JP4560391B2 - Method for manufacturing liquid discharge head - Google Patents

Description

The present invention relates to a manufacturing method of the liquid discharge head.

  In general, various semiconductor elements are manufactured through processes such as forming a plurality of elements on a wafer at the same time, separating them into individual semiconductor elements in a dicing process, and enclosing the package.

  As shown in FIG. 6A, in a general dicing process, the wafer 101 is mounted on an adhesive dicing tape 110, and the wafer is rotated by a rotating dicing blade B as shown in FIG. 6B. Cutting / separation is performed along a cutting line 101 (dicing street). In the case where individual elements are completely cut and separated by dicing, the tip of the dicing blade B is processed by cutting several tens of μm into the dicing tape 110. For this reason, at the time of dicing, the cutting waste generated from the wafer 101 and the cutting waste including the film base material and the adhesive of the dicing tape 110 are simultaneously scattered by the rotational force of the dicing blade, and these adhere to the surface of the wafer 101 being cut. .

  Further, the adhesive surface of the dicing tape 110 is exposed in the empty area 110 a of the dicing tape 110 between the frame K that supports the outer peripheral portion of the dicing tape 110 and the outer edge of the wafer 101. Normally, the processing area of the dicing blade B in dicing is set to be several millimeters to tens of millimeters larger than the wafer size, and the dicing blade B moves to the next cutting line after the outer periphery of the dicing blade B completely passes the outer peripheral edge of the wafer 101. Therefore, the dicing blade B directly cuts the dicing tape 110 in the empty area 110 a of the dicing tape 110. Similarly, the empty area 110a is cut at the beginning of dicing. For this reason, fine cutting waste mixed with the adhesive is also generated from the empty area 110 a of the dicing tape 110 without the wafer 101 and adheres to the surface of the wafer 101.

  In order to avoid such undesired deposits, it has been proposed to perform a process for reducing the adhesive strength of the dicing tape in the area where the dicing blade cuts along the cutting line. For example, when an ultraviolet curable adhesive tape is used as the dicing tape, a method of selectively curing the dicing tape adhesive on the wafer cutting line as disclosed in Patent Document 1, or Patent Document 2 As disclosed, there is a method in which the adhesive on the entire surface of the empty area of the dicing tape between the frame and the wafer is cured in advance.

In addition, a combination of the above two methods is also conceivable in which the adhesive of the dicing tape in all the areas where the dicing blade may touch is cured in advance.
JP-A-62-79649 JP 2002-299295 A

  However, the adhesive in the empty area of the dicing tape has an effect of preventing the generated cutting waste from adhering and holding it and reattaching it to the wafer surface. Further, it is not preferable to cure even a portion of the adhesive that is not likely to be touched by the dicing blade.

  That is, considering that the pressure-sensitive adhesive prevents chip fly during dicing, it is preferable that the area where the pressure-sensitive adhesive of the dicing tape is cured in advance is as small as possible.

  On the other hand, in the method disclosed in Patent Document 1, the cutting line set on the wafer is used in the method in which the adhesive of the dicing tape is partially exposed through the light shielding mask and cured along the cutting line of the wafer. There is a slight shift in the alignment between the three patterns: the pattern opening, which is a translucent part of the light shielding mask, and the actual cutting line by the scanning of the dicing blade. In general, the positional deviation between the cutting line on the wafer that is directly aligned on the dicing machine and the actual cutting line by the dicing blade is almost negligible. Relatively large. This is because there is no target on the back surface of the wafer that serves as a reference for alignment of the light shielding mask.

  The positional deviation of the light shielding mask is determined by the magnitude of the positional deviation between the vertical and horizontal directions and the three axes of inclination. In particular, the positional shift due to the inclination of the light shielding mask leads to a risk that the dicing blade deviates from the range where the adhesive is previously cured in a line shape and cuts the uncured adhesive.

The present invention has been made in view of the unsolved problems of the prior art, it prevents the dicing tape of shavings having tackiness occurs, the manufacture higher-quality liquid discharge head it is an object to provide a method for manufacturing a liquid discharge head capable.

In order to achieve the above object, a method for manufacturing a liquid discharge head according to the present invention includes a mounting step of attaching a back surface of a wafer in which a plurality of discharge elements having discharge means are arranged on the surface to an ultraviolet curable adhesive of a dicing tape, and the curing unit wafer is a line-shaped portion corresponding to the cutting line for cutting the wafer of the adhesive in the wafer area, the wafer region said cutting lines of said adhesive outside the wafer area The wafer outer cured portion is a line-shaped portion corresponding to both extended portions extending in one direction from the inside to the outside of the wafer region and in the opposite direction, and the line width of the wafer outer cured portion is the wafer width. Ri greater than Na linewidth of the inner hardened part, ultraviolet so that the such adhesive unhardened part outside the wafer area, the pressure-sensitive adhesive from the back side of the wafer through the mask A step of forming by causing radiation to partially cure the adhesive and reduce the adhesive strength of the wafer outer hardened portion and the wafer in the cured part, along the cutting line and the extended portion, the And a separation step of separating the plurality of ejection elements in this order by dicing the wafer and the dicing tape with a dicing blade from the front side of the wafer.

Line dicing line shaped region of the tape adhesive to reduce the pre-adhesive force before dicing, even if there is a positional deviation of the inclination direction with respect to the cutting line by a dicing blade, which reduces the adhesive strength of the dicing tape It is possible to avoid the risk that the dicing blade cuts off the portion that has deviated from the shape portion and maintained the adhesive force. As a result, it is possible to prevent the attachment of cutting waste due to dicing and to manufacture a highly reliable liquid discharge head .

  For example, when the semiconductor element separated by dicing is an ejection element of a liquid ejection head having an orifice on the surface, there is no change in the ejection direction due to the remaining residue of cutting chips around the orifice, and stable ejection of droplets Therefore, it is possible to realize a printer with high image quality.

As shown in FIG. 1, prior to dicing to separate the semiconductor elements 1 a of the wafer 1 , the back surface of the wafer 1 is affixed to the adhesive of the dicing tape 10 , and the wafer 1 cutting line 1 b and the outer edge of the wafer 1 are crossed. Then, the adhesive at the line-shaped portion of the dicing tape 10 corresponding to the extension of the cutting line 1b extending to the empty area 10a of the dicing tape 10 outside the wafer is cured to selectively reduce the adhesive force.

Of the line-shaped portions of the dicing tape 10 that is selectively cured in this way, as shown in FIG. 2A, the inside of the wafer that is a line-shaped portion corresponding to the cutting line 1b of the wafer 1 By configuring the line width W ₂ of the outside-wafer cured portion 10c, which is a line-shaped portion extending to the empty area 10a, to be larger than the line width W ₁ of the cured portion 10b, (b of FIG. ), Even when the notch 1c by the dicing blade is inclined with respect to the cured portions 10b and 10c of the dicing tape 10, the dicing blade is not cut into the uncured adhesive as shown in FIG. To avoid.

  The dicing tape 10 may be an ultraviolet curable adhesive tape or a heat curable adhesive tape.

  Further, as shown in FIG. 1 (b), in the in-wafer cured portion 10b of the dicing tape 10, the dicing blade is uncured if the area located on the outer peripheral portion of the wafer is set to the same width as the outside wafer cured portion 10c. It is possible to more reliably prevent cutting into the adhesive.

  As shown in FIG. 3, in order to separate the semiconductor element 1a of the wafer 1 along the cutting lines 1b in the X and Y directions, first, as shown in FIG. The wafer 1 is mounted on a dicing tape 10 that is an adhesive tape, and the adhesive of the dicing tape 10 on the cutting line 1b and the cutting line 1b extending to the empty area 10a of the dicing tape 10 as shown in FIG. The adhesive on the extension line is cured by exposure through the light shielding mask M in advance.

That is, as shown in FIG. 3A, the wafer 1 is tape-mounted, and as shown in FIG. 3B, the ultraviolet ray P ₁ is irradiated through the light shielding mask M and overlaps the pattern opening M ₁ of the light shielding mask M. The adhesive of the dicing tape 10 is cured, diced by the dicing blade B as shown in (c), and the adhesive of the dicing tape 10 is cured over the entire surface by irradiating ultraviolet rays P ₂ as shown in (d). The separated element 1a is picked up as shown in FIG.

FIG. 4 illustrates the light shielding mask M used in the curing process of the dicing tape 10. As shown in FIG. 4A, the pattern opening along the cutting line 1 b of the wafer 1 and its extension line is formed over the entire surface of the light shielding mask M. M ₁ and an opening M ₂ for alignment are provided. Alternatively, as shown in FIG. 4B, a mask having a pattern opening M ₁ up to a region where the outer periphery of the wafer 1 is oversized by about 5 mm may be used.

As shown in FIG. 2A, in the curing process of the dicing tape 10, the cutting line 1b of the wafer 1 and the cured parts 10b and 10c of the dicing tape 10 are often displaced in the tilt direction (θ direction). Therefore, the line width W ₂ of the outside wafer cured portion 10 c in the empty area 10 a of the dicing tape 10 is larger than the line width W ₁ of the in-wafer cured portion 10 b on the cutting line 1 b of the wafer _1. And That is, the opening width of the pattern opening M ₁ of the light shielding mask M is set to the outside of the wafer outer position (see FIG. 1A) or slightly from the inner side to the outer side of the wafer outer position (see FIG. 1B). The line width W ₁ along the cutting line 1b at the center of the wafer is made larger.

In this embodiment, the blade thickness used during dicing is about 80 μm, and as shown in FIG. 2B, a cut 1c along the cutting line 1b having a width of about 80 μm is formed in the wafer 1 after dicing. Further, the line width W ₁ of the in-wafer cured portion 10b which is the cured portion of the adhesive on the cutting line 1b is about 140 to 150 μm, and the line width W ₂ of the outside-wafer cured portion 10c on the extension of the cutting line 1b is about The pattern opening M ₁ of the light shielding mask M is set so as to be 240 to 250 μm.

  Since the adhesives of the hardened portions 10b and 10c reduce or lose the adhesive force by exposure to ultraviolet rays, most of the cutting waste generated when the dicing blade B cuts the adhesives of the hardened portions 10b and 10c Does not reattach to the surface with 1a. Moreover, even if there is something that reattaches, it can be easily removed in the washing step after dicing.

  On the other hand, as shown in FIG. 2C, a positional shift occurs in the alignment between the light shielding mask M and the wafer 1, and the dicing tape 10 is positioned at a position shifted in the θ direction from the cutting line 1b of the wafer 1. When the hardened portions 10b and 10c are formed with substantially the same line width, the cut 1c due to the scanning of the dicing blade B deviates from the hardened portion 10c outside the wafer, particularly in the empty area 10a farthest from the center of the wafer 1. Thus, the uncured region of the adhesive is cut.

  Therefore, in this embodiment, as shown in FIG. 2B, the notch 1c by the dicing blade B is formed in the outside-curing portion by forming the outside-wafer curing portion 10c wider than the in-wafer curing portion 10b. Prevent the danger of deviating from 10c.

  The line width of the in-wafer cured portion 10b on the cutting line 1b of the wafer 1 may be about 240 to 250 μm, which is the same as the line width of the out-of-wafer cured portion 10c. Since the holding force of the element 1a on the dicing tape 10 is reduced, there is a risk of chip fly.

  According to the present embodiment, it is possible to avoid the risk that the dicing blade B cuts the uncured adhesive in the empty area 10a of the dicing tape 10 while maintaining the holding force of the element 1a.

  In order to further improve safety, in consideration of the fact that the farthest away from the wafer center, the notch by the scanning of the dicing blade deviates from the hardened portion and the risk of cutting the uncured area of the adhesive increases. As shown in (1), the line width of a part of the in-wafer cured portion 10b in the outer peripheral portion of the wafer 1 may be wide like the line width of the out-wafer cured portion 10c in the empty region 10a.

  It is also conceivable to gradually increase the line width of the hardened portion from the center of the wafer toward the empty area.

  When the light-shielding mask M shown in FIG. 4A is used, a wide outside-curing portion of the wafer can be provided in the entire empty area 10a of the dicing tape 10.

  FIG. 5 shows a liquid discharge head in which discharge elements 51 and 52 having discharge means are mounted on the element surface, similar to the semiconductor element 1a obtained by the dicing method of the present embodiment. After the side is bonded to the mount substrate 53, the liquid discharge head is configured through electrical connection with the flexible substrate 54, bonding with the ink tank 56 as the liquid supply means held by the tank holder 55, and the like. A recording apparatus (printer) equipped with this liquid discharge head can discharge droplets stably without causing droplet droplets. In addition, in the long-term use, it was possible to obtain excellent reliability with no orifice accumulation or ejection failure.

  In this example, an ultraviolet curable dicing tape was used. However, when a thermosetting dicing tape, for example, Ribata Alpha (type M) manufactured by Nitto Denko Corporation was used and heat rays were selectively irradiated. The same effect was obtained in.

  The present invention is not limited to the ejection elements of the liquid ejection head, and can be widely applied to dicing for cutting out semiconductor elements mounted on various semiconductor devices from a wafer.

It is a figure explaining the dicing tape processing process by one Example and its modification. It is a figure which compares the Example of FIG. 1 with a prior art example. FIG. 2 is a process diagram illustrating a wafer dicing method according to the embodiment of FIG. 1. It is a figure explaining a light-shielding mask. It is a figure explaining a liquid discharge head. It is a figure explaining a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wafer 1a Semiconductor element 1b Cutting line 1c Cutting 10 Dicing tape 10a Unoccupied area 10b Hardened part in wafer 10c Hardened part outside wafer

Claims (3)

A mounting step of attaching a back surface of a wafer in which a plurality of discharge elements having discharge means are arranged on the surface to an ultraviolet curable adhesive of a dicing tape;
An in-wafer cured portion that is a line-shaped portion corresponding to a cutting line for cutting the wafer among the adhesive in the wafer area, and the cutting line in the adhesive outside the wafer area The wafer outer cured portion is a line-shaped portion corresponding to both extended portions extending in one direction from the inside to the outside of the wafer region and in the opposite direction, and the line width of the wafer outer cured portion is the wafer width. Ri greater than Na linewidth of the inner hardened part, in so that the such adhesive unhardened part outside the wafer area, by irradiating ultraviolet rays to the adhesive from the back side of the wafer through the mask the Forming the adhesive by partially curing the adhesive and reducing the adhesive force between the in-wafer cured portion and the outside-cured portion ; and
A separation step of dicing the wafer and the dicing tape by a dicing blade from the surface side of the wafer along the cutting line and the extension portion to separate the plurality of ejection elements;
A method of manufacturing a liquid discharge head having the above in this order. In the forming step, according to claim 1, wherein the line width of the wafer in the curing unit for curing the adhesive, which gradually increases toward the outside of the wafer region from the wafer center of the pressure-sensitive adhesive Manufacturing method of the liquid discharge head. A mounting step of attaching a back surface of a wafer in which a plurality of discharge elements having discharge means are arranged on the surface to a heat ray curable adhesive of a dicing tape;
An in-wafer cured portion that is a line-shaped portion corresponding to a cutting line for cutting the wafer among the adhesive in the wafer area, and the cutting line in the adhesive outside the wafer area The wafer outer cured portion is a line-shaped portion corresponding to both extended portions extending in one direction from the inside to the outside of the wafer region and in the opposite direction, and the line width of the wafer outer cured portion is the wafer width. Ri greater than Na linewidth of the inner hardened part, in so that the such adhesive unhardened part outside the wafer area is irradiated with heat rays to the adhesive from the back side of the wafer through the mask the A forming step in which the adhesive is partially cured to reduce the adhesive strength of the in-wafer cured portion and the outside-cured portion of the wafer; and
A separation step of dicing the wafer and the dicing tape by a dicing blade from the surface side of the wafer along the cutting line and the extension portion to separate the plurality of ejection elements;
A method of manufacturing a liquid discharge head having the above in this order.

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