CN1552941A - Abrasion resistant coated process of miniature cutter - Google Patents

Abstract

This invention relates to a process to coat a wear resistance film with thickness of 0.5 - 3um onto miniature machining tools, which can be sintered tungsten carbide or tungsten carbide cermet milling cutters or drill bits with shank diameters <4mm. Its constituent is ZrHfCN with Hf content of 0 - 10 wt%. It has good adhesion strength and can works at higher speed and with longer service life. Actually, it can make service life of tools 1.5 - 3 times long in machining printed circuit boards.

Description

The wear-resistant coating process method of miniature cutting tool

Technical field

The present invention relates to utilize physical vapor deposition (Physical Vapor Deposition, PVD), the principle of icon bombardment cleaning and Ion Aided Film Coating (ion-assistant coating), the ultra tiny ion particles of multielement is coated on the mini milling cutter surface forms film, especially a kind of zirconium (Zr), hafnium (Hf), carbon (C), nitrogen (N) multielement rete are coated in wolfram varbide sintering superhard alloy (SinteredTungsten Carbide) or the microbit of wolfram varbide porcelain gold (Tungsten Carbide Cermet) and the processing method on the milling cutter.

Background technology

Shank diameter (Shank Diameter) is that 3.175 millimeters miniature sizes drill bit (Drill) often is installed on drilling machine and the milling machine with milling cutter (Router), in order at printed circuit board (PCB) (PrintingCircuit Board, PCB) hole on the baseplate material and cut, these substrates are formed by glass fibre (Glass Fiber) compacting basically, some in addition add multilayer copper foil or tetrafluoroethylene (PTEF), therefore very diversified, thus the degree of difficulty of processing increased; In addition along with the dwindling of circuit card size, so circuit line width and line-spacing contract suddenly, make on the size accuracy of processing, require harsh day by day.In modernization and the milling machine of automated operation operation factory, increasing production capacity be that dealer institute profoundly hopes for, and the dealer more wishes under the condition that does not increase machine and increase overall production capacity, because the expense of the purchasing board the highest ring of finished product manufacturing cost proportion normally.Therefore have higher cutting ability, hardness is better, wear resistance is better, microbit that life-span is longer and milling cutter, be the active demand of circuit card industry institute, so industry wishes to plate the better film of sticking power on min-cutter, so that the better plated film min-cutter of quality has high rigidity, and can bear high rotational speed, and then can increase feeding speed and increase the production capacity of cutting.The present invention promptly makes great efforts to develop the batch production technique method of the ultra tiny ion particles multielement of a coating one deck film on min-cutter at this problem and demand.

The wear-resistant coating technique of existing cutting tool is divided into chemical vapour deposition (Chemical VaporDeposition, CVD) method and physical vaporous deposition two big classes, how the former at high temperature carries out vacuum plating, its processing method temperature is generally about 400 ℃ to 1200 ℃, so that carry out transition metal nitride (Nitride), the film deposition reaction of carbide (Carbide) or carbonitride (Carbon-nitride), for example disclosedly in U.S. Pat 5693408 carry out the lower temperature processing method with PCVD (Glow-discharge Activated CVD) method, its temperature range is also up to 400-900 ℃, though can deposit the ZrCN wearing layer, but will cause damage on the min-cutter blade tip with softening because its processing method temperature is too high, employed in addition reactant contains metal halide gas and belongs to hypertoxicity, so the doubt of public safety and environmental protection control is arranged.

And in using physical vaporous deposition, primary is sputter or sputter (Sputtering) method, its Controllable Temperature is built in below 400 ℃, the sputtering process method of carbide, nitride or the oxide compound of more disclosed transitional metals among the English Patent GB2226334 for example, these coating are only for being applied in dimension Ke Shi hardness (Vickers ' Hardness) less than on 300 the metal base, if the dimension Ke Shi hardness of base material is greater than 300 when above, will cause and adhere to badly between coating and the base material, and cause bad wear-resistant and corrosion-resistance properties.Therefore, the less still difficult wear-resistant plated film that is applied to min-cutter of sputtering technology of ion energy.

Summary of the invention

The invention discloses and utilize the principle of low-temperature physics vapour deposition, ion cleaning, Ion Aided Film Coating to plate ZrCN or ZrHfCN multielement superhard thin film at microbit and milling cutter, the shank diameter of microbit that printed circuit board industry is used and milling cutter (Shank Diameter) is below 4mm, and its mother metal is wolfram varbide superhard alloy or porcelain gold.According to the present invention, the thickness of this ZrCN or ZrHfCN multielement superhard thin film is 0.5-3 micron (μ m), does not therefore influence the blade tip size of cutter own.

Purpose of the present invention, provide a kind of processing method that plates ZrCN or ZrHfCN multielement film on microbit and milling cutter surface, the particle that is plating material simultaneously is little, sticking power is good, this plated film can be with finishing not come off yet to cutter life, and the technology weak point that expends time in, the surface of cutter is hard, inner tough behind the plated film, wear resistance increases, heat radiation is good, apparent size is constant, and and then promote its cutting speed in printed circuit board base board processing, can not only prolong cutter life and promote the size precision of machining.

Therefore the invention provides a kind of program of low-temperature physics vapour deposition, plated body cleans the plated body surface with ionic fluid in a vacuum, carries out overlay film at low temperature then.Utilize arc ions evaporation (Arc Ion Evaporation) device that evaporation of metal is pounded and ionization in the process, and utilize filtering net to filter out the little ion of particle, use the ion supplementary unit (Ion Assistant Device) further will be simultaneously by the further refinement of the ion of filter screen, the particle of the material of the plated body that is coated in is little, sticking power is big, therefore had the surface firmly by the cutter behind the plated film, inner tough advantage, therefore cutting speed improves, wear resistance improves, the cutting size is accurate, cutting anti-folding rate improves, and increase work-ing life, simultaneously the processing method time shortens, overcome existing PVD can't be on microbit and milling cutter coating obtain the problem of good adhesion.

The present invention's other purpose and function are described further by cooperating following accompanying drawing.

It is as follows that the present invention carries out coating process method (as Fig. 1):

A. load plated body in anchor clamps, under normality, clean and dry;

B. load these anchor clamps in vacuum oven, vacuumize, heat to 120 ℃-400 ℃;

C. utilize ion unit (ion device) to get ion to clean this plated body surface; This ion unit can be ion gun;

D. carry out plated film:

(i) utilize arc gum (ARC source) to get minitype ion, assisted with ion gun again, the ion of ARC running back is done once littler refinement with ion gun (Ion Source) with it again from target (target);

(ii) between target and plated body, add last layer and filter, small ion is passed through, and macrobead by the net filter down with metal screen.This filter screen, is beneficial to tiny ion and passes through in order to avoid form electrode with the isolated conduction of insulating ceramic.Above-mentioned small ion is done once littler refinement through ion gun again and just is coated in plated body;

E. feed the mixed gas of methane (CH4) or acetylene (C2H2) or propane (C3H8) and nitrogen;

F. use nitrogen cooling plated body.

Earlier plated body (microbit or milling cutter) is loaded anchor clamps 7 (ginseng Fig. 1) before the plated film, before plated film, clean the surface blot of all blades earlier, oven dry places vacuum oven with min-cutter together with anchor clamps more then.After the vacuum that is evacuated in the vacuum oven below the 10-5torr, begin to heat.Heat to the temperature of setting (120-400 ℃), (Ion cleaning device) gets ion bombardment plated body surface with the ion washing unit, removes the dirty and oxide compound on plated body surface, this oxide compound afterwards contact because of plated body cleans with air produce.This process can be determined the absolute cleaning in the surface of plated body, pollution-free material, and the good condition of adhering to can be provided, and increase coating adhesion.

After utilizing ion to clean, begin to carry out film coating operation, this operation is carried out under vacuum, low-temperature condition.With arc ions equipment (as Fig. 1), metal ion is got from target, because may there be bigger molecule particle in the ion that arc gum is got, so the present invention utilizes ion supplementary unit (Ionassistant device) fining metal ion, makes its particle littler.The micro metal ion that arc gum is up to is assisted with ion gun ion supplementary unit again, with the metal ion of its arc gum running back with ion gun with its littler ionization that tries again.Because ion is littler, and is endowed bigger kinetic energy during the course, therefore easier adhering to, simultaneously easilier form unbreakable multielement metal compound film with the element ions compatibility of other needs, impel the film hardness height, good attachment, density are also high.Be very important so ion is auxiliary.

In addition, between target and plated body (as Fig. 2), add last layer and come filter ions according to different size plated body filtering net 13 designed, that be used for different void size, reduce the speed of metal ion 11, so that the ion supplementary unit has than plenty of time separating metal ion 11, and small ion is passed through, and macrobead is filtered net 13 filters down, what microbit or milling cutter were accompanying is identical extra small ion particles entirely, so can closely be attached on the plated body.Thus, can guarantee the plated body surface smoothness, more can guarantee the cutting quality that it is good.Filtering net 13 is generally metallic substance, and what use around the filtering net of metal is insulating material insulation such as pottery, and filter screen does not form electrode, makes tiny ion be easy to be coated on the plated body by filter screen.Operational temperature is 120 ℃-400 ℃ during plated film, and symbolic animal of the birth year is to subzero treatment, because the present invention has the handling procedure of ion cleaning (Ion cleaning) and ion auxiliary (Ion assistant), so can operate at low temperature.So quilt plating cutter toughness can not reduce, and the hardness more than two times is arranged behind the overlay film, the tack of coating film (adhesion) is good, and is wear-resistant also good.

Anchor clamps 7 must be able to make plated body do outside the revolution towards revolution direction 9, also need to make it to do rotation towards sense of rotation 8, the more important thing is, all revolution and sense of rotation all must be changeed by clockwise direction when design, also can counterclockwise change.Thus, the thickness of the blade and the knife back be may command freely.

The back segment program of plated film, utilization nitrogen quick cooling, but do not influence adhering to of plated body matter, and it is hard to reach the surface, inner tough purpose, and shorten the processing method time.To plate the particle of material little for tool surface in addition, surface smoothing, and sticking power is good, is advantage of the present invention.Usually the film thickness of plated body matter formation can not influence the cutter apparent size at 0.5-3 μ m.

The most normal use at present generally the miniature electronic cutter material for having the superhard sintered alloy of WC (wolfram varbide), Co (cobalt), TaC (tantalum carbide) and TiC (titanium carbide).With WC (wolfram varbide) is major ingredient, adds the porcelain gold that TiC (titanium carbide), TiN (titanium nitride), TaC (tantalum carbide) and Co (cobalt) etc. are formed again, and its temperature tolerance, anti-damaged property are all better than superhard alloy.Microbit that the present invention utilized and milling cutter promptly are to utilize wolfram varbide superhard alloy and two kinds of materials of porcelain gold as ground, because coating layer is for only having the film of 0.5 μ m-3 μ m, thereby all cutting characteristics can not only rely on coating layer to keep, so the mother metal characteristic also has certain influence to the performance of cutter.

The processing method of low-temperature physics sputter coating provided by the present invention has following some advantage:

1. carry out coating under the low temperature: the program of the present invention's low-temperature physics plated film, symbolic animal of the birth year is to subzero treatment (120 ℃-400 ℃), can avoid Yin Gaowen and cause plating thing toughness reducing, add plated film after cutter have the above hardness of twice, tack and wearability all can increase.In the case, in the coating during other various element, its sticking power is better again, under normal conditions, also can not be subjected to influencing and produce the phenomenon that comes off in the atmosphere.

2. use ion auxiliary: the minitype ion that arc gum is up to, cooperate ion gun auxiliary again, with its more tiny ionising treatment and give bigger kinetic energy of trying again, because ion is more tiny, easier adhering to, simultaneously easilier needs the element ion compatibility of coating and form unbreakable multielement film with other, the surface smoothness height, the hardness height, good attachment, density are also high.

3. guiding heat radiation: the present invention holds heat radiation with thermal steering to plated body, just do not cut the heat radiation of function part at cutter, can avoid the tip of cutter to become the divergence point of heat energy, make the plated body mother metal produce " thermal stresses " concentration phenomenon, and cause the deposits yields of plating at this plated body tool tip place to adhere to bad and the phenomenon of demoulding is arranged.

4. applied widely: in the plated film of cutter, because of plating the material difference of thing, and the shape of cutter has the particular requirement of difference, therefore must be when plated film because of various changes in material differences, adjust in the differing temps end, add that to be cut thing also inequality, thereby cause many variablees; The present invention is directed to different material characteristics and all done the collection and the experiment of database, go for various different cutters and difference really and plating metal, have high suitability.

Coating process method provided by the invention can be coated with by multiple material.The present invention further specifies the present invention with following embodiment in addition, but does not limit spirit of the present invention and interest field.

Description of drawings

Fig. 1 is the present invention's a PVD low temperature sputtering system sketch;

Fig. 2 is the present invention's a fundamental diagram (target running synoptic diagram).

Among the figure

1 arc power

2 grid bias power supplies

3 triggering devices

4 targets

5 reactant gasess

6 pumps (diffusion pump and mechanical pump)

7 anchor clamps

8 anchor clamps senses of rotation

9 work hanger revolution directions

10 anodes

11 metal ions

12 evaporated metal atoms

13 filtering nets

14 electricity slurry districts

15 ion guns

16 little drops

Embodiment

Embodiment one

Plated body is a mini milling cutter, and the mother metal of mini milling cutter is a wolfram varbide porcelain gold, shank diameter 3.175mm, and blade diameter 1.0mm, effective long 5mm of sword, the target that processing method is selected for use is Zr, Hf alloy, the service temperature of carrying out overlay film is 250 ℃-400 ℃.

Plated film finishes after ultimate analysis contains the 71wt% zirconium, the 9wt% hafnium, and 8wt% carbon, and 12wt% nitrogen, the thickness of plated film film is 2 μ m and 3 μ m.Uncoated milling cutter base material dimension Ke Shi hardness is 2100 (Hv10g), milling cutter dimension Ke Shi hardness behind the plated film is 4500 (Hv10g), its apparent size is constant, the thickness that actual test is generally used with the circuit card industry is implemented cutting as 1.6mm FR (glass fiber rubber)-4 as substrate, resultant cutter life (unit: meter) test data as shown in Table 1, it is original more than 3 times to learn that the ZrHfCN plated film can be increased to the milling cutter life-span:

The milling cutter sample	Plated film not	ZrHfCN plated film 2 μ m	ZrHfCN plated film 3 μ m
				????1	????19	????48	????54
????2	????16	????53	????45
				????3	????21	????47	????66
????4	????14	????56	????51

Table one: milling cutter life test table

Embodiment two

Plated body is a mini milling cutter, and the mother metal of mini milling cutter is a wolfram varbide sintering superhard alloy, shank diameter 3.175mm, and blade diameter 1.5mm, effective long 8mm of sword, the target that processing method is selected for use is Zr, Hf alloy, the service temperature of carrying out overlay film is 210 ℃-390 ℃.

Plated film finishes after ultimate analysis contains the 76wt% zirconium, the 4wt% hafnium, and 9wt% carbon, and 11wt% nitrogen, the thickness of plated film film is 1.2 μ m-2.8 μ m.Uncoated milling cutter base material dimension Ke Shi hardness is 1970 (Hv10g), milling cutter dimension Ke Shi hardness behind the plated film is 4250 (Hv10g), its apparent size is constant, actual test is that substrate is implemented cutting with thickness for 1.6mm FR-4, and with the U board of obtaining on the market not the plated film milling cutter do one relatively, resultant cutter life (unit: meter) test data can learn that the ZrHfCN plated film can be increased to the milling cutter life-span original 1.5-3 doubly as shown in Table 2:

The milling cutter sample	The U board is the plated film milling cutter not	This tests not plated film milling cutter	This experiment ZrHfCN plated film milling cutter
				??1	?29	??41	??89
??2	?36	??52	??74
				??3	?25	??45	??83
??4	?34	??46	??96

Table two: milling cutter life test table

Embodiment three

Plated body is a microbit, and the mother metal of mini milling cutter is a wolfram varbide porcelain gold, and shank diameter 3.175mm bores tail diameter 0.3mm, useful length 5.5mm, and coatings is the ZrCN film, the service temperature of carrying out overlay film is 120 ℃-280 ℃.

The thickness of plated film film is 0.5 μ m-2.2 μ m.Uncoated drill bit base material dimension Ke Shi hardness is 2050 (Hv10g), drill bit dimension Ke Shi hardness behind the plated film is 4170 (Hv10g), its apparent size is constant, actual borehole test is that substrate is implemented boring with the FR-4 that to contain 8 layers of 1/2 ounce of total thickness of Copper Foil be 1.6mm, boring rotating speed 120krpm, feed speed 6m/min, compare plated film drill bit and plated film drill bit boring tolerance range between the two not and repeatability, it represents Cpk value (the Capable Process capability indices of numerical value for statistics some amount data, the processing method Capability index: high more person is good more for numerical value), test data is divided into the Cpk calculated value in continuous brill 6000 holes and 9000 holes, and test result as shown in Table 3.Can learn drill bit behind the plated film than plated film person Cpk value is high, promptly represent with the resulting pore distribution of plated film bit bore near central point and comparatively concentrated, so its processing quality and also greatly raising accuracy life.

The microbit sample	The boring number	Plated film drill bit not	The plated film drill bit
				????1	6000 holes	????1.186	????1.802
9000 holes	????0.935	????1.686
			????2		6000 holes	????1.249	????1.817
9000 holes	????1.140	????1.664
				????3	6000 holes	????1.532	????1.767
9000 holes	????1.296	????1.411

Table three: the Cpk value of microbit borehole test

Though the present invention with three preferred embodiments openly as above; right its is not in order to limit the present invention; anyly have the knack of this skill person; without departing from the spirit and scope of the invention; when can doing a little change and retouching, so the present invention's protection domain attached claims person of defining after looking is as the criterion.

Claims (5)

1. one kind is used for the processing method that coating ZrHfCN superhard wear decreases film on the miniature cutting tool, it is characterized in that:

A. load plated body in anchor clamps, clean and dry;

B. load these anchor clamps in vacuum oven, vacuumize, heat to 120 ℃-400 ℃;

C. utilize ion to clean this plated body surface;

D. carry out plated film: carry out surperficial coating with the low-temperature physics vapour deposition process, and the ion that utilizes ion supplementary unit and filtering net refinement to get from target;

E. feed reactant gases;

F. use nitrogen cooling plated body.

2. as claimed in claim 1 on miniature cutting tool the processing method of coating ZrHfCN film, it is characterized in that this plated body is that miniature cutting tool is microbit and the milling cutter of shank diameter less than 4mm, the mother metal of this miniature cutting tool is wolfram varbide sintered alloy or wolfram varbide porcelain gold.

3. the processing method that the coating superhard wear decreases film on miniature cutting tool as claimed in claim 1, what it is characterized in that this film consists of ZrCN or ZrHfCN, and wherein the Hf weight percent is 0-10%.

4. the processing method that coating ZrHfCN superhard wear decreases film on miniature cutting tool as claimed in claim 3, the thickness that it is characterized in that this film is 0.5-3 μ m.

5. as claimed in claim 1 on miniature cutting tool the processing method of coating ZrHfCN film, it is characterized in that this reactant gases is methane (CH4) or acetylene (C2H2) or propane (C3H8) and the mixed gas of nitrogen.

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