JP3863218B2 - Molding device for hoop-shaped lead frame - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a hoop-like lead frame used in the manufacture of electronic components such as diodes, and is made of a synthetic resin that packages circuit element portions such as semiconductor chips provided at appropriate pitch intervals along the longitudinal direction of the lead frame. The present invention relates to an apparatus for forming the mold part.
[0002]
[Prior art]
  In general, when forming a mold portion on a hoop-shaped lead frame, as shown in FIG. 1, a circuit element such as a semiconductor chip is provided between a pair of left and right lead terminals A1 formed at appropriate intervals of a pitch P1. In the hoop-shaped lead frame A, a portion having an appropriate length L1 (L1 = P1 × (N−1)) including the N lead terminals A1 of the lead frame A is divided into a lower mold B and an upper mold C. And injecting synthetic resin in a molten state into a cavity E formed in a recess in the mating surfaces of both molds B and C, to each of the lead terminals A1 in the portion of the appropriate length L1. On the other hand, after molding the mold part D and then releasing the sandwiching of the lead frame A by the two molds B and C, the lead frame A is moved to the longitudinal direction by one pitch P at the appropriate length L1. And to repeat that only the transfer length plus the (L1 + P1).
[0003]
  In this molding, it is necessary that the pitch interval P1 of each lead terminal A1 in the lead frame A exactly matches the pitch interval P2 of each cavity E in both molds B and C. For this purpose, The portion of the lead frame A that is sandwiched between the two molds B and C must be held in an appropriate tension state.
[0004]
  Therefore, in the conventional molding apparatus, as shown in FIG. 2, a plurality of teeth are provided on the outer peripheral surface both on the inlet side to both molds B and C and on the outlet side from both molds B and C. Feed wheels F and G each having a feed hole F and G are provided, and teeth on the outer peripheral surfaces of the feed wheels F and G are formed in the hoop-like lead frame A at regular pitch intervals (see FIG. (Not shown), the lead frame A is kept in an appropriate tension state at all times between the feed wheels F and G of the lead frame A by intermittent rotation of the feed wheels F and G. In this state, the length L1 is transferred intermittently by a length (L1 + P1) obtained by adding one pitch P1 to the length L1.
[0005]
  In FIG. 2, each of the feed wheels F and G is provided with presser wheels F1 and G1 of the lead frame A.
[0006]
  In the conventional molding apparatus, both molds B and C are moved up and down by a hydraulic cylinder, and both molds B and C are moved toward the lead frame A at the same time. And a lower die B, which is the other die, without moving up and down one of the two die C, B, for example, the upper die C, as a hydraulic cylinder. As the lower mold B moves up and down, the portion between the two feed wheels F and G in the lead frame A is pushed up toward the upper mold C by both molds B and C. Some are configured to be sandwiched.
[0007]
[Problems to be solved by the invention]
  However, in the former, an extra tension is applied to the lead frame A by sandwiching the portion between the two feed wheels F and G of the lead frame A with both molds B and C without moving up and down. Since there is no chipping, there is an advantage that no deviation occurs between the pitch interval P1 of each lead terminal A1 in the lead frame A and the pitch interval P2 of the cavity E in the molds B and C. On the other hand, both dies B and C must be configured to move up and down with a hydraulic cylinder.IfTherefore, there is a problem that not only the molding apparatus is complicated and large in size, but the price is greatly increased, and it is difficult to adjust the parallelism of both molds B and C.
[0008]
  On the other hand, in the latter, since only the other mold, for example, the lower mold B is moved up and down, the structure is simple, the size can be reduced, the cost is low, and the parallelism of both molds B and C is high. However, as shown by the two-dot chain line in FIG. 2, the lead frame A is moved by the upward movement of the lower mold B so that the lower mold B and the upper mold C can be adjusted. Between the two molds B and C and the double feed wheels F and G of the lead frame A, with both ends fixed by the double feed wheels. Since the lead frame A is extended with an excessive tension, the pitch interval P1 of each lead terminal A1 in the lead frame A and the pitch of the cavity E in the molds B and C are extended. Deviation occurs between the interval P2 and molding A mold section D, there is a problem that the can mold misalignment between the lead frame terminals of the lead frame.
[0009]
  According to the present invention, in the latter molding apparatus, it is possible to reliably reduce the extension that occurs when the portion between the two feed wheels of the lead frame is pressed against the other mold by the vertical movement of one mold. This is a technical issue.
[0010]
[Means for Solving the Problems]
  In order to achieve this technical problem, “claim 1” of the present invention provides:
"One of the pair of molds disposed on both sides of the hoop-shaped lead frame transferred in the longitudinal direction is configured to reciprocate toward the other mold, while the two molds of the lead frame A feed wheel in which the lead frame is intermittently transported in the longitudinal direction by an appropriate length on each of the inlet side and the outlet side of the mold, and teeth on the outer peripheral surface of the both feed wheels are the leads. In a molding apparatus in which the lead frame is linearly extended and arranged to mesh with a feed hole in the frame,
  Either or both of the feed wheels are mounted on a bracket having a center of rotation at a location that is appropriately spaced from the center of rotation of the feed wheel toward the other mold in a direction crossing the lead frame. The bracket is configured to rotate in the direction of the other mold as the one mold moves toward the other mold, and the center of rotation of the bracket is set. , When the bracket is rotated in the direction of the other mold, the feed wheel mounted on the bracket is set to a position where the feed wheel moves so as to approach both molds in the longitudinal direction of the lead frame. In addition, a guide member for the surface on the one mold side of the lead frame is provided so as to extend along the longitudinal direction of the lead frame.It is characterized by that. "
Is.
[0011]
  “Claim 2”
"One of the pair of molds disposed on both sides of the hoop-shaped lead frame transferred in the longitudinal direction is configured to reciprocate toward the other mold, while the two molds of the lead frame A feed wheel in which the lead frame is intermittently transported in the longitudinal direction by an appropriate length on each of the inlet side and the outlet side of the mold, and teeth on the outer peripheral surface of the both feed wheels are the leads. In a molding apparatus in which the lead frame is linearly extended and arranged to mesh with a feed hole in the frame,
  Either or both of the feed wheels are mounted on a bracket having a rotation center at a location that is appropriately spaced from the rotation center of the feed wheel toward the other mold in a direction crossing the lead frame. Then, when the bracket is rotated in the direction of the other mold, the feed wheel mounted on the bracket moves so as to approach both molds in the longitudinal direction of the lead frame. The bracket is provided with a guide member for the surface of the one die side of the lead frame so as to extend along the longitudinal direction of the lead frame, and further on the one mold side. The contact body adapted to come into contact with the guide member when the one mold approaches the other mold is elastically attached to the one mold side by a spring means. Characterized in that provided equity. "
Is.
[0012]
[Operation and effect of the invention]
  As described above, either one or both of the feed wheels arranged on the inlet side and the outlet side to both molds are moved so that one mold approaches the other mold. Accordingly, by configuring the lead frame so as to approach both molds in the longitudinal direction, the portion of the lead frame between the two feed wheels is forcibly moved by the approach movement of one mold to the other mold. It is possible to prevent an excessive tension from acting on this when bent in an inclined manner by moving the lead frame toward the two dies in the one or both feed wheels in the longitudinal direction.
[0013]
  Therefore, according to the present invention, one of the two dies is reciprocated while the hoop-like lead frame is held in a straight tension state by the two feed wheels and is intermittently transferred. In this case, the length of the lead frame in the lead frame and the pitch of the cavity in the die can be reduced. It is possible to reliably prevent the occurrence of a deviation between the gaps and, in turn, the occurrence of a deviation between each lead terminal in the lead frame and the mold part formed by the mold, or , It has the effect of reducing the misalignment.
[0014]
  Also, either one or both of the feed wheels are moved closer to the two molds in the longitudinal direction of the lead frame as one mold moves closer to the other mold. That is, "Claim 1The feed wheel is mounted on a bracket having a center of rotation at a site that is appropriately spaced from the center of rotation toward the other mold in a direction transverse to the lead frame. The bracket is configured to rotate in the direction of the other mold as the one mold moves toward the other mold, and the center of rotation of the bracket is By setting the feed wheel attached to the other mold to move in the longitudinal direction of the lead frame so as to approach both molds when rotating in the direction of the other mold, it is easy with a simple structure. In particular, this “Claim 1Is that the part of the lead frame between the feed wheel and the mold can be guided by the guide member provided on the bracket, so that the lead frame can be prevented from swinging or reduced in this part. There exists an advantage which can promote the above-mentioned effect more.
[0015]
  Furthermore, Configuring the bracket to rotate in the direction of the other mold as one mold approaches the other mold,Claim 2As described in the above, a simple structure is provided on one mold side by providing a contact body that comes into contact with the guide member when the one mold approaches the other mold. It can be easily realized with this.Claim 2"It is impossible to rotate the bracket during the approaching movement of one mold to the other mold by elastically supporting the contact body on one mold side with spring means. When a force is generated, the pivoting of the bracket by the contact body is stopped by the spring means, so that it is possible to more reliably avoid applying an excessive tension to the lead frame, further promoting the above effect. There are advantages you can do.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
  Embodiments of the present invention will be described below with reference to FIGS.
[0017]
  In this figure, reference numeral A denotes a hoop-shaped lead frame, reference numerals B and C denote molds for forming a mold portion D at each lead terminal A1 in the lead frame A, Of the molds B and C, the upper mold C on the upper surface side of the lead frame A is configured not to move up and down, but the lower mold B on the lower side of the lead frame A is connected to the upper mold by a hydraulic cylinder or the like (not shown). It is configured to move up and down toward the mold C.
[0018]
  Reference numeral 1 denotes a feed wheel disposed on the inlet side to the molds B and C, and reference numeral 2 denotes a feed wheel disposed on the outlet side from the molds B and C. The feed wheels 1 and 2 are engaged with feed holes (not shown) formed in the hoop-like lead frame A at regular pitch intervals as in the conventional case. With the lead frame A extended in a straight line, the portion between the two feed wheels 1 and 2 in the lead frame A is always in an appropriate tension state by intermittent rotation of the two feed wheels 1 and 2. While being held, it is configured to intermittently transfer by a length (L1 + P1) obtained by adding one pitch P1 to the appropriate length L1. Reference numerals 3 and 4 denote the holding wheels of the lead frame A with respect to the both feed wheels 1 and 2.
[0019]
  Reference numeral 5 denotes an inlet-side bracket to which the inlet-side feed wheel 1 and its presser wheel 3 are attached. The inlet-side bracket 5 is located above the feed wheel 1, that is, above the center of rotation of the feed wheel 1. At a portion spaced from the lead frame A in the direction crossing the lead frame A toward the mold C, the pivot is fixedly supported by a pivot pin 6 with respect to the airframe side. A guide member 7 extending toward the molds B and C along the lower surface of the lead frame A is provided.
[0020]
  Reference numeral 8 denotes an outlet side bracket to which the outlet side feed wheel 2 and its pressing wheel 4 are attached. The outlet side bracket 8 is a part above the feed wheel 2, that is, the rotation center of the feed wheel 2. At a portion spaced from the lead frame A in a direction crossing the lead frame A toward the upper mold C, the pivot bracket 9 is pivotally attached to the airframe side so as to be rotatable. A guide member 10 extending toward the molds B and C along the lower surface of the lead frame A is provided.
[0021]
  In this case, the pivot pin 6 which is the pivot center of the inlet side bracket 5 and the pivot pin 9 which is the pivot center of the outlet bracket 8 are connected to the upper mold C. When the feed wheels 1 and 2 mounted on the lead frame A are rotated in the direction of, the feed wheels 1 and 2 are provided so as to move in the longitudinal direction of the lead frame A so as to approach both dies B and C.
[0022]
  On the other hand, on the lower mold C side that moves up and down toward the upper mold C, bell crank levers 11 and 12 are pivotally attached to the left and right sides by pins 13 and 14, respectively. Between the other end of 11 and 12, and the lower metal mold | die C side, the tension springs 17 and 18 which urge | bias so that the said other end contacts the stoppers 15 and 16 of the lower metal mold C side are provided.
[0023]
  On the other hand, at the tips of the bell crank levers 11 and 12, rotatable roller-type contact bodies 19 and 20 are provided, and when the lower mold B is moved up, both contact bodies 19 and 20 Each bracket 20 contacts the lower surfaces of the guide members 7 and 10 in both brackets 5 and 8 and pushes them up, so that both brackets 5 and 8 pivot their pivot pins 6 and 9 at their base ends. It is configured to rotate upward about the center.
[0024]
  In this configuration, when the intermittent transfer of the lead frame A is stopped, the lower mold B is moved up so that the portion of the lead frame A between the two feed wheels 1 and 2 becomes the lower mold. It is pushed upward by the upward movement of B and is forced to bend in an inclined shape, and then comes into contact with the lower surface of the upper mold C and is sandwiched between both molds B and C.
[0025]
  During the upward movement of the lower mold B, the two contact bodies 19 and 20 provided on both the left and right sides of the lower mold B come into contact with the lower surfaces of the guide members 7 and 10 in the brackets 5 and 8, respectively, and push it up. As a result, the brackets 5 and 8 pivot upward with the pivot pins 6 and 9 at the base ends thereof as pivot centers. Then, due to the upward rotation of both the brackets 5 and 8, the double feed wheels 1 and 2 attached to the brackets 5 and 8 arePlace ofOf the lead frame A by an appropriate distance S from the mounting position.In the longitudinal directionSince it moves so that it may approach both metal mold | die B and C, the part between the both feed wheels 1 and 2 of the said lead frame A is forced by the approach movement to the upper metal mold | die C of the lower metal mold B When the lead frame A is bent to the two molds B and C of the double-feed wheels 1 and 2, the excessive tension acts on this.LongitudinallyThe approach movement can be surely prevented, and the elongation generated in the lead frame A can be eliminated or reduced.
[0026]
  The brackets 5 and 8 are provided with guide members 7 and 10 for the lead frame A, so that a portion of the lead frame A between the feed wheels 1 and 2 and the dies B and C is provided. Can be guided by the guide members 7, 10, so that the swing motion of the lead frame A in this portion can be eliminated or reduced.
[0027]
  Further, the two contact members 19, 20 in the lower mold B are supported by the springs 17, 18 with respect to the lower mold B that moves up and down, so that the lower mold B approaches the upper mold C. If an unreasonable force is generated during the movement of the brackets 5 and 8 in the upward direction, the upward rotation of the brackets 5 and 8 by the both contact bodies 19 and 20 is stopped by the springs 17 and 18. Therefore, it is possible to more reliably avoid applying excessive tension to the lead frame A.
[0028]
  In the above-described embodiment, both the feed wheel 1 on the inlet side and the feed wheel 2 on the outlet side of both molds B and C are arranged along the longitudinal direction of the lead frame A toward both molds B and C. However, the present invention is not limited to this, and only one of the feed wheel 1 on the inlet side and the feed wheel 2 on the outlet side is directed toward both molds B and C. Lead frame ALongitudinallyThe present invention may be configured to move close to each other. In the present invention, instead of fixing the upper mold C and moving the lower mold B up and down as in the above-described embodiment, the lower mold Needless to say, the present invention can also be applied to the case where the mold B is fixed and the upper mold C is moved up and down.
[0029]
  The position where the pivot pins 6 and 9 at the base ends of the brackets 5 and 8 are provided in a portion along the longitudinal direction of the lead frame A is most preferably a portion directly above the both feed wheels 1 and 2. Or on the outer side of the both feed wheels 1 and 2 (the side away from both dies B and C). Since the wheels 1 and 2 can be moved closer to the molds B and C without lowering from the position, the swing motion of the lead frame A can be reduced.
[0030]
  On the other hand, when the pivot pins 6 and 9 are positioned inside the feed wheels 1 and 2 (sides close to the molds B and C), when the brackets 5 and 8 are turned upward, Since the both feed wheels 1 and 2 are once lowered from the present position and then moved closer to both molds B and C, the swing motion of the lead frame A increases.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a state in which a mold part is molded with respect to a lead frame.
FIG. 2 is a view showing a conventional molding apparatus.
FIG. 3 is a diagram showing an embodiment according to the present invention.
4 is an enlarged view of a main part of FIG. 3;
FIG. 5 is a diagram illustrating an operation state of FIG. 4;
[Explanation of symbols]
  A Lead frame
  B, C mold
  D Mold part
  1, 2 Feed wheel
  3,4 presser wheel
  5,8 Bracket
  6,9 pivot pin
  7,10 Guide member
  19, 20
  17, 18 Spring

Claims (2)

One of the pair of molds disposed on both sides of the hoop-shaped lead frame transferred in the longitudinal direction is configured to reciprocate toward the other mold, while the two molds of the lead frame A feed wheel in which the lead frame is intermittently transported in the longitudinal direction by an appropriate length on each of the inlet side and the outlet side of the mold, and teeth on the outer peripheral surface of the both feed wheels are the leads. In a molding apparatus in which the lead frame is linearly extended in a feed hole in the frame and arranged to mesh with the feed hole,
Either or both of the feed wheels are mounted on a bracket having a center of rotation at a location that is appropriately spaced from the center of rotation of the feed wheel toward the other mold in a direction crossing the lead frame. The bracket is configured to rotate in the direction of the other mold as the one mold moves toward the other mold, and the center of rotation of the bracket is set. When the bracket is rotated in the direction of the other mold, the feed wheel mounted on the bracket is set to a position where the feed wheel moves so as to approach both molds in the longitudinal direction of the lead frame. And a guide member for the surface on the one mold side of the lead frame is provided so as to extend along the longitudinal direction of the lead frame. Molding apparatus of the molded part for the frame. One of the pair of molds disposed on both sides of the hoop-shaped lead frame transferred in the longitudinal direction is configured to reciprocate toward the other mold, while the two molds of the lead frame A feed wheel in which the lead frame is intermittently transported in the longitudinal direction by an appropriate length on each of the inlet side and the outlet side of the mold, and teeth on the outer peripheral surface of the both feed wheels are the leads. In a molding apparatus in which the lead frame is linearly extended in a feed hole in the frame and arranged to mesh with the feed hole,
Either or both of the feed wheels are mounted on a bracket having a center of rotation at a location that is appropriately spaced from the center of rotation of the feed wheel toward the other mold in a direction crossing the lead frame. Then, when the bracket is rotated in the direction of the other mold, the feed wheel mounted on the bracket moves so as to approach both molds in the longitudinal direction of the lead frame. The bracket is provided with a guide member for the surface of the one die side of the lead frame so as to extend along the longitudinal direction of the lead frame, and further on the one die side. The contact body adapted to come into contact with the guide member when the one mold approaches the other mold is elastically attached to the one mold side by a spring means. Molding apparatus of the mold portion to the hoop-like lead frame, characterized in that provided in lifting.

Images