CN-121402883-B - Welding method and device of vacuum welding furnace

Abstract

The invention relates to the technical field of chip packaging, and provides a welding method and device of a vacuum welding furnace, wherein the welding method and device comprise the steps of vacuumizing the vacuum welding furnace, reducing the pressure of the vacuum welding furnace to micro negative pressure, setting first heating power P1, heating the first heating power P1 to a first preheating temperature T1, setting preheating heat preservation time, determining heating rate according to a heating rate formula, heating the second heating power P 2 and heating rate to a second preheating temperature T2, heating the third heating power P 3 and heating rate to a third preheating temperature T3, heating the fourth heating power P 4 to peak temperature, synchronously filling nitrogen to the set positive pressure P Positive pressure , determining full-melting heat preservation time according to a full-melting heat preservation formula, obtaining fifth heating power P 5 for heating, quickly vacuumizing, obtaining foam-removing heat preservation time according to a foam-removing time formula, and performing cooling steps by the vacuum welding furnace. No bubble is generated in the solder, and the welding quality is high.

Inventors

• ZHANG YANZHONG
• ZHAO YONGXIAN
• DENG YAN
• Wen Aixin

Assignees

• 北京仝志伟业科技有限公司

Dates

Publication Date

20260505

Application Date

20251220

Claims (4)

1. 1. A welding method of a vacuum welding furnace, comprising: Vacuumizing the vacuum welding furnace, and reducing the pressure of the vacuum welding furnace to a micro negative pressure which is 80-100kPa; Setting a first heating power P 1 according to a power calculation formula, heating to a first preheating temperature T1 by using the first heating power P 1 according to the type of solder, and setting preheating heat preservation time according to the thickness of the solder, wherein the power calculation formula is as follows: First heating power P 1 = (C w ·m w + C f ·m f + C s ·m s )·V 1 /eta C w is specific heat capacity of a workpiece, m w is mass of the workpiece, eta is heat efficiency, C s is specific heat capacity of solder, m s is mass of solder, C s is specific heat capacity of a vacuum welding furnace, and m f is effective mass of the vacuum welding furnace; Determining a heating rate according to a heating rate formula, wherein the second heating power P 2 and the heating rate are heated to a second preheating temperature T2, the third heating power P 3 and the heating rate are heated to a third preheating temperature T3, the second heating power P 2 is 1.18-1.2 times of the first heating power P 1 , the third heating power P 3 is 1.08-1.1 times of the second heating power P 2 , and the heating rate formula is as follows: V=3.0-5×delta, delta is the solder thickness value in mm; The fourth heating power P 4 is heated to the peak temperature, nitrogen is synchronously filled to the set positive pressure P Positive pressure according to a full-melting positive pressure formula, the full-melting heat preservation time is determined according to a full-melting heat preservation formula, and the full-melting positive pressure formula is as follows: P Positive pressure =0.1+2×δ, δ, solder thickness in mm, the formula of total melting heat preservation is t Thermal insulation =30+100×δ, δ, solder thickness in mm; Obtaining fifth heating power P 5 for heating according to a foam discharging formula, rapidly vacuumizing, obtaining foam discharging and heat preserving time according to a foam discharging and heat preserving time formula, and discharging foam and preserving heat according to the foam discharging and heat preserving time, wherein the foam discharging formula comprises the following steps: P 5 = P 4 × (P Positive pressure / P Vacuum ) 0.3 ; P Vacuum is vacuum stage pressure in MPa, P Positive pressure ： is positive pressure in MPa, and the foam discharging time formula is as follows: t Bubble removing device =15+50×δ, δ: solder thickness value in mm; The vacuum welding furnace performs the cooling step.
2. 2. The welding method of a vacuum welding furnace according to claim 1, wherein the first preheating temperature T 1 =T Melting point -Δt,T Melting point is a solder melting point temperature, Δt=50 to 80 ℃.
3. 3. The method according to claim 1, wherein the fourth heating power P 4 = K×P 3 is a solder correction coefficient.
4. 4. The welding method of a vacuum welding furnace according to claim 1, wherein the vacuum welding furnace performs the cooling step specifically as follows: The fifth heating power P 5 is reduced to the sixth heating power P 6 , and the temperature is cooled to T Melting point -10 ℃; The sixth heating power P 6 is reduced to the seventh heating power P 7 , and cooled to 145-155 ℃; The seventh heating power P 7 is reduced to eighth heating power P 8 , and the temperature is cooled to 75-85 ℃; And gradually backfilling nitrogen to normal temperature and normal pressure, and taking out the workpiece.

Description

Welding method and device of vacuum welding furnace Technical Field The invention relates to the technical field of semiconductors, in particular to a welding method and device of a vacuum welding furnace. Background The vacuum welding equipment in the prior art is professional equipment for welding workpieces, and the structure of the vacuum welding equipment mainly comprises a controller, a sealable cavity, a vacuumizing device, a heating plate, a cooling device and the like. The heating plate is positioned in the sealable cavity and is used for placing workpieces. The heating device and the cooling device are respectively corresponding to the lower parts of the heating plates and are respectively connected with the controller, and the heating or cooling process of the heating plates is completed under the regulation and control of the controller. The vacuumizing device is arranged on the outer side of the sealable cavity, and performs vacuumizing treatment on the sealable cavity, so that the welding process is performed in an anaerobic state, the welding quality is ensured, the cavity rate inside welding is reduced, and the reliability of a weldment is improved. The solder in the prior art is easy to generate bubbles inside and has low welding quality. Disclosure of Invention The invention provides a welding method of a vacuum welding furnace, which is used for solving the problems that in the prior art, solder is easy to generate bubbles inside and the welding quality is low. A welding method of a vacuum welding furnace, comprising: vacuumizing the vacuum welding furnace, and reducing the pressure of the vacuum welding furnace to micro negative pressure; Setting a first heating power P 1 according to a power calculation formula, heating to a first preheating temperature T1 according to the type of the solder by using the first heating power P 1, and setting preheating heat preservation time according to the thickness of the solder; Determining a heating rate according to a heating rate formula, heating the second heating power P 2 and the heating rate to a second preheating temperature T2, and heating the third heating power P 3 and the heating rate to a third preheating temperature T3; The fourth heating power P 4 is heated to the peak temperature, nitrogen is synchronously filled to the set positive pressure P Positive pressure according to the full-melting positive pressure formula, and the full-melting heat preservation time is determined according to the full-melting heat preservation formula; Obtaining fifth heating power P 5 for heating according to a foam discharging formula, rapidly vacuumizing, obtaining foam discharging and heat preserving time according to a foam discharging and heat preserving time formula, and discharging and preserving heat according to the foam discharging and heat preserving time; The vacuum welding furnace performs the cooling step. According to the welding method of the vacuum welding furnace, the first preheating temperature T 1=T Melting point -Δt,T Melting point is the melting point temperature of the welding flux, and delta t=50-80 ℃. According to the welding method of the vacuum welding furnace, the power calculation formula comprises the following steps: First heating power P 1 = (Cw·mw + Cf·mf + Cs·ms)·V1/eta C w is specific heat capacity of a workpiece, m w is mass of the workpiece, eta is heat efficiency, C s is specific heat capacity of solder, m s is mass of solder, C s is specific heat capacity of a vacuum welding furnace, and m f is effective mass of the vacuum welding furnace. According to the welding method of the vacuum welding furnace, the second heating power P 2 is 1.18-1.2 times of the first heating power P 1, and the third heating power P 3 is 1.08-1.1 times of the second heating power P 2. According to the welding method of the vacuum welding furnace, the fourth heating power P 4= K×P3 and the welding flux correction coefficient are adopted. According to the welding method of the vacuum welding furnace, the foam discharging formula comprises the following steps: P5 = P4 × (P Positive pressure / P Vacuum )0.3; P Vacuum vacuum stage pressure, P Positive pressure ： positive pressure. According to the welding method of the vacuum welding furnace, the full-melt positive pressure formula comprises the following steps: P Positive pressure = 0.1 + 2 x delta, delta: solder thickness value. According to the welding method of the vacuum welding furnace, the temperature rising rate formula is as follows: V=3.0-5×δ, δ: solder thickness value. According to the welding method of the vacuum welding furnace, the vacuum welding furnace carries out the cooling steps specifically as follows: The fifth heating power P 5 is reduced to the sixth heating power P 6, and the temperature is cooled to T Melting point -10 ℃; The sixth heating power P6 is reduced to the seventh heating power P7, and the temperature is cooled to 145-155 ℃; The seventh heating power