KR20080114036A - Method for singulation of semiconductor chip - Google Patents

Abstract

The method of separating the semiconductor chip is provided to prevent the damage of wafer caused by the physical impact when transferring the wafer which is progressed by the grinding process and has a thin thickness. The method of separating the semiconductor chip comprises as follows. A step is for manufacturing the semiconductor chip(100) including the circuit part in the upper side of the wafer(10). A step is for making the wafer of thin thickness by grinding the lower surface of the wafer. A step is for attaching the wafer to faces the adhesive film for the die attach to the upper side of the carrier(110). A step is for cutting the wafer along the cutting line of the wafer to include the adhesive film for the die attach formed between the semiconductor chips. A step is for separating the semiconductor chip from the carrier in the cut wafer.

Description

Method for singulation of semiconductor chip

FIG. 1A is an exploded perspective view for attaching a wafer ground to a carrier in the present invention, and FIG. 1B is a cross-sectional view taken along line II ′ of FIG. 1A after attaching the wafer to the carrier.

Fig. 2A is a perspective view showing a state of cutting a wafer attached to a carrier according to the present invention, and Fig. 2B is a cross-sectional view of Fig. 2A taken along line II-II '.

3 is a cross-sectional view showing a state in which a semiconductor chip is separated from a carrier and individualized.

The present invention relates to a method for individualizing a semiconductor chip. More specifically, the present invention relates to a method of individualizing a semiconductor chip which prevents the wafer from being damaged during the subsequent process of individualizing the semiconductor chip from the wafer thinned by grinding.

In the semiconductor industry, a semiconductor package generally refers to a form in which a semiconductor chip, in which a microcircuit is designed, is sealed with a mold resin or ceramic so as to be protected from an external environment and mounted on an electronic device. In recent years, semiconductor chips are packaged for the purpose of improving the performance and quality of electronic devices through miniaturization, thinning, and multifunctionality of electronic devices, rather than packaging semiconductor chips for the purpose of enclosing, protecting, or simply mounting electronic devices. Doing. Therefore, the importance of semiconductor packages is increasing, and a wide variety of semiconductor packages have been developed.

Recently, as the thickness of semiconductor devices becomes thinner, the thickness of semiconductor chips embedded in semiconductor devices needs to be processed thinner. A general process proceeded to make the thickness of the semiconductor chip thin is a grinding process in which the back surface of the wafer on which the semiconductor chips are manufactured is polished and removed to a certain thickness.

However, in the related art, since the thickness of the ground wafer is thin, the process of shifting the wafer from the wafer to the process of individualizing the semiconductor chip, or attaching an adhesive to the back surface of the wafer for attaching the semiconductor chip to the member on which the semiconductor chip is mounted, and the wafer There is a problem that handling is difficult when proceeding with a cutting process for individualizing the semiconductor chip by cutting.

In addition, there is a problem that the wafer is easily cracked or a large amount of defects are generated in the cracked semiconductor chip even when the impact is applied to the wafer during the aforementioned process.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for individualizing a semiconductor chip which facilitates handling of the ground wafer and prevents cracking in the wafer in a subsequent process of the grinding process.

Such a method of individualizing a semiconductor chip for realizing the object of the present invention comprises the steps of manufacturing a plurality of semiconductor chips including a circuit portion on the upper surface of the wafer; Grinding the lower surface of the wafer opposite the upper surface of the wafer to reduce the thickness of the wafer; Attaching the wafer to the upper surface of the carrier to which the base adhesive film and the die attach adhesive film are sequentially attached so that the lower surface of the wafer faces the die attach adhesive film; Cutting the wafer to include an adhesive film for the die appetite along a cutting line of the wafer formed between the semiconductor chips; Separating the semiconductor chips from the carrier in the cut wafer.

Hereinafter, an individualization method of a semiconductor chip according to exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1A is an exploded perspective view for attaching a wafer ground to a carrier in the present invention, and FIG. 1B is a cross-sectional view taken along line II ′ of FIG. 1A after attaching the wafer to the carrier.

Before describing the semiconductor chip individualization method according to the present invention, a wafer and a semiconductor chip manufactured on the wafer will be described in brief.

As illustrated in FIG. 1A, the semiconductor chips 100 are manufactured in a plurality of columns and a plurality of rows on the circular wafer 10, and the semiconductor chips 100 are separated from each other by the cutting lines 12.

Although not shown in the drawing, circuit elements are formed in each semiconductor chip 100 to be connected to electrical elements and electrical elements that process information by an externally input electrical signal, and to transfer electrical signals to each of the electrical elements. do.

In addition, bonding pads 102 electrically connected to circuit wirings are arranged on the upper surface of each semiconductor chip 100.

The thickness from the lower surface of the wafer 10 in which the semiconductor chips 100 are not formed to the portion where the circuit wiring of the semiconductor chip 100 starts to be formed is thick. Therefore, when the semiconductor chip 100 is individualized by cutting the wafer 10 along the cutting line 12 separating the semiconductor chips 100, the thickness of the semiconductor chip 100 becomes thicker.

In order to improve this, when the semiconductor chips 100 are manufactured on the wafer 10, in general, the bottom surface of the wafer 10 from the bottom surface of the wafer 10 to the range where the circuit wirings of the semiconductor chip 100 are not damaged. Grinding is carried out to remove the grinding.

The thickness of the wafer 10 in which the grinding process is performed is reduced by about 50% compared to the thickness of the wafer 10 in which the grinding process is not performed. However, as the thickness of the wafer 10 decreases due to the grinding process, the handling of the wafer 10 becomes difficult when the subsequent process proceeds, and cracks are easily generated even in a weak impact.

In order to solve this problem, as shown in FIG. 1A, a carrier 110 for fixing the ground wafer 10 that is larger than the diameter of the wafer and capable of passing light, that is, ultraviolet light, is manufactured.

After cutting the wafer 10 in the center of the upper surface of the carrier 110, the base adhesive film 120 for easy separation of the semiconductor chips from the carrier 110, and the semiconductor chip 100 and the packaging individualized in the packaging process are provided. The die attach adhesive film 130 for attaching the members (not shown) to each other is sequentially attached.

Preferably, the base adhesive film 120 and the die attach adhesive film 130 are the same as the diameter of the wafer 10, and the base adhesive film 120 is an ultraviolet reaction film that weakens adhesion when reacted with ultraviolet light. In addition, the die attach adhesive film 130 is WBL.

When the base and the die attach adhesive films 120 and 130 are adhered to the upper surface of the carrier 110 in order, the wafer 10 is disposed so that the bottom surface of the ground wafer 10 faces the die attach adhesive film 130. ) Is attached to the top surface of the die attach adhesive film 130.

As such, the die attach adhesive film 130 is attached onto the carrier 110 without directly attaching the die attach adhesive film 130 to the rear surface of the wafer 10 thinned by the grinding process, and then ground. When the wafer 10 is attached to the upper surface of the die attach adhesive film 130, there is little physical impact applied to the wafer 10 in the process of attaching the wafer 10 and the die attach adhesive film 130. Therefore, cracks may be prevented from occurring in the thin wafer 10 during the process.

Fig. 2A is a perspective view showing a state of cutting a wafer attached to a carrier according to the present invention, and Fig. 2B is a cross-sectional view of Fig. 2A taken along line II-II '.

Referring to FIGS. 2A and 2B, after fixing the carrier 110 to which the wafer 10 is attached, along the cutting line 12 that separates the semiconductor chips 100 using the blade 200 rotating at a high speed. The wafer 10 is cut off.

At this time, the depth of the blade 200 is cut from the upper surface of the wafer 10, the cutting line 12 is shown as shown in Figure 2b to the interface between the die attach adhesive film 130 and the base adhesive film 120 to be. Most preferably, the blade slightly cuts the base film 120 past the interface between the die attach adhesive film 130 and the base adhesive film 120. The reason for slightly cutting the base film 120 is to completely remove the adhesive film 130 for die attach together with the semiconductor chip 100 in a subsequent process, that is, the process of separating the semiconductor chip 100 and the carrier 110. For that.

When the wafer 10 is transferred and the wafer 10 is cut while the ground wafer 10 is attached to the thick carrier 110, the carrier 110 causes the wafer 10 to be cut. Handling is easy and damage to the wafer 10 during the process can be minimized. Here, in the process of cutting the wafer 10, even if there is a physical impact from the blind 200 to the wafer 10, the die attach adhesive film 130, the base film 120, the carrier 130, and the like may be used as the wafer ( Since the shock applied to 10 is absorbed and dispersed, it is possible to minimize the occurrence of cracks in the wafer 10.

3 is a diagram showing a state in which a semiconductor chip is separated from a carrier and individualized.

When the wafer 10 is cut along the cutting line, ultraviolet light is irradiated from the lower surface of the carrier 110 as shown in FIG. 3. Then, since the carrier 110 is formed of a material that passes ultraviolet rays, ultraviolet light passes through the carrier 110 to reach the base adhesive film 120. The ultraviolet light reaching the base adhesive film 120 reacts with the base adhesive film 120 to weaken the adhesive force of the base adhesive film 120.

When the adhesion of the base adhesive film 120 is weakened by irradiation of ultraviolet light as described above, the pickup device 300 for picking up the semiconductor chips 100 separated from each other by vacuum pressure is lowered to the upper surface of the cut wafer 10. . Then, the semiconductor chip 100 located in the portion corresponding to the pickup device 300 among the semiconductor chips 100 separated from each other along the cut line 12a is adsorbed to the pickup device 300 by vacuum pressure. . Thereafter, when the pickup device 300 is raised, the semiconductor chip 100 adsorbed to the pickup device 300 is adhered to the carrier 110 and the base as shown in FIG. 3 due to the weakening of the adhesive force of the base adhesive film 120. Separated from the film 120, the semiconductor chip 100 is individualized. At this time, the die attach adhesive film 130 is attached to the lower surface of the semiconductor chip 100.

The semiconductor chips 100 individualized through the above process are attached to the mounting member through the adhesive film 130 for die attach, and then electrically connecting the semiconductor chip 100 and the mounting member to each other, the semiconductor chip 100. It is packaged through a molding process or the like to protect it from the external environment.

Hereinbefore, the present invention has been illustrated and described with reference to specific embodiments, but the present invention is not limited thereto, and the scope of the following claims is not limited to the spirit and scope of the present invention. It will be readily apparent to those skilled in the art that various modifications and variations can be made.

As described in detail above, when the wafer, which has been thinned by the grinding process, is attached onto the carrier with the die attach adhesive film as described above, and then subjected to individualization process, when the wafer is transferred, the die attach adhesive film And damage to the wafer due to physical impact in the step of attaching the wafer, the step of cutting the wafer, and the like.

Claims (5)

Manufacturing a plurality of semiconductor chips including a circuit portion on an upper surface of the wafer; Grinding the lower surface of the wafer opposite the upper surface of the wafer to reduce the thickness of the wafer; Attaching the wafer to the upper surface of the carrier to which the base adhesive film and the die attach adhesive film are sequentially attached so that the lower surface of the wafer faces the die attach adhesive film; Cutting the wafer to include an adhesive film for the die appetite along a cutting line of the wafer formed between the semiconductor chips;  Separating the semiconductor chips from the carrier in the cut wafer. The method of claim 1, wherein the carrier is formed of a material that transmits light. The method of claim 2, wherein the carrier is formed of any one material selected from glass and polymer. The method of claim 1, wherein the base adhesive film is an ultraviolet reaction film that does not have weak adhesion when reacted with ultraviolet light. The method of claim 4, wherein the semiconductor chip and the carrier are separated from each other by irradiating ultraviolet rays to the lower surface of the carrier.

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