Chip scratching film and preparation method thereof

Abstract

The invention discloses a chip scratching film and a preparation method thereof, and relates to the technical field of wafer cutting protective films. Comprising a base material layer, a silicone oil layer is arranged on one side of the base material layer, an antistatic layer is arranged on the other side of the base material layer, and the silicone oil layer comprises silicon-free areas which are arranged at intervals and used for placing wafers. The thickness of the base material layer ranges from 0.02 mm to 0.1 mm. The silicon-free area is circular, and the diameter of the silicon-free area is 90-130 mm. Protection can be provided in the wafer cutting process, and silicon pollution is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of scribing films, in particular to a chip scribing film and a preparation method thereof. Background Art

[0002] In the process of manufacturing semiconductor chips, cutting semiconductor wafers to obtain semiconductor chips is a necessary step. To ensure the production yield and efficiency of the chips, semiconductor chip cutting tapes are required to protect, fix, and carry the chips. The semiconductor chip cutting tape needs to keep the wafer and the chip firmly bonded during the cutting stage and enable the convenient peeling and picking up of the chip after cutting. After the wafer particles treated by cutting are attached through the wafer expansion film, they will enter the subsequent expansion process for further processing.

[0003] In the prior art, for the existing protective tapes for wafer cutting, in order to facilitate better peeling and picking up after wafer cutting, a release layer is generally provided, and this release layer mostly uses silicone materials, which has significant technical defects: First, as the interface layer directly contacting the wafer, silicone oil residues are easily attached to the surface of the crystal grains. Statistical data shows that this pollution causes a 3 - 6% decrease in the product yield; Second, to eliminate silicon residues, a complex cleaning process needs to be added, which not only increases the process complexity but also significantly raises the production cost. The above two defects ultimately lead to the difficulty in meeting the comprehensive product yield standard and the high manufacturing cost.

[0004] To solve the above problems, a new chip scribing film is needed, which can provide protection during the wafer cutting process and has no silicon pollution. Summary of the Invention

[0005] The main technical problem to be solved by the present invention is to provide a chip scribing film and a preparation method thereof, which can provide protection during the wafer cutting process and have no silicon pollution.

[0006] To solve the above technical problem, one technical solution adopted by the present invention is:

[0007] A chip scribing film includes a substrate layer. On one side of the substrate layer, a silicone oil layer is provided, and on the other side, an antistatic layer is provided. The silicone oil layer includes silicon - free areas arranged at intervals for placing wafers.

[0008] Further, the substrate layer is one of a polyolefin film layer, a polyester film layer, or a polyolefin - polyester modified film layer.

[0009] Further, the thickness of the substrate layer is 0.02 mm - 0.1 mm.

[0010] Further, the silicon - free area is circular, and the diameter is 90 mm - 130 mm.

[0011] Furthermore, the silicone oil layer has a uniformly arranged grid, and the size of the grid is 0.001 mm - 2 mm.

[0012] Furthermore, the grammage per square meter of the silicone oil layer is 0.01 - 2 g / m 2 .

[0013] Furthermore, the silicone oil layer is one of a silicone layer, a thermosetting silicone oil layer, a UV silicone oil layer, or an aqueous silicone oil layer.

[0014] A method for preparing a chip scribing film: includes the steps of: unwinding the base material; coating / screen printing the silicone oil layer; performing the first curing treatment; winding the semi-finished product; unwinding the semi-finished product base material; corona treating the semi-finished product base material; coating the antistatic layer; performing the second curing treatment; trimming the edges; winding the finished product.

[0015] Furthermore, the equipment used for the preparation is a screen printing device, a coater, or a printing press; when using a screen printing device, the silicone oil layer is formed by screen printing; when using a coater or a printing press, the silicone oil layer is formed by coating, and the base material needs to be corona treated after unwinding the base material.

[0016] Furthermore, the curing treatment method is thermal curing or UV lamp curing.

[0017] The beneficial technical effects of the present invention are:

[0018] For the chip scribing film prepared by this preparation method, during use, due to the design of the silicon-free area, the wafer can be directly placed in contact with the base material layer in the silicon-free area, significantly reducing the risk of silicone oil adhering to the surface of the die, thereby improving the product yield. After the wafer cutting is completed, the expansion film covers the die. Since the periphery of the silicon-free area is the silicone oil layer and has a grid structure, it can effectively promote gas discharge and better fit with the expansion film. In addition, due to the release function of the silicone oil layer, it can also ensure the smooth peeling of the expansion film. Description of the Drawings

[0019] Figure 1 is a schematic structural diagram (layer structure schematic diagram) of the chip scribing film of the present invention;

[0020] Figure 2 is a schematic structural diagram (structural schematic diagram of the silicone oil layer) of the chip scribing film of the present invention;

[0021] The marks of each part in the drawings are as follows:

[0022] 1. Base material layer; 2. Silicone oil layer; 21. Silicon-free area; 22. Grid; 3. Antistatic layer. Detailed Embodiments

[0023] In order to clearly understand the technical means of the present invention and be able to implement it according to the content of the specification, the following further describes in detail the specific implementation manners of the present invention in conjunction with the accompanying drawings and embodiments. The following embodiments are used to illustrate the present invention, but not to limit the scope of the present invention.

[0024] Example 1

[0025] In this example, a screen printing device is used to prepare a chip scribing film. The specific steps include: unwinding the substrate layer, then coating a silicone oil layer on one side of the substrate layer through the screen printing device to form a pattern with non-silicone areas arranged at intervals, and then performing heat curing treatment to cure the silicone oil layer on the substrate layer. Next, unwind the semi-finished substrate, perform corona treatment on the semi-finished substrate to improve the adhesion of the antistatic layer, then coat the antistatic layer on the other side of the substrate layer, and perform a second heat curing treatment. Finally, perform edge trimming and wind up the finished product. In this example, the substrate layer is made of a polyolefin film layer with a thickness of 0.05 mm. The non-silicone areas are circular with a diameter of 110 mm. The silicone oil layer has uniformly arranged grids with a size of 0.1 mm.

[0026] Example 2

[0027] In this example, a coating machine is used to prepare a chip scribing film. The specific steps are the same as those in Example 1, except for the method of coating the silicone oil layer and the pretreatment before coating the silicone oil layer. In this example, after unwinding the substrate, corona treatment needs to be performed on the substrate, and the silicone oil layer is coated on the substrate layer by a coating machine to form a pattern with non-silicone areas arranged at intervals. The remaining steps and parameters are the same as those in Example 1, and the curing method is still heat curing.

[0028] Example 3

[0029] In this example, a printing machine is used to prepare a chip scribing film. The specific steps are the same as those in Example 1, except for the method of coating the silicone oil layer and the pretreatment before coating the silicone oil layer. In this example, after unwinding the substrate, corona treatment needs to be performed on the substrate, and the silicone oil layer is printed on the substrate layer by a printing machine to form a pattern with non-silicone areas arranged at intervals. The remaining steps and parameters are the same as those in Example 1, and the curing method is still heat curing.

[0030] Example 4

[0031] The difference between this example and Example 3 lies in the curing method. In this example, the UV lamp curing method is used to replace the heat curing method, and the remaining steps and parameters are the same as those in Example 3. It should be noted that in this example, UV photosensitizers are added to both the silicone oil layer and the antistatic layer.

[0032] The finished chip scribing films produced in Examples 1-4, such as Figures 1 to 2As shown in the figure: it includes a substrate layer 1, a silicone oil layer 2 is provided on one side of the substrate layer, and an antistatic layer 3 is provided on the other side. The silicone oil layer includes silicon-free areas 21 arranged at intervals for placing wafers. The silicon-free areas are circular. The silicone oil layer has uniformly arranged grids 22.

[0033] Among them, it is worth noting that the silicon-free areas are empty areas formed by screen printing / coating. There is no silicone oil medium in this area, and the wafers can directly contact the substrate layer. This effectively avoids the problem of silicone oil migration and contamination.

[0034] Comparative Example 1: In this comparative example, a chip dicing film without silicon-free areas is prepared. The specific steps are the same as those in Example 3, but when coating the silicone oil layer, silicon-free areas arranged at intervals are not formed, but the entire silicone oil layer is uniformly coated on the substrate layer. The remaining steps and parameters are the same as those in Example 3.

[0035] The main parameters of the equipment used in the preparation of Examples 1-3 are compared, as shown in Table 1.

[0036] Table 1

[0037] Substrate width (mm) Speed (m / min) <![CDATA[Coating weight (g / m 2 )]]> <![CDATA[Coating accuracy (g / m 2 )]]> Example 1 400 20 2 2±0.3 Example 2 1100 150 0.5 0.5±0.1 Example 3 320 40 1 1±0.2

[0038] The curing times of Examples 3 and 4 and the chip dicing film samples prepared are tested and compared. The results are shown in Table 2.

[0039] Table 2

[0040] Curing time (S) Interlayer adhesion force (N) Heat resistance (℃) Example 3 30 4.2 150 Example 4 0.5 3.8 120

[0041] The chip dicing film samples prepared in Example 3 and Comparative Example 1 are tested and compared. The results are shown in Table 3.

[0042] Table 3

[0043] Grain silicone oil contamination rate (%) Example 3 0.07 Comparative Example 1 4.3

[0044] The test methods for Table 2 and Table 3 are as follows:

[0045] Curing time: Use a stopwatch to record the time required from the start of curing until the surface of the material is completely hardened. The test environment temperature is 25±2°C, and the humidity is 50±5%RH.

[0046] Interlayer adhesion: Refer to the GB / T 2792-2014 standard, adopt the 90° peeling method, and use a universal material testing machine to test at a rate of 300 mm / min.

[0047] Heat resistance: Place the sample in a constant temperature oven, heat it to the set temperature at a rate of 10°C / min and keep it for 30 minutes, and then observe the highest tolerance temperature without delamination or blistering on the surface.

[0048] Grain silicone oil contamination rate: Use an energy dispersive spectrometer (EDS) to randomly sample 10 points on the surface of the wafer, and calculate the average value of the proportion of the area with abnormal silicon element enrichment.

[0049] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A chip scratching film, characterized in that: The invention comprises a substrate layer (1), a silicone oil layer (2) is arranged on one side of the substrate layer, and an antistatic layer (3) is arranged on the other side of the substrate layer, wherein the silicone oil layer comprises silicon-free areas (21) arranged at intervals for placing wafers.

2. The chip cleaving film according to claim 1, characterized in that: The substrate layer is one of a polyolefin film layer, a polyester film layer or a polyolefin polyester modified film layer.

3. The chip cleaving film according to claim 1, characterized in that: The thickness of the substrate layer is 0.02 mm-0.1 mm.

4. The chip cleaving film according to claim 1, characterized in that: The silicon-free area is circular and has a diameter of 90 mm to 130 mm.

5. The chip cleaving film according to claim 1, characterized in that: The silicone oil layer has evenly arranged grids (22), and the size of the grids is 0.001 mm-2 mm.

6. The chip cleaving film according to claim 1, characterized in that: The square gram weight of the silicone oil layer is 0.01-2g / m 2 .

7. The method for preparing a chip scribing film according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: substrate unwinding; coating / screen printing a silicone oil layer; first curing treatment; semi-finished product winding; semi-finished product substrate unwinding; corona treatment of the semi-finished product substrate; antistatic layer coating; second curing treatment; edge treatment; and finished product winding.

8. The method for preparing a chip scribing film according to claim 7, characterized in that: The equipment used in the preparation is a screen printing device, a coater or a printer; when a screen printing device is used, the silicone oil layer is formed by silk screen printing; when a coater or a printer is used, the silicone oil layer is formed by coating, and the substrate needs to be corona treated after the substrate is unwound.

9. The method for preparing a chip scribing film according to claim 7, characterized in that: The curing treatment is performed by heat curing or UV lamp curing.

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