown in FIG. 4 has a chuck table 4. This chuck table 4 has a disk-shaped frame 4a made of ceramics or the like. The frame 4a has a disk-shaped bottom wall and a cylindrical side wall standing upright from the bottom wall.

In addition, a disk-shaped porous plate (not shown), for example made of porous ceramics, is fixed to the recess defined by the bottom wall and side wall of the frame body 4a. This porous plate has a diameter roughly equal to the inner diameter of the side wall of the frame body 4a. Furthermore, the porous plate communicates with a suction source (not shown), such as an ejector, via a through hole or the like formed in the bottom wall of the frame body 4a.

The upper surface of the porous plate also functions as the holding surface of the chuck table 4. Specifically, the wafer 11, which is integrated with the frame 21 via the sheet 25, is placed on the chuck table 4 via the sheet 25. When the suction source communicating with the porous plate is operated in this state, a suction force acts on the wafer 11 via the sheet 25, and the wafer 11 is held by the chuck table 4.

In addition, multiple clamps (not shown) are provided around the chuck table 4. These clamps are provided at approximately equal angular intervals along the circumferential direction of the chuck table 4. When the wafer 11 is held by the chuck table 4 as described above, the multiple clamps grip the frame 21 at a position lower than the holding surface of the chuck table 4.

The chuck table 4 and the multiple clamps are also connected to a rotational drive source (not shown) such as a motor. When this rotational drive source is operated, the chuck table 4 and the multiple clamps rotate around a rotation axis that passes through the center of the holding surface of the chuck table 4 and is aligned vertically.

The chuck table 4 and the clamps are also connected to a ball screw type X-axis direction movement mechanism (not shown). When this X-axis direction movement mechanism is operated, the chuck table 4 and the clamps move along the X-axis direction.

A cutting unit 6 is provided above the chuck table 4. This cutting unit 6 has a cylindrical spindle 8 that extends along the Y-axis direction. The base end of this spindle 8 is connected to a rotational drive source such as a motor (not shown), and an annular cutting blade 10 is attached to the tip end.

When this rotary drive source is operated, the cutting blade 10 rotates together with the spindle 8 around a straight line along the Y-axis direction as the axis of rotation. The cutting blade 10 is attached to the spindle 8 so that the straight line that serves as the axis of rotation of the spindle 8 passes through the center of the cutting blade 10.

The cutting unit 6 is also connected to a ball screw type Y-axis direction movement mechanism (not shown) and a ball screw type Z-axis direction movement mechanism (not shown). When the Y-axis direction movement mechanism is operated, the cutting unit 6 moves along the Y-axis direction, and when the Z-axis direction movement mechanism is operated, the cutting unit 6 moves along the Z-axis direction.

When the cutting device 2 divides the wafer 11 along the planned division lines 17a and 17b, the wafer 11 is first placed on the holding surface of the chuck table 4 via the sheet 25. Next, the wafer 11 is held by the chuck table 4, and the frame 21 is gripped by multiple clamps.

Then, for example, the chuck table 4 is rotated so that the planned division line 17a is parallel to the X-axis direction. Next, in a plan view, the cutting blade 10 is positioned in the X-axis direction as viewed from the planned division line 17a to be cut.

Then, the lower end of the cutting blade 10 is positioned at a height corresponding to the area of the sheet 25 that is located on the holding surface of the chuck table 4, i.e., at a position lower than the back surface 13b of the substrate 13 and higher than the holding surface of the chuck table 4. Next, the cutting blade 10 is rotated together with the spindle 8.

Next, while the cutting blade 10 is still rotating, the chuck table 4 is moved along the X-axis direction so that the lower end of the cutting blade 10 passes from one end of the substrate 13 to the other end in the X-axis direction. This forms a groove 11a that exposes the sheet 25 on its bottom surface, and the wafer 11 is divided along the planned division line 17a.

The above-described operations are then repeated until the wafer 11 is divided along the remaining planned division lines 17a and 17b. As a result, multiple chips are formed from the wafer 11, completing the first preparation step S1.

That is, a first frame unit is prepared that includes a plurality of first chips formed by dividing the wafer 11, a sheet 25 having one surface that is attached to the plurality of first chips, and a frame 21 having a circular opening 21a formed therein and having one surface that is attached to one surface of the sheet 25 so that the plurality of first chips are positioned in the opening 21a.

The first preparation step S1 may be performed by dividing the wafer 11 that is not integrated with the frame 21 to form a plurality of first chips, and then integrating the plurality of first chips with the frame 21 via the sheet 25.

For example, such a wafer 11 can be divided by using a cutting device 2 shown in FIG. 4 to form grooves on the front surface 13a of the substrate 13, the bottom surface of which is located inside the substrate 13, along the intended division lines 17a, 17b, and then grinding the back surface 13b of the substrate 13 using a known grinding device.

Alternatively, such division of the wafer 11 may be performed by forming modified portions, i.e., portions in which the crystal structure of the single crystal material constituting the substrate 13 is disrupted, on the front surface 13a of the substrate 13 along the intended division lines 17a, 17b using a known laser processing device, and then grinding the back surface 13b of the substrate 13 using a known grinding device.

After the first preparation step S1, a second frame unit is prepared in which a second frame and a plurality of second chips formed by dividing the second wafer are integrated via a second sheet (second preparation step S2). This second frame unit is prepared, for example, in the same manner as the first frame unit described above.

That is, the wafer 11 shown in FIG. 2(A), the frame 21 shown in FIG. 2(B), and the sheet 25 shown in FIG. 2(C) can be used as the second wafer, the second frame, and the second sheet, respectively.

The second frame unit is prepared, for example, by dividing the second wafer, which is integrated with the second frame via the second sheet as shown in Figures 3(A) and 3(B), along the intended division lines 17a and 17b in the cutting device 2 shown in Figure 4.

In this case, the first frame unit and the second frame unit may be prepared in parallel. Specifically, the division of the first wafer and the division of the second wafer may be performed after the integration of the first wafer and the first frame via the first sheet and the integration of the second wafer and the second frame via the second sheet are completed.

Alternatively, the second frame unit may be prepared by dividing a second wafer that is not integrated with the second frame to form a plurality of second chips, and then integrating the plurality of second chips with the second frame via a second sheet.

In this case, the first frame unit and the second frame unit may be prepared in parallel. Specifically, after the division of the first wafer and the division of the second wafer are completed, the integration of the first chips with the first frame via the first sheet and the integration of the second chips with the second frame via the second sheet may be performed.

After the first preparation process S1 and the second preparation process S2, a package unit is formed in which the first frame unit and the second frame unit are integrated via a third sheet (formation process S3). Figure 5(A) is an exploded perspective view that shows this package unit, and Figure 5(B) is a cross-sectional view that shows this package unit.

The forming process S3 is carried out, for example, in a thermocompression device (not shown) that has a table that has a flat upper surface and can rotate along its circumferential direction, and a roller that is provided above the table and has a heater installed inside.

In this thermocompression bonding device, first, the first frame unit 27a is placed on the table with the sheet 25 facing down. Next, the third sheet 29, which has a shape similar to that of the sheet 25 shown in FIG. 2(C), is placed on the first frame unit 27a so that the other surface of the frame 21 of the first frame unit 27a is in contact with one surface of the third sheet 29.

The third sheet 29 is, for example, a polyolefin sheet such as a polyethylene sheet or a polypropylene sheet, or a polystyrene sheet. Furthermore, it is preferable that a sheet having a storage modulus of 1.0×10 ⁻⁶ to 1.0×10 ⁻⁹ (Pa) at 10° C. to 30° C. and a storage modulus of 1.0×10 ⁻⁶ to 1.0×10 ⁻⁷ (Pa) at 80° C. to 100° C. is used as the third sheet 29.

Then, the second frame unit 27b is inverted and placed on the third sheet 29 so that the other surface of the frame 21 of the second frame unit 27b contacts the other surface of the third sheet 29. Next, while the frame 21 of the second frame unit 27b, the third sheet 29, and the frame 21 of the first frame unit 27a are pressed against the table by rollers, the heater is operated to heat the third sheet 29 to a predetermined temperature range.

This specified temperature range is 120°C to 140°C if the third sheet 29 is a polyethylene sheet, 160°C to 180°C if the third sheet 29 is a polypropylene sheet, and 220°C to 240°C if the third sheet 29 is a polystyrene sheet.

Next, the third sheet 29 is pressed by a roller and the table is rotated while it is heated to a predetermined temperature range. This causes one side and the other side of the third sheet 29 to be thermocompression bonded to the other side of the frame 21 of the first frame unit 27a and the other side of the frame 21 of the second frame unit 27b, respectively, completing the forming process S3.

That is, a package unit 35 is formed that includes a plurality of first chips 33a provided in a first space 31a surrounded by the frame (first frame) 21 and sheet (first sheet) 25 of the first frame unit 27a and the third sheet 29, and a plurality of second chips 33b provided in a second space 31b surrounded by the frame (second frame) 21 and sheet (second sheet) 25 of the second frame unit 27b and the third sheet 29.

In the package unit 35, a plurality of first chips 33a are provided in the first space 31a, and a plurality of second chips 33b are provided in the second space 31b. This reduces the likelihood that dust will adhere to the plurality of first chips 33a and the plurality of second chips 33b.

In addition, in the package unit 35, the third sheet 29 is shared to enclose both the multiple first chips 33a and the multiple second chips 33b. Therefore, in the package unit 35, it is possible to reduce the usage of the third sheet 29, which is a consumable item, compared to when separate third sheets 29 are used to enclose the multiple first chips 33a and the multiple second chips 33b.

The above is one aspect of the present invention, and the present invention is not limited to the above. For example, in the package unit 35, a double-sided tape having a flexible film-like base material and an adhesive layer (glue layer) provided on the peripheral region side of one surface of the base material and on the peripheral region of the other surface of the base material may be used as the third sheet 29.

Specifically, the base material is made of polyolefin, polyethylene terephthalate, polyvinyl chloride, polystyrene, etc., and the adhesive layer is made of ultraviolet-curing silicone rubber, acrylic material, epoxy material, etc.

The package unit 35 may be formed so that the concentration of the inert gas in the first space 31a and the second space 31b is higher than the concentration of the inert gas in the air. This makes it possible to suppress deterioration of the performance of the first chips 33a and the second chips 33b due to oxidation of the conductive film or the like contained in the device 19.

Examples of the inert gas include nitrogen ( _N2 ), carbon dioxide ( _CO2 ), and argon (Ar). The package unit 35 is formed by forming the package unit 35 in the thermocompression bonding apparatus described above under an inert gas atmosphere.

Alternatively, such a package unit 35 may be formed by supplying liquid nitrogen between the sheet 25 and the third sheet 29 of the first frame unit 27a and between the sheet 25 and the third sheet 29 of the second frame unit 27b when forming the package unit 35 in the thermocompression bonding device described above.

Specifically, the liquid nitrogen is first supplied onto the sheet 25 of the first frame unit 27a after the first frame unit 27a is placed on the table included in the above-mentioned thermocompression bonding device and before the third sheet 29 is placed on the first frame unit 27a. Furthermore, the liquid nitrogen is supplied onto the third sheet 29 after the third sheet 29 is placed on the first frame unit 27a and before the second frame unit 27b is placed on the third sheet 29.

The liquid nitrogen thus supplied is vaporized, and a portion of it remains in the first space 31a and the second space 31b. As a result, the nitrogen concentration in the first space 31a and the second space 31b becomes higher than the nitrogen concentration in the air.

In addition, a cleaning process may be carried out before the formation process S3 described above to clean the first tips 33a and the second tips 33b. This makes it possible to wash away dust adhering to the first tips 33a and the second tips 33b before the formation process S3.

In addition, the structures and methods of the above-described embodiments can be modified as appropriate without departing from the scope of the present invention.

2: Cutting device 4: Chuck table (4a: frame)
6: Cutting unit 8: Spindle 10: Cutting blade (10a: cutting edge)
11: Wafer (11a: Groove)
13: Substrate (13a: front surface, 13b: back surface)
15: Notch 17a, 17b: Planned division lines 19: Device 21: Frame (21a: Opening, 21b: Arc portion, 21c: Straight portion)
23a, 23b: Frame cutout 25: Sheet 27a: First frame unit 27b: Second frame unit 29: Third sheet 31a: First space 31b: Second space 33a: First chip 33b: Second chip 35: Package unit

Claims (10)

A method for forming a package unit including a plurality of chips, comprising the steps of:
a first preparation step of preparing a first frame unit including: a plurality of first chips formed by dividing a first wafer; a first sheet having one surface attached to the plurality of first chips; and a first frame having a circular first opening formed therein and having one surface attached to the one surface of the first sheet such that the plurality of first chips are positioned in the first opening;
a second preparation step of preparing a second frame unit including: a plurality of second chips formed by dividing a second wafer; a second sheet having one surface fixed to the plurality of second chips; and a second frame having one surface fixed to the one surface of the second sheet in which a circular second opening having the same diameter as the first opening is formed and in which the plurality of second chips are positioned in the second opening;
a forming step, after the first preparation step and the second preparation step, of fixing one surface and the other surface of a third sheet to the other surface of the first frame and the other surface of the second frame, respectively, to form a package unit including the plurality of first chips provided in a first space surrounded by the first frame, the first sheet, and the third sheet, and the plurality of second chips provided in a second space surrounded by the second frame, the second sheet, and the third sheet;
A method for forming a package unit comprising: The method for forming a package unit according to claim 1, wherein the concentration of the inert gas in the first space and the second space is higher than the concentration of the inert gas in air. The method for forming a package unit according to claim 2, wherein the forming process is carried out in an inert gas atmosphere. The method for forming a package unit according to claim 2, wherein liquid nitrogen is supplied between the first sheet and the third sheet and between the second sheet and the third sheet during the forming process. The method for forming a package unit according to claim 1, further comprising a cleaning step of cleaning the first chips and the second chips before the forming step. the other surface of the first frame and the one surface of the third sheet are thermally compressed together;
2. The method for forming a package unit according to claim 1, wherein the other surface of the second frame and the other surface of the third sheet are bonded by thermocompression. The method for forming a package unit according to claim 6, wherein the third sheet is a polyolefin-based sheet. The method for forming a package unit according to claim 6, wherein the third sheet is either a polyethylene sheet, a polypropylene sheet or a polystyrene sheet. The forming step is carried out in a state in which the third sheet is heated to a predetermined temperature range,
The method for forming a package unit according to claim 8, wherein the predetermined temperature range is 120°C to 140°C when the third sheet is the polyethylene sheet, 160°C to 180°C when the third sheet is the polypropylene sheet, and 220°C to 240°C when the third sheet is the polystyrene sheet. A package unit including a plurality of chips,
A plurality of first chips;
a first sheet having one surface attached to the plurality of first chips;
a first frame having one surface in which a circular first opening is formed and the first chips are positioned in the first opening, the first frame being fixed to the one surface of the first sheet;
A plurality of second chips;
a second sheet having one surface attached to the plurality of second chips;
a second frame having one surface fixed to the one surface of the second sheet such that a circular second opening having the same diameter as the first opening is formed and the plurality of second chips are positioned in the second opening;
a third sheet having one surface fixed to the other surface of the first frame and the other surface fixed to the other surface of the second frame,
the first chips are provided in a first space surrounded by the first frame, the first sheet, and the third sheet;
The second chips are provided in a second space surrounded by the second frame, the second sheet and the third sheet to form a package unit.

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