DW-24-20-F-D-855

FAQFrequently Asked Questions

• What is the stack height of the DW-24-20-F-D-855, and how does it affect PCB layout when used in multi-layer connector applications? The DW-24-20-F-D-855 has a stack height of 0.855" (21.717mm), which determines the vertical clearance required above the PCB. This dimension is critical when designing enclosures or when stacking multiple connector stages vertically. The stack height includes the header body itself, so you must account for this in your mechanical design to avoid interference with shields, heat sinks, or adjacent components. If your PCB space is constrained vertically, the DW-24-20-F-D-855's stack height may require repositioning of nearby through-hole components or routing adjustments.
• Can the DW-24-20-F-D-855 be directly replaced with a standard 2x24 0.1" pitch connector from another manufacturer? While the DW-24-20-F-D-855 shares the 0.1" pitch and 2-row, 48-position layout with many standard connectors, direct replacement depends on several factors. The DW-24-20-F-D-855 features a specific stack height of 0.855" and a 0.100" row spacing, which are Samtec Flex Stack series characteristics. Some competitors' connectors may have different stack heights, post lengths (the DW-24-20-F-D-855 has 0.165" mating post length), or tail lengths (0.110" for the DW-24-20-F-D-855), potentially causing seating issues or clearance conflicts. Additionally, the DW-24-20-F-D-855 uses gold plating (3.00µin thickness) on the mating post, which affects contact resistance and reliability in corosive environments compared to tin or nickel-plated alternatives. Before substitution, verify mechanical fit, post length compatibility, and electrical performance requirements.
• What design considerations apply when using the DW-24-20-F-D-855 in applications with tight PCB spacing or constrained board-to-board distances? The DW-24-20-F-D-855 is a 2-row, 48-position connector with 0.100" pitch, meaning the connector footprint occupies approximately 4.8" across the two rows (with row spacing of 0.100"). The 0.110" tail length requires adequate solder area on the PCB, and the 0.855" stack height limits how close you can position overlying components. In space-constrained designs, you may need to route traces between pins rather than under the connector body. If your application requires a more compact solution, consider whether a smaller pitch connector (0.050" or 0.080") or a right-angle variant would better suit your layout. The DW-24-20-F-D-855's vertical profile should be confirmed against your enclosure depth and any stacked daughterboards.
• How does the gold contact finish on the DW-24-20-F-D-855 affect long-term reliability in industrial or harsh environments? The DW-24-20-F-D-855 uses gold plating (3.00µin or 0.076µm thickness) on the mating post, which provides superior corosion resistance compared to tin or nickel finishes. Gold resists oxidation and maintains low contact resistance over time, making it suitable for applications exposed to humidity, temperature cycling, or mild chemical environments. However, 3.00µin is a relatively thin gold layer; in high-mating-cycle applications (frequent connect/disconnect), the underlying base metal may become exposed, reducing corosion protection. For harsh industrial settings with high vibration or thermal cycling, the DW-24-20-F-D-855's gold finish supports reliability, but you should still implement strain relief, proper seating force, and periodic inspection protocols. If your application involves hundreds of mating cycles, consider whether a thicker gold plate or an alternative contact finish (such as paladium or a harder composite) would extend service life.
• What is the mating post length of the DW-24-20-F-D-855, and does it accommodate standard receptacle connectors? The DW-24-20-F-D-855 has a mating post length of 0.165" (4.191mm). This dimension is critical for ensuring proper seating depth with mating receptacles. Standard 0.1" pitch receptacles typically accept post lengths between 0.125" and 0.200", so the DW-24-20-F-D-855 falls within the typical range. However, some specialty receptacles or high-density mating connectors may have tighter insertion depth tolerances. When selecting a mating partner, verify that the receptacle's insertion depth and contact geometry are compatible with the 0.165" post length to avoid undercutting, misalignment, or weak contact force. If you are designing a custom receptacle or using a non-standard mating connector, the post length specification of the DW-24-20-F-D-855 must be validated against the receptacle's cam profile and contact position.
• Is the DW-24-20-F-D-855 suitable for applications requiring frequent mating and unmating cycles? The DW-24-20-F-D-855 is designed as a header connector for through-hole assembly, typically intended for semi-permanent or fixed installations rather than continuous hot-pluging. The gold contact finish (3.00µin) provides some protection against wear, but the mechanical durability depends on the mating receptacle quality, insertion force, and number of cycles. If your application requires repeated disconnections (such as test fixtures or modular systems), evaluate the expected cycle count. For applications with more than 50-100 mating cycles, consider using a connector specifically rated for high-cycle reliability, which may include thicker gold plating, reinforced mechanical structures, or spring contacts designed for repetitive use. The DW-24-20-F-D-855 can support frequent mating in laboratory or field-service scenarios, but longevity will depend on proper handling, alignment during insertion, and the quality of the mating receptacle.
• How should the through-hole tails of the DW-24-20-F-D-855 be soldered to avoid solder joint failure during thermal cycling? The DW-24-20-F-D-855 has a tail length of 0.110" (2.794mm) for solder attachment. Proper soldering technique is essential to achieve reliable joints during thermal cycling, which stresses solder connections due to coefficient-of-thermal-expansion (CTE) mismatch between the connector body, solder, and PCB. Use solder reflow profile that minimizes thermal stress: ramping temperature slowly, avoiding excessive peak temperatures, and allowing adequate cooling time. Wave soldering is acceptable for through-hole connectors like the DW-24-20-F-D-855, but ensure that the solder bath temperature and dwell time are controlled to prevent solder bridging between adjacent pins or voids within the joint. Hand soldering is not recommended for 48-position connectors due to the high pin count and risk of incomplete wetting or cold joints. After soldering, inspect for adequate fillet formation and use X-ray inspection for high-reliability applications to verify solder penetration. If your application involves extreme thermal cycling (−40°C to +85°C or beyond), consider underfill or poting to reduce mechanical stress on solder joints.
• What are the RoHS and REACH compliance implications of using the DW-24-20-F-D-855 in products sold in different regions? The DW-24-20-F-D-855 is RoHS3 compliant and REACH unaffected, which means it meets the Restriction of Hazardous Substances Directive (RoHS) requirements for the European Union and does not contain substances listed on the REACH Candidate List of Substances of Very High Concern (SVHC). This status simplifies product compliance for markets requiring RoHS certification, such as the EU. REACH unaffected status means the connector does not trigger additional SVHC reporting or authorization requirements under EU chemical regulations. However, your complete assembly (PCB, solder, solder mask, and other components) must also meet RoHS and REACH requirements; the compliance of the DW-24-20-F-D-855 alone does not guarantee end-product compliance. When exporting to North America, verify whether your product must comply with US lead-free requirements (similar to RoHS) or California Prop 65 regulations, which are independent of RoHS/REACH status. Document the DW-24-20-F-D-855's compliance status in your bill of materials and compliance declarations.
• What is the electrical performance difference between the DW-24-20-F-D-855 and similar connectors with a0.050" pitch layout? The DW-24-20-F-D-855 uses a 0.100" (2.54mm) pitch, whereas 0.050" pitch connectors double the pin density in the same footprint area. Pitch selection affects several electrical parameters: 0.100" pitch connectors like the DW-24-20-F-D-855 have lower crosstalk due to greater spacing between signal traces, lower impedance variation, and better isolation in mixed-signal applications. 0.050" pitch connectors offer higher density but require tighter manufacturing tolerances, smaller trace widths, and increased routing complexity on the PCB. For high-speed digital signals (above 100 MHz) or analog precision circuits, the DW-24-20-F-D-855's 0.100" pitch reduces signal integrity issues. If your design includes both power and signal pins, the DW-24-20-F-D-855's spacing allows more flexible ground plane placement and power distribution. Conversely, if you need maximum pin count in minimal area, a 0.050" pitch connector may be more suitable, accepting the trade-off of increased signal integrity challenges and higher manufacturing costs.
• Can the DW-24-20-F-D-855 be used in applications with supply voltages above 24V DC? The DW-24-20-F-D-855 datasheet does not specify a maximum voltage rating for the connector itself, as the voltage-carrying capacity depends on the base metal, contact material, and spacing between conductors. Gold-plated copper contacts (as used in the DW-24-20-F-D-855) can safely carry voltages up to several hundred volts DC in non-arcing environments. However, the actual voltage limit depends on trace spacing on your PCB, crepage and clearance distances, and the intended application environment. For high-voltage applications (above 24V), conduct a crepage and clearance analysis per IEC 60664-1 to determine if the 0.100" pitch of the DW-24-20-F-D-855 meets safety requirements for your operating voltage and pollution degree. In humid or corosive environments, higher voltages may cause premature failure due to electrical tracking or corosion. For applications exceding 48V AC or 125V DC, consult with Samtec or your design team to confirm that the DW-24-20-F-D-855 meets dielectric withstand and safety agency requirements (UL, CE, etc.).
• What are the practical limitations of retrofitting the DW-24-20-F-D-855 into an existing design that previously used a Molex orTE Connectivity connector? Retrofitting the DW-24-20-F-D-855 into a design originally designed for a Molex (such as K 254) or TE Connectivity (such as Micro-Match) connector requires careful evaluation of mechanical and electrical differences. While many connectors share the0.100" pitch standard, they differ in stack height, post length, row spacing, and contact resistance. Molex K 254 connectors typically have a different stack height (often shorter) and may use tin-plated contacts instead of gold. TE Connectivity Micro-Match connectors have finer pitch (0.100" is available, but some variants use0.050") and different mechanical profiles. For a retrofit, you must: (1) verify that the DW-24-20-F-D-855's stack height does not interfere with your enclosure or adjacent components; (2) confirm that the 0.165" post length is compatible with existing receptacles (you may need new receptacles); (3) adjust PCB layout if row spacing or footprint geometry differs; (4) test electrical performance (signal integrity, impedance, crosstalk) if switching from tin-plated to gold-plated contacts. A direct drop-in replacement is unlikely; plan for PCB respin, new mating receptacles, and thorough functional testing before production.
• How does moisture sensitivity and PCB storage affect the DW-24-20-F-D-855 prior to assembly? The DW-24-20-F-D-855 has a Moisture Sensitivity Level (MSL) rating of Not Applicable, meaning it does not absorb moisture significantly and does not require special baking or dry-pack storage before assembly. This status simplifies procurement and inventory management compared to fine-pitch IC packages (which may require MSL Level 2 or higher, including vacuum-sealed bags withdesiccant and bake-out procedures). However, the PCB onto which you solder the DW-24-20-F-D-855 may have MSL requirements, particularly if it contains moisture-sensitive components. Store the DW-24-20-F-D-855 in a standard dry cabinet or room-temperature storage without special humidification control. When receiving boards pre-assembled with the DW-24-20-F-D-855, no special unpacking procedure is required. If your complete PCB assembly requires bake-out (due to other components), the DW-24-20-F-D-855 can withstand standard PCB bake-out temperatures (typically up to 120°C for 24-48 hours) without degradation.
• What signal integrity challenges should be considered when routing high-frequency signals through the DW-24-20-F-D-855? The DW-24-20-F-D-855 is a48-position, 2-row connector with 0.100" pitch, which affects signal integrity for high-frequency applications. At frequencies above 100 MHz, crosstalk between adjacent signal lines becomes significant due to the pitch and impedance mismatch at the connector interface. To minimize signal integrity issues: (1) use ground pins strategically—place at least one ground pin between every2-3 signal pins to reduce crosstalk and provide return paths; (2) maintain consistent impedance by controlling trace width and layer stackup near the DW-24-20-F-D-855 connection point; (3) minimize stub lengths by routing traces directly from the connector pins without unnecessary vias or trace loops; (4) use differential pairs for high-speed signals, ensuring equal-length routing and consistent spacing. If your application uses clock signals or serial data above 500 MHz, the DW-24-20-F-D-855 may introduce reflections and signal degradation unless carefully impedance-controlled. For such applications, consider whether higher-density, lower-pitch connector (0.050" or smaller) with better shielding or a dedicated high-speed connector (such as a LVDS or differential pair connector) would reduce signal integrity risk. Simulate the connector's impact using transmission-line models if clock speeds exceed 250 MHz.
• Is the DW-24-20-F-D-855 suitable for use in medical, aerospace, or military applications requiring specific certifications? The DW-24-20-F-D-855 is a commercial-grade connector without stated aerospace (AS2076 or MIL-DTL-26482), military (MIL-spec), or medical device certifications. If your application is for a medical device (regulated by FDA or other health authorities), aerospace (regulated by FAA or equivalent), or military use, using the DW-24-20-F-D-855 may not meet compliance or certification requirements. Medical device applications typically require component-level traceability, quality documentation, and validation testing per ISO 13485 or FDA guidance. Aerospace applications often mandate MIL-spec connectors or qualified equivalents with extensive reliability testing and documentation. Military applications similarly require MIL-spec or certified alternatives with rigorous testing protocols. If your primary application is commercial (consumer electronics, industrial automation, or standard computing), the DW-24-20-F-D-855's RoHS3 compliance and through-hole reliability are appropriate. For any safety-critical or highly regulated application, consult with the relevant certification body or your quality/compliance team before selecting the DW-24-20-F-D-855. Alternative qualified connectors may be required, which could impact cost and lead time.
• What tooling or assembly considerations apply when using the DW-24-20-F-D-855 in automated pick-and-place manufacturing? The DW-24-20-F-D-855 is a through-hole connector, which is typically not compatible with standard surface-mount automated pick-and-place equipment designed for SMD components. Assembly requires either manual insertion followed by wave soldering or selective soldering, or use of specialized through-hole insertion equipment (rare in modern high-volume production). For efficient assembly of the DW-24-20-F-D-855: (1) if production volume is low to medium, manual insertion with wave soldering is cost-effective; (2) if volume is high, consider investing in through-hole insertion equipment or partnering with an assembly provider that has such capability; (3) provide clear assembly fixtures to ensure correct orientation (the DW-24-20-F-D-855 is polarizable but not keyed, so board markings are essential); (4) account for insertion time in production scheduling—48 pins require careful alignment and insertion force; (5) pre-tin the PCB pads if using hand soldering to speed up the process and improve joint quality. Modern electronics manufacturing typically favors surface-mount connectors for automation efficiency. If your design cycle permits, evaluate whether a surface-mount 0.100" pitch connector alternative (from Samtec or competitors) would reduce assembly cost and increase throughput, accepting any necessary PCB layout adjustments.