JP2008211062A - Laminated ceramic package and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated ceramic package that achieves further reduction in man-hour than a conventional one, and its manufacturing method. <P>SOLUTION: The laminated ceramic package is composed of a laminated ceramic substrate 1 in which a cavity 10 is formed on its surface, a cap 2 joined to the surface of the laminated ceramic substrate 1, and an electronic device 3 stored in the cavity 10 of the laminated ceramic substrate 1. The rear face of the laminated ceramic substrate 1 has a plurality of external electrodes 7 connected with the electronic device 3 through each conductor filling part 6. The electronic device 3 is arranged on the inner face of the cap 2. A plurality of internal electrodes 5 are interposed between opposing faces of the laminated ceramic substrate 1 and the cap 2 so as to connect the electronic device 3 with each conductor filling part 6 of the laminated ceramic substrate 1. A metal sealing part 4 is also interposed between the opposing faces of the laminated ceramic substrate and the cap so as to seal a space formed between the laminated ceramic substrate 1 and the cap 2 while surrounding the internal electrodes 5. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a multilayer ceramic package in which an electronic device is accommodated in a cavity formed between a multilayer ceramic substrate and a cap, and a method for manufacturing the same.

Conventionally, as shown in FIG. 13C, a multilayer ceramic substrate (100) having a cavity (104) recessed on the surface, and a multilayer ceramic substrate (100) covering the cavity (104) of the multilayer ceramic substrate (100). A multilayer ceramic package comprising a cap (101) bonded to the surface of the ceramic substrate and an electronic device (102) such as a surface acoustic wave element housed in a cavity (104) of the multilayer ceramic substrate (100) is known. ing.
In the multilayer ceramic package, a plurality of external electrodes (not shown) electrically connected to the electronic device (102) are formed on the back surface of the multilayer ceramic substrate (100), and the multilayer ceramic package is disposed on the circuit board. Surface mounting is possible.

In the production of a conventional multilayer ceramic package, as shown in FIG. 13A, first, a multilayer ceramic substrate (100) having a cavity (104) recessed on the surface is produced, and the multilayer ceramic substrate (100) is manufactured. The electronic device (102) is accommodated in the cavity (104), and the electronic device (102) is fixed to the multilayer ceramic substrate (100) with an adhesive (105) (die bonding step).
Next, as shown in FIG. 13B, the plurality of terminal portions of the electronic device (102) are connected to the plurality of electrode portions formed on the surface of the multilayer ceramic substrate (100) using wires (103) (see FIG. 13B). Wire bonding process).
Finally, as shown in FIG. 13 (c), a cap (101) is joined to the surface of the multilayer ceramic substrate (100) so as to cover the cavity (104), and the multilayer ceramic substrate (100) and the cap (101) are joined. The space formed therebetween is sealed (sealing step).
JP-A-9-116377 [H03H9 / 25]

However, in the conventional multilayer ceramic package, since it is necessary to perform the sealing process shown in FIG. 13C after the wire bonding process shown in FIG. There was a problem.
SUMMARY OF THE INVENTION An object of the present invention is to provide a multilayer ceramic package and a method for manufacturing the same, which can reduce the number of steps compared to the conventional art.

A multilayer ceramic package according to the present invention includes a multilayer ceramic substrate (1) having a cavity (10) recessed on a surface thereof, and a multilayer ceramic substrate (1) covering the cavity (10) of the multilayer ceramic substrate (1). It comprises a cap (2) bonded to the surface and an electronic device (3) accommodated in the cavity (10) of the multilayer ceramic substrate (1). The electronic device is disposed on the back surface of the multilayer ceramic substrate (1). A plurality of external electrodes (7) connected to (3) via conductive paths are formed.
Here, the electronic device (3) is disposed on the inner surface of the cap (2), and the electronic device (3) is disposed between the opposing surfaces of the multilayer ceramic substrate (1) and the cap (2). (1) A plurality of internal electrodes (5) for connecting to the conductive path in the space are interposed, and the internal electrodes (5) are surrounded to be interposed between the multilayer ceramic substrate (1) and the cap (2). A metal sealing portion (4) for sealing the formed space is interposed.
The plurality of internal electrodes (5) are specifically made of the same metal as the sealing metal forming the sealing portion (4).

The manufacturing method of the multilayer ceramic package of the present invention described above,
A multilayer ceramic substrate (1) having a cap (2) having an electronic device (3) on the inner surface, a cavity (10) recessed in the front surface, and a plurality of external electrodes (7) formed on the rear surface A first step of producing
By joining and integrating the multilayer ceramic substrate (1) and the cap (2), the electronic device (3) of the cap (2) is electrically connected to the plurality of external electrodes (7) of the multilayer ceramic substrate (1). A second step, and in the first step, the surface of the multilayer ceramic substrate (1) is made to correspond to the plurality of electrode pads formed on the inner surface of the cap (2), and the plurality of external electrodes ( 7) A plurality of connection metal pads (68) connected to the conductive path via the conductive path are formed. In the second step, each connection metal pad (68) of the multilayer ceramic substrate (1) and each electrode pad of the cap (2) are formed. And a sealing metal frame portion surrounding and surrounding the plurality of connection metal pads (68) between the facing surfaces of the multilayer ceramic substrate (1) and the cap (2), The connecting metal pad (68) and the sealing metal frame are once melted and then solidified. Characterized in that the applied.

  In the manufacturing method of the multilayer ceramic package of the present invention, in the first step, the electronic device (3) is mounted on the inner surface of the cap (2) by the method of mounting the electronic device (3) prepared in advance, or the electronic device ( The cap (2) including the electronic device (3) is manufactured by the method of forming 3) by lamination.

  In the second step, by performing a reflow process on the joined body of the multilayer ceramic substrate (1) and the cap (2), each connection metal pad (68) of the multilayer ceramic substrate (1) is once melted and the multilayer ceramic substrate. The sealing metal frame portion interposed between the opposing surfaces of (1) and cap (2) is once melted, and then, these molten metals are solidified, so that the laminated ceramic substrate (1) and cap (2) are integrated. It becomes. In this manner, the connection metal pad (68) is melted and solidified to form the internal electrode (5), and the electronic device (3) is connected to the external electrode (7) through the internal electrode (5). At the same time, the sealing metal frame is melted and solidified to form the sealing portion (4), and the space formed between the multilayer ceramic substrate (1) and the cap (2) is sealed from the periphery.

  In a specific configuration, in the first step, a frame-shaped sealing metal frame (8) surrounding the plurality of connection metal pads (68) is installed on the surface of the multilayer ceramic substrate (1), and the sealing is performed. The metal frame (8) is melted and solidified simultaneously with the connection metal pad (68) to form the sealing metal frame portion.

  According to the above specific configuration, the sealed metal frame (8) can be easily manufactured by punching using a mold or the like. Here, since the sealing metal frame (8) is formed in a flat plate shape as a whole, it can be stably placed on the surface of the multilayer ceramic substrate (1).

  In a specific configuration, the step of forming the plurality of connection metal pads (68) on the surface of the multilayer ceramic substrate (1) penetrates the multilayer ceramic substrate (1) from the front surface to the back surface to form a conductive path. A step of forming a plurality of conductor filling portions (6), and a plurality of round holes (91 corresponding to the exposed surface on the substrate surface side of the plurality of conductor filling portions (6) on the surface of the multilayer ceramic substrate (1). ) Having a flat plate-like jig (9) having a plurality of round holes (91) in the jig (9), and connecting metal balls (60) to each other. And a step of removing the jig (9) after melting.

  According to the above specific configuration, the connection metal ball (60) melts and rises on the surface of the conductor filling portion (6), and solidifies to form the connection metal pad (68). Here, since the connection metal ball (60) is held by the round hole (91) of the jig (9), the connection metal ball (60) is prevented from rolling and accurate positioning is realized.

  Alternatively, in another specific configuration, the step of forming the plurality of connection metal pads (68) on the surface of the multilayer ceramic substrate (1) includes the step of forming a conductive path that penetrates the multilayer ceramic substrate (1) from the front surface to the back surface. A plurality of cylindrical conductor filling portions (6) constituting a path on the back side of the substrate, and a plurality of cylindrical conductor inner peripheral walls (69) constituting a path from the conductor filling portion (6) to the substrate surface; And a step of accommodating the connection metal balls (60) in the openings of the plurality of conductive inner peripheral walls (69) of the multilayer ceramic substrate (1) and melting the connection metal balls (60), respectively. Have.

  According to the above specific configuration, the connecting metal ball (60) is melted and filled in the conductor inner peripheral wall (69) and rises to the surface of the conductor filling portion (6), which solidifies, A connecting metal pad (68) is formed. Here, since the connection metal ball (60) is held by the opening of the conductor inner peripheral wall (69), the connection metal ball (60) is prevented from rolling and accurate positioning is realized.

  According to the multilayer ceramic package and the manufacturing method thereof according to the present invention, in the second step, the connection metal pad (68) is melted and solidified to become the internal electrode (5), and the internal device (5) is used to form the electronic device (3). Is connected to the external electrode (7) and the sealing metal frame is melted and solidified to form the sealing portion (4). The sealing portion (4) allows the multilayer ceramic substrate (1) and the cap (2) to be connected. Since the space formed between the two is sealed, the number of steps is reduced as compared with the conventional manufacturing method in which the sealing step is performed after the wire bonding step.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
As shown in FIG. 1, the multilayer ceramic package according to the present invention has a multilayer ceramic substrate (1) having a cavity (10) recessed on the surface and a multilayer covering the cavity (10) of the multilayer ceramic substrate (1). The plate-shaped cap (2) joined to the surface of the ceramic substrate (1) and an electronic device (3) such as a surface acoustic wave element housed in the cavity (10) of the multilayer ceramic substrate (1). The

The cap (2) is composed of a ceramic substrate, and the electronic device (3) is installed on the inner surface thereof, that is, the surface facing the multilayer ceramic substrate (1).
A plurality of electrode pads (not shown) connected to the plurality of terminal portions of the electronic device (3) are formed on the inner surface of the cap (2).

  On the other hand, the multilayer ceramic substrate (1) is filled with a plurality of conductors formed by filling a through hole penetrating the multilayer ceramic substrate (1) with a conductive material such as Ag corresponding to the electrode pad of the cap (2). A portion (6) is formed, and an external electrode (7) made of Ag or the like is formed on the back surface of the multilayer ceramic substrate (1) in a region where each conductor filling portion (6) is exposed.

In addition, between the opposing surfaces of the multilayer ceramic substrate (1) and the cap (2), the plurality of electrode pads formed on the inner surface of the cap (2) and a plurality of conductor filling portions (of the multilayer ceramic substrate (1)) ( 6) and a plurality of internal electrodes (5) connecting each other, and surrounding these internal electrodes (5), a space formed between the multilayer ceramic substrate (1) and the cap (2) is formed. A metal sealing portion (4) for sealing is interposed.
Here, the internal electrode (5) is formed of the same metal as the sealing metal such as AuSn or AgSn forming the sealing portion (4).

  By surface mounting the multilayer ceramic package on a circuit board (not shown), the electronic device (3) can be mounted on the circuit board via the internal electrode (5), the conductor filling portion (6) and the external electrode (7). It will be connected to a specific electronic circuit.

2 to 12 show a manufacturing process of the multilayer ceramic package.
As shown in FIG. 8, in the first step, a cap (2) having an electronic device (3) integrally formed on the inner surface and a multilayer ceramic substrate (1) having a cavity (10) recessed on the surface are prepared. Make it. A plurality of electrode pads (not shown) electrically connected to a plurality of terminal portions (not shown) of the electronic device (3) are formed on the inner surface of the cap (2).

  Here, the cap (2) integrally provided with the electronic device (3) is produced on the inner surface of the cap (2) after the electronic device (3) and the cap (2) are produced by separate processes. However, it can also be produced by a method of forming the electronic device (3) on the inner surface of the cap (2) by a lamination process.

  On the other hand, as shown in FIG. 8, a plurality of bonding pads (67) made of Ag are formed on the multilayer ceramic substrate (1) at positions facing the plurality of electrode pads of the cap (2). A connection metal pad (68) made of AuSn is formed so as to cover (67). As shown in FIG. 6, a frame-like pad 66 made of Ag is formed on the surface of the multilayer ceramic substrate 1 so as to surround the cavity 10 and the plurality of connecting metal pads 68. . Further, as shown in FIG. 7, a plurality of external electrodes (7) made of Ag are formed on the back surface of the multilayer ceramic substrate (1). As shown in FIG. 8, the bonding pads (67) and the external electrodes (7) corresponding to each other are connected to each other by a conductor filling portion (6) made of Ag.

Further, in the first step, as shown in FIG. 6, a sealing metal frame (8) made of AuSn is produced in accordance with the contour shape of the multilayer ceramic substrate (1). The sealing metal frame (8) can be easily produced by punching a metal plate made of AuSn using a mold.
A sealing metal frame (8) is installed on the surface of the multilayer ceramic substrate (1) so as to surround the plurality of connection metal pads (68), and the sealing metal frame (8) is connected to the connection metal pad (68). Simultaneously melt and solidify.

In the second step, the multilayer ceramic substrate (1) and the cap (2) are joined as shown in FIG. As a result, as shown in FIG. 9, the electronic device (3) of the cap (2) is accommodated in the cavity (10) of the multilayer ceramic substrate (1).
Further, each electrode pad of the cap (2) and each connection metal pad (68) of the multilayer ceramic substrate (1) are joined together, and the outer periphery of the cap (2) and the sealing on the ceramic substrate (1) are sealed. The metal frame (8) is joined to each other.

In this state, a reflow process is performed on the joined body of the multilayer ceramic substrate (1) and the cap (2). Thereby, each connection metal pad (68) of the multilayer ceramic substrate (1) and the sealing metal frame (8) on the multilayer ceramic substrate (1) are once melted, and then these molten metals are solidified. The multilayer ceramic substrate (1) and the cap (2) are integrated.
In this way, the connection metal pad (68) is melted and solidified to form the internal electrode (5), and the electronic device (3) is connected to the external electrode (7) through the internal electrode (5). At the same time, the sealing metal frame (8) is melted and solidified to form the sealing portion (4), and the space formed between the multilayer ceramic substrate (1) and the cap (2) is sealed from the periphery. Is done.
As a result, the multilayer ceramic package of the present invention shown in FIG. 1 is completed.

2 to 5 show the manufacturing process of the multilayer ceramic substrate (1) shown in FIG.
First, as shown in FIG. 2 (a), after a plurality of through holes (12) are opened in the first green sheet (11), an Ag conductive paste is formed in each through hole (12) as shown in FIG. 2 (b). Fill (61). After that, as shown in FIG. 2C, an Ag conductive paste (62) is printed on the back surface of the green sheet (11) in an electrode shape so as to overlap the exposed portion of the conductive paste (61).

  In addition, after opening one central opening (14) and a plurality of through holes (15) in the second green sheet (13) as shown in FIG. 3 (a), each through hole as shown in FIG. 3 (b). Fill hole (15) with conductive paste (63) made of Ag. Thereafter, as shown in FIG. 3 (c), the conductive paste (65) is printed in a pad shape on the surface of the green sheet (13) so as to overlap the exposed portion of the conductive paste (63). The conductive paste (64) is printed in a frame shape.

  Next, as shown in FIG. 4, the first green sheet (11) and the second green sheet (13) are joined, and both the green sheets (11) and (13) are pressed from both sides. Thereby, the integral laminated body shown in FIG. 5 is obtained. And this laminated body is baked and Au plating is further applied to the exposed metal surface. As a result, the multilayer ceramic substrate (1) shown in FIG. 8 is obtained. Here, the pad-like conductive paste (65) becomes the bonding pad (67), the frame-like conductive paste (64) becomes the frame-like pad (66), and the electrode-like conductive paste (62) becomes the external electrode (7). It becomes. Note that the Au plating layer is not shown.

10 and 11 show a process in the case of forming the connection metal pad (68) without providing the bonding pad (67) on the surface of the multilayer ceramic substrate (1).
First, as shown in FIGS. 10 and 11A, a jig (9) made of a ceramic plate having a plurality of round holes (91) at a position corresponding to the exposed surface of each conductor filling portion (6) is prepared. The jig (9) is superposed on the surface of the multilayer ceramic substrate (1).
Next, as shown in FIG. 11 (b), AuSn connection metal balls (60) are accommodated in the respective round holes (91) of the jig (9), and after melting the connection metal balls (60), the jig Remove (9). As a result, as shown in FIG. 11 (c), the connecting metal pad (68) that rises on the exposed surface of each conductor filling portion (6) is formed.
An Au plating layer is formed on the exposed surface of each conductor filling portion (6), but is not shown.

  According to the above process, since the connecting metal ball (60) is held in the round hole (91) of the jig (9), the connecting metal ball (60) is prevented from rolling and accurate positioning is realized. Is done.

FIG. 12 shows another process when the connection metal pad (68) is formed on the surface of the multilayer ceramic substrate (1) without providing the bonding pad (67).
First, as shown in FIG. 12 (a), the multilayer ceramic substrate (1) has a conductor-filled portion in which through holes are filled with Ag up to a height lowered by a predetermined distance from the surface of the multilayer ceramic substrate (1). (6) is formed, and an Ag inner peripheral wall (69) made of Ag that rises from the upper surface of the conductor filling portion (6) to the surface of the multilayer ceramic substrate (1) is formed.
Next, as shown in FIG. 12 (b), AuSn connection metal balls (60) are accommodated in the openings of the inner peripheral walls (69) of the respective conductors of the multilayer ceramic substrate (1), and the connection metal balls (60) are attached. Melt. As a result, as shown in FIG. 12C, a connection metal pad (68) that rises on the exposed surface of each conductor filling portion (6) is formed.
An Au plating layer is formed on the exposed surface of each conductor filling portion (6) and the surface of the conductor inner peripheral wall (69), which is not shown.

  According to the above process, since the connection metal ball (60) is held by the opening of the conductor inner peripheral wall (69), the connection metal ball (60) is prevented from rolling and accurate positioning is realized. .

As described above, according to the method for manufacturing a multilayer ceramic package according to the present invention, in the second step, the connection metal pad (68) is melted and solidified to become the internal electrode (5). At the same time that (3) is connected to the external electrode (7), the sealing metal frame (8) is melted and solidified to form the sealing portion (4), and the laminated ceramic substrate (1) is formed by the sealing portion (4). Since the space formed between the cap and the cap (2) is sealed, the number of man-hours is reduced as compared with the conventional manufacturing method in which the sealing step is performed after the wire bonding step.
The sealing metal frame (8) may be disposed on the surface of the multilayer ceramic substrate (1) when the connecting metal ball (60) is melted and solidified, and melted and solidified simultaneously with the connecting metal ball (60). .

1 is a cross-sectional view of a multilayer ceramic package according to the present invention. It is a figure which shows the manufacturing process of the 1st green sheet used for preparation of a multilayer ceramic substrate. It is a figure which shows the manufacturing process of the 2nd green sheet used for preparation of a multilayer ceramic substrate. It is a figure which shows the joining process of the 1st green sheet and the 2nd green sheet. It is sectional drawing which shows the laminated body of a 1st green sheet and a 2nd green sheet. It is a perspective view of a multilayer ceramic substrate and a sealing metal frame. It is a perspective view showing the back surface of a multilayer ceramic substrate. It is sectional drawing which shows the joining process of a laminated ceramic substrate and a cap. It is sectional drawing of the laminated body of a laminated ceramic substrate and a cap. It is a top view of a jig | tool. It is a series of sectional views showing a process of forming a sealing metal pad on a multilayer ceramic substrate. It is a series of sectional views showing another process of forming a sealing metal pad on a multilayer ceramic substrate. It is a series of sectional views showing a manufacturing process of a conventional multilayer ceramic package.

Explanation of symbols

(1) Multilayer ceramic substrate
(2) Cap
(3) Electronic devices
(4) Sealing part
(5) Internal electrode
(6) Conductor filling part
(7) External electrode
(10) Cavity

Claims (6)

  A multilayer ceramic substrate (1) having a cavity (10) recessed on the surface, and a cap (2) covering the cavity (10) of the multilayer ceramic substrate (1) and bonded to the surface of the multilayer ceramic substrate (1) And an electronic device (3) accommodated in the cavity (10) of the multilayer ceramic substrate (1), and the back surface of the multilayer ceramic substrate (1) is connected to the electronic device (3) via a conductive path. In the multilayer ceramic package in which a plurality of external electrodes (7) are formed, the electronic device (3) is disposed on the inner surface of the cap (2), and the opposing surface of the multilayer ceramic substrate (1) and the cap (2). A plurality of internal electrodes (5) for connecting the electronic device (3) to the conductive path in the multilayer ceramic substrate (1) are interposed therebetween, and surround these internal electrodes (5). Form between multilayer ceramic substrate (1) and cap (2) Layered ceramic package metallic sealing section for sealing the spaces (4), characterized in that the interposed.   2. The multilayer ceramic package according to claim 1, wherein the plurality of internal electrodes are made of the same metal as a sealing metal forming the sealing portion. A multilayer ceramic substrate (1) having a cavity (10) recessed on the surface, and a cap (2) covering the cavity (10) of the multilayer ceramic substrate (1) and bonded to the surface of the multilayer ceramic substrate (1) And an electronic device (3) accommodated in the cavity (10) of the multilayer ceramic substrate (1), and the back surface of the multilayer ceramic substrate (1) is connected to the electronic device (3) via a conductive path. In the method of manufacturing a multilayer ceramic package in which a plurality of external electrodes (7) are formed,
A multilayer ceramic substrate (1) having a cap (2) having an electronic device (3) on the inner surface, a cavity (10) recessed in the front surface, and a plurality of external electrodes (7) formed on the rear surface A first step of producing
By joining and integrating the multilayer ceramic substrate (1) and the cap (2), the electronic device (3) of the cap (2) is electrically connected to the plurality of external electrodes (7) of the multilayer ceramic substrate (1). A second step, and in the first step, the surface of the multilayer ceramic substrate (1) is made to correspond to the plurality of electrode pads formed on the inner surface of the cap (2), and the plurality of external electrodes ( 7) A plurality of connection metal pads (68) connected to the conductive path via the conductive path are formed. In the second step, each connection metal pad (68) of the multilayer ceramic substrate (1) and each electrode pad of the cap (2) are formed. And the sealing metal frame portion surrounding the plurality of connection metal pads (68) between the opposing surfaces of the multilayer ceramic substrate (1) and the cap (2), and the connection. The metal pad (68) and the sealing metal frame are melted once and then solidified. Method of manufacturing a multilayer ceramic package, characterized in that.   In the first step, a frame-shaped sealing metal frame (8) surrounding the plurality of connection metal pads (68) is installed on the surface of the multilayer ceramic substrate (1), and the sealing metal frame (8) The method of manufacturing a multilayer ceramic package according to claim 3, wherein the sealing metal frame portion is formed by melting and solidifying at the same time as the connection metal pad (68).   The step of forming the plurality of connection metal pads (68) on the surface of the multilayer ceramic substrate (1) includes a plurality of conductor filling portions (6 And a flat plate-like jig having a plurality of round holes (91) corresponding to the exposed surface of the plurality of conductor filling portions (6) on the surface of the multilayer ceramic substrate (1). The fixture (9) is installed, and the connecting metal balls (60) are respectively accommodated in the plurality of round holes (91) of the jig (9), and the connecting metal balls (60) are melted. The method for producing a multilayer ceramic package according to claim 3 or 4, wherein (9) is removed.   The step of forming the plurality of connection metal pads (68) on the surface of the multilayer ceramic substrate (1) constitutes a path on the back side of the substrate among conductive paths penetrating the multilayer ceramic substrate (1) from the surface to the back surface. Forming a plurality of cylindrical conductor filling portions (6), and a plurality of cylindrical conductor inner peripheral walls (69) constituting paths from the conductor filling portions (6) to the substrate surface; The laminated ceramic according to claim 3 or 4, wherein the connection metal balls (60) are respectively accommodated in the openings of the plurality of conductive inner peripheral walls (69) of the substrate (1), and the connection metal balls (60) are melted. Package manufacturing method.

Images