JPH06177307A - Outer connection terminals and its lead frame of surface mount semiconductor device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide an external connection terminal of a surface mount semiconductor device capable of improving quality and cost reduction, and a lead frame used for the external connection terminal. [Structure] On a substrate 1 of a semiconductor device on which an electronic component 2 is mounted, each lead pin of an external connection terminal 4 arranged in a line is developed on one lead frame 5 to form a pattern, and each lead pin is formed on the lead frame. Is formed into a U-shape, and the U-shaped bottom surface of the lead pin is used as a solder joint to the mother board, and the leg pieces rising in a bifurcated manner in parallel from both ends of the lead pin are inserted into the lead holes drilled on the board side to form the lead land of the board. After soldering, the tie bar is cut on the lead frame to divide the lead pins into individual pieces. With this configuration, no lead bending process is required for the external connection terminals after mounting on the board, and high-accuracy lead pitch and flatness can be secured for surface mounting on the motherboard.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an external connection terminal of a surface mount semiconductor device such as a hybrid IC and a structure of a lead frame used for the external connection terminal.

[0002]

2. Description of the Related Art As a semiconductor device such as a hybrid IC having a large number of terminals, a surface mount type has been widely adopted instead of a conventional insert mount type as a recent tendency. Next, FIGS. 13 and 14 show examples of conventional structures of external connection terminals applied to the above-mentioned surface mount semiconductor device. In each figure, 1 is a substrate of a semiconductor device, 2 is an electronic component such as a semiconductor chip mounted on the substrate 1, and 3 is a substrate 1.
The external connection terminals are arranged on the peripheral portion of the. Here, FIG.
The external connection terminal 3 shown in FIG. 3 is a clip-type terminal called an F-type lead, and the clip portions of the lead pins that are arranged in a row and pattern-formed on the lead frame are mounted on the substrate 1 and soldered to the lead lands of the conductor pattern. After doing
In order to be compatible with surface mounting, an L-shaped bending process is applied to the tip of the lead terminal to form a flat solder joint 3a (soldering part when mounting on a motherboard).
Further, the external connection terminal 3 shown in FIG. 14 is called a wrapping terminal, and a plurality of reaping pins arranged in a line is previously integrally molded on the pedestal 3b of the resin molded product, and the pedestal 3b is provided on the bottom side of the pedestal 3b. Shows the soldering portion 3a which is previously bent and formed. When the lapping terminal is attached to the substrate 1, the tips of the lead pins protruding from the upper surface of the pedestal 3a are inserted into the lead holes formed in the substrate 1 from the back surface side and soldered to the lead lands of the conductor pattern. 1
The base and the pedestal 3b are fixed with an adhesive.

[0003]

By the way, the above-mentioned conventional external connection terminal has the following drawbacks. (1) In the clip-shaped external connection terminal shown in FIG. 13, after the external connection terminal 3 is attached to the substrate 1 on which electronic components are mounted, each lead pin of the external connection terminal is lead-bent processed into an L-shape. Forming work is difficult.
Further, since each lead pin is fixed to the substrate 1 in a cantilever manner, a warp occurs due to a springback phenomenon that occurs after the lead bending process, resulting in variations in the pitch accuracy of the lead pins and the flatness of the soldered portion 3a. As a result, the soldering parts of each lead pin become uneven, and when mounting on a motherboard (usually using the reflow soldering method), problems such as solder bridges and poor soldering due to lifting of the tip of the lead pin occur. This is the cause of lowering the non-defective product rate.

(2) While the lapping terminal shown in FIG. 14 is more stable in lead pitch accuracy and flatness than the terminal structure shown in FIG. 13, mold equipment is required to manufacture the pedestal 3b as a resin molded product. Therefore, the cost is high. The present invention has been made in view of the above points, and an object thereof is to solve the above problems and to provide an external connection terminal of a surface mount semiconductor device capable of improving quality and cost reduction, and a lead frame used for the external connection terminal. To provide.

[0005]

In order to achieve the above-mentioned object, the external connection terminal of the present invention has each individual lead pin U.
A solder joint portion when the bottom surface of the lead pin corresponding to the bottom of the U-shape is mounted on the motherboard, and the forked leg pieces rising from both ends of the solder joint portion are used as the board insertion portion, and the leg piece is used. It is configured to be fixed and connected by being inserted into a lead hole drilled in the substrate of the semiconductor device.

Further, as a concrete embodiment of the above-mentioned external connection terminal, there is a configuration as described below. (1) A plurality of lead pins arranged at regular pitches are developed on one lead frame to form a pattern, and each lead pin is formed into a predetermined shape and then inserted and connected to a substrate of a semiconductor device all at once. Then, the lead frame is further cut by tie bars to divide the lead pins into individual pieces.

(2) A standoff for insertion and positioning is provided on the leg piece of the lead pin. (3) As a means for preventing the lead pins inserted into the board from falling off, the leg pieces of the lead pins are preliminarily provided with an inclination angle in either the inside or outside direction. (4) As a means for preventing the lead pin inserted into the board from falling off, a leg portion of the lead pin is provided with a retaining claw portion.

(5) An extension piece portion, which is continuous with the solder joint portion of the U-shaped lead pin and extends outward from the peripheral area of the substrate of the semiconductor device, is provided. On the other hand, the lead frame of the present invention used for assembling the external connection terminal having the above-described structure is formed by developing a plurality of lead pins arranged at regular pitches and a tie bar interconnecting the lead pins into a single metal ribbon. Then, a pattern is formed.

Further, as a concrete embodiment of the lead frame, there is the following structure. (1) In the lead pin portion of the lead frame, a pair of leg pieces corresponding to the bifurcated board insertion portion of the external connection terminal are developed in opposite directions to form patterns on both sides of the portion corresponding to the solder joint portion.

(2) In the lead pin portion of the lead frame, a pair of leg pieces corresponding to the bifurcated board insertion portion of the external connection terminal are developed in the same direction to form patterns on both sides of the portion corresponding to the solder joint portion. To do. (3) A notch for tie bar cutting is formed at the boundary between the tie bar and the lead pin connected to the tie bar.

(4) The tongue piece corresponding to the extension piece portion of the external connection terminal is formed in a pattern by connecting to the portion corresponding to the solder joint portion of the lead pin.

[0012]

The above-mentioned external connection terminals are formed in a U-shape with the lead pitch and flatness of each lead pin being made uniform before the lead frame is manufactured before being mounted on the substrate of the semiconductor device. This lead frame is mounted on the substrate. After doing
No lead processing is required other than tie bar cutting.
Therefore, the lead pitch accuracy and flatness are stable, and the mounting work on the substrate can be performed easily. Moreover, since each lead pin is fixedly supported at two positions on both ends of the board, it can be mounted on the surface of the motherboard while maintaining a stable standing posture.

Further, the standoff provided on the leg piece of the lead pin functions as a positioning member when the lead pin is inserted into the lead hole of the substrate. In addition, insert the lead pin into the lead hole of the board by setting the inclination angle to the leg pin of the lead pin in advance either inward or outward, or by providing the leg pin leg with a retaining tab. In this state, the lead terminals are prevented from moving from their proper insertion positions and falling off.

Further, the extension piece portion which is connected to the solder joint portion (U-shaped bottom side) of the U-shaped lead pin so as to project outward from the substrate peripheral region of the semiconductor device functions as follows. That is, when the semiconductor device is mounted on the motherboard, and the circuit assembly is visually inspected from above or with an optical device to confirm the soldering state between the motherboard and the external connection terminal, the extension piece is used. In the external connection terminal having no part, the state of the soldered part is hidden behind the substrate of the semiconductor device and cannot be recognized. In this regard, if an extension piece is provided at the solder joint of the external connection terminal, the tip of the extension piece soldered to the mother board can be seen from above without being obstructed by the board, and thus the soldered state The quality of can be confirmed accurately.

On the other hand, on the lead frame, a pair of leg pieces corresponding to the board insertion portion of the lead pin are developed in opposite directions to form patterns on both sides of the portion corresponding to the solder joint portion. Then, the leg pins are formed into a U shape by bending and forming the leg pieces in the same direction, and the bottom surface of the U shape is used as a solder joint. On the other hand, in the case where the pair of leg pieces corresponding to the board insertion portion of the lead pin are developed in the same direction and pattern-formed on both sides of the portion corresponding to the solder joint, the bending forming process as described above is performed. Instead, the cut section (side edge) of the U-shaped bottom of the lead pin is used as the solder joint.

Further, by forming a notch for tie bar cutting at the boundary between the tie bar and the lead pin connected to the tie bar, the tie bar cutting performed after the lead frame is mounted on the substrate can be easily performed.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. 1A is a top view of a semiconductor device in which the external connection terminals 4 are mounted on the substrate 1, FIG. 1B is a back view, and FIG. 1C shows a state in which the lead frame 5 of the external connection terminals 4 is mounted on the substrate 1. It is a figure. Here, the external connection terminals 4 mounted side by side in a row on the substrate 1 on which the electronic component 2 is mounted are mounted as shown in FIG.
Each lead pin is formed into a U-shape as shown in FIG. 3, and the bottom of its center is the solder joint 4a, and a pair of legs rising in a bifurcated manner from both ends thereof are the board insertion portions 4b and 4c. A lead hole 1 in which a pair of leg pieces are drilled in the substrate 1 so that 4a projects to the back side of the substrate 1.
a (round hole or square hole) and solder it between the board side conductor pattern (lead land) 1b to fix it.
It is connected. The depth of insertion into the substrate 1 is regulated by the standoff portion 4d formed on the leg piece of the substrate joint portion. When the semiconductor device is mounted on the motherboard 6, the solder joint portion 4a of the U-shaped external connection terminal 4 is mounted on the conductor pattern 6a of the mating mother board 6,
Surface mount by reflow soldering method.

Next, an example of a lead frame used for the external connection terminal 4 is shown in FIG. (A) is a pattern development view of the lead frame 5, (b) is a plan view in which lead pins are bent on the lead frame, and (c) is a perspective view of (b). Frame for example thickness
The phosphor bronze hoop material having a thickness of 0.3 to 0.5 mm is used as a material and is made by press working, etching working, laser working, etc., and its surface is solder-plated. Here, the lead frame 5 has a plurality of lead pins 5a arranged in a line (corresponding to the external connection terminals 4 in FIG. 2),
Tie bar 5b interconnecting lead pieces 5a, branch strips of tie bar 5c, lead frame feed pitch hole 5
d, and notches 5e and standoffs 5e (corresponding to the standoff portion 4d in FIG. 2) cut and formed in the portions to be subjected to the aver cut are patterned as illustrated. In addition, as shown in FIG.
As a development pattern of the lead pin 5a, a pair of leg pieces 5a-corresponding to the pair of board insertion portions 4b and 4c described in FIG.
Patterns 1 and 5a -2 are formed on both sides of the portion 5a-3 corresponding to the solder joint 4a and are developed in opposite directions.

Then, with respect to the lead frame 5 patterned as shown in (a), the lead pins 5a of each strip are bent at right angles at dotted points P and Q to form a U shape, and (b) and (c) are formed. ) Obtain the shape of the lead frame shown in the figure. Next, the lead frame 5 is attached to the substrate 1 as shown in FIG.
After the leg pieces 5a-1 and 5a-2 of the lead pins 5a, which are bifurcated, are inserted into the lead holes 1a and soldered between the board and the lead pins, the notches 5e of the lead frame 5 are formed. The lead pin 5
The external connection terminal 4 shown in FIG. 2 is obtained by dividing a into individual pieces.

Next, application examples of the lead frame 5 shown in FIG. 3 are shown in FIGS. First, FIG. 4 (a)-
(C) is an application pattern example of the lead pin 5a,
In the figure, (a) shows a pattern in which the central portion of the lead pin 5a is wider than that in FIG. 3 to increase the area of the solder joint,
(B) In the figure, one leg piece 5a-1 is divided into two forks, and the insertion portion to the board is made into a total of three legs to further stabilize the mounting posture of the external connection terminal. (C) Figure is 2
A standoff 5f is formed for each of the leg pieces 5a-1 and 5a-2 of the book so as to stabilize the insertion posture to the substrate.

FIG. 5 shows the lead pin 5a of the lead frame 5.
With the lead pin 5a inserted in the lead hole 1a of the substrate 1, the lead pin insertion position is displaced downward due to the weight of the lead frame, or the leg pin of the lead pin 5a is used as a fall-out preventing means for preventing the leg piece of the lead pin from coming out of the lead hole. Piece 5
An example in which bending angles are given to a-1 and 5a-2 in advance will be shown. That is, in FIG. 5A, when the lead pin 5a is formed into a U shape, the bifurcated leg pieces 5a-1 and 5a are formed.
-The bending angle is given by bending locally so that the tip part of -2 spreads in an inverted "C" shape. Also,
In the diagram (b), one leg piece 5a -2 is bent to be slightly shallower than a right angle, and an inclination angle θ is given to the remaining leg piece 5a-1. By thus preliminarily imparting the inclination angle θ to the leg pieces of the lead pin, when the lead pin is inserted into the lead hole 1c of the substrate 1 as shown in FIG.
A pressing force due to spring elasticity of the leg pieces acts between the leg pieces 5a-1 and 5a-2 and the lead hole 1a, and this pressing force works as a resistance force for preventing the lead pin from coming off. In addition, in the illustrated example, the inclination angle θ of the lead pin is shown as an example in which the leg pieces 5a-1 and 5a-2 facing each other are provided in the direction of opening outward, but the same effect can be obtained even if they are provided in the direction of closing inward. can get.

FIGS. 6 (a) to 6 (c) show, as means for preventing the lead pin from falling off, an engaging claw portion 5g protruding laterally at the tip portion of the leg pieces 5a-1 and 5a-2. is there. Note that 5h is a recess for temporarily releasing the claw portion 5g when the leg piece is inserted into the lead hole 1a of the substrate 1. In this way, by forming the engaging claw portion 5g at the tips of the leg pieces 5a-1 and 5a-2, the lead pin 5a is attached to the substrate 1 as shown in FIG.
When press-fitting into the lead hole 1a from below, the claw portion 5g is caught on the upper surface of the substrate 1 at a position where it penetrates the lead hole, and the lead pin is locked and held at a predetermined insertion position. Therefore, the lead pin is surely prevented from slipping out of the insertion position or coming off.

Further, FIG. 7 shows an application example of FIG. 6, and is slightly outside the diameter of the lead hole 1a on both sides of the tip portion with respect to the leg pieces 5a-1 and 5a-2 of the lead pin 5a. A wedge-shaped engaging claw portion 5g protruding toward one side is formed, and the substrate 1
When the lead pin 5a is press-fitted into the lead hole 1a from the direction of the arrow, the claw portions 5g on both sides are caught by the substrate 1. Next, FIGS. 8 and 9 show an embodiment of a lead frame different from that of FIG. That is, in this embodiment, with respect to the pattern of the lead pin 5a in the lead frame 5, the pair of left and right leg pieces 5a-1 and 5a-2 are arranged in the same direction and are developed so as to form a U shape as a whole. Moreover, in FIG.
-1 and 5a -2 are formed in a zigzag shape so that they are parallel to each other with the front and rear shifted. On the other hand, FIG.
In this case, the leg pieces 5a-1 and 5a-2 are formed side by side on the same surface without forming. In this embodiment, the side edge (cut surface of the conductor) of the U-shaped bottom portion 5a-3 serves as a solder joint surface for the mother board. The mounting method on the substrate 1 and the mounting and soldering method on the mother board are performed in the same manner as the lead frame shown in FIG.

In this way, the leg pieces 5a-1 and 5a-2 are aligned in the same direction and the lead pin 5a is developed on the lead frame 5 to form a U-shaped pattern, which is different from the lead frame of FIG. The overall width W can be short, the amount of wasteful scrap produced when the lead frame 5 is manufactured is small, and the material cost can be reduced. It should be noted that this embodiment is effective when the pitch of the lead holes drilled in the substrate of the semiconductor device is relatively large because the pair of leg pieces are arranged on the left and right.

On the other hand, FIG. 10 shows U described in each of the above embodiments.
This shows an assembled state in which the external connection terminals 4 having a letter shape are mounted on the substrate 1 of the semiconductor device and assembled, and then mounted on the motherboard 7 and joined by solder reflow or the like. In the figure, 7 is a separate component arranged on the substrate 1 and mounted on the mother board 6, and 8 is a solder joint 4a of the external connection terminal 4.
Figure 3 shows a solder joint between a soldering land on the motherboard (see Figure 2).

By the way, with the assembly structure shown in FIG. 10 as it is, the product inspection step following the assembly step, especially the mother board 6 and the external connection terminals 4 of the semiconductor device mounted therein are carried out.
When inspecting the soldering condition between and, the following problems occur. That is, in this soldering inspection process,
The circuit assembly of FIG. 10 is visually inspected by an inspector from above or by using an optical device 9 to judge whether the soldering condition of the solder joint 8 is good or bad. However,
In this case, when the board 1 and the separate component 7 are close to each other on the mother board 6 as shown in the figure, the solder joint portion 8 between the external connection terminal 4 and the mother board 6 is hidden behind the board 1. In addition, the separate component 7 is obscured from the oblique side and is difficult to see, and when the optical device 9 is used, the solder joint 8
Cannot be recognized because it is not in the field of view.

Therefore, the embodiment shown in FIG. 11 is a modification of the external connection terminal 4 in order to solve such a problem. That is, in this embodiment, the U-shaped external connection terminal 4 mounted on the substrate 1 is provided with the extension piece portion 4e that laterally projects so as to project from the bottom portion thereof toward the outside of the region of the substrate 1. There is. Such an extension piece 4
By adopting the external connection terminal 4 integrally formed with e, in the inspection process performed after mounting on the mother board 6,
Solder joint 8 between the external connection terminal 4 and the mother board 6
The soldering condition (solder fillet) is different from the board 1
It can be accurately recognized by the optical device 9 arranged above through the gap between the and. Further, by providing the extension piece 4e, the solder joint area between the external connection terminal 4 and the motherboard 6 is increased, and the joint strength and the mounting posture of the semiconductor device are further stabilized.

Next, FIG. 12 shows a lead frame for manufacturing the external connection terminal 4 having the extension piece 4e. Here, (a) is a developed view of the lead pin 5a formed by patterning on the lead frame 5, and (b) shows a state after the lead bending process is applied to the lead pin portion of the lead frame 5. First, in the development view of FIG. 3 (a), in addition to the pattern shown in FIG. 3 (a) described above, a tongue piece developed so as to extend in parallel with the leg piece 5a-2 in connection with the bottom portion 5a-3. 5a-4 is patterned. And
This lead pin 5a is formed into a U-shape as shown in FIG. 2B, and then leg pieces 5a-1 of the lead pins arranged in line are formed.
The branch piece 5c of the tie bar is cut while 5a-2 is attached to the lead hole of the substrate 1 to finish the state shown in FIG. The length dimension a of the tongue piece 5a-4 in FIG. 12 (a) is selected such that at least the tip of the tongue piece protrudes laterally beyond the peripheral edge of the substrate 1 as shown in FIG. 12 (b). ,
In actual design, the a dimension is designed to be about 1 to 2 mm.

[0029]

The present invention has the following effects because the external connection terminals of the surface-mounted semiconductor device and the lead frame thereof are configured as described above. (1) Since the lead pins are formed into U-shapes in advance on the external connection terminals to be mounted on the substrate of the semiconductor device to form the flat soldering portions corresponding to the surface mounting, the lead bending process is performed after mounting on the substrate. It is not necessary at all, and the product assembly process can be rationalized. In addition, the U-shaped lead pin is supported on the board by two points on each piece via a pair of leg pieces, so the support strength is high and a stable posture. Can be securely mounted on the motherboard.

(2) Further, since a plurality of lead pins arranged in a line are patterned on one lead frame to form the external connection terminal, the external connection terminal can be manufactured at a lower cost than the conventional lapping terminal. The lead pin pitch accuracy and flatness are stable, and the quality can be improved. (3) In addition, by providing standoffs to the leg pieces of the lead pins, the depth of insertion into the board can be defined, and by providing an inclination angle and forming engaging claws,
It is possible to reliably prevent the lead pin insertion position from slipping off or falling off when it is inserted into the board.In addition, by forming a notch at the boundary between the tie bar of the lead frame and the lead pin, tie bar cutting can be done easily. Benefits are obtained.

(4) Further, the semiconductor device is formed by previously forming an extension piece extending from the solder joint on the bottom of the U-shaped external connection terminal so as to protrude outside the area of the substrate. When the product is inspected after it is mounted on the motherboard, the soldering state between the external connection terminals and the motherboard can be visually checked from above without being obstructed by the substrate of the semiconductor device, or easily checked by an optical device. The quality can be determined, and the quality inspection process can be simplified.

[Brief description of drawings]

1A and 1B are external perspective views showing the entire configuration of an embodiment of the present invention, where FIG. 1A is a top view of a semiconductor device substrate with external connection terminals attached, FIG. 1B is a back view, and FIG. Diagram showing the state where the lead frame of the external connection terminal is attached to the circuit board

2A and 2B are enlarged views of the structure of the external connection terminal in FIG. 1, in which FIG. 2A is a side view and FIG. 2B is a front view.

3A and 3B are views showing a lead frame used for the external connection terminal of FIG. 1, FIG. 3A is a pattern development view, and FIG. 3B is a plan view showing a state where a lead pin is formed into a U shape.
(C) is an external perspective view of (b)

FIG. 4 is a diagram showing a configuration of a lead frame showing an application example of FIG. 3, and (a), (b), and (c) are pattern development diagrams of different examples.

FIG. 5 is a configuration diagram of an embodiment in which a leg piece is provided with an inclination angle as a lead pin retaining means of the present invention.
(B) is a side view of lead pins of different embodiments,
(C) is a diagram of the lead pin insertion into the board

6A and 6B are configuration diagrams of an embodiment in which an engaging claw portion is formed on a leg piece as a lead pin removal preventing means of the present invention, FIG. 6A is a pattern development view of a lead pin, and FIG. 6B is a main part of FIG. Enlarged view, (c) is a diagram showing how lead pins are inserted into the board

FIG. 7 is a diagram of the tip shape of the lead pin showing the application example of FIG.

8A and 8B are configuration diagrams of a lead frame of an embodiment different from FIG. 3, in which FIG. 8A is a front view, FIG. 8B is a side view, and FIG.

9A and 9B are configuration diagrams of a lead frame showing an application example of FIG. 9, in which FIG. 9A is a front view and FIG. 9B is a side view.

FIG. 10 is a mounting state diagram of a semiconductor device adopting the external connection terminal of FIG. 2 on a motherboard.

FIG. 11 is a mounting state diagram of a semiconductor device adopting an external connection terminal of an application example different from that of FIG. 2 on a motherboard.

12A and 12B are configuration diagrams of a lead frame corresponding to the external connection terminal adopted in FIG. 11, FIG. 12A is a pattern development view of a lead pin portion, and FIG. 12B is a side view of the lead pin in a formed state.

FIG. 13 is an external perspective view showing a configuration of an external connection terminal (F-type lead terminal) of a conventional surface mount semiconductor device.

FIG. 14 is an external perspective view showing the configuration of a conventional external connection terminal (lapping terminal) different from FIG.

[Explanation of symbols]

 1 Board 1a Lead Hole 2 Electronic Component 4 External Connection Terminal 4a Solder Joint 4b Board Insertion Part 4c Board Insertion Part 4d Standoff 4e Extension Piece 5 Leadframe 5a Lead Pin 5a-1 Leg 5a-2 Leg 5a-4 Tongue Piece 5b Tie bar 5d Tie bar cut notch 5f Standoff 5g Engaging claw 5θ Inclination angle

Claims (11)

[Claims] 1. A lead pin which is an external connection terminal of a surface mount type semiconductor device having a large number of terminals for a hybrid IC or the like, wherein each individual piece of the lead pin is formed in a U-shape, and which corresponds to the bottom of the U-shape. Solder joint when mounting the bottom surface of the to the motherboard, the forked leg that rises from both ends of the solder joint is used as the board insertion portion, and the leg is inserted into the lead hole drilled in the substrate of the semiconductor device and fixed, An external connection terminal of a surface-mounted semiconductor device characterized by being connected. 2. The external connection terminal according to claim 1, wherein a plurality of lead pins arranged at regular pitches are developed on one lead frame to form a pattern, and each lead pin is formed into a predetermined shape. An external connection terminal for a surface-mount type semiconductor device, characterized in that the lead frame is divided into individual pieces by collectively inserting and connecting to the substrate of the semiconductor device and cutting the lead frame with a tie bar. 3. The external connection terminal according to claim 1, wherein the leg piece of the lead pin is provided with a standoff for insertion and positioning. 4. The external connection terminal according to claim 1, wherein the leg pins of the lead pin are preliminarily provided with an inclination angle in either the inside or outside direction as a means for preventing the lead pin inserted into the board from falling off. External connection terminals for surface mount semiconductor devices. 5. The surface-mounting semiconductor device according to claim 1, wherein a leg portion of the lead pin is provided with a retaining tab for preventing the lead pin inserted into the substrate from coming off. External connection terminal. 6. The external connection terminal according to claim 1, wherein U
An external connection terminal for a surface-mounted semiconductor device, characterized in that an extension piece portion, which is connected to the solder joint portion of the V-shaped lead pin and extends outward from the peripheral area of the substrate of the semiconductor device, is provided. 7. The pattern according to claim 2, wherein a plurality of lead pins arranged at regular pitches and a tie bar interconnecting the lead pins are spread on one metal ribbon to form a pattern. Lead frame used for external connection terminals. 8. The lead frame according to claim 7,
The lead pin portion of the lead frame is characterized in that a pair of leg pieces corresponding to the bifurcated board insertion portion of the external connection terminal are developed in opposite directions to form patterns on both sides of a portion corresponding to the solder joint portion. Lead frames used for external connection terminals of surface mount semiconductor devices. 9. The lead frame according to claim 7,
A surface mount characterized in that a pair of leg pieces corresponding to the board insertion portion of the external connection terminal are developed in the same direction on the lead pin portion of the lead frame and pattern-formed on both sides of the portion corresponding to the solder joint portion. Type lead frame used for external connection terminals of semiconductor devices. 10. The lead frame used in an external connection terminal of a surface mount semiconductor device according to claim 7, wherein a notch for cutting a tie bar is formed at a boundary between the tie bar and a lead pin connected to the tie bar. . 11. The lead frame according to claim 7, wherein a tongue piece corresponding to the extension piece portion of the external lead-out terminal is connected to a portion corresponding to the solder joint portion of the lead pin to form a pattern. Lead frames used for external connection terminals of semiconductor devices.