The reason is simple: the product is getting smaller. Now smart phones, tablet PCs, blood glucose detectors and other electronic equipment on the size of the increasingly stringent requirements, the internal more and more close, so leave the connector space is not much. This trend also appears in the field of defense and aerospace, such as in satellites, guided missiles and avionics systems, where compactness requires only "miniature" connectors to be met.
The demand for smaller connectors is on the rise and design engineers face a new set of challenges. They can no longer put the connector design into the final stage of the project to complete. Miniature connectors require foresight. It requires designers to anticipate a variety of factors such as packaging, durability, current load capacity, and replaceability.
The designer should consider the ease of replacement, especially in a closed housing. Molex VITA 67 is an easy to replace the miniature connector.
The following are some of the design recommendations from the micro-connector supplier. These recommendations not only from the connector design experts, but also the painful experience of the designer summary, it is worth the designer's reference.
1, consider the connector early in the design
"Engineers are often too focused on designing the overall system and putting the connector in the final stages of design," said Mitch Storry, director of product development engineering at TE Connectivity. "They think the connectors are simple, so they can The design was put into the final stage, and then they were stuck by their own design.
Storry has seen too many designers in the final stages of the design before the design of the connector in a hurry. He tells us that in many cases, the designer finally had to choose non-standard connectors to complete the design, which not only pulled up the cost, but also delayed the delivery time.
In order to avoid such problems, the experts suggested that in the early design should consider the connector you will use, and then reserved for their design space, the design also around its start.
"Nobody's reason to hear you say 'first, decide what connector you need,'" says Stephen T. Morley, product development engineer at TE Connectivity. "But if they really do that, they can save them a lot of time and less A lot of trouble. "
2. Understand the limits of space
Although miniature board-to-board connectors are typically less than 1 mm in thickness, they are also commonly used in packaged applications. In order to solve potential packaging problems, designers need to consider the PCB board alignment, and connected to the connector on the additional wire. "Because the pitch is smaller, you have to make the alignment and wire more narrow."
Also, keep in mind that some connectors (such as flexible cable connectors) provide the option to flip forward and backward. When designing the system, you need to consider these rollover methods. For example, if the back flip of the connector if there is another component on the back, it may be very easy to access.
Finally, the designer also needs to pay attention to the surface mount device sometimes can not 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 drops, the current load capacity of the connector decreases. In general, the miniature connector can handle a current between 200mA and 500mA, which is almost half the board-to-board connector rated current. In order to compensate for the problems associated with lower current carrying capacity, the designer may need to increase the number of terminals.
4. Consider the stability of small / miniature connections
"I need to suggest this, not only in the design phase, but also in the assembly process, to ensure that they are not damaged." TE Connectivity Morley said.
Morley is a micro-connector design specialist in RF applications, recalling that half of the connectors in the military and space applications he designed were destroyed during the testing phase.
If you do not put the problem first in mind, it may push up the cost, he said. Damaged connectors need to be reconfigured, refurbished and marked. And may even require more expensive, field replaceable connectors to replace, and such changes may allow the design time to extend for another one to two weeks.
"It should be noted that always have to give priority to existing connectors, and if these connectors are not compatible with your design, and then consider their own design, this will save you a lot of time."
5. Consider easy replacement
If the appearance of the product is closed, then you need to be able to replace the connector from the outside. Otherwise, you need to do some welding work.
"The more you do, the more proficient you are on welding and the like, but the higher the risk of damage to the entire system," Morley said.
6. Understand the functional requirements of the connector
Suppliers need customers to fully express their needs, or they may misunderstand the needs of customers. This is especially important when you need to create a custom connector.
"It is vital to articulate the requirements of the connector," Storry said. "If it is unclear or missing, we may ignore the key requirements of the design."
7. Consider mechanical stress
Temperature, shock and vibration will produce stress between the interface and the circuit. Experts advise you should choose a connector that can avoid the effects of these forces.
"I saw cracked pieces on some PCBs," Morley said. "When the connector is firmly connected to the board or outer structure, it must be able to withstand the forces of shock and vibration, otherwise There may be cracks. "
Morley recommends that engineers use interconnection systems to minimize the build-up stresses between the mounting structure and the connection points. "There are many vendors that offer such a system," he says, "the designer should pay close attention to this."