For the PCB design engineer today, there is a lot that needs to be considered when creating a PCB design. Getting a good PCB with accurate controlled impedances needs a proper selection of PCB material and control of dimensions such as trace thickness, trace width, and dielectric thickness. Using the built-in Simbeor ® impedance calculator, the PCB editor's Layer Stack Manager calculates the trace width needed to deliver the specified impedance. 4mm to 3. The common ones are: single-ended characteristic impedance = 45/50/55/60 ohms, differential characteristic impedance = 85 /90/100 ohms. Launch Stackup Pro Iteq Home. Use impedance calculation tools for specific dimensional values based on your design requirements. To be successful, they require a thorough understanding of the fabrication process of the PCB and the materials used therein. The standard tolerance for controlled impedance is ±10%. 01) and dielectric constant (3. Here is my layer stack up image with thickness of dielectric between the copper layers. For those who are new to multilayer PCB stackup planning, standard 2 to 16 layer stackups have been provided that are commonly used. PCB Laminates & Materials Quick Turnaround Program; Why. Introducing the industry's first 3D web-based printed circuit board stackup design tool. When selecting a multilayer stackup we should consider the following: • A signal layer should always be adjacent to a plane. 3. It is the ratio of voltage and current amplitudes of a single wave propagating along the line in the absence of reflections from other directions. PCB Layer Calculation and Documentation Tool User Guide . Ansys RedHawk. Select the number of substrate layers. best to use a stackup calculator to provide quick ‘what if’ analysis of the possibilities. zigzag routing is one simple way you can improve impedance uniformity without adding any extra cost for the PCB itself. 2mm. The PCB layer stack-up calculator is a powerful tool for modern electronics design. FYI, I followed 2nd option and values were quite similar. TOP - SIGNAL L2. The IPC-2141 trace Impedance calculator will help make initial design easier by allowing the user to input basic parameters and get a. An impedance table should also be included in the fab drawing. It is challenging to identify the ideal material to facilitate high-speed and HDI applications. Accurately model PCB pressed thickness using ITEQ's up-to-date library of spread weave prepeg and core constructions. The following is the usual stackup information(4,6,8 layer PCB standard stackup), which also can be used as stackup of impedances. PCBCart's Standard PCB Layer Stack-up. Formulas from IPC-2141A Design Guide for High-Speed Controlled Impedance Circuit Board. Using a power plane as signal reference. It helps you achieve customized electrical, thermal, and. The characteristic impedance of your microstrips is determined by the trace width for a given layer stackup. Sierra Circuits is capable of fabricating circuit boards with a tolerance of ± 5% for controlled impedance. The Impedance Calculator is a tool which allows a quick pre-layout estimation of several kinds of line impedances between different layers. During this process, you must analyze and improve board elements such as stack-up, trace, vias, components, and others to ensure zero defects in the layout. Simpler calculators will use the less-accurate IPC-2141 equations. Use an impedance calculator when planning out your stackup to set up fixed impedance controlled trace widths later on. Multilayer PCB Stackup Planning by Barry Olney | In-Circuit Design Pty Ltd |Australia This Application Note details tried and proven techniques for planning high speed Multilayer PCB Stackup configurations. Signal problems can abound when trace width values are. Altium Designer includes a PCB trace impedance calculator, PCB trace width calculator under IPC 2152, and a plethora of other important design tools. Gerber files. The stack-up operator places the copper foil (layer 4 in the above image) and prepreg sheets on a heavy steel base plate. You will need the following information to then obtain certain parameters such as dielectric thickness etc to estimate your 50 Ohms impedance : Work out if you can the required PCB stack-up for the 6-layer PCB. Design for testing (DFT) evaluates the board’s accuracy based on functionality and manufacturability. ShareThe number of layers is one of the crucial factors in designing HDI boards. Achieving a critically damped state in the transmission line is crucial to achieving the fastest settling time without overshoot or oscillation. To estimate the cost of your PCB design optimization, you can use a PCB design software tool, such as KiCad. For a standard thickness 6-layer PCB, typical values are 0. The manufacturer will test the impedance on a test coupon. IPC-2152 is the standard for determining the current capacity, temperature rise, and width of a trace in a printed circuit board. 6. Layer 2 - Ground. For Si engineers & PCB technologists. 01) Speedstack PCB Layer Stackup Design Software bundles – Please note the following packaged software combinations: Speedstack PCB 2022. 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. Follow IPC-2220, IPC-2226 standards if you. A lower layer count may increase board size, routing complexity, and the inability to create high-density circuitry. Notice that there is no impedance information on the stackup drawing. The 1+N+1 stack-up is the simplest one without microvias. Si9000e – PCB insertion loss field solver. This was a four-layer flex board with ZIF connectors requiring controlled impedance. PCB constraint settings are necessary for a successful board design. 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 "). For PCB fabricators, Speedstack PCB interfaces with the industry standard Polar Si8000m PCB Controlled Impedance Field Solver. The Speedstack MaterialsThe PCB is designed and formed as a stack of layers. In other words, for proper impedance control, the load impedance must be equal to the characteristic impedance. 5mil clearance on a 63 mil board (1. A PCB's impedance depends on trace geometry, materials, and layer configuration. Some fabricators can advise on track geometries if you supply them with your preferred stackup. 8. In order to maintain the impedance, I would like to use a power plane as reference beneath the signals, instead. Powerful impedance design system;. • Ground planes must not be broken in the GND reference layer immediately beneath he transmission line. Using this technique, you can combine both analog (RF) and digital circuits onto a single board. Therefore via stubs should definitely be reduced in length below 0. Just Try "Saturn PCB Design" tool (FreeWare). . The dielectric constant of air is 1,and the dielectric constant inside the pcb stackup is usually 1. Their hardware design guideline said the traces between the USB and the termination resistors should have a differential impedance of 90 ohms. This is an 8-layer HDI PCB with a 48 mil total thickness. email: polarcare@polarinstruments. 7mil) / Track Gap 8 mil / Dielectric thickness 2x 0. 5(double-sided PCB) 7628 Prepreg 4. This is an 8-layer HDI PCB with a 48 mil total thickness. (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. Once these decisions are made, a designer needs to determine the PCB trace width required to hit their required PCB transmission line impedance. A typical value of 1/7 Lambda has been set by default. Stackups must be kept symmetrical, so there must also be 4 mils of dielectric between layers 7 – 8. Hence, there is a lower chance of contamination or corrosion. A few of them are summarized below. This dense board with high-speed components will need a multilayer PCB stackup. 24 hours a day, 7 days a week. Consider High-Speed Signal Frequency Range in PCB Stackup Design. The thicker the PCB stiffener is, the more support it will offer. Standard 4-Layer Stackup. 2 and a Df of 0. Different copper profiles in PCB. If a signal encounters impedance discontinuity, it will generate jitters in PCBs and hampers the signal integrity. An HDI PCB stackup does not require a specific number of layers. 15 mm min track/clearance/annular ring and 1. On a multilayer PCB this only works when the signal is also on an inner layer-- making it difficult to have the proper impedance AND capacitance on an outer layer. Case 1: 8-layer HDI board design specifications. 2. Call us: +1 (800) 763-7503 Email us:. Select the number of substrate layers. First, select the desired RLC connection (parallel/series). Sierra Circuits can assist you in designing your flex stackup. 4-Layer Impedance Control Stackup. Be warned though! The calculators only give you estimates, your board has. PCB Impedance-Calculation: Help with the dimensioning of the impedances of your circuit board. Changing the stack-up will affect the calculated trace width for impedance-controlled traces; however it will not automatically update existing traces. High-density interconnects (HDI) PCBs are the boards with a higher. In both cases, you’ll need to enter your stackup information into the calculator to get accurate results. 3. Achieving a. An RF PCB design is a bit different from a conventional board. Trace simulations were made using CST, and at first, I simulated the s-parameters of each trace by adding ports for each trace. 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. My Total PCB thickness is around 1. AP537. The stack-up designates the materials to be used for the manufacture of a multilayer circuit board. The stackup used to build a real circuit board is a major determinant of signal integrity and power integrity. FYI, I followed 2nd option and values were quite similar. Dielectric material (partially cured) is used to bond copper cores and copper foil in the layer stack-up. IPC 6012 CLASS 3/ES. You will typically want to include the following information: Trace width you’ve determined for a required single-ended impedance. for example, with a layer-height of 0. A hybrid stackup construction enhances your PCB’s performance and cost-effectiveness by combining different materials or technologies. 265mm core between the top-layer and the second (GND plane) layer, each using 0. Reduced space and weight. 2) Microstrip without side ground is fine. While this calculator will provide a baseline, any final design considerations should be made towards loss, dispersion, copper roughness, phase shift, etc. Stick to these design rules when you’re designing your stack-up. Simons, "Coplanar Waveguide Circuits, Components, and Systems", Wiley. Atlas DRG v18. PDN impedance is one of those critical concepts in high speed PCBs, but many designers leave it as an afterthought. Coplanar Waveguide Calculator. The cost index provides a relative idea of the cost compared to another layer order. Stackup design is the arranging of the signal and power layers of a PCB to meet the electrical and mechanical performance needs of a specific design. MAN 199–2002I want to learn something about desiging a custom PCB stackup. Modeling approximation can be used to design the microstrip trace. 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. Tighter bends increase circuit damage. Allegro PCB Designer. It is a full-featured Excel-based tool that helps plan the PCB stack-up so that controlled impedance traces can be effectively implemented. Make sure you understand the factors that influence transmission line impedance , and. Dimensions. The ratio of cross-hatch conductor width (HW) to cross-hatch pitch (HP) plays an important role while characterizing the cross-hatch plane. PCB layer count estimation is a vital process in board manufacturing and cost. Going to route the following signals: 100R differential pair (Zo = 50R) 90R differential pair (Zo = 45R) Planning to use the stack up JLC7628, with a 4 layer PCB, in total 1. You have this backwards, the common rule is to use impedance control when the electrical length of the trace is more than 1/10 of a wavelength at the frequency of interest. Track width (w) = 137 micron. 6 mm PCB thickness, but is this the final thickness, after lamination or before ? Also what's the margin on this thickness. Stackup design, PCB impedance calculations, and Altium Designer's involvement in high-speed impedance control are covered in detail in this article. Impedance Calculator Trace Width, Current and Temp Rise Calculator Better DFM BOM Checker PCB Material Selector PCB Stackup Designer Talk to a Sierra Circuits PCB Expert today. Controlled. For example, in the image above, layer L10 in the stackup is enabled for impedance calculations, with the Top Ref set to 9-L9, which is a Plane layer,. The Layer Stack Manager dialog allows you to configure the layers of the board. 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. Make sure you use an accurate tool like this before you start building your stackup as this can help you identify the best laminate materials to use for your target impedance and. Hybrid PCB stack-up: Stack-up made up of Rogers 4350 and Isola 370HR material for high-frequency circuits. ) Hide We may add extra cost for these special options which will be confirmed after review. 6 for 7628) 3313 thinner prepreg between top layer and inner layer (0. Contents. Learn more about the integrated field solver from Simberian in Altium Designer. For components running at 5 V or 3. Thank you. 4mil (1 oz) for plane layers. Enter the relative permitivity, width of the trace, the ground plane spacing, and the substrate thickness to calculate the characteristic impedance. If you are planning to build an IPC class 3 board, ensure that the. 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. If you want your circuit board to be thicker, you will have to use polyimide stiffeners. These files are utilized for the PCB manufacturing and assembly process. Most CAD systems provide an impedance. 2 Foreword the theoretical, but also the practical elements. 002” to 0. This is done in the PCB editor's Layer Stack Manager. L1=Ground, L2=signal/transmission lines, L3=signal, L4=Power. ] [Start with stack up from you preferred PCB supplier. The stackup drawing must contain more information than in the past, and the fabrication notes will need to be expanded. 623134. 3. By controlling the PCB impedance, unexpected damages or errors can be limited to some extent. Note that they have other board thickness and copper thickness variants available. Used by PCB manufacturers to refer to selection of dielectrics and thicknesses to hit a trace width/spacing specification, or modification of trace geometry, to hit an impedance target. 125. Calculating rise time and propagation delay is important to carry out the impedance measurements. In other special cases or Advanced PCBs (you need to choose " Additional Options" and custom stackup or control impedance): 1. Microstrip Impedance Calculator. As a rule of thumb, a four layer board will produce 15 dB less radiation than a Double side PCB board. A fully unified, heavily rules-driven PCB design platform for impedance controlled routing in high-speed PCB design. Currently, the maximum width is set to 10 mil, but I normally set this to 5% higher than. Hot Network Questions Fixing wrong ideas about coefficients (e. The surface finish is neglected. Planes, in Multilayer PCB’s, provide significant reduction in radiated emission over two layer PCBs. 1. 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. Layer 5 - Ground. My design constraints would be sticking to a 2 layer 100 mm x 100 mm PCB with 0. T= Experimental temperature. 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. Controlled Stackup. core materials is easiest when you use PCB design software with an integrated stackup and impedance calculator tool. PCBCart provides multilayer circuit boards with layers in the range from 4 to 32 layers, board thickness from 0. Cross-hatched copper plane in a flex stack-up for controlled impedance. Use 7. I am planning to have the PCB (4 layer) manufactured at JLPCB controlled impedance service. Here’s the list of 10 most used EDA tools (in alphabetical order). com We recommend the software from Polar Instruments if you want to get exact impedance calculation. Planning the multilayer PCB stackup configuration is one of the most important aspects in achieving the best possible performance of a product. Microstrip allows for thinner flexible PCB design (2 layers with a thin core), whereas stripline increases flex thickness considerably (3 layers with 2 thicker cores). Email us: through our Customer Care form. Designers can utilize layer stack management and routing to control board impedance. It renders accurate results suitable for use in circuit board manufacturing and. PCBWay manufactures multilayer circuit boards with layers in the range from 4 to 14 layers, board thickness from 0. 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. Layer 6 - Signal/Power. 87 mil) is nominal thickness of 7628 prepreg. For your convenience, we have designed a Impedance Calculator to help you calculate the impedance and trace width you need. When defining reference planes, both with impedance controlled routing and in managing return paths, your stackup might force return currents to pass into a PCB power plane before being coupled back to a. Technical Report. 5oz to 6oz), inner layer copper thickness from 18μm to 70μm (0. Stress Vs. [2] Calculate the top layer signal end impedance: Two tools are giving Zo=48 and Zo=47. Following images present PCBWay's default layers stack. The stack-up designates the materials to be used for the manufacture of a multilayer circuit board. Procedure to use the calculator: 1. 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. Similar to the Saturn tool, this capability allows you to experiment with the stackup and track dimensions to estimate impedances. An example of rigid-flex PCB stack-up. IPC 2141 Trace Impedance Calculator. This calculator allows you to add the impedance model and compute the. Stack-up and grounding. Just as an example, we can look at a simple PCB stackup with impedance control to see the microstrip inductance. Testing and examining a PCB after manufacturing is a pivotal factor in procuring a flawless design. 2 of the Microstrip Calculator, h=H1 and b=H2-H1. Controlled Impedance routing is all about configuring the dimensions of the routes and the properties of the board materials to deliver a specific impedance. It gives the measurement of the amount of signal degradation when the signal travels from the driver to the receiver. Board designers can focus on reducing via diameter to enhance routing. = room temperature (25⁰C) L= Length of trace. PCB layers affect electrical performance, signal integrity, and product cost. Any discontinuity at any point will affect the uniformity of the characteristic impedance and cause reflections. Solder a jumper or a wire to repair the trace. Used interchangeably with controlled dielectric by some PCB designers. HDI stack-up: 16-layer board with through-hole, buried and staggered blind vias ITEQ Stackup Pro TM. g. PCBCart provides multilayer circuit boards with layers in the range from 4 to 32 layers, board thickness from 0. Via stitching is implemented for various reasons. Microstrip Impedance Calculator. 2mm (7. Stack-up is an arrangement of board materials in sequential order. . Comprises Speedstack PCB Layer Stackup Design and Documentation tool and Si8000m PCB Impedance Field Solver. 623134. Connections are formed in the copper layer (s) as conductive traces by etching away (removing) unwanted copper. PCB. 5 oz. The stackup drawing must contain more information than in the past and the fabrication notes will need to be expanded. To elaborate, the number of layers on top of the core should be equal to the layers on the bottom. This paper presents a flexible and efficient methodology to optimize stack-up for multi-layer printed circuit boards (PCBs) with enormous search space and various design constraints. This application note is intended to assist customers in de signing a PCB using Microchip’s family of 10/100/1000 Mbps. As we know, laser stands for light amplification. Eurocircuits’ PCB DEFINED IMPEDANCE pool is a fast turnaround solution for PCB’s with a specific impedance requirements for certain tracks. 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 build-up provides the following information: The copper thickness and weight. • The typical PCB stack-up uses a signal layer on the top (component side) layer, a solid, contiguous ground plane. The ratio of cross-hatch conductor width (HW) to cross-hatch pitch (HP) plays an important role while characterizing the cross-hatch plane. Use Saturn PCB's toolkit with the "Differential Pairs" tab. Altium Designer. 29 relative dielectric constant. In both cases, you’ll need to enter your stackup information into the calculator to get accurate results. 5. Complex PCB requirements; Mil-Spec & Class 3 with HDI Features; Blind &. Impedance control is a critical consideration when designing and manufacturing printed circuit boards (PCBs) used in high speed or high frequency applications. Thank you. 4 mil (1 oz finished thickness), respectively. 10 layer PCB stack-up . 4, that's why there is a difference in impedance values of microstrip and stripline. layout impedance. mm. and also to JLCPCB’s impedance calculator for their stackup. Panel size. ALTIUM DESIGNER. It works in parallel with the standard PCBS layer stackup manager and gets the default setting from it. 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. Dielectric constant = 3. HDI PCB stackup with staggered microviasSignal Integrity (SI) in High-Speed PCB Designs. The preferred equation used for calculating impedance is repeated here in Equation 1. Unit: Options are mm, mil, μm, and inch. they normally use 7. Converts short and long line . Modified 2 years, 4 months ago. Sierra Circuits follow this. 3 How to calculate the average effective. 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. Learn more about the industry’s best field solver built into your PCB stackup calculator. 1 Defining cores and prepregs 2. Calculating Impedance in PCB Stackups. Single ended. There are in general two approaches to create a PCB stackup, known as controlled stackup and controlled impedance. Traces and their stack-up are presented in Figure 7. 2. Enable the Stack Symmetry option in the Properties panel. Vias (plated holes) are used to route electrical signals among different layers of a multilayer. Phone: +44 (0)1425 489 111 / +49 (0) 8104 628 0. Since it directly references the stackup information and has a. The PCB stackup you create for a high speed circuit board will determine the impedance, as well as ease of routing. Higher data rates/faster edge rates are more prone to failure due to errors that are inherent in using simple calculator applications and an online calculator. This will also affect the. as i think it can do. Adhering to these standards enables your manufacturer to establish a. However, the max width is still adjustable. There are some advantages to using a microstrip transmission line over other alternatives. The material thickness between layers 1 – 2 should be 4 mils, max. The build-up provides the following information: The copper thickness and weight. You can use specialized PCB design tools or calculators to determine trace impedance accurately. Note: The results are only for approximation and rough estimation, the final values and the. For the assembly process, manufacturing data is also required. IPC-A-600 Inspectors. I'hv already checked on Saturn PCB Design tool. Gnd plane is also well connected (I carved the PCB to make sure vias connected to it). If you need custom FPC stackup, please make note and we will manufacture according to your requirement. See full list on resources. Optimize your class 3 stack-up for signal integrity. PCB Trace Width Calculator; PCB Shelf Life; Capabilities PCB Capabilities PCB Assembly Service Quick turn PCB Fabrication. Circuits can: Help you with your controlled impedance stack-up. Initial stack-up of the 8-layer board. 2 (double-sided) Flex thickness x 12. Wavelength calculator Calculates the wavelength of a signal using Ereff. Place SMT. In a traditional PCB design, the designer specifies the width/clearance of the trace to satisfy the current/voltage requirements. 24 hours a day, 7 days a week. Impedance matching is the way of configuring the input impedance of a load or the output impedance of its signal source. In a controlled impedance design the designer specifies the impedance rather than the trace width. Length of both tracks should be the same. Cross-hatched copper plane in a flex stack-up for controlled impedance. PCB stack-up design. The PCB stack-up has eight layers, with controlled impedance traces on layers 1, 2, 6, and 7. Speedstack Si includes Si9000e. This tool calculates the impedance of a conductor based on various inputs and circuit type. While this calculator will provide a baseline, any final design considerations should be made towards loss, dispersion. The microstrip is a very simple yet useful way to create a transmission line with a PCB. An example of hybrid stack-up with Rogers and FR-4. Our Impedance Calculator is based on 2D numerical solutions of Maxwell’s equations for PCB transmission lines. The Simbeor SFS. Since it directly references the stackup information and has a. Speedstack is the stackup design tool of choice for professional PCB Designers fabricators and brokers who have a requirement to document and design stackups drill plans and material requirements complete with high speed transmissionline information. The ‘ripple%’ points to the maximum voltage deviation. Performing a PCB design review will help you identify and rectify these errors. Planning Your High Speed PCB Stackup and Impedance. 1. Layout engineers will design the layout based on the stack-up design, including settings such as line width, line spacing, and differential routing. Using an online differential impedance calculator, the height of the dielectric layer, h, is needed. For instance MacroFab's stackup state a 1. 5 techniques to reduce ringing in PCB designs. Modeling approximation can be used to design the microstrip trace. Controlled impedance: There can be a slight variation in the specified and manufactured impedance values. It is a full-featured Excel-based tool that helps plan the PCB stack-up so that controlled impedance traces can be effectively implemented. Via stitching on a circuit board layout Designing via stitches for high-current PCB layout. This tool allows you to create, edit, and simulate your PCB design, and provides. 01) and dielectric constant (3. Consider the following points to limit the flexible PCB errors in the bend areas: Avoid 90-degree bends. IsoStack ®. Historically, the primary electrical requirements have been a controlled impedance in the signal layers and enough copper in the plane layers to deliver DC power to the circuits mounted on the PCB. 2. The dialog can be used in two modes: Simple or Advanced. Differential pair into PCB calculator. A schematic diagram is a representation of the elements of a system using abstract and graphic symbols. Route signals to ensure the return path is directly underneath the signal trace. (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. I am designing a USB-hub that has many USB traces. JLCPCB Impedance Calculator. This note provides a brief look at how stackups have progressed from the single sided PCB to HDI builds with their multiple layers and multiple passes through the production process. PCB Stackup Designer Talk to a Sierra Circuits PCB Expert today. An impedance calculator is integrated within this tool which you can use to compute the necessary impedance, trace width, and spacing values for any signal layer. ; 2. To access these features, simply open your layer stackup in the PCB Editor and click on the Impedance tab. Allegro ® layout editors – Allegro ® PCB Editor and Allegro ® Package Designer Plus – include a spreadsheet-based user interface, Cross-section Editor to help you define an accurate layer stackup with. If it is different, you need to increase the length of shorter track to match with the longer track. It should include impedance value, trace width, differential pair spacing, and the layer on which the controlled impedance traces are routed.