The reason is simple: the products are getting smaller. Nowadays, the innumerable electronic devices such as smart phones, tablet PCs, and blood glucose detectors have become increasingly stringent in terms of size, and the internals have become more and more compact, leaving little space for connectors. This trend also appears in the defense and aerospace industries, such as satellites, guided missiles, and avionics systems, where compactness requires only "miniature" connectors to be satisfied.
  As the demand for smaller connectors continues to rise, design engineers face a series of new challenges. They can no longer complete the design of the connector at the final stage of the project. Miniature connectors need to be forethought. It requires designers to anticipate various factors such as packaging, durability, current load capability, and replaceability.

Designers should consider the ease of replacement, especially in enclosed enclosures. The Molex VITA 67 is an easy-to-change miniature connector.
  Here are some design suggestions from micro-connector vendors. These suggestions not only come from the expert of the connector design, but also a tragic experience of the designer, so it is worth the designer's reference.
  
  1, consider the connector early in the design
  “Engineers tend to focus too much on designing the overall system and then consider putting the connectors in the final stages of design before considering them.” said Mitch Storry, director of product development engineering at TE Connectivity. “They think the connectors are simple, so they can put the relevant The design is in the final stage. Then they are stuck with their own designs."
  Storry has seen too many designers rush to design the connector in the final stages of design. He told us that in many cases, designers have to finally choose non-standard connectors to complete the design, which not only increases the cost but also delays the delivery time.
  To avoid this problem, experts suggest that you should consider the connectors that you will use early in the design, and then reserve space for them, and the design will also develop around them.
  "Nobody's going to hear you say, 'First, decide on the connectors you need'," said Stephen T. Morley, TE Connectivity product development engineer. "But if they do, they can actually save them a lot of time and less. A lot of trouble."
  
  2. Understand the limitations of space
  Although miniature board-to-board connectors typically have a thickness of less than 1 mm, they are also commonly used in tightly packed applications. To address potential packaging issues, designers need to consider the traces on the PCB board and additional wires attached to the connector. "Because the spacing becomes smaller, you must make the traces and wires narrower."
  Also, keep in mind that some connectors (such as flexible cable connectors) provide options for flipping forward and backward. When designing your system, you need to consider these flipping methods. For example, a connector that flips backwards may not be easily accessible if it has another component on the back.
  Finally, designers 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. Understand the current load capacity
  As the connector size decreases, the current load capability of the connector also decreases. In general, micro-connectors can handle currents between 200mA and 500mA, which is almost half the rated current of a larger board-to-board connector. In order to compensate for the problem of lower current carrying capacity, designers may need to increase the number of terminals.
  
  4. Consider the stability of small/miniature connection
  "I need to suggest this, not only at the design stage, but also during the assembly process to ensure that they are not damaged," said TE Connectivity's Morley.
  Morley, a micro connector design expert in RF applications, recalls that half of the connectors he designed for military and space applications were destroyed during the testing phase.
  If you do not focus on this issue first, you may push up costs, he said. Damaged connectors need to be reconfigured, refurbished, and marked. It may even require more expensive, field-replaceable connectors to replace, and such changes may extend the design time by one to two weeks.
  Morley said: "It should be noted that always give priority to existing connectors, if these connectors are not compatible with your design, then consider their own design, which can save you a lot of time."
  
  5. Consider ease of replacement
  If the appearance of the product is closed, then you need a connector that can be replaced from the outside. Otherwise, you will need to do some welding work.
  Morley said: "The more you do, the more skilled you are for welding and other skills, but the higher the risk of damage to the entire system."
  
  6. Understand the functional requirements of the connector
  Suppliers need customers to fully express their needs, otherwise they may misunderstand customer needs. This is especially important when you need to make custom connectors.
  "Clarifying exactly the needs of the connector is critical," Storry said. "If the statement is unclear or missing, we may ignore the key design requirements."
  
  7. Consider mechanical stress
  Temperature, shock, and vibration can create stresses between the interface and the circuit. Experts suggest that you should choose connectors that can avoid these forces.
  "I saw cracked solder joints on some PCBs," Morley said. "When the connector is firmly attached to the board or the external structure, it must be able to withstand the impact and vibration, otherwise it will Cracks may appear."
  Morley recommends that engineers use interconnection systems to minimize build-up stress between the mounting structure and the connection points. "There are many vendors that offer such a system," he said. "The designer should pay close attention to this."