A surface anti-oxidation treatment method for silicon aluminum wire for wire bonding

Abstract

The present invention discloses a surface anti-oxidation treatment method for silicon aluminum wire for wire bonding, which relates to the technical field of electronic packaging materials. The present invention can achieve surface anti-oxidation treatment of silicon aluminum wire through a conventional coating method, and utilizes an anti-oxidation coating to form a dense and wear-resistant anti-oxidation coating on the surface of the silicon aluminum wire, thereby significantly improving the anti-oxidation performance of the silicon aluminum wire and better preventing the surface oxidation phenomenon of the silicon aluminum wire after long-term contact with air, thereby ensuring the use effect of the bonding wire and extending the service life of the bonding wire.

Description

Technical field:

[0001] The invention relates to the technical field of electronic packaging materials, and in particular to a surface anti-oxidation treatment method for silicon aluminum wires for wire bonding. Background technology:

[0002] Wire bonding uses thin metal wires, employing heat, pressure, and ultrasonic energy to tightly weld metal leads to substrate pads, achieving electrical interconnection between the chip and substrate and information exchange between chips. Under ideal control conditions, electron sharing or atomic interdiffusion occurs between the wires and substrate, achieving an atomic-scale bond between the two metals. Wire bonding is used to introduce and remove electrical connections from core components and is widely used in the packaging of discrete semiconductor devices and integrated circuits.

[0003] Based on the basic material, the four main types of bonding wires commonly used in the market are gold bonding wire, silver bonding wire, copper bonding wire, and aluminum bonding wire. Aluminum bonding wire is more cost-effective. However, ordinary aluminum wire is prone to surface oxidation when exposed to air, which not only affects the wire's conductivity but also its physical properties. This makes it very easy for the wire to collapse or break during the electronic packaging process, resulting in significant production losses.

[0004] Silicon-aluminum wire, also known as bonding wire, is composed of aluminum and silicon. It possesses excellent electrical and thermal conductivity, effectively transferring electronic signals and heat energy, making the performance of electronic components more stable and reliable. It is primarily used for ultrasonic bonding wires in semiconductor devices such as integrated circuits and crystals. This invention significantly improves the oxidation resistance of the silicon-aluminum wire by subjecting it to a surface anti-oxidation treatment, thereby ensuring the effectiveness of the bonding wire and extending its service life. Summary of the invention:

[0005] The technical problem to be solved by the present invention is to provide a surface anti-oxidation treatment method for silicon aluminum wire for wire bonding, which can make the silicon aluminum wire have excellent anti-oxidation performance, effectively extend the service life of the bonding wire while ensuring the use effect of the bonding wire.

[0006] The technical problem to be solved by the present invention is achieved by adopting the following technical solutions:

[0007] One of the purposes of the present invention is to provide a surface anti-oxidation treatment method for silicon aluminum wire for wire bonding, wherein an anti-oxidation coating is evenly coated on the surface of the silicon aluminum wire and an anti-oxidation coating is formed after curing.

[0008] Preferably, the thickness of the anti-oxidation coating is 20 to 50 μm. The appropriate thickness of the anti-oxidation coating is determined according to actual needs.

[0009] Preferably, the antioxidant coating comprises the following components by weight: 100 parts acrylaminosilane-modified epoxy resin, 15-25 parts silicon nitride powder, 10-20 parts nano-alumina, 15-25 parts curing agent, 0-5 parts curing accelerator, and 0.5-5 parts defoaming agent. The silicon nitride powder and nano-alumina act as fillers, improving the coating's density, toughness, wear resistance, and high-temperature oxidation resistance. The curing accelerator may or may not be added, depending on the actual curing conditions.

[0010] Preferably, the curing agent is one or more of aliphatic amines, alicyclic amines, aromatic amines, polyetheramines, and polyamides. The curing agent chemically reacts with the epoxy resin to form a three-dimensional network polymer. Different curing temperatures and times are set for different curing agents.

[0011] Preferably, the curing accelerator is 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30). The function of the curing accelerator is to accelerate the curing reaction or reduce the curing temperature.

[0012] Preferably, the defoamer is an organosilicon defoamer, which eliminates foam formed during the production process of the coating.

[0013] Preferably, the preparation method of the acrylaminosilane-modified epoxy resin is: first, the epoxy resin and the catalyst are evenly mixed, then 1,1,1-trimethyl-N-2-propylenepropylaminosilane and an initiator are added, and the temperature is raised to react to obtain the acrylaminosilane-modified epoxy resin.

[0014] Preferably, the epoxy resin is bisphenol A epoxy resin.

[0015] Preferably, the initiator is one or more of azobisisobutyronitrile and azobisisoheptanenitrile. Other types of initiators besides azo initiators, such as organic peroxide initiators, may also be used.

[0016] Preferably, the catalyst is one or more of triphenylphosphine and bis(triphenylphosphine)palladium acetate. Irradiation technology can also be used to shorten the reaction time and accelerate the reaction rate.

[0017] Preferably, the mass ratio of the epoxy resin, 1,1,1-trimethyl-N-2-propylenepropylaminosilane, initiator and catalyst is (80-100):(15-30):(0.5-1):(0.05-0.1).

[0018] 1,1,1-Trimethyl-N-2-propylenepropylaminosilane, CAS number: 10519-97-8.

[0019] A second object of the present invention is to provide a silicon aluminum wire for wire bonding prepared according to the aforementioned surface anti-oxidation treatment method.

[0020] The beneficial effects of the present invention are as follows: the present invention can achieve surface antioxidant treatment of silicon aluminum wire through conventional coating methods, and utilizes antioxidant coating to form a dense and wear-resistant antioxidant coating on the surface of the silicon aluminum wire, thereby significantly improving the antioxidant performance of the silicon aluminum wire, and better preventing the silicon aluminum wire from surface oxidation after long-term contact with air, thereby ensuring the use effect of the bonding wire and extending the service life of the bonding wire. Specific implementation method:

[0021] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific embodiments.

[0022] Description of raw materials in the following examples and comparative examples:

[0023] The bisphenol A epoxy resin is bisphenol A epoxy resin E51;

[0024] The purity of silicon nitride powder is 99.9% and the particle size is 50-100nm;

[0025] The purity of nano-alumina is 99.99% and the particle size is 20-50nm;

[0026] The polyetheramine was BASF polyetheramine D230;

[0027] The organosilicon defoamer is organosilicon defoamer BYK-024;

[0028] The silicon aluminum wire was purchased from Jinao Xindian (Beijing) Technology Co., Ltd., with a diameter of 0.025 mm, an elongation of 1-4%, and a breaking force of 15-18 cN.

[0029] Example 1

[0030] 1. Preparation of acrylaminosilane modified epoxy resin

[0031] First, 100 parts of bisphenol A epoxy resin and 0.1 parts of triphenylphosphine were evenly mixed, and then 30 parts of 1,1,1-trimethyl-N-2-propylenepropylaminosilane and 0.5 parts of azobisisobutyronitrile were added. The temperature was raised to 100°C for reaction. The reaction was stopped when the viscosity of the reaction liquid no longer changed within 15 minutes to obtain acrylaminosilane-modified epoxy resin.

[0032] 2. Preparation of antioxidant coating

[0033] 100 parts of the prepared acrylaminosilane-modified epoxy resin, 15 parts of silicon nitride powder, 15 parts of nano-alumina and 1 part of an organosilicon defoamer were mixed uniformly to obtain component A.

[0034] Mix 20 parts of polyetheramine and 5 parts of DMP-30 to obtain component B.

[0035] Component A and component B are uniformly mixed in a weight ratio of 1:1 to obtain an antioxidant coating.

[0036] 3. Surface anti-oxidation treatment of silicon aluminum wire

[0037] The above-prepared anti-oxidation coating was evenly coated on the surface of the silicon aluminum wire by a coating machine, and after curing (25°C / 36h), an anti-oxidation coating with a thickness of 25 μm was formed.

[0038] Example 2

[0039] 1. Preparation of acrylaminosilane modified epoxy resin

[0040] First, 100 parts of bisphenol A epoxy resin and 0.1 parts of triphenylphosphine were evenly mixed, and then 20 parts of 1,1,1-trimethyl-N-2-propylenepropylaminosilane and 0.5 parts of azobisisobutyronitrile were added. The temperature was raised to 100°C for reaction. The reaction was stopped when the viscosity of the reaction liquid no longer changed within 15 minutes to obtain acrylaminosilane-modified epoxy resin.

[0041] 2. Preparation of antioxidant coating

[0042] 100 parts of the prepared acrylaminosilane-modified epoxy resin, 20 parts of silicon nitride powder, 15 parts of nano-alumina and 1 part of an organosilicon defoamer were mixed uniformly to obtain component A.

[0043] Mix 20 parts of polyetheramine and 3 parts of DMP-30 to obtain component B.

[0044] Component A and component B are uniformly mixed in a weight ratio of 1:1 to obtain an antioxidant coating.

[0045] 3. Surface anti-oxidation treatment of silicon aluminum wire

[0046] The above-prepared anti-oxidation coating was evenly coated on the surface of the silicon aluminum wire by a coating machine, and after curing (25°C / 36h), an anti-oxidation coating with a thickness of 25 μm was formed.

[0047] Example 3

[0048] 1. Preparation of acrylaminosilane modified epoxy resin

[0049] First, 100 parts of bisphenol A epoxy resin and 0.1 parts of bis(triphenylphosphine)palladium acetate were evenly mixed, and then 25 parts of 1,1,1-trimethyl-N-2-propylenepropylaminosilane and 0.5 parts of azobisisoheptonitrile were added. The temperature was raised to 100° C. for reaction. The reaction was stopped when the viscosity of the reaction liquid no longer changed within 15 minutes to obtain acrylaminosilane-modified epoxy resin.

[0050] 2. Preparation of antioxidant coating

[0051] 100 parts of the prepared acrylaminosilane-modified epoxy resin, 25 parts of silicon nitride powder, 10 parts of nano-alumina and 1 part of an organosilicon defoamer were mixed uniformly to obtain component A.

[0052] Mix 20 parts of polyetheramine and 4 parts of DMP-30 to obtain component B.

[0053] Component A and component B are uniformly mixed in a weight ratio of 1:1 to obtain an antioxidant coating.

[0054] 3. Surface anti-oxidation treatment of silicon aluminum wire

[0055] The above-prepared anti-oxidation coating was evenly coated on the surface of the silicon aluminum wire by a coating machine, and after curing (25°C / 36h), an anti-oxidation coating with a thickness of 35 μm was formed.

[0056] Example 4

[0057] 1. Preparation of acrylaminosilane modified epoxy resin

[0058] First, 80 parts of bisphenol A epoxy resin and 0.1 parts of bis(triphenylphosphine)palladium acetate were evenly mixed, and then 15 parts of 1,1,1-trimethyl-N-2-propylenepropylaminosilane and 0.5 parts of azobisisoheptonitrile were added. The temperature was raised to 100°C for reaction. The reaction was stopped when the viscosity of the reaction liquid no longer changed within 15 minutes to obtain acrylaminosilane-modified epoxy resin.

[0059] 2. Preparation of antioxidant coating

[0060] 100 parts of the prepared acrylaminosilane-modified epoxy resin, 25 parts of silicon nitride powder, 10 parts of nano-alumina and 1 part of an organosilicon defoamer were mixed uniformly to obtain component A.

[0061] Mix 25 parts of diethylenetriamine and 2 parts of DMP-30 to obtain component B.

[0062] Component A and component B are uniformly mixed in a weight ratio of 1:1 to obtain an antioxidant coating.

[0063] 3. Surface anti-oxidation treatment of silicon aluminum wire

[0064] The above-prepared anti-oxidation coating was evenly coated on the surface of the silicon aluminum wire by a coating machine, and after curing (25°C / 24h), an anti-oxidation coating with a thickness of 35 μm was formed.

[0065] Example 5

[0066] 1. Preparation of acrylaminosilane modified epoxy resin

[0067] First, 90 parts of bisphenol A epoxy resin and 0.1 parts of bis(triphenylphosphine)palladium acetate were evenly mixed, and then 20 parts of 1,1,1-trimethyl-N-2-propylenepropylaminosilane and 0.5 parts of azobisisobutyronitrile were added. The temperature was raised to 100°C for reaction. The reaction was stopped when the viscosity of the reaction liquid no longer changed within 15 minutes to obtain acrylaminosilane-modified epoxy resin.

[0068] 2. Preparation of antioxidant coating

[0069] 100 parts of the prepared acrylaminosilane-modified epoxy resin, 20 parts of silicon nitride powder, 15 parts of nano-alumina and 1 part of an organosilicon defoamer were mixed uniformly to obtain component A.

[0070] Mix 25 parts of diethylenetriamine and 3 parts of DMP-30 to obtain component B.

[0071] Component A and component B are uniformly mixed in a weight ratio of 1:1 to obtain an antioxidant coating.

[0072] 3. Surface anti-oxidation treatment of silicon aluminum wire

[0073] The above-prepared anti-oxidation coating was evenly coated on the surface of the silicon aluminum wire by a coating machine, and after curing (25°C / 24h), an anti-oxidation coating with a thickness of 35 μm was formed.

[0074] Comparative Example 1

[0075] The 1,1,1-trimethyl-N-2-propylenepropylaminosilane used to prepare the acrylaminosilane-modified epoxy resin in Example 1 was replaced with allyltrimethoxysilane to obtain Comparative Example 1.

[0076] Comparative Example 2

[0077] The 1,1,1-trimethyl-N-2-propylenepropylaminosilane used to prepare the acrylaminosilane-modified epoxy resin in Example 1 was replaced with acrylic acid to obtain Control Example 2.

[0078] Comparative Example 3

[0079] The acrylaminosilane-modified epoxy resin used to prepare the antioxidant coating in Example 1 was replaced with a bisphenol A-type epoxy resin that was not modified by graft copolymerization to obtain Control Example 3.

[0080] The anti-oxidation performance of the silicon aluminum wire samples subjected to the surface anti-oxidation treatment of the above-mentioned Examples 1 to 5 and Comparative Examples 1 to 3 was tested. The test results are shown in Table 1.

[0081] The impact strength test of the sample coating was carried out in accordance with the standard GB / T 1732-2020. After the test, the sample was placed in a 100°C oven for hot air aging for 720 hours, the impact strength was tested again, and the impact strength change rate was calculated.

[0082] Impact strength change rate = [(impact strength before heat aging - impact strength after heat aging) / impact strength before heat aging] * 100%

[0083] Table 1

[0084]

[0085]

[0086] As can be seen from Table 1, the present invention can make the silicon aluminum wire have excellent antioxidant properties by performing surface antioxidant treatment on the silicon aluminum wire, especially the use of acrylaminosilane modified epoxy resin in the antioxidant coating can significantly improve the antioxidant performance of the coating.

[0087] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for treating the surface of a silicon aluminum wire for wire bonding, characterized by: The anti-oxidation coating is evenly coated on the surface of the silicon aluminum wire, and the anti-oxidation coating is formed after curing; The anti-oxidation coating comprises the following components in parts by weight: 100 parts of acrylaminosilane modified epoxy resin, 15-25 parts of silicon nitride powder, 10-20 parts of nano-alumina, 15-25 parts of curing agent, 0-5 parts of curing accelerator, and 0.5-5 parts of defoaming agent; The preparation method of the acrylaminosilane-modified epoxy resin comprises the following steps: firstly, uniformly mixing the epoxy resin and the catalyst, then adding 1,1,1-trimethyl-N-2-propylenepropylaminosilane and an initiator, and heating the mixture for reaction to obtain the acrylaminosilane-modified epoxy resin; the initiator is one or more of azobisisobutyronitrile and azobisisoheptonitrile.

2. The surface antioxidant treatment method according to claim 1, wherein: The curing agent is one or more of aliphatic amine, alicyclic amine, aromatic amine, polyether amine and polyamide.

3. The surface antioxidant treatment method according to claim 1, wherein: The curing accelerator is 2,4,6-tris(dimethylaminomethyl)phenol.

4. The surface antioxidant treatment method according to claim 1, wherein: The defoaming agent is an organosilicon defoaming agent.

5. The surface antioxidant treatment method according to claim 1, wherein: The epoxy resin is bisphenol A epoxy resin.

6. The surface antioxidant treatment method according to claim 1, wherein: The catalyst is one or more of triphenylphosphine and bis(triphenylphosphine)palladium acetate.

7. The surface antioxidant treatment method according to claim 1, wherein: The mass ratio of the epoxy resin, 1,1,1-trimethyl-N-2-propylenepropylaminosilane, initiator and catalyst is (80-100): (15-30): (0.5-1): (0.05-0.1).

8. A silicon aluminum wire for wire bonding prepared according to the surface anti-oxidation treatment method according to any one of claims 1 to 7.

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