Glossary

Annealing

A heat treatment process that alters the physical and sometimes chemical properties of a material to increase its ductility and reduce its hardness, making it softer and more workable. It involves heating a material above its recrystallization temperature, maintaining a suitable temperature for a specific amount of time, and then cooling. Mill-Max brass pins and receptacles are often annealed to make them easier to crimp, rivet (swage) or bend.

Barb
Barb Example

Sometimes referred to as a fish-hook, a barb is a common press-fit feature machined on many pins, receptacles, and spring pins. This feature is used predominately to retain products in non-plated through holes such as ones in insulators or plastic housings. A barb retains a product by ”biting” into the sides of the mounting hole during assembly, generating an interference fit between both components. Barbs do not offer any anti-rotation properties, so a knurl retention feature is often used instead when this is a firm requirement.

Bi-furcated
Bi-Furcated Pins
Bi-Furcated Pins

A horizontal slotted feature intended for edge mounting. The location of the slot lends itself to being utilized in applications requiring parallel board mounting.

This feature is also machined with two flats, allowing the component to be partially press-fit into the board prior to soldering. Learn More

Blind Mate

Mating of one or more components where visibility is obstructed or limited.

Blind Mating Connection
Typical Blind Mating Connection

This process can lead to damage or breakage due to misalignment during mating. To mitigate this risk with pin + receptacle connections, receptacles with generous countersinks/lead-ins are used along with alignment pegs and/or shrouded housings to further guide the mating pin to the center of the receptacle. Spring loaded connections are better suited for blind mates due to the lack of insertion required. Furthermore, customers have used target pins with a concave face to help guide the plunger component of the spring pin towards the center of the target.

Body

Refers to the central section of a pin, receptacle, or spring pin. Typically machined out of a brass alloy material.

Bottom Entry Receptacle

Typically, Mill-Max receptacles are assembled into a PCB with the contact clip towards the top of the board, and the mating lead being driven from the top-down. In bottom entry receptacles, the clip is loaded into the bottom end of the shell (side opposite the shoulder). When this style of receptacle is assembled into the board, the lead must be inserted upwards from the bottom of the board. View Examples.

Bulging

A slight and uncontrolled deformation of the receptacle shell that might occur after a contact clip is inserted during the receptacle assembly process. Most commonly a result of the receptacle shell having a thin wall, which is due to the coaxial hole diameter and the outer diameter being comparable in value. Typically results in a .001”-.003” increase in the outer diameter of the receptacle shell located near the contact entrance. Can typically be averted by adding a shoulder to the receptacle shell or increasing the thickness of its walls.

Receptacle Bulging Example
Carrier/Transporter

An assembly consisting of an insulator with male dummy pins onto which discrete receptacles are loaded. This assembly is employed as a fixture during a soldering operation and is subsequently removed leaving a PC board populated with individual receptacles. Carriers that load male pins are also available for special applications as custom/made to order solutions. Learn More.

Clip (Contact)
Contact Clip

The multi-finger spring insert component of a receptacle assembly. Its primary function is to generate the electrical and mechanical connection between a female receptacle and its mating male pin or lead. This is achieved by means of the fingers or tines of the component, which grip the pin/lead upon proper insertion and allow for multiple insertions.

Contact Clips are stamped and formed from Beryllium Copper or Beryllium Nickel for high temp applications. Learn More.

Closed Bottom
Closed Bottom Receptacles

A type of receptacle whose body is closed or sealed on the side opposite the contact clip. This allows the mating pin or lead inserted to “bottom out”, meaning that it is inserted to the point where it is contacting the bottom surface. While this has no bearing on the performance of the product, “bottoming out” does provide the user a simple method of determining whether the receptacle is completely capturing the mating lead. A closed bottom part also eliminates the concern of solder wicking up the bottom of the part during soldering procedures such as wave or reflow. View Examples.

Compliancy

A contact clip's ability to accept multiple insertions and extractions of a wide range of pin shapes and sizes while retaining its original configuration. The acceptance range of the contact will typically be altered after inserting the maximum permissible pin. For example: the #34 contact has an initial operating range from .032" to .046" diameter pins and a compliancy of .010”. After insertion of a .046" pin, the contact is sized, and the minimum pin acceptance becomes .046" - .010" = .036". Thus, the new operating range becomes .036" to .046". The compliancy rating advertised for each of our contacts can be found on the General Contact Information page of our Catalog.

Compliant Press Fit

Method of mounting an interconnect component to a PC board where a drilled and slotted receptacle or pin feature is pressed into a plated through hole without damaging the hole.

Constant Usage Temperature (CUT)

Constant Usage Temperature is a measure of the maximum temperature that a material may be exposed to for long periods of time, 1000-1500 hrs., before degradation of its electrical and mechanical properties occurs.

Contact (and Contact Clip)
Contact Clip

The multi-finger spring insert component of a receptacle assembly. Its primary function is to generate the electrical and mechanical connection between a female receptacle and its mating male pin or lead. This is achieved by means of the fingers or tines of the component, which grip the pin/lead upon proper insertion and allow for multiple insertions.

Contact Clips are stamped and formed from Beryllium Copper or Beryllium Nickel for high temp applications. Learn More.

Contact Rating

Current carrying capability of a contact measured in amperes with respect to temperature rise above ambient.

Contact Resistance

A measure of how difficult it is for current to travel/pass through an electrical interface (may consist of components such as pin + receptacle and/or spring pin + target connector). A higher contact resistance is undesirable because the connection would be more inclined to resist electrical flow. Measured in ohms, this characteristic is impacted by both mating component’s geometry, plating, contact area and normal force. The actual interface typically consists of a contact area much smaller than what is seen by the naked eye, and results in a resistance value that is independent of the standalone resistance for each material in the mated set. An observable voltage drop across the connection occurs due to this resistance.

Contact Sizing
A value-added process that can be provided to discrete receptacles or socket connectors, typically to yield lower insertion/extraction forces. Prior to the parts being received by the customer, a pin lead with a diameter on the higher end of the contact clip’s acceptance range will undergo one mating cycle with the product. This process slightly pushes open the fingers of the clip, resulting in a looser fit-up with the mating lead upon subsequent cycles.
Coplanarity

Refers to the measurement of multiple points and their distance from a respective plane. This is particularly useful for surface mount parts to determine the maximum amount of difference in the height of the surfaces that need to be soldered.

Crimp Termination
crimp termination

A feature provided on certain pins, receptacles, and spring pins that allows for solderless wire termination by deforming the outer diameter of the product. The crimp parts will have a barrel on one end with a blind coaxial hole drilled into it, creating a thin wall which allows the material to be pinched or deformed. These features can accept a range of wire gauges while ensuring proper fit up for greater versatility. After a properly sized wire is inserted into the feature, the retention deformation is generated by use of a crimp tool and positioner. Validation of the retention force between the wire and the product can be evaluated by methods such as a pull test. Learn More

For more information view the following video, How to Crimp Contacts, By Daniels Manufacturing Corporation.

Current Rating

Current carrying capability of a product measured in amperes with respect to a specific temperature rise. For Mill-Max products, the current rating has been specified with a conservative 10°C temperature rise over ambient. The current rating advertised for a product can be found on the specific product’s webpage on our website. Please note that this performance characteristic is not specified for our solid male pins and male pin headers. As these products are composed of solid brass, one could theoretically put through as much current as desired with the only detrimental effect being heat generation.

Cycle

One complete mating sequence between two interconnect components. A cycle between a pin and receptacle combination refers to one full insertion and extraction of the pin into the contact clip of the receptacle.

Pin-Receptacle Cycle
One Pin/Receptacle Cycle

A cycle between a spring pin and target pin/pad combination refers to one compression of the plunger onto a target, typically to half-stroke, followed by a return to the uncompressed state

One Spring-Loaded Compression/Cycle
One Spring-Loaded Compression/Cycle
Device under Test (DUT)

Device or part being tested

Discrete

Referring to an individual pin, receptacle, or spring pin component rather than an assembled connector. A connector assembly is created by loading one or more discrete components into an insulated housing. Discrete components can be better suited for inconsistent and non-standard footprints, or applications where a housing would interfere with the neighboring or mating components.

Double Action

A spring pin that is manufactured with two plunger components, allowing for actuation on both sides of the product. These plungers share the same internal spring, so the travel distance is cumulative between both components. This type of product is an appealing solution for applications that require either a temporary or permanent connection between two parallel boards or devices without the use of solder. View examples.

Double Tail (Header) Pin

A male pin that has been machined with tails on both ends. The most common usage for this style product is for one tail to be solder mounted into a through hole on a PCB, while the other is used as a lead for mating into a female interconnect component such as a receptacle or socket. However, the product can also be utilized to generate an electrical connection by solder mounting it into through holes on two separate PCBs or by mating it between two female receptacles or socket components. This style product is often designed with a press-fit retention feature, allowing for assembly into an insulated housing to form a male header. The tails can either be identical on both ends or have differences in their diameters and lengths, allowing for further versatility. View Examples

Dual Entry Receptacle
Dual Entry Receptacle

A receptacle containing contact clips at both openings or containing an individual contact clip that is suitable for either top or bottom entry. Allows for more versatile use when compared to single entry female receptacle products. View Examples

Durability

A product’s anticipated life expectancy. Actual life is derived from the application along with the application conditions, temperature/cleanliness of the environment, and mating pin specifications.

Early Engagement

A contact clip designed to form a strong connection with a mating lead/pin without needing to pass the full length of the contact clip. Useful in applications where the mating lead is short in length. View Examples

Early Engagement Receptacle
Electro-Vibratory Plating
An electroplating system where the parts are processed in a vibrating basket which ensures uniform plating thickness and avoids damage to delicate parts.
Electroless Plating
Plating activation with the use of acid or solutions rather than means of an electric current to form a deposit.
Electromechanical

To relate to or involve an electrically operated mechanical device

Electroplating

One of the most important processes in the manufacturing of electronic parts and components is electroplating, which involves the application of a metal coating via electrodeposition. This is done for a number of reasons such as improving corrosion resistance, enhancing electrical conductivity, increasing the solderability of the substrate and protecting against wear.

Electrostatic Discharge (ESD)

The momentary electric current that flows between two objects that may cause damage to electronic equipment.

End Stackable

The ability for connectors to be mounted end to end while maintaining grid or spacing.

Epoxy

A type of glass filled material used to fabricate insulated housings, typically for lower volume production runs or rapid prototyping. Classified as a thermoset, the woven fibers of these types of materials enable them to withstand high temperatures (such as ones required for soldering) without being damaged. These materials are often provided in large rectangular sheets, suitable for machining on a high-speed drill/router, the same way printed circuit boards are fabricated. Epoxy housing are most commonly machined out of FR-4, but G-30 can also be utilized for higher temperature applications. Learn More.

Extraction Force

Sometimes known as the withdrawal force, this is the force required to remove a mating lead or pin from a contact clip. The value of this force is primarily driven by factors such as the specific contact clip selected, the base material of the contact clip, and the shape and diameter of the mating lead. The extraction force is also typically lesser in magnitude when compared to the same contact clip’s insertion force. Graphs illustrating the extraction forces for each contact clip can be found online or on the Receptacle Contact Data catalog pages.

Fibre Plug / OFP® Solder Barrier
OFP® Solder Barrier Receptacles

An organic paper plug used to create a solder barrier in open bottom receptacles. Designed to help prevent solder from wicking up the barrel of the receptacle during a reflow soldering operation. Once soldering is complete, the mating lead knocks the plug out of the receptacle upon insertion and the plug can be discarded. Learn More.

 

 

Flange (Shoulder)

An external rib or lip machined on most pin, receptacle, and spring pin components that is typically the largest external diameter. Most often located on one end of the part but can also be found near the center in certain designs. Its primary function is to assist in board assembly by orienting the product in the mounting hole and providing added support during solder or press-fit mounting. In spring pin and receptacle products, this feature also plays a pivotal role in the assembly of the component.

Flash (Plating)

A very thin layer of plating, usually less than 10 micro inches in thickness. Switching to flash plating from a thicker plating option is a common way to drive down the cost of a component, possibly at the expense of durability. This makes flash plating better suited for applications with benign environments that will not see aggressive handling or in ones where gold embrittlement is of concern.

Flatness

Sometimes used in place of coplanarity, flatness refers to the amount of variation of a plane or surface.

Floating Contact
Floating Contact Illustration

Refers to connectors that contain pins or receptacles designed to move up and down freely in an insulator, rather than being retained in place by a press-fit feature. This additional “play” allows the connector to compensate for unevenly dispensed solder paste, mating misalignment and other errors known to increase the amount of stress applied to the connector, PCB and/or solder joints. View Examples.

Free Machining Alloy

An alloy which is easy to machine, e.g. brass alloy 360.

Fretting

A form of wear that often leads to or increases the likelihood of corrosion. This wear is often caused by the repeated cyclical rubbing between two surfaces in which one is under a load. In pin & receptacle connections, this wear is often generated between the internal contact clip and the surface of the mating pin. In spring loaded connections, this wear is generated between the plunger of the spring pin and the mating surface or target. Over time, this wear results in the removal of material from one or both mating surfaces, resulting in the appearance of black spots, marks, lines or patches depending on the specific mode of fretting wear. As more debris is accumulated, the wear process by abrasion is accelerated which can then accelerate oxidation as more of the protective layer is removed.

Gas Tight Connection

An electrical connection of sufficient pressure to prevent the intrusion of a corrosive atmosphere into the contact area.

Gold Plating

Gold is commonly used in the plating of many different electronic components. Gold offers low and stable contact resistance and superior protection against corrosion. 

Nickel is often used to provide an underlying coating when using gold to plate electronics. Nickel acts as an extra corrosion inhibitor by preventing rust from penetrating pores in the surface. Nickel also prevents the diffusion of other metals into the gold surface such as zinc or copper. What's more, nickel can increase the durability of the gold-plated surface.

Mill-Max offers most of its products in standard platings ranging from 5 to 30 µin of gold over nickel. Since plating operations are conducted in house other thicknesses are available on request. 

Gull Wing
Gull Wing DIP Socket

A SMT termination style that is commonly utilized in Mill-Max connectors. A gull wing termination is characterized by the solder tails of the populated pins or receptacles being bent outward, resembling a gull. These bent tails are surface mounted to the board via rectangular solder pads specified prior to soldering. This termination style results in increased solder joint strength and permits easy visual inspection of said joints. Mill-Max offers gull wing SMT termination options in both male and female interconnect packages, including DIPs and single & double row SIPs. Learn More.

Heat Deflection Temperature (HDT)

An industry recognized test for comparing the short term effects of high temperature on plastics.

Heat Treating

The process of using specific heating and cooling cycles to alter the mechanical properties of an alloy. Generally, heat treating can harden or soften a metal depending on the material, the parameters used and the desired physical property.

Hex Press-Fit
Example of a Hex Press-Fit

A hexagonal retention feature machined on certain pins and receptacles intended to retain the product into a plated through-hole without the use of solder. While the retention feature is most often hexagonal in design, polygonal features such as square or pentagon shapes are also used. This style press-fit is also beneficial by reducing damage to the through hole during insertion, compared to press-fit features suited for non-plated through holes such as knurls or barbs. View Examples.

High Speed Turning

See Precision-Machined.

Injection Molding

A method of molding plastics by first heating granular plastic to its molten state and injecting it into the mold cavity where the plastic solidifies and is then ejected from the cavity.

Insertion Force

The force required to insert a mating pin or lead into a contact clip. The value of this force is primarily driven by factors such as the specific contact clip selected, the base material of the contact clip, and the shape and diameter of the mating lead. The force of the initial insertion will typically yield the greatest amount of force, as the mating lead is opening the fingers/tines of the contact for the first time. The insertion force is also typically greater in magnitude when compared to the same contact’s extraction force. Graphs illustrating the extraction forces for each contact clip can be found online or on the Receptacle Contact Data catalog pages.

Interconnect

Means of connection that supplies an electrical connection between the cells.

IP Rating
Measurement of how well a piece of equipment or device can resist penetration of water, chemicals, dust and other fluids or debris. Sometimes known as the water resilience or level of ingress protection a product has.
Knurl
Example of a Knurl

An array of vertical serrations machined around a diameter of an interconnect pin or receptacle, providing a retention feature for press-fitting into an unplated mounting hole in a PC board or insulator. This feature prevents the pin from rotating within the mounting hole, which may be beneficial in applications where alignment is critical. View Examples.

Land/Pad

Typically, gold plated, round or flat surface, commonly used for mating purposes also known as a target.

LCP (Liquid Crystal Polymer)

Classified as a thermoplastic, LCP is a hard, rigid material which exhibits outstanding strength at high temperatures and exceptional strength and toughness in its thin walls. Applications: LCP is used as an insulator material for tight grid (.050", 2mm) connectors and extremely high temperature requirements.

LIF
Light Insertion Force
Machined

Manufacturing process whereby a rapidly turning solid metal rod is cut to precise tolerances. Also known as Screw-Machined or Precision Machined.

Mated Height
The assembled height of a male and female interconnect once engaged/mated.
Mating Pin

The pin used to interconnect two electronic devices by inserting it into the contact. Critical features are diameter, length, and shape (but not limited to.)

Max Stroke

The maximum possible distance the plunger of a spring pin can be compressed or actuated. It is primarily dependent on the characteristics of the internal spring and the construction of the specific spring pin. While it is possible to compress a spring pin to this particular distance, it is not recommended in applications that are looking to maximize both mechanical and electrical performance. However, applications that require minimal cycling may see electrical benefits when compressing the spring pin to its maximum stroke or close to it.

Spring Pin Strokes
Mid-Stroke

Considered the optimal stroke distance for all spring-loaded products. The Mid-Stroke will be (~) approximately half of the Max Stroke.

Misalignment

Defined as incorrect or poor alignment between mating components, features, or products within an interconnect system. It can occur in pin & receptacle connections when the mating pin inserted at an aggressive angle. It can also occur in spring-loaded connections by exposing the plunger of the spring pin to a lateral or side load. While a small amount of misalignment is to be expected and acceptable during a mated connection, an excessive amount can cause significant damage to the mating components. This damage may present itself in the form of reduced component performance and/or premature failure.

Pin/Receptacle Misalignment
Pin/Receptacle Misalignment
Spring-Pin Misalignment
Spring-Pin Misalignment
Mounting Hole Size

Size call out for the mounting holes.

Nail Head Pins
Nail Head Pins

A versatile male pin machined in the shape of a nail. Can be used for a multitude of purposes including board stacking, board to component connections, mating surfaces for spring loaded products, and many more. The main draw of this style of pin is its ability to provide a thru connection while having a low-profile head/largest diameter. View Examples

Nylon 46

Classified as a thermoplastic, Nylon 46 offers superior heat resistance, good electrical properties and excellent toughness in its thin walls, which are desirable characteristics for connector insulators. Its superior strength in thin walls enables the press-fitting of pins in close proximity to each other without cracking or warping the material, making it ideal for molding 1mm, 2mm and .050" grid insulators. Nylon 46 is suitable for high temperature applications including vapor phase, infra-red reflow and wave soldering operations.

OFP® Solder Barrier/Fibre Plug

An organic paper plug used to create a solder barrier in Open Bottom receptacles. Once soldering is complete, the mating lead knocks the plug out.

Open Bottom
Open Bottom Receptacle

A receptacle shell which has a full length internal coaxial hole, making the component hollow or straw-like. This design allows the mating lead or pin to protrude through the receptacle upon insertion. This is especially appealing for pins or leads that are quite lengthy or those who need to be trimmed as a post insertion procedure. View Examples.

Open Frame
Open Frame Insulator

A type of DIP insulated housing where there are one or more open/hollow sections in the center of the component, similar to that of a cut-out window. These features help minimize the amount of board space the connector takes up by allowing for additional components to be mounted to the board within these open sections. They can also aid in the inspection of the solder joints by providing further visibility when compared to a closed frame product. View Examples

Operating Temperature
The operating temperature is the temperature at which an electrical or mechanical device operates. The device will operate effectively within a specified temperature range which varies based on the device function and application context, and ranges from the minimum operating temperature to the maximum operating temperature (or peak operating temperature). Outside this range of safe operating temperatures the device may fail.
Over Compression

The condition by which a spring pin or spring-loaded connector is actuated past its specified maximum stroke distance. Spring deformation can occur, causing it to bind and remain set/stuck in the same position without returning to its original uncompressed state. When designing mated sets of spring-loaded products, tolerances should be accounted for to avoid over compression – using between 25% and 75% of the spring pin’s maximum stroke is ideal.

Passive Device or Component

An electronic connector that consumes electrical energy, but does not produce electrical energy. Passive devices are not susceptible to significant ESD damage.

PCB
A printed circuit board (PCB) mechanically supports and electrically connects electronic components or electrical components using conductive tracks, pads and other features etched from one or more sheet layers of copper laminated onto and/or between sheet layers of a non-conductive substrate. Components are generally soldered onto the PCB to both electrically connect and mechanically fasten them to it.
PCB Connectors

PCB Connectors can be referred to as PCB Interconnects or Rectangular Connectors. Specific terms are also used for the two sides of the connection. Male PCB Connectors are often referred to as Pin Headers, as they are simply rows of pins. Female PCB Connectors can be called Sockets, Receptacles, or Socket Headers.

PCT (Polycyclohexane Terephthalate)

Thermoplastic polyester is rated for higher temperatures. PCT is a standard material on DIP and SIP insulators for higher temperature operations. All PGA and surface mount products are molded from PCT and are suitable for infra-red, vapor phase and wave soldering.

Pick & Place

An assembly process by which automated equipment is used to place a broad range of electronic components onto a printed circuit board quickly and precisely. A pick & place machine accepts tape & reel packaged parts, which are extracted individually from their tape pocket by a robotic arm fitted with a nozzle, and mounted in the desired location on the PCB. Parts may be assembled with a pick & place clip, typically removable, which provides a flat top surface for improved handling. Learn More

Pick & Place Cap/Clip

A removable molded plastic cap or clip component provided on certain products packaged on tape and reel. The primary function of this component is to aid in the removal of the part from the carrier tape. It provides a larger surface area for handling and keeps the part centered in the pocket. This component is typically left on the product during the soldering portion of the board assembly procedure, but it is removed shortly after the installation is completed. View Examples

Pick and Place Caps For Tape and Reel
Plated Through-Hole (PTH)
A hole in a printed circuit board which has metallic walls connected to conductors on the surface or inside the board, in which the component lead is inserted and soldered.
Plating

A process in which metals (e.g. gold, tin-lead, nickel, silver) are electrically deposited onto a base metal in very thin and precise thicknesses.

Plunger

An active driving component, typically driven by a spring.

Power Spring-Loaded Pin

Mill-Max spring pins that offer a higher current rating and larger overall diameters when compared to our typical spring pin products. The added size and robustness make them ideal for applications that require a more rugged interconnect solution, such as ones with rough or punishing environments. Power spring pins are offered discrete in through-hole solder tail, surface mount, solder cup and crimp mounting styles, as well as in assembled connectors with rugged insulator housings. View Examples

Precision-Machined (Screw-Machined)

A manufacturing process whereby a rapidly turning solid metal rod is cut to precise tolerances by means of a high-speed swiss screw machine. This process allows for the development of machined pins with features that are held to great precision and accuracy, sometimes sporting machining tolerances of less than .001 of an inch. Learn More

Press-Fit

To use a designed (Barb, Hex, Square, or Knurl) feature to secure a pin, receptacle, or spring-loaded pin into a board, housing, or Plated Through-Hole (PTH).

Profile

With electrical components, the profile typically refers to height of the part above the board after assembly. PCB assemblies can require multiple stacked boards set at fixed distances on top of each other, which may limit what the height of an individual component or a set of mated components can be. Designs which require flush components without any protrusion on top of the board are referred to as zero profile applications. Ultra-low and low-profile applications attempt to conserve board height by using short, compact components with minimal mated height. Mid and high-profile applications exist as well, with “board stacking” header/socket mates being used to actually add more height by “filling in the gaps” between two boards with a mated set.

Receptacle

Sometimes referred to as PCB sockets, micro-plugs or connector jacks, machined pin receptacles are a two-piece female construction consisting of an outer shell and inner spring contact (clip). Receptacles are designed for multiple mating/de-mating cycles with a male pin or lead to facilitate an electrical connection. They are used discretely in a PC Board or arrayed in plastic housings as connector assemblies and can help make devices pluggable for easy repair and/or replacement. Learn More

Screw-Machined (Precision-Machined)

A manufacturing process whereby a rapidly turning solid metal rod is cut to precise tolerances by means of a high-speed swiss screw machine. This process allows for the development of machined pins with features that are held to great precision and accuracy, sometimes sporting machining tolerances of less than .001 of an inch. Learn More

Secondary Machining

A process in which holes, slots, flats, squares or other special features may be machined onto a pin or receptacle after the basic shape of the part has been turned on a high speed lathe.

Selectively Loaded/Populated

A connector design where the insulated housing isn’t uniformly populated with the same exact pin, receptacle, or spring pin in all available mounting hole positions. Rather, the arrangement may include empty, unpopulated positions or switch between using different components in the same assembly. One example of a selectively loaded connector could be a nine-position strip header loaded in only five positions. This assembly would be considered selectively loaded as it alternates between a pin position and an empty unloaded position. Another example could be a four-position strip socket which uses one type of receptacle for the first two positions, and a different receptacle for the last two positions.

Selectively Loaded Connector

While selectively loaded connectors are often provided as custom oriented solutions, Mill-Max does offer a few standard series in this particular style. View Examples 

Shell
A precision screw machined component, typically cylindrical and manufactured out of a brass alloy. Its primary function is to serve as a housing for the contact clip in female interconnect assemblies such as receptacles or sockets. A prevalent feature in receptacle shells is a drilled hole that is machined through the center; the majority are also designed with a flange used to aid in both receptacle and board assembly. In addition, some shells are designed with unique features for press-fitting, solder tails for through-hole mounting, and various types of wire termination features to allow for use in a wide range of applications.
Shell

A precision screw machined component, typically cylindrical and manufactured out of a brass alloy. Its primary function is to serve as a housing for the contact clip in female interconnect assemblies such as receptacles or sockets. A prevalent feature in receptacle shells is a drilled hole that is machined through the center; the majority are also designed with a flange used to aid in both receptacle and board assembly. In addition, some shells are designed with unique features for press-fitting, solder tails for through-hole mounting, and various types of wire termination features to allow for use in a wide range of applications.

Shoulder (Flange)

An external rib or lip machined on most pin, receptacle, and spring pin components that is typically the largest external diameter. Most often located on one end of the part but can also be found near the center in certain designs. Its primary function is to assist in board assembly by orienting the product in the mounting hole and providing added support during solder or press-fit mounting. In spring pin and receptacle products, this feature also plays a pivotal role in the assembly of the component.

Shrink DIP (SPDIP)
SPDIP Sockets

A DIP connector provided on .070" pitch/centers instead of the more common .100” spacing. These packages are useful in applications that require a DIP style connection but cannot afford the board space required for a standard .100” DIP. Learn More

Side Load

A horizontal or lateral force that is applied to a part or component in an application.

Skiving

The removal of a thin amount of plating when pins or contacts are press fit. For example, soft platings may yield some amount of skiving upon press fitting into an insulator or board. Skiving may also appear under a contact clip pressed into a receptacle shell.

Solder Tail

For Through-Hole requirements, this tail feature serves as a stable anchor for either soldering or mounting.

Soldercup
Soldercup Application

A type of wire termination feature that consists of a drilled hole at the end of a pin, receptacle, or spring pin with a radius cutout. This cup feature eases the insertion of the wire and provides better visibility while soldering. Wires as large as 14AWG to as small as 26AWG, and potentially smaller, can be assembled quickly and efficiently. View Examples

Spring Force

The amount of force required to compress a plunger to a specified distance.

Spring Force Constant

(Conducted on a MM # 0900-X Spring Pin Connector)

k = Force (60) - Preload (25)/Travel (.0275) = 1272.73 g/in.

Preload = 25 g
Force = 60 g
Travel = .0275"

Spring Rate

The spring rate of a spring will be determined by spring material, diameter of the material, and number of coils per the spring length.

Standoff / Mounting (Alignment) Peg
Socket with Standoffs

A plastic protrusion at the bottom of certain connectors used to raise the product off the PC board to aid in solder fillet formation, board inspection, flux removal, alignment and cleaning.

View Example

 

 

Stroke/Travel

The specified distance by which the plunger of a spring pin compresses when being cycled. Each spring pin is rated for a maximum stroke distance, starting from the product at its initial height in a completely uncompressed state. As a general recommendation, between 25% and 75% of the max. stroke should be used for optimal electrical and mechanical performance. Excessive compression of the plunger past the max. stroke value (over-compression) can jeopardize performance and cause premature failures. Learn More

Swage Mount
Swage Application

A method of mechanically fastening pin terminals to a circuit board, similar in style to riveting. It is commonly used with solder terminals and printed circuit board pins for low to medium volume applications. The swaging technique captures the board between the flared or swaged material and the shoulder of the pin, fastening the pin to the board.

While not formally required, a soldering procedure can be conducted after the swaging process to improve the mechanical and electrical reliability of the connection. Learn More

Tape & Reel

Component packaging suited for use with automated pick & place equipment. Parts are housed on a continuous tape strip, each one placed inside a formed pocket based on the part’s specific design and dimensions. Adjacent pockets are spaced at a consistent distance, referred to as the pocket pitch. The cavities are further secured by a cover tape placed over the top. The entire carrier tape strip is wound up onto a reel for easy loading into a pick & place machine. Learn More

Target

Typically, gold plated, round or flat surface, commonly used for mating purposes also known as a land or pad.

Thermal Coefficient of Expansion (TCE)

Expansion of material caused by an increase in temperature.

Thermoplastics

Plastic polymers that soften when they are heated and solidify again as they are cooled, allowing for molding/shaping operations such as injection molding. Due to their unique chemical properties, thermoplastic materials can be remolded and recycled without negatively affecting the material’s physical properties. All of Mill-Max’s standard connectors that are assembled with molded plastic insulators/housings would be considered thermoplastics.

Thermoset

Plastic polymers that can only be heated and molded once. This makes them ideal for high temperature applications, as excessive and/or prolonged heat will not change or deform the material. Mill-Max utilizes thermoset materials such as FR-4 (G10) in custom machined plastic housings.

Threading

The defining feature of screws, nuts, and bolts which consist of grooved helical ridges wrapped around a cylinder. Threads are used to mount components onto a board or housing without the use of solder or an adhesive, or for fastening two components together for added mechanical rigidity. A threaded connection requires one component to be machined with exterior threads, allowing it to be torqued into a mating component with corresponding interior threads. The features that support threaded mounting can be found on both discrete and connector-based solutions. View Examples

Top Plate

Final surface plating over base metal and underplating.

Underplate

The plating layer applied to a part before the top plate or surface coating. This layer is typically composed of either nickel or copper, but other materials can be used as well. The underplate contributes to the performance of the total coating by improving corrosion resistance, wear resistance, and solderability, and by also limiting the potential diffusion of base metal elements into the top plate such as zinc migration.

Uniform Orientation/Alignment

In a connector featuring multiple positions of a solder cup pin, receptacle, or spring pin, uniform orientation specifies that each individual cup in a row is aligned toward the same direction. This allows for a simpler, neater soldering process since each row of wires can be assembled from the same side of the connector in an orderly manner.

Alignment Examples
Universal Series Bus (USB) Connector

A common type of interface or connector that allows devices to communicate with a host controller such as a personal computer, for data, signal exchange or charging. Examples of peripheral devices typically connected by USB include external hard drives, mice, keyboards, printers, scanners, cameras and other media devices. Mill-Max offers a wide array of USB sockets designed for both SMT and hybrid style mounting. View Examples

Wire Crimp

Please see Wire Termination

Wire Termination

Typically involves wire insertion, crimping or soldering into the vacant coaxial hole located on the pin/receptacle.

Withdrawal Force

See " Extraction Force"

Wrapost (Terminal or Receptacle)

The length of square cross section of certain pins and receptacles which is used for making electrical connections via wire wrapping. Wire wrapping is a process in which wire is wrapped around the post to form a gas-tight connection without soldering.

ZIF
Zero Insertion Force
Zinc Migration

For a brass part plated with tin or gold, the migration of zinc from brass to the surface of the plating. This becomes zinc oxide and renders the part unsolderable. Zinc migration is prevented by using a copper or nickel underplate as a barrier.

Last Updated: 03/19/2019 05:30 PM