CN111590235A - Low-dielectric-loss high-reliability soldering paste and preparation method thereof - Google Patents

Abstract

The invention discloses a soldering paste with low dielectric loss and high reliability and a preparation method thereof, and the technical scheme is as follows: 85.4-91.6 wt% of solder alloy powder, 8.4-14.6 wt% of soldering flux, wherein the tin powder comprises 2.5-4.1 wt% of silver, 0.5-2.6 wt% of copper, 6.5-8.7 wt% of indium, 3.1-4.7 wt% of zinc, 0.11-0.25 wt% of molybdenum, 0.09-0.19 wt% of vanadium, 0.08-0.21 wt% of lutetium and the balance of tin, the soldering flux comprises 35.4-42.6 wt% of rosin, 8.4-14.6 wt% of organic acid, 1.8-4.6 wt% of organic amine, 3.3-6.1 wt% of thixotropic agent, 3.5-6.8 wt% of thermosetting resin, 1.4-3.2 wt% of antioxidant and the balance of organic solvent, the soldering flux is composed of 48-56 wt% of cyanate ester resin and 44-52 wt% of epoxy resin, the solder paste does not have residual corrosion residue after being used for a solder paste, and the soldering paste is prepared by using the soldering flux paste The soldering paste with low dielectric loss, high surface insulation resistance after soldering and high reliability is suitable for being used in 5G related application scenes.

Description

Low-dielectric-loss high-reliability soldering paste and preparation method thereof

[ technical field ] A method for producing a semiconductor device

The invention belongs to the technical field of welding materials, and particularly relates to a low-dielectric-loss high-reliability soldering paste and a preparation method thereof.

[ background of the invention ]

At present, the solder paste used by 5G electronic communication products of high-end electronic information enterprises represented by hua as well as zhongxing communication mainly depends on import for the following reasons: the radioactive isotope elements such as Bi, Pb, Co and the like are added into the soldering tin alloy in the current market, alpha decay easily occurs in the soldering tin alloy, alpha particles can be continuously released in a semiconductor device, and then the semiconductor device is caused to generate a single event effect, the integrity of a 5G signal is affected by loss, and data loss, function interruption and the like of electronic equipment are damaged; on the other hand, magnetic materials such as Fe, Co, Ni and Nd are added into the soldering tin alloy, and the magnetic permeability of the magnetic materials changes nonlinearly along with the change of a magnetic field, so that hysteresis characteristics occur, and finally, two or more signals generate strong interference signals, so that a communication system is greatly influenced; the active agents added to the flux are halogen, amine and amino compounds, which are liable to cause excessive corrosion after soldering, form corrosive residues on the circuit board, have a great influence on the substrate, and usually need to be cleaned to reduce the corrosivity. The dielectric loss of the solder paste after curing is increased due to the above reasons, and the high-frequency 5G electronic product requires lower dielectric loss after curing of the solder paste so as to improve the transmission speed and the signal strength of signals.

Therefore, there is an urgent need in the art to develop a low-loss and high-reliability solder paste to meet the application conditions in a 5G scenario.

[ summary of the invention ]

The invention aims to solve the technical problem of high dielectric loss of the existing soldering paste, provides the soldering paste with low dielectric loss and high reliability, does not have corrosive residues on a circuit board after soldering, and prepares the soldering paste with low residue, low dielectric loss, high surface insulation resistance after soldering and high reliability, which is suitable for being used in 5G related application scenes.

Another object of the present invention is to provide a method for preparing a solder paste with low dielectric loss and high reliability.

The invention relates to a low dielectric loss high reliability soldering paste, which comprises the following components by weight: 85.4-91.6 wt% of solder alloy powder and 8.4-14.6 wt% of soldering flux;

the solder alloy powder consists of the following components: 2.5-4.1 wt% silver, 0.5-2.6 wt% copper, 6.5-8.7 wt% indium, 3.1-4.7 wt% zinc, 0.11-0.25 wt% molybdenum, 0.09-0.19 wt% vanadium, 0.08-0.21 wt% lutetium, and the balance tin;

the soldering flux consists of the following components: 35.4-42.6 wt% of rosin, 8.4-14.6 wt% of organic acid, 1.8-4.6 wt% of organic amine, 3.3-6.1 wt% of thixotropic agent, 3.5-6.8 wt% of thermosetting resin, 1.4-3.2 wt% of antioxidant and the balance of organic solvent; the thermosetting resin consists of 48-56 wt% of cyanate ester resin and 44-52 wt% of epoxy resin.

Preferably, the cyanate ester resin is one or more of bisphenol a cyanate ester, bisphenol F cyanate ester, bisphenol M cyanate ester, and phenolic cyanate ester.

The application discloses a low dielectric loss high reliability solder paste, which comprises 85.4-91.6 wt% of solder alloy powder and 8.4-14.6 wt% of soldering flux, wherein the solder alloy powder comprises tin, silver, copper, indium, zinc, molybdenum, vanadium and lutetium, radioactive isotope elements such as Bi, Pb, Co and the like are not added into the solder alloy powder so as to reduce signal interference caused by decay, magnetic materials such as Fe, Co, Ni, Nd and the like are not added, the signal interference caused by material nonlinearity can be reduced, a small amount of rare earth elements such as molybdenum, vanadium and lutetium are added into the solder alloy powder, the solder alloy powder has good heat conduction, electric conduction and ductility, extremely strong activity has excellent improvement effect on electric heating performance and oxidation resistance in the solder alloy powder, the dielectric loss can be reduced by extremely low resistivity, the solder paste comprises rosin, organic acid, organic amine, a thixotropic agent, thermosetting resin, an antioxidant and an organic solvent, the organic acid used is halide-free active agent, the acid is weak and the action is soft, the corrosion to the substrate is small, the residues after welding are reduced, the cleaning is not needed, the rosin is matched at high temperature to clean the surface of the metal for decontamination, in addition, the organic amine is added to adjust the pH value of the soldering flux, the organic amine and the organic acid are subjected to acid-base compound treatment to play a role of a corrosion inhibitor, thermosetting resin is also added to the soldering flux and comprises cyanate ester resin and epoxy resin, the cyanate ester resin has excellent dielectric property and also has high temperature resistance and excellent bonding property, the epoxy resin is utilized to carry out copolymerization modification on the cyanate ester, the modified matrix has excellent dielectric property, so that the soldering paste has lower dielectric loss after being cured, simultaneously, the air can be isolated, the surface tension of soldering tin is reduced, the tin wetting capacity and the diffusion capacity of the metal surface are improved, and the reoxida, the soldering flux and the solder alloy are subjected to an inert chemical reaction at normal temperature, the performance stability of the soldering paste is not affected, and the activation temperature of the soldering flux is adapted to the melting point of the solder alloy powder. The wettability, the oxidation resistance and the welding performance of the soldering paste are greatly improved, corrosive residues do not exist on a circuit board after welding, the prepared soldering paste has low residue, low dielectric loss, high surface insulation resistance after welding and high reliability, and is suitable for being used in 5G related application scenes.

Preferably, the cyanate ester resin is one or more of bisphenol a cyanate ester, bisphenol F cyanate ester, bisphenol M cyanate ester, and phenolic cyanate ester. Cyanate is a high-performance resin matrix, a triazine network formed after curing has excellent mechanical properties, high glass transition temperature (Tg ═ 260C), and extremely low dielectric constant and dielectric loss, and the mechanical properties and dielectric properties of the solder paste can be improved through a cyanate/epoxy resin system added in the soldering flux, so that the prepared solder paste has the characteristic of low dielectric loss.

Preferably, the epoxy resin is one or a combination of more of alicyclic epoxy resin, bisphenol A epoxy resin, phenol-aralkyl epoxy resin and glycidyl amine epoxy resin. The cyanate ester resin is subjected to copolymerization modification through the epoxy resin, and the dielectric property of the system is reduced after modification.

Preferably, the organic acid is a combination of two or more of succinic acid, adipic acid, sebacic acid and stearic acid. This application uses organic acid as the activator, has avoided using these materials of halogen, amine and amino compound to easily cause excessive corruption after welding, and is very big to the base plate influence, need reduce corrosivity through wasing, use organic acid to reduce the degree of corrosion, this application is a halide-free activator, need not wash after the welding, not only can practice thrift cleaning equipment and cleaning solvent's input, can also reduce the pollution that the emission of waste gas and waste water brought the environment, cooperation rosin clean metal surface scrubbing under the high temperature.

Preferably, the organic amine is one or a combination of more of triethanolamine, diethylenetriamine and triethylene tetramine. Organic amines themselves contain an amino group, NH: has activity, and the organic amine is added to promote the welding effect. The organic acid and the organic amine are mixed to generate neutralization reaction, and a neutralization product is generated. The neutralization product is unstable and can be rapidly decomposed at the welding temperature to regenerate the organic acid and the organic amine, so that the original activity of the organic acid can be ensured, and after the welding is finished, the residual organic acid can be neutralized by the organic amine, so that the acidity of the residue is reduced, and the corrosion is reduced. Therefore, after the organic amine is added, the acidity of the soldering flux can be adjusted, the soldering point can be bright, and the corrosion after soldering is reduced to the minimum under the condition of not reducing the activity of the soldering flux.

Preferably, the organic solvent is diethylene glycol dimethyl ether and diethylene glycol octyl ether which are compounded according to the weight ratio of 1-3: 1-2. The diethylene glycol dimethyl ether and the diethylene glycol octyl ether used in the application are high-boiling-point solvents, high in volatility, capable of reducing residues after welding, and capable of preventing collapse and controlling viscosity.

Preferably, the thixotropic agent is octadecyl stearic acid amide and polyamide modified hydrogenated castor oil according to the weight ratio of 1: 1-3 compounding. The viscosity and the printing performance of the soldering paste are mainly adjusted, the soldering paste is endowed with certain thixotropy, the viscosity of the soldering paste is increased under an unstressed state, the inherent shape is kept, the soldering paste is prevented from collapsing, the effects of preventing phenomena such as trailing, adhesion and collapse in printing are achieved, and the thixotropic agent is obtained by compounding octadecyl stearic acid amide and polyamide modified hydrogenated castor oil and has better effect than a single thixotropic agent.

Preferably, the rosin is disproportionated rosin and water white rosin in a weight ratio of 1-2: 2-3 compounding. The preferable rosin is AT04 disproportionated rosin produced by Guitian chemical company, is a modified rosin obtained by eliminating easily oxidized conjugated double bonds on the rosin, has higher inoxidizability, does not show activity when playing the role of a protective film AT normal temperature, but is activated AT high temperature of reflow soldering, quickly removes the oxide film on the surfaces of solder and parent metal in a short time, and forms a protective film for preventing metal from reoxidizing on the surface of the solder, thereby being beneficial to inhibiting the generation of the oxide film on the surface of the solder during the heating period of reflow soldering, and leading the solder paste to still keep good soldering activity under continuous high-temperature baking.

Preferably, the antioxidant is any one or a combination of several of antioxidant 565, antioxidant 1330, antioxidant 1425 and antioxidant 1010. The function of the solder paste is to prevent the solder flux from oxidative deterioration, improve the oxidation resistance of the solder paste, inhibit the oxidation of the solder paste and reduce the occurrence of pillow effect.

A preparation method of a soldering paste with low dielectric loss and high reliability is characterized by comprising the following steps:

s1, weighing the components according to the weight percentage for later use;

s2, adding an organic solvent into a container, heating to 140 ℃ below zero, adding rosin, adding thermosetting resin after dissolving, and stirring until the thermosetting resin is completely dissolved;

s3, keeping the temperature at 140 ℃ and adding a thixotropic agent and stirring until the thixotropic agent is completely dissolved;

s4, cooling the temperature to 60-80 ℃, adding an antioxidant, an organic acid and organic amine, and stirring for 40-60 minutes;

s5, grinding the mixture by a grinder at the rotating speed of 4000-5000 r/min until the particle size is less than 20 microns to obtain the soldering flux;

and S6, adding the soldering flux and the solder alloy powder into the solder paste stirrer, and mixing and stirring for 40-60 minutes to obtain the solder paste.

Compared with the prior art, the invention has the following advantages:

the application discloses a low dielectric loss high reliability soldering paste, which comprises 85.4-91.6 wt% of solder alloy powder and 8.4-14.6 wt% of soldering flux, wherein the solder alloy powder comprises tin, silver, copper, indium, zinc, molybdenum, vanadium and lutetium, no radioactive isotope elements such as Bi, Pb, Co and the like are added into the solder alloy to reduce signal interference caused by decay, no magnetic materials such as Fe, Co, Ni, Nd and the like are added to reduce signal interference caused by material nonlinearity, a small amount of rare earth elements such as molybdenum, vanadium and lutetium are added into the soldering paste, so that the soldering paste has good heat conduction, electric conduction and ductility, extremely strong activation performance has excellent effect on improving the electric heating performance in the soldering paste alloy powder, and the medium loss can be reduced by extremely low resistivity, the soldering flux comprises rosin, organic acid, organic amine, thixotropic agent, thermosetting resin, antioxidant and organic solvent, the organic acid used is halide-free active agent, the acid is weak and the action is soft, the corrosivity brought to the base material is small, the residues after welding is reduced, the cleaning is not needed, the rosin is matched at high temperature to clean the surface of the metal for decontamination, in addition, the organic amine is added to adjust the pH value of the soldering flux, the organic amine and the organic acid are subjected to acid-base compounding treatment to play a role of a corrosion inhibitor, thermosetting resin is added to the soldering flux and comprises cyanate ester resin and epoxy resin, the cyanate ester resin has excellent dielectric property and also has high temperature resistance and excellent bonding property, the epoxy resin is utilized to carry out copolymerization modification on the cyanate ester, the modified matrix has excellent dielectric property, so that the soldering paste has low dielectric loss after being cured, the soldering flux and the soldering alloy are subjected to inert chemical reaction under the normal temperature condition, and the performance stability of the soldering paste is not, after soldering, no corrosive residue exists on the circuit board, and the prepared soldering paste has low residue, low dielectric loss, high surface insulation resistance after soldering and high reliability, and is suitable for being used in 5G related application scenes.

The preparation method of the soldering paste with low dielectric loss and high reliability, provided by the invention, has the advantages of simple and convenient process and mild reaction, and is suitable for large-scale continuous production.

[ detailed description ] embodiments

The following is a detailed description of the present invention:

the specific technical scheme of the invention is described by combining specific embodiments 1-6:

example 1:

a low dielectric loss high reliability solder paste comprises the following components by weight, 88.9 wt% of solder alloy powder and 11.1 wt% of soldering flux, wherein the component proportion of the solder alloy powder is shown in Table 2, the component proportion of the soldering flux is shown in Table 3, and the preparation method comprises the following steps:

weighing the components according to the weight percentages in the tables 2 and 3 for later use; firstly, adding a solvent into a container, heating to 120 ℃, adding rosin, stirring until the rosin is completely dissolved, adding thermosetting resin, keeping the temperature at 120 ℃, adding a thixotropic agent into the container, keeping the temperature and stirring until the thixotropic agent is completely dissolved; reducing the temperature to 70 ℃, adding an antioxidant, an organic acid and organic amine, keeping the temperature and stirring for 45 minutes; grinding the mixture by a grinder at the rotating speed of 4000r/min until the particle size is less than 20 microns to obtain the soldering flux; adding soldering flux and solder alloy components into a solder paste stirrer, mixing and stirring for 60 minutes, and refrigerating to obtain the low-dielectric-loss high-reliability solder paste.

Example 2:

a low dielectric loss high reliability solder paste comprises the following components by weight, 90.1 wt% of solder alloy powder and 9.9 wt% of soldering flux, wherein the component proportion of the solder alloy powder is shown in Table 2, the component proportion of the soldering flux is shown in Table 3, and the preparation method comprises the following steps:

weighing the components according to the weight percentages in the tables 2 and 3 for later use; firstly, adding a solvent into a container, heating to 125 ℃, adding rosin, stirring until the rosin is completely dissolved, adding thermosetting resin, keeping the temperature at 125 ℃, adding a thixotropic agent into the container, keeping the temperature and stirring until the thixotropic agent is completely dissolved; reducing the temperature to 65 ℃, adding an antioxidant, an organic acid and organic amine, keeping the temperature and stirring for 30 minutes; grinding the mixture by a grinder at the rotating speed of 4500r/min until the particle size is less than 20 microns to obtain the soldering flux; adding soldering flux and solder alloy components into a solder paste stirrer, mixing and stirring for 50 minutes, and refrigerating to obtain the low-dielectric-loss high-reliability solder paste.

Example 3:

a low dielectric loss high reliability solder paste comprises the following components by weight, 85.4 wt% of solder alloy powder and 14.6 wt% of soldering flux, wherein the component proportion of the solder alloy powder is shown in Table 2, the component proportion of the soldering flux is shown in Table 3, and the preparation method comprises the following steps:

weighing the components according to the weight percentages in the tables 2 and 3 for later use; firstly, adding a solvent into a container, heating to 130 ℃, adding rosin, stirring until the rosin is completely dissolved, adding thermosetting resin, keeping the temperature at 130 ℃, adding a thixotropic agent into the container, keeping the temperature and stirring until the thixotropic agent is completely dissolved; reducing the temperature to 80 ℃, adding an antioxidant, an organic acid and organic amine, keeping the temperature and stirring for 50 minutes; grinding the mixture by a grinder at the rotating speed of 4000r/min until the particle size is less than 20 microns to obtain the soldering flux; adding soldering flux and solder alloy components into a solder paste stirrer, mixing and stirring for 40 minutes, and refrigerating to obtain the low-dielectric-loss high-reliability solder paste.

Example 4:

a low dielectric loss high reliability solder paste comprises the following components by weight, 86.8 wt% of solder alloy powder and 13.2 wt% of soldering flux, wherein the component proportion of the solder alloy powder is shown in Table 2, the component proportion of the soldering flux is shown in Table 3, and the preparation method comprises the following steps:

weighing the components according to the weight percentages in the tables 2 and 3 for later use; firstly, adding a solvent into a container, heating to 135 ℃, adding rosin, stirring until the rosin is completely dissolved, adding thermosetting resin, keeping the temperature at 135 ℃, adding a thixotropic agent into the container, keeping the temperature and stirring until the thixotropic agent is completely dissolved; reducing the temperature to 75 ℃, adding an antioxidant, an organic acid and organic amine, keeping the temperature and stirring for 30 minutes; grinding the mixture by a grinder at the rotating speed of 5000r/min until the particle size is less than 20 microns to obtain the soldering flux; adding soldering flux and solder alloy components into a solder paste stirrer, mixing and stirring for 55 minutes, and refrigerating to obtain the low-dielectric-loss high-reliability solder paste.

Example 5:

a low dielectric loss high reliability solder paste comprises the following components by weight, 91.6 wt% of solder alloy powder and 8.4 wt% of soldering flux, wherein the component proportion of the solder alloy powder is shown in Table 2, the component proportion of the soldering flux is shown in Table 3, and the preparation method comprises the following steps:

weighing the components according to the weight percentages in the tables 2 and 3 for later use; firstly, adding a solvent into a container, heating to 125 ℃, adding rosin, stirring until the rosin is completely dissolved, adding thermosetting resin, keeping the temperature at 125 ℃, adding a thixotropic agent into the container, keeping the temperature and stirring until the thixotropic agent is completely dissolved; reducing the temperature to 80 ℃, adding an antioxidant, an organic acid and organic amine, keeping the temperature and stirring for 60 minutes; grinding the mixture by a grinder at the rotating speed of 5000r/min until the particle size is less than 20 microns to obtain the soldering flux; adding soldering flux and solder alloy components into a solder paste stirrer, mixing and stirring for 60 minutes, and refrigerating to obtain the low-dielectric-loss high-reliability solder paste.

Example 6:

a low dielectric loss high reliability solder paste comprises the following components by weight, 87.3 wt% of solder alloy powder and 12.7 wt% of soldering flux, wherein the component proportion of the solder alloy powder is shown in Table 2, the component proportion of the soldering flux is shown in Table 3, and the preparation method comprises the following steps:

weighing the components according to the weight percentages in the tables 2 and 3 for later use; firstly, adding a solvent into a container, heating to 125 ℃, adding rosin, stirring until the rosin is completely dissolved, adding thermosetting resin, keeping the temperature at 125 ℃, adding a thixotropic agent into the container, keeping the temperature and stirring until the thixotropic agent is completely dissolved; reducing the temperature to 75 ℃, adding an antioxidant, an organic acid and organic amine, keeping the temperature and stirring for 30 minutes; grinding the mixture by a grinder at the rotating speed of 5000r/min until the particle size is less than 20 microns to obtain the soldering flux; adding soldering flux and solder alloy components into a solder paste stirrer, mixing and stirring for 40 minutes, and refrigerating to obtain the low-dielectric-loss high-reliability solder paste.

Table 1: the solder paste of the embodiment 1-6 comprises the following components in parts by weight:

components

Example 1

Example 2

Example 3

Example 4

Example 5

Example 6

Solder alloy powder

88.90％

90.10％

85.40％

86.80％

91.60％

87.30％

Soldering flux

11.10％

9.90％

14.60％

13.20％

8.40％

12.70％

Table 2: the solder alloy powder of the embodiments 1-6 comprises the following components in parts by weight:

components

Example 1

Example 2

Example 3

Example 4

Example 5

Example 6

Tin (Sn)

82.79％

83.42％

83.78％

83.86％

82.50％

83.33％

Silver (Ag)

3.20％

4.10％

2.50％

3.50％

2.80％

3.80％

Copper (Cu)

1.80％

2.10％

0.80％

0.50％

2.40％

1.20％

Indium (In)

8.40％

6.80％

8.70％

7.20％

7.60％

6.50％

Zinc

3.40％

3.10％

3.80％

4.50％

4.20％

4.70％

Molybdenum (Mo)

0.13％

0.15％

0.21％

0.11％

0.25％

0.18％

Vanadium oxide

0.19％

0.12％

0.09％

0.15％

0.17％

0.13％

Lutetium (Lu)

0.09％

0.21％

0.12％

0.18％

0.08％

0.16％

Table 3: the soldering flux of the embodiment 1-6 comprises the following components in parts by weight:

the low dielectric loss and high reliability solder pastes prepared in the examples 1-6 and the commercial lead-free solder paste of the comparative example are subjected to performance tests, and the test results are shown in the following table 4:

table 4: test results of examples 1 to 6 and comparative example

From the test data in table 4, it can be seen that the solder paste has high surface insulation resistance and low dielectric loss compared with the commercially available lead-free solder paste, and meanwhile, the halogen content is low, the copper mirror test, the corrosion resistance and the wettability all meet the requirements, the viscosity of the solder paste meets the industrial standard of 170 Pa.s and 250 Pa.s, the expansion rate meets the industrial standard of 80-90%, and no corrosive residue exists on the circuit board after soldering, so that the solder paste with low residue, low dielectric loss, high surface insulation resistance after soldering and high reliability can be prepared by the method, and the method is suitable for being used in 5G related application scenes. The application discloses a low dielectric loss high reliability soldering paste, which comprises 85.4-91.6 wt% of solder alloy powder and 8.4-14.6 wt% of soldering flux, wherein the solder alloy powder comprises tin, silver, copper, indium, zinc, molybdenum, vanadium and lutetium, no radioactive isotope elements such as Bi, Pb, Co and the like are added into the solder alloy to reduce signal interference caused by decay, no magnetic materials such as Fe, Co, Ni, Nd and the like are added to reduce signal interference caused by material nonlinearity, a small amount of rare earth elements such as molybdenum, vanadium and lutetium are added into the soldering paste, so that the soldering paste has good heat conduction, electric conduction and ductility, extremely strong activation performance has excellent effect on improving the electric heating performance in the soldering paste alloy powder, and the medium loss can be reduced by extremely low resistivity, the soldering flux comprises rosin, organic acid, organic amine, thixotropic agent, thermosetting resin, antioxidant and organic solvent, the organic acid used is halide-free active agent, the acid is weak and the action is soft, the corrosivity brought to the base material is small, the residues after welding is reduced, the cleaning is not needed, the rosin is matched at high temperature to clean the surface of the metal for decontamination, in addition, the organic amine is added to adjust the pH value of the soldering flux, the organic amine and the organic acid are subjected to acid-base compounding treatment to play a role of a corrosion inhibitor, thermosetting resin is added to the soldering flux and comprises cyanate ester resin and epoxy resin, the cyanate ester resin has excellent dielectric property and also has high temperature resistance and excellent bonding property, the epoxy resin is utilized to carry out copolymerization modification on the cyanate ester, the modified matrix has excellent dielectric property, so that the soldering paste has low dielectric loss after being cured, the soldering flux and the soldering alloy are subjected to inert chemical reaction under the normal temperature condition, and the performance stability of the soldering paste is not, after soldering, no corrosive residue exists on the circuit board, and the prepared soldering paste has low residue, low dielectric loss, high surface insulation resistance after soldering and high reliability, and is suitable for being used in 5G related application scenes.

Claims (10)

1. A low dielectric loss high reliability solder paste is characterized in that: the composition consists of the following components: 85.4-91.6 wt% of solder alloy powder and 8.4-14.6 wt% of soldering flux;

the solder alloy powder consists of the following components: 2.5-4.1 wt% silver, 0.5-2.6 wt% copper, 6.5-8.7 wt% indium, 3.1-4.7 wt% zinc, 0.11-0.25 wt% molybdenum, 0.09-0.19 wt% vanadium, 0.08-0.21 wt% lutetium, and the balance tin;

the soldering flux consists of the following components: 35.4-42.6 wt% of rosin, 8.4-14.6 wt% of organic acid, 1.8-4.6 wt% of organic amine, 3.3-6.1 wt% of thixotropic agent, 3.5-6.8 wt% of thermosetting resin, 1.4-3.2 wt% of antioxidant and the balance of organic solvent; the thermosetting resin consists of 48-56 wt% of cyanate ester resin and 44-52 wt% of epoxy resin.

2. The low dielectric loss high reliability solder paste of claim 1, wherein: the cyanate resin is one or a combination of bisphenol A cyanate, bisphenol F cyanate, bisphenol M cyanate and phenolic cyanate.

3. The low dielectric loss high reliability solder paste of claim 1, wherein: the epoxy resin is one or a combination of more of alicyclic epoxy resin, bisphenol A type epoxy resin, phenol-aralkyl epoxy resin and glycidyl amine type epoxy resin.

4. The low dielectric loss high reliability solder paste of claim 1, wherein: the organic acid is two or a plurality of combinations of succinic acid, adipic acid, sebacic acid and stearic acid.

5. The low dielectric loss high reliability solder paste of claim 1, wherein: the organic amine is one or a combination of more of triethanolamine, diethylenetriamine and triethylene tetramine.

6. The low dielectric loss high reliability solder paste of claim 1, wherein: the organic solvent is formed by compounding diethylene glycol dimethyl ether and diethylene glycol octyl ether according to the weight ratio of 1-3: 1-2.

7. The low dielectric loss high reliability solder paste of claim 1, wherein: the thixotropic agent is prepared from octadecyl stearic acid amide and polyamide modified hydrogenated castor oil according to the weight ratio of 1: 1-3 compounding.

8. The low dielectric loss high reliability solder paste of claim 1, wherein: the rosin is disproportionated rosin and water white rosin in a weight ratio of 1-2: 2-3 compounding.

9. The low dielectric loss high reliability solder paste of claim 1, wherein: the antioxidant is any one or combination of antioxidant 565, antioxidant 1330, antioxidant 1425 and antioxidant 1010.

10. A method for preparing a low dielectric loss high reliability solder paste according to any one of claims 1-9, characterized by the steps of:

s1, weighing the components according to the weight percentage for later use;

s2, adding an organic solvent into a container, heating to 140 ℃ below zero, adding rosin, adding thermosetting resin after dissolving, and stirring until the thermosetting resin is completely dissolved;

s3, keeping the temperature at 140 ℃ and adding a thixotropic agent and stirring until the thixotropic agent is completely dissolved;

s4, cooling the temperature to 60-80 ℃, adding an antioxidant, an organic acid and organic amine, and stirring for 40-60 minutes;

s5, grinding the mixture by a grinder at the rotating speed of 4000-5000 r/min until the particle size is less than 20 microns to obtain the soldering flux;

and S6, adding the soldering flux and the solder alloy powder into the solder paste stirrer, and mixing and stirring for 40-60 minutes to obtain the solder paste.