At present, with the popularization of SMT technology, the application of surface mount connectors has become more and more widespread, and various types of PCBs have corresponding surface mount connectors. From the perforated (T/H) soldering process to the surface mount (SMT) soldering process, the pitch of the connector terminals can be reduced from 1.27mm to 1.0mm and gradually reduced to 0.8mm and 0.5mm. Moreover, the use of the SMT process allows the electronic components in both sides of the PCB to greatly increase the density of the components of the PCB.

Nowadays, various consumer electronic products using connectors have been integrated into miniaturization, thinning and high performance, which has led to the development of corresponding connectors to shorten and link to narrow-form development. In the connector products of Board to Board (BTB), companies have begun mass production of 0.5mm chip connector products. This type of connector is converted from a conventional plug to a narrow-lead contact for a jack contact, and a perforated soldering process is converted to a surface mount soldering process, which is reduced from a terminal arrangement pitch of 1.27 mm to 0.5 mm, which represents the future. The development trend and mainstream of electrical connectors.

The BTB connector is used to connect two PVBs of the connector to make mechanical and electrical connections. It is characterized by the male and female connectors being used in pairs, so the replacement of the connectors and the terminals have strict requirements. In order to meet the requirements of the SMT process, the terminal soldering area of ​​the entire product is strictly required to have good flatness and coplanarity. Generally, the industry standard is a coplanarity of 0.1mm Max. Otherwise, it will cause poor soldering with the PCB. Use of the product.