An efficient cleaning liquid composition for IGBT modules

Abstract

An efficient cleaning liquid composition for IGBT modules, which is composed of the following raw materials: a novel polyether, an alkaline substance, an organic solvent, a corrosion inhibitor and a penetrant. The present invention defines the raw material composition of the efficient cleaning liquid composition and adds a self-made novel polyether. The hydrophobic chain in this polyether is polymerized from methyl methacrylate, so it contains a large number of ester groups. The ester groups have good affinity for rosin substances in the flux and can firmly "grab" pollutants. The other end is a polyoxyethylene ether with hydrophilicity, which can pull pollutants into the water body in an aqueous solution and separate them from the surface of the device to achieve the cleaning effect.

Description

Technical Field

[0001] The present invention belongs to the field of IGBT module preparation, and particularly relates to an efficient cleaning liquid composition for IGBT modules, which is used for cleaning the flux during the manufacturing process of IGBT modules. Background Art

[0002] An IGBT module is a modular semiconductor product formed by bridging and packaging an IGBT (insulated gate bipolar transistor chip) and an FWD (freewheeling diode chip) through a specific circuit, and is usually applied to devices such as frequency converters and UPS uninterruptible power supplies. IGBT modules have the characteristics of energy conservation, convenient installation and maintenance, and stable heat dissipation; most of the modular products sold on the current market are of this type, and generally speaking, IGBT also refers to an IGBT module; with the promotion of concepts such as energy conservation and environmental protection, such products will be more and more common in the market.

[0003] An IGBT is a device composed of a MOSFET and a bipolar transistor in combination. Its input terminal is a MOSFET, and its output terminal is a PNP transistor. It combines the advantages of these two devices. It has both the advantages of small driving power and fast switching speed of MOSFET devices, and the advantages of low saturation voltage and large capacity of bipolar devices. Its frequency characteristics are between those of MOSFETs and power transistors, and it can operate normally within a frequency range of dozens of kHz, and has been more and more widely used in modern power electronics technology, occupying a dominant position in high-power applications at higher frequencies. However, since the IGBT module has a MOSFET structure, the gate of the IGBT is electrically isolated from the emitter through an oxide film. Since this oxide film is very thin, its breakdown voltage generally reaches 20 - 30V; therefore, gate breakdown caused by static electricity is one of the common causes of IGBT failure. In order to reduce the defect rate of IGBT modules, it is necessary to clean the IGBT modules during the production process.

[0004] Currently, the cleaning liquids on the market are mainly divided into water-based cleaning liquids and solvent-based cleaning liquids. Among them, water-based cleaning liquids have a long service life, are safe during use, and have little harm to the human body. However, most water-based cleaning liquids use strong acids and strong bases as additives, and have poor material compatibility, which easily causes the copper substrate of the IGBT to corrode and change color. Therefore, solvent-based cleaning liquids are more commonly used for IGBT cleaning; Solvent-based cleaning liquids use the principle of similar solubility to dissolve pollutants in organic solvents and clean them. However, solvent-based cleaning liquids generally have the disadvantages of easy volatilization, low flash point, and easy accidents. Therefore, solvent-based cleaning liquids are not the best choice for IGBT module cleaning. Developing a water-based cleaning liquid with good material compatibility for IGBT module cleaning has broad market prospects. Summary of the Invention

[0005] The object of the present invention is to overcome the disadvantages of the prior art and provide an efficient cleaning liquid composition for IGBT modules.

[0006] The present invention adopts the following technical solutions:

[0007] An efficient cleaning liquid composition for IGBT modules, in terms of mass percentage, its raw material composition is as follows:

[0008]

[0009] The novel polyether has the following structure:

[0010]

[0011] Furthermore, the alkaline substance is one or more of triethanolamine, triisopropanolamine, and triethylenediamine.

[0012] Furthermore, the organic solvent is one or more of N-methylpyrrolidone, tetrahydrofurfuryl alcohol, cyclohexane, dipropylene glycol methyl ethyl ether, propylene glycol phenyl ether, and dipropylene glycol methyl ether.

[0013] Furthermore, the corrosion inhibitor is one or more of methylbenzotriazole, sodium mercaptobenzothiazole, and benzotriazole.

[0014] Furthermore, the penetrant is one or more of JFC-E, JFC-2G, and JFC-SF.

[0015] Furthermore, its preparation process is as follows: First, add the organic solvent to a stirring kettle, and then successively add the alkaline substance, novel polyether, corrosion inhibitor, and penetrant. During the feeding process, after each component is fed, it needs to be stirred until it becomes clear before adding the next component; after all components are added, continue to stir for 5 - 15 minutes to obtain the efficient cleaning liquid composition.

[0016] Furthermore, its usage method is: When in use, the efficient cleaning liquid composition is diluted with DI water to 10 - 20 wt%.

[0017] Furthermore, the preparation process of the novel polyether includes the following steps:

[0018] Step 1, successively add 1 mol of 4-bromo-1-phenyl-1-butanol, 2 mol of sodium iodide, 50 mol of methyl methacrylate, and 0.5 mol of triethylenediamine to a reactor. Under a nitrogen atmosphere, irradiate with UVB light with a wavelength of 315 - 280 nm for 60 minutes, and after recrystallization with cyclohexane, C 10 H 13 O-PMMA-I can be obtained;

[0019] Step 2: Add 1 mol of C prepared in Step 1 10 H 13 O-PMMA-I and 0.05 mol of K 3 [Co(CN) 6 ·6Cu(NO 3 ) 2 ·5H 2 O·0.5ZnCl 2 into the reactor, dehydrate at 150 °C for 60 min. Under a nitrogen atmosphere, add 0.5 mol of ethylene oxide, keep the temperature at 150 °C, and the pressure less than 0.3 Mpa. When the reaction pressure drops significantly and the temperature rises sharply, continue to add 90 mol of ethylene oxide, keep the temperature at 140 - 160 °C, and the pressure less than 0.3 MPa; until the pressure in the reactor no longer decreases, continue to keep the temperature for 30 min, and remove the unreacted ethylene oxide under reduced pressure to obtain the new polyether PEO-C 10 H 13 O-PMMA-I.

[0020] As can be seen from the above description of the present invention, compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] First, the present invention defines the raw material composition of the high-efficiency cleaning liquid composition and adds a self-made new polyether. The hydrophobic chain in this polyether is polymerized from methyl methacrylate, so it contains a large number of ester groups. The ester groups have good affinity for rosin substances in the soldering flux and can firmly "grab" pollutants. The other end is a polyoxyethylene ether with hydrophilicity, which can pull pollutants into the water body in an aqueous solution and separate them from the surface of the device to achieve the cleaning effect;

[0022] Second, by adding the self-made new polyether, the present invention improves the cleaning performance of the cleaning liquid. Therefore, on the basis of meeting the existing cleaning requirements, strong alkaline components such as sodium hydroxide, potassium hydroxide, and ethanolamine can be discarded, and mild alkaline substances such as triethanolamine and triisopropanolamine can be used instead; the base material of IGBT is copper, and sodium hydroxide and potassium hydroxide will corrode copper, and primary amines such as ethanolamine will have a strong complexing effect with copper. However, substances such as triethanolamine, triisopropanolamine, and triethylenediamine have weak alkalinity and will not corrode the copper plate. Under the action of corrosion inhibitors such as methylbenzotriazole, the complexing effect on copper can be alleviated, so the copper plate will not change color; this makes the cleaning liquid materials disclosed in the present invention have a wider compatibility;

[0023] Thirdly, for the high-efficiency cleaning liquid composition prepared by the present invention for IGBT modules, its preparation method only requires simple physical mixing without involving chemical reactions. The preparation process is simple and safe. And when it is used, it only needs to be diluted with DI water, which can be carried out at the client side. Therefore, it can be in the form of a concentrated solution during the production, sales, and transportation processes, reducing the storage and transportation costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a synthetic route diagram of a novel polyether;

[0025] Figure 2 It is a picture of an IGBT module after being cleaned with the high-efficiency cleaning liquid composition defined in the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The present invention will be further described below through specific embodiments.

[0027] A high-efficiency cleaning liquid composition for IGBT modules, in terms of mass percentage, its raw material composition is as follows:

[0028]

[0029]

[0030] Its preparation process is as follows: First, add an organic solvent to a stirring kettle, and sequentially add an alkaline substance, a novel polyether, a corrosion inhibitor, and a penetrant at a rotation speed of 100 r / min. During the feeding process, after each component is fed, it needs to be stirred until it becomes clear before adding the next component; after all components are added, continue to stir for 10 minutes, and then carry out packaging to obtain the high-efficiency cleaning liquid composition.

[0031] Its usage method is: When in use, the high-efficiency cleaning liquid composition is diluted with DI water to 10 - 20 wt%.

[0032] Specifically, the structure of the novel polyether is as follows:

[0033]

[0034] Its synthetic route refers to Figure 1 ;

[0035] The specific preparation method includes the following steps:

[0036] Step 1: Add 1 mol of 4-bromo-1-phenyl-1-butanol, 2 mol of sodium iodide, 50 mol of methyl methacrylate, and 0.5 mol of triethylenediamine into the reactor in sequence. Under a nitrogen atmosphere, irradiate with UVB light with a wavelength of 315 - 280 nm for 60 min. After recrystallization with cyclohexane, C 10 H 13 O-PMMA-I can be obtained;

[0037] Step 2: Add 1 mol of C 10 H 13 O-PMMA-I prepared in Step 1 and 0.05 mol of K 3 [Co(CN) 6 ·6Cu(NO 3 ) 2 ·5H 2 O·0.5ZnCl 2 into the reactor, dehydrate at 150 °C for 60 min. Under a nitrogen atmosphere, add 0.5 mol of ethylene oxide, keep the temperature at 150 °C, and the pressure less than 0.3 Mpa. When the reaction pressure drops significantly and the temperature rises sharply, continue to add 90 mol of ethylene oxide, keep the temperature at 140 - 160 °C, and the pressure less than 0.3 MPa; until the pressure in the reactor no longer decreases, continue to keep the temperature for 30 min, and remove the unreacted ethylene oxide under reduced pressure to obtain the novel polyether PEO-C 10 H 13 O-PMMA-I.

[0038] The basic substance is one or several of triethanolamine, triisopropanolamine, and triethylenediamine.

[0039] The organic solvent is one or several of N-methylpyrrolidone, tetrahydrofurfuryl alcohol, cyclohexane, dipropylene glycol methyl ethyl ether, propylene glycol phenyl ether, and dipropylene glycol methyl ether.

[0040] The corrosion inhibitor is methylbenzotriazole (TTA), sodium mercaptobenzothiazole (MBT-Na), and benzotriazole (BTA).

[0041] The penetrant is one or several of JFC-E, JFC-2G, and JFC-SF.

[0042] Examples

[0043] Each example and comparative example are prepared with reference to the parameters in Table 1

[0044] Table 1 Parameter compositions of each example and comparative example

[0045]

[0046]

[0047] From the above table, it can be seen that the cleaning liquid composition prepared by the present invention has stable properties, good compatibility, and no problems such as precipitation and condensation.

[0048] Cleaning test

[0049] The cleaning liquid compositions prepared in Examples 1-5 and Comparative Examples 1-5 were used to conduct cleaning tests on IGBT modules.

[0050] Test scheme: First, dilute the cleaning liquid composition according to the ratio to make the mass fraction of the stock solution 20%. Then add it to an offline pneumatic cleaning machine, heat it to 50°C, put the IGBT module in for cleaning for 10 minutes. After cleaning, rinse it 3 times with DI water at room temperature for 5 minutes each time; after rinsing, dry it with hot air at 80°C; observe the cleaning effect and material compatibility under an optical microscope magnified 40 times. For specific results, refer to Table 2.

[0051] Table 2 Cleaning test results of each example and comparative example

[0052]

[0053]

[0054] From Table 2, it can be seen that the cleaning liquid composition prepared by the present invention can clean the IGBT module well and has good material compatibility with the substrate and solder joints. From Comparative Example 1 and Comparative Example 5, it can be seen that the lack of the novel polyether or alkaline substance will lead to a decline in cleaning performance and cannot meet the cleanliness requirements; from Comparative Example 2, it can be seen that the stronger alkaline primary amine can meet the cleaning requirements, but it will affect the copper substrate; from Comparative Example 3, it can be seen that the stronger alkaline NaOH will not only corrode the copper but also corrode the solder joints, resulting in insecure welding; from Comparative Example 4, it can be seen that without the corrosion inhibitor, even the weakly alkaline triethanolamine will affect the substrate.

[0055] In summary, the high-efficiency cleaning liquid composition for IGBT modules prepared by the present invention has a good cleaning effect on IGBT modules and broad material compatibility. It contains a self-made novel polyether, and the hydrophobic chain in this polyether is polymerized from methyl methacrylate, so it contains a large number of ester groups. The ester groups have good affinity for the rosin substances in the flux and can firmly "grab" the pollutants. The other end is a polyoxyethylene ether with hydrophilicity, which can pull the pollutants into the water body in the aqueous solution and separate them from the device surface to achieve the cleaning effect.

[0056] The above are only the preferred embodiments of the present invention, and thus cannot limit the scope of implementation of the present invention. That is, equivalent changes and modifications made according to the scope of the patent application of the present invention and the content of the specification should still fall within the scope covered by the patent of the present invention.

Claims

1. An efficient cleaning liquid composition for IGBT modules, characterized in that: In terms of mass percentage, its raw material composition is as follows: The polyether structure is as follows: The alkaline substance is one or more of triethanolamine, triisopropanolamine, and triethylenediamine; The organic solvent is one or more of N-methylpyrrolidone, tetrahydrofurfuryl alcohol, dipropylene glycol methyl ethyl ether, propylene glycol phenyl ether, and dipropylene glycol methyl ether; The corrosion inhibitor is one or more of methylbenzotriazole, sodium mercaptobenzothiazole, and benzotriazole.

2. The efficient cleaning liquid composition for IGBT modules according to claim 1, characterized in that: The penetrant is one or more of JFC-E, JFC-2G, and JFC-SF.

3. The efficient cleaning liquid composition for IGBT modules according to claim 1, characterized in that: Its preparation process is as follows: First, add the organic solvent to a stirring kettle, and then sequentially add the alkaline substance, polyether, corrosion inhibitor, and penetrant. During the feeding process, after each component is fed, it needs to be stirred until it is in a clear state before adding the next component; after all components are added, continue to stir for 5-15 minutes to obtain the efficient cleaning liquid composition for IGBT modules.

4. The efficient cleaning liquid composition for IGBT modules according to claim 1, characterized in that: The preparation process of the polyether includes the following steps: Step 1: Add 1 mol of 4-bromo-1-phenyl-1-butanol, 2 mol of sodium iodide, 50 mol of methyl methacrylate, and 0.5 mol of triethylenediamine into the reactor in sequence. Under a nitrogen atmosphere, irradiate with UVB light with a wavelength of 315 - 280 nm for 60 min, and after recrystallization with cyclohexane, C can be obtained. 10 H 13 O-PMMA-I; Step 2: Add 1 mol of C prepared in Step 1 10 H 13 O-PMMA-I and 0.05 mol of K 3 [Co(CN) 6 ·6Cu(NO 3 ) 2 ·5H 2 O·0.5ZnCl 2 into a reactor, dehydrate at 150 °C for 60 min. Under a nitrogen atmosphere, add 0.5 mol of ethylene oxide, maintain the temperature at 150 °C, and keep the pressure less than 0.3 Mpa. When the reaction pressure drops significantly and the temperature rises sharply, continue to add 90 mol of ethylene oxide, maintain the temperature at 140 - 160 °C, and keep the pressure less than 0.3 MPa; until the pressure in the reactor no longer decreases, continue to maintain the temperature for 30 min, and remove the unreacted ethylene oxide under reduced pressure to obtain polyether PEO-C 10 H 13 O-PMMA-I.

5. The usage method of the efficient cleaning liquid composition for IGBT modules according to claim 1, characterized in that: When in use, the efficient cleaning liquid composition is diluted with DI water to 10-20 wt%.

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