For a first design (e. There are many calculators available online, as well as built into your PCB design software. . 63mils via height. The characteristic impedance of the trace can be calculated using the below formula: Formula to calculate characteristic impedance of a PCB trace. Vias (plated holes) are used to route electrical signals among different layers of a multilayer. Where: Z0 Z 0 = characteristic impedance of the asymmetric stripline in ohms (Ω). You can’t rely on these online calculators. FYI, I followed 2nd option and values were quite similar. The characteristic impedance of your microstrips is determined by the trace width for a given layer stackup. For example, if you wish to input "25000000", just type "25M" instead. If you need to use differential pairs, you. *As Trace Width Increases, Trace Impedance Decreases (Thickness has Min Effect). Figure- Allegro automatically assigns trace width 12. Microstrip Impedance Calculator. 6mm 2. Using the EEWeb Microscrip Impedance Calculator, I find that with 1oz/ft^2 copper and a substrate height of 0. Qorvo Calculators and Design Tools MatchCalc Qorvo MatchCalc is a free downloadable RF/microwave matching calculator with ideal tunable passive components. The surface finish is neglected. Other parameters to consider. T is the trace thickness [oz/ft 2], W is the trace width [mils], R is the resistance [Ω], ρ is the resistivity parameter, whose value for copper is 1. Track width, in this specific case where impedance control is not needed, must guarantee a smaller enough resistance to the trace. You can use our trace width calculator to design the right traces for your boards. β2 = 0. Click on Setup -> Constraints > Electrical Constraints Set - > Differential Pair Value - > Calculator > If you put 10 in the Line Width, the calculator calculates the single ended as well as differential impedance. Use a 4-layer board so you can achieve h ~= 0. Once the required impedance and trace geometry are determined, the next step is to calculate the trace width. The edge couple differential microstrip transmission line is a common technique for routing differential traces. Sierra Circuits’ Trace Width calculator Sierra 3-in-1 trace current calculatorThe stripline impedance calculator provided below is useful for gaining an initial estimate of trace impedance for striplines. AS9100D – Military & Aerospace. Before the length-tuning section, the odd. Select a Configuration. This calculator helps translating the color bars from the resistor to its value. Layers contain controlled impedance that is why we need to specify these impedances in the fab notes since there can be more than one value of impedance traces per layer. (It is calculated by combining the line thickness, the dielectric constant of the board, and the distance between the line and the ground plane. This time I am trying something new. This is assuming that you have a Design Rule in place which links the impedance profile to a. Microstrip Impedance Calculator. εr:Controlled impedance traces can minimize signal reflections and thereby reduce propagation delay. Yes, copper poor around your differential stripline will substantially affect the characteristic impedance. And that is how you can easily calculate the impedance and trace. It seems I could largely do without any impedance matching considerations, given what the trace lengths are. Abrupt changes in trace width cause impedance discontinuities. Provide values for H, T, W and the relative permittivity of the dielectric and click the button corresponding to unknown parameter Z o to calculate its value. The Smith Chart achieves this by superimposing a grid on S11 that maps load impedance. Hi there, and welcome to the Tools portion of EEWeb. Adequate trace width is necessary to ensure the desired amount of current can be transported without overheating and damaging your board. I celebrated my 18th birthday playing with an oscilloscope — a gift from my grandparents. The formula used in this calculator is an approximation for the characteristic impedance of a coplanar waveguide: scssCopy code. ViaMin. To use it, you simply need to input your circuit's impedance and the voltage you. 5 mil which we can round to 14 mil. β1 = 0. TLDR: 1. Calculate trace width values based using the IPC-2221 charts by providing inputs such as current thickness and temperature values. Impedance Matching Calculator Inductance Conversion Op amp voltage & gain Passive Filter Calculator PCB trace width Pull up Pull down resistors Transformer Turns Calculator Twisted pair impedance Manufacturer Tools; Reference DesignsI will not be held responsible for any mishap or loss, either direct or consequential, that may occur as a result of relying on the figures herein. Just as a sanity check, we can quickly calculate the total inductance of a trace. These calculators will return an impedance value for pairs of trace width, substrate thickness, and copper weight values. Microstrip Impedance Calculator. Effective Antenna Aperture Calculator. Currently, thermal calculators for computing the trace width are based on IPC-2152 and IPC-2221. 30967mm) is slightly larger the size of the smallest pad (0. 3W spacing between critical traces 3. The trace width can then be adjusted. . Also, the copper thickness affects the minimum trace. They just consider the loss tangent but not every calculator considers it. Measuring the trace width we get a width of 5mm. 6mm pcb thickness ) with 8 mil trace width, 8 mil trace spacing , 1. 66, the trace height is 1. Since impedance traces are not specified here, the manufacturing focus is completely upon building a board within +/-10% tolerance of the specified dielectric thickness from layer to layer. 8 * W + T)]) ohms. 0mmCurrent layer:4-layer. The Layer Stack Manager in Altium Designer can be used to easily arrange signal and plane layers in a PCB stackup and determine the impedance of traces in each layer. Modeling approximation can be used to understand the impedance of. The surface finish is neglected. Some of the primary design requirements of high-voltage boards are defined in IPC-2221B. Simons, "Coplanar Waveguide Circuits, Components, and Systems", Wiley. o use this calculator, enter the parameters of the regulator . This form of microstrip is composed of two traces. A PCB. 1. 2 Stripline Impedance A circuit trace routed on an inside layer of the PCB with two low-voltage refere nce planes (such as, power and / or GND) constitutes a stripline layout. This flow is outlined below. The surface finish is neglected. There are two ways to calculate the impedance of each layer in a stackup. Select the trace under properties. Using the EEWeb Microscrip Impedance Calculator, I find that with 1oz/ft^2 copper and a substrate height of 0. With this data, you can easily calculate the trace impedance of any PCB using an impedance calculator. trace width and thickness, distance from other copper features, dielectric constant, and dielectric thickness or distance to reference plane of the board material all contribute to the impedance of a. Through PCB impedance control, the impedance offered by the trace to an alternating current signal can be predetermined. ( 0. Microstrip Trace: Embedded Microstrip Trace: Stripline Trace: Dual Stripline Trace: Geometric Parameter Definitions. 35 ohms. spacing: 0,15mm. Now with the values shown above for the characteristic impedance and the trace width/spacing pairs, we can determine the spacing that causes the trace width for a 50 Ohm odd-mode impedance to also produce a 50 Ohm. Layout designers will use a PCB impedance calculator to solve the electromagnetic field and deliver accurate trace variables for fabrication. Where W is the trace width, L is the trace length, and H is the trace thickness. This is found to be 10mm. The edge couple differential microstrip transmission line is a common technique for routing differential traces. High-speed PCBs operate in the range of. Use the results from #3 to calculate the width profile with. T-Match Topology. 72mil. Thickness: Thickness of the stripline conductor. Trace width is one of the most influential elements affecting characteristic impedance and Figure 4 below demonstrates the relationship between characteristic impedance and trace width. If impedance control is necessary, determine the trace width required to reach your impedance target. This Javascript web calculator calculates the trace width for printed circuit board conductors for a given current using formulas from IPC-2221 (formerly IPC-D-275). 6 Band Resistor. For my results, I find that the minimum inductance is 292 nH per meter when ( w/h) = 1. We will also tell you by how much you can. Sierra Circuits’ PCB Conductor Spacing and Voltage Calculator calculates the minimum spacing between two conductors if the potential difference between them is provided. Trace Impedance Calculator; Length Conversion; Wire Size Conversion Calculator; Inductance Conversion; See. For example, when a trace bends at an angle of 90 degrees, trace width changes significantly. There are several parameters to consider when determining impedance, including: Trace width A differential stripline pair refers to two traces located between two reference plane layers, which are routed as a differential pair. The thickness of acrylic adhesive through the rigid portion of the panel shall not exceed 10% of the overall construction. PCB Trace Width Calculator & PCB Trace Resistance Calculator per IPC-2152. as input parameters i looked up the material datasheet from my board house and got: Er 4. 3mm, as shown below: This increases the impedance slightly to 91. Dielectric Thickness (h) Dielectric Constant (εr) Calculate. W: trace width: T: trace thickness: H (/H1)You can use our calculator to determine various trace components, such as trace temperature, maximum current, resistance, voltage drop and power dissipation. Discontinuities cause signal reflections due to impedance mismatch compromising signal integrity. ] Internal Layer Results: Copper Area: External Layer Results: [Mils] [Square Mils] [Volts] Trace Width Calculator Results: Via Current. Designing trace width for HDI impedance adjustments. 76mm Rogers4350B substrate at a certain frequency and with 35 micron. H: Height (thickness) of the dielectric substrate. A differential stripline pair refers to two traces located between two reference plane layers, which are routed as a differential pair. Therefore, the IPC-2141 equations are only accurate when attempting to calculate a trace width corresponding to a 50 Ohm single-ended. An embedded microstrip can be constructed using a microstrip with a solder mask. 25 mils, Impedance = 50 Ohm. Calculate Minimum Trace Width. 44. 3 mils in the Substrate 1 Height text box, re-enter 75Ohms in the Impedance text box and click the Upper Trace Width Calculate button W2, the upper trace width resolves to 5. 50 Ohms and then specifically sets this trace width as a qualifier. Does trace length affect impedance? Yes, trace length can affect impedance,. Pasternack PCB Microstrip Calculator is an online calculation tool that lets you compute a microstrip's height/width ratio, impedance and relative dielectric constant for a microstrip transmission line. For example on 0. The manufacturer provides a stack up as well as a 2D calculator for determining trace width: here The manufacture's calculator computes 3. Dual Stripline Trace. 3mm. β1 = 0. Loop Inductance Calculator. Calculate the impedance of a twisted-pair cable given dimensions and find the signal propagation delay, capacitance, and inductance per unit. Keep in mind that the reactance of the ideal inductor has the same magnitude as its impedance. 1kOhm, 1% tolerance: Brown Black Black Brown Brown. my board thickness is 1,5mm (base material) and 35um Cu. The standard trace spacing for PCB design can vary based on the application, but common values range from 6 to 10 mils (thousandths of an inch) for general-purpose designs. If you reduce this trace width to 19 mils, the characteristic impedance will result in about 52. How to calculate PCB Impedance? First, determine the dielectric constant. 25 mm (about 10 mils) might achieve a 100-ohm characteristic impedance. If the ratio is about 0. Features: Three-in-one calculator. The fabrication etching process will have a greater effect on traces that are long and isolated, so it is better to make them wider when possible. The width of the conducting layer is important to calculate the radiation intensity since it directly affects the bandwidth of the signal waves. H1=> 8. The tool achieves this by applying particular formulas for each component, conforming to industry standards such as the IPC-2221 standard for circuit board design. There are four different types of impedance used in characterizing differential trace impedances. 062. Trace inductance increases with trace length and lack of ground plane. To calculate PCB trace resistance, The 50 ohm PCB trace calculator is designed considering the following formula. In my layer stack manager, I have the following: Note that Altium calculates that the trace. 25mm between the differential pair with a width of 0. While this calculator will provide a baseline, any final design considerations should be made towards loss, dispersion. From the above tables, we can evaluate the current carrying capability of a specific trace width. Electromagnetic fields are part of the spectrum ranging from static magnetic fields to high-intensity gamma rays. Just enter the given values for trace thickness, substrate heights, trace width, and substrate dielectric in the. Overview. and anded up with: so width: 0,47mm. To use this tool, enter the values for trace thickness, substrate height, trace width. Coil Inductance Calculator. 44, c = 0. Microstrip Width Calculator. 68. com Blog » PCB Trace Width Calculator - March 21, 2006 […] PCB Trace Width Calculator January 31, 2006 This Javascript web calculator calculates the trace width for printed circuit boards based on a curve fit to IPC-D-275. PCB Trace Impedance Calculator. H 2 H 2 = subtrate height 2. With PCBWay impedance calculator, you can calculate the approximate impedance of your PCB / high frequency circuit board. A 20 mil trace will have a much greater tolerance for losing metal than a 3 mil trace would. The impedance calculations will take into account their thickness and dielectric constant. The trace width required to deliver a specific impedance can be calculated as part of an impedance profile, in the Impedance tab of the Layer Stack. You can use our trace width calculator to design the right traces for your boards. 2. When dealing with transmission lines, Characteristic impedance is a crucial parameter, probably the most crucial that you will encounter. 5mm, T=0. Other conductor properties include: ; Conductor skin depth ; Conductor voltage drop ; Conductor. 5mm pitch BGA. Via pad diameter (in mils) Trace/space width (in mils): This is the width of the trace and the space between them. H 2 H 2 = subtrate height 2. Any variation or discontinuities to the impedance causes signal reflection and distortion. Impedance; Signal Loss; S Parameter. Balun's Single Ended Impedance = 50 Ω Ω. 3 is a plot of impedance versus trace width for the three most common types of transmission lines in PCBs-- surface microstrip (SMS), buried microstrip (BMS) and centered stripline (CSL). The characteristic impedance (Z o) of coplanar waveguide with ground or microstrip lines with signal side ground plane can be calculated using the active calculator or the equations at the bottom of the page. 0mm Outer Copper Weight. 8W + T)] Where: Z: Characteristic impedance of the microstrip trace. Polar or rectangular grids only allow direct reading of S11. 1kOhm, 1% tolerance: Brown Black Black Brown Brown. Trace impedance is dependent on not only. This should be provided along with the PCB material. I would like to increase the width of my traces whilst maintaining the same ~50 Ohm nominal characteristic impedance of my line. The calculator by Spok consulting, for example, gave the following result: Problem. 8W + T)] Where: Z: Characteristic impedance of the microstrip trace. 5mm). These calculators will return an impedance value for pairs of trace width, substrate thickness, and copper weight values. Tool calculations are based on the IPC-2152. Group components of specific applications together to reduce the loop areas. L-Match Topology. 25 Dimensional units: mm milsA uniform transmission line on a PCB has a definite trace width and height, and is at a uniform distance from the return path conductor - which is usually a plane at a certain distance from the. To find out the width of the microstrip, enter the target impedance (Zo), trace thickness (t), dielectric thickness (h), and relative dielectric constant (εr). The board thicknesses are given in mm so it is not clear that the required units for trace width appear to be mil (0. You will see the trace width is 5. It displays the impedance of the input and output match in a 50Ω test environment as measured on a network analyzer. 949. To use this tool, enter the trace width, thickness, ambient temperature, temperature rise, and the microstrip length and click the "calculate" button. R. Use an impedance calculator to determine the trace width (W) and spacing (S) required for the specific board stack-up being used. This dialog allows you to view and (if required) modifythe formulae used to calculate Impedance and Trace Width when using impedance-controlled routing. Target Impedance (Z0) Trace Thickness (t) mils. Contents. 29 mm width traces to obtain 100 Ohms ZDiff while using 0. Modeling approximation can be used to understand the impedance of. This is more than the to times trace width which is recommended (also read as close as possibly). For a 1 inch trace, this value would have a total inductance of ~7. They are very simple to read, and the values in. T is the thickness of the trace. After determining the layer thickness and copper weight, you simply determine the trace width you need to use for a defined characteristic impedance. To use these to design for a target impedance, simply cycle through various geometric. when i use Saturn PCB design to match the differential impedance to 100ohms i get 0. R. 7563 mm (~30 mils). Frequency: Frequency at which the stripline is analyzed or synthesized. So Adjust trace width to match the impedance to 50 Ω Ω. For low power signal traces it is generally advised to keep traces small to increase the available space available for routing. 063" thick PCB, that means a trace width around 120 mil. Where: H is the height of the PCB above the ground plane. 4mm PCB for a trace width of 0. This calculator assumes the distance between the two reference planes to be an equal distance. The default units for all given values, except the subtrate. This design tool is based on the charts in IPC-2221. 020 inches) for typical PCBs. Microstrip Trace Impedance Calculator The calculator utilizes the formula for calculating the impedance of a microstrip trace: Impedance (Z) = [87 / √(ε + 1. In this demonstration, we’ll choose uncoated microstrip single-ended impedance calculator. Using a calculator with an existing stackup involves a simple process to converge on a useful trace width for a target impedance. 4. Pressure Conversion. The second part shows the impedance table which gives the details of impedances on different layers along with the trace widths and trace spacing. 1. A transmission line should have a uniform characteristic impedance. The tool provides two networks that will have the desired impedence at that frequency. The dialog is accessed from the PCB Editor by clicking the Impedance Calculation button in the Layer Stack Manager dialog. PI Network Impedance Matching. The edge couple differential symmetric stripline transmission line is a common technique for routing differential traces. Summary. Microstrip Differential Impedance Formula. Step 4. 4 mil, εr. 2. The wider a trace is, the easier it is to fabricate. 6. Calculates the optimum trace width for a given impedance value; Determines total insertion, dielectric, and conductor losses; 2. Impedance vs. 035 mm, we have a PCB trace width of w = 0. The Calculator. 44. 2mil is the calculation trace width(the adjusted trace width,need to adjust trace width to meet impedance)Access Rogers' calculators, literature, technical papers and request samples on your smart phone or tablet through the ROG mobile app. At the point of bending, the trace width is 1. Just as important as determining an appropriate trace width for a single-ended trace is determination of an appropriate spacing between two traces in a differential pair. Figure 2. (dielectric constant Dk=4. For differential pairs, a coupled microstrip line can work also. 3-in-1 calculator: temperature rise above ambient, trace width, and maximum trace current capacity; Evaluates trace resistance, voltage drop, and power loss; PCB dielectric requirement. 6mm spacing with a trace width of 0. 25 Ohms and is therefore out of the limit. Select a trace impedance profile over the length of the taper. Asymmetric Stripline. To get a 50 Ohm characteristic impedance, you just have to define your trace width in the proper proportion to the H of your. 3 shall be used. Adjust the length matching to achieve propagation delay. PCB Trace Width Calculator This tool uses formulas from IPC-2221 to calculate the width of a copper printed circuit board conductor or "trace" required to carry a given current while keeping the resulting increase in trace temperature below a specified limit. PCB trace impedance can range from 25 to 125 ohms. Provide values for H, T, W and the relative permittivity of the dielectric and click the button corresponding to unknown parameter Z o to calculate its value. PCB Trace Width Calculator & PCB Trace Resistance Calculator per IPC-2152 . of typical printed circuit board trace geometries. The Smith Chart graphically maps S11=reflection coefficient= (ZL-Z0)/ (ZL+Z0) to Load Impedance (ZL), normalized to Z0 (source impedance = center of chart). The impedance depends on the net width, the net height, the board type and so one. Impedance Calculator; Via Impedance Calculator; Trace Width and Current Capacity Calculator; Via Current Capacity Calculator; Signal & Plane Layer Estimator; Conductor. 17mm in order to achieve this 45 ohms. Calculate the Differential Microstrip Impedance of a transmission line based on the the distance between the strips, height of the substrate, trace thickness and dielectric constant of the substrate. At 10 MHz, you don't need to worry about trace width/impedance unless you're using long traces and very fast rise/fall times. ) such real numbers for the line impedances are sufficient. This calculator computes the trace width of a stripline if the maximum current, trace thickness, temperature rise, ambient temperature and length are given. We get a lot of questions about trace impedance and how to calculate the right trace size to hit a specific impedance in a manufacturable PCB. Microstrip Trace Impedance vs. Should I just go with SaturnPCB's values and pray it works? The difference seems pretty severe (10%) but I guess would fall within the 25% tolerance, so. Optimization results for example 2. Dielectric thickness vs. Calculate the impedance gradient and the reflection coefficient gradient. I would like to calculate the trace width of a dipole PCB antenna in order to match a 50ohm impedance. Single Ended Impedance Ω. Understanding transmission lines and controlled impedance. /sq. As an example with 1 A. It mentions formula or equations used in this Microstrip Width Calculator. It gave me a trace width of 6. Most designers take the controlled impedance approach and devise a target for their trace width/spacing for single-ended and differential channels. IPC-2152 Calculator. ΔW = (W-W1) ( mils ). This procedure produces the result ( w/h) = 1. to select appropriate isolation materials, layer thickness, trace width, distance between traces,. If the calculated routing trace width is a value that cannot be ordered, you can tune the width and gap settings. Use the max current (Imax) and max current density (J) to determine minimum trace width: Trace Width (mils) = Imax (A) / J (mA/mil2) Add margin of 20% for reliability. This calculator is designed to calculate the characteristic impedance of a broadside couple stripline (see diagram below). W W = trace width. $$H$$ = subtrate height $$W$$ = trace width $$T$$ = trace thickness $$epsilon_{r}$$ = substrate. The dielectric constant of a material IS slightly frequency dependent. 5 mm; substrate dielectric: 4. The application below provides a simple way to calculate the required trace width (in mil) for a given input current and temperature. We recommend the software from Polar Instruments if you want to get exact impedance calculation. JLCPCB Impedance Calculator. 0. Differential Impedance of. Sierra Circuits’ Trace Width, Current Capacity and Temperature Rise Calculator is an advanced PCB tool that works based on the latest IPC-2152 standard. In addition to the width and thickness of the trace, the impedance is a function of the thickness of the substrate, the dielectric constant of the substrate, and the distance of the trace from the ground plane. Enter the same substrate parameters and 14 mil for W. 2. There are four different types of impedance used in characterizing differential trace impedances. trace width:. A pair of lines can be modeled as follows: Differential pair line. It is possible to select other units. For example, if you wish to input "25000000. Impedance lines should not be patched, and any gap in the signal trace should not exceed 10%. It shows the minimum trace-to-ground spacing required to. PCB Trace Width Calculator. Share. What is the width of a trace for 100 ohm impedance? The width of a trace for a specific impedance depends on the dielectric constant, height above the reference plane, and other parameters. The Microstrip Impedance Calculator is a vital tool in the design and analysis of microwave circuits. Gaps in signal traces impact the entire test waveform, and its single-point impedance is too high, making the entire waveform uneven. Now with the values shown above for the characteristic impedance and the trace width/spacing pairs, we can determine the spacing that causes the trace width for a 50 Ohm odd-mode impedance to also produce a 50 Ohm characteristic. To configure the board layers and input the material widths, go to the “Design” pulldown menu and click on “Layer Stack Manager”. It’s a three-in-one calculator. Tuning the Width and Gap Settings. Ohm’s Law provides the framework for solving network analysis problems; when the curtain gets pulled back, Ohm’s Law updates to become the relationship between voltage, current, and impedance, not resistance. Calculations are based on formulae from IPC-2221. The manufacturer can then choose to make a test cupon on the frame outside the actual board and use this width for impedance control. At 2 amps I'd worry more about voltage drops. 414 times higher than the actual trace width. This dialog allows you to view and (if required) modifythe formulae used to calculate Impedance and Trace Width when using impedance-controlled routing. Using typical values of W= 9 mil, H= 24 mil, T = 1. I had a request for a calculator to find the width of a PCB trace based on its voltage drop or power dissipation. where. It’s a three-in-one. You can find trace impedance calculators online or in your CAD software. The IPC-2141 trace Impedance calculator will help make initial design easier by allowing the user to input basic parameters and get a calculated impedance according to the IPC-2141 standard. There are some advantages to using a microstrip transmission line over other alternatives. The impedance Z 0 of a transmission line consisting of a circular signal conductor having a diameter d and centered between parallel ground planes separated by a distance h is given by: Eq. To use these to design for a target impedance, simply cycle through various geometric values for the trace width until the calculator returns the target impedance. Best is 5mils, but 4mils is OK, too. The differential impedance of MIPI tracks should be 100 Ohms, not 90 (USB requires 90). For a first design (e. 1. 208mm per stackup at here. For more accurate numbers, you can use a trace impedance calculator online. 45 for gold. 378t} W = 1. where Z 0,surf can be computed as specified in Eq. 5 mil (0. For example, on the left side of Figure 4, a 4-4-4 mil geometry has a differential impedance of 91 Ohms. Note: The results are only for approximation and rough estimation, the final values and the. In the attachment you can see that in the Stack up Editor, I can calculate trace width for single ended trace that gives 50 ohm impedance for a given stack up settings. The PCB internal/external trace resistance shall be calculated according to the following formula: R = (ρ * L / (T * W)) * (1 + α * (TAMB – 25 °C)) Where: R is the trace resistance [Ω] ρ is the resistivity parameter, whose value for copper is 1. IPC 2141 Trace Impedance Calculator. Then, using a standard PCB trace impedance calculator or using the formulas in a textbook, you’ll find that the required trace width is 13 mils. The first thing to remember is that signal reflection in PCB transmission lines occurs due to impedance discontinuity. Trace Width (W) Figure 3. Use our online tool to calculate the minimum trace width for a given current and copper weight. Modeling approximation can be used to understand the impedance of. The trace width formulas are: I = 0. Differential Impedance of Microstrip. o use this calculator, enter the parameters of the regulator . The edge couple differential microstrip transmission line is a common technique for routing differential traces. W: trace width: T: trace thickness: H (/H1)The trace width calculator uses empirical formulas based on long traces with no special heat sinking. One of the most common inquiries that we encounter at Bittele electronics are regarding our standard trace widths for a given board thicknesses and copper weight. Reference: R. Trace width is an important design parameter in PCB design. 4 mm, trace spacing S = 0. Trace Width (W) ( mils ) Calculate W . 254mm. Since my layer thickness is 0. To use it, first select the tolerance of the resistor: 10%, 5% or equal or smaller than 2%.