CN103545254B - Wafer laser processing - Google Patents

Abstract

The invention provides a wafer laser processing method, which comprises the following steps: providing a wafer; placing the wafer on a film mounter to carry out film bonding on the back of the wafer; The outer periphery is covered with a ring-shaped element, the inner edge of the ring-shaped element covers the outer edge of the wafer, and the bottom surface of the ring-shaped element is pasted with a film; the film-coated wafer and the ring-shaped element are positioned in the laser cutting equipment, and the laser is cut along the wafer. Cutting the cutting line of the wafer exposed outside the annular element by laser cutting; disassembling the annular element; removing the film on the back of the wafer; and plating metal on the back of the wafer. In the wafer laser processing method of the present invention, the outer edge of the wafer is covered by the annular element without being cut, so that the edge strength of the cut wafer is ensured in subsequent processing, On the whole, the integrity and operability strength of the wafer are guaranteed, and it is not easy to break, which greatly increases the yield rate of processing and reduces the fragmentation rate.

Description

Wafer laser processing method

technical field

The invention relates to a wafer laser processing method.

Background technique

With the continuous increase of market demand, the LED manufacturing industry has higher and higher requirements for production capacity, yield and luminous brightness. Laser processing technology has become the primary tool in the LED manufacturing industry and the industry standard for high-brightness LED wafer processing.

Laser scribing greatly reduces wafer microcracks and microcrack expansion, and greatly reduces the distance between LED monomers, which not only increases production capacity, but also increases production efficiency. The laser scribing mentioned here refers to laser cutting wafers.

At present, the production process of wafers has begun to turn to back-plating metal on wafers to achieve the purpose of improving brightness. However, after the back metallization, the scribing process cannot form scratches on the wafer, so the current production process is changed to scribing before the back metallization. However, when scribing, the laser is driven by the wafer The edge of the wafer cuts the wafer along dicing lines. In the subsequent process of removing the film on the back of the wafer, the edge of the wafer is easily broken due to the tearing force, affecting subsequent processing and failing to meet production requirements.

Contents of the invention

The purpose of the embodiments of the present invention is to provide a laser processing method for a wafer, aiming to solve the problem that the edge of the wafer is broken due to the tearing force in the traditional wafer processing process after dicing.

The embodiment of the present invention is achieved in this way, a wafer laser processing method, which includes the following steps:

A wafer is provided, the wafer has a front side and a back side with electrodes, the back side of the wafer is provided with dicing lines;

The wafer is placed on a film laminating machine to carry out the back film lamination of the wafer;

A ring-shaped element is set on the periphery of the wafer on the film mounter, the inner edge of the ring-shaped element covers the outer edge of the wafer, and the bottom surface of the ring-shaped element is pasted with a film;

The film-attached wafer and the annular element are positioned in a laser cutting device, and the laser light emitted by the laser cutting equipment is laser cut along the cutting line of the wafer exposed outside the annular element;

dismantling said ring element;

removing the backside film of the wafer;

Metallization is applied to the front side of the wafer.

In the wafer laser processing method of the present invention, the outer edge of the wafer is covered by the annular element without being cut, so that the edge strength of the cut wafer is ensured in subsequent processing, Overall, the integrity and operability strength of the wafer are guaranteed, and it is not easy to break, which greatly increases the processing yield and reduces the fragmentation rate.

Description of drawings

FIG. 1 is a schematic diagram of a ring-shaped element required for a wafer laser processing method provided by an embodiment of the present invention.

FIG. 2 is a schematic diagram of the use of ring elements in the wafer laser processing method provided by the embodiment of the present invention.

FIG. 3 is a schematic diagram of film removal of a wafer laser processing method provided by an embodiment of the present invention.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

Referring to FIGS. 1 to 3, the wafer laser processing method provided by the embodiment of the present invention includes the following steps:

Provide a wafer 10, the wafer 10 has a front 11 and a back 12 with electrodes (not shown), the back 12 of the wafer 10 is provided with a dicing line (not shown);

The wafer 10 is placed on a film mounter (not shown in the figure) to carry out film bonding on the back of the wafer 10, and the film to be pasted is a white film 30;

An annular element 20 is set on the periphery of the wafer 10 on the film mounter, the inner edge of the annular element 20 covers the outer edge of the wafer 10, and the bottom surface of the annular element 20 is pasted with a film;

Position the film-attached wafer 10 and ring-shaped element 20 in a laser cutting device, and the laser emitted by the laser cutting device performs laser along the cutting line of the wafer 10 exposed outside the ring-shaped element 20 cutting;

dismantling said annular element 20;

Removing the back film of the wafer 10, that is, removing the white film 30;

Plating metal on the front side of the wafer 10 .

In the wafer laser processing method of the present invention, the outer edge of the wafer 10 is covered by the annular element 20 without being cut, so that the cut wafer 10 can ensure the edge The strength ensures the integrity and operability of the wafer 10 as a whole, and it is not easy to break, which greatly increases the processing yield, reduces the fragmentation rate, reduces the difficulty of downstream LED processing, and improves product yield. Rate.

The ring element 20 covers the outer edge of the wafer 10 . The inner diameter of the annular element 20 is smaller than the outer diameter of the wafer 10. During the dicing process, due to the protection of the annular element 20, the periphery of the wafer 10 is not scratched by the laser, thereby The integrity of the wafer periphery is guaranteed. A scratch 13 is formed on the cut portion of the wafer 10 .

After the front side of the wafer 10 is metallized, it also includes the steps of sticking a film on the back side of the wafer 10 , splitting, flipping the film and expanding the film. The splitting is splitting the cut wafer 10 on a splitting machine. At this time, splitting is performed except for the cut part and the uncut part of the wafer 10 . The reverse film is to remove the film on the back side of the wafer 10 after the film is pasted on the front side of the wafer 10 . The expanding film is to increase the distance between the crystal grains formed after cutting the wafer 10 , so as to test each crystal grain, and during the testing process, the surrounding crystal grains will not be damaged.

Further, the annular element 20 is made of metal, such as iron.

Further, the thickness of the annular element 20 ranges from 0.4 mm to 0.7 mm. A stepped groove 21 for accommodating the outer edge of the wafer 10 is defined on the bottom surface of the inner edge of the annular element 20 . The depth of the step-shaped groove 21 in the thickness direction of the annular element 20 ranges from 0.1 mm to 0.4 mm. The width of the outer edge of the wafer 10 covered by the inner edge of the annular element 20 ranges from 0.2 mm to 1.5 mm.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (6)

1. A wafer laser processing method, comprising the steps of: A wafer is provided, the wafer has a front side and a back side with electrodes, the back side of the wafer is provided with dicing lines; The wafer is placed on a film laminating machine to carry out the back film lamination of the wafer; A ring-shaped element is set on the outer periphery of the wafer on the film mounter, the inner edge of the ring-shaped element covers the entire outer edge of the wafer, and the inner diameter of the ring-shaped element is smaller than the wafer. The outer diameter of the ring-shaped element is attached to the bottom surface of the film; The film-attached wafer and the annular element are positioned in a laser cutting device, and the laser light emitted by the laser cutting equipment is laser cut along the cutting line of the wafer exposed outside the annular element; dismantling said ring element; removing the backside film of the wafer; Metallization is applied to the front side of the wafer. 2. The wafer laser processing method as claimed in claim 1, characterized in that: after the front side of the wafer is metallized, it also includes the steps of sticking film, splitting, pouring film and expanding film on the back side of the wafer . 3. The wafer laser processing method according to claim 1, characterized in that: the annular element is made of metal. 4. The wafer laser processing method according to any one of claims 1-3, characterized in that: the ring-shaped element has a thickness ranging from 0.4 mm to 0.7 mm. 5. The wafer laser processing method according to any one of claims 1-3, characterized in that: the bottom surface of the inner edge of the annular element is provided with a step-shaped recess for accommodating the outer edge of the wafer. As for the groove, the depth of the step-shaped groove in the thickness direction of the annular element is in the range of 0.1 mm to 0.4 mm. 6 . The wafer laser processing method according to claim 1 , wherein the width of the outer edge of the wafer covered by the inner edge of the annular element is in the range of 0.2 mm to 1.5 mm.