A kind of preparation facilities of precise welded ball
Technical field
The present invention relates to the preparation of advanced used for electronic packaging precise welded ball, belong to a kind of preparation facilities of precise welded ball, same the present invention also can be used for the preparation of low-melting-point metal or its alloy spherical particle or powder.
Background technology
At present, along with of the development of terminal consumption electronic product, force the integrated circuit encapsulation technology to densification, miniaturization, integrated direction evolution towards " light, thin, short, little " and multifunction direction.Along with integrated the improving constantly of integrated circuit, the Electronic Packaging form also develops to BGA (Ball Grid Array), CSP face array package forms such as (Chip Scale Package) from four limit pins (QFP) gradually, in BGA and CSP packaging technology, use precise welded ball to substitute pin, realize being electrically connected and mechanical connection between circuit substrate and the chip.Precise welded ball is the solder alloy bead of diameter range between 0.2~0.76mm.Above-mentioned advanced encapsulation is all very strict to the requirement of the aspects such as diameter error, sphericity and surface quality of precise welded ball, thereby traditional metallic particles and powder preparation technology have been proposed new challenge.At present, the precise welded ball preparation method of main flow is-chopping remelting process, spray-on process and drip etc. on the market.The chopping remelting process at first is processed into solder alloy by machining modes such as wire drawing-shearing or paillon foil-punching presses the small alloy unit of homogeneous quality, then the alloy unit that processes being put into a certain high temperature nodularization solution remelting is shaped, under capillary effect, alloy unit finally condenses into the sphere that needs.The major advantage of said method is that the production technology controllability is good, the yield rate height of product.But it has significant disadvantages simultaneously: production process is various, and the equipment needed thereby investment is big, and introduces various impurity easily in the process of repeatedly processing.Spray-on process is to extend from the conventional powder technology of preparing, be characterized in that production capacity is strong, but process controllability is poor, and product percent of pass is low.
Summary of the invention
It is good to the purpose of this invention is to provide a kind of controllability, and equipment investment is few, production efficiency height, constant product quality, the preparation facilities of the precise welded ball that performance is good.
For achieving the above object, the present invention takes following design:
A kind of preparation facilities of precise welded ball, it comprises melting kettle, tundish, solidify cavity, piezoelectric vibration exciter, gatherer, bottom in melting kettle is provided with the quartz micropores filter plate, be connected carrier pipe at melting kettle with tundish, tundish is provided with piezoelectric vibration exciter, be connected with the ultra micro nozzle in the bottom of tundish, the vibration head of this piezoelectric vibration exciter enters the top that is arranged on the ultra micro nozzle in the tundish, be provided with in the bottom of tundish and solidify cavity, in solidifying cavity, add solidification liquid is arranged, this top of solidifying cavity is the opening shape, between upper end of solidifying cavity and tundish bottom, be provided with the injection closed cavity, be connected with ball valve in the bottom of solidifying cavity, the bottom of this ball valve is connected with gatherer.
It also includes pressure difference transmitter the preparation facilities of this precise welded ball; two sensors of control pressure difference transmitter work; one is arranged in the melting kettle by line; another is arranged on by line and sprays in the closed cavity; the loam cake of melting kettle is provided with the pressure protect gas appendix that enters in the melting kettle; on this appendix, be connected with magnetic valve; this magnetic valve is connected with pressure difference transmitter by control line; be connected with flow pump on carrier pipe, this flow pump is connected with pressure difference transmitter by control line.
The lateral wall of described melting kettle is provided with heater, is provided with the heating sheath at the lateral wall of tundish, is provided with the heating sheath that formation temperature gradient from top to bottom distributes at the lateral wall that solidifies cavity.
Be connected with tracheae on the sidewall of tundish, this tracheae is connected with vacuum valve respectively with protection gas appendix and is connected: be connected with another tracheae on the sidewall that sprays closed cavity, this tracheae is connected with another vacuum valve respectively with another protection gas appendix and is connected; Two vacuum valves are connected with vavuum pump by tracheae.
Upper side wall at gatherer is connected with the solidification liquid carrier pipe, and the other end of this carrier pipe is connected with hydraulic motor, and this hydraulic motor is connected with the solidification liquid storage tank; Penetrated an overflow pipe at the downside wall that solidifies cavity, this overflow pipe is along the madial wall setting of solidifying cavity, and the top of this overflow pipe is a little less than the top of solidifying cavity; Be connected with another overflow pipe at the diapire that sprays closed cavity, the lower end of these two overflow pipes is communicated with the back and is connected with the liquid back pipe of condenser, and this condenser and solidification liquid storage tank are connected to form the circulatory system.
Described ultra micro nozzle is single hole or porous, and the diameter range of its ultra micro nozzle is between 0.050~5.000mm, and draw ratio is 1: 2~6; The vibration frequency range of piezoelectric vibration exciter is between 1~20kHz.
The structure of the preparation facilities of precise welded ball of the present invention mainly comprises the melt purifying device in melting kettle, the melting kettle, melt flows control system, tundish, vibrator, ultra micro nozzle, is frozen into die cavity, vacuum inert gas shielding system and the coagulating agent circulatory system is formed.Its main feature is that melting kettle has melt purifying device and melt flow control device.Melt purifying device is the quartz micropores filter plate, guarantees that with the pressure reduction between pressure difference transmitter control smelting furnace and tundish melt flow is constant simultaneously, has improved the controllability of technology, and greatly reduces the oxide inclusions in the alloy and the content of other impurity; Tundish peripheral hardware electrical heat tracing sheath is provided with protective gas at sidewall of the furnace body and imports and exports, and the container bottom center is inlaid with single hole or jet rose, and the number of jet rose can reach 50 more than at most.Nozzle diameter is between 0.050~5.00mm, and the draw ratio of nozzle is between 2~6; Vibrator is installed in the top of tundish, the diameter of lower end vibration head is far longer than nozzle diameter, and greater than the edge of distributed diameter of jet rose, to guarantee that vibration head covers fully and will vibrate homogeneous radiation around jet rose, and, make metal jet under the surface wave effect that vibration produces, be fractured into symmetrical liquid drop at metal jet surface generation surface wave.
In implementation process of the present invention, the nozzle lower end is provided with special-purpose coagulation forming equipment, and coagulation forming equipment is provided with the segmentation heater outward, can control the thermograde and the setting rate of process of setting.Overflow pipe is housed in solidifying cavity in addition, can makes the liquid level of coagulating agent in the whole production flow process, keep invariable, and can regulate the height of overflow pipe according to the variation of technology.Solidification liquid is mainly the adjustable silicone oil of viscosity, and adds the mineral wet goods of the activating agent, mixed rosin and the adjusting coagulating agent density that increase metal surface tension in silicone oil.Molten drop is coagulation forming air-isolation fully in solidification liquid, reduce the degree of oxidation, the solidification liquid that has certain viscosity simultaneously can make the speed of molten drop decline slow, increased the time of metal freezing, thereby can control the process of setting of molten drop by the thermograde of control control solidification liquid, reach best institutional framework.Keep liquid state in the time that molten drop is relatively grown in addition in the certain viscosity solidification liquid, can overcome the gravity of part metals on the one hand by resistance, and have time enough to make molten drop under capillary effect, be returned to the spheroidal state of surface tension minimum, thereby being solidified, molten drop forms the very high solder globules of out of roundness.
In melting and tundish, all adopt nitrogen protection among the present invention, in condensation chamber, adopt nitrogen to add the protection atmosphere of hydrogen.All adopt the protective gas protection in melting to the whole process of coagulation forming, make the oxygen content of the product that finally obtains very low, the metal surface has enough surface smoothnesses.
The present invention has the following advantages:
1, relative machining remelting processing, the present invention can all finish from the metal or alloy melting to grain forming by a technological process, has improved production efficiency greatly, and its equipment is simple relatively, and equipment investment is very little.
2, each technological parameter independence is good in the method for the present invention, process controllability is strong, control the surface wave on metal jet surface by temperature control melting, pressure control flow velocity to the exciting condition, thereby control the uniformity of metal jet fracture, it is very little to influence each other between each technological parameter.Therefore the distribution granularity of the metallic particles that produces is very narrow.
3, molten drop is solidified in solidification liquid with liquid form, offset the influence of gravity by resistance and comprehensively always using of buoyancy that solidification liquid viscosity produces to coagulation forming, give full play to capillary effect, obtain the extraordinary solder globules of sphericity.Simultaneously by the thermograde of control solidification liquid and setting rate that viscosity can be controlled molten drop to obtain the solder globules of structure property the best.
Description of drawings
Fig. 1 is the preparation facilities structural representation of precise welded ball of the present invention
Fig. 2 is a ultra micro nozzle arrangements schematic diagram among Fig. 1
Fig. 3 is the grading curve schematic diagram
The specific embodiment
Referring to Fig. 1, shown in Figure 2:
A kind of preparation facilities of precise welded ball, it comprises melting kettle 3, tundish 24, solidify cavity 15, piezoelectric vibration exciter 23, gatherer 9, bottom in melting kettle 3 is provided with quartz micropores filter plate 2, be connected carrier pipe 13 at melting kettle 3 with tundish 24, tundish 24 is provided with piezoelectric vibration exciter 23, be connected with ultra micro nozzle 16 in the bottom of tundish 24, the vibration head 22 of this piezoelectric vibration exciter 23 enters the top that is arranged on ultra micro nozzle 16 in the tundish, be provided with in the bottom of tundish 24 and solidify cavity 15, in solidifying cavity, add solidification liquid 36 is arranged, this top of solidifying cavity 15 is the opening shape, between upper end of solidifying cavity 15 and tundish 24 bottoms, be provided with and spray closed cavity 20, be connected with ball valve 10 in the bottom of solidifying cavity 15, the bottom of this ball valve 10 is connected with gatherer 9.Be connected with ball valve 39 in this gatherer lower end, close ball valve 10, open ball valve 39, the solder globules in the gatherer 9 can be exported; Close ball valve 39, open ball valve 10, can in solidifying cavity 15, carry solidification liquid 36 by carrier pipe 38; Solder globules can enter in the gatherer 9 by the ball valve of opening 10.
It also includes pressure difference transmitter 12 preparation facilities of this precise welded ball; adopt TY-1151DP/GP series transmitter; two sensors 8 of control pressure difference transmitter work; 19; one is arranged in the melting kettle 3 by line; another is arranged on by line and sprays in the closed cavity 20; pressure in the melting kettle 3 is 200KPa; spraying in the closed cavity 20 is 101KPa (1 atmospheric pressure); the loam cake 4 of melting kettle 3 is provided with the protection tracheae 7 that enters in the melting kettle 3; be connected with magnetic valve 5 on the protection tracheae 7; magnetic valve 5 is connected with pressure difference transmitter 12 by control line; be connected with flow pump 18 on carrier pipe 13, this flow pump 18 is connected with pressure difference transmitter 12 by control line 17.
The lateral wall of melting kettle 3 is provided with heater, lateral wall at tundish 24 is provided with heating sheath 21, thermocouple 11 is installed in solidifying cavity 15, be used to detect, control the thermograde of solidification liquid 36, be provided with the heating sheath 14 of formation temperature gradient distribution from top to bottom at the lateral wall that solidifies cavity 15.
Be connected with tracheae 26 on the sidewall of tundish 24, this tracheae 26 is connected with vacuum valve 28 respectively with protection gas appendix 27 and is connected; Be connected with another tracheae 26 on the sidewall that sprays closed cavity 20, this tracheae 26 is connected with another vacuum valve 29 respectively with another protection gas appendix 32 and is connected; Two vacuum valves 28,29 connect 31 by tracheae and vavuum pump and connect.
Upper side wall at gatherer 9 is connected with solidification liquid carrier pipe 38, and the other end of this carrier pipe 38 is connected with hydraulic motor 40, and this hydraulic motor 40 is connected with solidification liquid storage tank 37; Penetrated an overflow pipe 33 at the downside wall that solidifies cavity 15, this overflow pipe 33 is along the madial wall setting of solidifying cavity, and the top of this overflow pipe 33 is a little less than the top of solidifying cavity 15; Be connected with another overflow pipe 30 at the diapire that sprays closed cavity 20, the lower end of these two overflow pipes is communicated with the back and is connected with the liquid back pipe 34 of condenser 35, and this condenser 35 is connected to form the circulatory system with solidification liquid storage tank 37.
Described ultra micro nozzle is single hole 41 or porous, and the diameter range of its ultra micro nozzle is between 0.050~5.000mm, and draw ratio is 1: 2~6; The vibration frequency range of piezoelectric vibration exciter is between 1~20kHz.
Table 1 particle diameter distribution table:
Particle diameter (μ m) |
Differential distributes |
Cumulative distribution |
Particle diameter (μ m) |
Differential distributes |
Cumulative distribution |
Particle diameter (μ m) |
Differential distributes |
Cumulative distribution |
150.0 |
4.85 |
4.85 |
266.3 |
6.47 |
14.46 |
472.7 |
0.41 |
99.58 |
157.3 |
0.00 |
4.85 |
279.3 |
43.22 |
57.67 |
495.9 |
0.00 |
99.58 |
165.1 |
0.00 |
4.85 |
293.0 |
27.95 |
85.62 |
520.2 |
0.13 |
99.71 |
173.1 |
0.26 |
5.11 |
307.4 |
1.34 |
86.96 |
545.7 |
0.01 |
99.72 |
181.6 |
0.28 |
5.39 |
322.4 |
0.00 |
86.96 |
572.4 |
0.14 |
99.86 |
190.5 |
0.56 |
5.96 |
338.2 |
0.54 |
87.50 |
600.4 |
0.00 |
99.86 |
199.9 |
0.29 |
6.24 |
354.8 |
0.38 |
87.88 |
629.8 |
0.14 |
100 |
209.6 |
0.14 |
6.38 |
372.2 |
1.40 |
89.28 |
660.7 |
0.00 |
100 |
219.9 |
0.11 |
6.49 |
390.4 |
6.67 |
95.95 |
693.1 |
0.00 |
100 |
230.7 |
0.30 |
6.79 |
409.5 |
2.64 |
98.59 |
727.0 |
0.00 |
100 |
242.0 |
0.14 |
6.93 |
429.6 |
0.57 |
99.16 |
762.6 |
0.00 |
100 |
253.8 |
1.06 |
6.99 |
450.6 |
0.01 |
99.17 |
800.0 |
0.00 |
100 |
Referring to Fig. 1, shown in Figure 2:
A kind of preparation facilities of implementing the precise welded ball of right said method, it comprises melting kettle 3, tundish 24, solidify cavity 15, piezoelectric vibration exciter 23, gatherer 9, bottom in melting kettle 3 is provided with quartz micropores filter plate 2, be connected carrier pipe 13 at melting kettle 3 with tundish 24, tundish 24 is provided with piezoelectric vibration exciter 23, be connected with ultra micro nozzle 16 in the bottom of tundish 24, the vibration head 22 of this piezoelectric vibration exciter 23 enters the top that is arranged on ultra micro nozzle 16 in the tundish, be provided with in the bottom of tundish 24 and solidify cavity 15, in solidifying cavity, add solidification liquid 36 is arranged, this top of solidifying cavity 15 is the opening shape, between upper end of solidifying cavity 15 and tundish 24 bottoms, be provided with and spray closed cavity 20, be connected with ball valve 10 in the bottom of solidifying cavity 15, the bottom of this ball valve 10 is connected with gatherer 9.Be connected with ball valve 39 in this gatherer lower end, close ball valve 10, open ball valve 39, the solder globules in the gatherer 9 can be exported; Close ball valve 39, open ball valve 10, can in solidifying cavity 15, carry solidification liquid 36 by carrier pipe 38; Solder globules can enter in the gatherer 9 by the ball valve of opening 10.
It also includes pressure difference transmitter 12 preparation facilities of this precise welded ball, adopt TY-1151DP/GP series transmitter, two sensors 8 of control pressure difference transmitter work, 19, one is arranged in the melting kettle 3 by line, another is arranged on by line and sprays in the closed cavity 20, pressure in the melting kettle 3 is 200KPa, spraying in the closed cavity 20 is 101KPa (1 atmospheric pressure), the loam cake 4 of melting kettle 3 is provided with and enters in the melting kettle 7 and be connected with pressure difference transmitter 12, be connected with flow pump 18 on carrier pipe 13, this flow pump 18 is connected with pressure difference transmitter 12 by control line 17.
The lateral wall of melting kettle 3 is provided with heater 2, lateral wall at tundish 24 is provided with heating sheath 21, thermocouple 11 is installed in solidifying cavity 15, be used to detect, control the thermograde of solidification liquid 36, be provided with the heating sheath 14 of formation temperature gradient distribution from top to bottom at the lateral wall that solidifies cavity 15.
Be connected with tracheae 26 on the sidewall of tundish 24, this tracheae 26 is connected with vacuum valve 28 respectively with protection gas appendix 27 and is connected; Be connected with another tracheae 26 on the sidewall that sprays closed cavity 20, this tracheae 26 is connected with another vacuum valve 29 respectively with another protection gas appendix 32 and is connected; Two vacuum valves 28,29 connect 31 by tracheae and vavuum pump and connect.
Upper side wall at gatherer 9 is connected with solidification liquid carrier pipe 38, and the other end hydraulic motor 40 of this carrier pipe 38 connects, and this hydraulic motor 40 is connected with solidification liquid storage tank 37; Penetrated an overflow pipe 33 at the downside wall that solidifies cavity 15, this overflow pipe 33 is along the madial wall setting of solidifying cavity, and the top of this overflow pipe 33 is a little less than the top of solidifying cavity 15; Be connected with another overflow pipe 30 at the diapire that sprays closed cavity 20, the lower end of these two overflow pipes is communicated with the back and is connected with the liquid back pipe 34 of condenser 35, and this condenser 35 is connected to form the circulatory system with solidification liquid storage tank 37.
Described ultra micro nozzle is single hole 41 or porous, and the diameter range of its ultra micro nozzle is between 0.050~5.000mm, and draw ratio is 1: 2~6; The vibration frequency range of piezoelectric vibration exciter is between 1~20kHz.