The invention relates to a shielded electrical connector, more particularly to an electrical connector with a shielding member that is capable of providing effective protection against electromagnetic interference.
Connectors are often used for signal transmission among the various electrical components in a computer. Referring to FIG. 1, a conventional electrical connector is shown to include a generally rectangular housing 10 made of an insulator material. The housing 10 has a front side formed with a receiving chamber 101 and a socket 102 formed in the receiving chamber 101. The socket 102 has contact insert holes 103 for electrically and mechanically engaging a complementary electrical connector (not shown). A plurality of terminals 104 are disposed in the insert holes 103, respectively, and have tips that extend downwardly from the bottom side of the housing 10 for electrical connection with a circuit board (not shown). The electrical connector further includes a shielding unit to prevent external electromagnetic waves from interfering and affecting signal quality during signal transmission.
The shielding unit includes first and second shielding components 20, 25 that cover the housing 10. The first shielding component 20 includes top, rear, left and right wall portions 21, and covers four sides of the housing 10 (excluding the front side and the bottom side). The bottom edge of the first shielding component 20 is formed with grounding legs 22 for grounding purposes. The second shielding component 25 has two sides formed with a respective thorn 251 for fixing the second shielding component 25 in a space formed between the inner wall surface of the receiving chamber 101 and the socket 102. The bottom edge of the second shielding component 25 is also formed with a grounding leg 252 for grounding purposes.
It is noted that the protection against electromagnetic interference in the aforementioned conventional electrical connector is inadequate since no shielding effect is provided at the front side of the socket 102.
FIG. 2 illustrates another conventional electrical connector with a shielding unit. As shown, the electrical connector includes a generally rectangular housing 10' made of an insulator material. Like the housing 10 of the electrical connector of FIG. 1, the housing 10' has a front side formed with a receiving chamber 101', and a socket 102' formed in the receiving chamber 101'. The socket 102' has contact insert holes 103' for engaging electrically and mechanically a complementary electrical connector (not shown). A plurality of terminals (not shown) are disposed in the insert holes 103', respectively, and have tips that extend downwardly from the bottom side of the housing 10' for electrical connection with a circuit board (not shown). The left and right sides of the housing 10' are formed with a respective fastening recess 105. The electrical connector further includes a shielding unit to prevent external electromagnetic waves from interfering and affecting signal quality during signal transmission.
The shielding unit is similar to that disclosed in U.S. Pat. No. 5,637,015 issued on Jun. 10, 1997 to Hon Hai Precision Ind. Co., Ltd., and includes first and second shielding components 30, 35 that cover the housing 10'. The first shielding component 30 includes a front wall portion 31 and left and right wall portions 32. The front wall portion 31 is formed with a circular opening 311, and a rearwardly extending guide piece 312 at the periphery of the opening 311. The top edge of the front wall portion 31, is bent rearward to form a press section 313. Each of the left and right wall portions 31 has an engaging section 321 that is formed with a slit 3211. The top edge of each of the left and right wall portions 32 is formed with a stepped section 322. The bottom edge of each of the left and right wall portions 32 is formed with a downwardly extending grounding leg 323. The second shielding component 35 includes a top wall portion 351 and a rear wall portion 352. The rear wall portion 352 has forwardly projecting insert section 353 at left and right edges thereof. Each insert section 353 has a resilient piece 354 thereon. The front edge of the top wall portion 351 is formed with a stepped section 355. The left and right edges of the top wall portion 351 are bent downwardly to form a respective press section 356.
The first shielding component 30 is mounted on the housing 10' at the front side of the latter so as to cover and be positioned on the front side and the left and right sides of the housing 10'. The second shielding component 35 is mounted on the housing 10' at the rear side of the same so as to cover and be positioned on the top and rear sides of the housing 10'.
The front wall portion 31 of the first shielding component 30 provides the electrical connector of FIG. 2 with stronger protection against electromagnetic interference than that in the electrical connector of FIG. 1. However, the electrical connector of FIG. 2 still has an unsatisfactory design due to the following reasons: From the manufacturer's viewpoint, there is a need to form two separate components; i.e., the first shielding component 30 with the front wall portion and the left and right wall portions, and the second shielding component 35 with the top and rear wall portions. During the manufacturing stage, the two components undergo separate processing operations. Particularly, two dies must be prepared when forming the two components. For each mold, the precision of the corners in the other mold must be taken into consideration. Furthermore, the corresponding angles of the press sections 313, 356 and the stepped sections 322, 355 that project from the edges of the two shielding components must be precisely matched. The high quality requirement during the die forming and production stages is troublesome and results in increased costs. In addition, because the two shielding components are mounted on the housing one after the other, and because the shapes of the shielding components have been set beforehand, extreme care must be undertaken when bending the different portions of the shielding components during the mounting of the same so as to avoid any deviation which can hinder precise mounting of the shielding components on the housing. This increases the difficulty in mounting the shielding components on the housing. Moreover, clearances between the shielding components cannot be entirely avoided when the shielding components are mounted on the housing. These clearances can have an adverse effect on the protection against electromagnetic interference.