The DNA of a Connector

The DNA of a Connector

Our last post introduced the fundamentals of what connectors—or Interconnect solutions—are. We discussed the three main applications: one-time use, high cycle life and permanent installation. In this post, we’ll be discussing what goes on inside of the connector. This discussion and the customization of what goes on inside the connector will help support the reality that a connector cannot be seen as an “off-the-shelf” component.

So, what is inside a connector?

Have you ever stopped to think; “What am I connecting this cable to?” when you insert a cable into a product. Simply put, the insides of a connector are made up of contacts and wires—mind you, extremely “simply put.”

The engineering that goes into an interconnect solution is vastly more complex than we may assume as we plug in our cellphones at the end of each day. Within that “simple” cord are numerous pieces that can vary from connector to connector—contact housing, the contacts themselves and any number of wire variations, shielding, etc.

Focusing specifically on the contacts that are critical to each connector, there are what’s referred to as “male”/static contacts and “female”/compliant contacts in each interconnect solution. There are three primary types of mating contacts:

  1. Pin and Socket
  2. Blade and Beam
  3. Pogo Pin and Pad

What are the Contact Mating Types?

  1. Pin and Socket
    • Pins and sockets are either machined or stamped.
      • – Machined — High quality, long life but high cost.
      • – Stamped — Reasonable quality and durability at a much lower cost.
  1. Blade and Beam
    • Typically, a simple, flat stamped “blade” for the fixed contact OR a simple, flexible stamped beam for the compliant contact.
    • Good performance vs. cost (when executed properly)
    • Tooling is extremely simple and parts are very economical
    • Easier and more cost effective to automate assembly
  2. Pogo Pin and Pad
    • A spring-loaded pin that is pressed and held against a flat mating pad
    • Contact integrity can be compromised due to lack of wiping action during mating (wiping cleans the surfaces)
    • A separate mechanism is necessary to hold against the separating force created by the pogo pin spring.

How do contacts connect to the wiring?

  1. Solder contacts:
    • Contacts are designed to have the wires soldered to the contacts. Requires soldering skills and time.
  2. Crimp contacts:
    • Wire is inserted into a hole or other aperture in the contact and the wire interface region of the contact is squeezed (deformed) tightly against the wire. This method makes for quick connections; good process controls are required to assure proper crimp quality. Requires crimp tooling (dies).
  3. Insulation Displacement Connector (IDC):
    • Contacts have a slot with sharp edges. Wires are pressed into the slot without the need to strip the insulation. The edges of the slot cut through the insulation as the wire is being pressed into the slot. The contact slot is sized to securely interface with the conductor (interference fit). Contact must be sized for a specific wire gauge. Works best with solid wire. Rapid connection of multiple conductors. Stripping time and controls are eliminated.

We’ve peeled back the covers a little bit and you can start to see the intricacies of a connector. But connectors, like onions, can look so simple from the outside but as you peel back layer-by-layer and look a little deeper the true complexity becomes more apparent. Continue on to learn more about what makes up the connector and, more specifically, the cabling on the interconnect.

 

How can ATL Technology help with your next connector or interconnect project?

ATL Technology in an interconnect solutions company, we specialize in design, development, and production of devices that are connector based. We succeed by incorporating our partners engineering teams with our engineering teams, their project management with ours, and so on.  We use our experience and expertise to benefit our partners by commercializing innovative devices that are accessing and treating previously untreated conditions in the human body.

The ABCs of Connectors

The ABCs of Connectors

We wanted to dedicate this next couple of weeks’ posts to discuss connectors/interconnect solutions, starting with the basics and working to share some of the innovations in the field of connectors, including what a medical device engineer should look for when selecting a connector supplier. Hope you enjoy!

It’s not too far-fetched to assume that this morning you woke up, got ready for your day and grabbed at least one mobile device before scurrying out the door. Imagine that as you jumped in your car or sat down on the train, to your astonishment, your device had failed to charge—despite being plugged in—due to a faulty power connection. That simple connection we think so little about has created a completely unnecessary headache.

On a daily basis, we take these connections—and so many more of equal and even greater importance— for granted, and don’t think about how critical these connection are until there’s a disconnect.

One industry where connectors or interconnect solutions have become increasingly significant is in the medical world. Devices that have historically been non-electric are evolving, advancing and connecting to power and data, the critical nature of these connections are such that they, literally, can be the difference between life and death. As the evolution and complexity of the medical device moves forward, the connector cannot be seen as an “off-the-shelf” component any longer.

 

So, what is a connector?

‘Connector’ is such a broad term. We use connectors every day when we charge our smartphone, tablet, laptop, or plug in our TV, coffee maker or hairdryer. But what should an engineer think of when discussing a connector or interconnect solution?

According to John Holloway, Primary Engineer at ATL Technology, “to start, you need to ask a few basic questions:

  • “How many times does it need to connect?
  • “How long will it be used once it connects?
  • “What contacts will we be using?
  • “How many conductors do we need?“

 

No one-size-fits-all connector solution

There are thousands of possible solutions to connect your devices. Whether you operate in a medical setting, in the tech sector or just plan to stay connected at home, there are three basic categories for connectors or interconnect solutions:

  • One Time Use (OTU)
  • High Cycle Life (HCL)
  • Permanent Installation (Connect it, Leave it Alone)

 

One-Time Use

Largely used within the medical industry to eliminate contamination, one-time use connectors are designed to be mated once and used for a procedure such as:

Even though OTU connectors are designated for single use, in practicality, they need to withstand at least 30 cycles with no degradation in performance. This makes it possible for testing at OEMs like ATL—as well as for end users—to connect and reconnect multiple times (to detangle cables or verify full insertion).

Low cost is a typical requirement of an OTU connector, and attributes are typically thin plating, with inexpensive alloys and plastics since fatigue is not a concern.

 

High Cycle Life

Similar to the use and abuse your mobile device’s power cord receives, high cycle life connectors are frequently mated and detached during a use. Some of the common connectors are:

  • USB, HDMI, small appliance power cords, docking bays, etc..
  • Applications are products like reusable instruments, portable device charging and data connections (think cell phones) and a host of others.

Typical attributes for HCL connectors are more costly contacts (Phosphor Bronze and Beryllium Copper) and heavier plating to support constant usage.

 

Permanent Installation

Permanent installation connectors are typically connected once and then left alone until service or repair of a device is needed.

Examples of permanent connections are automotive applications, internal equipment connections PCB edge connectors, etc.

Challenges can be wearing from vibration, fretting corrosion, and durability of plastics and seal materials, particularly in harsh environments.

A few of the typical attributes of permanent connectors are higher contact force, fatigue and creep resistant materials, higher-grade plastic materials and plating selections appropriate for the environment.