Cu 2 O deposition Process

1. Cu2O deposition Process

2. Summary • Concept presentation • Technical requirements • Process description • Advantages Rhodia Kermel

3. Cu metal layer K+ BH4- Resin Cu2O particle Plating process : Concept presentation This new technology relies on the existence of cuprous oxide (Cu2O) in the substrate, which allows the metallization of the surface. The particles of Cu2O are distributed in the resin which constitutes the substrate to be metallized at the rate of 2,5 to 10 % in volume. Its transformation into pure metal, Cu°, only operates at the surface and in the micro-holes, when exposed to the contact of a specific chemical reducing agent, a borohydride, following the global reaction :This reduction converts a discrete distribution of Cu2O particles into a continuous metallic copper layer which can be reinforced by both electroless and electrolytic processes up to the required thickness. 4 Cu2O + BH4-8 Cu° + B(OH)3 + OH - Rhodia Kermel

4. Plating process : Concept presentation Products and operation for the process application : • Cu2O particles : • pulverulent powder, can be refined, dispersed within the polymeric matrix, • cheap and usual product, • several suppliers. • Chemical treatment before the reduction to remove the superficial layer of the matrix : • to achieve high level of peel strength (see photo 1 next page), • to metallize simultaneously holes and surfaces (see photo 2 next page). • Reducing agent : mainly potassium or sodium borohydride • usual (several suppliers) and low cost (much cheaper than palladium), • easy to handle (not hazardous, in an aqueous form), • easy to use : at first sight, borohydride solution can be substituted to palladium batch in the standard process line. • Optimization to fit the wanted requirement: • concentration, size and dispersion of Cu2O particles, • chemical treatment before reducing, • reduction’s parameters. Rhodia Kermel

5. Plating process : Concept presentation Photo 1 : Interface between the substrate and the copper obtained after a chemical treatment Photo 2 : Very good peel strength continuity for the metal layer in surface and holes thanks to reduced Cu2O particles Rhodia Kermel

6. Plating process : Concept presentation PCB prototype that has been obtained through the Cu2O Plating Process Size of the conductor line : 10 µm. Rhodia Kermel

7. R 3043 14.12.81 France, USA, OEB (DE, BE, GB, IT, NL, SE, IR), Japan. Organic substrate metallization process using small filler particles of dispersed non conductive oxide R 3175 15.04.83 France, USA, OEB (DE, AT, BE, SP, FR, IR, IT, LU, NL, GB, SE, CH), Canada, Korea, Japan, Taiwan, Israel, South Africa, Australia. Metallization process of thermostable films by reducing copper oxide with borohydride followed by electrolytical deposition R 3176 15.04.83 OEB (DE, AT, BE, SP, FR, IR, IT, LU, NL, GB, SE, CH) Canada, USA, Korea, Japan, Taiwan Israel, South Africa, Australia. Electrically insulated polymeric film metallization by reducing metal oxide particles with borohydride followed by electrolytical deposition R 3193 27.05.83 France, USA, OEB (DE, AT, BE, FR, GB, IT, LU, NL, SE, CH), Spain, Canada, Taiwan, Korea, Japan. Possibility of using both isotropic metallizable polymeric substrates with low CTE and resin including metal oxide particles Plating process : Concept presentation The Cu2O plating process is protected by 6 patents covering both laser and photovia drilling Internal patent number International patent number Abstract Rhodia Kermel

8. Plating process : Concept presentation The Cu2O plating process has been developed in the eighties by Rhône Poulenc and suspended for strategic reasons in the nineties. Internal patent number International patent number Abstract R 000 99 27.07.2000 French patent deposit before international extension Compatibility of laser drilling with metallization process using reduced copper oxide with borohydride followed by electrolytical deposition R 00181 29. 12. 2000 French patent deposit before international extension Compatibility of photovia drilling with metallization process using reduced copper oxide with borohydride followed by electrolytical deposition 2001 Patents in progress Rhodia Kermel

9. Concept presentation • Technical requirements • Process description • Advantages Rhodia Kermel

10. 1 Laser drilling possibility Technical compatibility 2 3 Peel strength potentially exceeding market requirements Dielectric constant features fittingmarket requirements Plating process : Technical requirements Three requirements have been tested so far highlighting the potential of the Cu2O metallization process. Rhodia Kermel

11. Plating process : Technical requirements Cu2O particles do not hinder the laser drilling quality. Non optimized laser drilling tests for Epoxy + Cu2O Cu2O weight concentration: 60 % in volume: 10 % Source: Delta Electronic services Rhodia Kermel

12. Properties Measures on ~1,6mm laminates Epoxy Cu2O 22% (1) 3.1013 3,6.1013 Superficial resistivity (/) 5.1014 3,8.1015 Volume resistivity (/cm) 4,9 4,8 Dielectric constant Dk (1 MHz) 0,019 0,018 Dissipation factor Df (1 MHz) Plating process : Technical requirements Dielectric properties are slightly modified by the Cu2O particles and even improved in certain cases Note: (1) In weight percentage Rhodia Kermel

13. Treatment types • Treatment 1: • Permanganateor bichromate chemical treatment. • At the end of the treatment, necessity to eliminate chromium or manganese oxides thanks to hydroxylamine chlorohydrate or sulphate. • Treatment 2: • Alkaline chemical treatment in hydroalcoolic environment. • Potash: 350g; methanol/ethanol/water: 400cm3/50cm3/10cm3 • Temperature: 80°C. • Peel strength fluctuating according to parameters (epoxy type, particle size and dispersion(3) , physicals conditions,…). Plating process : Technical requirements When initial chemical surface treatments are done, peel strength potentially exceed market expectations. Surface peel strength(1) for Cu2O + epoxy kg/cm Norm(2) Treatment1 Treatment2 Notes: (1) Tests realized ten years ago(2) 1,4 kg/cm = 8 lb/inch(3) Concentration between 10% to 50% in weight percentage Sources: Kermel, Rhône Poulenc Rhodia Kermel

14. Plating process : Technical requirements With regard to peel strength, Cu2O plating process offers several potential advantages Potential advantages Very good peel strength continuity in surface and holes thanks to Cu (reduced Cu2O) Increased peel strength compared to standard epoxy thanks to Cu2O particles anchored inside the resin Kermel's plating process using Cu2O particles reduced with borohydride Peel strength level modularity through control of concentration and dispersion of Cu2O particles Recycling possibility in case of non satisfactory level of metallization Rhodia Kermel

15. Concept presentation • Technical requirements • Process description • Advantages Rhodia Kermel

16. Plating process : Description At first sight, in the SBU layer production process, minor changes should occur in major PCB makers production lines to implement the Cu2O metallization concept. Changes occur principally in 2 steps : - drilling when compared to RCC (see step 4 of the process chart), - electroless plating with a substitution of the palladium by the borohydride reduction bath (see step 5). With the Cu2O metallization concept, the number of the process steps is : - 25% less than RCC technology, - the same than liquid technology.SBU layer simplified production steps with CO2 laser drilling and with different elaborated materials is presented in the 4 next slides. Rhodia Kermel

17. Production steps Solids Liquids RCC(1) Dry film Epoxy/polyimide + Cu2O Liquid resin  Core preparation • Micro-etching • Rinsing • Black oxydation Copper line Upper core layer Dielectric  Build-up deposition (coating/lamination) Copper clad Cu2O particles • Stoving • Stacking • Pressing, heating • Disassembling/cleaning • Stoving • Stacking • Pressing, heating • Disassembling/cleaning • Coating • Drying/heating • Coating • Drying/heating  Surface treatment • Half etching • Rinsing • Surface treatment • Rinsing • Surface treatment • Rinsing • Surface treatment • Rinsing Plating process : Description SBU layer simplified production steps with CO2 laser drilling and with different elaborated materials Rhodia Kermel Note: (1) Process with window creation

18. "Laser" resin "Laser" resin • CO2 drilling • Etch back • Rinsing • CO2 drilling • Etch back • Rinsing • CO2 drilling • Etch back • Rinsing • CO2 drilling • Etch back • Rinsing Plating process : Description SBU layer simplified production steps with CO2 laser drilling and with different elaborated materials Production steps Solids Liquids RCC(1) Dry film Epoxy/polyimide + Cu2O Liquid resin à Drilling Photoresist "window" • Surface preparation • Photoresist deposit • Insulation • Development • Rinsing • Etching • Rinsing • Photoresist stripping • Copper oxydation • Rinsing Rhodia Kermel Note: (1) Process with window creation

19. Epoxy/polyimide + Cu2O Production steps Solids Liquids Copper RCC(1) Dry film Epoxy/polyimide + Cu2O Liquid resin Ä Electroless plating • Surface reduction with potassium borohydride • Rinsing Copper Palladium • Degreasing • Rinsing • Pre-catalysis • Catalysis • Activation • Degreasing • Rinsing • Pre-catalysis • Catalysis • Activation • Surface reduction with potassium borohydride • Rinsing • Degreasing • Rinsing • Pre-catalysis • Catalysis • Activation • Fastened thick chemical copper deposit • Rinsing Chemicalplating • Thin chemical copper deposit • Rinsing • Thin chemical copper deposit • Rinsing • Fastened thick chemical copper deposit • Rinsing • Thin chemical copper deposit • Rinsing ÅImage transfer Photoresist Photoresist • Surface preparation • Photoresist deposit • Insulation • Development • Rinsing • Surface preparation • Photoresist deposit • Insulation • Development • Rinsing Plating process : Description SBU layer simplified production steps with CO2 laser drilling and with different elaborated materials Switch the palladium deposit bath by a borohydride reduction bath Rhodia Kermel Note: (1) Process with window creation

20. Production steps Solids Liquids RCC(1) Dry film Epoxy/polyimide + Cu2O Liquid resin Æ Electrolytical plating • Copper deposit • Rinsing • Photoresist stripping • Rinsing • Copper deposit • Rinsing • Photoresist stripping • Rinsing Ç Etching • Etching • Rinsing • Differential etching • Rinsing • Differential etching • Rinsing • Differential etching • Rinsing Plating process : Description SBU layer simplified production steps with CO2 laser drilling and with different elaborated materials Note: (1) Process with window creation Rhodia Kermel

21. Concept presentation • Technical requirements • Process description • Advantages Rhodia Kermel

22. Plating process : Advantages This new plating process is : Easy to implement - Process gets simultaneously plated holes and surfaces. - Products are usually cost competitive and easy to handle (Cu2O and borohydride). - Number of process steps reduced. - Compatibility with liquid/film technologies. Reliable - Due to the high level of peel strength achieved. - Peel strength of plated copper increased in surface and in micro-via holes. Technologically advanced - Reliable access to additive/semi additive processes. - Reliable access to fine line. - The presence of Cu2O particles, compatible with the dielectric and CTE requirements, enhance the thermal transfer of dielectric matrix. Economic - Reliability and more specifically of plated micro-holes. - Saving of labor because of less steps and operations. - Saving of investment because minimum changes in production lines for PCB makers. Rhodia Kermel

23. Plating process : Conclusion As a conclusion, the Cu2O Plating Process is easy to implement, technologically advanced, and above all, reliable and economic. In that way, our innovative plating technology : • comes up to current specifications and even exceeds the market expectations, • answer potentially to the evolution in specifications, • is adaptable to most industrial processes. For more information, please contact : V. LORENTZ Marketing Department Tel : + 33 (0)3 89 20 47 44 Fax : + 33 (0)3 89 20 47 38 www.kermel.com Rhodia Kermel