A kind of production method of ultra-thin graphite slice
Technical field
The present invention relates to a kind of production methods of ultra-thin graphite slice.
Background technique
As consumer constantly pursues electronic products such as mobile phone, tablet computers ultra-thin requirement, the design of electronic product
Space is challenged constantly, and the volume of various components is all past to become small, and function becomes strong direction and develops, because
This in a limited space in how to solve heat dissipation also at one challenge.
Artificial synthesized graphite flake is most common heat sink material.Classify by thickness, have in industry at present 25U, 40U,
Tri- kinds of thickness of 17U.This thickness is decided by PI film (Kapton, by pyromellitic acid anhydride (PMDA) and two amido hexichol
Ether (DDE) in intensive polar solvent through polycondensation and casting film-forming is formed through imidization again) thickness and sintering process and calendering
Technique.The PI film thickness of corresponding tri- kinds of graphite thickness of 25U, 40U, 17U is respectively 50U, 75U, 38U, the thickness of graphite and PI film
Than close to 1:2 ratio.Theoretically graphite thickness can accomplish 5U, but in fact, be limited by sintering process and calendering technology, mesh
Most thin 17U under the premise of retention property can only be accomplished in the industry by moving ahead.
The space of electronic product limits, and the graphite thickness of 17U may exceed design space in next application,
Ask accomplish it is thinner.
Moreover, being divided according to thermal coefficient: the corresponding thermal coefficient of 25U, 40U, 17U graphite be 1500W/m.K,
1300W/m.K,1700W/m.K.Graphite is thinner as can be seen from the above data, and thermal coefficient is higher, and heating conduction is better.Reason
It is that the more thin degree of graphitization during the sintering process of PI film is higher.
Graphite flake generally includes two processes when production, is respectively carbonized and is graphitized.PI film is placed on carbonization
Heat temperature raising in furnace makes the other compositions inside PI membrane material other than carbon atom with gas by the control of different temperatures
Mode excludes.PI film can be shunk during temperature rises, and contraction while can cause surface folding, temperature control
It is bad, it will cause product surface buckling problems are very serious, cause to produce defective products.It is graphitized, is put again after carbonization
Enter and be heated at high temperature in graphitizing furnace body, recombinate high purity carbon material internal atomic structure after being carbonized, is formed
The atomic structure of carbon of regulation arrangement, i.e., artificial synthesized graphite.During heat temperature raising, temperature control is improper, can make PI
Membrane area increases, so that thinner product can not be produced.
Summary of the invention
The technical problem to be solved in the present invention is to provide a kind of production method of ultra-thin graphite slice, obtained graphite flake is thermally conductive
Performance is good.
In order to solve the above-mentioned technical problem, the present invention takes following scheme:
A kind of production method of ultra-thin graphite slice, comprising the following steps:
Carbonization, the PI film of 19U is placed in carbide furnace and carries out heat temperature raising, the temperature in carbide furnace is made to be raised to 1300
DEG C, during heating, maintained 40-50 minutes in 300 DEG C of temperature range sections below, 300-650 DEG C of temperature range section
It maintains 230-250 minutes, 650-850 DEG C of temperature range section maintains 65-75 minutes, and 850-1300 DEG C of temperature range section maintains
165-175 minutes, then obtain semi-finished product;
It is cooling, the semi-finished product for completing carbonization are cooled down;
Graphitization, semi-finished product after cooling are put into graphitizing furnace body and carry out heat temperature raising, make the temperature of graphitizing furnace
2930 DEG C are raised to, in the process of heating, is maintained 25-35 minutes in 1000 DEG C of temperature range sections below, 1000-1700 DEG C
Temperature range section maintains 85-95 minutes, and 1700-2200 DEG C of temperature range section maintains 145-155 minutes, 2200-2600 DEG C
Temperature range section maintains 105-115 minutes, and 2600-2930 DEG C of temperature range section maintains 255-265 minutes, and then cooling obtains
The graphite flake finished product of 10U.
In the carbonisation, the heating process of each temperature range section is respectively with the rising of stationary temperature value, wherein 300 DEG C
Temperature range section below is heated up with 6.6-6.7 DEG C/min of speed, 300-650 DEG C of temperature range section with 1.4-1.53 DEG C/
The speed heating of minute, 650-850 DEG C of temperature range section are heated up with 2.7-3.1 DEG C/min of speed, 850-1300 DEG C of temperature
Segment is spent to heat up with 2.6-2.8 DEG C/min of speed.
In the carbonisation, maintain 45 minutes and in 300 DEG C of temperature range sections below with 6.67 DEG C/min of speed
Heating, 300-650 DEG C of temperature range section maintain 240 minutes and with the heating of 1.49 DEG C/min of speed, 650-850 DEG C of temperature
Segment is spent to maintain 70 minutes and with the heating of 2.86 DEG C/min of speed, 850-1300 DEG C of temperature range section maintenance 170 minutes
And with the heating of 2.65 DEG C/min of speed.
In the graphitizing process, the heating process of each temperature range section is respectively with the rising of stationary temperature value, 1000
DEG C temperature range section below is heated up with 31-34 DEG C/min of speed, and 1000-1700 DEG C of temperature range section is with 7.4-8.3
DEG C/min speed heating, 1700-2200 DEG C of temperature range section heats up with 3.3-3.5 DEG C/min of speed, 2200-2600
DEG C temperature range section heated up with 3.5-3.81 DEG C/min of speed, 2600-2930 DEG C of temperature range section is with 1.25-1.3
DEG C/min speed heating.
In the graphitizing process, maintain 30 minutes and in 1000 DEG C of temperature range sections below with 33.33 DEG C/min
Speed heating, 1000-1700 DEG C of temperature range section maintain 90 minutes and with the heating of 7.78 DEG C/min of speed, 1700-2200
DEG C temperature range section maintain 150 minutes and with 3.33 DEG C/min of speed heating, 2200-2600 DEG C of temperature range Duan Wei
It holds 110 minutes and is heated up with 3.64 DEG C/min of speed, 2600-2930 DEG C of temperature range section maintains 260 minutes and with 1.27
DEG C/min speed heating.
The present invention by carbonisation and graphitizing process different temperatures segment hold time and heating rate
Control guarantees to also ensure that good heating conduction while graphite flake thinness.
Detailed description of the invention
Attached drawing 1 is the curve synoptic diagram of carbonisation of the present invention;
Attached drawing 2 is the curve synoptic diagram of graphitizing process of the present invention.
Specific embodiment
For the ease of the understanding of those skilled in the art, a pair of of present invention makees further to retouch combined with specific embodiments below
It states.
Embodiment one
A kind of production method of ultra-thin graphite slice, comprising the following steps:
S1, carbonization, as shown in Fig. 1, the PI film of 19U is placed in carbide furnace and carries out heat temperature raising, is made in carbide furnace
Temperature be raised to 1300 DEG C, during heating, maintained 40 minutes in 300 DEG C of temperature range sections below and with 6.7 DEG C/minute
The speed of clock at the uniform velocity rises, and 300-650 DEG C of temperature range section is maintained 230 minutes and at the uniform velocity risen with 1.53 DEG C/min of speed
Temperature, 650-850 DEG C of temperature range section are maintained 65 minutes and are at the uniform velocity heated up with 3.1 DEG C/min of speed, 850-1300 DEG C of temperature
Degree segment is maintained 165 minutes and is at the uniform velocity heated up with 2.8 DEG C/min of speed, and semi-finished product are then obtained.In each temperature range
Duan Zhong keeps current time until Current Temperatures area if not reaching when temperature is raised to high critical value but also and holding time
Between the corresponding end of holding time of section.By the carbonization, so that the other compositions inside PI membrane material other than carbon atom are with gas
The mode of body excludes.By the way that carbonisation is divided into above four temperature range sections, and control each temperature range section
Temperature hold-time and heating rate, different temperature range sections using different heatings continue or the retention time, guarantee
The phenomenon that PI film can slowly be shunk in different temperatures segment, reduce fold, avoids fold.
S2, it is cooling, the semi-finished product for completing carbonization are cooled down.It is usually cooled to room temperature, convenient for taking.
S3, graphitization, as shown in Fig. 2, semi-finished product after cooling is put into graphitizing furnace body and carry out heat temperature raising, are made
The temperature of graphitizing furnace is raised to 2930 DEG C, during heating, maintain 25 minutes in 1000 DEG C of temperature range sections below and
It is heated up with 34 DEG C/min of speed, 1000-1700 DEG C of temperature range section maintains 85 minutes and with 8.3 DEG C/min of speed liter
Temperature, 1700-2200 DEG C of temperature range section maintain 145 minutes and with the heating of 3.5 DEG C/min of speed, 2200-2600 DEG C of temperature
Segment is spent to maintain 105 minutes and with the heating of 3.81 DEG C/min of speed, 2600-2930 DEG C of 255 points of temperature range section maintenance
Clock and with 1.3 DEG C/min of speed heating, then cooling obtain the graphite flake finished product of 10U, the thermal coefficient of the graphite flake finished product
It can reach 1900W/m.K.By the way that the temperature range of graphitizing process is divided into above-described five temperature range sections, and
Different temperature range sections is continued using different heatings or the retention time.By it is experimentally confirmed that passing through control 2200-2600
DEG C temperature range section the heating duration so that the strong sufficiently fracture of the original atom of PI film, then control 2600-2930 DEG C
The heating duration of temperature range section, combine the carbon atom for being broken atom key adequately, to guarantee to fill
The graphitization divided, improves the thermal coefficient of graphite flake, thermal coefficient can reach 1900W/m.K.
Embodiment two
A kind of production method of ultra-thin graphite slice, comprising the following steps:
S1, carbonization, the PI film of 19U is placed in carbide furnace and carries out heat temperature raising, is raised to the temperature in carbide furnace
It 1300 DEG C, during heating, maintains 45 minutes and in 300 DEG C of temperature range sections below with 6.67 DEG C/min of speed
It at the uniform velocity heats up, 300-650 DEG C of temperature range section is maintained 240 minutes and at the uniform velocity heated up with 1.49 DEG C/min of speed, 650-
850 DEG C of temperature range section is maintained 70 minutes and is at the uniform velocity heated up with 2.86 DEG C/min of speed, 850-1300 DEG C of temperature range
Section maintains 170 minutes and with the heating of 2.65 DEG C/min of speed, then obtains semi-finished product.In each temperature range section, if
It does not reach when temperature is raised to high critical value but also and holds time, then keep current time until Current Temperatures segment is corresponding
It holds time end.By the carbonization, so that the other compositions inside PI membrane material other than carbon atom are arranged in a manner of gas
It removes.By the way that carbonisation is divided into above four temperature range sections, and the temperature for controlling each temperature range section is kept
Time and heating rate, different temperature range sections is continued using different heatings or the retention time, guarantee PI film in difference
The phenomenon that can slowly shrinking in temperature range section, reducing fold, avoid fold.
S2, it is cooling, the semi-finished product for completing carbonization are cooled down.It is usually cooled to room temperature, convenient for taking.
S3, graphitization, semi-finished product after cooling are put into graphitizing furnace body and carry out heat temperature raising, make the temperature of graphitizing furnace
Degree is raised to 2930 DEG C, during heating, maintains 30 minutes and in 1000 DEG C of temperature range sections below with 33.33 DEG C/minute
The speed of clock heats up, and 1000-1700 DEG C of temperature range section maintains 90 minutes and with the heating of 7.78 DEG C/min of speed, 1700-
2200 DEG C of temperature range section maintains 150 minutes and with the heating of 3.33 DEG C/min of speed, 2200-2600 DEG C of temperature range
Section maintains 110 minutes and with the heating of 3.64 DEG C/min of speed, 2600-2930 DEG C of temperature range section maintain 260 minutes and with
1.27 DEG C/min of speed heating, then cooling obtains the graphite flake finished product of 10U, and the thermal coefficient of the graphite flake finished product is reachable
To 1900W/m.K.By the way that the temperature range of graphitizing process is divided into above-described five temperature range sections, and it is different
Temperature range section continued or the retention time using different heatings.By it is experimentally confirmed that passing through 2200-2600 DEG C of control
The heating duration of temperature range section is sufficiently broken so that the original atom of PI film is strong, then controls 2600-2930 DEG C of temperature
The heating duration of segment, combine the carbon atom for being broken atom key adequately, to guarantee sufficient
Graphitization, improves the thermal coefficient of graphite flake, thermal coefficient can reach 1900W/m.K.
Embodiment three
A kind of production method of ultra-thin graphite slice, comprising the following steps:
S1, carbonization, the PI film of 19U is placed in carbide furnace and carries out heat temperature raising, is raised to the temperature in carbide furnace
It 1300 DEG C, during heating, is maintained 50 minutes in 300 DEG C of temperature range sections below and even with 6.6 DEG C/min of speed
Speed heating, 300-650 DEG C of temperature range section are maintained 245 minutes and are at the uniform velocity heated up with 1.4 DEG C/min of speed, and 650-850 DEG C
Temperature range section maintain 75 minutes and at the uniform velocity to heat up with 2.7 DEG C/min of speed, 850-1300 DEG C of temperature range section maintains
175 minutes and with 2.6 DEG C/min of speed heating, then obtain semi-finished product.In each temperature range section, if temperature liter
It does not reach when to high critical value but also and holds time, then keep current time until when the corresponding maintenance of Current Temperatures segment
Between terminate.By the carbonization, so that the other compositions inside PI membrane material other than carbon atom are excluded in a manner of gas.It is logical
Cross and carbonisation be divided into above four temperature range sections, and control each temperature range section temperature hold-time and
Heating rate, different temperature range sections is continued using different heatings or the retention time, guarantee PI film in different temperatures section
The phenomenon that can slowly shrinking in section, reducing fold, avoid fold.
S2, it is cooling, the semi-finished product for completing carbonization are cooled down.It is usually cooled to room temperature, convenient for taking.
S3, graphitization, semi-finished product after cooling are put into graphitizing furnace body and carry out heat temperature raising, make the temperature of graphitizing furnace
Degree is raised to 2930 DEG C, during heating, maintains 35 minutes and in 1000 DEG C of temperature range sections below with 31 DEG C/min
Speed heating, 1000-1700 DEG C of temperature range section maintain 95 minutes and with the heating of 7.4 DEG C/min of speed, 1700-2200
DEG C temperature range section maintain 155 minutes and with the heating of 3.3 DEG C/min of speed, 2200-2600 DEG C of temperature range section maintains
115 minutes and with the heating of 3.5 DEG C/min of speed, 2600-2930 DEG C of temperature range section maintain 265 minutes and with 1.25 DEG C/
The speed heating of minute, then cooling obtains the graphite flake finished product of 10U, and the thermal coefficient of the graphite flake finished product can reach 1900W/
m.K.By the way that the temperature range of graphitizing process is divided into above-described five temperature range sections, and different humidity provinces
Between section continued or the retention time using different heatings.By it is experimentally confirmed that passing through the temperature range of 2200-2600 DEG C of control
The heating duration of section, so that the strong sufficiently fracture of the original atom of PI film, then control 2600-2930 DEG C of temperature range section
It heats up the duration, combines the carbon atom for being broken atom key adequately, to guarantee adequately graphitization, mention
The thermal coefficient of high graphite flake, thermal coefficient can reach 1900W/m.K.
It should be noted that the above is not limited to the present invention, concept of the invention is not being departed from
Under the premise of, it is any obviously replace it is within the scope of the present invention.