940-99-028-24-000000 PLCC Socket Equivalent & Substitute Parts

Part Overview

The Mill-Max 940-99-028-24-000000 is a 28-position PLCC socket designed for through-hole mounting applications. This component features a closed frame design with tin-lead contact finish and is rated for -55°C to 125°C operation. The part is classified as obsolete, necessitating identification of active equivalent alternatives that maintain electrical and mechanical compatibility for new designs and production continuity.

Substiute Parts

940-99-028-24-000000

Mill-Max Manufacturing Corp.In Stock: 1110940-99-028-24-000000 Datasheet

Current PartRFQ

940-44-028-24-000000

Mill-Max Manufacturing Corp.In Stock: 2034940-44-028-24-000000 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

The 940-44-028-24-000000 qualifies as a direct substitute based on the following critical parameters:

• Identical pin count and grid configuration (28 positions, 4 x 7 layout)
• Matching mating and post pitch specifications (0.100" / 2.54mm)
• Identical mounting type (through hole) and termination method (solder)
• Identical contact materials (beryllium copper mating, brass alloy post)
• Identical housing material (PCT polyester)
• Matching operating temperature range (-55°C ~ 125°C)
• Identical current rating (1 A) and contact resistance (30mOhm)
• Identical termination post length (0.130" / 3.30mm)
• Identical flammability and compliance ratings (UL94 V-0, ROHS3, REACH Unaffected)

The primary difference is the contact finish specification: the substitute uses tin finish instead of tin-lead finish on mating contacts, with corresponding thickness adjustment (150.0µin vs. 100.0µin). The post contact finish remains tin in both parts with identical thickness (200.0µin).

Parameter Comparison

Engineering Selection Recommendations

The 940-44-028-24-000000 is the appropriate substitute for the obsolete 940-99-028-24-000000. Selection is based on the following factors:

The substitute maintains active product status, ensuring long-term availability and supply chain continuity. Both parts satisfy identical ROHS3 compliance and REACH unaffected requirements, supporting regulatory requirements for current manufacturing standards. The substitute's tin contact finish (without lead) aligns with modern lead-free manufacturing practices while maintaining electrical performance specifications identical to the original part.

The contact finish thickness increase on mating surfaces (150.0µin vs. 100.0µin) provides enhanced durability and wear resistance without affecting electrical or mechanical compatibility. All critical parameters—pin count, pitch, mounting type, temperature range, current rating, and contact resistance—remain unchanged, ensuring direct functional equivalence in circuit board designs.

Frequently Asked Questions (FAQ)

Q: Can the 940-44-028-24-000000 be used as a direct replacement for the 940-99-028-24-000000 in existing designs?

A: Yes. Both parts share identical electrical and mechanical specifications including pin count (28), pitch (0.100"), mounting type (through hole), operating temperature range (-55°C to 125°C), current rating (1 A), and contact resistance (30mOhm). The primary difference is the contact finish composition, which does not affect functional compatibility.

Q: What is the difference between tin-lead and tin contact finishes in these PLCC sockets?

A: The main part uses tin-lead finish while the substitute uses tin finish. Both finishes provide equivalent electrical performance and contact resistance. The tin finish in the substitute reflects current manufacturing standards and regulatory compliance with lead-free requirements. The increased thickness of the tin finish (150.0µin vs. 100.0µin on mating contacts) compensates for durability.

Q: Are there packaging differences between these two parts?

A: The main part packaging is not specified in available documentation. The substitute is supplied in tube packaging. Packaging format does not affect electrical or mechanical performance and is primarily a logistics consideration for procurement and assembly processes.

Q: Do both parts meet the same compliance standards?

A: Yes. Both the 940-99-028-24-000000 and 940-44-028-24-000000 are ROHS3 compliant, REACH unaffected, and rated UL94 V-0 for flammability. Both have moisture sensitivity level 1 (unlimited), indicating no special storage or handling requirements.

Q: Why is the original part classified as obsolete?

A: The 940-99-028-24-000000 is obsolete due to manufacturing discontinuation. The 940-44-028-24-000000 represents the active equivalent in the Mill-Max 940 series PLCC socket product line, providing continued availability for new designs and production requirements.