TWI710014B - Saw wafer method - Google Patents

Abstract

A method of dicing wafers, especially refers to a method that can improve the DAG (Dice After Gind) or DBG (Dice Before Gind) process, and the technology of the present invention can improve the multiple advantages of product accuracy and high output efficiency.

Description

Saw wafer method

The present invention relates to a wafer dicing method, in particular to a method that can improve the DAG (Dice After Gind) or DBG (Dice Before Gind) process, and the technology of the present invention can improve the multiple advantages of product accuracy and high output efficiency.

In the application of the Internet of Things, such as the demand for "smaller, thinner, faster and higher performance" of wearable devices, common wearable devices such as smart bracelets and smart mobile devices have become common devices in daily life .

The manufacture of integrated circuits is based on silicon wafers that go through well-known processes such as yellow light process, etching process, thin film process and diffusion process. Finally, the function of integrated circuit will provide related products for wafer cutting, packaging and testing. Demand function.

Fig. 1 is plasma grinding and dicing (hereinafter referred to as DAG process, Dice After Gind). Simply put, the wafer is first attached with a grinding tape and then the wafer is polished to reduce its thickness to flatten the surface, and finally dicing.

Figure 2 is plasma cutting before polishing (hereinafter referred to as DBG process, Dice Before Gind), its purpose is to improve the shortcomings of the DAG process, reduce cracking on the back side and improve the flexural strength of the wafer, in addition, because it is divided to form crystals after the polishing is completed Therefore, it is expected to reduce the risk of chip breakage when processing thin wafers. At present, DAF (Die Attach Film) is mostly used in the DBG process, and it may also be comprehensive in the packaging and manufacturing of thin wafer stacks such as SiP (System in Package). Adopt DBG system Cheng. The DBG process plus DAF laser dicing process mainly first half-cut through the diced wafer, and attach a polishing tape for back polishing to polish the wafer flat.

As shown in Table 1, the sites and corresponding equipment required for DAG process and DBG process manufacturing are:

The advantages of using the DAG process to obtain products are: 1. Low price, 2. High popularity, 3. Fewer sites and 4. High output efficiency; But the DAG process is lacking in: 1. Cannot effectively improve the cracking problem, 2. .Poor accuracy of Z axis when cutting.

The advantages of using the DBG process to obtain products are: 1. Accurate work accuracy of the down-cut Z-axis, 2. Effectively improve front cracking and back cracking; but the DBG process lacks: 1. Low output efficiency, 2. Low popularity, 3. The equipment is expensive, 4. Compared with the DAG process, there are more additional maintenance costs for the lower site, 5. The consumable materials are expensive (for example: laser head).

From the above, it can be known that there is still room for improvement in DAG process or DBG process technology. After years of research, the inventor of this case finally developed the method of cutting wafers in this case.

The main purpose of the present invention is to provide a wafer dicing method that improves the shortcomings of the above-mentioned DAG process and the DBG process, and has both high Z-axis accuracy and the effects of improving front cracking and back cracking.

The manufacturing methods that can achieve the above objectives include: Step 1: Half-cut through the wafer; Step 2: Place the polishing tape on the wafer; Step 3: Perform back grinding of the wafer; Step 4: Cut DAF tape placement; Step 5: Peel off the surface protection tape; Step 6: Cut the wafer through the cutting equipment.

In step 1 of the present invention, a cutting device (model DFD6361) of DISCO is used to perform wafer half-cut through cutting.

In step 2 of the present invention, a fully automatic polishing tape laminating machine (model RAD-3510F/12) from LINTEC Advanced Technology is used to attach the polishing tape to the wafer.

In step 3 of the present invention, a disco company's grinding equipment (model DGP8761) is used to perform wafer back grinding.

In steps 4 and 5 of the present invention, the disco company's grinding equipment (model DFM2800) is used to perform DAF mounting, cutting frame sticking device, and surface protective film peeling device integrated device.

In step 6 of the present invention, the disco company's cutting equipment (model DFD6361) is used to perform overall wafer cutting.

In the embodiment of the present invention, the thickness of the half-through cutting is one-half to one-third the thickness of the wafer.

Accordingly, the process of the present invention has the following advantages:

1. The equipment used in the present invention is almost the same as the DAG process or the DBG process, so it is highly replaceable and common.

2. As shown in Table 2, the price of wafers manufactured by the present invention is competitive.

3. Equipped with DBG process to cut down the Z axis with high accuracy, effectively improving front cracking and back cracking.

4. High output efficiency increases the profits of the industry.

Figure 1 is a schematic diagram of the DAG process.

Figure 2 is a schematic diagram of the DBG process.

Figure 3 is a schematic diagram of the manufacturing process of the present invention.

Fig. 4 is a yield analysis of the present invention compared with conventional technologies.

Please refer to Figures 3, 4 and Table 2. The wafer dicing method of the present invention is used in the dicing of integrated circuits (die). The steps include:

Step 1: Half-cut through the wafer; Step 1 uses DISCO's cutting equipment (model DFD6361) to perform the half-cut through the wafer, and the thickness of the half-through cut is half or three of the wafer One part of the thickness.

Step 2: Place the polishing tape on the wafer; Step 2 is to use the automatic polishing tape laminator (model RAD-3510F/12) of LINTEC Advanced Technology to attach the polishing tape to the wafer .

Step 3: Perform wafer back grinding; Step 3 uses disco company's grinding equipment (model DGP8761) to perform wafer back grinding.

Step 4: Cut the DAF tape for placement.

Step 5: Peel off the surface protective tape; Steps 4 and 5 use the disco company's grinding equipment (model DFM2800) for DAF placement, cutting frame pasting device, and surface protective film peeling device integration device, which combines steps 4 and 5 It can be done in one stop.

Step 6: Fully cut the wafer through the cutting equipment; use the disco company's cutting equipment (model DFD6361) to cut the whole wafer.

Accordingly, the process of the present invention has the following advantages:

1. The equipment used in the present invention is almost the same as the DAG process or the DBG process, so it is highly replaceable and common.

2. As shown in Table 2, the price of the wafer manufactured by the present invention is competitive.

3. The process of the present invention has a DBG process with high precision of the Z-axis undercutting, which can effectively improve front cracking and back cracking.

4. High output efficiency increases the profits of the industry.

5. As shown in Figure 4, the product yield rate of the DAG process is about 20%; the product yield rate of the DBG process is about 99%; and through the manufacturing steps of the present invention, the product yield rate is 97.9%, which can be understood The price of constructing a production line can be lowered, but it can maintain the product yield and reduce costs, so that the profits of the industry can be greatly increased.

In summary, the structure of the present invention has never been seen in books and periodicals or used publicly, and sincerely meets the requirements of an invention patent application. I sincerely ask Jun Bureau to approve the patent as soon as possible.

Claims (1)

A method for dicing wafers includes: Step 1: Half-cut through the wafer, the aforementioned half-through cut thickness is one-half to one-third of the thickness of the wafer; Step 2: Place the polishing tape on the wafer ; Step 3: Grind the back of the wafer; Step 4: Die DAF tape placement; Step 5: Peel off the surface protection tape; Step 6: Cut the wafer through the dicing equipment.

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