CN105175993A - Preparation method for hybrid filling composite castable with high thermal conductivity - Google Patents

Abstract

The present invention discloses a preparation method for hybrid filling composite castable with high thermal conductivity. The preparation method comprises: adding liquid epoxy resin into a thin-layer defoaming kettle while stirring, adding hybrid filler when the temperature is raised to 85-95 DEG C, uniformly stirring and then carrying out decompression defoaming until no bubble releases, thereby obtaining a component A; adding a toughening agent and a curing agent into a second thin-layer defoaming kettle, adding an accelerator after stirring, adding the remaining hybrid filler when the temperature is raised to 80-90 DEG C, uniformly stirring, and carrying out vacuum degassing until no bubble releases, thereby obtaining a component C; and transferring the component A into a third thin-layer defoaming kettle while stirring, controlling the temperature of the material to be stable at 80-90 DEG C, adding the component B, stirring and defoaming for 0.5 hour at the temperature of 80-90 DEG C and under the pressure of 100-200 Pa, thereby obtaining the hybrid filled composite castable with high thermal conductivity. According to the method disclosed by the invention, the operation is simple, the manufacturing cost is low, and a composite material after carrying out casting molding on the obtained hybrid filled composite castable with high thermal conductivity has excellent properties.

Description

One specific admixture fills the preparation method of high heat conduction composite casting material

Technical field

The invention belongs to technical field of composite preparation, particularly a specific admixture fills the preparation method of high heat conduction composite casting material.

Background technology

Epoxy resin encapsulated material is widely used in Electronic Packaging field, for with the encapsulation of epoxy resin encapsulated material to electronics, in order to reduce electronic package material linear expansivity, improve electronic package material heat-conductive characteristic, improve the heat radiation of electronic devices and components, usually need in Embedding Material, add a certain amount of inorganic powder.

The inorganic powder added in existing epoxy electronic package material is more single, mainly silicon powder or title silica powder.One of advantage of silicon powder is cheap, and another advantage is that density is smaller, only has 2.2 ~ 2.65g/cm ³, in epoxy electronic package material solidification process, powder is not easy to precipitate because of action of gravity; Shortcoming is that thermal conductivity is lower, only has 5 ~ 9W/ (mk) left and right, therefore the thermal conductivity of the mould material of existing employing silicon powder filling is lower, only has 0.5 ~ 0.6W/ (mk) left and right, is unfavorable for the heat radiation of pot electronics components and parts and reduces operating temperature.

Along with the development of Powder Processing Technology in China, a batch of manufacturing cost with the inorganic powder of more high thermal conductivity coefficient has had and has significantly reduced, such as the sale of aluminum oxide powder is at present just close to silicon powder, and the thermal conductivity of aluminum oxide powder is up to 28 ~ 30W/ (mk).Only from the angle of cost of manufacture, the inorganic powder these with more high thermal conductivity coefficient is applied to the manufacture of epoxy electronic encapsulation material, and by the heat conductive filler modification of different size and kind and optimizing matching, significantly can improve the heat-conductive characteristic of Embedding Material, improve the heat radiation of pot electronics components and parts, reduce the temperature rise of pot electronics components and parts.

The difficulty that inorganic powder higher for thermal conductivity is applied to epoxy fill-sealing materials be mainly: the powder that these thermal conductivitys are higher, general density is all larger, and mould material than being easier to, sedimentation occurs in the curing process; Moreover be exactly that heat conductive filler needs certain process modification and size combinations optimization, make combination better, this is the technical barrier that high heat conduction inorganic powder is applied to the solution of epoxy electronic encapsulation material needs.

Summary of the invention

The object of the invention is for the deficiencies in the prior art, provide a specific admixture to fill the preparation method of high heat conduction composite casting material.

For solving the problems of the technologies described above, the present invention by adopt high heat conduction inorganic powder to substitute silicon powder that prior art uses as the method for filler and mix filling by the heat conductive filler combination that large small particle size is different and modified optimization improves the thermal conductivity of mould material.In order to eliminate the phenomenon that high heat conduction inorganic powder, because density ratio is comparatively large, sedimentation easily occurs, this invention takes three technical measures: one is adopt the CNT (carbon nano-tube) Combinatorial Optimization of density is little, thermal conductivity is high, price is low nanometer aluminium powder and excellent heat conductivity performance significantly to improve thermal conductivity; Two is the toughner selecting hydroxy radical content higher, while improving cured article tough, strengthens the reactive force between inorganic powder and matrix resin molecule; Three be optimize the formula of mould material and mixed glue deaeration technique, controls material viscosity larger as far as possible in exercisable scope, slow down the sedimentation of high heat conduction inorganic powder further.

Concrete steps are:

(1) raw material is taken according to following mass ratio, liquid epoxies: toughner: solidifying agent: promotor: mix filler=110:8 ~ 16:80 ~ 110:0.4 ~ 0.6:30 ~ 50.

(2) liquid epoxies that step (1) takes is dropped in first thin layer deaeration still, start stirring, that drops into when being warming up to 85 ~ 95 DEG C that 1/2nd amount steps (1) take mixes filler, vacuum deaerator after stirring, deaeration is to bubble-free is released in 100 ~ 105 DEG C and under 100 ~ 200Pa condition, obtains component A.

(3) toughner step (1) taken and solidifying agent drop in second thin layer deaeration still, the promotor that step (1) takes is dropped into after starting stirring, that drops into when being warming up to 80 ~ 90 DEG C that remaining step (1) takes mixes filler, vacuum deaerator after stirring, deaeration is to bubble-free is released in 90 ~ 100 DEG C and under 100 ~ 200Pa condition, obtains B component.

(4) component A that step (2) is obtained is transferred in the 3rd thin layer deaeration still, start stirring, after control temperature of charge is stabilized in 80 ~ 90 DEG C, drop into the B component that step (3) is obtained again, stir deaeration 0.5 hour under 100 ~ 200Pa condition at 80 ~ 90 DEG C, namely obtained mixing fills high heat conduction composite casting material.It is shaping that this mould material can be used in Electronic Packaging vacuum pouring.

Described liquid epoxies is bisphenol f type epoxy resin, aliphatic epoxy resin or cycloaliphatic epoxy resin.

Described toughner is aliphatic poly ethoxylated polyhydric alcohol or aromatic polyether polyvalent alcohol.

Described solidifying agent is methyl hexahydro phthalic anhydride or methyl Nai Dike acid anhydrides.

Described promotor is N, N ,-dimethyl benzylamine or liquid imidazole.

The described filler that mixes is prepared as follows: the carbon nanotube and the nm-class boron nitride powder that the quality such as to take are uniformly mixed, adding the coupling agent accounting for mixture quality 0.5 ~ 3% wherein carries out surface treatment simultaneously, treatment temp is set to 60 ~ 80 DEG C, treatment time is 90 minutes, then at 120 DEG C dry 4 hours, namely obtainedly filler is mixed; Described carbon nanotube particle diameter is 100 ~ 1000 nanometers, and Nano powder of silicon nitride particle diameter is 1 ~ 100 nanometer, and described coupling agent is one or more in silane coupling agent, titanate coupling agent or titanium aluminate coupling agent.

The inventive method is simple to operate, low cost of manufacture, and equipment is simple, and obtained mix the matrix material after filling high heat conduction composite casting material casting and have that thermal conductivity is high, good heat dissipation effect and the light advantage of quality.

Embodiment

embodiment:

(1) take raw material according to following quality, CYD128 epoxy resin 110kg, polytetrahydrofuran diol 12kg, methyl hexahydro phthalic anhydride 95kg, N, N ,-dimethyl benzylamine 0.5kg, mixes filler 40kg.

(2) the CYD128 epoxy resin that step (1) takes is dropped in first thin layer deaeration still, start stirring, that drops into when being warming up to 90 DEG C that 20kg step (1) takes mixes filler, vacuum deaerator after stirring, deaeration is to bubble-free is released in 100 DEG C and under 150Pa condition, obtains component A.

(3) polytetrahydrofuran diol step (1) taken and methyl hexahydro phthalic anhydride drop in second thin layer deaeration still, the N that step (1) takes is dropped into after starting stirring, N,-dimethyl benzylamine, that drops into when being warming up to 85 DEG C that remaining 20kg step (1) takes mixes filler, vacuum deaerator after stirring, deaeration is to bubble-free is released in 95 DEG C and under 150Pa condition, obtains B component.

(4) component A that step (2) is obtained is transferred in the 3rd thin layer deaeration still, start stirring, after control temperature of charge is stabilized in 85 DEG C, drop into the B component that step (3) is obtained again, stir deaeration 0.5 hour under 150Pa condition at 85 DEG C, namely obtained mixing fills high heat conduction composite casting material.

The described filler that mixes is prepared as follows: the carbon nanotube and the nm-class boron nitride powder that the quality such as to take are uniformly mixed, adding the KH560 accounting for mixture quality 2% wherein carries out surface treatment simultaneously, treatment temp is set to 70 DEG C, treatment time is 90 minutes, then at 120 DEG C dry 4 hours, namely obtainedly filler is mixed; Described carbon nanotube particle diameter is 700 nanometers, and Nano powder of silicon nitride particle diameter is 80 nanometers.

What the present embodiment was obtained mix fills high heat conduction composite casting material and solidifies at 150 DEG C after 5 hours, and the thermal conductivity of gained cured article is 2.75w/(mk); Workpiece top density 2.455g/cm ³, workpiece bottom density is 2.464g/cm ³; Shock strength is 17kJ/m ²; Flexural strength 140MPa; Heat-drawn wire is 115 DEG C; Breaking down field strength is 29kv/cm ³; Linear expansivity is 43x10 ^-6k ^-1, all comparatively excellent.

Claims (1)

1. a specific admixture fills the preparation method of high heat conduction composite casting material, it is characterized in that concrete steps are:

(1) raw material is taken according to following mass ratio, liquid epoxies: toughner: solidifying agent: promotor: mix filler=110:8 ~ 16:80 ~ 110:0.4 ~ 0.6:30 ~ 50;

(2) liquid epoxies that step (1) takes is dropped in first thin layer deaeration still, start stirring, that drops into when being warming up to 85 ~ 95 DEG C that 1/2nd amount steps (1) take mixes filler, vacuum deaerator after stirring, deaeration is to bubble-free is released in 100 ~ 105 DEG C and under 100 ~ 200Pa condition, obtains component A;

(3) toughner step (1) taken and solidifying agent drop in second thin layer deaeration still, the promotor that step (1) takes is dropped into after starting stirring, that drops into when being warming up to 80 ~ 90 DEG C that remaining step (1) takes mixes filler, vacuum deaerator after stirring, deaeration is to bubble-free is released in 90 ~ 100 DEG C and under 100 ~ 200Pa condition, obtains B component;

(4) component A that step (2) is obtained is transferred in the 3rd thin layer deaeration still, start stirring, after control temperature of charge is stabilized in 80 ~ 90 DEG C, drop into the B component that step (3) is obtained again, stir deaeration 0.5 hour under 100 ~ 200Pa condition at 80 ~ 90 DEG C, namely obtained mixing fills high heat conduction composite casting material;

Described liquid epoxies is bisphenol f type epoxy resin, aliphatic epoxy resin or cycloaliphatic epoxy resin;

Described toughner is aliphatic poly ethoxylated polyhydric alcohol or aromatic polyether polyvalent alcohol;

Described solidifying agent is methyl hexahydro phthalic anhydride or methyl Nai Dike acid anhydrides;

Described promotor is N, N ,-dimethyl benzylamine or liquid imidazole;

The described filler that mixes is prepared as follows: the carbon nanotube and the nm-class boron nitride powder that the quality such as to take are uniformly mixed, adding the coupling agent accounting for mixture quality 0.5 ~ 3% wherein carries out surface treatment simultaneously, treatment temp is set to 60 ~ 80 DEG C, treatment time is 90 minutes, then at 120 DEG C dry 4 hours, namely obtainedly filler is mixed; Described carbon nanotube particle diameter is 100 ~ 1000 nanometers, and Nano powder of silicon nitride particle diameter is 1 ~ 100 nanometer, and described coupling agent is one or more in silane coupling agent, titanate coupling agent or titanium aluminate coupling agent.