Introduction to Mill-Max Custom Capabilities

Since 1971, Mill-Max Manufacturing has been a trusted partner of OEMs for application-specific machined pin connector solutions. When design challenges arise during product development, an off-the-shelf connector may not always suffice. About half of the products we supply are custom, which makes us the go-to supplier for obscure, out-of-the-ordinary designs.

Why a Machined Connector

As circuit board real estate shrinks and component packages get smaller, the need for customization grows. The key factor for product longevity is connection reliability, and a machined connector is particularly suited for demanding or rugged applications where mechanical stability and a reliable electrical connection is crucial. See Delicate Circuits in Demanding Environments and Introduction to Precision Machined Technology.

Today's compact systems demand more functionality while limiting size, weight and cost. Mill-Max specializes in micro and miniature connectors that hold design integrity in challenging environments while keeping the smallest, lightest form possible. For the specific levers available, see The Path to Miniaturization and Zero-Profile Press-Fit Receptacles.

From Prototype to Production

Our full-house production capabilities transition from prototype parts to full production without delay. On-site machining, plating, assembly and packaging in North America, plus an in-house tool room, mean no reliance on outside sources and no barriers to development. Our US-based engineering team responds quickly, submits detailed proposals, and always aims at the most cost-effective solution. We will also recommend features worth designing in now in anticipation of a high-volume order later, for example features that facilitate packaging on tape and reel.

What We Can Customize

We can customize just about every aspect of our product offering, from the machined pin to the insulator. We review each design for manufacturing feasibility and provide a suitable solution within a competitive lead time, and our plating lines can finish your custom machined component with a selection of industry standard finishes.

Custom Discrete Pins, Receptacles and Spring-Loaded Pins

More than 200 high-speed turning machines on our premises produce custom pins, receptacles and spring-loaded pins to your exact specifications, at a low minimum order quantity of 1,000 pieces, whether you are modifying a standard part or creating one with all-new features.

Machined Laminate, the FR-4 Custom Connector

Where a connector is needed at prototype or low volume, we mill the insulator from laminate sheet rather than molding it, which avoids a costly mold tool up front and carries a minimum order quantity of just 50 pieces. Machined laminate and FR-4 custom connector describe the same capability: FR-4 is the laminate we use most often, with G-30 polyimide available for high-temperature work. Standard material thicknesses run from .010” to .500”. Many of our standard components incorporate a press-fit feature, which is what makes assembly into laminate practical and batch production quick. The same capability produces pin receptacle carriers for placing multiple parts in one action.

Injection-Molded Production Connectors

As volumes climb, we transition to a custom injection-molded insulator, which is more suitable and cost-effective for high-volume production.

Specialized Materials and Mix-and-Match Options

When your industry has stringent design requirements, we offer alternative materials that go beyond a COTS connector: high or low temperature, low force, outgassing, fine pitch, and ultra-low profile.

• Beryllium nickel contact clips in place of beryllium copper above 150°C. See High Temperature Beryllium Nickel Contacts.
• Stainless steel internal springs for elevated force, ruggedness and high temperature, or low-force springs to reduce mating force. See current-temperature derating curves.
• Insulator options for high-temperature or specific outgassing requirements, including FR-5, G-11 epoxy and G-30 polyimide.
• Specialized plating materials and non-standard plating thicknesses on any custom pin or receptacle.
• Non-magnetic materials and plating, where the nickel barrier plate is replaced with a thicker copper under plating.

The lists above draw on our standard spring and contact clip offerings, which cover most requirements. Where they do not, a custom spring can be produced roughly around 12 to 14 weeks. Custom contact clips are possible by special request, but the tooling involved often makes them cost prohibitive, so we will usually recommend a standard clip whose acceptance range suits the mating pin before going down that road. Ask us early and we will tell you which way your application points.

Mixing and matching also applies inside a single spring-loaded pin. A spring-loaded pin is built from a plunger, a body, a spring and an internal contact, and those components can often be recombined to reach a configuration we do not already offer as a standard part. Pairing a different plunger tip with an existing body, or the reverse, is usually the fastest route to a custom spring-loaded pin, because it draws on components we already produce rather than starting from new tooling. Tell us the mating surface, the working travel and the force you need, and we will tell you whether a recombination covers it.

We can also mix and match technologies within one connector: an SMT connector with thru-hole alignment pins for stability, spring-loaded pins of differing heights for first-mate last-break sequencing, or threaded inserts for fastening. Our in-house engineering team supports every stage from conceptualization through design, assembly, production and final delivery, and when form matters as much as function we will work with you on the appearance and source material specific to your needs.

Next sectionCustom Connector Manufacturing: how injection molding, machined laminate insulators, and additive manufacturing compare across volume, tooling, and lead time.