JPH0425677B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND OF THE INVENTION The present invention relates to solder-bearing terminal pins for attachment to sockets in circuit boards, and more particularly, the present invention relates to solder-retaining terminal pins for attachment to sockets in circuit boards, and more particularly, to mechanically hold a suitable amount of solder in place by means of a terminal pin. The invention relates to a terminal pin that is held in place and melted to connect the terminal pin to a socket to create an electrical and mechanical connection.

There are terminal pins that are made by continuously punching out thin metal sheets at high speed. Since each terminal pin carries its own amount of solder, the terminal pins are made individually but preferably attached to a common support piece for insertion by an automatic machine into a socket in the board. It may be.

When a terminal pin is inserted into a socket on a board (typically a hole drilled in the board and metal plated on the inside surface of the hole and surrounding surfaces) and the assembly is heated, the molten solder is released. Various means are available for retaining a quantity of solder on the terminal pin such that the solder covers the adjacent surfaces of the terminal pin and the socket and, when cooled, creates a soldered metallurgical bond between the terminal pin and the socket. It has been taken.

In the prior art, individual terminal pins are pushed into sockets within the board, and soldering is accomplished either by passing the entire board through a soldering machine, or by using a conventional soldering iron and wire solder to assemble the individual terminal pins into sockets in the board. This is done by soldering to the

Another method used in the prior art is
Solder was attached to each terminal pin by a metallurgical bond between the solder and the terminal pin. in this case,
The solder is placed far away from the socket on the board. This method produced a weak solder bond because the solder had to move downwards on the terminal pin before it reached the bonding point between the terminal and the socket to be soldered. .

[Disclosure of the invention]

The present invention provides a means to securely hold the appropriate amount of solder adjacent the terminal pin through mechanical attachment. At least one engagement finger member from the terminal pin wraps tightly around the appropriate amount of solder to securely hold the solder in place;
The most suitable manufacturing method is stamping. The engagement fingers tightly wrap around the solder and slightly bite into the surface of the soft solder mass to prevent the solder from becoming dislodged during preheating handling and soldering operations.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a mechanism for reliably attaching the proper amount of solder to a terminal pin by purely mechanical means.

Yet another object of the invention is to provide a solder-bearing terminal pin in which each terminal pin supplies its own solder at a convenient location for melting to form a bond with the socket.

Another object of the invention is to provide a solder and terminal pin assembly that can be manufactured by a very simple and efficient stamping process.

Still another object of the present invention is to improve the shape, structure, and combination of parts to effectively achieve the above-mentioned objects.

The invention therefore consists in the manufacture of articles having the features, properties and relationships of the elements described in detail below, and the scope of the invention is indicated in the claims.

[Best mode for carrying out the invention]

Referring to the drawings, FIG.
Two solder-bearing terminal pins connected to
It shows. The support piece 11 is provided with regularly spaced guide holes 12 in a conventional manner.
The terminal pin 10 is connected to the support piece via a breaking notch 13 so that the support piece can be removed after it has been soldered in place. Each terminal pin 10 includes a main body, a conductive member consisting of an engaging finger member,
It is composed of the main body and an appropriate amount of solder 17 in the form of a lump held by the engaging finger members. The body comprises an upper body portion 14, a lower body portion 15, an upper contact arm 18 and a lower contact arm 19, and the engagement finger member comprises two engagement fingers 16.

The support piece 11 is cut to any desired length and supports a large number of terminal pins. The terminal pins and support pieces are made by continuous stamping from thin metal sheets. During the stamping operation, the engagement fingers 16 are bent out of the plane of the terminal pin body and wrapped at least partially around the appropriate amount of solder 17. During the stamping operation, it is preferable that the engaging fingers be punched out to a thickness thinner than the thickness of the main body of the terminal pin. This allows the engaging fingers 16 to be easily wrapped around an appropriate amount of solder 17. When the free ends of the engagement fingers 16 are wrapped around the soft metal solder during the stamping operation, this wrapping is done with sufficient force to force the engagement fingers into the surface of the solder, and the solder Forms a firm mechanical attachment between the solder and the terminal pin that prevents solder from extruding during loading and transportation prior to attachment.

Referring to FIG. 2, which is a side view of FIG. 1, it can be seen that the engagement finger 16 has a thickness that is thinner than the thickness of the main body of the terminal pin. Main body parts 14, 15
The thickness of is usually determined for convenience rather than necessity.
The thicknesses of the upper and lower contact arms 18 and 19 are chosen to be the same, respectively. This thickness can also be adjusted during the stamping process.

The free end of each engagement finger 16 is spaced apart from body portion 15 to define an opening, as shown in FIG. As a result, when the assembly is heated, the molten solder flows unhindered toward the socket on the board, and the terminal pin can be reliably soldered to the socket on the board.

In use, the contact arm may be soldered to an adjacent printed circuit board, soldered to a wire or other electrical element, or serve as a pin or blade connector for an electrical plug.
Alternatively, it may also be used to provide electrical and mechanical connections. Preferably, the engagement fingers 16 are stamped from the same thin sheet metal as the remaining terminal pins. The thickness of the engagement fingers is rolled out during the stamping operation to facilitate forming them into the appropriate shape.

Upper contact arm 18 may be of any suitable shape. If desired, it may have a rectangular cross-sectional shape suitable for wire wrapping connections, or a circular cross-sectional shape suitable for soldered connections. The upper contact arm 18 may be bent or straightened out of the plane of the terminal pin, as shown in dotted lines in FIG. 2, to constitute a spring-like side contact arm. The lower contact arm 19 must be of sufficient size to pass through the socket in the board. This socket requires that its maximum cross-sectional dimension not be greater than the maximum cross-sectional dimension of the lower body portion 15. Lower contact arm 19, like upper contact arm 18, may be completely removed if desired. In the latter case, the support piece 11 may be attached directly to the upper body part 14.

FIG. 1 shows the terminal pin connected to the support piece 11. Although this is the preferred embodiment for automated machine insertion into the board, each terminal pin is attached to its own solder blob, so
The terminal pins can also be used individually when the user requires a small quantity of terminal pins. It is also possible to remove individual terminal pins from the support piece without affecting other terminal pins. This allows the terminal pin to be inserted integrally with the conventional template into the corresponding template of the socket in the board.

FIG. 3 is a front view showing details of the terminal pin of FIG. 1 inserted into socket 20 within board 21.
Substrate 21 is coated around the socket and on its inner surface with contact material. The lower body portion 15 is sized to fit tightly into a socket in the board. This socket provides good electrical contact after soldering. The socket of FIG. 3 consists of a hole drilled through a substrate 21 and plated with contact material 22. The socket of FIG.

FIG. 3 shows how engagement fingers 16 hold the solder in close proximity to lower body portion 15 and socket 20 prior to heating and before completion of the soldering operation.

FIG. 4 details the metallurgical bond formed between the terminal pin and the socket in the board after the terminal pin and board have been heated sufficiently to melt the solder. As can be seen, the solder has flowed completely around the lower body portion 15, joining the lower portion of the contact material on the board, the inner surface of the socket, and the engagement fingers 16 to the terminal pins.

FIG. 5 shows a variant of the terminal pin in which an elongated groove 23 is cut through the lower body portion 15. The elongated groove 23 and the lower body portion 15 are connected to the substrate 2.
1 and the diameter of the socket 20, the lower body portion 15 is molded slightly over the socket 20 before insertion and a compression fit is achieved after insertion. Terminal pins that create such a compression fit are commonly known as compliant terminal pins. These conformable terminal pins create a temporary bond between the terminal pin and the socket, so you can attach other electrical components before soldering without worrying that the previously inserted terminal pin will come loose during another operation. Other electrical assembly operations such as insertion can be performed. The use of elongated grooves 23 to create compliant terminal pins has the added advantage of allowing individual terminal pins to be used without being attached to the support piece, which is susceptible to slipping off the cathode when removed from the support piece. Yet another advantage associated with the use of elongated grooves 23 to create compliant terminal pins is that the grooves provide a flow path for molten solder that extends to the back side of substrate 21. This is particularly important if the cross-sectional shapes of the lower body portion 15 and the socket 20 are substantially identical. In this case, there is no elongated groove 23, which prevents the solder from reaching the back surface. Long and narrow groove 23
provides additional surface area to provide a better mechanical and electrical connection between lower body portion 15 and socket 20.

In FIG. 6, the second modification of the terminal pin is
It is shown having a single central engagement finger 24 formed from a U-shaped elongated notch 25 along the axis of the body. A U-shaped elongated notch 25 extends below the axis of the lower body portion 15 to serve the same function as the elongated groove 23 made to provide a compliant terminal pin.

FIG. 7 is a side view of the second modification shown in FIG. 6. As can be seen in FIGS. 2 and 7, the engagement fingers 16 and 24 are partially wrapped around a suitable amount of solder 17 within the space formed between the engagement fingers and the body of the terminal pin. Holds the solder 17.
The engagement fingers can be wrapped partially or completely around the appropriate amount of solder as desired, and
The solder may be of any suitable shape. When only a single engagement finger is used to attach to prevent the solder from coming off before heating,
It is particularly valuable in allowing the engagement fingers to dig into the soft solder mass.

Figure 8 shows a third
It is a front view of two terminal pins of a modification. Both the upper support piece 27 and the lower support piece 28 are provided with conventional guide holes 12. In this variation, the upper contact arm 29 is a cantilevered spring blade contact with a central elongated groove 30 that provides additional spring action to the upper contact arm 29. The two common support pieces 27, 28 provide additional rigidity to the attached terminal pins. This rigidity maintains accurate alignment during loading and handling prior to insertion of the terminal pin into the socket.

FIG. 9 is a side view of the third modification shown in FIG. 8. As can be seen from this figure, the upper contact arm 29 is stamped to a thickness less than that of the body of the terminal pin, providing an additional spring action. The upper cutting notch 31 and the lower cutting notch 32 are also clearly visible in this figure.

In each of the terminal pins described above, the engagement of the terminal is such that a suitable amount of solder is melted to form a bond between the engagement fingers 16 of the terminal, the body 14, 15, and the socket 20 of the substrate 21. Mechanically engaging the finger in place. A suitable amount of solder may have a circular, square, or other geometric cross-section, or may be made from spherical pellets, as desired.

Although FIG. 8 is depicted as having two engaging fingers 16, it is configured to have a single central engaging finger 24, as shown in FIGS. 6 and 7. Good too. It may be constructed with or without a central elongated groove 30 or the elongated groove 23 described above. Additionally, lower support piece 28 may be used in conjunction with any of the terminal pins shown. If such a lower support piece is used, the upper support piece is optional. Each terminal can be made by a simple stamping and assembly process with minimal material consumption.

As is clear from the foregoing, the foregoing objects are effectively achieved, and since certain changes may be made without departing from the spirit and scope of the invention, it is contemplated that the foregoing and accompanying drawings may be incorporated herein by reference. All matter set forth is to be interpreted as indicative and without limitation.

[Brief explanation of drawings]

FIG. 1 is a plan view showing two terminal pins according to the invention attached to a common support piece. FIG. 2 is a side view of the terminal pin shown in FIG. 1. FIG. 3 is a partial plan view showing the terminal pin according to FIG. 1 inserted into the socket before heating; Figure 4 is a partial plan view similar to Figure 3 after sufficient heat has been applied to melt the solder and create a flow metallurgical bond; FIG. 5 is a partial plan view showing a first modification of the terminal pin shown in FIG. 3.
FIG. 6 is a partial plan view showing a second modification of the terminal pin shown in FIG. 1. FIG. 7 is a partial side view of the modification shown in FIG. 6. FIG. 8 is a partial plan view showing two terminal pins of a third modification attached to two common support pieces. FIG. 9 is a side view of the terminal pin shown in FIG. 8. 10...Solder holding terminal pin, 11...Support piece, 14...Upper body portion, 15...Lower body portion, 16...Engagement finger, 17...Appropriate amount of solder in the form of a lump, 18...Upper contact Arm, 19... Lower contact arm, 20... Socket, 21... Board, 23...
Elongated groove, 24... Central engagement finger, 25... Elongated notch, 27... Upper support piece, 28... Lower support piece, 29... Upper contact arm, 30... Elongated groove.

Claims (1)

[Scope of Claims] 1. A terminal pin for making an electrical connection with a contact material on a substrate, comprising an elongated body and a finger member bent from the body, and the body and the finger member are connected to each other. a conductive member forming a space between the conductive member and a solder lump held within the space by the conductive member, the finger member engaging the solder lump and pushing the solder lump against the main body. mechanically attaching the solder mass to the body by holding the finger member, the free end of the finger member being spaced apart from the body so as to form an opening communicating with the space, and having a terminal pin attached to the substrate. the contact material on the substrate, and the opening between the body and the finger member allows the heated and melted solder to contact the free end of the finger member and the contact material on the substrate. A terminal pin oriented along the body to provide a passageway for flow between the terminal pins. 2. The terminal pin according to claim 1, wherein the finger member is an elastic engagement finger formed integrally with the main body. 3. The terminal pin according to claim 2, wherein the engaging finger partially wraps around the solder mass to hold the solder mass. 4. The terminal pin according to claim 2 or 3, wherein a surface portion of the solder mass located on the opening side is directly bonded to a contact material on a substrate. 5. Terminal pin according to any one of claims 1 to 4, characterized in that the body has a contact arm adapted to be inserted into a plated aperture in a substrate. 6. The terminal pin according to claim 5, wherein the finger member comprises two engaging fingers, and the solder mass is held in a space between the two engaging fingers and the main body. 7. the body has a slot along the contact arm;
7. A terminal pin according to claim 5, wherein the contact arm is slightly larger than the size of the aperture so as to be elastically held within the aperture of the substrate. 8. The terminal pin of claim 7, wherein the slot and contact arm are adapted to form a compression bond between the aperture in the substrate and the contact arm. 9. A method of soldering a terminal pin to a conductive area of a substrate, the method comprising: providing a conductive terminal pin having an elongated body, the body having a first end integrally attached thereto and a free end spaced apart from the body; and a finger having a finger bent around and engaging the solder mass and holding the solder mass to the body, and holding a portion of the solder mass between the free end of the finger and the body. exposing, placing the terminal pin on the substrate such that a conductive area of the substrate is juxtaposed and directly opposite the exposed solder blob portion without a finger inserted between the solder blob and the conductive area; A method of soldering a terminal pin to a conductive area of a substrate, the method comprising heating and melting the solder mass and soldering the terminal pin to the conductive area when cooled. 10. In the combination of a substrate having a conductive area, a terminal pin soldering to the conductive area, and a solder lump, the terminal pin has an elongated body and a finger, and the finger has a second body integrally attached to the body. one end and a free end spaced apart from the body, the fingers being bent around and engaging the solder mass and mechanically retaining the solder mass to the body; left exposed between the free end and the body, the exposed solder mass portion being directly juxtaposed opposite a conductive area of the substrate, and contacting the conductive area upon melting the solder mass; A combination characterized in that the terminal pin is soldered to the conductive area in an unobstructed flow.