JP2012069563A - Lead frame, method of manufacturing the same, and manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lead frame, a method of manufacturing the same and a manufacturing apparatus, capable of preventing occurrence of a short circuit between leads due to whisker, without degrading a yield.SOLUTION: A lead frame 10 includes a sealing resin part 12 where a semiconductor chip 20 is arranged, and a plurality of leads 11 protruding sideways from the sealing resin part 12. The lead 11 includes tie bar cut traces 14a and 14b in which a tie bar 13, which extends in the direction perpendicular to the length direction of the lead for connecting adjoining leads together, is punched out for cutting, diagonally against the length direction of the lead, with an end part formed to be a tapered shape. Relating to the tie bar cut traces 14a and 14b, W/D<w/d is established, where W is width of the tie bar, d is distance between straight lines L1 and L2, D is distance in tie bar length direction from a taper tip part 14at to a taper root part 14ar, and w is distance on a straight line L2 from an intersection P1 between a straight line L3 and the straight line L2 to an intersection P2 between a line segment S and the straight line L2.

Description

  The present invention relates to a lead frame used in a semiconductor device such as an IC (semiconductor integrated circuit) or an LSI (large scale integrated circuit), a manufacturing method thereof, and a manufacturing apparatus. More specifically, the present invention relates to a lead frame capable of preventing a short circuit between leads due to whiskers, a manufacturing method thereof, and a manufacturing apparatus.

  On the lead of the resin-encapsulated semiconductor device, exterior plating is formed in order to obtain good solderability and good connection reliability when joining with an external device. In recent years, since it is required not to use lead that adversely affects the human body, lead-free solder may be used for exterior plating. In addition, lead-free solder is used as the solder for joining the lead of the semiconductor device onto the land of the circuit board.

  In recent years, with high density mounting, a large number of leads are provided in a semiconductor device at very narrow intervals. For this reason, when the leads of the semiconductor device are soldered and fixed onto the lands of the circuit board, there is a problem that excessive solder enters between the leads and a solder bridge is generated between adjacent leads. In particular, solder bridges were likely to occur at tie bar cut traces where the distance between leads was narrow.

  Therefore, in order to prevent the occurrence of solder bridges at the tie bar cut trace, a plurality of tie bars are provided to be inclined with respect to the width direction of the lead terminals, and the lead terminal connection position and the other end of one end of the tie bar There has been proposed a lead frame in which the inclination angle of the tie bar is set so that the lead terminal connection position does not overlap when viewed from the width direction of the lead terminal (see Patent Document 1). As a result, the interval between the lead terminals of the tie bar cut trace portion is made wider than that of the conventional one to prevent the occurrence of solder bridges at the tie bar cut trace portion.

JP 2005-183695 A

  However, when the tie bars are provided obliquely as described above, there is a problem that the yield deteriorates. In addition, when soldering the lead terminal to the circuit board including the above-described technology, if solder that spreads thinly like plating is used, whiskers may occur. Whisker is generated and grows when stress is generated in a thin part of solder or plating. Here, the tie bar cut trace portion of the lead generates residual stress during cutting and clinching. Therefore, if the solder wets the lead and thins, the whisker is likely to be generated. And when a whisker occurs in the tie bar cut trace part, it grows toward the tie bar cut trace part of the adjacent lead, and finally, the tie bar cut trace part of the adjacent lead is connected by the whisker, resulting in a short circuit between the leads. There was a problem that.

  Accordingly, the present invention has been made to solve the above-described problems, and provides a lead frame that can prevent a short circuit between leads due to whiskers without deteriorating the yield, and a manufacturing method and a manufacturing apparatus thereof. For the purpose.

  One embodiment of the present invention made to solve the above problems includes a sealing resin portion in which a semiconductor element is disposed, and a plurality of portions that are electrically connected to the semiconductor element and protrude laterally from the sealing resin portion. In the lead frame including the lead, the lead extends in a direction perpendicular to the longitudinal direction thereof, and tie bars for connecting adjacent leads are punched and cut obliquely (tie bar cut) with respect to the longitudinal direction of the leads. Each tie bar cut trace portion formed between the adjacent leads has a tie bar width W on the lead surface, and the tie bar cut trace portion of the tie bar cut trace portion The distance between the straight lines L1 and L2 parallel to the lead passing through each taper tip is d, and the distance in the tie bar longitudinal direction from one taper tip to the taper root is D, A straight line extending from the intersection of the straight line L2 and the straight line L2 passing through the taper tip of the direction and perpendicular to the taper part to the intersection of the straight line L2 and the line segment connecting the taper tip to the other taper root When the distance on L2 is w, the relationship of W / D <w / d is satisfied.

  In this lead frame, on the lead surface, in other words, in a plan view ignoring the thickness of the lead, the width of the tie bar (tie bar cut trace) is W, the distance between the straight lines L1 and L2 is d, and one taper is formed. The distance in the longitudinal direction of the tie bar from the tip to the taper root is D, and the straight line from the intersection of the straight line L3 and the straight line L2 to the intersection of the line segment connecting the taper tip to the other taper root and the straight line L2. When the distance on L2 is set to w, each tie bar cut that remains between adjacent leads is tie bar cut obliquely with respect to the longitudinal direction of the lead so as to satisfy the relationship of W / D <w / d. The end of the trace is formed in a taper shape. Therefore, when soldering the tip of the lead to the circuit board, even if a whisker is generated and grows from the end of one tie bar cut trace, the other tie bar cut trace does not contact (reach). This is because whiskers that cause a short circuit between adjacent leads grow almost vertically. As a result, the tie bar cut traces of adjacent leads are not connected by the whisker, so that it is possible to prevent a short circuit between the leads due to the whisker.

  In this lead frame, a tie bar formed so as to extend in a direction perpendicular to the longitudinal direction of the lead is punched and cut. Therefore, the yield does not deteriorate as in the case where the tie bars are provided obliquely.

  In the lead frame described above, it is desirable that a plating removal portion is formed on the lead between the tip end and the tie bar cut trace portion by removing the plating on the lead surface.

  Thus, since the plating removal part is formed in the lead, the solder does not get wet in the plating removal part, so that the solder removal in the plating removal part can be stopped. Since the plating removal portion is provided between the lead tip and the tie bar cut trace portion, the solder does not reach the tie bar cut trace portion. Therefore, the generation of whiskers at the tie bar cut trace can be suppressed. Thereby, the occurrence of a short circuit between the leads due to the whisker can be more reliably prevented.

  In the lead frame described above, a recess may be formed in the lead between the tip and the tie bar cut trace.

Thus, a thick solder layer is formed on the lead by forming the recess between the lead tip and the tie bar cut trace. That is, a thin solder layer is not formed on the lead. Thereby, generation | occurrence | production of a whisker can be suppressed. Therefore, it is possible to more reliably prevent the occurrence of a short circuit between the leads due to the whisker.
In addition, a recessed part may be provided independently and may be provided with the plating removal part.

  The lead frame described above can be realized by performing the following manufacturing method. That is, in the lead frame manufacturing method comprising: a sealing resin portion in which a semiconductor element is disposed; and a plurality of leads that are electrically connected to the semiconductor element and project laterally from the sealing resin portion. Each tie bar cut trace portion remaining between the adjacent leads is formed by cutting a tie bar extending in a direction perpendicular to the longitudinal direction of the lead and connecting adjacent leads obliquely with respect to the longitudinal direction of the lead (tie bar cut). When the end portion of the tie bar is formed in a tapered shape, the width of the tie bar is W on the surface of the lead and parallel to the lead passing through the taper tip of each tie bar cut mark portion remaining after the tie bar cut between adjacent leads. The distance between the straight lines L1 and L2 is d, the distance in the longitudinal direction of the tie bar from one taper tip to the taper root is D, and passes through one taper tip. The distance on the straight line L2 from the intersection of the straight line L3 and the straight line L2 to the intersection of the straight line L2 and the line segment connecting one taper tip to the other taper root is w As long as the relationship of W / D <w / d is satisfied.

  In the lead frame manufacturing method described above, at least one of a plating removal part or a concave part from which the plating of the lead surface has been removed may be formed between the tip of the lead and the trace part of the tie bar.

  The lead frame described above can be realized by using the following manufacturing apparatus. That is, in the lead frame manufacturing apparatus comprising: a sealing resin portion in which a semiconductor element is disposed; and a plurality of leads electrically connected to the semiconductor element and projecting laterally from the sealing resin portion. Each tie bar cut trace portion remaining between the adjacent leads is formed by cutting a tie bar extending in a direction perpendicular to the longitudinal direction of the lead and connecting adjacent leads obliquely with respect to the longitudinal direction of the lead (tie bar cut). A tie bar cutting jig that forms an end of each tie bar cut jig, wherein the tie bar cutting jig has a width of the tie bar on the lead surface, and each tie bar cut trace portion remaining between adjacent leads. The distance between the straight lines L1 and L2 parallel to the lead passing through the taper tip is d, and the distance in the tie bar longitudinal direction from one taper tip to the taper root is shown. , From the intersection of the straight line L2 and the straight line L2, which passes through the one taper tip and is orthogonal to the taper part, to the intersection of the straight line L2 and the line segment connecting the one taper tip to the other taper base The distance on the straight line L2 is w, and the cross-sectional shape for performing the tie bar cut may be provided with a parallelogram-shaped cutting blade so as to satisfy the relationship of W / D <w / d.

  According to the lead frame, the manufacturing method, and the manufacturing apparatus according to the present invention, as described above, it is possible to prevent a short circuit between leads due to whiskers without deteriorating the yield.

It is a figure which shows schematic structure of the lead frame which concerns on 1st Embodiment. It is sectional drawing of a sealing resin part. It is an enlarged view of a tie bar cut trace part between adjacent leads. It is a figure which shows the lead frame before a process (tie bar cut). It is a figure which shows schematic structure of a tie bar cut punch. It is sectional drawing of the cutting blade with which a tie bar cut punch is equipped. It is a figure which shows schematic structure of a tie bar cut die. It is a figure which shows the state which soldered the front-end | tip of a lead to the circuit board. It is a figure which shows schematic structure of the lead frame which concerns on 2nd Embodiment. It is a figure which shows schematic structure of the lead frame which concerns on 3rd Embodiment.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying a lead frame, a manufacturing method and a manufacturing apparatus according to the present invention will be described below in detail with reference to the drawings.

[First Embodiment]
First, the first embodiment will be described. Therefore, the lead frame according to the first embodiment will be described with reference to FIGS. FIG. 1 is a diagram showing a schematic configuration of a lead frame according to the first embodiment. FIG. 2 is a cross-sectional view of the sealing resin portion. FIG. 3 is an enlarged view of a tie bar cut trace portion between adjacent leads. FIG. 4 is a view showing the lead frame before processing (tie bar cutting).

  As shown in FIG. 1, the lead frame 10 includes a plurality of leads 11. A plurality of these leads 11 protrude laterally from the sealing resin portion 12. And the lead 11 is provided with the tie bar cut trace 14 which is the part which the tie bar 13 (refer FIG. 4) which connected adjacent leads was punched and cut and remained. The tie bar cut traces 14 are positioned so as to face each other between adjacent leads. In the present embodiment, the width of the lead 11 is 0.5 mm, the interval between the leads is 0.77 mm, and the width of the tie bar cut mark portion 14 (tie bar 13) is 0.15 mm.

  As shown in FIG. 2, a semiconductor chip 20 is provided in the sealing resin portion 12. The semiconductor chip 20 is mounted on a die pad 21 that is a part of the lead frame 10. The electrodes provided in the semiconductor chip 20 are wire bonded to the leads 11 with metal wires 22. Thus, the semiconductor chip 20 and the lead 11 are electrically connected via the metal wire 22.

  Here, the tie bar cut trace portion 14 between adjacent leads will be described in detail. For convenience of explanation, one of the tie bar cut marks 14 between adjacent leads is indicated by reference numeral 14a, and the other is indicated by reference numeral 14b. As shown in FIG. 3, each end of the tie bar cut traces 14a and 14b has a tapered shape. In the present embodiment, in the tie bar cut mark portion 14a, the taper tip portion 14at is located on the lead tip side, the taper base portion 14ar is located on the sealing resin portion 12 side, and the taper surface (end surface) in FIG. The taper is inclined upward. On the other hand, in the tie bar cut mark portion 14b, the taper tip portion 14bt is located on the sealing resin portion 12 side, the taper root portion 14br is located on the lead tip side, and the taper surface (end surface) is obliquely downward in FIG. Tapered shape.

These tie bar cut traces 14a and 14b are viewed on a surface of the lead, in other words, ignoring the thickness of the lead, and the width of the tie bar cut trace 14 (tie bar 13) is W, the tie bar cut trace 14a, 14b, the distance between the straight lines L1 and L2 parallel to the lead 11 passing through the taper tip portions 14at and 14bt is d, the distance in the tie bar longitudinal direction from the taper tip portion 14at to the taper root portion 14ar is D, and the taper tip portion 14at is passed. When the distance on the straight line L2 from the intersection point P1 between the straight line L3 and the straight line L2 orthogonal to the taper surface to the intersection point P2 of the straight line L2 and the line segment S connecting the taper tip portion 14at to the taper base portion 14br is defined as w. , So as to satisfy the following formula (1).
W / D <w / d (1)

  A lead 11 having such a tie bar cut mark 14 is formed from a lead frame 15 shown in FIG. In the lead frame 15, a plurality of leads 11 are connected by tie bars 13. Since the tie bar 13 is provided so as to extend in a substantially right angle direction with respect to the lead 11, the yield does not deteriorate as in the case where the tie bar is provided obliquely. Then, the lead 11 having a shape as shown in FIG. 1 is obtained by punching and cutting (tie bar cutting) the tie bar 13 with a tie bar cutting jig so as to satisfy the relationship of the above formula (1). Details of this processing method will be described later.

  The tie bar cutting jig will be described with reference to FIGS. FIG. 5 is a diagram showing a schematic configuration of a tie bar cut punch. FIG. 6 is a cross-sectional view of a cutting blade provided in a tie bar cut punch. FIG. 7 is a diagram showing a schematic configuration of a tie bar cut die.

  As shown in FIG. 5, the tie bar cut punch 30 includes a plurality of cutting blades 31 and 32. The cutting blade 31 is provided at both ends of the punch 30, and punches and cuts both end portions of the tie bar 13. The cutting blade 32 is provided between the cutting blades 31 at a predetermined interval, and punches and cuts the tie bar 13 positioned between the adjacent leads 11. The cross-sectional shape of the cutting blade 32 is a parallelogram as shown in FIG. 6, and the tie bar 13 positioned between adjacent leads 11 is punched and cut so as to satisfy the relationship of the above formula (1). The tie bar cut traces 14a and 14b are formed.

On the other hand, the tie bar cut die 35 is a mold on which the lead frame 15 before processing is placed when performing tie bar cut. A sealing resin part arrangement part 36 for arranging the sealing resin part 12 is formed at substantially the center of the tie bar cut die 35. Grooves 37 and 38 into which the cutting blades 31 and 32 of the tie bar cut punch 30 enter are formed around the sealing resin portion arrangement portion 36. A bent portion 38 a having a shape corresponding to the shape of the cutting edge 32 is formed in the groove 38. When the cutting blade 32 of the punch 30 is inserted into and removed from the bent portion 38a, the tie bar 13 positioned between the adjacent leads 11 is punched and cut so as to satisfy the relationship of the above formula (1), and the tie bar cut trace portion 14a. , 14b are formed.
The tie bar cut punch 30 and the tie bar cut die 35 described above are examples of the “tie bar cut jig” in the present invention.

  When the lead frame 10 shown in FIG. 1 is manufactured using this tie bar cutting jig, first, the unprocessed lead frame 15 shown in FIG. 4 is arranged at a predetermined position of the tie bar cut die 35. And fix. Thereafter, the tie bar cut punch 30 is lowered. At this time, the cutting blade 32 of the punch 30 enters the bent portion 38 a of the groove 38 provided in the die 35. Note that the cutting edge 31 of the punch 30 enters the groove 37 of the die 35. Thereby, the tie bar 13 is punched and cut. Specifically, the tie bar 13 located between the adjacent leads 11 is punched and cut by the bent portion 38a of the die 35 and the cutting edge 32, and the tie bar cut trace portion 14 having a tapered shape satisfying the relationship of the above formula (1). Is formed. Further, both ends of the tie bar 13 are cut by the groove 37 and the cutting edge 31 of the die 35. Thus, the lead frame 10 shown in FIG. 1 is completed.

  In the lead frame 10 thus manufactured, the lead 11 is then bent by a molding device as shown in FIG. 8, and the tip portion of the lead frame 10 is soldered to the land 41 provided on the circuit board 40. Fixed. At this time, the solder 42 wets the lead 11 and may be thinly attached to the tie bar cut trace 14. As a result, whiskers are generated at the ends of the tie bar cut traces 14. FIG. 8 is a diagram showing a state where the tip of the lead is soldered to the circuit board.

  Here, the end portion of the tie bar cut mark portion 14 formed on the lead 11 has a shape as shown in FIG. 3 so as to satisfy the above formula (1). And the whisker which produces a short circuit between leads grows substantially perpendicularly. Therefore, even if a whisker is generated and grows at the end of one tie bar cut trace 14a (14b), it does not come into contact with the other tie bar cut trace 14b (14a). As a result, the tie bar cut traces 14a and 14b of the adjacent leads 11 are not connected by the whisker, so that it is possible to prevent a short circuit between the leads due to the whisker.

  As described above in detail, according to the lead frame 10 according to the first embodiment, the adjacent leads 11 include the tie bar cut trace portions 14a and 14b that satisfy the above formula (1). As a result, even if whisker is generated and grows at the end of one tie bar cut trace part 14a (14b), the other tie bar cut trace part 14b (14a) does not come into contact with each other. Can be prevented.

[Second Embodiment]
Next, a second embodiment will be described. The basic configuration of the second embodiment is substantially the same as that of the first embodiment, but differs in that a plating removal portion is provided on the lead. Therefore, in the following, the same components as those in the first embodiment will be denoted by the same reference numerals in the drawings, and the description thereof will be omitted as appropriate, and differences from the first embodiment will be described. A lead frame according to the second embodiment will be described with reference to FIG. FIG. 9 is a diagram showing a schematic configuration of a lead frame according to the second embodiment.

  As shown in FIG. 9, in the lead frame 50, a plating removal portion 51 is formed on the lead 11 by removing the plating on the lead surface. This plating removal portion 51 is provided between the tip of the lead 11 and the tie bar cut trace portion 14. The plating removal portion 51 is preferably formed at a height of about 0.5 mm when the lead 11 is bent. The plating removal part 51 may be formed at the time of tie bar cutting or lead bending. In the present embodiment, the plating removal portion 51 is formed with a size of about 50 μm (lead longitudinal direction).

  In the lead frame 50, when the lead 11 is soldered to the circuit board, the plating removal unit 51 does not wet the solder, so the plating removal unit 51 can stop the solder from getting wet. As a result, the solder does not reach the tie bar cut trace 14. Therefore, it is possible to suppress the occurrence of whiskers at the tie bar cut mark portion 14.

  Therefore, according to the lead frame 50 according to the second embodiment, it is possible to more reliably prevent the occurrence of a short circuit between the leads due to the whisker.

[Third Embodiment]
Finally, a third embodiment will be described. The basic configuration of the third embodiment is substantially the same as that of the first embodiment, but differs in that a recess is provided in the lead. Therefore, in the following, the same components as those in the first embodiment will be denoted by the same reference numerals in the drawings, and the description thereof will be omitted as appropriate, and differences from the first embodiment will be described. Thus, a lead frame according to the third embodiment will be described with reference to FIG. FIG. 10 is a diagram showing a schematic configuration of a lead frame according to the third embodiment.

  As shown in FIG. 10, in the lead frame 60, recesses 61 are formed on both side surfaces of the lead 11. This recess 61 is provided between the tip of the lead 11 and the tie bar cut trace 14. The recess 61 is preferably formed at a height of about 0.5 mm when the lead 11 is bent. Further, the recess 61 may be formed at the time of tie bar cutting or lead bending. In the present embodiment, the recess 61 is formed with a curvature of 0.15 mm and a depth of about 0.05 mm.

  In the lead frame 60, when the lead 11 is soldered to the circuit board, the concave portion 61 is formed, so that a thick solder layer is formed on the lead 11. That is, a thin solder layer is not formed on the lead 11. Therefore, the generation of whiskers can be suppressed.

  Therefore, according to the lead frame 60 according to the third embodiment, it is possible to more reliably prevent occurrence of a short circuit between leads due to whiskers.

  It should be noted that the above-described embodiment is merely an example and does not limit the present invention in any way, and various improvements and modifications can be made without departing from the scope of the invention. For example, in the above-described embodiment, the case where the present invention is applied to a lead frame in which leads are provided only in two directions from the sealing resin portion is illustrated, but the present invention has leads in four directions from the sealing resin portion. The present invention can also be applied to a provided lead frame.

  Further, in the above-described third embodiment, the recesses 61 are provided at both end portions of the lead 11 in the left-right direction in FIG. 10. It can also be provided at both ends. Furthermore, in the above-described second and third embodiments, the plating removal portion 51 and the recess 61 are provided, but both of them may be provided on the lead 11.

DESCRIPTION OF SYMBOLS 10 Lead frame 11 Lead 12 Sealing resin part 13 Tie bar 14 Tie bar cut trace part 14a, 14b Adjacent diver cut trace part 15 Lead frame 20 before processing Semiconductor chip 22 Metal wire 30 Tie bar cut punch 31, 32 Cutting edge 35 Tie bar cut die 37 , 38 Groove 38a Bent part

Claims (6)

In a lead frame comprising a sealing resin portion in which a semiconductor element is disposed, and a plurality of leads that are electrically connected to the semiconductor element and project laterally from the sealing resin portion,
The lead extends in a direction perpendicular to the longitudinal direction of the lead, and a tie bar that connects adjacent leads is punched and cut obliquely (tie bar cut) with respect to the longitudinal direction of the lead, and the end is tapered. With tie bar cut traces formed in
Each tie bar cut trace portion formed between the adjacent leads has a width of the tie bar on the lead surface, and between the straight lines L1 and L2 parallel to the lead passing through each taper tip of the tie bar cut trace portion. The distance is d, the distance in the tie bar longitudinal direction from one taper tip to the taper root is D, and from the intersection of the straight line L2 and the straight line L2 passing through one taper tip and perpendicular to the taper part, A lead frame characterized by satisfying a relationship of W / D <w / d, where w is a distance on the straight line L2 from the taper tip portion to the intersection of the straight line L2 and the line segment connecting the other taper base portion. . The lead frame according to claim 1,
The lead frame is characterized in that a plating removal portion is formed by removing plating on the lead surface between the tip of the lead and the trace portion of the tie bar. In the lead of the semiconductor device according to claim 1 or 2,
The lead frame is characterized in that a recess is formed between the tip and the tie bar cut trace. In a manufacturing method of a lead frame, comprising: a sealing resin portion in which a semiconductor element is disposed; and a plurality of leads that are electrically connected to the semiconductor element and project laterally from the sealing resin portion.
Each tie bar which extends in a direction perpendicular to the longitudinal direction of the leads and which connects adjacent leads is punched and cut obliquely (tie bar cut) with respect to the longitudinal direction of the leads, and remains between the adjacent leads. When forming the end portion of the cut trace portion in a taper shape, the width of the tie bar on the lead surface is W, and the lead passes through each taper tip portion of each tie bar cut trace portion remaining after the tie bar cut between adjacent leads. The distance between the straight lines L1 and L2 parallel to D, the distance in the tie bar longitudinal direction from one taper tip to the taper base, D, and the straight line L3 passing through one taper tip and perpendicular to the taper part The distance on the straight line L2 from the intersection point with the straight line L2 to the intersection point between the straight line L2 and the line segment connecting one taper tip portion to the other taper base portion is expressed as w. To method of manufacturing a lead frame and satisfies the relationship of W / D <w / d. In the manufacturing method of the lead frame according to claim 4,
A lead frame manufacturing method, wherein at least one of a plating removal part or a concave part from which a lead surface is removed is formed between a tip of the lead and the trace part of the tie bar cut. In a lead frame manufacturing apparatus comprising: a sealing resin portion in which a semiconductor element is disposed; and a plurality of leads that are electrically connected to the semiconductor element and project laterally from the sealing resin portion.
Each tie bar which extends in a direction perpendicular to the longitudinal direction of the leads and which connects adjacent leads is punched and cut obliquely (tie bar cut) with respect to the longitudinal direction of the leads, and remains between the adjacent leads. It has a tie bar cutting jig that forms the end of the cut trace part into a taper shape,
On the lead surface, the tie bar cut jig has a width between the straight lines L1 and L2 parallel to the lead passing through the taper tip of each tie bar cut mark portion remaining between adjacent leads on the width of the tie bar. D, the distance in the tie bar longitudinal direction from one taper tip to the taper base, D, and the taper of one taper from the intersection of the straight line L2 and the straight line L3 passing through the one taper tip and perpendicular to the taper part. A cross-sectional shape for performing tie bar cutting so as to satisfy the relationship of W / D <w / d, where w is the distance on the straight line L2 from the tip to the intersection of the straight line L2 and the line segment connecting the other taper base. A lead frame manufacturing apparatus comprising a parallelogram-shaped cutting blade.

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