Seven considerations for connectors in circuit design

The smaller the connector, the more important it becomes.

The reason is simple: products are getting smaller.Smartphones, tablets, blood sugar detectors and countless other electronic devices are becoming more and more size – and compact – inside, leaving little room for connectors.This trend is also occurring in defence and aerospace sectors, such as satellites, guided missiles and avionics systems, where compactness requirements can only be met by “miniaturized” connectors.

As the demand for smaller connectors continues to grow, design engineers face a new set of challenges.They can no longer put connector design at the end of the project.Microconnectors require foresight.It requires designers to consider a variety of factors in advance, such as packaging, durability, current load capacity, and replaceable performance.

1Consider connectors early in the design process

“Engineers tend to focus too much on designing the whole system and leave connectors to the last stage of the design process.”"They thought the connector was simple, so they were able to put the relevant design on the back end,” said Mitch Storry, Director of engineering development at TE ConnecTIvity.Then they got stuck in their design.”

Storry has seen too many stories of designers rushing to design connectors late in the design process.In many cases, he told us, designers end up choosing non-standard connectors, which drives up costs and delays deliveries.

To avoid this problem, experts recommend thinking about the connectors you’ll be using early in your design, then making room for them and designing around them.

“No one is listening to you say, ‘First, decide what ConnecTIvity you need,’” said Stephen T. Morley, product development engineer at TE ConnecTIvity. “But if they do, it actually saves them a lot of time and hassle.”

2. Be aware of space limitations

Although micro plate-to-plate connectors are usually less than 1 mm thick, they are also commonly used in tightly packed applications.In order to solve potential packaging problems, the designer needs to consider the wiring on the PCB board and the additional wires attached to the connector.”Because the spacing is smaller, you have to make the lines and wires narrower.”"Says Mike Higashikawa, regional product manager at Molex.

Also, keep in mind that some connectors, such as flexible cable connectors, provide the option to flip forward and backward.When you’re designing a system, you need to think about these flips.For example, a connector that flips backwards might not be easily accessible if it has another component on the front and back.

Finally, designers also need to be aware that surface mount devices sometimes cannot handle smaller components.In some cases, they need new vacuum nozzles to solve these problems.

3. Find out the current load capacity

As the size of the connector decreases, the current load capacity of the connector decreases.Typically, microconnectors can handle currents between 200mA and 500mA, about half the rated current of larger plate-to-plate connectors.To compensate for low current capacity, the designer may need to increase the number of terminals.

4. Consider the stability of small/micro connections

“I need to suggest that, not only at the design stage, but also during the assembly process, to make sure that they are not damaged.”Morley of TE ConnecTIvity.

Morley, an expert in microconnector design for RF applications, recalls that half of the connectors he designed for military and space applications were destroyed during the testing phase.

Not taking the issue to heart first could drive up costs, he said.Damaged connectors need to be reconfigured, refurbished, and tagged.Even more expensive, on-site replaceable connectors might be needed, and such a change could extend the design time by another week or two.

“It’s important to always prioritize existing connectors,” Morley says. “If they’re not compatible with your design, consider designing your own, which can save you a lot of time.”

5Consider replaceable nature

If the product is enclosed on the outside, then you need connectors that can be replaced from the outside.Otherwise, you’ll need to do some welding work.

“The more you do it, the more skilled you become at things like welding, but the higher the risk of damage to the whole system,” Morley said.

6. Understand the functional requirements of the connector

Suppliers need customers to fully express their needs, or they may misunderstand their needs.This is especially important when you need to build custom connectors.

“It’s crucial to articulate exactly what a connector needs to be,” says Storry. “If it’s unclear or missing, we may miss key design requirements.”

Consider mechanical stress

Temperature, shock, and vibration all create stress between the interface and the circuit.Experts recommend that you choose connectors that avoid these forces.

“I’ve seen splintered solder joints on some PCB’s,” Morley said. “When the connector is firmly attached to the board or external structure, it has to withstand the force of impact and vibration, or it could crack.”

Morley recommended that engineers use interconnect systems to minimize the accumulated stress between mounting structures and connection points.”There are a number of vendors that offer such systems.”"Designers should pay close attention to this,” he said.

 

 


Post time: Nov-24-2020