Introducing solder-based electronics, with solder functioning as resistor, capacitor, and power source

This paper introduces solder-based electronics, wherein solder functions as low-resistance (mΩ) resistor, low-capacitance (pF, permittivity-based) capacitor, and low-voltage (μV, electret-based) power source, as shown for unpoled tin-based solders. The functions are controlled through the dimensions. For a given cross-sectional area A, increasing length l enhances voltage V′ while diminishing the capacitance C (with capacitors in series). For a given l, increasing A enhances C while diminishing the resistance. An electret is a permanent electric dipole having DC voltage V′. Increasing A decreases the V′ fluctuation. The V′ (hence the power ζ and volumetric power density P′ also) increases linearly with l (due to Ohm′s Law) and A (for A ≤ 30 mm², due to the number of electron–atom interaction sites and hence the electret charge increasing linearly with A); increasing l or A by a factor of N approximately increases V′ by the same factor. Increasing A (not l) causes the electret′s electric field to increase significantly. Steel is used for studying the effect of A. The Sn-4Ag solder is superior to the steel in V′ per unit volume (volume = lA) and in P′. The ζ is increased by increasing A much more than V′ or P′ is. By increasing A by a factor of 20, ζ is increased by a factor of 473, P′ is increased by a factor of 23.4, and V′ is increased by a factor of 3.85. Negative deviation from linearity occurs at A > 30 mm², with ζ being approximately linearly related to A.