TWI700735B - Component chip manufacturing method - Google Patents

Abstract

Provided is a method for manufacturing device wafers, which can arrange a plurality of devices in a row without leaving gaps.

A method for manufacturing an element wafer is to form an element wafer of an element in each area of the surface divided by a plurality of predetermined dividing lines having a predetermined width that intersect each other to manufacture an element wafer; , Equipped with: a reforming layer forming step, which is to place the condensing point of the laser beam with a wavelength that is transparent with respect to the element wafer to the inside of the element wafer, and follow the beam from the back of the element wafer The two edges in the width direction of the planned dividing line are irradiated to form a plurality of layers of two modified layers parallel to each other in the vertical direction; and the dividing step is performed after the modified layer forming step is applied to the element wafer The external force divides the element wafer into a plurality of element wafers using the modified layer as the starting point of breaking; in the modified layer forming step, the modified layer on the back side is formed to be more inclined to the device than the modified layer on the surface side The position of the side; the side surface of the element wafer broken along the plurality of modified layers, the surface side is the most protruding.

Description

Component chip manufacturing method

The present invention relates to a method for manufacturing device chips used in long line sensors or LED printer heads.

As electronic parts using element wafers obtained by dividing element wafers such as semiconductor wafers or optical element wafers, there are electronic parts such as long line sensors or LED printer heads.

As a feature of these electronic components, the manufactured component bus wafers are arranged in a row without gaps and the distance between the component wafers is reduced to the limit to form an electronic component in which a plurality of components are neatly arranged.

In order to prevent missing sensing or missing printing, it is important for the components to be arranged as continuous as possible without gaps. When manufacturing the component chip, it is necessary to divide the component wafer as far as possible without leaving the dividing line of the component wafer. It is important.

In addition, when arranging the wafers in a row, it is important that the adjacent elements cannot have a gap between each other, and there are no protrusions left on the side of the wafer. In order to meet this requirement, it is proposed to use an oblique slope. The cutting insert changes the angle and cuts the two edges of the predetermined dividing line in the width direction (for example, see Japanese Patent Laid-Open No. 2010-073821 or Japanese Patent Laid-Open No. 2007-273743).

[Prior Technical Literature] 〔Patent Literature〕

[Patent Document 1] Japanese Patent Application Publication No. 2010-073821

[Patent Document 2] Japanese Patent Application Publication No. 2007-273743

However, in the conventional method using cutting inserts, the cost of preparing a dedicated cutting device for tilting the cutting insert is necessary. Because of chipping (chipping, missing corners), in order to prevent chipping of components, It is necessary for the distance between the element and the cutting blade to be provided with a margin, so there is a limit to the arrangement of a plurality of elements in a row.

The present invention was created in view of such problems, and its purpose is to provide a method for manufacturing a device chip, which can arrange a plurality of devices in a row without gaps.

According to the present invention, there is provided a method for manufacturing a device chip, which forms the device chip in each area of the surface divided by a plurality of predetermined division lines having a predetermined width that cross each other. Round, manufacturing element wafers; characterized by comprising: a holding step of holding the element wafer by making the surface side of the element wafer face the holding surface of the chuck bed; the reforming layer forming step is performed after the holding After the step, place the condensing point of the laser beam with a transparent wavelength with respect to the element wafer to the inside of the element wafer, and move the beam from the back of the element wafer along the width direction of the planned dividing line Irradiating the two edges of the device to form a plurality of layers of two modified layers parallel to each other in the vertical direction; and the dividing step is to apply external force to the device wafer after the modified layer forming step is performed, and the modified layer The element wafer is divided into a plurality of element wafers for the starting point of breaking; in the reforming layer forming step, the reforming layer on the back side is formed to a position deviated from the reforming layer on the front side to the device side, and the The modified layer on the back side is formed with a plurality of layers; the modified layer on the back side includes the modified layer stacked in the vertical direction; the modified layer formed next to the modified layer on the surface side is The modified layer formed to overlap the surface side in the thickness direction of the element wafer; the side surface of the element wafer broken along the plurality of modified layers is the most prominent on the surface side.

According to the method for manufacturing a component wafer of the present invention, a plurality of modified layers are formed inside the component wafer with a laser beam to break the component wafer into one component wafer, and the surface side is formed along the planned dividing line The two modified layers are formed from the two edges of the planned dividing line toward the center, and the modified layers are formed along both edges on the back side.

Therefore, in the element wafer in which the element wafer is divided, the side surface of the wafer is inclined from the surface to the obliquely lower side (the center side of the wafer). When the wafers are connected to each other, no gap is formed between the adjacent wafers on the device surface side. Therefore, when arranging a plurality of element wafers in a row, the plurality of element wafers can be arranged in a row with almost no gaps between adjacent elements.

In addition, since the modified layer formed on the element wafer is divided into a plurality of element wafers from the breaking point, chipping does not occur, and it can be broken into parts as close as possible to the edge of the planned division line. The effect of the component chip.

10‧‧‧Chuck bed

11‧‧‧Semiconductor Wafer

13, 13a, 13b‧‧‧Preparation line (cutting path)

14‧‧‧Concentrator

15‧‧‧Component

20‧‧‧Splitting device

21‧‧‧Modified layer

22‧‧‧Expansion drum

23‧‧‧Component chip

24‧‧‧Frame keeping means

25‧‧‧Cut Road Department

26‧‧‧Frame holding member

27‧‧‧Line sensor

[Fig. 1] A perspective view of the front side of a semiconductor wafer.

[Fig. 2] is a perspective view of a state in which the surface side of the semiconductor wafer is attached to the spreading tape, which is an adhesive tape attached to the ring frame as the outer peripheral part.

[Fig. 3] is a partial cross-sectional side view illustrating the step of forming a modified layer.

[FIG. 4] An enlarged view of a part of the back side of the semiconductor wafer explaining the position where the modified layer is formed in the modified layer forming step.

[Fig. 5] Fig. 5(A) is a cross-sectional view showing the method of forming a modified layer according to the first embodiment of the present invention; Fig. 5(B) is a cross-sectional view showing the method of forming a modified layer according to the second embodiment.

[Fig. 6] Figs. 6(A) and 6(B) are partial cross-sectional side views showing the dividing step; Fig. 6(C) is an enlarged view of part A of Fig. 6(B).

[Fig. 7] is a cross-sectional view of a line sensor in which a plurality of element chips are arranged in a row.

Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. Referring to FIG. 1, there is shown a perspective view of a semiconductor wafer (element wafer). The element wafer 11 shown in FIG. 1 is made of, for example, a silicon wafer with a thickness of 300 μm. On the surface 11a, a plurality of planned dividing lines (dicing lanes) 13 are formed in a grid shape, and at the same time, a plurality of divided Elements 15 such as CCD and CMOS are formed in each area divided by the predetermined line 13.

The semiconductor wafer 11 thus constituted is provided with an element area 17 in which a plurality of elements 15 are formed and an outer peripheral area 19 surrounding the element area 17 on its surface 11a. 11b is the back surface of the semiconductor wafer 11.

The wafer to be processed in the method of manufacturing the element wafer of the present invention is not limited to the semiconductor wafer 11 shown in FIG. 1, but also includes forming an epitaxial layer (light emitting layer) such as gallium nitride on a sapphire substrate. An element wafer such as an optical element wafer.

In the method of manufacturing the element wafer according to the embodiment of the present invention, before processing, as shown in FIG. 2, the surface 11a of the element wafer 11 is attached to the surface 11a, and the outer periphery is attached to the ring frame F using adhesive tape The formed stretched tape T. Therefore, during processing, the back surface 11b of the element wafer 11 is exposed.

In the manufacturing method of the element wafer of this embodiment, first, the holding step is performed to hold the element wafer 11 by making the surface 11a side of the element wafer 11 face the holding surface of the chuck table of the laser processing apparatus.

That is, as shown in FIG. 3, the chuck bed 10 of the laser processing apparatus is used to suck and hold the element wafer 11 through the spreading tape T, and the back surface 11b of the element wafer 11 is exposed upward. Next, the ring frame F is clamped by the clamp 12 and fixed.

In the state where the element wafer 11 is held by the chuck table 10, the reforming layer forming step is performed. The condenser 14 of the lightning beam generation unit is used to reduce the wavelength (for example, 1064nm) pulsed laser beam, the position is to the inside of the wafer 11 corresponding to the planned dividing line 13, the laser beam is irradiated from the back side 11b of the wafer 11, and the chuck bed 10 is directed toward the arrow X1 Processing and feeding are performed in the X2 direction or the X2 direction, and multiple modified layers 21 are formed inside the wafer.

The position of the modified layer formed in this modified layer forming step is described with reference to FIG. 4. In FIG. 4, it is illustrated that the planned dividing line on the side where the components need to be closely arranged is referred to as 13a, and the planned dividing line on the side where the components are not required to be closely arranged as 13b.

In the planned dividing line 13a, two modified layers 21 are formed inside the wafer 11 along the two edges in the width direction of the planned dividing line 13a. The formation of the modified layer 21 in this direction is to form a plurality of layers in the thickness direction of the wafer 11.

Regarding the planned dividing line 13b, one modified layer 21 is formed inside the wafer along the approximate center of the planned dividing line 13b. The formation of the reforming layer 21 in this direction also forms a plurality of layers in the thickness direction of the wafer 11.

Referring to Figure 5, the steps of forming the modified layer are further detailed Explain it. Fig. 5(A) is a cross-sectional view showing a step of forming a modified layer in the first embodiment. In the modified layer forming step of the first embodiment, first, on the side close to the surface 11a of the element wafer 11, two parallel modified layers are formed at a predetermined distance from both edges of the planned dividing line 13a.质层21。 Quality layer 21.

Next, when the condensing point P of the thunder ray beam condensed by the condenser 14 is raised to the position on the back side 11b side of the wafer 11, two parallel modified lines are formed along the two edges of the planned dividing line 13a.质层21。 Quality layer 21. Furthermore, the condensing point P of the thunder ray beam is positioned on the back side 11b side of the wafer 11, and two modified layers 21 are formed parallel to each other so as to overlap the modified layer 21 formed earlier in the vertical direction . The wafer 11 is fed through the index, and two modified layers 21 are formed along the adjacent planned dividing line 13a.

Furthermore, in the embodiment shown in FIG. 5(A), one modified layer 21 on the side close to the surface 11a of the wafer 11 is formed, and two modified layers 21 on the back surface 11b side overlapping in the vertical direction are formed. ; But the number of layers of the modified layer 21 is not limited to this, it is also possible to form two or more modified layers 21 on the surface 11a side, only one modified layer 21 on the back surface 11b side, or three or more layers.

Regarding the planned dividing line 13b, since it is not necessary to closely arrange the sides of the elements, a plurality of modified layers 21 are formed as if they overlap in the vertical direction along the center of the planned dividing line 13b.

Referring to FIG. 5(B), there is shown a cross-sectional view showing a step of forming a modified layer according to a second embodiment of the present invention. In the modified layer of this embodiment In the forming step, the modified layer 21 on the surface 11a side of the wafer 11 and the modified layer 21 to be formed next are overlapped in the thickness direction of the wafer 11.

The length of the overlap is preferably about 30 μm. The method of forming by overlapping the modified layer 21 in this manner confirmed that the desired cracks that propagated from the modified layer 21 can be formed reliably.

The processing conditions in the step of forming the modified layer can be set as follows, for example.

Light source: LD excitation Q switch Nd: YVO4 pulse laser

Wavelength: 1064nm

Average output: 0.2W

Repetition frequency: 80kHz

Spot diameter: Φ1μm

Processing feed rate: 100nm/s

After the reforming layer forming step is performed, the dividing step is performed to apply an external force to the element wafer 11, and the element wafer 11 is divided into a plurality of element wafers using the reforming layer 21 as a breaking point.

Refer to Figure 6 for the description of the segmentation step. 6(A), the dividing device 20 includes an expansion roller 22 and a frame holding means 24 for holding the ring frame F. The expansion roller 22 has an inner diameter smaller than the inner diameter of the ring frame F and larger than the outer diameter of the wafer 11 attached to the spreading tape T attached to the ring frame F.

The frame holding means 24 uses a ring-shaped frame holding member 26. It is composed of a plurality of clamps 28 as fixing means arranged on the outer periphery of the frame holding member 26. The upper surface of the frame holding member 26 forms a mounting surface 26a on which the ring-shaped frame F is mounted, and the ring-shaped frame F is mounted on the mounting surface 26a.

Next, the ring-shaped frame F placed on the placement surface 26 a is fixed to the frame holding member 26 by the clamp 28. The frame holding means 24 configured in this way is connected to the piston rod 32 of the air cylinder 30, and the frame holding member 26 is moved in the up and down direction via the actuation of the air cylinder 30.

Regarding the wafer dicing step performed by using the dicing device 20 configured in this way, refer to FIGS. 6(A) to 6(C) for description. As shown in FIG. 6(A), the ring-shaped frame F supporting the wafer 11 through the spreading tape T is placed on the placement surface 26a of the frame holding member 26 and fixed to the frame holding member by clamps 28 26. At this time, the frame holding member 26 sets the position of the placement surface 26a to a reference position that is approximately the same height as the upper end of the expansion drum 22.

Next, the air cylinder 30 is driven to lower the frame holding member 26 to the expanded position as shown in FIG. 6(B). As a result, the ring-shaped frame F fixed to the mounting surface 26a of the frame holding member 26 also descends, and the spreading tape T attached to the ring-shaped frame F abuts on the upper edge of the expansion roller 22 and is mainly expanded In the radial direction.

As a result, radial tension acts on the wafer 11 adhered to the spreading tape T. In this way, when a radial tension is applied to the wafer 11, the wafer 11 is broken with the modified layer 21 as a breaking point, and is divided into element wafers 23 one by one.

In the method of manufacturing the element wafer of this embodiment, regarding the planned division lines 13a on the sides where the elements must be closely arranged, two modified layers 21 are formed at the same height along each planned division line 13a, and the wafer 11 A plurality of modified layers 21 are formed in the thickness direction.

Furthermore, compared to the pair of modified layers 21 on the side closest to the surface 11a of the wafer 11, the pair of modified layers 21 on the back side is formed on the side closer to the element 15, as shown in FIG. 6(B) The enlarged view of part A of is shown in FIG. 6(C). The side surface of the element wafer 23 obtained after the wafer 11 is divided is obliquely inclined from the surface where the element 15 is formed toward the center of the wafer. Furthermore, the dicing path 25 remains between adjacent element wafers 23.

Particularly not shown, regarding the planned dividing line 13b orthogonal to the planned dividing line 13a elongated in the first direction, as shown in FIG. 4, a modified layer is formed at a substantially central portion of the planned dividing line 13b For the reason of 21, when the dividing step shown in FIG. 6 is performed, the side surface of each element wafer 23 is perpendicular to the elements 15 formed on the surface.

According to the method of manufacturing the element wafer of the above-mentioned embodiment, it is necessary to closely arrange the side of the element because the side of the wafer is inclined obliquely from the surface to the center of the wafer. Therefore, a plurality of element wafers 23 are connected, for example, When the line sensor 27 is configured as shown in FIG. 7, the adjacent elements 15 can be arranged so that the element wafers 23 can be neatly arranged with almost no gaps.

In the above-mentioned embodiments, the device wafer of the present invention is applied to a semiconductor wafer to manufacture imaging devices such as CCD and CMOS. The example of the wafer has been described, but the manufacturing method of the present invention is not limited to this, and it is also applicable to the method of manufacturing an LED chip by dividing an optical element wafer with a plurality of LEDs formed on the surface.

10‧‧‧Chuck bed

11‧‧‧Semiconductor Wafer

11a‧‧‧surface

11b‧‧‧The back side of semiconductor wafer 11

13a‧‧‧Preparation line (cutting path)

14‧‧‧Concentrator

15‧‧‧Component

21‧‧‧Modified layer

P‧‧‧Spotlight

T‧‧‧Extended Tape

Claims (1)

A method for manufacturing an element wafer is to manufacture an element wafer from forming an element wafer in each area of the surface divided by a plurality of predetermined dividing lines having a predetermined width that intersect each other; , Including: a holding step, which is to hold the element wafer by making the surface side of the element wafer face the holding surface of the chuck bed; and the reforming layer forming step, after the holding step is carried out, relative to the element wafer The condensing point of the laser beam with the transparent wavelength is to the inside of the element wafer, and the laser beam is irradiated from the back of the element wafer along the two edges in the width direction of the planned dividing line, in the vertical direction Forming a plurality of layers of two modified layers that are parallel to each other; and a dividing step. After the modified layer forming step is performed, an external force is applied to the device wafer, and the device wafer is divided using the modified layer as a breaking point In the modified layer forming step, the modified layer on the back side is formed to a position that is more offset from the modified layer on the front side to the device side, and the modified layer on the back side is formed with a plurality of The modified layer on the back side includes a modified layer that overlaps in the vertical direction; the modified layer formed next to the modified layer on the surface side is formed with the modified layer on the surface side Overlapping in the thickness direction of the device wafer; the side surface of the device wafer broken along the plurality of modified layers is the most protruding surface side.

Images