JP2013081965A - Powder molding method for electronic components and powder molding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding method and a molding device for chips in which a stress applied on a wire is suppressed.SOLUTION: The powder molding method for electronic components includes: a step in which a core rod having a diameter larger than that of a wire is protruded from a lower punch inserted into a lower part of a die hole and extended up to a top part of the die hole; a step in which power is supplied to the die hole; a step in which an upper punch is lowered to the top part of the die hole; a temporary molding step in which the upper punch is lowered to the die hole and the lower punch is raised so that the powder in the die hole is pressurized; a step in which the wire is inserted into a through hole formed by lowering the core rod; a practical molding step in which the upper punch is lowered to additionally pressurize the powder; a step in which the upper punch is raised back to an upper position of the lower hole and the wire and lower punch are both raised so that the molded chip is pushed out to the top part of the die hole; a step in which the wire is cut; and a step in which the molded chip is discharged into a collection box, the wire is returned to a position of the upper punch, and then the lower punch is returned to the lower part of the die hole.

Description

  The present invention relates to an electronic component powder molding method and a powder molding apparatus, and more particularly, to an electronic component powder molding method and a powder molding apparatus having a structure in which a wire is inserted into a molded powder.

  Patent Document 1 discloses a conventional molding method in which a tantalum powder is hardened to make a capacitor chip. The chip is molded by putting tantalum powder into the mold, piercing the wire into the tantalum powder, and pressing the tantalum powder with the upper and lower punches. The chip is separately sintered at a high temperature, and a terminal serving as a cathode is attached to the side surface of the chip. According to such a molding method, not only a tantalum capacitor using a tantalum metal powder but also an electronic component using a ceramic powder such as barium titanate, such as a temperature sensor, can be produced. Further, in terms of the number of wires, not only an electronic component with one wire but also an electronic component with two wires can be produced.

  When the wire is stabbed into metal powder or ceramic powder and pressed, there is a problem that stress is accumulated in the wire due to the pressing load, and the element or the wire is deformed by sintering. Further, as the powder is refined and the chip size is reduced, the wire having a smaller diameter is used, but there is a problem that the powder cannot be easily pierced.

Japanese Patent Laid-Open No. 7-50231

  An object of the present invention is to provide a powder molding method and a powder molding apparatus for an electronic component in which a wire can be easily inserted and stress applied to the wire can be suppressed.

  In order to achieve the above object, an electronic component powder molding method according to the present invention is a powder molding method for an electronic component in which a chip is formed by inserting and pressing a wire into powder put into a mold, A core rod having a diameter larger than that of the wire is protruded from the lower punch inserted in the lower part of the hole and extended to the top of the mold hole (S1), a step of supplying powder to the mold hole (S2), and an upper punch A step (S3) of lowering to the top of the mold hole, and a temporary molding step (S4) in which the upper punch is lowered into the mold hole by a predetermined depth and the lower punch is raised to press the powder in the mold hole. And a step (S5) of inserting a wire into a through hole formed by lowering the core rod, a main molding step (S6) of lowering the upper punch and further pressing the powder, and raising the upper punch, Return to the position above the hole and wire and lower punch A step of extruding the chip formed by raising both of them to the top of the mold hole (S7), a step of clamping the molded chip and cutting the wire (S8), and discharging the molded chip to the collection box, And a step (S9) of raising and returning to the position of the upper punch and lowering the lower punch to return to the lower portion of the mold hole.

  The powder molding apparatus for electronic parts according to the present invention is a powder molding apparatus for electronic parts that makes a chip by inserting and pressing a wire into powder put into a mold, and has a mold hole into which powder is put. A mold, a powder supply box that slides the upper surface of the mold to supply powder to the mold hole, an upper punch that presses and molds the powder in the mold hole from above, and a powder in the mold hole from below A lower punch that is pressed and molded, a wire that moves up and down to protrude downward from the upper punch, and a core rod that has a larger diameter than a wire that moves up and down to protrude upward from the lower punch And a cutter for cutting the wire extending to the upper part of the molded chip, and a clamp for grasping the chip and discharging it to the collection box, and the core rod is removed from the lower punch inserted in the lower part of the mold hole. Protruding and the core rod In a state of being extended to the top of the die hole, powder is put into the die hole, the upper punch is lowered from the top of the die hole by a predetermined depth, and the lower punch is raised to raise the die. The powder in the mold hole is pressed and temporarily molded, then the wire is inserted into a through-hole formed by lowering the core rod, and the powder in the mold hole is further pressed with the upper punch to perform main molding. It is characterized by performing.

  The upper punch is characterized in that the inner diameter of the hole through which the wire passes is larger than the outer diameter of the core rod, and the core rod enters the wire hole during temporary molding.

  According to the powder molding method for electronic parts of the present invention, since the steps S1 to S6 are provided, the wire is inserted into the through-hole having a diameter larger than that of the wire formed in the powder, so that the wire is not bent. Can be inserted very easily. In addition, the powder molding process is provided in two stages of temporary molding (S4) and final molding (S6), and the wire is pressed because the temporary molding is completed and the wire is inserted into the through hole. Since it is only time, it is possible to prevent the wires from accumulating so much stress.

  According to the powder molding apparatus for an electronic component of the present invention, a core rod having a diameter larger than that of the wire moving up and down is provided so as to protrude upward from the lower punch, and the through hole into which the wire is inserted is temporarily molded by the core rod. Therefore, the wire can be inserted very easily. Also, the control is performed in two stages of temporary molding and final molding, and the wire is pressed only during the final molding after the temporary molding is finished and the wire is inserted into the through hole. Compared to the case of controlling, it is possible to prevent the wire from accumulating so much stress.

  Since the inner diameter of the hole of the wire of the upper punch is made larger than the outer diameter of the core rod, the core rod can enter the wire hole during temporary molding. Thereby, when lowering the upper punch at the time of temporary molding, it is not necessary to lower the wire and the core bar in synchronization. Since the vertical movement of the wire and the core rod is separated from the operation of the upper punch, the control can be simplified.

It is a front view of the powder molding apparatus of the electronic component by this invention. It is a left view of FIG. It is a principal part front view containing the metal mold | die of FIG. It is process drawing which shows the powder molding method of the electronic component by this invention. 3 is a flowchart showing a method for powder molding an electronic component according to the present invention. It is a perspective view of the chip | tip shape | molded with the powder shaping | molding apparatus by this invention.

  Hereinafter, a powder molding method and a powder molding apparatus for an electronic component according to the present invention will be described with reference to the drawings.

  FIG. 1 is a front view of an electronic component powder molding apparatus according to the present invention. FIG. 2 is a left side view of the powder molding apparatus of FIG. The powder molding apparatus 100 is a molding apparatus that makes a chip of a ceramic electronic component having two wires. As shown in FIGS. 1 and 2, a powder molding apparatus 100 includes a mold 1 for pressing and compacting powder to mold a chip, an upper punch driving AC servo motor 2 for driving an upper punch, and a lower punch driving AC for driving a lower punch. Servo motor 3, powder container 4, powder supply box 5, cutter 6, two wire spools 7, wire feed mechanism 8 for feeding the wire 12 with an air cylinder, collection box 11 for storing the molded chips, and control box 9, An operation panel 10 is included. The powder molding apparatus 100 is not limited to this, but has a width of 850 mm, a depth of 550 mm, and a height of 1800 mm. The pressing force of the powder is about 200 kgf at maximum.

  A chip made by pressing and compacting the ceramic powder 17 by the powder molding apparatus 100 is separately sintered at a high temperature and packaged to become a ceramic electronic component. The powder 17 is stored in the powder container 4 and sent out to the powder supply box 5 little by little. As shown in the drawing circle on the right side of FIG. 1, when the powder supply box 5 slides on the upper surface of the mold 1, the powder 17 falls from the bottom of the powder supply box 5 into the mold hole 1a, and the mold hole 1a. Is filled with powder 17.

  FIG. 3 is a front view of a main part including the mold of FIG. A lower punch 14 that can be inserted into the mold hole 1 a is provided on the lower side of the mold 1. The lower punch 14 is controlled so that the core rod 15 passes through a hole provided along the axial direction and protrudes from the tip of the lower punch 14. An upper punch 13 that can be inserted into the mold hole 1 a is provided on the upper side of the mold 1. The upper punch 13 is controlled so that the wire 12 passes through a hole provided along the axial direction and protrudes from the tip of the upper punch 13. In FIG. 3, only one set of wires is shown for the upper punch 13 and the lower punch 14, but two sets may be provided corresponding to two wires. The depth of the mold hole 1a is about 15 mm.

  FIG. 4 is a process diagram illustrating a powder molding method for an electronic component according to the present invention. FIG. 5 is a flowchart illustrating a method for powder molding an electronic component according to the present invention. 4A to 4I correspond to S1 to S9 in FIG. 4 and 5 will be described together. FIG. 4A shows a step of projecting the core rod 15 from the lower punch 14 inserted in the lower part of the mold hole 1a and extending it to the top of the mold hole 1a (S1 in FIG. 5). The lower punch 14 is positioned at the lower reference point 19, and the reference point 19 varies depending on the height of the chip to be molded. The upper punch 13 is at a predetermined position above the mold 1. The upper punch 13 has a hole through which the wire 12 passes, and the wire 12 is controlled to protrude downward from the tip of the upper punch 13.

  FIG. 4B shows a step of supplying the powder 17 to the mold hole 1a (S2 in FIG. 5). The powder 17 is supplied by sliding the powder supply box 5 as shown in FIG. The powder 17 is filled so as to surround the core rod 15. The diameter of the core rod 15 is larger than that of the wire 12. FIG. 4C is a step of lowering the upper punch 13 from the upper position to the top of the mold hole 1a (S3 in FIG. 5). In this state, the lower end of the wire 12 and the upper end of the core rod 12 are in contact. FIG. 4D shows a temporary molding step (S4 in FIG. 5) in which the upper punch 13 is lowered to the mold hole 1a by a predetermined depth and the lower punch is raised to press the powder 17 in the mold hole 1a. ). Since the inner diameter of the hole through which the wire 12 of the upper punch 13 passes is larger than the outer diameter of the core rod 15, a part of the upper end of the core rod 15 is part of the upper punch 13 as shown in FIG. Enter a little into the hole. FIG. 4E shows a step of lowering the core rod 15 to form a through hole 18 in the center of the powder and lowering the wire 12 into the through hole 18 and inserting it (S5 in FIG. 5). . Here, for example, since the diameter of the core rod 15 is 0.27 mm and the diameter of the wire 12 is 0.25 mm, the wire 12 can be easily inserted into the through hole 18. When the core rod 15 is lowered, if it is lowered synchronously with the lower end of the wire 12 in contact with the upper end of the core rod 15, if the molded body is soft even after temporary molding, There is an advantage that the peripheral wall does not collapse and the insertion of the wire 12 into the through hole 18 becomes easy.

  FIG. 4F shows a main molding process (S6 in FIG. 5) in which the upper punch 13 is lowered and the powder 17 is further pressed to form a chip. The through hole 18 is broken by the pressing, and the powder 17 is molded so as to grasp the wire 12. Although the lower punch 14 is not moved during the main molding, the lower punch 14 may be slightly raised upward as in the temporary molding. Thereby, the equal pressing from the upper and lower sides of the powder is possible. In FIG. 4G, the upper punch 13 is raised and returned to the upper position from the mold hole 1a, and the wire 12 and the lower punch 14 are lifted together to push the molded chip onto the top of the mold hole 1a. This is the process (S7 in FIG. 5). FIG. 4H is a step (S8 in FIG. 5) in which the molded chip is grasped by the clamp 20 and the wire 12 is cut by the cutter 6. FIG. 4 (I) shows that the molded chip 16 is discharged into the collection box 11, the wire 12 is raised and returned to the original position of the upper punch 13, and the lower punch 14 is lowered to the lower part of the mold hole 1a. This is the returning step (S9 in FIG. 5).

  FIG. 6 is a perspective view of a chip molded by the powder molding apparatus according to the present invention. The chip in FIG. 6A is a perspective view of a chip that becomes a cylindrical capacitor. A wire serving as an anode is inserted into the powder. In addition, the metal provided so that the circumference | surroundings of a powder body may be covered becomes a cathode separately. The chip in FIG. 6B is a perspective view of a chip that becomes a prismatic capacitor. The chip in FIG. 6C is a two-legged ceramic electronic component. The two legs are non-polar leads without + and-poles. Thus, the molding apparatus 100 according to the present invention can be applied to molding of ceramic electronic components and capacitors. Of course, the shape of the mold is variously changed based on the specifications.

  According to the present invention, a thinner wire can be inserted into the powder body, which is suitable for molding ceramic electronic components and capacitors.

DESCRIPTION OF SYMBOLS 1 Mold 1a Mold hole 2 Upper punch drive AC servo motor 3 Lower punch drive AC servo motor 4 Powder container 5 Powder supply box 6 Cutter 7 Wire spool 8 Wire feed mechanism 9 Control box 10 Operation panel 11 Collection box 12 Wire 13 Top Punch 14 Lower punch 15 Core rod 16 Tip 16a Body 17 Powder 18 Through hole 19 Lower reference point 20 Clamp 100 Powder molding apparatus S1 to S9

Claims (3)

It is a powder molding method of an electronic component that makes a chip by inserting and pressing a wire into powder put into a mold,
A step (S1) of projecting a core rod larger in diameter than the wire from the lower punch inserted in the lower part of the mold hole and extending it to the top of the mold hole;
Supplying powder to the mold hole (S2);
A step of lowering the upper punch to the top of the mold hole (S3);
Temporary molding step (S4) of lowering the upper punch into the mold hole by a predetermined depth, raising the lower punch, and pressing the powder in the mold hole;
Inserting a wire into a through hole formed by lowering the core rod (S5);
A main molding step (S6) of lowering the upper punch and further pressing the powder;
A step of raising the upper punch and returning it to the position above the mold hole, and raising the wire and the lower punch together to push the molded chip to the top of the mold hole (S7);
Clamping the molded chip and cutting the wire (S8);
A step (S9) of discharging the molded chip to a collection box, raising the wire to return it to the position of the upper punch, and lowering the lower punch to return to the lower part of the mold hole (S9). Powder molding method for parts.
A powder molding apparatus for electronic parts that makes a chip by inserting and pressing a wire into powder put into a mold,
A mold having a mold hole into which powder is charged;
A powder supply box that slides the upper surface of the mold and supplies powder to the mold hole;
An upper punch for pressing the mold hole powder from above and molding;
A lower punch for pressing and molding the powder in the mold hole from below;
A wire that moves up and down to protrude downward from the upper punch and is inserted into the mold hole;
A core rod larger in diameter than the wire that moves up and down so as to protrude upward from the lower punch,
A cutter that cuts the wire that extends to the top of the molded chip;
A clamp for grasping the chip and discharging it to the collection box,
The core rod is protruded from the lower punch inserted in the lower portion of the mold hole, and the core rod is extended to the top of the mold hole, and powder is poured into the mold hole, and the mold The upper punch is lowered from the top of the hole by a predetermined depth and the lower punch is raised, the powder in the mold hole is pressed and temporarily molded, and then the core rod is lowered to the through hole formed in the through hole. A powder molding apparatus for electronic parts, wherein a wire is inserted and the powder in the mold hole is further pressed by the upper punch to perform the main molding.
  3. The powder molding apparatus for an electronic component according to claim 2, wherein the upper punch has an inner diameter of a hole through which the wire passes larger than an outer diameter of the core rod, and the core rod enters the wire hole during temporary molding.

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