# Patent

## Title
Electrical connector having improved contact terminal

## Abstract

An electrical connector (100) is soldered to a circuit board (4) via a number of solder members (3) and includes an insulative housing defining a number of passageways (12), and a number of contact terminals (2) inserted in the passageways respectively. Each contact terminal has a body portion (21) secured in the passageway, and a tail portion (23) extending from the body portion and inserted through the solder member then into the circuit board. The tail portion of the contact terminal has an interfering portion (231) interlocked with the solder member and a blocking portion (232) extending from the interfering portion and restricting the solder member above the blocking portion.

## Background
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electrical connector, and particularly to a socket connector having improved contact terminals with solder mass interlocked thereto.
2. Description of Related Art
U.S. Pub. Patent No. 2008/0113544 published on May 15, 2008 discloses an electrical connector. The electrical connector comprises an insulative housing defining a plurality of passageways and a plurality of contact terminals received in the passageways. Each contact terminal is formed with a body portion and a resilient beam extending from the body portion. A free end of the body portion is inserted into a middle portion of the solder ball and would not inserted through the solder ball. The electrical connector is soldered onto a circuit board when the solder balls are melted under a high-temperature condition.
The body portion of the contact terminal is inserted in a middle portion of the solder ball. The solder ball is easy to drop from the contact terminal to result in an insufficient soldering effect.
U.S. Pat. No. 5,029,748 issued to Lauterback on Jul. 9, 1991 discloses an electrical connector. The electrical connector comprises a plurality of pins, a carrier film carrying a plurality of upper and lower solders respectively disposed at an upper surface and a lower surface of the carrier film. The pins insert through the upper solders, the carrier, the lower solders, and a plurality of through holes defined in a circuit board, in sequenced.
The solders are easy to drop from the contact terminals to result in an insufficient soldering effect.
Hence, an electrical connector having improved contact terminals is required to overcome the above-mentioned disadvantages of the related art.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an electrical connector having improved contact terminals each interlocked with the solder member and preventing the solder member from dropping, for realizing a sufficient soldering effect.
To achieve the aforementioned objects, an electrical connector is soldered to a circuit board via a number of solder members. The electrical connector includes an insulative housing defining a number of passageways, and a number of contact terminals inserted in the passageways respectively. Each contact terminal has a body portion secured in the passageway, a resilient beam connected with the body portion, and a tail portion extending from the body portion and inserted through the solder member then into the circuit board. The tail portion has an interfering portion interlocked with the solder member and a blocking portion preventing the solder member from dropping.
The interfering portion of the contact terminal interlocks with the solder member and the blocking portion prevents the solder member from dropping. Therefore, the electrical connector could be soldered on the circuit board sufficiently via adequate number of solder members.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of a preferred embodiment when taken in conjunction with the accompanying drawings.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional perspective view showing an unit of an electrical connector connecting with a circuit board via a soldering donut in accordance with the present invention;
FIG. 2 is a sectional view of the unit of the electrical connector, a soldering donut and a circuit board, with the unit and the soldering donut being partially cut away to show the assembly of the unit and the soldering donut;
FIG. 3 is an exploded perspective view of the electrical connector, the soldering donut, and the circuit board as shown in FIG. 1; and
FIG. 4 is a schematic view showing the engagement between the contact terminal and the soldering donut, with the part showing the soldering donut being a cross-sectional view of the soldering donut.



DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made to the drawing figures to describe the present invention in detail. Referring to FIGS. 1-4, an electrical connector 100 made in accordance with the preferred embodiment of the present invention comprises an insulative housing 1 having a base portion 11 defining a plurality passageways 12 therethrough, and a plurality of contact terminals 2 secured in the passageways 12. The electrical connector 100 is adapted for being soldered onto a circuit board 4 via a plurality of soldering donut 3 interlocked on the contact terminals 2. One passageway 12 and corresponding one contact terminal 2 are regarded as one unit of the electrical connector 100. FIGS. 1-4 show only one unit of the electrical connector 100.
Referring to FIGS. 3 and 4, the contact terminal 2 comprises a body portion 21, a bridge 22 bent from the body portion 21 and a tail portion 23 extending downwardly from the body portion 21. The body portion 21 is formed with a blade portion 210 and a securing portion 211 standing upwardly from the blade portion 210, and a pair of barb portions 212 projecting from opposite sides of the blade portion 210. The bridge 22 is formed with a bent portion 220 bent from an inner side edge of the securing portion 211, and a resilient beam 221 extending upwardly from the bent portion 220. The resilient beam 221 has an arcuate contact portion 222 formed at a tip end of the resilient beam 221. The angle between the securing portion 211 and the bent portion 220 is 145 degree in general. The angle between the securing portion 211 and the resilient beam 221 is 45 degree generally.
The tail portion 23 extends from the body portion 21 and comprises an interfering portion 231 and a blocking portion 232 continuing from the interfering portion 231. The interfering portion 231 and the blocking portion 232 are formed into a plate portion. The blocking portion 232 has a width greater than that of the interfering portion 231. Optionally, the interfering portion 231 and the blocking portion 232 could be formed into a columnar configuration, in a condition that the diameter of the blocking portion 232 is greater than that of the interfering portion 231.
The soldering donut 3 has a through hole 31 defined therethrough. Optionally, the soldering donut 3 could be formed into a solder ball or any other configurations.
The circuit board 4 has a mounting hole 41 defined therein.
Referring to FIGS. 1-4, in assembling of the electrical connector 100, the contact terminal 2 is inserted into the passageway 12 of the insulative housing 1, with the resilient beam 221 and the tail portion 23 respectively extending outward of the passageway 12 from an upper and a lower portion of the passageway 12. The interfering portion 231 of the contact terminal 2 is inserted through the through hole 31 of the soldering donut 3. The soldering donut 31 is prevented from dropping off the tail portion 23 due to the interengagement with the blocking portion 232. The soldering donut 31 is exposed outside of the passageway 12 of the insulative housing 1.
The electrical connector 100 is mounted onto the circuit board 4, with the soldering donut 3 disposed above the circuit board 4 and the blocking portion 232 of the contact terminal 2 inserted into the mounting hole 41 of the circuit board 4. During the reflowing process, the soldering donut 3 is melted and the electrical connector 100 is soldered onto the circuit board 4 firmly.
The donut 3 is interlocked with the interfering portion 231 of the contact terminal 2 and is protected from dropping off interfering portion 231 via the support of the blocking portion 232. Therefore, the electrical connector 100 could be soldered on the circuit board 4 sufficiently via sufficient number of soldering donuts 3.
Referring to FIG. 2, the soldering donut 3 is disposed between the base 11 and the circuit board 4. The soldering donut 3 is not received in the passageway 12 and would not collide the base 11 when the soldering donut 3 is expanded during reflowing process. The soldering donut 3 would be protected and it may result in a sufficient soldering effect.
However, the disclosure is illustrative only, changes may be made in detail, especially in matter of shape, size, and arrangement of parts within the principles of the invention.

## Claims

1. An electrical connector soldered to a circuit board via a plurality of solder members, comprising: an insulative housing defining a plurality of passageways; a plurality of contact terminals inserted in the passageways respectively, each contact terminal having a body portion secured in the passageway, a resilient beam connected with the body portion, and a tail portion extending from the body portion and inserted through the solder member then into the circuit board, said tail portion of the contact terminal having an interfering portion interlocked with the solder member and a blocking portion extending from the interfering portion and restricting the solder member above the blocking portion, wherein said body portion of the contact terminal comprises a blade portion and a securing portion standing from the blade portion, and wherein said contact terminal comprises a bridge having a bent portion bent from an inner side edge of the securing portion, wherein said resilient beam extends from the bent portion and has an arcuate contact portion formed at a free end of the resilient beam, wherein said blade portion of the contact terminal has a pair of barb portions formed at opposite sides thereof for interfering with the passageway.

2. The electrical connector as claimed in claim 1, wherein said tail portion of the contact terminal is formed into a plate portion, said blocking portion having a width greater than that of the interfering portion.

3. The electrical connector as claimed in claim 1, wherein said tail portion of the contact terminal is formed into a donut configuration, said blocking portion having a diameter greater than that of the interfering portion.

4. The electrical connector as claimed in claim 1, wherein said blocking portion of the contact terminal is inserted into the circuit board.

5. The electrical connector as claimed in claim 1, wherein said interfering portion of the contact terminal is disposed below the passageway to expose the solder member outside of the passageway.

6. An electrical connector assembly, comprising: an insulative housing defining a plurality of passageways; a plurality of contact terminals inserted in the passageways respectively, each contact terminal having a body portion, a resilient beam connected with the body portion and a tail portion extending from the body portion; a plurality of solder members each defining a through hole; a circuit board defining a plurality of mounting holes, said tail portion of the contact terminal inserting through the through hole of the solder member and the mounting hole of the circuit board, said tail portion of the contact terminal comprising an interfering portion and a blocking portion continuing from the interfering portion, said solder member interlocked with the interfering portion and prevented from dropping off the blocking portion, wherein said body portion of the contact terminal comprises a blade portion and a securing portion standing from the blade portion, and wherein said contact terminal comprises a bridge having a bent portion bent from an inner side edge of the securing portion, wherein said resilient beam extends from the bent portion and has an arcuate contact portion formed at a free end of the resilient beam, wherein said blade portion of the contact terminal has a pair of barb portions formed at opposite sides thereof for interfering with the passageway.