JPH0817099B2 - Surface mount type electric component and manufacturing method thereof - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electric component, in particular, an electric component (device) such as a surface-mounted (surface-mounted) electric connector and a manufacturing method thereof.

(Prior Art) Recently, when connecting a lead extending from an electric component to a conductor on a circuit board, it is common to mount the electric component on the same surface as the surface of the circuit board on which the conductor is provided. Is becoming. To implement this surface mount method, the conductors of the circuit board are provided with terminal pads or regions, while the leads extending from the electrical component are provided with contact portions that are pressed against the terminal pads. The pads are covered with a viscous solder alloy material, the electrical components are placed on the surface of the circuit board, and then the solder alloy material is reflow-melted to bond the leads to the corresponding terminal pads.

U.S. Pat. No. 4,210,376 discloses a connector provided with a plurality of electrical terminal portions which connect to circuit boards through holes. By arranging the terminal portions of the connector in two rows spaced apart from each other along the rear surface of the housing, the lead ends are arranged in two rows of staggered terminals. The connector can also be converted to a surface mount type by bending the lead ends upward to contact the surface of the circuit board rather than through the holes in the circuit board.

There are several issues to be aware of when converting the more common terminal post and circuit board hole mounting method to the surface mounting method. For example, the contact parts of the leads extending from the electrical parts are accurately positioned so that they are on the same plane, and when the electrical parts are placed on the circuit board for soldering, the contact parts of the leads are placed on the circuit board. It must be able to be pressed against the corresponding terminal pad. If the lead or leads are not coplanar, the connector must be pressed towards the circuit board so that all contacts make contact with their respective surface mount pads. For successful reflow soldering, it is necessary to apply a certain force to the terminal pad through the contact portion of the terminal, for example, elastic deformation of the terminal when the connector is placed on the circuit board. If the contacts are not on the same plane, in order to align all contacts with their respective pads on the circuit board, the contacts on the plane closer to the circuit board are located farther from the board. Need to bend more than. When the deflection of some of the terminals is increased as described above, the biasing force to the lead contact portion correspondingly increases.

(Problems to be Solved by the Invention) When the biasing force is increased as described above, the connector itself is easily detached from the printed circuit board. Generally, the mounting surface of the connector is provided with a holding mechanism as disclosed, for example, in U.S. Pat. No. 4,195,900. This has a structure in which the connector is fixed to the housing by passing through the opening of the circuit board. When the urging force applied to the holding member is increased, the holding mechanism loses the urging force and the housing of the connector is easily separated from the surface of the circuit board.

Another problem with surface mount connectors of the type described above relates to lateral alignment of the lead ends for accurate placement of the lead ends on the circuit board. The lead ends are spaced 1.27 mm (0.050 inches) apart from each other, but in order to keep the lead ends in contact with the printed circuit board and to prevent the lead ends from touching each other, use this Need to be positioned accurately.

A further problem arises when the terminals are fixed to the housing using barbs. When force is applied to the lead portion of the terminal, the barb and corresponding lead retracts from the channel through the same path as it entered the channel. This retraction is greater in the case of surface mount connectors where the resilience of the contacts exerts a reaction force on the surface mount contacts when the connector is placed on the circuit board and the contacts are not yet soldered to the terminal pads. This biasing force causes the leads to pop out of the channel when the connector is attached to the circuit board, making it very difficult to properly position the leads with respect to the pads on the circuit board.

Accordingly, it is an object of the present invention to provide a surface mount connector having coplanarly arranged lead contact surfaces.

It is a further object of the present invention to provide a connector with improved lateral alignment so that it can be accurately positioned with respect to the circuit board.

A further object of the present invention is to provide a connector with improved fixability of the lead ends of the terminals to the housing.

(Means for Solving the Problem and Its Action) A surface mount type electric component according to the present invention has a plurality of leads extending outward from a side surface of an insulating housing and surface mounted on a terminal pad of a circuit board. A recess formed inwardly of the insulating housing by a plurality of channels formed in parallel to each other on the side surface of the insulating housing, and a pair of flanges communicating with the channels and facing each other. And a plurality of leads arranged in the channel, abutting on the flange and curved and fixed inwardly of the recess, and the tips of which are contact points, and the contact points of the leads are substantially flush with each other. It is characterized by doing.

A method of manufacturing an electrical component according to the present invention is a method of manufacturing an electrical component having a plurality of leads that extend outward from a side surface of an insulating housing and are surface-mounted on a terminal pad of a circuit board. Forming a plurality of channels having inwardly extending recesses between a pair of flanges facing each other, arranging a plurality of elastic leads having barbs in the channels, and attaching the barbs of the leads to the flanges. One of them is engaged with the vicinity of one of them, and the lead is pressed and curved inward of the recess by using a tool, and the tips of the leads are extended to the outside of the insulating housing and aligned in substantially the same plane. It is characterized in that a contact portion is formed.

In one embodiment of the invention, the electrical component surface mounted to the circuit board surface is orthogonal to the mounting surface adjacent to and facing the circuit surface when the electrical component is mounted to the circuit board surface. An insulating housing having a side surface extending in the direction. A plurality of leads spaced apart from each other extend from the side surface, and each of the leads is provided with an adjoining portion and an end portion adjacent to the side surface. The terminal portion is provided with a contact portion that is connected to the conductor of the circuit board when the electric component is attached to the surface of the circuit board. This electrical component has a positioning portion on its side surface, while a positioning portion is provided near the end of each lead, and the positioning portion of the lead is pressed against the positioning portion of the side surface so that the positioning portion of the lead is positioned on the side surface. It is arranged so that it is arranged on the same plane by the force being pressed against, and the ends of the leads are arranged on the same plane by the positioning portion.

As an advantage of this device, a spring portion is provided adjacent to the positioning portion of each lead, and the positioning portion is pressed against the positioning portion on the side surface by the elastic action of the spring portion. In one embodiment, a recess (recess) is provided on the side surface of the insulating housing, and each lead spring portion is located inside the recess. In the preferred embodiment, each lead is generally U-shaped and includes a first arm and a second arm.
It has an arm and an intermediate part. The first arm is proximate to the first recess surface while the second arm is proximate to the second recess surface and the first and second recess surfaces face each other and the first recess surface is attached. Close to the face. The U-shaped spring portion is formed so that a part of the elongated lead is pushed into the recess when the lead is assembled to the insulating housing.

In order to achieve the third object of the present invention, the terminal is provided with a holding means for fixing to the housing,
The holding means is formed by providing the terminal means with an integral spring portion and further by providing the terminal with a holding portion that cooperates with the insulating housing, and the spring portion presses the holding portion so as to more securely hold the holding portion. There is.

The retaining means is formed by providing at least one channel on one surface of the connector and at least one retaining barb on a portion of the lead. The lead is placed adjacent the channel by bending the lead over the first commandrel. Finally, the barbed portion of the lead is fitted into the channel so that the barb is hooked to secure the lead to the housing. The insulating housing is provided with mating and mounting surfaces, and the housing means are further provided with means for laterally coplanar alignment of the electrical terminals within the housing. The alignment means has a recess formed in a housing means consisting of a flange and two walls orthogonal to the flange. The electrical terminals also include contact portions that connect to corresponding connectors and leads that connect to the surface of the circuit board, with the side edges of the leads of the terminal means engaging the surfaces of the two walls. The lead is provided in the alignment means at an acute angle to the flange, which increases the length of the engagement between the lead and the two walls,
The free ends of the leads can be laterally aligned.
Since the leads are arranged in contact with the flange at an accurate acute angle, the ends of the leads are arranged on the same plane. In the preferred embodiment of the invention, the lead is a spring which is pressed against the lip of the flange.

The electrical component may be an active component such as a transistor or an integrated circuit, or a passive component such as an electrical connector.

(Practical Examples) Next, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows the electrical connector 2 being placed on the mounting surface 4 of the circuit board 6 in an attempt to attach it to the circuit board 6. The illustrated connector is of the general type fully described in U.S. Pat. No. 4,210,376, but is also described here in its entirety for reference. The illustrated connector includes an improved conductor with leads that are particularly suitable for surface mounting to the surface of a circuit board. The description of the general features of the connector is limited to the extent necessary for an understanding of the present invention. The features of the conductors and leads associated with the present invention are described in detail below.

A circuit board conductor 8 is provided on the mounting surface 4 of the circuit board 6,
The end portion is the terminal pad 10. A mounting post 16 integrally provided on the housing 20 of the connector is fitted into a hole or through hole 18 formed in the circuit board.
Lead ends 50 extending from the connector housing 20
In addition, a contact portion 14 that is connected to the terminal pad 10 by soldering is provided. To assemble the connector to the circuit board,
Insert the mounting post 16 into the hole 18 and
Is brought into contact with the terminal pad 10 and lowered from the position shown in FIG. 1 to the positions shown in FIGS. Terminal pad 10
Is covered with a viscous solder alloy material that reflow-melts to join the contact portion 14 and the terminal pad 10.

For successful surface mounting, it is necessary to bring the contact portion 14 into contact with the terminal pad 10 during soldering, and preferably the contact portion is connected to the terminal pad with sufficient force to make good electrical connection during reflow soldering. Be pressed elastically against the pad. Leads that achieve these goals
Structural features of 12 and connector housing 20 will be described in detail below.

As shown in FIG. 1, the insulating housing 20 of the connector 2
Is a mounting surface 22 facing downward in the drawing, a rear side surface 24 extending in a direction orthogonal to the mounting surface, a mating surface 26 (FIG. 4), outer end surfaces 28 facing each other (FIG. 4), and An outer upper wall 30 is provided. Plug housing opening 32 is the mating surface
Formed inward from 26, it is sized to accommodate standard modular plugs of the type used in telephones and other electronic circuits.

The housing 20 contains a plurality of sheet metal conductors 34 formed by stamping, and initially has a lead frame shape as shown in FIG. Each lead frame is provided with the required number of sheet metal conductors 34 for each housing. The conductors 34 are integral at the ends by spaced support strips 38, 40 which, when assembled to the connector housing 20 in the manner described below, are supported from the ends of the conductors. Be separated. As shown in FIG. 5, each conductor 34 includes a spring arm contact portion 42, an intermediate portion 44 disposed in contact with the upper wall 30 of the housing 20, and the lead 12. Each lead is provided with an adjacent portion 46, an intermediate portion 48 and an end portion 50. Adjacent part 46
Adjacent to the side surface 24, the intermediate portion 48 is spring-shaped as described below, and the end portion 50 extends from the outer surface 24 of the housing 20 and is provided with the contact portion 14 at its tip. A portion of the conductor for retaining and fixing it in a shallow channel formed inwardly in the top wall of the housing 20.
The thorns 37 are provided at 44. Further, barbs 84 are provided on the intermediate portion 48 for fastening the terminals to the rear side wall 24. The barbs, as shown in detail in Figure 5A, are easy to insert into the channel but have teeth that, once inserted, secure the terminal within the channel.

As shown in FIG. 9A, a plurality of upright walls 10 are provided from the rear side surface 24.
The zeros extend such that the terminals are housed in upright channels formed therebetween. Raised surface on each wall 10
4 and 106 and recessed surface 108 are provided and will be described in detail below. However, it should be noted that the raised surfaces 104 and 106 of two adjacent walls face each other to form a throttling passage and the recess surfaces 108 face each other to form an enlarged space therebetween.

In addition to the wall 100, first and second flanges 52, 54 extend parallel to the circuit board, spaced apart from the side surface 24 of the housing. Each flange is integrally provided between two adjacent walls 100. First flange 52
Is adjacent to mounting surface 22 while the second flange
54 is located away from the mounting surface 22. 2 apart from each other
The two flanges 52 and 54 and the two walls 100 together form an individual recess 60 between the walls 100. As shown in FIG. 3, each recess 60 has opposed first and second recess surfaces 62, 64, the former adjacent the mounting surface 22 and the latter spaced from the mounting surface 22. First flange 52
A first lip 66 is provided at the inlet end of the second flange 54, while a second lip 68 is provided at the inlet end of the second flange 54. The first and second lips are located at the lower and upper ends of channels formed in the first and second flanges, respectively.

Next, description will be given with reference to FIGS. When assembling the contact conductor 34 to the connector housing 20, separate the support strip 40 from the lead frame and
Bend 42 at a right angle to the middle section 44. Next, the contact portion 42 is fitted downward into the opening 43 provided in the upper wall 30 of the housing 20, and the intermediate portion 44 is fitted into the shallow channel of the upper wall. Then, the lead 21 having the terminal portions 46, 48 and 50 extends rearward from the side surface 24 of the housing 20. The leads are then bent downward to fit the channels between adjacent walls 100 and abut the first and second lips 66,68 of the flanges 52,54, as shown in FIG. Advantageously, when the terminal leads are in the position shown in FIG. 7, the barbs 84 bite into the recessed surfaces 108 (FIG. 9A) of the wall 100 to ultimately secure them prior to the molding step. . The tool 70 is then pressed against the middle portion 48 of the lead, folding those portions within the individual recesses 60. At this time, the second flange 54 functions as a mandrel forming the contact portion 14. When the contact portion 14 is bent along the second lip 68 as shown, a substantially U-shaped spring is formed on each lead. These two flanges cooperate with the tool 70 because the first flange 52 cooperates with the second flange during spring formation.
Can be thought of as a die for performing molding operations in cooperation with.

As shown in FIG. 3, each spring includes a first arm 72 adjacent to the first recess surface 62 and a second arm 72 adjacent to the second recess surface 64.
An arm 74 and an intermediate portion 76 are provided. The second arm 74 of each spring is connected by a transition 78 to a corresponding adjacent lead 46. The portion 80 of each lead that extends from the entrance of the corresponding recess and extends over the first lip 66 serves as a locator that keeps the end 50 of the lead flush.

After retracting the tool, the molded spring will be as shown in FIGS. Large bending of the leads with a tool when forming a U-shaped spring will cause each lead to "spring back", ie, slightly return to its original shape when the tool is retracted. Springback is a phenomenon that occurs when a sheet metal is bent 90 degrees and then released. Because it is a metal temper, when it is bent and then released, it returns slightly to the initial position, so the finished metal bend is not bent 90 degrees. This springback phenomenon is generally regarded as a problem in metal forming, and must be taken into consideration when designing a metal part for punching. In fact, it is due to the springback of the spring portion 46 that the retaining means 84 is provided adjacent the rear side surface 24, as the spring portion 46 tends to return to its original horizontal position.

However, in the present invention, this springback phenomenon is advantageous in the final product because the end portion 50 of each lead 12 is elastically pressed against the first lip portion 66 of the corresponding recess which is the positioning portion. The housing itself is made of molded plastic, so the dimensions are accurate. That is, since the lead positioning portion is pressed against the first lip portion and the first lip portions are accurately aligned with each other, the lead end portion 50 and its contact portion are kept exactly in the same plane.

As is apparent from FIG. 1, the contact portion 14 has a housing 20.
Is located below the mounting surface 22 of. Therefore, when the connector is attached to the circuit board, the ends of the leads bend upward in FIG. Therefore, since the contact portion is elastically pressed against the terminal pad, the contact portion 14 and the terminal pad 10 are sufficiently and uniformly electrically connected.

In addition, the side edges of the terminals engage the raised surfaces 104 and 106 so that the terminals are secured within the channel. The terminals are fixed at two points in the length direction, that is, two raised surfaces 104
And between the two raised surfaces 106. As a result, since the intermediate portion is a spring, the terminal having a long beam length can be sufficiently supported and aligned with the lateral dimension. Furthermore, since the beam portion 80 makes an acute angle with the height direction of the raised surface 106, the long portion of the terminal is aligned and straightened by the squeezing portion formed by the two facing raised surfaces 106. (Fig. 9A) The cooperation of all of the above features allows the contact portions 14 that extend rearwardly and away from the rear side surface 24 of the housing to be accurately aligned and laterally spaced so that the terminal pads 10 on the circuit board. Can be accurately aligned with.

As described above, the second arm 74 of each spring portion is provided with the holding barbs 84 as shown in the figure, and the arm 74 swings while drawing an arc around the lip 68 of the second flange portion when forming the spring. As it moves, the barbs 84 bite into the second side surface 64 of the flange 54 while drawing an arc 86. In other words, when the tool is pushed into the channel and each terminal is pushed into each recess 60, the barbs 84 oscillate in a circular arc to scrape the recessed surface 108 of the wall 100. As described above, when the tool is pressed against the terminals in the recess 60, each molded terminal is formed with a U-shaped spring including the terminal portions 72, 74 and 74.

It should be noted that the metal springback once again has an advantage. Since the spring is located between the two flanges 52 and 54 and the arm 72 of the spring is elastically pressed against the lip 66 of the flange 52, an upward reaction force is exerted on the arm 72, which is transmitted to the arm 74. As a result, the retaining barb is pressed further upwards toward the second recess surface 64. Fortunately, this spring force always pushes the thorn further into the part that has not yet bite into it, as the thorn is pushed further in an arc rather than retracting through the first shaving. The same can be said when the connector is attached to the circuit board, because the reaction force to the contact portion 14 is upward, so that the barbs 84 are made to further dig into the plastic.

As described above, the second lip portion 68 is used as a mandrel for molding the terminal portion 74 into an arc shape. The upper corner 57 of the housing is utilized as a mandrel for molding the terminal portion 46, which requires attention to have a radius larger than the molding radius of the terminal 74. Removal of the terminal from the rear side of the housing would require the terminal portion 46 to be returned along the original swing path. This includes
It may be necessary to allow the barbs 84 to pass through the recessed surface 108 of the wall 100 while scraping. The important thing here is that you have to sharpen the plastic parts that are not yet cut.

As will be appreciated by those knowledgeable in the field of retention mechanisms such as barbs that dig into plastic, to remove the terminals from the rear side 24 of the housing, use a thorn-free solid plastic stick. There will be no need to sharpen. Rather, the barbs 84 scrape the plastic along the first arc path, causing the plastic to flow or channel away. Thus, when the barb is removed from the rear side surface 24 of the housing, the barb 84 will need to scrape away or ride on the plastic forming the flow channel. Further, removal of the terminal would require swaying the terminal portion along an initial path or arc, which would require oscillating the barbs to pass through the raised surface 104.

FIG. 9B shows a modification of the housing with the raised surface 104 'of the wall extending further down into the housing,
When the spine is rocked, the spine bites into the raised surface 104 '.

FIG. 8 shows another embodiment in which the first lip pressing the first arm is an inclined surface 88 rather than an acute edge. This modified example is suitable in some situations.

(Effects of the Invention) As is apparent from the above description, the electric component provided with the surface-mounting type lead according to the present invention can reduce the installation area occupied on the circuit board to which it is attached and reduce the contact portion of the lead. It can be provided on the same plane. The work of assembling the connector conductor (including the lead portion of the conductor) into the connector housing can be performed in a very short time with a relatively simple tool. The present invention can be used in a wide range of electrical components that require surface mounting.
The springs and recesses on each conductor can be of various shapes. An important element of the present invention is the locating surface, or lip, that mates with the spring that presses the end of each conductor against the locating surface. The spring also causes the retaining barb to further dig into the unbroken plastic to secure the terminal within the housing.

Although the preferred embodiment of the present invention is directed to a surface mount connector, the application of the invention is not limited to surface mount connectors. For example, the lead can be used for a through-hole type terminal, and in that case, a cut portion is provided on the side surface of the lead extending downward toward the circuit board. Barbs may be provided on the outer edge of the cut. When fixing the terminal to the housing, the notch but not the entire lead is fitted into the channel in the circular path as described above. The leads are held in a substantially vertical position for through-hole mounting.

[Brief description of drawings]

1 is a cross-sectional view of the connector at a position away from the mounting surface of the circuit board, FIG. 2 is a side view of the connector mounted on the circuit board, and FIG. 3 shows the details of the mounting leads and the leads are in the same plane. FIG. 4 is a perspective view of a connector mounted on a circuit board, FIG. 5 includes a plurality of connector conductors assembled into a connector housing as in FIGS. Fig. 5A is a plan view of the lead frame, Fig. 5A is an enlarged view of a holding barb provided on the terminal, Figs. 6 and 7 are side sectional views of the connector housing for explaining a method of assembling the connector conductor in the connector housing, and Fig. 8 is not included. Third showing an embodiment of
Similar view to FIG. 9, FIG. 9A is an isometric view of the housing showing the internal structure of the housing partially broken away, and FIG. 9B is a view similar to FIG. 9A showing another embodiment of the housing. Is. 2 ... Electrical connector (surface mount type electrical component), 12 ... Lead 14 ... Contact part, 20 ... Insulation housing 52,54 ... Flange, 60 ... Recess 70 ... Tool

Claims (2)

[Claims] 1. An outwardly extending side of the insulating housing,
In a surface mount type electric component having a plurality of leads which are surface mounted on a terminal pad of a circuit board, a plurality of channels formed substantially parallel to each other on a side surface of the insulating housing and connected to the channels. A recess formed inwardly of the insulating housing by a pair of opposed flanges, and a recess disposed in the channel, abutting the flange and curved inwardly of the recess, and a tip of the recess being a contact portion. And a plurality of leads, wherein the contact portions of the leads are substantially flush with each other. 2. The insulating housing extends outward from a side surface,
A method of manufacturing an electric component having a plurality of leads, which are surface-mounted on a terminal pad of a circuit board, wherein a plurality of channels having recesses extending inward are formed between a pair of flanges facing a side surface of the insulating housing. Disposing a plurality of elastic leads having barbs in the channel, engaging the barbs of the leads near one of the flanges, and pressing the leads inwardly of the recess using a tool. The method of manufacturing an electric component, further comprising: extending the tips of the leads to the outside of the insulating housing to form contact portions aligned substantially in the same plane.