CN112300708B

CN112300708B - UV-curable adhesive film and application thereof

Info

Publication number: CN112300708B
Application number: CN202011219361.7A
Authority: CN
Inventors: 翟丹; 艾瑞克·C·王; 徐杰
Original assignee: Shenzhen Unitak Electronic Materials Co ltd
Current assignee: Shenzhen Unitak Electronic Materials Co ltd
Priority date: 2020-11-04
Filing date: 2020-11-04
Publication date: 2022-09-30
Anticipated expiration: 2040-11-04
Also published as: CN112300708A

Abstract

A UV-curable adhesive film and an application thereof are disclosed, wherein the adhesive film comprises the following components by weight: 100 parts of basic polymer, 5-60 parts of UV curing resin, 1-5 parts of hardener, 0.1-5 parts of photoinitiator and 0.1-1.5 parts of release agent. The invention effectively reduces the adhesive force to the wafer die bond adhesive film after ultraviolet irradiation, obviously improves the success rate of wafer pickup, obviously reduces the requirement on the height of a thimble when the wafer is picked up, and simultaneously reduces the phenomena of wafer displacement, flying, fragmentation and the like.

Description

UV-curable adhesive film and application thereof

Technical Field

The invention relates to the technical field of UV adhesive production, in particular to a UV-curable cutting adhesive film for cutting and picking up ultrathin wafers and application thereof.

Background

During the manufacturing process of silicon wafers, the silicon wafers are usually cut into wafers with required sizes, and during the semiconductor manufacturing process, the wafers with engraved circuits are cut into small pieces and then enter the downstream processes. In the wafer cutting process, the wafer needs to be attached to a cutting tape so as to be convenient for accurate cutting. The picked wafer chip can be positioned and fixed by using the traditional die bonding glue. In recent years, due to miniaturization of devices and ultra-thinning of chips, new requirements are put on the die bonding process, and the traditional die bonding adhesive cement cannot meet the requirements. That is, in such application scenarios, the die bonding adhesive film is required to replace the die bonding adhesive paste to realize the die bonding process. The process usually needs a cutting adhesive tape capable of being cured by UV, and before cutting, a die bond adhesive film of a wafer is adhered to the cutting adhesive tape to prevent the wafer from displacing and facilitate cutting; after cutting, the ultraviolet curing adhesive layer on the cutting adhesive tape is cured through ultraviolet irradiation, so that the adhesive force between the ultraviolet curing adhesive and the die bonding adhesive film of the wafer is remarkably reduced, and the wafer is convenient to pick up. One of the advantages of the uv curable adhesive layer is that the adhesive force can be easily controlled by controlling the uv irradiation dose. In the prior art, the method mainly comprises the following two cutting processes: (1) adhering a die bond adhesive film of a wafer to an ultraviolet cutting adhesive tape, cutting, performing ultraviolet irradiation, and picking up the cut wafer; (2) after the die bonding adhesive film of the wafer is adhered to the ultraviolet cutting adhesive tape, ultraviolet irradiation is firstly carried out, then cutting is carried out, and finally the cut chips are picked up.

No matter which cutting process is adopted, the ultraviolet curing adhesive is required to have higher adhesive force before ultraviolet curing, so that displacement, flying and the like of chips are prevented, after the ultraviolet curing, the adhesive force between the ultraviolet curing adhesive and a die bonding adhesive film of a wafer needs to be as small as possible, and the wafer can be picked up. In addition, after the existing ultraviolet curing adhesive is irradiated by ultraviolet light, because the adhesive force of the existing ultraviolet curing adhesive to a die bond adhesive film on a wafer is still high, the wafer can be jacked up only by using a high thimble height, and the higher the thimble height is, the more easily the wafer is scattered and broken.

Disclosure of Invention

The invention provides a UV-curable adhesive film and application thereof.

According to a first aspect, an embodiment provides a UV-curable adhesive film, wherein the UV-curable adhesive comprises the following components by weight: 100 parts of basic polymer, 5-60 parts of UV curing resin, 1-5 parts of hardener, 0.1-5 parts of photoinitiator and 0.1-1.5 parts of release agent.

According to a second aspect, an embodiment provides an adhesive tape which is a film coated with the adhesive film of the first aspect.

According to a third aspect, an embodiment provides a use of the adhesive film of the first aspect in wafer dicing and/or pick-up.

According to the ultraviolet curing adhesive of the embodiment, the adhesive force of the ultraviolet irradiated adhesive to the wafer die bond adhesive film is effectively reduced, the success rate of picking up the wafer is obviously improved, the requirement on the height of a thimble during picking up the wafer is obviously reduced, and the phenomena of displacement, flying, fragmentation and the like of the wafer are reduced.

Drawings

Fig. 1-3 show views of the backside of a chip in one embodiment.

Detailed Description

The present invention will be described in further detail with reference to the following detailed description and accompanying drawings. Wherein like elements in different embodiments have been given like element numbers associated therewith. In the following description, numerous details are set forth in order to provide a better understanding of the present application. However, those skilled in the art will readily recognize that some of the features may be omitted or replaced with other elements, materials, methods in different instances. In some instances, certain operations related to the present application have not been shown or described in detail in order to avoid obscuring the core of the present application from excessive description, and it is not necessary for those skilled in the art to describe these operations in detail, so that they may be fully understood from the description in the specification and the general knowledge in the art.

Furthermore, the features, operations, or characteristics described in the specification may be combined in any suitable manner to form various embodiments. Also, the various steps or actions in the method descriptions may be transposed or transposed in order, as will be apparent to one of ordinary skill in the art. Thus, the various sequences in the specification and drawings are for the purpose of clearly describing certain embodiments only and are not intended to imply a required sequence unless otherwise indicated where a certain sequence must be followed.

The numbering of the components as such, e.g., "first", "second", etc., is used herein only to distinguish the objects as described, and does not have any sequential or technical meaning.

Herein, "die" may also be referred to as "wafer" or "chip".

Due to the trend of ultra-thinning of the existing wafers with smaller and smaller thicknesses, the thickness of the wafers is gradually reduced from 0.5mm to 0.1mm and is even thinner. For a wafer with a smaller thickness, the existing ultraviolet cutting adhesive tape still has strong adhesive force to a die bond adhesive film of the wafer after ultraviolet irradiation, which is not beneficial to picking up the wafer, and the phenomena of scattering, fragmentation and the like of a raw wafer can occur in the picking up process.

Herein, uv (ultraviolet) refers to ultraviolet rays unless otherwise specified.

According to a first aspect, an embodiment provides a UV-curable adhesive film comprising the following components: the coating comprises a base polymer, a UV curing resin, a hardening agent, a photoinitiator and a release agent.

In one embodiment, the composition comprises the following components by weight: 100 parts of basic polymer, 5-60 parts of UV curing resin, 1-5 parts of hardener, 0.1-5 parts of photoinitiator and 0.1-1.5 parts of release agent. Wherein, the weight parts of the UV curing resin can include but are not limited to 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, 36 parts, 37 parts, 38 parts, 39 parts, 40 parts, 41 parts, 42 parts, 43 parts, 44 parts, 45 parts, 46 parts, 47 parts, 48 parts, 49 parts, 50 parts, 51 parts, 52 parts, 53 parts, 54 parts, 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, 60 parts; the parts by weight of the hardener may include, but are not limited to, 1 part, 2 parts, 3 parts, 4 parts, 5 parts; the parts by weight of the photoinitiator may include, but is not limited to, 0.1 part, 0.2 part, 0.3 part, 0.4 part, 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1 part, 1.1 part, 1.2 part, 1.3 part, 1.4 part, 1.5 part, 1.6 part, 1.7 part, 1.8 part, 1.9 part, 2 parts, 2.1 part, 2.2 part, 2.3 part, 2.4 part, 2.5 part, 2.6 part, 2.7 part, 2.8 part, 2.9 part, 3 part, 3.1 part, 3.2 part, 3.3 part, 3.4 part, 3.5 part, 3.6 part, 3.7 part, 3.8 part, 3.9 part, 4 part, 4.1 part, 4.2 part, 4.3 part, 4.4 part, 4.5 part, 4.6 part, 4.7 part, 4.8 part, 4.9 part, 4.1 part, 4.2 part, 4.3 part, 4.3.4.4 part, 4.5 part, 4.6 part, 4.7 part, 4.8 part, 4.5 part, 4.6 part, 4.7 part, 4.8 part, 4.6 part, 4.7 part, 4.6 part, or more part of the like; the parts by weight of the release agent may include, but are not limited to, 0.1 part, 0.2 part, 0.3 part, 0.4 part, 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1 part, 1.1 part, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts.

In one embodiment, the UV-curable adhesive film is used for adhering the die bond adhesive film of the wafer to be cut to an ultraviolet-curable adhesive on a PO/PVC film base material and other film base materials before ultraviolet irradiation, after the ultraviolet irradiation, the adhesive force is obviously reduced, the picking of the chip is facilitated, and the UV-curable adhesive film is particularly suitable for picking up ultrathin wafers. The wafer thickness may be 0.1-0.5mm, including but not limited to 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, and the like. In one embodiment, the UV-curable adhesive film is provided for ultra-thin wafer dicing and pick-up, typically referred to as sub-100 μm wafers.

In one embodiment, the composition comprises the following components by weight: 100 parts of basic polymer, 40 parts of UV curing resin, 3 parts of hardener, 0.5-3.5 parts of photoinitiator and 0.35-1.4 parts of release agent.

In one embodiment, the composition comprises the following components by weight: 100 parts of basic polymer, 40 parts of UV curing resin, 3 parts of hardener, 0.6-3.2 parts of photoinitiator and 0.35-1.4 parts of release agent.

In one embodiment, the composition comprises the following components by weight: 100 parts of basic polymer, 40 parts of UV curing resin, 3 parts of hardener, 0.6-3.2 parts of photoinitiator and 1.4 parts of release agent.

In one embodiment, the composition comprises the following components by weight: 100 parts of basic polymer, 40 parts of UV curing resin, 3 parts of hardener, 1.8-3.2 parts of photoinitiator and 1.4 parts of release agent.

In one embodiment, the composition comprises the following components by weight: 100 parts of basic polymer, 40 parts of UV curing resin, 3 parts of hardener, 1.91-3.11 parts of photoinitiator and 1.4 parts of release agent.

In an embodiment, the base polymer includes, but is not limited to, at least one of an acrylate rubber, a thermoplastic polyurethane elastomer rubber (TPU).

In one embodiment, the acrylate rubber includes, but is not limited to, at least one of Nipol AR53L, AR12, AR32, AR72LS, Teisan Resin SG-P3, SG-80H, SG-280TEA, SG-600TEA, SG-790.

In one embodiment, the acrylate rubber is selected from at least one of Nipol AR53L, AR12, AR32, and AR72LS manufactured by kumquat co.

In one embodiment, the base polymer has a glass transition temperature ≦ 20 ℃.

In one embodiment, the UV curable resin includes, but is not limited to, a polymerizable urethane acrylate oligomer.

In one embodiment, the polymerizable urethane acrylate oligomer includes, but is not limited to, at least one of the following components:

1) art Resin UN-3320HA, UN-3320HB, UN-3320HC, UN-3320HS, UN-904, manufactured by Negami Kogyo Co., Ltd;

2) UA-306H (pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer), UA-306T (pentaerythritol triacrylate toluene diisocyanate urethane prepolymer), UA-306I (pentaerythritol triacrylate isophorone diisocyanate urethane prepolymer), UA-510H (dipentaerythritol pentaacrylate hexamethylene diisocyanate urethane prepolymer) produced by Kyoeisha Kagaku co.;

3) UX-5000, UX-5002D-M20, UX-5003D, UX-5005 and DPHA-40H manufactured by Nihon KayakuCo;

4) UV-1700B, UV-7550B, UV-7600B, UV-7605B, UV-7610B, UV-7620EA and UV-7630B, UV-7640B, UV-7650B manufactured by Nihon Gosei Kagaku Kogyo Co;

5) u-4HA, U-6LPA, UA-1100H, UA-53H, UA-33H manufactured by Shin-Nakamura Kagaku Kogyo Co.

In one embodiment, the hardener includes, but is not limited to, at least one of a polyisocyanate, a polyurethane prepolymer, and the like.

In one embodiment, the polyisocyanate includes, but is not limited to, at least one of Coronate HL, Coronate HX, Coronate L, Coronate 1050, Coronate 2507, Coronate 3030E, and the like, manufactured by Nippon Polyurethane Industry co.

In one embodiment, the polyurethane prepolymer includes, but is not limited to, at least one of toluene diisocyanate (tdi), Hexamethylene Diisocyanate (HDI), HT100 (hexamethylene diisocyanate based polyisocyanate), HT600, N3390, and the like.

In one embodiment, the photoinitiator includes, but is not limited to, at least one of Irgacure 184 (1-hydroxycyclohexyl phenyl ketone), Irgacure 2959 (2-hydroxy-4' - (2-hydroxyethoxy) -2-methylpropiophenone), Irgacure 127, Darocur 1173, Irgacure 819, Darocur 4265, Darocur TPO, Irgacure 2100, Irgacure 784, Irgacure 250, LUCIRIN TPO, Irgacure 651(α, α -dimethylbenzylketal), and the like.

In one embodiment, the mold release agent includes, but is not limited to, at least one of US-270, US-350, US-352m, US-380, US-413, US-450, ACTFLOW UTMM-LS2, IBMGV-LS2, IBMGV-LS4, DAIAROMER SP-712, DAIAROMERS P-2105, manufactured by Soken Chemical & Engineering Co., Ltd., and the like, manufactured by Toaysian corporation (TOAGOSEI Co., Ltd.).

In one embodiment, the adhesive film is used for bonding a wafer.

In one embodiment, the adhesive film is used for bonding the wafer during wafer cutting.

In one embodiment, the thickness of the wafer is less than or equal to 100 μm, such wafer is usually called as an ultra-thin wafer, and after the wafer is bonded and fixed by using the existing glue film and is cut, the wafer needs to be lifted up by using a higher pin height during picking up, which is likely to cause the wafer to scatter and break. The adhesive film can obviously reduce the adhesive force to the wafer after UV irradiation, further reduce the requirement on the height of a thimble, and effectively reduce or even avoid the flying and the fragmentation of the wafer.

In one embodiment, the film is a polypropylene film. When in use, the wafer to be cut is adhered to the adhesive film of the adhesive tape. Typically, one surface of the film is coated with the adhesive film of the first aspect.

In the following examples, the components are specified as follows:

the base polymer was an acrylate rubber (ACM) manufactured by Nipol corporation of Zeon, model No. Nipol AR 53L.

The UV curable Resin was Art Resin UN-3320HA manufactured by Nissan Kogyo Co., Ltd. (Negami Kogyo Co.).

The hardener 1 was Coronate HL produced by Nippon Polyurethane Industry co.

The curing agent 2 is hexamethylene diisocyanate-based polyisocyanate (HT100) produced by Wawa chemical group Co., Ltd.

Photoinitiator 1 was Darocur 1173 from Pasteur, Germany.

Photoinitiator 2 was Darocur 4265 manufactured by Pasteur, Germany.

The photoinitiator 3 was Irgacure 651 manufactured by basf, germany.

The photoinitiator 4 was Irgacure 784, manufactured by Pasteur, Germany.

The release agent was ACTFLOW UTMM-LS2 manufactured by Soken Chemical & Engineering Co., Ltd.

In the following examples, the UV curing strength was 1500- ² Irradiation was carried out using an ultraviolet high-pressure mercury lamp.

In the following examples, the peel strength test method followed ASTM-D3330, the pressure sensitive tape peel strength test standard of the American Society for Testing and Materials (ASTM), which was mainly used for the 180 DEG peel strength test of the pressure sensitive tape, and the instrument used in the following examples was an Instron Universal tensile tester.

In the following examples, ATB-130U is a die bond film (30 μm thickness) available from Henkel Loctite.

Example 1

This example provides a UV curable adhesive film having a composition, by weight, as shown in table 1:

TABLE 1

It can be seen that the UDT-801 group has higher peel strength before UV irradiation and lower peel strength after UV irradiation, and belongs to a formula with better performance. In order to compare the performance of each group, the formulation and experimental results of the UDT-801 group in this example are also put into the following tables.

Example 2

This example provides a UV curable adhesive film having a composition, by weight, as shown in table 2:

TABLE 2

Example 3

This example provides a UV curable adhesive film having a composition, by weight, as shown in table 3:

TABLE 3

Example 4

This example provides a UV-curable adhesive film having a composition, by weight, as shown in table 4:

TABLE 4

Example 5

This example provides a UV curable adhesive film having a composition, by weight, as shown in table 5:

TABLE 5

Example 6

This example provides a UV curable adhesive film having a composition, by weight, as shown in table 6:

TABLE 6

Thimble height test experiment

In this test experiment, the picked-up chip had a thickness of 3mil (about 76.2 μm) and a size of 10X 8 mm.

Table 7 statistical table of wafer pick-up yield

In Table 7, it is indicated that chip chipping occurred during the pick-up of a chip having a thickness of 3mil (about 76.2 μm) at a pin height of 0.3 mm.

In Table 7, using the results of the UDT-801 set 0.1mm pin height test as an example, 0/25 shows that the number of qualified wafers is 0 out of 25 wafers picked up under the condition of 0.1mm pin height.

The rear view of the UDT-921 set chip is shown in FIGS. 1 to 3, FIG. 1 is a photograph of the rear of the chip magnified 50 times, and FIGS. 2 and 3 are photographs of the rear of the chip magnified 100 times. As can be seen from the figures 1, 2 and 3, the chip is completely and clearly cut, and the chip corner has no phenomena of fragmentation, film drawing or falling off and the like.

In table 7, the yield refers to the ratio of the number of non-chipped wafers after picking to the total number of wafers picked.

As can be seen from Table 7, the UDT-801 group can reduce the height of the thimble to 0.2mm, and when the height of the thimble is 0.2mm or more, the qualification rate of the picked wafer is up to 100%; the UDT-921 group, UDT-922 group and UDT-923 group can reduce the height of the thimble to 0.1mm, when the height of the thimble is 0.1mm, the qualification rate of the picked wafer is respectively up to 96%, 92% and 93%, and when the height of the thimble is 0.2mm or more, the qualification rate of the picked wafer is up to 100%.

Test for Peel Strength

TABLE 8

All peel strengths in Table 8 are in units of N/20 mm.

In table 8, the self-adhesion test method refers to the method in ASTM D6195-03(2019), i.e., Loop Tack test method, and the data obtained is expressed in N.

In Table 8, ATB-130U is a die bond film (30 μm thick) available from Henkel Loctite. FH-925 is a die bond film (25 μm thickness) available from Hitachi Chemical.

In table 8, 3mil is about 76.2 μm because 1mil is 1/1000inch and 0.0254mm is 25.4 μm.

In table 8, the reason why the adhesion of the wafer attachment ring needs to be measured is that the dicing tape comes off from the metal ring if there is no adhesion after UV irradiation, and therefore, it is necessary to maintain a certain adhesion after UV irradiation.

In table 8, the ultraviolet irradiation process is performed, and the standard process refers to cutting and then UV irradiation. The non-standard procedure is UV irradiation followed by cutting.

In table 8, the method for determining whether chip displacement occurs is as follows: the chip edge is neat after cutting (i.e. no Chipping phenomenon, also can be expressed as the phenomenon of no cutting irregularity). The most extreme displacement of the chip is if the diced chip is somewhat detached.

In table 8, "whether or not a wafer of 3mil thickness (standard method, 300ms, 0.3mm) can be picked up" means as follows: the standard method refers to a pick-up success rate of 100%. 300ms means pick-up speed and 0.3mm means ejector pin height.

Control 1 was an adhesive obtained from Kagaku corporation, and control 2 was an adhesive obtained from Kogaku corporation, Furukawa.

As can be seen from the results in table 8, the adhesion force to the wafer attachment ring before and after UV irradiation in control group 1 did not meet the index requirements, and the peel strength of control group 2 adhered to FH-925 after UV irradiation was high, making it difficult to pick up the wafer and easily causing chipping of the wafer. In the embodiment of the invention, all indexes of the UDT-921 group meet the requirements.

The present invention has been described in terms of specific examples, which are provided to aid understanding of the invention and are not intended to be limiting. For a person skilled in the art to which the invention pertains, several simple deductions, modifications or substitutions may be made according to the idea of the invention.

Claims

1. A UV-curable adhesive film is characterized by comprising the following components in parts by weight: 100 parts of basic polymer, 40 parts of UV curing resin, 3 parts of hardener, 1.8-3.2 parts of photoinitiator and 1.4 parts of release agent;

the base polymer is selected from acrylate rubbers selected from Nipol AR 53L;

the UV curing Resin is selected from the group consisting of Art Resin UN-3320 HA;

the hardener is selected from hexamethylene diisocyanate based polyisocyanates;

the photoinitiator is selected from at least one of Darocur 1173, Darocur 4265 and Irgacure 651;

the release agent is selected from ACTFLOW UTMM-LS 2.

2. The glue film of claim 1, comprising, by weight: 100 parts of basic polymer, 40 parts of UV curing resin, 3 parts of hardener, 1.91-3.11 parts of photoinitiator and 1.4 parts of release agent.

3. An adhesive film according to claim 1, wherein the adhesive film is used for bonding a wafer.

4. The adhesive film of claim 3, wherein the adhesive film is used for bonding the wafer during wafer dicing.

5. An adhesive film according to claim 3, wherein the thickness of the wafer is less than or equal to 100 μm.

6. An adhesive tape, characterized in that it is a film coated with the adhesive film according to any one of claims 1 to 5.

7. The tape of claim 6 wherein the film is a polypropylene film.

8. Use of the adhesive film according to any one of claims 1 to 5 for wafer dicing and/or pick-up.