Effect of Different Pretreatment Processes on ABS Resin Surface on Electroless Copper Plating

Transcription

1 RESEARCH ARTICLE Effect of Different Pretreatment Processes on ABS Resin Surface on Electroless Copper Plating Jiushuai Xu School of Science, Northwest A&F University Abstract: The surface of ABS resin was pretreated by different pre-treatment processes such as polishing, lye cleaning or corona discharge treatment, and then 6-(3-triethoxy) was prepared on the surface of different pretreated ABS resin by self-assembly technique. Silicone propyl) ammonia-1,3,5-triazine-2,4-dithiol monosodium salt (TES) film was subjected to electroless copper plating. The surface state of ABS resin and the surface appearance after electroless copper plating were characterized by contact angle measuring instrument, scanning electron microscope (SEM) and adhesion test. The results show that the surface contact angle of the ABS resin after corona discharge treatment is 46.3 compared with the surface of the ABS resin after the lye cleaning and polishing treatment, and the hydrophilicity is good, which is beneficial to the surface of the ABS resin. Formation of a silane self-assembled film. The results of electroless copper plating show that the copper layer formed on the surface of the polished ABS resin has poor uniformity and large copper particles; the copper layer prepared on the surface after alkali treatment is dense and uniform, but easy to fall off; the surface after corona treatment The copper layer is dense and uniform, and the copper particles are small and have good connectivity to the substrate. Keywords:ABS resin; pretreatment; heterocyclic silane; self-assembled film; electroless copper plating 1. Introduction Metallization of the plastic surface allows it to maintain the properties of plastics such as heat resistance and processability, as well as the electrical conductivity and magnetic permeability of the metal. The surface-metallized plastic products have high mechanical strength, light weight and long service life, which further expands their application fields [1], such as in the electronics industry, electrical accessories, automotive interior and exterior parts and interior decoration [2] and other fields. ABS plastic is one of the most widely used and widely used polymers. It has excellent impact resistance, heat resistance, low temperature resistance, chemical resistance and electrical properties. It is also easy to process, stable in size and good in surface gloss. It is easy to apply and color, and is an ideal material for metallization. Pretreatment of plastic surfaces is one of the key factors in surface metallization. It is necessary to form the best roughness on the surface and introduce atoms or groups that can coordinate with Cu, such as N, S, aromatic rings, etc. Electroless copper plating proceeds smoothly, so the quality of the pretreatment determines the copper plating effect of the plastic surface to a certain extent [3]. At present, the roughening process of plastic surface is often treated with potassium permanganate [3], chromic acid [4], H2SO4-MnO2 [5], polyacrylic acid [6-7], etc., which is complicated in operation and harmful to the environment and human body.. Recently, a functional self-assembled nanofilm with special functional groups was introduced after pretreatment of the plastic surface to increase the complexing force between the plastic and the metal [8], thereby obtaining a strong adhesion. The electroless copper plating layer is plastic. An effective way of surface metallization [9]. The self-assembled monomolecular film layer has a highly ordered characteristic, and a specific group can be introduced at the end of the alkyl chain of the molecular layer, thereby Copyright 2018 Jiushuai Xu. doi: /mmst.v1i1. This is an open-access article distributed under the terms of the Creative Commons Attribution Unported License ( which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Modern Materials Science and Technology Volume 1 Issue

2 changing characteristics such as etching [10], wetting [11] of the surface of the material. At the same time, the introduction of a self-assembled monomolecular film with a functional functional group on the surface of the plastic avoids the environmental pollution problem caused by the above conventional treatment method, and is an environmentally friendly and effective surface treatment method. In this paper, ABS resin is used as the object. Firstly, it is pretreated by polishing agent, lye cleaning or corona discharge. Then, 6-(3-triethoxysilylpropyl) is prepared on the surface of different pretreated ABS resin. Amino-1,3,5-triazine-2,4-dithiol monosodium salt (TES) self-assembled film, and finally electroless copper plating. The surface conditions of different pretreated ABS resins and the surface appearance after electroless copper plating were analyzed by contact angle measuring instrument, scanning electron microscope (SEM) and cross-cutting experiment to determine the optimum pretreatment conditions for ABS resin surface. 2. Experiment 2.1 Experimental reagents and materials The reagents used in the experiment were absolute ethanol (analytical grade); sodium carbonate (anhydrous, analytical grade); trisodium phosphate (analytical grade); metallographic polishing agent (2.5 μm, Wuhan Sanling); 37% (mass fraction) hydrochloric acid Stannous chloride (analytical grade); palladium chloride (Pd 60%); copper sulfate pentahydrate (analytical grade); sodium potassium tartrate (analytical grade); ammonium chloride (analytical grade); formaldehyde (analytical grade) Sodium chloride (analytical grade); sodium hydroxide (analytical grade). TES (Fig. 1) is self-made in the laboratory. It is first reacted with cyanuric chloride with 3-aminopropyltriethoxysilane to form 6-(3-aminopropyltriethoxy)silane-1,3,5- Triazine-2,4-dichloro is then reacted with anhydrous sodium hydrosulfide to give TES [12]. The material used in the experiment was ABS resin (2 cm 5 cm 1 mm). The surface grease was removed by ultrasonic cleaning for 15 min before use with absolute ethanol and dried. Then, the ABS resin sheet washed with absolute ethanol was subjected to alkali treatment, polishing agent polishing and corona discharge treatment, respectively. The lye treatment process is: placing ABS resin sheet in 40g/L sodium hydroxide, 30g/L trisodium phosphate and 20g/L anhydrous sodium carbonate mixed solution, treating at 60 C for 10min, then washing with water, alcohol washing and drying [13]. The polishing agent was sanded to evenly polish the surface of the resin with a 2.5 μm metallographic polishing agent to a flat surface. The corona discharge treatment conditions were a voltage of 50 V, a current of 2.23 A, and a discharge time of 60 s. Figure 1.Structureof6-(3-triethoxysilylpropyl)amino-1,3,5-triazine-2,4-dithiolmonosodium 2.2 Preparation of TES self-assembled film and electroless copper plating Optimization of DPC Process Applied by Electroless Copper Plating Prepare a TES solution in a 100 ml beaker, m(tes):v (deionized water): V (anhydrous ethanol) = 3 mmol/l: 5 ml: 95 ml, hydrolyze in a constant temperature water bath at 35 C for 24 h, then leave the blank ABS resin and ABS resin with different surface treatments was immersed in it, self-assembled for 30 min at 35 C, taken out and then cured in an oven at 90 C for 30 min, washed successively with deionized water, absolute ethanol, and dried to obtain a TES 2 Jiushuai Xu. Modern Materials Science and Technology

3 self-assembled film. ABS resin surface Electroless copper plating Using sensitization activation one-step method [14], treatment in 45 C activation solution for 3 min, activation solution composition of 10g / L SnCI2 2H2O, 0.1g / LPdCI2, with 37% (mass fraction) hydrochloric acid to adjust the ph value of 2, with 3.7% hydrochloric acid solution was degummed for 30 s. The electroless copper plating parameters [13] were 16 g/l CuSO4 5H2O, 25 ml/l HCHO, 25 g/l sodium potassium tartrate, 2 g/l NH4CI, the plating temperature was 55 C, the electroless plating time was 10 min, and the ph value was Determination and characterization The surface of the ABS resin electroless copper plating sample after different pre-treatment and self-assembly of TES film was cut into 1 mm 1 mm small cells with a single-sided blade, and then peeled off with polyimide tape for 1 h, and then peeled off to observe the peeling condition. The ratio of the number of undivided cells to the total number of cells is used to calculate the pass rate. The amount of electroless copper plating on the surface of ABS resin was determined by the difference in the quality of the resin sheet before and after electroless plating. The contact angle of distilled water on the surface of different samples was measured using a SL100 series static contact angle meter. The average value of each sample was measured at 3 points, and the volume of distilled water used was 1 μl. The surface morphology of the TES self-assembled film and the electroless copper plating layer was observed by a scanning electron microscope (JSM-6360LV, JEOL), and the acceleration voltage was 15 kv. 3. Results and discussion 3.1 Effect of pretreatment on surface contact angle and amount of electroless copper plating In this paper, the surface wettability of ABS resin after three different pretreatments was measured by static contact angle meter. The results are shown in Fig. 2. It can be seen from Fig. 2 that before the self-assembly of the TES film, the surface contact angles of the ABS resin surface after different pretreatments are as follows: blank (97.5 )> alkali treatment (92.1 )> sanding treatment (75.5 ) > Corona discharge treatment (46.3 ). This indicates that the surface of the ABS resin treated by corona discharge forms hydroxyl and carboxyl polar functional groups [4], so that the surface of the ABS resin exhibits good hydrophilicity, which provides a position for condensation reaction of the TES compound after hydrolysis. Point, so that a dense TES self-assembled film can be formed on the surface of the ABS resin; the contact angle of the surface of the ABS resin after alkali treatment is slightly lower than that of the blank, and it can be inferred that there is a little hydrophilic group on the surface of the ABS. The formation of the surface contact angle after polishing treatment is more, indicating that the surface roughness of the polishing agent after grinding is increased, but there is no reactive hydrophilic functional group, and the uneven structure is favorable for physical interaction with the electroless copper plating layer. Engagement. After self-assembling the TES film on the surface of different pretreated ABS resins, the surface contact angles were 82.5, 77.2, 71.9 and 85.1, respectively. The outwardly aligned groups of the TES film formed by self-assembly on the surface of the different pretreated ABS resin are thiol ( SH) functional groups, and the smaller the surface contact angle of the ABS resin covered by the TES self-assembled film, indicating that the thiol functional group is contained. The more, the more favorable the formation of the electroless copper plating layer. Therefore, compared with the alkali treatment and the sanding treatment, it is inferred that the surface electroless copper plating effect of the ABS resin after the corona discharge treatment is better. Modern Materials Science and Technology Volume 1 Issue

4 Figure 2.Effectofthedifferentpretreatmentonthecon-tactangleofABSResinsurface Figure 3.Effectofthedifferentpretreatmentonthecop-perplatingofABSResinsurface By comparing the quality of copper plating on ABS resin, it can be found that the ABS resin (blank) without self-assembled film has the largest increase in copper plating amount and the copper layer has the largest thickness; the ABS resin assembled with TES but not pretreated has the lowest copper plating quality. The thickness of the copper layer is the smallest; after several parallel experiments, it is found that the surface copper content of the polished ABS resin has poor stability, ranging from 8.0 to 30.0 mg (the data in Figure 3 is the average of multiple experiments), corona discharge treatment The quality of the copper plating layer obtained afterwards is stable, the mass is generally 12.0 to 14.0 mg, and the thickness of the copper layer is in the range of 1.32 to 1.54 μm. 3.2 Surface appearance analysis 4 is a scanning electron micrograph of the surface of the ABS resin of the blank ABS resin, the self-assembled TES film, and the ABS resin of the self-assembled TES film after the corona discharge treatment. It can be seen from Fig. 4(a) and (b) that there is no significant change in the surface appearance of the ABS resin before and after the self-assembled TES film, indicating that the surface of the untreated ABS resin is difficult to combine with the hydrolyzed TES molecule due to the lack of reactive functional groups. A self-assembled film is formed; however, as can be seen from Fig. 4(c), the surface of the ABS resin of the self-assembled TES film after corona discharge treatment exhibits a large number of pore-like structures composed of cavities, while the surface appearance around the pore-like structure Uniform continuous distribution, indicating that the polar group formed on the surface after corona discharge treatment reacted with the silanol groups in the TES molecule to form a uniform continuous TES self-assembled film. The outwardly aligned sulfhydryl groups in the film enhance the coordination ability with the electroless copper plating layer, and the cavity-like pore structure on the surface increases the roughness of the ABS resin, and also contributes to the adhesion of the electroless copper plating layer to the substrate material. The surface appearance of the 4 Jiushuai Xu. Modern Materials Science and Technology

5 self-assembled TES film on the ABS surface treated with alkali treatment and sanding is not significantly different from that in Fig. 4(b), indicating that the two pretreatment methods cannot effectively activate the surface of the ABS resin, which is not conducive to the self-assembled film in it. The formation of the surface. Figure 5 shows the surface appearance of electroless copper plating after self-assembly of TES film on different pretreated ABS resin surfaces. Figure 4.SEMimagesoftheABSresinsurface Figure 5.SEMimagesofthedifferentpretreatedABSresinsurfaceaftercoPperplating The surface of the blank ABS resin is directly electroless copper plated (Fig. 5(a)), the surface is uneven, and the copper layer particles formed on the surface are too large; compared with Fig. 5(a), the surface chemistry of the blank ABS resin after self-assembly of the TES film The surface of the copper plating is slightly smaller, but the overall distribution is still uneven (Fig. 5(b)); the alkali-treated copper plating with the TES self-assembled film as the carrier, the copper particles are further reduced, but the particle size is not equal. The distribution is very uneven; the results of electroless copper plating with TES as the carrier are similar to those of the copper after alkali treatment. Some places are rough, the particles are large, some areas are relatively flat, the particles are small; corona treated The surface of the electroless copper plating layer on the surface of the ABS resin self-assembled TES film is flat and has a good metallic luster. The copper particles are fine and uniform, densely arranged, and have a high coverage on the surface of the ABS resin. The above analysis shows that the surface of the ABS resin treated by corona discharge is fully activated, forming a polar reactive group, which facilitates the introduction of TES molecules on the surface of the ABS resin, thereby forming a ruthenium-based self-assembled molecular layer, which is favorable for uniformity. Formation of a dense electroless copper plating layer. 3.3 Cross-hatch bonding performance test Modern Materials Science and Technology Volume 1 Issue

6 In order to further determine the binding force of the electroless copper plating layer on the surface of the ABS resin after the corona discharge treatment, it was evaluated by the cross-hatch method, and the results are shown in FIG. 6. Figure 6.AdhesiontestofcopperplatingonABSbyrulingmethod It can be seen from Fig. 6 that although the copper plating of ABS without any pretreatment is thick, the bonding property is poor, and the copper layer at the edge of the small square is lifted when the cross-cut is performed, and the copper layer is plated under the action of the polyimide tape. Almost all of the detached ABS resin directly self-assembled the electroless copper plating layer after the TES film, the naked eye can observe the obvious bubbles between the copper layer and the base material, and some copper layers fall off during the cross-cutting, the poly acyl The imide tape can completely detach the copper plating layer from the ABS resin, indicating that almost no TES self-assembled film is formed on the surface of the ABS resin which is not pretreated; the alkali-treated ABS resin copper plating layer has many patterns, and some of the pattern is peeled off when the cross-cut is performed. The tape paste can stick most of the copper film; the polished ABS copper plating layer is even and smooth overall, but some small bumps are partially stuck, indicating the combination between the polished ABS resin substrate and the 6 Jiushuai Xu. Modern Materials Science and Technology

7 electroless copper plating layer. For physical engagement. The electroless copper plating surface of the self-assembled TES film on the surface of the corona treated ABS resin was uniform and smooth, and almost no copper lattice peeled off after the cross-cut test, indicating that the surface of the corona treated ABS had sufficient roughness and polarity reactive groups. It is beneficial to the formation of TES self-assembled film, so that the strong coordination bond between the bismuth base and the electroless copper plating layer can be achieved, and the ABS substrate and the copper layer are well bonded. 4. Conclusion Corona discharge treatment can effectively activate the surface of ABS resin, increase the surface roughness of ABS, and form polar functional groups, which can improve the surface wettability and reduce the contact angle to The surface of ABS resin treated by corona discharge is successful. A TES self-assembled film was prepared. The corrugated pore structure and the strong chemical coordination of sulfur atoms in the TES self-assembled film with Cu obtained a strong electroless copper plating layer bonded to the ABS resin substrate, and the electroless copper plating layer was flat and bright, uniform and dense. References 1. MiddekeHJ.PlatingonplasticspartⅣ-electrolessmetaldeposition[J].Plating and finishing,2005,24: Xinmin Fan,Jianfei Che.Engineering plastics and their applications [M]. Beijing: Mechanical Industry Press, Dun Sun,Jianping He,Jianhua Zhou,And so on.abs plastic electroplating potassium permanganate pretreatment process [J]. Material Protection, 2009, 42: Xiaojiao Yu,Xunya Zhang,Wei Fan,And so on.abs plastic electroless copper plating process [J]. Plating and Finishing, 2007, 26: Li ZX,LiN,YinL, Etal.Anenvironment-frie ndlysur-facepretreatmentofabsresi npriortoelectroless plating [J].Electroch emsolidst,12:d92-d GarciaA,BerthelotT,VielP,Etal.Microscopicstudyofaligandinducedelectrolessplatingprocess Ontopoly-mers[J].ACSApplMaterInter,2010:2: Ruihai Li,Yajuan Gao,Yi Gu,And so on.a new method for surface modification of ABS surface electroless plating [J]. Plastics Industry, 2008, 36: YamamotoY,NishiharaH,AramakiK,Etal.Self-as-sembledlayersofalkanethiolsoncopperforprotectiona Gainstcorrosion[J].ElectrochemSoc,1993:140: Fang Wang,Haining Zhang,Jing Wang,And so on.copper plating on the surface of ABS resin with heterocyclic organosilane self-assembled film as carrier [J]. Journal of Materials Science and Engineering, 2012, 30: KumarA,BiebuyckHA,AbbottNL,Etal.Theuseofself-assembledmonolayersandaselectiveetchtogeneR-atepatte rnedgoldfeatures[j].jamchemsoc, : NuzzoRG,DuboisLH,AllaraDL.FundamentalstudiesofmicroscopicwettingonorganicsurfacEs.1.Formationand structuralcharacterizationofaself-con-sistentseriesofpolyfunctionalorganicmonolayers[j].jamchemsockets : WangF,LiYN,WangY,Etal.Self-assembledmono-layerofdesignedandsynthesizedtriazinedi ThiolsilanemoleculeasinterfacialadhesionenhancerforintegratedcirCuit[J].NanoscaleResLett,2011,6: Rongxia Zhu.ABS plastic electroless copper plating experiment [J]. University Chemistry, 2011, 26: Chang Shu,Guangrong Xie,Youlan Zhu.ABS plastic plating a full set of pre-treatment process [J]. Material Protection, 2010, 43: Modern Materials Science and Technology Volume 1 Issue