JP4843390B2 - Manufacturing method of semiconductor device - Google Patents

Description

  The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for manufacturing a semiconductor device in which a resin-sealed wafer level CSP or the like is formed by dicing.

  In the process of manufacturing a resin-sealed wafer level CSP or the like, there is a step of finally cutting (dicing) a semiconductor substrate in a wafer state into individual chips.

  In this process, for example, after a semiconductor wafer is diced into a strip shape with a dicing blade made of diamond or the like, it is generally diced in a direction perpendicular to the dicing direction, and finally the wafer is cut into a grid pattern. (See FIG. 8).

  However, since a semiconductor wafer having a generally circular shape is usually cut out into a substantially rectangular shape, a large number of end materials represented by a substantially triangular shape in which a chip region cannot be secured are generated on the outer periphery of the semiconductor wafer.

Here, since the circuit surface is sealed with resin at the time of wafer level CSP dicing, the processing load of dicing is large, and the end material (triangular chip) on the wafer outer peripheral portion tends to be scattered. If the end material is scattered during dicing, the dicing blade is damaged, causing frequent chipping and, in the worst case, causing blade breakage, which is a serious problem. In addition, the chip itself may be damaged.
At present, when the dicing blade is made thinner from the viewpoint of miniaturization of the wafer level CSP and cost reduction of the manufacturing cost, the problem is remarkably caused.

  Therefore, in the conventional wafer level CSP manufacturing method, an adhesive tape called a dicing tape is attached to the back surface of the semiconductor wafer so that the end material does not scatter during dicing, but the end material has a small area. Since sufficient adhesive strength cannot be secured, it has not yet been possible to eliminate damage to the blade due to scattering of the end material.

On the other hand, as a semiconductor device manufacturing method for manufacturing a wafer level CSP by dicing, it is described in Japanese Patent Application Laid-Open No. 2004-146487, and a method shown in FIG. 9 has been proposed.
This conventional example is a method of dicing so as not to generate the end material (triangular chip) on the outer peripheral portion of the wafer in order to eliminate damage to the blade due to scattering of the end material.
However, in the case of this method, complicated dicing must be performed by moving the dicing blade up and down, and there is a problem in that the manufacturing time is increased due to the complicated process.

JP 2004-146487 A

  The present invention has been made in view of the above circumstances, does not require a complicated dicing process, and troubles such as breakage of the dicing blade and chipping when the end material scatters when dicing the semiconductor wafer. Therefore, an object of the present invention is to provide a method for manufacturing a semiconductor device such as a wafer level CSP, which can prevent the scattering of the end material.

  The present invention solves the above-described problems by the solving means described below.

The method of manufacturing a semiconductor device according to the present invention, Oite the outer peripheral portion of the back surface of the semiconductor wafer, so as to pass through the position of the end material produced by dicing in a subsequent step, to form a linear groove along the circumference Thereafter, a dicing tape is attached to the back surface of the semiconductor wafer, an adhesive of the dicing tape is infiltrated into the groove portion, and the semiconductor wafer is diced by a dicing blade.

  Here, it is effective to form a plurality of linear grooves.

  Further, it is characterized in that, instead of the linear groove portion, the dotted groove portion is formed by intermittently gathering on the line along the circumference.

  Further, the linear groove portion and the dotted groove portion are formed by a laser marker.

  According to the first aspect, the adhesive force of the dicing tape is strengthened by the action of the linear groove portion along the circumference formed on the outer peripheral portion of the back surface of the semiconductor wafer. That is, when the adhesive of the dicing tape enters the linear groove, it acts like a nail or a wedge, and the force with which the dicing tape tries to adhere to the semiconductor wafer is strengthened. As a result, scattering of the end material can be prevented.

  According to claim 2, since a plurality of linear groove portions can be formed on the back surface of the dicing tape even if the end material has a minute size, the dicing tape Strength to stick to semiconductor wafers is strengthened. As a result, the effect of preventing scraps from scattering increases.

  According to the third aspect, instead of the linear groove portion, the point-like groove portion can be intermittently assembled on the line along the circumference to form the same as the effect caused by the linear groove portion. Since the force with which the dicing tape tries to adhere to the semiconductor wafer is strengthened, an effect of preventing the scattering of the end material occurs.

  According to the fourth aspect, by processing the linear groove portion and the dotted groove portion formed on the back surface of the semiconductor wafer with the laser marker, the desired groove portion can be formed easily and at low cost. Further, the depth and width of the groove can be easily controlled.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 and 2 are schematic views for explaining a manufacturing method according to the first embodiment of the present invention. FIG. 3 is a schematic view for explaining the dicing procedure and the location where the end material is generated in the manufacturing method according to the present invention. FIG. 4 is a schematic view showing a state of dicing and end material generation in the manufacturing method according to the first embodiment of the present invention.

As shown in FIG. 1, a linear groove portion 3 along the circumference is formed in the outer peripheral portion 2 on the back surface of the semiconductor wafer 1 to be diced.
The position where the linear groove portion 3 is formed is preferably formed as close to the outer peripheral edge 7 of the semiconductor wafer 1 as possible within the capability of the processing machine. By doing so, even if the end material 5 is a minute size, the groove portion 3 comes to the back surface thereof, and the anchor effect described later is exhibited.

The processing for forming the linear groove 3 is performed by a laser marker (not shown) as an example. By processing with a laser marker, a desired groove can be formed easily and at low cost. In addition, the effect of facilitating the control of the depth and width of the groove occurs.
In addition, the apparatus which processes the linear groove part 3 is not limited to a laser marker, You may be another mechanical process and a chemical process.

  The shape of the linear groove 3 is formed so that silicon on the back surface of the semiconductor wafer 1 is slightly dug. As an example, the groove portion 3 is formed to have a line width of 30 μm and a depth of about 2 to 3 μm using a laser having an output of 0.65 W.

  Subsequently, the dicing tape 10 is adhered to the back surface of the semiconductor wafer 1 on which the linear grooves 3 are formed. The size of the dicing tape 1 may be any size as long as the entire back surface of the semiconductor wafer 1 can be adhered.

The adhering power in the linear groove portion 3 is reinforced by the anchor effect generated in the linear groove portion 3 in the adhered dicing tape 10. That is, when the adhesive of the dicing tape 10 enters the linear groove portion 3, it acts like a nail or a wedge, and the force that the dicing tape 10 tries to adhere to the semiconductor wafer 1 is strengthened. .
In addition, as an example of the adhesive of the dicing tape 10, ultraviolet type paste is used. This glue has the property of being cured by irradiation with ultraviolet rays.

Thereafter, as shown in FIG. 3, the semiconductor wafer 1 is diced by the dicing blade 11. As a dicing procedure, first, dicing is performed linearly in the direction of the arrow on the dicing lines in the order of the dicing lines 12a, 12b, 12c, 12d, and 12e in FIG. Thereby, the semiconductor wafer 1 becomes a strip shape. The dicing blade 11 does not need to be moved up and down during dicing.
Subsequently, dicing is performed linearly on the dicing lines in the direction of the arrows in the order of the dicing lines 13a, 13b, 13c, 13d, and 13e. Thereby, the semiconductor wafer 1 is processed into chip-shaped semiconductor devices 6a to 6n.

  Here, in the case of the semiconductor device manufacturing method according to the conventional embodiment as shown in FIG. 7, only one surface of the bottom surface 53 is adhered to the dicing tape 54 in the case of the dicing blade. 55, the energy generated when dicing the semiconductor wafer 51 overcomes the adhesive force of the bottom surface 53 portion, and the end material 52 is scattered frequently. If it only scatters, it will not be a big problem, but if the scattered end material 52 hits the dicing blade mounting portion 56 and bounces off, and impacts the dicing blade 55, the dicing blade 55 will be cracked, distorted, or chipped. Cause trouble.

  However, when the semiconductor wafer 1 is diced with the dicing blade 11 as shown in FIG. 4 by carrying out the manufacturing method according to the present invention, the adhesive of the dicing tape 10 is applied to the linear grooves 3 of the end material 5. Since it penetrates and exhibits the anchor effect, it becomes possible to prevent the end material 5 from being scattered, and it has a great effect in preventing the trouble caused by the scattering.

  Therefore, it is preferable to form the linear groove 3 at a position as close to the outer peripheral edge 7 of the semiconductor wafer 1 as possible within the capability of the processing machine. By doing so, even if the end material 5 is a minute size, the groove portion 3 is formed on the back surface thereof, an anchor effect can be generated, and scattering of the end material during dicing is prevented. Because it becomes possible.

FIG. 5 shows an example of a manufacturing method according to the second embodiment of the present invention.
In the second embodiment of the present invention, a plurality of linear grooves 3 in the first embodiment are formed. As more linear grooves 3 are formed, the area where the anchor effect occurs is increased, so that the effect of preventing scattering of the end material can be increased.

  As an example, the structure which forms two linear groove parts like 3a and 3b in a figure can be considered. The grooves 3a and 3b are formed on a line along the circumference as an example. The processing for forming the linear grooves 3a and 3b is performed by a laser marker. However, it is preferable that the linear grooves 3a and 3b be formed as close to the outer peripheral edge 7 of the semiconductor wafer 1 as possible within the capability of the processing machine. By doing so, even if the end material 5 is a minute size, the groove portion 3 is formed on the back surface thereof, an anchor effect can be generated, and scattering of the end material during dicing is prevented. Because it becomes possible.

  In addition, it is preferable that the linear groove portions 3a and 3b be as close as possible to each other. By doing so, even if the end material 5 is a minute size, a plurality of grooves 3 can be formed on the back surface thereof. As a result, it is possible to increase the region where the anchor effect occurs, and to increase the effect of preventing the end material 5 from scattering.

FIG. 6 shows an example of the manufacturing method according to the third embodiment of the present invention.
In the third embodiment of the present invention, instead of the linear groove portion 3 in the first embodiment, the dotted groove portion 4 is intermittently formed on the outer peripheral portion 2 on the back surface of the semiconductor wafer 1 to be diced. It is formed by gathering together.

  As an example, the dotted groove 4 is formed on a line along the circumference. The processing for forming the spot-like groove 4 is performed by a laser marker, but it is preferable to form it at a position as close to the outer peripheral edge 7 of the semiconductor wafer 1 as possible within the capability of the processing machine. By doing so, even if the end material 5 is a minute size, the groove portion 4 is formed on the back surface thereof, an anchor effect can be generated, and scattering of the end material during dicing is prevented. Because it becomes possible.

  In addition, it is preferable that the adjacent groove portions 4 formed as a group are as narrow as possible. By doing so, even if the end material 5 is a small size, more dotted grooves 4 can be formed on the back surface thereof. As a result, it is possible to increase the region where the anchor effect occurs, and to increase the effect of preventing the end material 5 from scattering.

  With the semiconductor device manufacturing method according to the present invention, a semiconductor wafer is diced into strips and then diced in a right angle direction. It was possible to prevent and solve problems such as blade breakage.

It is the schematic for demonstrating the manufacturing method which concerns on 1st embodiment of this invention. It is the schematic for demonstrating the manufacturing method which concerns on 1st embodiment of this invention. It is the schematic for demonstrating the procedure of the dicing in the manufacturing method which concerns on this invention, and the generation | occurrence | production location of an end material. It is the schematic which shows the mode of the dicing and edge material generation | occurrence | production in the manufacturing method which concerns on 1st embodiment of this invention. It is the schematic for demonstrating the manufacturing method which concerns on 2nd embodiment of this invention. It is the schematic for demonstrating the manufacturing method which concerns on 3rd embodiment of this invention. It is the schematic for demonstrating the example of the manufacturing method which concerns on the conventional embodiment. It is the schematic which shows the dicing method of the general semiconductor wafer employ | adopted in the manufacturing method which concerns on the conventional embodiment, and the manufacturing method which concerns on embodiment of this invention. It is the schematic for demonstrating the other example of the manufacturing method which concerns on the conventional embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor wafer 2 Outer peripheral part of semiconductor wafer back surface 3 Linear groove part 4 Dotted groove part 5, 5a-5t End material 6a-6l Chip-shaped semiconductor device 7 Outer periphery 10 Dicing tape 11 Dicing blade 12 Dicing blade attachment part

Claims (4)

Oite the outer peripheral portion of the back surface of the semiconductor wafer, so as to pass through the position of the end material produced by dicing in a subsequent step, after forming the linear groove along the circumference,
A dicing tape is attached to the back surface of the semiconductor wafer, and the adhesive of the dicing tape is allowed to enter the groove,
A semiconductor device manufacturing method, wherein the semiconductor wafer is diced by a dicing blade. 2. The method of manufacturing a semiconductor device according to claim 1, wherein a plurality of the linear grooves are formed. 3. The method of manufacturing a semiconductor device according to claim 1, wherein the groove portions are formed by intermittently gathering on the line along the circumference instead of the linear groove portions. The method for manufacturing a semiconductor device according to claim 1, wherein the linear groove portion and the dotted groove portion are formed by a laser marker.