Sanshuo Technology

Wire - to - board connector is a widely used interconnection scheme. At present, many electronic products are inseparable from the wire - to - board connector. A complete wire-to-board connector system consists of a plug (usually mounted on the PCB) and a socket (for connecting external cables) that supports the PCB's interconnection with external signals or power supplies, making the system easier to expand.

Because of the widespread use of wire-to-board connectors, there are many manufacturers and products available on the market. How to quickly select a "cutting-edge product" with high reliability in these complicated products, need developers and buyers experience enough, vision enough "poison".

However, even the toughest things have their rules, and today we'll use Molex's recently released Micro-lockPlus wire-to-board connector as an example to see how you can quickly tell if a wire-to-board connector is what you're looking for.

Figure 1: Molex Micro-lockPlus connector on board

Basic configuration of connectors

Wire-to-board connectors have some basic configurations, including pin spacing, arrangement, assembly mode, and so on. To be selected based on the requirements of application scenarios. Generally speaking, the strength of the manufacturer, will be in the same series of connector products, to provide different configuration options to maximize customer needs.

Molex's Micro-LockPlus wire-pair plate connector, for example, offers a subfamily of 1.25mm and 2mm separations that meet high connection density and compact space requirements. The 2mm spacing product adopts single row pin layout, with 2-16 channels to choose from; The 1.25mm pitch product is available in single and double row pin layouts, supporting different number of connections: single row 2-16 channels, double row 8-42 channels.

Figure 2:1. Micro-lockplus connector with 25mm pitch (source: Molex)

At the same time, as can be seen from Figure 2 and Figure 3, the two sub-families of Micro-lockPlus also offer two different PCB assembly modes, top and side, to meet the needs of different system layouts when wiring, bringing design flexibility.

In particular, the 1.25mm pitch product range is available in different shell colors. Experienced engineers know that using color to distinguish different connection loops is a very "thoughtful" arrangement that can help design and maintain complex systems with less effort.

Figure 3: Micro-lockPlus wire-to-board connector with 2mm pitch (source: Molex)

The above product configuration options provided by MolexMicro-LockPlus certainly set the bar. You can evaluate the technical strength of other wire-board connector providers by comparing their product portfolios.

Figure 4:1.25mm pitch Micro-lockPlus connector with different color versions (Molex)

Key electrical characteristics

If the basic configuration described above is the most intuitive external feature of a wire-to-board connector product, we will go inside the product to understand the other factors that determine its performance. The electrical characteristics of the connector, that is, whether the electrical connection provided by the connector is reliable, is the first thing we need to check.

Figure 5: Tin-bismuth plated contact terminals to ensure micro-lockPlus reliability in high density interconnects (Molex)

The key to electrical connection is in the contact. The current mainstream connector to provide low resistance connection, the general use of copper alloy conductor, which is almost the same as you know; The difference of the electrical connection of the product is mainly reflected in the coating of the contact. Depending on the connector's intended application, the Molex Micro-lockPlus connector does a lot of "personalization" on the contact plating.

The micro-lockplus connector, 2mm apart from the plug and socket, is tin plated. The plug of the 1.25mm pitch connector is tin-bismuth coated to help prevent tin whiskers, so the coating is designed to ensure that the microlock provides a clean and interference-free signal in high density interconnects, making the contact terminals reliable and durable.

In addition, the 1.25mm product also offers gold-plated plugs and sockets, which are especially suitable for low-pressure, low-resistance applications to further improve reliability and service life. According to Molex, a gold-plated version of the product will be available in the third quarter of 2020, giving users more options.

Figure 6: Gold-plated version of contact terminals improves reliability and longevity of Micro-LockPlus products (Molex)

In addition, micro-LockPlus optimizes the structure of the contacts, adopting a unique dual contact design and increasing the contact area between the plug terminal and the socket splint.

Figure 7: Micro-lockPlus optimization of contact architecture design (Molex)

With the aforementioned guarantees from contact with electroplated materials to structural design, micro-Lock Plus has excellent electrical connection characteristics.

Table 1: Micro-lockPlus electrical connection characteristics (Source: Molex)

Reliable mechanical properties

In order to ensure the reliable connection of wire board connectors, in addition to the electrical performance and overall mechanical structure design, but also to provide the necessary external force to ensure the electrical connection, to ensure reliable matching, but also to improve the stability of the entire connector system and its PCB components.

In order to ensure the reliability of the connection, Molex Micro-lockPlus has designed a special forward locking mechanism, in which the single-row layout connector adopts external locking, and the double-row layout product adopts internal locking, providing additional strength for the stability of the connection.

Figure 8: Latch mechanism adopted by Micro-lockPlus for enhanced connection stability (Image source: Molex)

At the same time, the socket connector of Molex Micro-lockPlus adopts wide lock design to provide enhanced grip force. When the connector is inserted correctly, the "click" sound can be clearly heard to give the user a clear indication of successful connection, which is more practical in some occasions where blind insertion is needed to prevent misinsertion.

Figure 9: Micro-LockPlus wide lock design provides enhanced retention. (Molex)

In addition, the connector socket is designed with a strong metal solder joint to ensure connector retention on the PCB, while eliminating stress on the solder joint so that the connector can withstand external environmental forces.

Figure 10: Solid metal welds on sockets for more stable assembly of micro-lockPlus on PCB. (Photo by Molex)

Finally, it must be mentioned that the case of micro-lockPlus, with its plug made of PA plastic and socket made of PBT plastic, not only meets the environmental requirements of low halogen, but also provides very good high temperature characteristics, can withstand 105℃ operating temperature, This allows micro-lockPlus to be used in industrial, automotive and other environmentally demanding applications.

Summary of wire to plate connector selection

From the above micro-lockPlus diagram, you can roughly summarize the basic requirements to consider when choosing a wire-to-plate connector. For example, abundant product configuration options, excellent electrical connection design, reliable mechanical structure, high temperature resistance, etc.

According to this standard, we have a look at Micro-LockPlus: it adopts high temperature resistant design, has extremely high electrical and mechanical performance reliability, can withstand harsh working environment, meet the requirements of automobile and other industries; Offers a rich product portfolio, 1.25mm and 2mm spacing, single and double row configurations; The product is equipped with positive lock, can firmly hold the plug, does not affect the compactness; These connectors also feature solid metal welds, wide front locks, and click connection prompts to provide all-round matching protection.

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