JP2010240697A - Powder press forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a powder press forming apparatus that can uniform a filling density and form an inexpensive ceramic substrate formed body. <P>SOLUTION: In the powder press forming apparatus 10 which includes: a mold composed of a die 14, a lower punch 15 and an upper punch 16; and a feeder 18 for filling ceramic granulating powder 12 in a space 17 formed by the upper face of the lower punch 15 and the wall face of a through hole 13, and forms a ceramic substrate formed body 11 by filling the ceramic granulating powder 12 in the space 17 and by press-forming with the lower punch 15 and the upper punch 16, the feeder 18 is composed of a box body with the bottom made an opening 19, and is provided with a levelling plate 23 which makes the ceramic granulating powder 12 supplied from the opening 19 into the space 17 flush with the upper face of the die 14, which is pressurized through a pressurizing body 22 from the inside of the tip end wall bottom face of the box body, which is erected projectingly from the tip end wall bottom face. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a powder press molding apparatus for pressing a ceramic granulated powder to form a ceramic substrate molded body in order to sinter the ceramic substrate molded body to produce a ceramic substrate.

Conventionally, ceramic substrates to be incorporated and used in various electronic devices, industrial devices, etc. are ceramics obtained by granulating a fine ceramic raw material powder such as alumina (Al ₂ O ₃ ) or aluminum nitride (AlN). Using the granulated powder, a ceramic substrate molded body having various shapes is formed with a mold for powder molding, and then fired. This ceramic substrate molded body is usually a sphere of about 80 microns in size by drying a solution obtained by mixing ceramic powder having sharp corners with sharp corners and a binder in water with a spray dryer. It may be formed using a granulated ceramic granulated powder. Alternatively, the ceramic substrate molded body may be formed by using a ceramic green sheet that is formed into a sheet shape by a doctor blade method or the like, in which a ceramic powder, a binder, or the like is mixed in a solvent. In general, when a ceramic green sheet is used, a conductive circuit is formed on a ceramic substrate molded body and can be electrically connected to a mounted semiconductor element or the like. It is a preferable form for forming such a package. On the other hand, when ceramic granulated powder is used, a ceramic substrate molded body insulating substrate having a complicated shape, a simple flat insulating substrate, a case having a small outer shape, a narrow bank width, and a deep recess is formed. It is a preferable form. In the case of forming a ceramic substrate molded body using this ceramic granulated powder, a powder press molding apparatus is conventionally used to form the ceramic substrate molded body.

  As shown in FIG. 3, a conventional powder press molding apparatus 50 is formed by press-molding a ceramic substrate molded body 51 (see FIGS. 4B to 4E) using a ceramic granulated powder 52. The apparatus has a molding die including a die 53, a lower punch 54, and an upper punch 55. Further, the conventional powder press molding apparatus 50 is attached so as to be interlocked with the movement of the mold, and has a feeder 56 for supplying the ceramic granulated powder 52 to the mold. Note that the conventional powder press molding apparatus 50 usually has a ground plate 57 attached to the tip wall surface of the feeder 56 to make the ceramic granulated powder 52 flush with the die 53.

  Here, the manufacturing method of the ceramic substrate molded body 51 using the conventional powder press molding apparatus 50 is demonstrated, referring FIG. 4 (A)-(E). As shown in FIG. 4A, in the powder press molding apparatus 50 described above, the wall surface of the through hole made of the outer dimensions of the ceramic substrate molded body 51 provided in the central portion of the die 53, and the lower part of the through hole from the bottom. A ceramic granulated powder 52 is filled in a space formed by the lower punch 54 inserted with the end face exposed. The ceramic granulated powder 52 filled in this space is dropped from the opening of the feeder 56 by moving the bottom surface of the outer periphery wall of the feeder 56 with the opening at the bottom in the horizontal direction on the die 53 (FIG. 4E )reference). At the same time, the ceramic granulated powder 52 restarts the feeder 56 while bringing the tip wall surface of the feeder 56 into contact with the upper surface of the die 53. As the feeder 56 is restarted, the ceramic granulated powder 52 rising from the upper surface of the die 53 is flush with the upper surface of the die 53 while being agitated by a grind plate 57 attached to the tip wall surface of the feeder 56. I have to. It should be noted that the upper punch 55 avoids the upper part to a position where it does not come into contact with the feeder 56 while the feeder 56 reciprocates.

  Next, as shown in FIG. 4 (B), the upper punch 55 is lowered and inserted into the through hole of the die 53 filled with the ceramic granulated powder 52, and the tip surface of the upper punch 55, The ceramic substrate molded body 51 is formed in the through hole by applying pressure to the tip surface of the lower punch 54. Note that the feeder 56 avoids laterally to a position where it does not contact the upper punch 55 while the upper punch 55 is lowered. As shown in FIG. 4C, the ceramic substrate molded body 51 in the through-hole of the die 53 remains sandwiched between the upper punch 55 and the lower punch 54, and the tip surface of the lower punch 54 is the die 53. The die 53 is lowered from the die 53 until it is flush with the upper surface. Note that the feeder 56 avoids sideways until the position where it does not come into contact with the upper punch 55 while the die 53 is lowered.

  Next, as shown in FIG. 4D, the ceramic substrate molded body 51 is taken out from the through hole of the die 53, and at the same time, the upper punch 55 and the die 53 are raised, and the upper punch 55 is moved to the ceramic substrate. While separating from the molded body 51, the ceramic substrate molded body 51 is supported by the upper peripheral edge of the through hole of the die 53 and peeled from the tip surface of the lower punch 54. The ceramic substrate molded body 51 can be supported by the upper peripheral edge of the through hole of the die 53 because the ceramic substrate molded body 51 is released from the die 53, the upper punch 55, and the lower punch 54, and expands. This is because it can be supported and placed on the upper peripheral edge of the through hole of the die 53 without being drawn into the die 53. At the same time, the feeder 56 starts the forward operation. Then, as shown in FIG. 4 (E), the feeder 56 pushes the ceramic substrate molded body 51 forward on the front surface of the tip wall, into the space formed by the through hole of the die 53 and the lower punch 54 from the bottom opening. The ceramic granulated powder 52 is dropped. Next, although not shown in the drawings, the ceramic substrate molded body 51 formed by the powder press molding apparatus 50 as described above is fired at a firing temperature and a firing atmosphere according to the firing conditions of each ceramic raw material. Is making.

In a conventional powder press molding apparatus, in order to make the packing density of the ceramic granulated powder dropped from the bottom opening of the feeder into the space formed by the through hole of the die and the lower punch, the ceramic structure is formed above the feeder. The thing which provided the pressurization mechanism in order to fill a granular powder uniformly is disclosed (for example, refer patent document 1).
In addition, in the conventional powder press molding apparatus, in order to reduce the filling variation of the ceramic granulated powder, the opening shape of the feeder is a circle or an ellipse, and the outer radius of the outer diameter of the ceramic substrate molded body that obtains the minimum radius is obtained. What is 1.1-2.5 times is disclosed (for example, refer patent document 2).

Japanese Utility Model Publication No. 6-592 Japanese Patent Laid-Open No. 7-117038

However, the conventional powder press molding apparatus as described above still has the following problems to be solved.
(1) In a conventional powder press molding apparatus, a grinding plate made of a metal plate such as brass is fixed to the front end wall surface of the feeder by screwing or the like, so that uneven wear on the contact end surface of the grinding plate with the die The ceramic granulated powder bites between the abutting end face of the scraped plate and the die, and the packing density of the ceramic granulated powder changes to cause defective external dimensions or deformation of the ceramic substrate. ing. In addition, since the conventional powder press molding apparatus is expensive to process the contact end face with the die of the feeder and repair the uneven wear of the chopped plate, the cost of the ceramic substrate molded body, and consequently the ceramic substrate, is increased. Yes.
(2) In the powder press molding apparatus disclosed in Japanese Utility Model Publication No. 6-592, it is difficult to determine the pressure timing of the pressure mechanism interlocked with the movement of the feeder. Uneven movement occurs, and on the contrary, the variation in filling density increases.
(3) The powder press molding apparatus disclosed in JP-A-7-117038 requires a feeder that matches each ceramic substrate molded body, and the center of the ceramic substrate molded body and the opening center of the feeder. Since the position needs to be accurately adjusted and the apparatus is expensive, the cost of the ceramic substrate molded body and, consequently, the ceramic substrate is increased.
This invention is made | formed in view of this situation, Comprising: It aims at providing the powder press molding apparatus which can make a packing density uniform and can produce an inexpensive ceramic substrate molded object.

  The powder press molding apparatus according to the present invention that meets the above-mentioned object is a flat die having a through hole having an outer dimension of a ceramic substrate molded body, and a lower punch that is fixedly inserted into the through hole from below. The upper punch and the wall surface of the through-hole have a die composed of an upper punch that can be inserted into and removed from the through-hole from above and movably from above. The ceramic granulated powder is filled in the space formed by sliding the ceramic granulated powder while sliding on the upper surface of the die, the ceramic granulated powder is filled in the space, and the ceramic granulated powder by the lower punch and upper punch In a powder press molding apparatus that forms a ceramic substrate compact by press-molding, the feeder consists of a box with an opening at the bottom, and the ceramic granulated powder charged into the space from the opening is diced. And from the interior of the front end wall bottom of the box to the upper surface flush to protrude from the pressed front end wall bottom through the pressing body having a level-off plate erected.

  In the powder press molding apparatus of the present invention, the feeder comprises a box having an opening at the bottom, and the tip wall of the box for making the ceramic granulated powder charged into the space from the opening flush with the upper surface of the die Since it has a grinding plate that is pressed from the inside of the bottom surface through a pressing body and protrudes from the bottom surface of the tip wall, the tip of the grinding plate comes into contact with the top surface of the die with uniform pressing force, In addition, the ceramic granulated powder can be prevented from being bitten, and the ceramic granulated powder can be uniformly packed to prevent the outer dimensions of the ceramic substrate after firing and defects such as deformation from occurring. In addition, this powder press molding apparatus can improve the yield of the ceramic substrate molded body to be produced, and it is not necessary to process the contact end surface with the die of the feeder or repair processing of uneven wear of the grinding plate, It is possible to prevent an increase in cost of the ceramic substrate molded body, and in turn the ceramic substrate.

(A), (B) is explanatory drawing of the powder press molding apparatus which concerns on one embodiment of this invention, respectively, and is explanatory drawing which looked at the feeder from the downward side. (A)-(E) are explanatory drawings of the manufacturing method of the ceramic substrate molded object by the same powder press molding apparatus, respectively. It is explanatory drawing of the conventional powder press molding apparatus. (A)-(E) are explanatory drawings of the manufacturing method of the ceramic substrate molded object by the same powder press molding apparatus, respectively.

Next, with reference to the accompanying drawings, embodiments for embodying the present invention will be described for understanding of the present invention.
As shown in FIGS. 1 (A) and 1 (B), a powder press molding apparatus 10 according to an embodiment of the present invention uses a ceramic substrate molded body 11 (see FIGS. 2 (B) to (E)) as a ceramic. This is an apparatus for press forming using the granulated powder 12. The powder press molding apparatus 10 has a die 14 provided with a through hole 13 having an outer dimension of a ceramic substrate molded body 11. Further, the powder press molding apparatus 10 has a lower punch 15 that is fitted into the through hole 13 of the die 14 from below and is inserted and fixed at a predetermined position. Furthermore, the powder press molding apparatus 10 has an upper punch 16 that can be inserted into and extracted from the through-hole 13 of the die 14 so as to be able to move upward and downward from above. In the powder press molding apparatus 10, the die 14, the lower punch 15, and the upper punch 16 constitute a powder press molding die. At the same time, the powder press molding apparatus 10 applies the ceramic granulated powder 12 to the space portion 17 formed by the upper surface of the lower punch 15 inserted into the through hole 13 and the wall surface of the through hole 13. It has a feeder 18 formed of brass or the like for filling while sliding on the upper surface of the die 14. In the powder press molding apparatus 10, after the ceramic granulated powder 12 is filled in the space portion 17, the ceramic granulated powder 12 is press molded by the lower punch 15 and the upper punch 16 to form the ceramic substrate molded body 11. It is like that.

The ceramic granulated powder 12 used in the above-mentioned powder press molding apparatus 10 is a ceramic raw material powder such as fine alumina (Al ₂ O ₃ ) or aluminum nitride (AlN) having a size of several microns, a binder, etc. A solution obtained by mixing a mixture of water with water and drying it with a spray dryer is used to produce spherical granules having a size of about 80 microns. The die used in the powder press molding apparatus 10 is a die in which the ceramic granulated powder 12 pressing surface portion of the upper punch 16 and the lower punch 15 and the upper punch 16 and the lower punch 15 are fitted and slid. A material in which the wall surfaces of 14 through-holes 13 are reinforced with a highly wear-resistant cemented carbide (WC: tungsten carbide) or the like is used.

  The feeder 18 used in the powder press molding apparatus 10 is made of a box having a bottom portion having a substantially rectangular opening 19. An upper portion of the feeder 18 serves as an inlet 20 for introducing the ceramic granulated powder 12 into the feeder 18, and a flexible hose 21 made of a rubber hose, a resin hose, or the like is attached to the inlet 20. . The ceramic granulated powder 12 introduced into the feeder 18 from the charging port 20 through the flexible hose 21 is formed by the upper surface of the lower punch 15 of the mold and the wall surface of the through hole 13 of the die 14 from the opening 19 of the feeder 18. Is inserted into the space 17 to be operated. And the ceramic granulated powder 12 thrown into the space part 17 is made to be flush with the upper surface of the die 14. In order to make the ceramic granulated powder 12 flush with the feeder 18, it is pressed from the inside of the bottom wall of the front end wall of the box through one or a plurality of pressing bodies 22 formed by a spring or the like. It has a grind plate 23 erected so as to protrude from the bottom surface. This scraping plate 23 is formed of a thin flat plate stainless steel plate or the like, and the pressing force of the pressing body 22 is always made uniform so that the end surface is brought into contact with the upper surface of the die 14 in a bridge shape in the space portion 17 and slides. By moving and grinding, the ceramic granulated powder 12 filled in the space portion 17 is flush with the upper surface of the die 14 so that the ceramic granulated powder 12 in the space portion 17 can be filled uniformly and accurately. Yes. The above-mentioned pressing body 23 is not limited to the position where it is attached, but normally, the pressing body 23 is provided at both ends of the grinding plate 23 so that the pressing force can be made uniform.

  The above-mentioned powder press molding apparatus 10 usually has a felt or the like for preventing wear between the metal of the feeder 18 and the die 14, scratches, etc. on the bottom surface of the outer peripheral wall other than the bottom surface of the tip wall of the feeder 18. The cushion material 24 which consists of is affixed. Further, the above powder press molding apparatus 10 is made of rubber, plastic or the like on the front surface of the front end wall of the feeder 18 in order to accurately extrude the ceramic substrate molded body 11 produced and taken out from the mold at the front end of the feeder 18. A guide plate 25 is attached.

Here, a manufacturing method of the ceramic substrate molded body 11 using the powder press molding apparatus 10 will be described with reference to FIGS.
In this powder press molding apparatus 10, for example, ceramic granulated powder 12 made of alumina (Al ₂ O ₃ ), aluminum nitride (AlN), or the like, which is an example of ceramic, is used to form a ceramic substrate molded body 11. It has been. The ceramic substrate molded body 11 produced by the above-described powder press molding apparatus 10 has a high temperature (for example, about 1550 ° C. in the air in the case of alumina, and about nitrogen in the atmosphere in the case of aluminum nitride). The ceramic substrate is manufactured by firing at about 1700 ° C.

  As shown in FIG. 2A, the powder press molding apparatus 10 is formed by the upper surface of the lower punch 15 inserted up to the middle of the through hole 13 of the die 14 and the wall surface of the through hole 13. The space 17 is filled with the ceramic granulated powder 12. The space 17 is filled in a pile while the feeder 18 is moved forward on the die 14 in the horizontal direction and the ceramic granulated powder 12 is dropped from the lower opening 19 of the feeder 18 (see FIG. 2E). ). Further, in the powder press molding apparatus 10, the ceramic granulated powder 12 is pressed through the pressing body 22 from the inside of the bottom surface of the front end wall of the feeder 18 box by the backward movement in which the feeder 18 returns to the original position. The upper surface of the die 14 is flush with the upper surface of the die 14 by agitation with a scraping plate 23 that is erected so as to protrude from the bottom surface and pressed against the upper surface of the die 14.

  When the ceramic granulated powder 12 is filled into the space by the feeder 18, the ceramic granulated powder 12 is a spherical granulated powder, and therefore flows into the space at an angle of repose to make the packing density uniform. The ceramic granulated powder 12 swelled from the upper surface of the die 14 is returned to the feeder 18 and agitated by the grinding plate 23 pressed by the pressing body 22 to be flush with the upper surface of the die 14. be able to. Further, while the feeder 18 reciprocates and the ceramic granulated powder 12 is filled in the space of the die 14, the upper punch 16 stops at an upper position where it does not get in the way to avoid collision with the feeder 18. .

  Next, as shown in FIG. 2 (B), in this powder press molding apparatus 10, the upper punch 16 is lowered and inserted into the through-hole 13 while being fitted to the wall surface of the through-hole 13 of the die 14, so that the space The ceramic granulated powder 12 in the portion 17 is pressed by an upper punch 16 and a stationary lower punch 15. In the powder press molding apparatus 10, the ceramic substrate molded body 11 is produced in which spherical granulated powder of the ceramic granulated powder 12 is crushed and hardened in the through holes 13 of the die 14. Note that the feeder 18 avoids laterally to a position where it does not contact the upper punch 16 while the upper punch 16 is lowered.

  Next, as shown in FIG. 2C, in this powder press molding apparatus 10, the die 14 is kept sandwiched between the upper punch 16 and the lower punch 15 while the lower punch 15 is stationary. Is lowered until the upper surface of the die 14 and the tip surface of the lower punch 15 are flush with each other. In the powder press molding apparatus 10, the ceramic substrate molded body 11 is taken out from the through hole 13 of the die 14 while being sandwiched between the upper punch 16 and the lower punch 15. Note that the feeder 18 avoids sideways to a position where it does not come into contact with the upper punch 16 while the die 14 is lowered.

  Next, as shown in FIG. 2 (D), in this powder press molding apparatus 10, the upper punch 16 is lifted away from the ceramic substrate molded body 11 while the lower punch 15 remains stationary, and the die 14 is moved. The ceramic substrate molded body 11 is lifted while being supported by the upper peripheral edge of the through hole 13 so as to be peeled off from the lower punch 15. In addition to releasing the die 14 from the through hole 13, the ceramic substrate molded body 11 is released from the outer peripheral portion by releasing the upper surface side by raising the upper punch 16 and releasing from the lower punch 15 by lifting the die 14. The restraint is released, and expansion can be generated. Thus, the ceramic substrate molded body 11 can be supported and taken out by being placed on the upper peripheral edge of the die 14 without being drawn into the through hole 13 of the die 14. The expansion of the ceramic substrate molded body 11 is preferably about 0.2 to 0.5%, and by this appropriate expansion, the ceramic substrate molded body 11 is expanded without being broken while being taken out from the inner wall of the die 14, and the ceramic substrate molded body. 11 can be reliably taken out to the upper edge of the die 14 and can be reliably pushed onto the die 14 at the tip of the feeder 18 without dropping into the gap between the die 14 and the lower punch 15. Note that the feeder 18 starts the forward operation in the horizontal direction simultaneously with the above movement.

  Next, as shown in FIG. 2 (E), in the powder press molding apparatus 10, the feeder 18 further moves forward to bring the guide plate 25 provided at the tip into contact with the ceramic substrate molded body 11 as a die. 14 is pushed out to the upper surface end side. At the same time, the die 14 is further raised, and a space portion 17 for forming the next ceramic substrate molded body 11 is formed in the die 14. The space 17 is filled with the ceramic granulated powder 12 that flows in through the flexible hose 21 provided at the inlet 20 of the feeder 18 from the opening 19 provided at the lower portion of the feeder 18. Thereafter, the ceramic substrate molded body 11 is continuously produced by repeating the return to the state described with reference to FIG.

  Although the ceramic substrate molded body 11 is not shown, the ceramic granulated powder 12 is about 1550 ° C. in the atmosphere when the ceramic granulated powder 12 is, for example, alumina, and about 1700 ° C. in a nitrogen atmosphere when the ceramic granulated powder 12 is aluminum nitride. The ceramic substrate is fired at a temperature of

  The inventor produced the ceramic substrate molded body of the example by using the powder press molding apparatus according to the present invention and the ceramic substrate molded body of the conventional example by using the conventional powder press molding apparatus, respectively. The weights were measured and the variations were compared. As a raw material, ceramic granulated powder made of alumina was used. The mold was set so that the outer dimension of the space portion was 50 mm × 50 mm, and the depth of the space portion into which about 10 g of the ceramic granulated powder entered. And after filling ceramic granulated powder into each space part with each feeder, it pressed and formed the ceramic substrate molded object which consists of a board | plate body. The results are shown in Table 1.

  It can be confirmed that the ceramic substrate molded body of the example reduces the weight variation by about 50% compared to the ceramic substrate molded body of the conventional example, and the influence on the dimensions is reduced by grinding with a ground plate always having a constant pressing force. As a result, it was confirmed that the dimensional accuracy could be improved.

  The powder press molding apparatus of the present invention can be used as an apparatus that can produce a product for electronic parts with high dimensional accuracy at low cost with less maintenance.

  10: Powder press molding apparatus, 11: Ceramic substrate molded body, 12: Ceramic granulated powder, 13: Through hole, 14: Die, 15: Lower punch, 16: Upper punch, 17: Space part, 18: Feeder, 19 : Opening, 20: Loading port, 21: Flexible hose, 22: Pressing body, 23: Grinding plate, 24: Cushion material, 25: Guide plate

Claims (1)

A flat plate-shaped die provided with a through-hole having an outer dimension of the ceramic substrate molded body, a lower punch that is inserted into the through-hole from below and fixed at a predetermined position, and an upper side of the through-hole from above And a space formed by the upper surface of the lower punch and the wall surface of the through hole in a state of being inserted to the middle of the through hole. The ceramic granulated powder is filled with the ceramic granulated powder while sliding on the upper surface of the die, the ceramic granulated powder is filled in the space portion, and the ceramic granulated powder is filled with the lower punch and the upper punch. In a powder press molding apparatus for forming a ceramic substrate molded body by press molding,
The feeder comprises a box having an opening at the bottom, and from the inside of the bottom wall of the front end wall of the box for making the ceramic granulated powder charged into the space through the opening flush with the upper surface of the die. A powder press molding apparatus, comprising: a grinding plate that is pressed through a pressing body and is erected so as to protrude from the bottom surface of the tip wall.

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