337-086-559-202

FAQFrequently Asked Questions

• Can the Mercury 337-086-559-202 86-position card edge connector handle both single-ended and differential signal transmission without crosstalk issues? The 337-086-559-202 features a dual-row, 43 positions per row configuration with 0.156" pitch spacing. For differential pairs, the physical separation between rows (dual-edge layout) means signal and return paths are not immediately adjacent on the same row. This spacing can introduce loop area and increase susceptibility to crosstalk compared to tightly coupled differential designs. Single-ended signals benefit from the dual-row ground distribution available in the 2-row layout. Design-in assessment should account for signal integrity requirements; high-speed or low-noise applications may require careful layer stackup planning and controlled impedance routing to companion PCB traces.
• What card thickness tolerance should my PCB design target for reliable engagement with the 337-086-559-202 connector? The Mercury 337-086-559-202 specifies a card thickness range of 0.054" to 0.070" (1.37mm to 1.78mm). Manufacturing tolerance stack-up for your PCB should center around this window to ensure consistent cantilever contact pressure across all 86 positions. If your PCB thickness falls outside this range, contact force may become insufficient at the extremes, leading to intermittent connections or elevated contact resistance. FR-4 material and plating thickness should be accounted for when calculating final board thickness. During prototyping, sample boards at both tolerance limits should be tested for insertion force and contact resistance stability.
• How does the 0.156" pitch of the 337-086-559-202 compare to standard 0.1" pitch connectors when migrating from older card cage designs? The 337-086-559-202 uses 0.156" (3.96mm) pitch, which is coarser than the common 0.1" (2.54mm) DIP pitch. This coarser pitch reduces PCB layout density but improves noise immunity and mechanical robustness for through-hole wire-wrap termination. Migration from 0.1" pitch designs to the 337-086-559-202 requires complete PCB redesign; direct 1:1 porting is not possible. The 0.156" spacing provides better isolation for analog or mixed-signal applications but occupies more board real estate. Alternative 0.1" dual-edge connectors exist in the market; trade-offs include reduced clearance margins and increased assembly complexity for wire-wrap termination.
• Is the wire-wrap termination of the 337-086-559-202 suitable for automated assembly, or does it require manual termination? The Mercury 337-086-559-202 is specified with wire-wrap termination, which is traditionally a semi-automated or manual process. Modern wire-wrap equipment can process this connector, but the dual-row, 86-position density and right-angle through-hole mounting require careful fixturing and programming. Most contract manufacturers performing wire-wrap on the 337-086-559-202 use semi-automated systems with manual positioning. Lead times for wire-wrap assembly may be longer than soldered termination alternatives. If production volume is high and turnaround critical, evaluate whether a compatible card-edge connector with solder-tail termination (such as similar pitch designs from other manufacturers) would reduce assembly time and cost, accepting differences in contact redundancy and insertion force characteristics.
• Can the 337-086-559-202 be used in a hot-swap or hot-insertion application without damaging the connector or circuit? The 337-086-559-202 does not include any special shielding, sequencing, or keyed-insertion features to manage hot-swap transients. Dual-edge, cantilever-contact designs rely on wiping action during insertion to clean contact surfaces, but they do not prioritize ground connection sequencing. Hot-insertion of the 337-086-559-202 into powered backplanes can expose the connector to bus contention, voltage spikes, or ground bounce if signal and power planes mate unevenly. For applications requiring hot-swap capability, alternative connectors with staggered ground pins, keying features, or contact sequencing should be evaluated. If the 337-086-559-202 must be used in hot-insertion scenarios, external surge protection, current-limiting series resistors, or isolation logic on each signal is advisable.
• What is the expected contact resistance range for the 337-086-559-202 connector, and how does it drift over temperature cycling? The 337-086-559-202 specifies gold-plated cantilever contacts (10.0µin / 0.25µm finish) on copper alloy. Gold plating of this thickness provides corrosion resistance and low initial contact resistance, typically in the range of 10–50 milliohms per contact for dry matings. Contact resistance can vary with mating cycles and wiping action; initial insertion establishes a contact film. Over temperature cycling from -40°C to 105°C, copper alloy exhibits thermal expansion that may alter contact pressure, potentially increasing resistance by 20–40% at temperature extremes relative to room-temperature baseline. For precision current-sense circuits, analog signal chains, or high-frequency applications, allowance should be made for contact resistance in the system budget, and periodic re-mating or maintenance cycles may be necessary in harsh industrial environments.
• Is the 337-086-559-202 suitable as a replacement for older mercury-wetted card-edge connectors, or does the design differ fundamentally? The Mercury 337-086-559-202 is a dry-contact, gold-plated cantilever connector and should not be directly equated to mercury-wetted designs used in legacy equipment. Mercury-wetted connectors offer lower and more stable contact resistance under vibration and thermal cycling due to the liquid metal interface, whereas the 337-086-559-202 relies on mechanical contact force and surface finish. Replacement of mercury-wetted connectors with the 337-086-559-202 is technically feasible if the 86-position, dual-row, 0.156" pitch footprint aligns, but system performance characteristics will differ. Measured contact resistance will be higher and more variable; current-carrying capacity and temperature stability may require circuit redesign. Testing and validation of the replacement design under actual operating conditions is necessary before field deployment.
• What solder-tail or cabling alternative exists if wire-wrap termination of the 337-086-559-202 is not compatible with my production line? The 337-086-559-202 is specified with wire-wrap termination only; no solder-tail or through-hole pin variant is listed in standard catalogs from Mercury. To use an 86-position dual-edge connector with solder termination, alternatives from other manufacturers (e.g., TE Connectivity, Samtec, or Amphenol) offering similar pitch and position counts should be evaluated. These alternatives may differ in contact geometry, insertion force, contact resistance, or flange design. If wire-wrap is the limiting factor, custom transition boards or backplane designs using off-board wire-wrap modules can be considered as a workaround, though this adds cost and complexity. Direct substitution is not recommended; each alternative requires mechanical re-validation and electrical re-characterization.
• How should the 337-086-559-202 connector be protected from moisture and contamination in outdoor or marine environments? The Mercury 337-086-559-202 is specified as green polyester thermoplastic insulation with no conformal coating or sealed cavity design. The dual-edge, top-opening flange design allows moisture ingress between card and connector body if exposed to rain, spray, or high humidity. Moisture Sensitivity Level (MSL) is listed as Not Applicable, indicating the connector itself does not absorb significant moisture during storage, but the mated interface is not sealed. For outdoor or marine use, the connector should be housed within an IP65 or higher-rated enclosure, or a protective boot or cover should be fitted over the card edge. Periodic visual inspection and contact cleaning (dry compressed air, isopropyl alcohol) should be performed in marine or high-contamination environments. Long-term exposure to salt spray will degrade the gold plating, requiring accelerated maintenance cycles.
• Can the 337-086-559-202 support high-frequency digital or analog signals without impedance-controlled routing, and what bandwidth limitations should I expect? The 337-086-559-202 is a passive connector with no active filtering, impedance matching, or shielding built in. The dual-row, 0.156" pitch layout and right-angle through-hole mount create distributed inductance and capacitance. Without controlled impedance design (stripline or microstrip with matching termination resistance), the connector introduces reflections and attenuation on signal edges. For baseband signals below ~10 MHz, these effects are typically negligible. For digital signals in the 10–100 MHz range or analog signals requiring <1% THD, impedance-controlled design rules (trace width, clearances, layer stackup, termination resistors) should be applied. Serial digital interfaces (like LVDS or Ethernet) routed through the 337-086-559-202 require careful length matching and may suffer eye closure or jitter unless the complete signal path is optimized. Empirical measurements (TDR, eye diagrams, or S-parameter testing) of prototype assemblies are advisable for high-speed applications.
• What is the maximum current per contact for the 337-086-559-202, and does it vary with contact plating or operating temperature? The Mercury 337-086-559-202 datasheet does not explicitly specify maximum current per contact; copper alloy with 10.0µin gold plating typically supports 1–3 amperes per contact in steady-state, depending on acceptable voltage drop and thermal rise. Contact resistance (typically 10–50 milliohms) dissipates heat (P = I²R); at 2 amperes, a 30 milliohm contact produces ~120 mW of heat. Operating temperature range is -40°C to 105°C; at the upper limit (105°C), contact resistance may increase 20–40%, further raising dissipation. For applications requiring >1 ampere per contact, use multiple contacts in parallel for the same signal, or validate actual current capacity through testing. High-current applications (e.g., backplane power distribution) are better served by dedicated power connectors with lower contact resistance and higher current ratings.
• How does the 337-086-559-202 perform in vibration-prone environments such as aerospace or transportation applications? The 337-086-559-202 is a through-hole, right-angle mounted connector with cantilever contacts. During vibration, the card edge experiences micro-motion relative to the connector body, causing mechanical fretting that can degrade the contact interface and increase resistance. Vibration testing (MIL-STD-810 or equivalent) is not specified in standard product documentation. Cantilever contacts are inherently more compliant than compression contacts, offering some shock absorption but also greater susceptibility to intermittent contact loss under extended vibration. For aerospace, transportation, or defense applications, qualification testing under relevant vibration profiles (frequency sweep, acceleration limits, duration) should be performed on prototype assemblies. Backplane design should include retention latches, shock-mounting, or conformal coating to mitigate vibration-induced wear. Long-term field reliability in vibration environments is not well-characterized for the 337-086-559-202; empirical data from similar applications should be requested from the manufacturer.
• Is the 337-086-559-202 compliant with RoHS and REACH regulations, and does this affect long-term supply or design lock-in? The Mercury 337-086-559-202 is marked as ROHS3 Compliant and REACH Unaffected, indicating compliance with EU Restriction of Hazardous Substances (RoHS) Directive 3 and no restriction under REACH (Registration, Evaluation, Authorization and Restriction of Chemicals). This certification allows the connector to be used in new designs and exported to EU markets without restriction. ROHS3 compliance means no lead, cadmium, hexavalent chromium, or other restricted substances above threshold limits. The gold plating and polyester thermoplastic insulation meet these criteria. Supply chain lock-in is not immediately imposed by RoHS/REACH status alone; however, if the connector becomes obsolete, alternative compliant designs may have different performance characteristics. Verify with the manufacturer that no end-of-life notices are planned in the next 5–10 years if the design is intended for long-term production.
• What are the differences between the 337-086-559-202 and other variants in the Mercury 337 series, and how do I choose between them? The Mercury 337 series includes variants differing in position count, card type (single or dual edge), contact finish, termination method, and flange features. The base product number is 337-086, which denotes 86 positions. Variants within 337-086 include different suffixes (e.g., 559-202) designating specific configurations: gold plating, wire-wrap termination, green insulation, and dual-edge layout. Other variants in the 337 family may offer 50 or 72 positions, solder termination, or nickel plating. Selection depends on board layout constraints (position count, pitch), assembly process (wire-wrap vs. solder), reliability requirements (contact finish, vibration rating), and cost. The 337-086-559-202 is the standard dual-edge, 86-position, gold-plated, wire-wrap version; if this does not align with your requirements, consult the Mercury 337 series datasheet or distributor for compatible alternatives.
• Can the 337-086-559-202 be retrofit into existing backplane or cage designs that originally used a different connector type? The 337-086-559-202 has a specific mechanical footprint defined by the 86-position count, 0.156" pitch, dual-edge layout, and right-angle through-hole mount. Retrofit feasibility depends on whether the existing backplane PCB layout and card-edge geometry align. If the original design used a different pitch (e.g., 0.1"), position count (e.g., 50 or 72), or card type (single-edge vs. dual-edge), direct mechanical substitution is not possible without PCB rework. Even if pitch and position count match, differences in flange height, contact force, or wiping geometry may cause mating issues or unreliable contacts. Field retrofit of the 337-086-559-202 into legacy equipment should only be attempted after dimensional verification, mating trial with representative cards, and contact resistance measurement. Full re-qualification testing is recommended to ensure backward compatibility and prevent field failures.