Impedance Calcuator PCB stackup, signal integrity and controlled impedance: Signal integrity tools: Stackup design. Time Domain Reflectometer (TDR) impedance measurements are essential for ensuring signal integrity in your design. Controlled differential impedance starts with characteristic impedance. , FR4), and layer stackup. 3. The characteristic impedance of your microstrips is determined by the trace width for a given layer stackup. 5 pF/sq. You can reduce this effect by implementing coaxial via structure. The Sierra Circuits High-Speed Design Guide helps you design PCBs with signal frequencies from 50MHz to as high as 3GHz and beyond. The impedance of a trace is calculated based on the placement of plane and signal layers in the PCB stackup. The two impedance controlled lines I have are for USB (90 ohms differential), and a 2. Many will also be able to include an impedance test coupon on each panel that they fabricate - this can be used to measure the real impedances achieved on. The build-up provides the following information: The copper thickness and weight. Leave enough space between traces and ask the manufacturer for controlled. Start Designing. PCB Stack-Up Altium Designer’s impedance calculator takes your board layer stackup information and sends the trace width and thickness results to your design rules. The PCB stackup you create for a high speed circuit board will determine the impedance, as well as ease of routing. Stack-ups, also known as build-ups, carry the details of trace width for different controlled impedance traces such as 50 ohms or 100 ohms differential. PCBCart provides multilayer circuit boards with layers in the range from 4 to 32 layers, board thickness from 0. 2 is an example of the amount of. Flex thickness x 6. To elaborate, the number of layers on top of the core should be equal to the layers on the bottom. The stack-up operator places the copper foil (layer 4 in the above image) and prepreg sheets on a heavy steel base plate. 8-layer PCB stackup question. Most CAD systems provide an impedance. Impedance: For successful impedance-controlled routing, the circuit board needs to be set up with the correct board layer stackup, trace widths, and spacings. An example structure that extends the via structure impedance beyond 5 GHz is shown below: Example via antiap and stitching via arrangement around a signal via with a teardrop on an 8-layer stackup. PCB. This should also show which layers are rigid material and which layers are flexible material including copper weights. Stackups must be kept symmetrical, so there must also be 4 mils of dielectric between layers 7 – 8. Learn more about the industry’s best field solver built into your PCB stackup calculator. Altium Designer. Panel size. Controlled impedance. Procedure to use the calculator: 1. 7 mil (0. Using the built-in Simbeor ® impedance calculator, the PCB editor's Layer Stack Manager calculates the trace width needed to deliver the specified impedance. PCBCart's Standard PCB Layer Stack-up. Main features of this Stackup Designer tool: The stripline impedance calculator provided below is useful for gaining an initial estimate of trace impedance for striplines. 5oz to 6oz), inner layer copper thickness from 18μm to 70μm (0. Additionally, minimizing the routing from the pad to the via can save space. Below is the stack up of my PCB and as seen "L3_MID2_H" Top Ref is "Layer 1_MID2(GND)" "Layer 1_MID2(GND)" is is shown below which appears to be OK. Unit: Options are mm, mil, μm, and inch. Arranging stack-up in KiCad. Flex thickness x 24. 033 inches. 0521164. 1. Track width (w) = 137 micron. It has been correlated many times. In other special cases or Advanced PCBs (you need to choose " Additional Options" and custom stackup or control impedance): 1. A fully unified, heavily rules-driven PCB design platform for impedance controlled routing in high-speed PCB design. Automated tracking of glass-reinforcement pitch — for mitigating glass-weave skew (aka: fiber-weave effect). 4+6+4 HDI stackup Layer buildup/stackup reference. 4 mil (1 oz finished thickness), respectively. Metal core PCB stack-up. 9 is an example of the amount of information that must be included in the. Ensure that the wire thickness is the same as the trace width. Before starting the layout design, it is necessary to have a stackup design and to set up the layout. High-quality circuit boards as prototype and series at reasonable prices. If the ratio is about 0. 24 hours a day, 7 days a week. 6mm) That should give the traces around 90 Ohms differential impedance according to the PDF, but when I try to input it to my impedance calculator (Saturn PCB toolkit V7. We will show you how our Stackup Designer, Impedance Calculator, and Material Selector work. Standard PCIe boards incorporate a 4-layer stack-up with two interior power planes and two signal layers on each surface. PCB Impedance-Calculation: Help with the dimensioning of the impedances of your circuit board. Repeat #1 and #2 for each layer. For those who are new to multilayer PCB stackup planning, standard 2 to 16 layer stackups have been provided that are commonly used. The layer stackup also affects cross-talk and net impedance; and these two factors, in turn, drive the functional performance of a PCB. Use the Impedance tab to start your PCB impedance calculation for different layers. Similar to the Saturn tool, this capability allows you to experiment with the stackup and track dimensions to estimate impedances. And that they have the same separation from each other along the entire length of the line. The PCB : 4 layers, 1mm thick, designed for JLCPCB's impedance controlled stackup JLC7828. Altium Designer includes a PCB trace impedance calculator, PCB trace width calculator under IPC 2152, and a plethora of other important design tools. Note: The results are only for approximation and rough estimation, the final values and the. Sierra Circuits’ Via Impedance Calculator uses the physical dimensions of a via to calculate its capacitance, inductance, and impedance. 4-Layer Impedance Control Stackup. At its worse, this combination has the potential to affect the signal and power integrity of the circuit. Assuming the differential pair I am routing is requiring 90 ohm (this is what the hardware guideline say "Route the USB differential pair on the top layer with a trace width and differential spacing tuned to the PCB stack-up for 90Ω differential impedance "). 2 of the Microstrip Calculator, h=H1 and b=H2-H1. Calculating rise time and propagation delay is important to carry out the impedance measurements. Contents. It is a full-featured Excel-based tool that helps plan the PCB stack-up so that controlled impedance traces can be effectively implemented. Calculating PCB Stackup. 2 and a Df of 0. The stack-up designates the materials to be used for the manufacture of a multilayer circuit board. For more demanding applications, special high-frequency PCB materials (for example: Rogers RO4000 [2]). 035mm Prepreg 7628*1 0. Controlled impedance is the characteristic impedance of a transmission line formed by PCB traces and its associated reference planes. As a rule of thumb, a four layer board will produce 15 dB less radiation than a Double side PCB board. Microstrip Impedance Calculator. In both cases, you’ll need to enter your stackup information into the calculator to get accurate results. Impedance Calculator; Via Impedance Calculator;. It is always a compromise between trace impedance, trace width and prepreg/core thickness and it is best to use a stackup calculator to provide quick ‘what if’ analysis of the possibilities. It is tough to find and fix every single fault in a circuit board. You will then be presented with a table representing the suggested stack-up for that type of substrate. = 1. g. Dielectric material (partially cured) is used to bond copper cores and copper foil in the layer stack-up. It is possible to minimize the dependency on discrete decoupling/bypass capacitors by taking advantage of the inherent capacitance in a stack up. It enables engineers and designers to understand and control the intricate aspects of PCB layout. Route your single-ended and differential pair traces. Gerber files are the output of circuit board design process. 5 oz) and 1. Impedance mismatches can lead to signal reflection, ringing, noise, and loss of signal integrity. The relationship between these tools usually goes further than that though with this data also being made available to other portions of the system to configure design rules. ) to measure the impedance, and both gave roughly 40 ohms. 5(double-sided PCB) 7628 Prepreg 4. 25. Route signals to ensure the return path is directly underneath the signal trace. 8 core of FR4 material, we would have a propagation delay of approximately 150 ps/inch, or approximately 6 inches/ns. 3D PCB editor Easy to use Printed Circuit Board Editor. PCB stackup import/export utilities — for popular signal integrity software, enabling design reuse and more accurate simulation results. Maintain symmetry in your build-up. I am planning to have the PCB (4 layer) manufactured at JLPCB controlled impedance service. 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. Stripline routing has a big advantage in being sandwiched between two ground planes. Layer 3 - Signal/Power. A typical value of 1/7 Lambda has been set by default. It is a full-featured Excel-based tool that helps plan the PCB stack-up so that controlled impedance traces can be effectively implemented. The next important part of the electronic circuit design process is to draw the schematic diagram using EDA tools like Altium, KiCAD, and Cadence Allegro. It defines the acceptable variation between the maximum and minimum limits. Warning Are you sure to logout ? First Name [ Required ]:. Converting a two-layer board to a four-layer board increases the overall. The tool implements numerical solutions of. 3. TDR feeds a pulse onto the transmission line on a test coupon. It works in parallel with the standard. DFM for flex and rigid-flex PCBs with SMT involves selecting application-specific circuit construction types, laminates, coating thickness, trace routing strategies, bending, and EMI capabilities. The grid of layers is divided into 2 regions, the layers in the stackup are displayed on the left, then for each signal layer in the stackup there is a layer displayed in the. The target impedance value of a design is given by the equation: = ( V x ripple%) / ( 50% x Imax) The formula represents a combination of voltage fluctuation and transient current. The Simbeor SFS. 059”. There are in general two approaches to create a PCB stackup, known as controlled stackup and controlled impedance. For class 3: Minimum of 8 mils diameter. 02. To validate the trace width and spacing in your design, use the Better DFM tool. Connections are formed in the copper layer (s) as conductive traces by etching away (removing) unwanted copper. ] JLCPCB StackupsTechnically, there is no proper limit to N, though it depends on the layer count and the outer layer thickness. You will then be presented with a table representing the suggested stack-up for that type of substrate. Here, the via carrying the signal is placed at the center and is surrounded by 4 ground vias. @ahbushnell The main calculation I used is the one from Saturn PCB Toolkit, and the result is largely similar in "coplanar wave" with the gap used, or "miscrostrip" configuration. 2116 Prepreg 4. Advice for 90 Ohm traces of a USB 2. Using an impedance control PCB calculator, the engineer determines that 50-ohm single-ended traces require a width of 6 mils and a spacing of 10 mils. 4mm to 3. Using the built-in Simbeor ® impedance calculator, the PCB editor's Layer Stack Manager calculates the trace width needed to deliver the specified impedance. Explanations of signal integrity issues. 6mm thick) This has been updated October of 2020. Currently, the maximum width is set to 10 mil, but I normally set this to 5% higher than. The 1+N+1 stack-up is the simplest one without microvias. Flex PCB controlled impedance stack-up with stripline Surface microstrip for differential signaling in flexThe characteristic impedance of a PCB trace should remain constant to have a uniform transmission line. The following is the usual stackup information(4,6,8 layer PCB standard stackup), which also can be used as stackup of impedances. Key cost drivers for rigid circuit boards. Deliver -/+ 5% impedance tolerance. PCB Layer Calculation and Documentation Tool User Guide Speedstack PCB Stackup Builder Polar Instruments Ltd Polar Instruments Ltd. 4mil (1 oz) for plane layers. My Total PCB thickness is around 1. 01) Speedstack PCB Layer Stackup Design Software bundles – Please note the following packaged software combinations: Speedstack PCB 2022. Once these decisions are made, a designer needs to determine the PCB trace width required to hit their required PCB transmission line impedance. The stackup drawing must contain more information than in the past and the fabrication notes will need to be expanded. He added, “Designers today understand why controlled impedance really matters. RLC Resonant Frequency and Impedance Calculator. When gold is deposited during the ENIG process, it relies on a corrosion reaction to place itself (the gold) on the nickel substrate. Below is an example of HDI stack-up generated using the Stackup Designer. Design for testing (DFT) evaluates the board’s accuracy based on functionality and manufacturability. You’ve probably also seen some calculators. A coplanar waveguide calculator will operate in one of two ways. 2 Foreword the theoretical, but also the practical elements. The most common problems seen in Gerber files include design mismatch, insufficient clearances, obsolete file formats, unregistered layers, and incomplete files. 5 mil (0. The iCD Stackup Planner features a precision 2D Boundary Element Method (BEM) Field Solver providing customers with the accuracy and simulation speed they need for high-speed PCB Design. The formula for microstrip trace impedance is: Z = 87 * (W / H) ΩThis means that the actual trace width for a 50 ohm line could vary from design to design. Contents. Ensure the positive and negative traces of the differential pairs have matched impedance. The calculator is set up to handle an asymmetric arrangement, where traces are not centrally located in the PCB layer stack. With the ever-increasing edge rates, accurate loss, and impedance calculations with actual dielectric materials, data are imperative to getting the stackup right the first time. Using a power plane as signal reference. Modify the variables to examine the effects on the trace characteristic impedance. PCB Layer Calculation and Documentation Tool User Guide . This will also affect the. Microstrip Impedance Calculator. This includes key considerations such as PCB footprint design, component placement, soldering considerations, solder mask checks, BOM assessment, testing, and panelization. 3 Common mistakes to avoid in the stack-up 2. Currently, the PCB stackup contains two metal layers (Top and Bottom) and a default dielectric layer (FR-4) between them. Cross-hatched copper plane in a flex stack-up for controlled impedance. It provides vital information like material thickness and copper weights. This will help to maintain a low impedance and short return loops. Formulas from IPC-2141A Design Guide for High-Speed Controlled Impedance Circuit Board. It also allows designer to configure drill pairs and impedance formula editor. Max. Polar Instruments (Asia Pacific) Pte Ltd . Call us: +1 (800) 763-7503 Email us:. Bandwidth Calculator & Max PCB Trace Length Calculator. Sampson Guernsey Channel Islands . 2 (double-sided) Flex thickness x 12. By leveraging mathematical precision and providing ease of use, it adds tremendous value to the field, facilitating innovative and efficient designs. Designing for a Specific Impedance [The stackup dielectric will determine what size of trace you need to use in order to conform to the particular impedance. Dielectric constant = 3. Controlled impedance routing in HDI boards requires an accurate impedance calculator in your layer stack manager. A stack-up describes the construction of a multilayer board in sequential order. If the PCB stackup is done differently, where the signal layer is closer to the power/gnd plane, then the trace can be thinner while still having the proper impedance. The JLCPCB Impedance Calculator computes track width values and recommended stack-ups from user-input values of board thickness, copper weight, layer,. That’s why they are generally preferred for flexible and rigid-flex designs. Using this application, you can quickly identify the thermal resistance of a single or a combination of vias. Damping resistors help achieve a critical damping state. Using the goal seeking facilities of the field solver to obtain the correct impedance for a structure. Process cost affects the final PCB price, and once the PCB is designed, you cannot reduce it without redesigning the board. eu. The ICD Stackup Planner calculates characteristic impedance plus edge coupled and broadside coupled differential impedance. Design and stackup in altium, For ex: 8 layers and impedance control of 100 ohms on layer 2 and 7 and ask your fabricator to suggest a stackup for same 8 layers and trace impedance of 100 ohms for layer 2 and 7 and compare the values. , DDR, HDMI, Gigabit Ethernet). 679 nH/inch. By formulas from IPC-2221, PCB Trace Width Calculator can estimate the width of copper PCB boards and the trace required under the given current, and at the same time keep the rise in trace temperature not to exceed the limit. 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. Note: The trace on the inner layer need to be much wider than the trace on the outer. Note: The results are only for approximation and rough estimation, the final values and the corresponding layer construction have to be calculated by us. Laser drilling creates precise holes on a PCB to establish connections between different layers. Sierra Circuits can assist you in designing your flex stackup. Rule #1 - Number of layers in stackup. The primary cost drivers of flex PCBs include board materials, layer count, efficient panel utilization, type of stiffeners, and surface finish. Field solvers. As an example, If I want to meet the 80Ω diff/ 40Ω single impedances, taking the first inner signal layer, and using the Saturn Edge Coupled asymmetric calculator, the input would be: H2= 180um H1= 176um w = 0. By understanding the microstrip transmission line, designers can. The first goal in stackup design is to determine the number of signal layers you'll need to support high speed routing for all your interfaces. The image above depicts a 4-layer stack-up. It does not use Er or circuit type. To help designers, multiple PCB design tools have come up with various constraint management settings. It should include impedance value, trace width, differential pair spacing, and the layer on which the controlled impedance traces are routed. Adjust the length matching to achieve propagation delay. Be warned though! The calculators only give you estimates, your board has. 3 V, you will usually be fine if you use adjacent plane layers and a few decoupling/bypass capacitors on critical components. Speedstack Si – Insertion loss & impedance PCB stackup design including Si9000e. Following images present PCBWay's default layers stack. Speedstack Si includes Si9000e. Microstrip Impedance Calculator. . 11. By integrating these DFA checks into your design. Defining 4-layer PCB stack and base material IPC4101/21, impedance calculation value. Either the desired impedance at a specific frequency is used to determine the waveguide width, or the width is entered and the impedance is calculated. PCB Trace Width Calculator. PCB Laminates & Materials Impedance calculators: Using the data created by the layer stackup generator, the impedance calculator will give you the correct width for your controlled impedance lines. The image below shows a typical 4-layer PCB stackup construction you’ll receive from most fabricators. The JLCPCB Impedance Calculator computes track width values and recommended stack-ups from user-input values of board layer,. The impedance information must be included by the layout designer in the fabrication drawing notes. You can load a preset stackup in Altium Designer using the Layer Stack Manager. (Sorry guys, I live and I have grown up in a metric world ) With these values, Saturn PCB's off-line calculator gives 57 Ohm differential impedance. Impedance matching is the way of configuring the input impedance of a load or the output impedance of its signal source. It enables engineers and designers to understand and control the intricate aspects of PCB layout. Select the number of substrate layers. g. Some fabricators can advise on track. PCB layer count estimation is a vital process in board manufacturing and cost. The stack-up should be symmetrical on either side of the metal core in a multilayer board. PCB Laminates & Materials Quick Turnaround Program; Why. 8. Below is an example of HDI stack-up generated using the Stackup Designer. 1. In The News. Note that the built-in impedance calculator does not account for the affect of vias, it assumes lossless transference from one signal layer to the next. Garenne Park St. Use 3. 1 Defining cores and prepregs 2. Type of epoxy glass to be used. So, you need to calculate how much resistance a PCB trace can provide. The Altium Stackup Manager not only allows you to define the stackup, but you can also create impedance profiles for various SE and DIFF impedances. DFT is similar to reviewing your answer copy in an examination just before the final submission. The toolset that is used to create the stackup then uses Maxwell’s equations to precisely calculate parasitic inductance and parasitic capacitance. A six-layer stackup, note that the two internal plane layers have been placed around the Cu3 (Sig) internal signal layer, as this layer and the top layer will carry the controlled impedance. In this phase, the design is entered into the schematic tool (Altium, Allegro, etc). Gerbers provide information about each and. Some fabricators can advise on track geometries if you supply them with your preferred stackup. It covers both single-ended and differential traces and is based. Speedstack PCB. Fundamentally, copper weight is a measure of copper thickness on the board. PCB Materials and Stackup Design Guidelines. g. Based on my understanding of a 4-layer stack-up, one of the best set-up I chose is 8 mil trace space and 10 mil trace thickness. By controlling the PCB impedance, unexpected damages or errors can be limited to some extent. 6 mm PCB thickness, but is this the final thickness, after lamination or before ? Also what's the margin on this thickness. Apart from the layer. Selecting and routing on prepreg vs. 4. 2 The PCB stack-up design 2. , DDR, HDMI, Gigabit Ethernet). Linked to our 2D field solver-based impedance calculator to design high-speed traces; Metal core PCB vs FR4 PCB. Garenne Park St. If a signal encounters impedance discontinuity, it will generate jitters in PCBs and hampers the signal integrity. Sierra Circuits is a minority-owned business, certified by the National Minority Supplier Development Council. Polar UK: Speedstack PCB – PCB stackup / Impedance field solver package. 2, the resulting trace width required for 50 Ohm impedance would be 15. with the following layout parameters (width|space|width): Ohm. The stackup drawing must contain more information than in the past, and the fabrication notes will need to be expanded. High speed measurement tools. If you have copper fill on other layers, you can tie them to. For example, for a simple coated microstrip with a target impedance of 75Ω it would not be unusual to specify a tolerance of ± 5%; typically, though, impedance is more often specified with a tolerance of ± 10%. Quality starts at the foundation, and IsoStack® helps you design a printed circuit board stack up with the right materials and the right combination of dielectrics to meet the required thicknesses and impedance targets– right from the very start. Whenever a designer wants a circuit board to be fabricated there are a number of ways to communicate all the requirements to the manufacturer. 4 Layer, 62mil Differential Impedance Sample Calculation (100Ω): 6 Layers, 62mil Stackup:. PCBWay manufactures multilayer circuit boards with layers in the range from 4 to 14 layers, board thickness from 0. Blind vias exist from: Layers 1 to 3; Layers 1 to 4; Layers 5 to 8 Stackup Editor Zoom: Hybrid Design Shield: Mask:. PCB layers affect electrical performance, signal integrity, and product cost. In a traditional PCB design, the designer specifies the width/clearance of the trace to satisfy the current/voltage requirements. A PCB's impedance depends on trace geometry, materials, and layer configuration. It is performed to achieve maximum power transfer and reduce the signal reflections from the load. 6- layer PCB stack-up. Just as an example, we can look at a simple PCB stackup with impedance control to see the microstrip inductance. Linked to our 2D field solver-based impedance calculator to design high-speed traces; See what Laurent Nicolet has to say about the future of PCB etching. Fortunately, the return path analysis tools in PCB layout CAD systems can easily find and report these problems to the designer. The design requires controlled impedance traces. It also has an integrated impedance calculator to get the desired impedance and trace/space values on any signal layer. What's Inside. 4+6+4 HDI stackup Layer buildup/stackup reference. Distance between tracks (s) = 254 micron. Planning Your High Speed PCB Stackup and Impedance. Stack-up and grounding. Being a board designer, you need to know the functionalities of some of the best design tools before you choose the right one. Used interchangeably with controlled dielectric by some PCB designers. IPC 2141 Trace Impedance Calculator. PCB stackup calculator. PCB impedance and loss-planning tutorial. It provides vital information like material thickness and copper weights. I use Saturn PCB Design ToolKit -> Conductor. We selected an 8-mil track width and spacing for the differential pair. Place SMT. PCB. This microstrip impedance calculator gives you a good start for estimating the trace width and PCB dielectric thickness that will produce a target impedance value. Layer 5 - Ground. The tool also calculates signal losses of any given trace. Panel size. You’ll also have access to an. Land on the best stackup by getting precise data, including: dielectric thicknesses, copper weights, layer order, impedance layers and reference layers. For thicker boards, the diameter is > 6 mils. It is widely accepted that the most accurate impedance calculations are produced with a 3D field solver due to the complex geometry in any PCB layout. Bittele Electronics Achieves ISO 13485 Certification; Bittele speeds up its quick-turn pcb assembly service;This calculator uses the frequency, either entered or calculated from risetime, to find the full wavelength in air and divide from that. 2. Controlled impedance. The Impedance Calculator evaluates single-ended and differential impedance for various impedance models. 0. Hence, there is a lower chance of contamination or corrosion. zigzag routing is one simple way you can improve impedance uniformity without adding any extra cost for the PCB itself. A cross-hatch plane is shown in the image below. A PCB impedance calculation generally refers to the task of calculating trace impedance, or transmission line impedance, based on the stackup and material configuration used in your design. 1. The design requires controlled impedance traces. Figure 2. Accurately model PCB pressed thickness using ITEQ's up-to-date library of spread weave prepeg and core constructions. Regarding the impedance of USB signal traces the layout guidelines state: DP, DM Differential trace impedance = [DP(45ohm) + DM(45ohm)] = 90 ohm, and do not jump the DP DM signals that cause impedance miss match. PCB Multi-Layer Stack-Up; PCB Design and Layout Guidelines; Basics of Control Impedance; Search articles: « Older Posts. 19mm) traces with 7. Get the answers to your questions about High Density PCBs with our FAQs from Sierra Circuits, the leading HDI PCB manufacturer in. 5 techniques to reduce ringing in PCB designs. IPC 2141 Trace Impedance Calculator. An HDI PCB stackup does not require a specific number of layers. Link to PCB stackup Speedstack enhanced with Projects; Via stub checks; Via pad/antipad coaxial calculation . It gives the measurement of the amount of signal degradation when the signal travels from the driver to the receiver. PCB constraint settings are necessary for a successful board design. The build-up provides the following information: The copper thickness and weight. 008” to 0. 05 vs 4. 6 for 7628) 3313 thinner prepreg between top layer and inner layer (0. Many of the design choices PCB designers make are in order to maintain good signal integrity. 1. Speedstack PCB Stackup Design and Documentation . In other special cases or Advanced PCBs (you need to choose " Additional Options" and custom stackup or control impedance): 1. This allows them to meet the above constraints—controlled impedance, crosstalk, interplane. An ideal 6-layer stack-up is shown in. Testing and examining a PCB after manufacturing is a pivotal factor in procuring a flawless design. Add a damping resistor near the source. I followed some guidelines online and read forums. It also has a major impact on the EMC performance of a product. 1 mil when tracks are inside.