JP4345971B2 - Manufacturing method of ceramic package - Google Patents

Description

  The present invention relates to a ceramic package in which an electronic component element is mounted in a cavity formed by a ceramic base and a ceramic frame, and a lid is joined to the upper surface of the ceramic frame to hermetically seal the electronic component element. It relates to the manufacturing method.

  In recent years, ceramic packages for housing electronic component elements such as semiconductor elements, crystal resonators, and piezoelectric elements have become smaller and more reliable for devices equipped with electronic component elements, such as mobile phones and personal computers. In response to demands such as these, there is an urgent need to respond to lighter, lighter, smaller and higher reliability. In order to cope with this, a package made of a ceramic made of a laminate of a ceramic base body and a ceramic frame body with high hermetic reliability is used. In this ceramic package, an electronic component element is housed, and a frame-shaped metal frame bonded to a bonding conductor pattern formed on the upper surface side of the frame-shaped ceramic frame body or an upper surface side of the ceramic frame body A metal lid is bonded to the frame-shaped bonding conductor pattern via a brazing material, and the electronic component element is hermetically sealed. The ceramic package on which the electronic component element is mounted is bonded to a board or the like via solder or the like with an external connection terminal pad which is a conductor pattern on the lower surface side of the package.

  With reference to FIGS. 4A to 4C, a ceramic package 50 manufactured by a typical conventional ceramic package manufacturing method will be described. 4A is a perspective view of the upper surface side of the ceramic package 50, FIG. 4B is a perspective view of the lower surface side, FIG. 4C is a longitudinal sectional view taken along line YY ′, and ZZ. It is a line longitudinal cross-sectional view. As shown in FIGS. 4A and 4B, the ceramic package 50 is formed by laminating one or a plurality of ceramic base bodies 51 and one or a plurality of frame-shaped ceramic frame bodies 52. The ceramic package 50 includes a cavity 53 for mounting an electronic component element such as a semiconductor element or a crystal resonator, the upper surface of the central portion of the ceramic base 51 as a bottom surface, and the inner peripheral wall surface of the ceramic frame 52. Is formed by. In order to form the ceramic substrate 51 and the ceramic frame 52, for example, a ceramic green sheet made of alumina or the like is screened using a conductive paste made of a refractory metal such as W (tungsten) or Mo (molybdenum). The printed pattern is formed with a conductor pattern on the surface, a via 54 filling a through-hole provided in advance, and a through-hole conductor film 55 on the wall surface of the through-hole. On the upper surface side of this conductor pattern, a bonding conductor pattern 56 for bonding a lid directly or via a metal frame, a connecting conductor pattern 57 for connecting to an electronic component element, etc. There is. On the lower surface side, there are external connection terminal pads 58 for bonding to a board or the like.

  As shown in FIG. 4C, in order to connect the bonding conductor pattern 56 formed on the upper surface of the ceramic frame 52 and the external connection terminal pad 58, a via 54 provided in the ceramic frame 52, It is connected to the external connection terminal pad 58 on the lower surface side through the through-hole conductor film 55 via the conductor pattern. Alternatively, the bonding conductor pattern 56 is connected to the external connection terminal pad 58 on the lower surface side by a via 54 provided in communication with the ceramic frame 52 and the ceramic base 51. The connection conductor pattern 57 in the cavity 53 is connected to the external connection terminal pad 58 through the through-hole conductor film 55 connected to the conductor pattern. The ceramic green sheets of the ceramic base 51 and the ceramic frame 52 are laminated to form a laminated body, and after connecting the conductor pattern, the via 54, and the through-hole conductor film 55, respectively, A refractory metal is simultaneously fired to form a fired body. Furthermore, the Ni plating film and the Au plating film are applied on the conductor pattern exposed on the outer surface of the fired body to produce the ceramic package 50.

However, according to the conventional ceramic package and the manufacturing method thereof, the frame width of the ceramic frame is reduced as the apparatus is downsized, and the bonding is performed when the lid is bonded to the bonding conductor pattern formed on the ceramic frame. Since the width is reduced, it has become difficult to form a via in the bonding conductor pattern. Therefore, the ceramic package can be connected to the bonding conductor pattern by providing a conductor pattern in the cutout portion formed on the ceramic base, the outer side surface of the ceramic frame, or the inner peripheral side surface of the ceramic frame. At the same time, it has been proposed to prevent the solder from rising to the bonding conductor pattern on the upper surface side and to electrically connect the bonding conductor pattern and the external connection terminal pad on the lower surface side (for example, patents). Reference 1 and Patent Reference 2).
Japanese Patent No. 2948998 Japanese Patent No. 3415762

However, the conventional ceramic package manufacturing method as described above still has the following problems to be solved.
(1) Providing cutouts on the outer side surface and inner peripheral side surface of the ceramic frame body reduces the width of the bonding conductor pattern formed on the ceramic frame body, so There is a problem with hermetic reliability.
(2) In order to form a through-hole conductor film in the cutout portion of the ceramic substrate or ceramic frame, the through-hole conductor film is formed on the wall surface of the through-hole formed in the ceramic green sheet, and then the through-hole is traversed. However, it takes time and man-hours to form this, which increases the cost of the ceramic package.
(3) The size of the cutout portion formed on the side surface of the ceramic base or the ceramic frame is made smaller on the upper surface side on which the bonding conductor pattern is formed than on the lower surface side, thereby reducing the pattern width of the bonding conductor pattern. In the enlarged ceramic package, a through-hole conductor film is formed in the notch where the upper and lower sides of the package communicate, so that the brazing material used when joining the lid is connected to the external connection terminal via the through-hole conductor film. It flows into the pad and the brazing material at the joint becomes insufficient, resulting in insufficient joint strength. In addition, when the package is attached to the board or the like via a bonding material such as solder with the external connection terminal pad, since a brazing material film is formed on the surface of the external connection terminal pad, there is a problem in bonding reliability. Furthermore, when the package is attached to a board or the like via a bonding material such as solder with an external connection terminal pad, the bonding material flows into the lid body through the through-hole conductor film, so the volume of the bonding material at the joint is insufficient. However, the bonding strength is insufficient.
(4) The size of the ceramic frame is reduced along with the downsizing of the device, making it difficult to form a through hole for the via in the ceramic frame. The conductive pattern for bonding on the upper surface side and the external connection terminal pad on the lower surface side are electrically connected to each other because the flow of brazing material when the lid is bonded and the bonding material when mounted on a board or the like The flow can be dammed by the second ceramic frame, but since a two-layer ceramic frame is required, there is a limit to the lightness and smallness of the package. Moreover, when it consists of a combination of a single-layer ceramic frame and a flat plate, it is difficult to implement.
The present invention has been made in view of such circumstances, and can cope with light and thin packages, and has a high hermetic reliability by increasing the width of a bonding conductor pattern, and further, brazing material and bonding material It is an object of the present invention to provide a method for manufacturing a ceramic package that can prevent the flow of heat and increase the bonding reliability.

The method for manufacturing a ceramic package according to the present invention that meets the above-described object is a laminate of one or more plate-shaped ceramic bases and one or more frame-shaped ceramic frames having a rectangular hole in the center. In the method for manufacturing a ceramic package, the conductive pattern is electrically connected to the upper surface of the uppermost layer of the ceramic frame body and communicates with a part of the inner peripheral wall of all layers of the ceramic frame body. Protrusions that are substantially the same as the thickness of the ceramic frame on which the rectangular holes of the ceramic frame can be inserted are provided on the chuck plate having suction holes that can be sucked from below. placing a respective ceramic frame body on the chuck plate while inserting the rectangular hole of the frame body, intake a conductive paste suction hole portions of the screen printing plate of the mesh structure from the top surface in contact with To be formed by screen printing.

The process according to claim 1 Symbol mounting ceramic package with conductive top layer of electrically been a bonding conductor pattern formed on the upper surface of the insulating wall, a portion of the inner peripheral wall of all layers of the insulating wall The conductive film that communicates with each other is provided with a convex portion substantially equal to the thickness of the ceramic frame body on which the rectangular hole of the ceramic frame body can be inserted on the chuck plate having a suction hole that can be sucked from below. Screen printing in which each ceramic frame is placed on the chuck plate while inserting a rectangular hole in the ceramic frame, and a screen printing plate with a mesh structure is brought into contact with the top surface to suck the conductive paste through the suction hole. Therefore, the conductive pattern formed on the upper surface of the ceramic frame and the lower surface of the ceramic base is electrically connected, and at the same time, the brazing material flow and the bonding material flow are prevented. It can provide a manufacturing method that can. In addition, it is possible to normally create a pool of bonding material (meniscus), to firmly bond the package to a board, etc., and to check the state of the bonded portion by visual inspection, so that the apparatus has high bonding reliability. A manufacturing method can be provided. In addition, a conductive film provided on the inner peripheral wall surface of the ceramic frame body provides electrical continuity, the width of the bonding conductor pattern can be widened, and airtight reliability can be increased. Can be provided. Furthermore, since a ceramic frame having a single layer can be used, a method for manufacturing a light, thin and small package can be provided. In addition, it is possible to increase the suction force from the suction holes provided in the chuck plate, and to provide a package manufacturing method that stably forms a conductor film on a part of the inner peripheral wall of the ceramic frame.

Subsequently, the best mode for carrying out the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention.
Here, FIGS. 1A to 1C are respectively a perspective view of the upper surface side, a perspective view of the lower surface side of the ceramic package manufactured by the method of manufacturing a ceramic package according to the embodiment of the present invention, and AA. 'Line longitudinal sectional view and BB' longitudinal sectional view, FIGS. 2 (A) and 2 (B) are explanatory views of the manufacturing method of the ceramic package, and FIGS. 3 (A) and 3 (B) are the ceramic package, respectively. It is explanatory drawing of other manufacturing methods.

  As shown in FIGS. 1A to 1C, a ceramic package 10 manufactured by a method for manufacturing a ceramic package according to an embodiment of the present invention includes one or a plurality of substantially rectangular flat plate ceramic substrates. 11 and a laminated body of one or more frame-shaped ceramic frame bodies 12 having an opening in the center (in FIG. 1, it is composed of two ceramic base bodies 11 and one ceramic frame body 12). It is configured. An electronic component element 14 such as a semiconductor element, a crystal resonator, or a piezoelectric element can be mounted on the cavity 13 formed by the bottom of the ceramic base 11 and the inner peripheral wall of the ceramic frame 12. The ceramic package 10 is electrically connected to the bonding conductor pattern 15 formed on the upper surface of the uppermost ceramic frame 12, and communicates with a part of the inner peripheral wall of all layers of the ceramic frame 15. A conductor film 16 is provided directly on the wall surface. The conductor film 16 is electrically connected to the external connection terminal pad 19 through a conductor pattern and a through-hole conductor film 18 on the surface of the notch 17 formed on a part of the outer peripheral side surface of the ceramic substrate 11. It is in a state.

  After the electronic component element 14 is mounted on the connecting conductor pattern 20 provided on the upper surface of the ceramic substrate 11 in the cavity portion 13, the bonding conductor pattern 15 is joined by the metal lid 21 and is then inside the cavity portion 13. Is provided for hermetically sealing. The connecting conductor pattern 20 is a via 22 provided through the ceramic substrate 11, a through pattern on the surface of the cutout portion 17 formed on a part of the conductor pattern or the outer peripheral side surface of the ceramic substrate 11 different from the above. It is electrically connected to an external connection terminal pad 19 different from the above via the hole conductor film 18 or the like.

  In addition, a frame-shaped metal frame for enabling the electronic component element 14 to be surrounded is bonded to the bonding conductor pattern 15, and the metal frame and the metal lid 21 may be bonded. Further, the bonding conductor pattern 15 is connected to the external connection terminal pad 19 and used as an electrode terminal because the external connection terminal pad 19 is electrically connected to the bonding conductor pattern 15 in a metal frame, This is also because the metal lid 21 can be used as a ground for an electric circuit. Furthermore, the through-hole conductor film 18 formed on the side surface of the ceramic substrate 11 forms a meniscus for firmly bonding the external connection terminal pad 19 to the board or the like when the external connection terminal pad 19 is joined to the board or the like via solder or the like. Are also used.

  Next, a method for manufacturing the ceramic package 10 according to one embodiment of the present invention will be described with reference to FIGS. Here, FIG. 2A is a partially enlarged plan view when a conductor film is formed on the ceramic green sheet for the ceramic frame 12, and FIG. 2B is a screen printing state of the portion C in FIG. FIG.

  The ceramic base material used for the ceramic substrate 11 and the ceramic frame 12 includes alumina, aluminum nitride, low-temperature fired ceramic, and the like, and the material is not particularly limited. For example, when using alumina as the ceramic substrate, first, a powder obtained by adding an appropriate amount of a sintering aid such as magnesia, silica, calcia to aluminum oxide powder, a plasticizer such as dioctiphthalate, an acrylic resin, etc. And a solvent such as toluene, xylene, alcohols, etc. are added, kneaded sufficiently and defoamed to prepare a slurry having a viscosity of 2000 to 40000 cps, and fired by a doctor blade method or the like to have a desired thickness, for example, 0. After drying into a sheet shape so as to be 12 mm, the ceramic green sheet is formed by cutting into a rectangular shape having a desired size. The ceramic green sheet is formed so that a large number of ceramic packages 10 are arranged, and a dividing line is formed for dividing into individual pieces that are formed in advance after forming the laminate, and the dividing line is formed after firing. The individual packages are manufactured by dividing into individual pieces. When the metal frame is bonded to the bonding conductor pattern 15 of the ceramic frame 12, the metal base of the metal frame is, for example, a ceramic base 11 such as KV or 42 alloy, or the ceramic frame 12 A metal plate having a thermal expansion coefficient approximating a frame shape by etching or punching press preparation is prepared.

  As shown in FIGS. 2 (A) and 2 (B), in order to produce the ceramic frame 12, first, a through-hole conductor 18 is formed in the notch 17 as necessary in the ceramic green sheet. A circular through hole or a rectangular hole 23 for forming the cavity portion 13 is formed using a punching press or a punching machine. The conductive paste 24 for forming the conductive pattern on the ceramic green sheet is made of, for example, W or Mo as the conductive metal when the ceramic green sheet is fired at a high temperature such as alumina or aluminum nitride. A refractory metal is used to make a paste that can be screen-printed. Then, on the upper surface of the ceramic green sheet for the ceramic frame 12 which is the uppermost layer, this ceramic green sheet is placed on the chuck plate 25 of the screen printing machine, and the above-mentioned conductor paste 24 is used for bonding. The conductor pattern 15 is formed by screen printing. Further, a part of the wall surface of the rectangular hole 23 of the ceramic green sheet for each ceramic frame 12 is electrically connected to the bonding conductor pattern 15, and the ceramic green sheet for each ceramic frame 12. The conductor film 16 communicating at the same position on the wall surface is directly formed on the wall surface.

  The conductive film 16 is formed by placing a ceramic green sheet for each ceramic frame 12 on a chuck plate 25 having a suction hole 26 that can be sucked from below the screen printing machine, and screening the mesh structure from above. Screen printing is performed by bringing the printing plate 27 into contact and sucking the conductive paste 24 through the suction holes 26 while moving the conductive paste 24 with the squeegee 28 on the screen printing plate 27. Note that the bonding conductor pattern 15 and the conductor film 16 may be formed by screen printing at a time, or may be separately performed. Moreover, although the formation position of the conductor film 16 was shown by providing in the corner part of the rectangular hole 23 in the figure, a position is not limited and may be provided in any position.

  Next, in order to fabricate the ceramic substrate 11, as in the case of the ceramic frame 12, first, through each ceramic green sheet, if necessary, a through hole for the notch portion 17 or a through hole for the via 22. Holes and the like are formed using a punching press or a punching machine. Next, using the same conductive paste 24 as in the case of the ceramic frame 12, the connection conductor pattern 20, the external connection terminal pad 19, and the via 22 provided in each ceramic green sheet, or the through-hole conductor film 18 is connected. A conductor pattern or the like is formed by screen printing. Furthermore, a through-hole conductor film 18 is formed by screen printing on the wall surface of the through hole for the cutout portion 17 of the ceramic green sheet for the required ceramic substrate 11. Further, the through hole for the via 22 of the ceramic green sheet for the ceramic substrate 11 is filled with the conductive paste 24 by screen printing.

  Next, each ceramic green sheet is overlaid and pressed while applying temperature to form a laminate. Since a large number of packages are formed as an aggregate in this stacked body, a dividing groove for dividing is formed in order to form a package consisting of individual pieces. Next, the laminated ceramic green sheets and the dried conductor paste 24 are simultaneously fired in a firing furnace to form a fired body. As a result, a package of a large number of aggregates made of fired bodies is formed. Next, in this fired package, Ni plating is applied to all conductor patterns exposed on the outer surface, and then Au plating is performed to form a ceramic package 10 composed of a large number of aggregates. . In addition, when joining a metal frame on the conductor pattern 15 for joining, after plating Ni on all the conductor patterns exposed to an outer surface, it is metal via brazing materials, such as Ag-Cu solder | pewter. The frame body is placed, heated and brazed and joined, and then Ni plating and Au plating are performed on all the conductor patterns exposed on the outer surface including the metal frame body, thereby forming a ceramic composed of a large number of aggregates. A package 10 is formed. Next, the ceramic package 10 made up of a large number of aggregates is divided by dividing grooves to form the ceramic package 10 made up of individual pieces. The ceramic package 10 made up of individual pieces is divided into individual pieces after the electronic component element 14 is mounted on the ceramic package 10 in a large number of aggregates and hermetically sealed with a metal lid 21. Alternatively, after being divided into individual pieces, the electronic component element 14 is mounted and hermetically sealed with a metal lid 21.

  Next, another method for manufacturing the ceramic package 10 according to the embodiment of the present invention will be described with reference to FIGS. Here, FIG. 3A is a partially enlarged plan view when a conductor film is formed on the ceramic green sheet for the ceramic frame 12, and FIG. 3B is a screen printing state of the D portion in FIG. 3A. FIG.

  The ceramic base material 11 used in another method for manufacturing the ceramic package 10 according to the embodiment of the present invention and the ceramic base material for the ceramic frame 12 are the same ceramic base materials as described above. . Moreover, the thing similar to the said case is used also for the conductor paste 24 used for a ceramic base material. Furthermore, the same metal substrate as in the above case is also used for the metal frame when the metal frame is bonded to the bonding conductor pattern 15 of the ceramic frame 12.

  As shown in FIGS. 3 (A) and 3 (B), in order to produce the ceramic frame 12, a circular through-hole for forming the notch 17 in the ceramic green sheet as described above. 23 or a rectangular hole 23 for forming the cavity portion 13 is formed by using a punching press or a punching machine. Then, in order to place the ceramic green sheet for the ceramic frame 12 on the chuck plate 25 of the screen printing machine and form a conductor pattern using the conductor paste 24, a rectangular pattern is formed on the chuck plate 25. The shape hole 23 can be inserted, and a convex portion 29 having a thickness substantially equal to the thickness of the ceramic frame 12 is provided. On the upper surface of the ceramic green sheet for the ceramic frame 12 that is the uppermost layer, the ceramic hole for the ceramic frame 12 is inserted while the rectangular holes 23 of the ceramic green sheet are inserted into the convex portions 29 of the chuck plate 25 of the screen printing machine. A green sheet is placed on the chuck plate 25, and the conductor pattern 15 for bonding is formed by screen printing using the conductor paste 24. Further, a part of the wall surface of the rectangular hole 23 of the ceramic green sheet for each ceramic frame 12 is electrically connected to the bonding conductor pattern 15, and the ceramic green sheet for each ceramic frame 12. The conductor film 16 communicating at the same position on the wall surface is directly formed on the wall surface.

  The conductive film 16 is formed by a ceramic green for each ceramic frame 12 on the chuck plate 25 formed by providing a suction hole 26 that can be sucked from the lower side of the screen printing machine with a notch in the convex portion 29. Screen printing in which a sheet is placed, the screen printing plate 27 having a mesh structure is brought into contact with the upper surface, and the conductive paste 24 is sucked by the suction holes 26 while the conductive paste 24 is moved by the squeegee 28 on the screen printing plate 27 Is going on. In the formation of the conductor film 16 by this method, since the suction force from the suction hole 26 can be increased, the conductor film 16 can be formed stably. Note that the bonding conductor pattern 15 and the conductor film 16 may be formed by screen printing at a time using the same chuck plate 25 or may be separately performed. Moreover, although the formation position of the conductor film 16 was shown by providing in the corner part of the rectangular hole 23 in the figure, a position is not limited and may be provided in any position.

  Next, the steps after the formation of the respective laminates of ceramic green sheets are performed in the same manner as described above, and the ceramic package 10 is manufactured.

  The ceramic package of the present invention mounts an electronic component element such as a semiconductor element or a crystal resonator, and is small and requires high reliability. For example, an electronic device such as a mobile phone or a notebook computer It can be used by being incorporated in.

(A)-(C) are the perspective views of the upper surface side of a ceramic package produced by the manufacturing method of the ceramic package which concerns on one embodiment of this invention, the perspective view of a lower surface side, and AA 'line longitudinal cross-sectional view, respectively. And BB ′ line longitudinal cross-sectional view. (A), (B) is explanatory drawing of the manufacturing method of the same ceramic package, respectively. (A), (B) is explanatory drawing of the manufacturing method of the same ceramic package, respectively. (A)-(C) is the perspective view of the upper surface side of the ceramic package produced with the manufacturing method of the conventional ceramic package, the perspective view of a lower surface side, a YY 'line longitudinal cross-sectional view, and a ZZ' line longitudinal section, respectively. FIG.

Explanation of symbols

  10: Ceramic package, 11: Ceramic substrate, 12: Ceramic frame, 13: Cavity part, 14: Electronic component element, 15: Conductive pattern for joining, 16: Conductive film, 17: Notch part, 18: Through-hole conductor Membrane, 19: External connection terminal pad, 20: Connection conductor pattern, 21: Metal lid, 22: Via, 23: Rectangular hole, 24: Conductive paste, 25: Chuck plate, 26: Suction hole, 27: Screen printing plate, 28: Squeegee, 29: Convex

Claims (1)

In a method for manufacturing a ceramic package constituted by a laminate of one or more plate-shaped ceramic base bodies and one or more frame-shaped ceramic frame bodies having a rectangular hole in the center,
The conductor film that is electrically connected to the bonding conductor pattern formed on the upper surface of the uppermost layer of the ceramic frame and communicates with a part of the inner peripheral wall of all the layers of the ceramic frame is sucked from below. Protrusions having substantially the same thickness as the ceramic frame body into which the rectangular holes of the ceramic frame body can be inserted are provided on a chuck plate having a possible suction hole, and the projecting portion of the ceramic frame body is provided on the convex portion. Formed by screen printing in which each ceramic frame is placed on the chuck plate while inserting a rectangular hole, and a screen printing plate having a mesh structure is brought into contact with the upper surface to suck the conductive paste through the suction hole portion. A method for manufacturing a ceramic package, comprising:

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