Summary of common problems in connector selection of TF card holder and SIM card holder

If you choose a SIM card socket connector for your project, you need to consider the following considerations while choosing the connector requirements:

How many contacts does the connector need?

How to install the connector you want to use?

What is the method of installation and what is required for installation?

What kind of termination method do you want to use for your application?

Does the connector used need intrusion protection?

How much voltage and current do you expect to withstand when connecting?

As the connector power capacity continues to increase, you will find that the total number of contacts for any package and shell size will drop. This is because more space is required due to the larger wire gauge and higher voltage. So some manufacturers try to increase the rated voltage by adding more isolation between the contacts and increasing the total "distance" of the arc from one contact to another. In addition, some connectors have ground contacts built into the remaining contacts. These contacts are longer than the other contacts in the connector and are used to reduce/eliminate arcs between two mating/non-engaging connectors.

1. Number of contacts The following points should be kept in mind and considered when selecting a connector:

How many connectors and contacts do you need or want to use for power input/output enclosures?

What is the general contact combination type of the connector?

Only the power contacts?

Signal contact only?

Power and signal contacts?

Signal + ground contact?

For projects where only one connector can be used, may need to use a slightly larger connector to accommodate all contacts?

If the signal and power contacts are to be separated, the space required for installation will increase. However, this may be the general layout requirements of the application, or is the function of the application such that the two contacts have to be separated?

Second, installation type

PCB pin through hole-the terminal pin of the connector, through the through hole on the circuit board, and the circuit board where the connector is mounted/fixed?

PCB surface mount-mount/fix the connector to the circuit board through the terminal pins of the connector, and the pins are placed on the contact pads on the surface of the circuit board?

Panel installation-There are reserved holes on the surface or panel, and the connector passes through the hole or is placed against the hole. Since the connector is installed on the circuit board behind the panel, can the fixing method be threaded and nut or directly fixed in place?

Free hanging/cable mounting-the connector is mounted/mounted to its terminated cable?

Circuit board/card edge/prepared hole mounting-For card edges, the termination is close to the edge of the circuit board, and in many cases the connector will be modified for use at the edge. For the reserved holes on the board, the situation is similar because they are close to the edge of the circuit board. However, a part of the circuit board has holes reserved so that the connector has a flat profile. These two types of installation methods are to achieve a flatter overall appearance of the circuit board. In addition, when there is a lack of available space on the circuit board, or for other design requirements, these two types of connections can also be used?

Through-board mounting-similar to reserved hole mounting, but the difference is that this type of connector is not commonly found near the edge of the circuit board. Since they are installed through reserved holes on the circuit board, they are also similar to panel mount connectors. Some are terminated with through holes in the circuit board and soldered on the same side of the connector mating, others are surface mounted to the side of the circuit board where they are mounted (the opposite side of the connector mating side)?

3. Installation method

The terms "installation" and "termination" are often used interchangeably, but it should be remembered that they are not always interchangeable. There is a difference between the two. Installation refers to how the entire project and the connector are connected/fixed/attached as a whole. Termination refers to how to make electrical connections. Through-hole mounting and surface mounting in most cases refer to connectors that can be mounted and terminated in a specific way.

Four. Termination method

What termination method is required for each end or each connection? If there are no specific types of requirements specified in advance, the termination method can be determined by personal preference. However, some applications may require a specific type of termination

Solder termination-For connectors, this termination method is suitable for many applications. However, if it is an application in a high temperature area, more mechanical termination methods may need to be considered. Soldering can be used for wire termination and circuit board termination connections. Therefore, this type of termination includes a variety of connector welding methods. Through-hole soldering and surface mounting as described above, describe a type of mounting and termination.

Through-hole soldering-pins are left on the terminal side of the connector, which is suitable for passing through the pre-perforated holes on the circuit board, and copper pads are usually laid on the opposite side of the circuit board on the access side of the through-hole connector. After placing it in place, it will be welded and fixed.

Surface mount termination-The connector pins and mounting pads are on the same side of the PCB. The connector can be manually placed and soldered in place, or soldered in place by reflow soldering and wave soldering. Note that some circuit board/card edge connectors are also surface mount types.

Crimping-This type of termination is very robust and reliable and can be used to terminate wires. However, this depends on the quality of the crimp and the correct installation in the contact housing. In order to achieve high-quality crimping and overall connection, it is necessary to ensure that the correct contacts and the correct crimping tools are used for the housing. For these contacts, tool selection is an important step. If the final quality is not a key consideration, other tools or lower-cost devices can be used. However, if you want to consider the final quality, you need to use the tools recommended by the manufacturer, the relevant wire preparation steps, and any crimp quality data provided by the manufacturer for post-crimp inspection (note: not all inspections are required, just sample verification That's it). If the correct tools and procedures are not used, and the connection is wrong, most manufacturers of this type of connector will not provide support or warranty.

Press-in/plug-in-This type can be either a permanent termination or a releasable termination, and it also has quite good reliability and robustness. However, if it is used in a high-vibration environment, it is recommended to check the anti-vibration strength of the connector. This type of termination usually only needs to peel the wire and press it into the connector, or activate the locking lever to the unlocked state, insert the wire, and move the locking lever to the locked state. For the type that can loosen the wire, some mechanism can be built into the connector, or a tool such as a flat-blade screwdriver needs to be pressed into the groove of the housing.

Five. Environmental factors

If in a relatively ordinary application environment, no extreme conditions are expected to occur, then almost any connector can be suitable for the specified specific needs. But when designing a project for a harsh application environment—for example, the connectors used may encounter vibration, motion shock, shielding, environmental intrusion, as well as oil, solvent, or any kind of chemicals and corrosion—you must keep these characteristics in mind during the selection process.

Six. Rated current and voltage

How much rated current is required

When choosing a connector, you should choose a connector that can handle the maximum expected current.

It is recommended to choose a connector that can handle higher than expected current as much as possible to provide margin for any unexpected overcurrent.
If it is a board-mounted connector, try to find the mating point where the cable is installed. The wire gauge of the connector can be used to find the rated current.

What kind of rated voltage needs to be processed? If the specific connector you are looking for does not list the voltage-you can consult other connectors with the same or very similar contact spacing and physical structure, some of which will indicate the voltage that can be handled; if no rated voltage data is provided, You need to contact the connector manufacturer. It is recommended that you contact Dongguan Xunpu Electronics, which is a professional manufacturer of TF card sockets and SIM card sockets.