| 11. | The second is due to an isotropic etchant, which means the etchant etches in all directions equally.
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| 12. | The etchant would bite into the unprotected areas, causing the painted areas to be raised into relief.
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| 13. | In bubble etching, air is passed through the etchant bath to agitate the solution and speed up etching.
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| 14. | In spray etching, the etchant solution is distributed over the boards by nozzles, and recirculated by pumps.
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| 15. | A test piece may be made with etching times noted, as the strength of the etchant will vary.
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| 16. | The wafer can be immersed in a bath of etchant, which must be agitated to achieve good process control.
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| 17. | In these publications, by comparison, the Wright etch was the preferred etchant to reveal defects in silicon crystals.
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| 18. | On high reliability boards a process called etch-back is performed chemically with a potassium permanganate based etchant or plasma.
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| 19. | Small-scale etching requires attention to disposal of used etchant, which is corrosive and toxic due to its metal content.
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| 20. | A new grade of ceric ammonium nitrate was introduced with tighter metals tolerances for use as an electronics-grade etchant component.
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