CN111744870A - A kind of cleaning method after gold-tin soldering of semiconductor device - Google Patents

Abstract

The invention discloses a cleaning method of a semiconductor device after gold-tin soldering, which comprises the following steps: firstly, soaking a semiconductor device welded by gold and tin in cleaning solution; soaking the semiconductor device in a water tank filled with pure water, and removing the cleaning liquid on the semiconductor device; thirdly, soaking the semiconductor device in alcohol solution to remove pure water on the semiconductor device; fourthly, heating the semiconductor device and removing the alcohol on the semiconductor device. The cleaning method of the invention effectively removes the soldering flux and other pollutants after gold-tin soldering by the mutual matching of the steps (I), (II), (III) and (IV), thereby improving the reliability of the semiconductor device.

Description

A kind of cleaning method after gold-tin soldering of semiconductor device

technical field

The invention relates to the field of semiconductor devices, in particular to a method for cleaning conductor devices after gold-tin soldering.

Background technique

With the gradual application of semiconductor devices in the high-power field, the calorific value of semiconductors is getting higher and higher, and the thermal conductivity of gold-tin soldering can reach 57w/m·K, the highest thermal conductivity among solders. At present, the welding method for mass production of gold-tin welding in the industry is flux + reflow soldering. Flux is an auxiliary material to ensure the smooth progress of the soldering process. It prevents re-oxidation of the surface during soldering, reduces the surface tension of the solder, and improves the soldering performance.

The types of fluxes used in gold-tin soldering mainly include inorganic fluxes, organic fluxes and resin-based fluxes.

Inorganic fluxes contain inorganic acids, mainly hydrochloric acid, hydrofluoric acid, etc. They must be cleaned immediately after use, because any halide remaining on the welded part will cause serious corrosion.

The fluxing effect of organic flux is between that of inorganic flux and resin flux, and it is also an acidic and water-soluble flux. Water-soluble flux containing organic acids, based on lactic acid and citric acid.

The main component of resin-based flux is rosin.

Flux residues on semiconductor devices will have the following problems: reduce conductivity, cause migration or short circuit; non-conductive solids such as intrusion into the contact part of components will cause poor bonding; excessive resin residue, adhesion of dust and debris; Use reliability.

In the existing method, the semiconductor device is put into an ultrasonic cleaning tank with pure water for ultrasonic cleaning, and after the ultrasonic cleaning is completed, the semiconductor device is placed in an oven for baking and drying.

The above cleaning methods have the following problems: 1. During the ultrasonic cleaning process, the energy released by the ultrasonic waves will cause fine cracks between the welding surfaces; 2. After directly cleaning with water, there will be water stains left in the oven.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a cleaning method for semiconductor devices after gold-tin soldering, which has good flux removal effect, no cracks on the welding surface, and no water stains remaining.

In order to solve the above-mentioned technical problems, the present invention provides a method for cleaning semiconductor devices after gold-tin soldering, comprising:

1. Immerse the gold-tin soldered semiconductor device in a cleaning solution, the cleaning solution including at least one of a water-based cleaning solution, a semi-water-based cleaning solution and a hydrocarbon type cleaning solution;

The water-based cleaning solution includes sodium metasilicate, sodium hydroxide, sodium carbonate, ethylene oxide propylene oxide copolymer, carboxymethyl cellulose, fluorine-containing surfactant, complexing agent, and silicone-based defoaming. agent and deionized water;

The semi-aqueous cleaning solution includes tripropylene glycol butyl ether, diethylene glycol butyl ether, methoxymethyl butanol, tetrahydrofurfuryl alcohol, benzyl alcohol, N-methyl diolone, N-ethyl diolone and a base which is one or more of an amine, imide or inorganic base salt, silicate or phosphate;

2. Immerse the semiconductor device in a water tank containing pure water to remove the cleaning solution on the semiconductor device;

3. Soak the semiconductor device in the alcohol solution to remove the pure water on the semiconductor device;

Fourth, heating the semiconductor device to remove the alcohol on the semiconductor device.

As an improvement of the above scheme, in step (1), 1 liter of water-based cleaning solution includes 30-80g sodium metasilicate, 10-30g sodium hydroxide, 20-50g sodium carbonate, 30-80g ethylene oxide propylene oxide copolymerization compound, 3-10g carboxymethyl cellulose, 0-2g fluorosurfactant, 0-5g complexing agent, 0-5g silicone antifoaming agent and balance deionized water.

As an improvement of the above scheme, in step (1), the fluorine-containing surfactant is one or more of sodium perfluorooctanoate, potassium perfluorooctanoate and perfluorooctanoic acid;

The complexing agent is one or more of sodium citrate, EDTA. disodium and EDTA. tetrasodium.

As an improvement of the above scheme, in step (1), the cleaning solution further includes an auxiliary agent, and the auxiliary agent includes at least one of ketones, alcohols, and esters, wherein the ketones are Including at least one of acetone and toluene isobutyl ketone; the alcohols include at least one of ethanol, propanol, butanol; the esters include at least one of ethyl acetate and butyl acetate .

As an improvement of the above scheme, in step (1), the hydrocarbon cleaning agent further includes copper and phosphorus.

As an improvement of the above scheme, in step (1), the temperature of the cleaning solution is 50±10° C., and the soaking time is 1-5 min.

As an improvement of the above scheme, in step (2), the bottom of the water tank is provided with a water inlet and a water outlet, and the water inlet and the water outlet are connected through a pipeline, and the pipeline is provided with a circulating pump and a filter, so The circulating pump draws out the pure water in the water tank from the water outlet, and the extracted pure water enters the water tank from the water inlet through the pipeline, so that the pure water in the water tank forms a circulation.

As an improvement of the above scheme, the semiconductor device is immersed in a water tank for at least two times of water cycle cleaning, and the time for each cycle cleaning is 1 to 3 minutes;

The outflow velocity of pure water in the water tank is 0.5～6m/s, and the inflow velocity is 0.5～5m/s.

As an improvement of the above scheme, in step (2), the electrical conductivity of the pure water is ≦2 μs/cm, and the temperature is 50±10°C.

As an improvement of the above scheme, in step (3), the soaking time of the semiconductor device in the alcohol is 1-5 min.

Implement the present invention, have the following beneficial effects:

The cleaning method of the present invention uses the cleaning agent to remove the flux and other contaminants after gold-tin soldering through the cooperation of steps (1), (2), (3) and (4). Wetting, emulsifying, penetrating, dispersing, solubilizing, etc. of fluorosurfactant, emulsifier (carboxymethyl cellulose), penetrating agent (ethylene oxide propylene oxide copolymer), etc. to dissolve inorganic flux; Compared with the narrow distillation hydrocarbon cleaning agent, the hydrocarbon type cleaning solution of the present invention is composed of chemical compounds, has low toxicity, low odor, good solubility, and can effectively dissolve the organic components in the flux; the semi-aqueous cleaning solution Effectively dissolve the rosin in the resin-based flux; the cleaning solution of the present invention effectively removes the influence of the flux and other pollutants on the semiconductor device, does not damage the gold-tin eutectic and the semiconductor device, and improves the reliability of the semiconductor device; The invention adopts the method of alcohol and heating to remove the pure water of the semiconductor device, thereby avoiding the residual water stains on the semiconductor device, and further improving the reliability of the semiconductor device.

Description of drawings

Fig. 1 is the structural representation of the water tank in step (2) of the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

A method for cleaning semiconductor devices after gold-tin soldering provided by the present invention comprises the following steps:

1. Immerse the gold-tin soldered semiconductor device in a cleaning solution to remove the flux, and the cleaning solution includes at least one of a water-based cleaning solution, a semi-water-based cleaning solution and a hydrocarbon type cleaning solution;

It should be noted that different cleaning solutions are required to clean different types of flux. specific,

Use water-based cleaning solution to clean inorganic flux;

The cleaning of organic flux adopts hydrocarbon type cleaning fluid;

The cleaning resin-based flux adopts a semi-aqueous cleaning solution.

The water-based cleaning solution includes sodium metasilicate, sodium hydroxide, sodium carbonate, ethylene oxide propylene oxide copolymer, carboxymethyl cellulose, fluorine-containing surfactant, complexing agent, and silicone-based defoaming. agent and deionized water.

The hydrocarbon cleaning agent includes one or more of isohydrocarbons with structural formula C _n H _2n +2, normal hydrocarbons with structural formula C _n H _2n+2 , naphthenic hydrocarbons with structural formula C _n H _2n , and aromatic hydrocarbons. a compound.

The semi-aqueous cleaning solution includes tripropylene glycol butyl ether, diethylene glycol butyl ether, methoxymethyl butanol, tetrahydrofurfuryl alcohol, benzyl alcohol, N-methyl diolone, N-ethyl diolone and A base which is one or more of an amine, imide or inorganic base salt, silicate or phosphate.

The water-based cleaning agent of the present invention utilizes the wetting, emulsifying, penetrating, dispersing, and solubilizing of fluorine-containing surfactants, emulsifiers (carboxymethyl cellulose), penetrants (ethylene oxide propylene oxide copolymers), etc. It can dissolve inorganic fluxes without losing gold-tin eutectic and semiconductor devices.

Compared with the narrow distillation hydrocarbon cleaning agent, the hydrocarbon type cleaning liquid of the present invention is composed of a chemical compound, has low toxicity, low odor, good solubility, effectively dissolves the organic components in the flux, and does not lose the gold-tin eutectic at the same time. and semiconductor devices. Among them, isomeric hydrocarbons have branched chains, which are safe and less odorous; aromatic hydrocarbons contain benzene rings and have strong solvency.

The main component of resin-based flux is rosin. The semi-aqueous cleaning solution of the present invention effectively dissolves the rosin in the resin-based flux without losing gold-tin eutectic and semiconductor devices.

Preferably, 1 liter of water-based cleaning solution includes 30-80g sodium metasilicate, 10-30g sodium hydroxide, 20-50g sodium carbonate, 30-80g ethylene oxide propylene oxide copolymer, 3-10g carboxymethyl fiber element, 0-2g of fluorine-containing surfactant, 0-5g of complexing agent, 0-5g of silicone antifoaming agent and the balance of deionized water.

More preferably, 1 liter of water-based cleaning solution includes 40-70g sodium metasilicate, 20-30g sodium hydroxide, 30-40g sodium carbonate, 40-60g ethylene oxide propylene oxide copolymer, 4-7g carboxymethyl Cellulose, 0-2g fluorine-containing surfactant, 1-3g complexing agent, 1-3g silicone antifoaming agent and balance deionized water.

The fluorine-containing surfactant is one or more of sodium perfluorooctanoate, potassium perfluorooctanoate and perfluorooctanoic acid; the complexing agent is one or more of sodium citrate, EDTA.disodium and EDTA.tetrasodium.

The water-based cleaning solution of the present invention improves the osmotic and compatibilizing effects of the water-based cleaning solution by adjusting the contents of the active agent, the emulsifier and the penetrant, thereby improving the cleaning effect of the water-based cleaning solution.

In order to improve the cleaning ability, the hydrocarbon cleaning agent also includes copper and phosphorus. In the present invention, copper and phosphorus are added to the hydrocarbon cleaning agent, and the acid is neutralized at the initial stage of dissolving the flux. The cleaning material is not corroded.

It should be noted that increasing the temperature of the cleaning solution can shorten the cleaning time, but the high temperature of the cleaning solution will affect the reliability of the semiconductor device. In addition, if the semiconductor device is soaked in the cleaning solution for a long time, it will also affect the semiconductor device. device reliability. In order to shorten the cleaning time and improve the cleaning effect and reliability, preferably, the temperature of the cleaning solution is 50±10° C., and the soaking time is 1-5 minutes.

Preferably, the temperature of the water-based cleaning solution is 55±5°C, and the soaking time is 1-3 minutes.

Preferably, the temperature of the hydrocarbon type cleaning solution is 45±5°C, and the soaking time is 2-4 minutes.

Preferably, the temperature of the pure solvent cleaning solution is 50±5°C, and the soaking time is 1-3 minutes.

In order to improve the fluxing ability of the flux, active substances are often added to it, such as zinc chloride, ammonium chloride, organic acids and their halides, organic amines and their halides, hydrazines and their halides, amide urea Wait. Although the fluxing ability is high, the halogen ions are difficult to clean, the ion residue is high, the halogen elements (mainly chlorides) are highly corrosive, and the surfactants are mainly fatty or aromatic non-ionic surfactants , its main function is to reduce the surface tension generated when the solder and the lead pin metal are in contact, enhance the surface wetting force, and enhance the penetration force of the organic acid activator.

In order to remove the above-mentioned substances, the three types of cleaning solutions of the present invention further include auxiliary agents, and the auxiliary agents include at least one of ketones, alcohols, and esters, wherein the ketones include acetone, At least one of toluene isobutyl ketone; the alcohols include at least one of ethanol, propanol and butanol; the esters include at least one of ethyl acetate and butyl acetate.

Preferably, the addition amount of the auxiliary agent is 1% to 10%.

The main function of the ketone substances, alcohol substances and ester substances added in the cleaning solution of the present invention is to dissolve the solid components in the flux to form a uniform solution, and at the same time, it can also clean the oil stains on the metal surface and avoid halogen elements. Corrosion to the device.

In addition, after the gold-tin soldering of semiconductor devices, in addition to the residual flux, there will also be foreign matter in the reflow furnace and solder mask release. These substances will also affect the quality of the semiconductor device, so it should also be removed. The cleaning solution can not only remove the flux, but also remove the foreign matter in the reflow furnace and the release of the solder mask.

2. Immerse the semiconductor device in a water tank filled with pure water;

Since the cleaning solutions of the present invention are all organic substances, the organic or inorganic substances on the substrate of the semiconductor device will be dissolved during the cleaning process, thereby producing some conductors or insulators. These substances will cause the risk of short circuit on the substrate and affect heat dissipation. Therefore, the invention removes the cleaning liquid remaining on the semiconductor device by using pure water.

In order to ensure that the pure water can be fully contacted with the cleaning liquid and quickly remove the cleaning liquid remaining on the semiconductor device, the water tank is provided with a water circulation system and a filter screen, and the pure water in the water tank forms a water circulation through the circulation system, and the filter screen It is used to filter impurities in the sink and maintain the cleaning effect.

Referring to FIG. 1, the bottom of the water tank 1 is provided with a water inlet 11 and a water outlet 12, and the water inlet 11 and the water outlet 12 are connected by a pipeline 13, and the pipeline 13 is provided with a circulating pump 14 and a filter screen 15, The circulating pump 14 extracts the pure water in the water tank 1 from the water outlet 12 , and the extracted pure water enters the water tank 1 from the water inlet 11 through the pipeline 13 , so that the pure water in the water tank 1 forms a circulation.

In order to effectively remove the cleaning solution and ensure that the pure water can be fully contacted with the cleaning solution, further, the semiconductor device is immersed in a water tank for at least two cycles of water cleaning, and the time for each cycle cleaning is 1-3 minutes.

Preferably, the outflow velocity of pure water in the water tank is 0.5-6m/s, and the inflow velocity is 0.5-5m/s. If the outlet water flow is greater than 6m/s and the inlet water flow is greater than 5m/s, the water flow is too large, causing a greater impact on the semiconductor device, causing the semiconductor device to rupture or damage; if the outlet water flow is less than 0.5m/s, the water inlet If the water flow is less than 0.5m/s, the water flow is too small to remove the cleaning liquid and pollutants remaining in the gap.

More preferably, the outflow velocity of pure water in the water tank is 1～3m/s, and the inflow velocity is 1～3m/s.

Raising the temperature of pure water can shorten the cleaning time, but the high temperature of pure water will affect the reliability of semiconductor devices. In order to shorten the cleaning time and improve the cleaning effect and reliability, preferably, the temperature of the pure water is 50±10°C.

The electrical conductivity of the pure water is less than or equal to 2 μs/cm. If the electrical conductivity of the pure water is greater than 2 μs/cm, the purity of the water is insufficient, and the residual cleaning solution cannot be removed, and secondary pollution may also be caused.

3. Soak the semiconductor device in alcohol solution;

In the present invention, the pure water remaining on the semiconductor device is replaced by an alcohol solution.

Since alcohol is an organic substance, if the soaking time is longer than 5 minutes, the organic or inorganic substances on the semiconductor device substrate will be dissolved, resulting in some conductors or insulators. These substances will cause the risk of short circuit on the substrate and affect heat dissipation.

Preferably, the soaking time is 1-5 min.

More preferably, the soaking time is 1-3 min.

The concentration of the alcohol solution is 90-99%.

Fourth, heating the semiconductor device to remove the alcohol on the semiconductor device.

Specifically, the semiconductor device is placed in an oven for baking, and the alcohol remaining on the semiconductor device is evaporated, thereby removing the alcohol on the semiconductor device and avoiding water stains remaining on the semiconductor device.

Preferably, the heating temperature is 80-100° C., and the heating time is 1-5 min.

Since water spots usually contain minerals and metal ions, etc., there is a risk of open circuit or short circuit to semiconductor devices, and at the same time, water spots covering the surface of semiconductor devices will also affect the heat dissipation effect.

The cleaning method of the present invention uses the cleaning agent to remove the soldering flux and other contaminants after gold-tin soldering through the cooperation of steps (1), (2), (3) and (4), thereby improving the reliability of the semiconductor device; In the present invention, the pure water of the semiconductor device is removed by the method of alcohol and heating, so as to avoid residual water stains on the semiconductor device and further improve the reliability of the semiconductor device.

The following will further illustrate the present invention with specific embodiments

Example 1

1. Soak the semiconductor device after gold-tin soldering in the cleaning solution, the temperature of the cleaning solution is 50℃, and the soaking time is 3min;

The cleaning solution includes water-based cleaning solution, and 1 liter of water-based cleaning solution includes 40g sodium metasilicate, 20g sodium hydroxide, 30g sodium carbonate, 40g ethylene oxide propylene oxide copolymer, 5g carboxymethyl cellulose, 1g Fluorine-containing surfactant, 1g complexing agent, 1g silicone antifoaming agent and balance deionized water;

2. Immerse the semiconductor device in a water tank filled with pure water, the temperature of the pure water is 50℃, the soaking time is 2min, the flow rate of the pure water in the water tank is 1m/s, and the flow rate of the inflow water is 1m/s;

3. Soak the semiconductor device in alcohol solution with a concentration of 90%, and the soaking time is 5min;

4. Put the semiconductor device into the oven for heating to remove the alcohol on the semiconductor device.

Example 2

1. Soak the semiconductor device after gold-tin soldering in the cleaning solution, the temperature of the cleaning solution is 60℃, and the soaking time is 1min;

The cleaning solution includes water-based cleaning solution, and 1 liter of water-based cleaning solution includes 40g sodium metasilicate, 20g sodium hydroxide, 30g sodium carbonate, 40g ethylene oxide propylene oxide copolymer, 5g carboxymethyl cellulose, 1g Fluorine-containing surfactant, 1g complexing agent, 1g silicone antifoaming agent and balance deionized water;

2. Immerse the semiconductor device in a water tank filled with pure water, the temperature of the pure water is 50℃, the soaking time is 3min, the flow rate of the pure water in the water tank is 2m/s, and the flow rate of the inflow water is 2m/s;

3. Soak the semiconductor device in alcohol solution with a concentration of 95%, and the soaking time is 4min;

4. Put the semiconductor device into the oven for heating to remove the alcohol on the semiconductor device.

Example 3

1. Soak the semiconductor device after gold-tin soldering in the cleaning solution, the temperature of the cleaning solution is 45℃, and the soaking time is 3min;

The cleaning liquid includes a hydrocarbon cleaning agent, and the hydrocarbon cleaning agent includes an isohydrocarbon compound with a structural formula of C _n H _2n+2 ;

2. Immerse the semiconductor device in a water tank filled with pure water, the temperature of the pure water is 50℃, the soaking time is 3min, the flow rate of the pure water in the water tank is 3m/s, and the flow rate of the inflow water is 3m/s;

3. Immerse the semiconductor device in an alcohol solution with a concentration of 98% for 3 minutes;

4. Put the semiconductor device into the oven for heating to remove the alcohol on the semiconductor device.

Example 4

1. Soak the semiconductor device after gold-tin soldering in the cleaning solution, the temperature of the cleaning solution is 60℃, and the soaking time is 1min;

The cleaning solution includes a hydrocarbon cleaning agent, and the hydrocarbon cleaning agent includes a naphthenic compound with a structural formula of C _n H _2n and copper;

2. Immerse the semiconductor device in a water tank filled with pure water, the temperature of the pure water is 50℃, the soaking time is 2min, the flow rate of the pure water in the water tank is 4m/s, and the flow rate of the inflow water is 4m/s;

3. Soak the semiconductor device in 99% alcohol solution for 1min;

4. Put the semiconductor device into the oven for heating to remove the alcohol on the semiconductor device.

Example 5

1. Soak the semiconductor device after gold-tin soldering in the cleaning solution, the temperature of the cleaning solution is 60℃, and the soaking time is 1min;

The cleaning solution includes a semi-aqueous-based cleaning solution, and the semi-aqueous-based cleaning solution includes tripropylene glycol butyl ether, diethylene glycol butyl ether, methoxymethyl butanol, tetrahydrofurfuryl alcohol, benzyl alcohol, N-methyl pyrocarbon ketones, N-ethylpyridone and amines;

2. Immerse the semiconductor device in a water tank filled with pure water, the temperature of the pure water is 50℃, the soaking time is 2min, the flow rate of the pure water in the water tank is 5m/s, and the flow rate of the inflow water is 5m/s;

3. Soak the semiconductor device in 99% alcohol solution for 1min;

4. Put the semiconductor device into the oven for heating to remove the alcohol on the semiconductor device.

Example 6

1. Soak the semiconductor device after gold-tin soldering in the cleaning solution, the temperature of the cleaning solution is 60℃, and the soaking time is 1min;

The cleaning solution includes a semi-aqueous-based cleaning solution, ethanol and toluene isobutyl ketone, and the semi-aqueous-based cleaning solution includes tripropylene glycol butyl ether, diethylene glycol butyl ether, methoxymethyl butanol, tetrahydrofurfuryl alcohol, benzene Methanol, N-methylpyridone, N-ethylpyridone, imide and inorganic base salts;

2. Immerse the semiconductor device in a water tank filled with pure water, the temperature of the pure water is 50℃, the soaking time is 2min, the flow rate of the pure water in the water tank is 5m/s, and the flow rate of the inflow water is 5m/s;

3. Soak the semiconductor device in 99% alcohol solution for 1min;

4. Put the semiconductor device into the oven for heating to remove the alcohol on the semiconductor device.

Example 7

1. Soak the semiconductor device after gold-tin soldering in the cleaning solution, the temperature of the cleaning solution is 60℃, and the soaking time is 1min;

The cleaning solution includes water-based cleaning solution and ethyl acetate, and 1 liter of water-based cleaning solution includes 40g sodium metasilicate, 20g sodium hydroxide, 30g sodium carbonate, 40g ethylene oxide propylene oxide copolymer, 5g carboxymethyl Cellulose, 1g fluorine-containing surfactant, 1g complexing agent, 1g silicone antifoaming agent and balance deionized water;

2. Immerse the semiconductor device in a water tank filled with pure water, the temperature of the pure water is 50℃, the soaking time is 3min, the flow rate of the pure water in the water tank is 2m/s, and the flow rate of the inflow water is 2m/s;

3. Soak the semiconductor device in alcohol solution with a concentration of 95%, and the soaking time is 4min;

4. Put the semiconductor device into the oven for heating to remove the alcohol on the semiconductor device.

Comparative Example 1

1. Soak the semiconductor device after gold-tin soldering in the cleaning solution, the temperature of the cleaning solution is 60℃, and the soaking time is 1min;

The cleaning solution includes a semi-aqueous-based cleaning solution, and the semi-aqueous-based cleaning solution includes tripropylene glycol butyl ether, diethylene glycol butyl ether, methoxymethyl butanol, tetrahydrofurfuryl alcohol, benzyl alcohol, N-methyl pyrocarbon ketones, N-ethylpyridone and amines;

2. Immerse the semiconductor device in a water tank filled with pure water, the temperature of the pure water is 50℃, the soaking time is 6min, the flow rate of the pure water in the water tank is 8m/s, and the flow rate of the inflow water is 8m/s;

3. Soak the semiconductor device in alcohol solution with a concentration of 99%, and the soaking time is 4min;

4. Put the semiconductor device into the oven for heating to remove the alcohol on the semiconductor device.

Comparative Example 2

1. Soak the semiconductor device after gold-tin soldering in the cleaning solution, the temperature of the cleaning solution is 60℃, and the soaking time is 1min;

The cleaning solution includes water-based cleaning solution and ethyl acetate, and 1 liter of water-based cleaning solution includes 40g sodium metasilicate, 20g sodium hydroxide, 30g sodium carbonate, 40g ethylene oxide propylene oxide copolymer, 5g carboxymethyl Cellulose, 1g fluorine-containing surfactant, 1g complexing agent, 1g silicone antifoaming agent and balance deionized water;

2. Immerse the semiconductor device in a water tank filled with pure water, the soaking time is 1min, the outflow velocity of pure water in the water tank is 0.3m/s, and the inflow velocity is 0.3m/s;

3. Soak the semiconductor device in alcohol solution with a concentration of 75%, and the soaking time is 1min;

4. Put the semiconductor device into the oven for heating to remove the alcohol on the semiconductor device.

Comparative Example 3

1. Immerse the semiconductor device after gold-tin soldering in a water tank filled with pure water, the soaking time is 4min, the outflow velocity of pure water in the water tank is 8m/s, and the inflow velocity is 8m/s;

2. Put the semiconductor device into the oven for heating to remove the pure water on the semiconductor device.

The semiconductor devices cleaned in Examples 1 to 7 and Comparative Examples 1 to 3 were tested for residues, water stains, etc. The results are as follows:

It can be seen from the above results that the same cleaning solution will have the problem of residual cleaning solution at a shorter soaking time and a lower water flow rate, while under a longer soaking time and a higher water flow rate, cracks appear in the semiconductor device In addition, when the alcohol concentration of the soaking is too low and the soaking time is too short, or the semiconductor device is directly dried after cleaning with pure water, the semiconductor device will also have water stains residue; further, if the cleaning solution does not add halogen removal solution , there will also be halogen residues in semiconductor devices.

What is disclosed above is only a preferred embodiment of the present invention, and of course it cannot limit the scope of the rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims (10)

1. a cleaning method after the gold-tin soldering of a semiconductor device is characterized in that, comprising: 1. Immerse the gold-tin soldered semiconductor device in a cleaning solution, the cleaning solution including at least one of a water-based cleaning solution, a semi-water-based cleaning solution and a hydrocarbon type cleaning solution; The water-based cleaning solution includes sodium metasilicate, sodium hydroxide, sodium carbonate, ethylene oxide propylene oxide copolymer, carboxymethyl cellulose, fluorine-containing surfactant, complexing agent, and silicone-based defoaming. agent and deionized water; The semi-aqueous cleaning solution includes tripropylene glycol butyl ether, diethylene glycol butyl ether, methoxymethyl butanol, tetrahydrofurfuryl alcohol, benzyl alcohol, N-methyl diolone, N-ethyl diolone and a base which is one or more of an amine, imide or inorganic base salt, silicate or phosphate; The hydrocarbon cleaning agent includes one or more of isohydrocarbons with structural formula C _n H _2n +2, normal hydrocarbons with structural formula C _n H _2n+2 , naphthenic hydrocarbons with structural formula C _n H _2n , and aromatic hydrocarbons. a compound; 2. Immerse the semiconductor device in a water tank containing pure water to remove the cleaning solution on the semiconductor device; 3. Soak the semiconductor device in the alcohol solution to remove the pure water on the semiconductor device; Fourth, heating the semiconductor device to remove the alcohol on the semiconductor device. 2. The method for cleaning semiconductor devices after gold-tin soldering as claimed in claim 1, wherein in step (1), 1 liter of water-based cleaning solution comprises 30-80g sodium metasilicate, 10-30g sodium hydroxide, 20-50g sodium carbonate, 30-80g ethylene oxide propylene oxide copolymer, 3-10g carboxymethyl cellulose, 0-2g fluorosurfactant, 0-5g complexing agent, 0-5g silicone Antifoam and balance deionized water. 3. The cleaning method after the gold-tin soldering of semiconductor device as claimed in claim 2, is characterized in that, in step (1), described fluorine-containing surfactant is one or more of sodium perfluorooctanoate, potassium perfluorooctanoate and perfluorooctanoic acid. kind; The complexing agent is one or more of sodium citrate, EDTA. disodium and EDTA. tetrasodium. 4. The method for cleaning semiconductor devices after gold-tin soldering according to any one of claims 1 to 3, wherein in step (1), the cleaning solution further comprises an auxiliary agent, and the auxiliary agent comprises ketones At least one of substances, alcohol substances, and ester substances, wherein the ketone substances include at least one of acetone and toluene isobutyl ketone; the alcohol substances include ethanol, propanol, and butanol. At least one; the ester substances include at least one of ethyl acetate and butyl acetate. 5 . The method for cleaning semiconductor devices after gold-tin soldering according to claim 1 , wherein, in step (1), the hydrocarbon cleaning agent further comprises copper and phosphorus. 6 . 6 . The method for cleaning semiconductor devices after gold-tin soldering according to claim 1 , wherein, in step (1), the temperature of the cleaning solution is 50±10° C., and the soaking time is 1-5 min. 7 . 7. The cleaning method after the gold-tin soldering of a semiconductor device as claimed in claim 1, wherein in step (2), the bottom of the water tank is provided with a water inlet and a water outlet, and the water inlet and the water outlet pass through The pipeline is connected with a circulating pump and a filter screen. The circulating pump draws out the pure water in the water tank from the water outlet, and the extracted pure water enters the water tank from the water inlet through the pipeline, so that the pure water in the water tank is Water forms a cycle. 8. The method for cleaning semiconductor devices after gold-tin soldering according to claim 7, wherein the semiconductor device is immersed in a water tank for at least two water cycle cleaning, and the time for each cycle cleaning is 1 to 3 minutes; The outflow velocity of pure water in the water tank is 0.5～6m/s, and the inflow velocity is 0.5～5m/s. 9 . The method for cleaning semiconductor devices after gold-tin soldering according to claim 1 , wherein in step (2), the electrical conductivity of the pure water is ≦2 μs/cm, and the temperature is 50±10° C. 10 . 10 . The method for cleaning semiconductor devices after gold-tin soldering according to claim 1 , wherein, in step (3), the soaking time of the semiconductor devices in alcohol is 1-5 min. 11 .

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