CN1974870A - Supersonic method of lowering internal stress of electroplated copper film - Google Patents
Supersonic method of lowering internal stress of electroplated copper film Download PDFInfo
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- CN1974870A CN1974870A CN 200610118667 CN200610118667A CN1974870A CN 1974870 A CN1974870 A CN 1974870A CN 200610118667 CN200610118667 CN 200610118667 CN 200610118667 A CN200610118667 A CN 200610118667A CN 1974870 A CN1974870 A CN 1974870A
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Abstract
The present invention relates to material technology, and is especially supersonic method of lowering internal stress of electroplated copper film. Through compounding electroplating solution, setting the electroplating bath inside with electroplating solution one supersonic bath, and electroplating for time depending on the thickness of the electroplated copper film in the electroplating solution temperature controlled in 30-35 deg.c and the current density of 4-16 A/sq dm, electroplated copper film is prepared. It is shown by means of X-ray diffraction measurement that the supersonic effect can reduce the internal stress of electroplated copper film effectively.
Description
Technical field
What the present invention relates to is the method in a kind of material technology field, specifically is the method that a kind of ultrasonic wave reduces internal stress of electroplated copper film.
Background technology
Copper electroplating layer has purposes widely, and as internal layer, copper coating can be and obtains the serial serving that conforms to quality requirements and reduce production costs to give security; Copper coating has good conductive capability and is applied in the electronic industry.But in electroplating process, can relate to problem about coating stress.Most of metal plating have internal stress, and the internal stress of coating usually causes matrix distortion, and self cracks coating, even coating are peeled off come off, not only lost the function of coating, also can exert an adverse impact to matrix.The method of reduction at present or elimination coating internal stress mainly contains: the type and the interior state thereof that change body material; Adjust voltage or current density when electroplating; Regulate workpiece and bath temperature; Select suitable bath composition and electroplate after thermal treatment etc.But these methods in specific implementation process more or less exist some limitation.For example: body material can't arbitrarily change; Require arbitrarily to adjust the component of some electroplating technological parameter and plating bath etc. according to processing requirement and coating performance.
In recent years, because ultrasonic device is universal, ultrasonic wave has obtained application in electroplating technology.It has mainly acted on: (1) cleanup action: powerful shockwave porous thoroughly cleans electrode surface in different electrode dielectric surfaces and space.(2) liberation of hydrogen effect: often be mixed with the generation of hydrogen in the plating, the hydrogen that is clipped in the coating reduces coating performance, and the hydrogen of overflowing causes piebald and striped easily, and ultrasonic cavitation makes hydrogen enter cavitation bubble or as cavitation nucleus, accelerated separating out of hydrogen.(3) stirring action: the high-speed micro-jet that ultrasonic cavitation produced has been strengthened the stirring action of solution, has strengthened the ionic transportcapacity, has reduced dispersion layer thickness and concentration gradient, has reduced the solution polarization, has accelerated electrode process, has optimized electroplating manipulation condition.
Find by prior art documents, people such as F.Touveras are at " UltrasonicsSonochemistry " (sonochemistry) (2005, Vol.12, No.1-2, p13-15) deliver in the paper of " Effectsof ultrasonic irradiation on the properties of coatings obtained by electroless platingand electroplating " (ultrasonication is to electroless plating and galvanization coating Effect on Performance) and mention the influence of ultrasonication electronickelling film internal stress, this article result of study shows that in ultrasonic frequency be under the condition of 500kHz, and ultrasonication can reduce the internal stress of electronickelling film.Its shortcoming is: use high frequency ultrasound, higher to equipment requirements, common ultrasonic bath equipment is difficult to reach this requirement.In further retrieving, find as yet to utilize common low frequency ultrasound bath equipment to reduce the relevant report of internal stress of electroplated copper film.
Summary of the invention
The objective of the invention is at the deficiencies in the prior art, provide a kind of ultrasonic wave to reduce the method for internal stress of electroplated copper film.The present invention by in electroplating process in conjunction with ultrasonic technology, realize reducing internal stress of electroplated copper film, do not need to adjust electroplating technology and electroplate liquid component, base material and state thereof are not had particular requirement, can also improve the electroplated copper film quality simultaneously.
The present invention is achieved through the following technical solutions, method is as follows: at first prepare electroplating solution, the plating tank that fills electroplating solution is positioned in the ultrasonic bath, and the temperature and the current density of control electroplating solution are by changing the electroplated copper film that electroplating time obtains different thickness.The present invention is positioned over plating tank in the ultrasonic bath on the basis that does not change original copper plating process, utilizes ultrasonication to reduce the internal stress of electroplated copper film.Utilize the X-ray diffraction technology that the film internal stress is measured.
Described electroplating solution adopts any one in following two kinds:
First kind, for not containing the common copper sulfate acid electroplating solution of any additives, electroplating solution comprises copper sulfate and two kinds of components of sulfuric acid, and wherein each components contents is: contain 100 gram copper sulfate and 100 gram sulfuric acid in 1 liter of electroplating solution;
Second kind, for comprising the copper sulfate electroplate liquid of two kinds of additives, its component is: electroplating solution comprises copper sulfate, sulfuric acid, thiocarbamide and polyoxyethylene glycol, and wherein each components contents is: contain 100 gram copper sulfate, 100 gram sulfuric acid, 2 gram thiocarbamides and 2 gram polyoxyethylene glycol in 1 liter of electroplating solution.
The temperature of described electroplating solution generally is controlled between 30-35 degree centigrade.It should be noted: the fluidic coupling in the ultrasonic procedure around the reaction vessels increases temperature, so will control temperature in electroplating process, makes it satisfy processing requirement.Concrete grammar is: utilize the water vent of ultrasonic bath that water is discharged, the water that will be lower than 25 degrees centigrade simultaneously imports in the ultrasonic bath, and temperature drops to 30 degrees centigrade in ultrasonic bath.
Described current density generally is controlled at 4A/dm
2-16A/dm
2Between.The variation of current density can cause the formation of electroplated copper film different orientation texture, when current density less than 6A/dm
2At present mainly form the silk weaving structure of (220) orientation, when current density greater than 10A/dm
2The main down silk weaving structure that forms (111) orientation.The generation of texture can influence the accuracy of X-ray diffraction method to the film internal stress measuring, when current density is 8A/dm
2The time, electroplated copper film texture a little less than, can guarantee the reliability of internal stress measuring.
Described electroplated copper film adopts in two kinds of materials any one as substrate: aluminum alloy substrate or Ni-P amorphous substrate.Aluminum alloy substrate is carried out oil removing, deoxidation layer and activation treatment before plating.The Ni-P amorphous substrate is that the layer thickness with the electric plating method preparation surpasses 15 microns Ni-P amorphous deposit on copper sheet.
Described ultrasonic bath, ultrasonic power are 120W, operating frequency 40kHz.Ultrasonic bath belongs to indirect ultrasonication, and is more convenient and cheap, and pollution-free to reaction soln.In ultrasonic procedure, require the liquid level of ultra sonic bath trough inner water liquid level a little more than electroplating solution in the plating tank.
The control of described electroplating time mainly is in order to obtain the electroplated copper film of different thickness, and the long more film of electroplating time is thick more.In order to obtain the electroplated copper film of different thickness, electroplating time was respectively 2-60 minute, and film thickness is between the 2-60 micron.
The high-speed micro-jet that the present invention utilizes ultrasonic cavitation to produce to the shock action of copper electrolytic coating, is relaxed the internal stress of electroplated copper film in electroplating process, has reduced the internal stress of copper coating.The method of reduction in the past or elimination coating internal stress need be adjusted the component of electroplating solution usually, perhaps changes base material.Advantage of method provided by the present invention is, under the situation of component that need not change electroplating solution and base material, just can reach the purpose that reduces the copper coating internal stress.Another advantage of the present invention is that ultrasonic power is 120W, and ultrasonic frequency is 40kHz, uses common ultrasonic cleaning apparatus just can reach above-mentioned technical requirements, does not need specific equipment.
Description of drawings
Fig. 1. have silk weaving structure feature copper membrane stress and measure 2 θ-sin2 ψ relation curve
Fig. 2. different thickness copper film internal stress measuring result (example 1)
Fig. 3. different thickness copper film internal stress measuring result (example 2)
Fig. 4. different thickness copper film internal stress measuring result (example 3)
Fig. 5. different thickness copper film internal stress measuring result (example 4)
Fig. 6. different thickness copper film internal stress measuring result (example 5)
Embodiment
Below embodiments of the invention are elaborated: present embodiment has provided detailed embodiment and process being to implement under the prerequisite with the technical solution of the present invention, but protection scope of the present invention is not limited to following embodiment.
Example 1
Preparation contains 100 gm/litre copper sulphate and 100 grams per liter vitriolic electroplating solutions, does not add any additives.The plating tank that will contain 500 milliliters of electroplating solutions is positioned in the ultrasonic bath, and ultrasonic power is 120W, operating frequency 40kHz, and ultra sonic bath trough inner water liquid level is a little more than the liquid level of electroplating solution in the plating tank.Anode is a copper sheet, and substrate is an aluminium alloy, and temperature is controlled at 30-35 degree centigrade, and current density is 8A/dm
2Electroplating time was respectively 2,5,10,30,60 minutes, obtained the copper coating that thickness is respectively 2,8,15,30,60 micron thickness, and this coating is the brick-red of half light, no burr, defectives such as bulge.The concrete grammar of bath temperature control is: utilize the water vent of ultrasonic bath that water is discharged, the water that will be lower than 25 degrees centigrade simultaneously again imports in the ultrasonic bath, and temperature drops to 30 degrees centigrade in ultrasonic bath.Utilize the method for X-ray diffraction to measure the internal stress of electroplated copper film, Fig. 1 is for being 8A/dm in current density
22 θ-the sin of its internal stress measuring of copper film for preparing under the condition
2ψ relation curve, 2 θ-sin as shown in the figure
2ψ has good linear relationship, satisfies the internal stress measuring requirement.Fig. 2 is different thickness copper film internal stress measuring result.Compare with the electroplated copper film that does not add the ultrasonication preparation, the film internal stress has tangible reduction.The copper film internal stress of 30 micron thickness is reduced to 51MPa from 109MPa, and the copper film internal stress of 60 micron thickness is reduced to 58MPa from 124MPa.
Example 2
Preparation contains 100 gm/litre copper sulphate, 100 grams per liter sulfuric acid, the electroplating solution of 2 grams per liter thiocarbamides and 2 grams per liter polyoxyethylene glycol.The plating tank that will contain 500 milliliters of electroplating solutions is positioned in the ultrasonic bath, and ultrasonic power is 120W, operating frequency 40kHz, and ultra sonic bath trough inner water liquid level is a little more than the liquid level of electroplating solution in the plating tank.Anode is a copper sheet, and substrate is an aluminium alloy, and temperature is controlled at 30-35 degree centigrade, and current density is 8A/dm
2Electroplating time was respectively 2,5,10,30,60 minutes, obtained the copper coating of 3,8,14,32,57 micron thickness, and this coating presents preferred metal gloss, no burr, defectives such as bulge.The method of bath temperature control is with described in the example 1.Fig. 3 is different thickness copper film internal stress measuring result.Compare with the electroplated copper film that does not add the ultrasonication preparation, the film internal stress has tangible reduction.The copper film internal stress of 32 micron thickness drops to 50 MPas from 104 MPas, and the copper film internal stress of 57 micron thickness drops to 54 MPas from 113 MPas.
Example 3
Preparation contains 100 gm/litre copper sulphate and 100 grams per liter vitriolic electroplating solutions, does not add any additives.The plating tank that will contain 500 milliliters of electroplating solutions is positioned in the ultrasonic bath, and ultrasonic power is 120W, operating frequency 40kHz, and ultra sonic bath trough inner water liquid level is a little more than the liquid level of electroplating solution in the plating tank.Anode is a copper sheet, and substrate is the Ni-P amorphous deposit, and temperature is controlled at 30-35 degree centigrade, and current density is 8A/dm
2Electroplating time was respectively 2,5,10,30,60 minutes, obtained the copper coating of 3,11,18,26,59 micron thickness, and this coating is the brick-red of half light, no burr, defectives such as bulge.The method of bath temperature control is with described in the example 1.Fig. 4 is different thickness copper film internal stress measuring result.Compare with the electroplated copper film that does not add the ultrasonication preparation, the film internal stress has tangible reduction.The copper film internal stress of 26 micron thickness drops to 58 MPas from 118 MPas, and the copper film internal stress of 59 micron thickness drops to 55 MPas from 127 MPas.
Comparison example 1-3 adds thiocarbamide and polyoxyethylene glycol simultaneously in common copper sulfate copper facing electroplating solution, or changes under the situation of base type, and the ultrasonic wave effect all helps to reduce the internal stress of acid copper sulfate electroplated copper film.
Example 4
Preparation contains 100 gm/litre copper sulphate and 100 grams per liter vitriolic electroplating solutions, does not add any additives.The plating tank that will contain 500 milliliters of electroplating solutions is positioned in the ultrasonic bath, and ultrasonic power is 120W, operating frequency 40kHz, and ultra sonic bath trough inner water liquid level is a little more than the liquid level of electroplating solution in the plating tank.Anode is a copper sheet, and substrate is the Ni-P amorphous deposit, and temperature is controlled at 30-35 degree centigrade, and current density is 4A/dm
2Electroplating time was respectively 10,30,60 minutes, obtained the copper coating of 8,15,27 micron thickness, and this coating is the brick-red of half light, no burr, defectives such as bulge.The method of bath temperature control is with described in the example 1.Fig. 5 is different thickness copper film internal stress measuring result.Compare with the electroplated copper film that does not add the ultrasonication preparation, the film internal stress has tangible reduction.The copper film internal stress of 15 micron thickness drops to 54 MPas from 79 MPas, and the copper film internal stress of 27 micron thickness drops to 63 MPas from 102 MPas.
Example 5
Preparation contains 100 gm/litre copper sulphate and 100 grams per liter vitriolic electroplating solutions, does not add any additives.The plating tank that will contain 500 milliliters of electroplating solutions is positioned in the ultrasonic bath, and ultrasonic power is 120W, operating frequency 40kHz, and ultra sonic bath trough inner water liquid level is a little more than the liquid level of electroplating solution in the plating tank.Anode is a copper sheet, and substrate is the Ni-P amorphous deposit, and temperature is controlled at 30-35 degree centigrade, and current density is 16A/dm
2Electroplating time was respectively 5,15,30 minutes, obtained the copper coating of 14,32,59 micron thickness, and this coating is the brick-red of half light, no burr, defectives such as bulge.The method of bath temperature control is with described in the example 1.Fig. 6 is different thickness copper film internal stress measuring result.Compare with the electroplated copper film that does not add the ultrasonication preparation, the film internal stress has tangible reduction.The copper film internal stress of 32 micron thickness drops to 59 MPas from 123 MPas, and the copper film internal stress of 59 micron thickness drops to 63 MPas from 130 MPas.
Comparison example 4,5 is when current density is 4A/dm
2Or 16A/dm
2The time, though there is error in the internal stress of electroplated copper film measuring result, copper film internal stress reduces apparent in view under ultrasonication as shown in the figure.
Claims (10)
1, a kind of ultrasonic wave reduces the method for internal stress of electroplated copper film, it is characterized in that, at first prepare electroplating solution, the plating tank that fills electroplating solution is positioned in the ultrasonic bath, the temperature and the current density of control electroplating solution, by changing the electroplated copper film that electroplating time obtains respective thickness, wherein: the temperature of control electroplating solution is between 30-35 degree centigrade, and current density is at 4-16A/dm
2Between.
2, ultrasonic wave according to claim 1 reduces the method for internal stress of electroplated copper film, it is characterized in that, described electroplating solution, be common copper sulfate acid electroplating solution, electroplating solution comprises copper sulfate and two kinds of components of sulfuric acid, and wherein each components contents is: contain 100 gram copper sulfate and 100 gram sulfuric acid in 1 liter of electroplating solution.
3, ultrasonic wave according to claim 1 reduces the method for internal stress of electroplated copper film, it is characterized in that, described electroplating solution, for comprising the copper sulfate electroplate liquid of two kinds of additives, its component is: electroplating solution comprises copper sulfate, sulfuric acid, thiocarbamide and polyoxyethylene glycol, and wherein each components contents is: contain 100 gram copper sulfate, 100 gram sulfuric acid, 2 gram thiocarbamides and 2 gram polyoxyethylene glycol in 1 liter of electroplating solution.
4, ultrasonic wave according to claim 1 reduces the method for internal stress of electroplated copper film, it is characterized in that, the temperature of described control electroplating solution, method is: utilize the water vent of ultrasonic bath that water is discharged, the water that will be lower than 25 degrees centigrade simultaneously imports in the ultrasonic bath, and temperature drops to 30 degrees centigrade in ultrasonic bath.
5, ultrasonic wave according to claim 1 reduces the method for internal stress of electroplated copper film, it is characterized in that described current density is 8A/dm
2
6, ultrasonic wave according to claim 1 reduces the method for internal stress of electroplated copper film, it is characterized in that described electroplated copper film adopts aluminum alloy substrate or Ni-P amorphous substrate.
7, ultrasonic wave according to claim 6 reduces the method for internal stress of electroplated copper film, it is characterized in that described aluminum alloy substrate is carried out oil removing, deoxidation layer and activation treatment before plating.
8, ultrasonic wave according to claim 6 reduces the method for internal stress of electroplated copper film, it is characterized in that described Ni-P amorphous substrate is that the layer thickness with the electric plating method preparation surpasses 15 microns Ni-P amorphous deposit on copper sheet.
9, ultrasonic wave according to claim 1 reduces the method for internal stress of electroplated copper film, it is characterized in that, and described ultrasonic bath, ultrasonic power is 120W, operating frequency 40kHz.
10, ultrasonic wave according to claim 1 reduces the method for internal stress of electroplated copper film, it is characterized in that described electroplating time is 2-60 minute.
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| CN102409377A (en) * | 2011-11-23 | 2012-04-11 | 江苏大学 | Method and device for manufacturing copper/aluminum compound conductive bar by plating |
| CN102811830A (en) * | 2010-03-31 | 2012-12-05 | Jx日矿日石金属株式会社 | Fine silver-plated copper powder and method for producing same |
| CN102858087A (en) * | 2012-08-27 | 2013-01-02 | 吴祖 | Blind-hole-conduction double-sided circuit board and processing method thereof |
| CN104818503A (en) * | 2015-04-15 | 2015-08-05 | 同济大学 | Preparation method of porous copper full-impregnated film of three-dimensional network structure |
| CN106544704A (en) * | 2016-11-03 | 2017-03-29 | 山东金宝电子股份有限公司 | A kind of preparation method of low warpage Copper Foil |
| CN110592622A (en) * | 2019-10-10 | 2019-12-20 | 江苏科技大学 | Ultrasonic potential activation method for improving bonding strength of electroforming metal film substrate interface |
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2006
- 2006-11-23 CN CN 200610118667 patent/CN1974870A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN102811830A (en) * | 2010-03-31 | 2012-12-05 | Jx日矿日石金属株式会社 | Fine silver-plated copper powder and method for producing same |
| CN102409377A (en) * | 2011-11-23 | 2012-04-11 | 江苏大学 | Method and device for manufacturing copper/aluminum compound conductive bar by plating |
| CN102858087A (en) * | 2012-08-27 | 2013-01-02 | 吴祖 | Blind-hole-conduction double-sided circuit board and processing method thereof |
| CN104818503A (en) * | 2015-04-15 | 2015-08-05 | 同济大学 | Preparation method of porous copper full-impregnated film of three-dimensional network structure |
| CN106544704A (en) * | 2016-11-03 | 2017-03-29 | 山东金宝电子股份有限公司 | A kind of preparation method of low warpage Copper Foil |
| CN110592622A (en) * | 2019-10-10 | 2019-12-20 | 江苏科技大学 | Ultrasonic potential activation method for improving bonding strength of electroforming metal film substrate interface |
| CN110592622B (en) * | 2019-10-10 | 2020-10-16 | 江苏科技大学 | Ultrasonic potential activation method for improving bonding strength of electroforming metal film substrate interface |
| EP4234768A4 (en) * | 2021-09-10 | 2024-05-08 | Contemporary Amperex Technology Co., Limited | Electrolytic copper foil and preparation method therefor, negative electrode plate, secondary battery, battery module, battery pack, and electric device |
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