JP3876259B2 - Manufacturing method of ceramic substrate - Google Patents

Description

  The present invention relates to a method for manufacturing a ceramic substrate.

  Conventionally, a ceramic substrate has been known which has a cavity for mounting electronic components such as SAW filters, transistors, LSIs, crystal resonators, and light emitting diodes and electrically connects these electronic components to other substrates. It has been. An example of such a ceramic substrate is shown in FIG. The ceramic substrate 100 of FIG. 11 has a quadrilateral plate shape in which a substrate body made of ceramic has a first main surface CP1, a second main surface CP2, and a side surface SF, and a cavity 101 is formed on the first main surface CP1. An electronic component (not shown) is mounted on the bottom surface 102 of. The side surface SF is provided with a semi-cylindrical recess 104, and the metallized layer 103 formed on the inner peripheral surface thereof is electrically connected to the electronic component mounted on the cavity bottom surface CP2 via an internal conductor layer (not shown). Connected to.

  For manufacturing the ceramic substrate 100, for example, a green sheet lamination method is used. For this, first, several ceramic green sheets forming the substrate body are prepared, and through holes to be formed into the cavities 101 and the recesses 104 are formed at predetermined locations using a punched metal fitting or the like. Thereafter, a metallized paste containing a metal such as Mo or W is printed on the surface of the green sheet or the recess 104, and the green sheets are stacked and pressure bonded. Then, the green sheet is fired at a high temperature together with the metallized paste to obtain a sintered body in which the laminated green sheets are integrated, and the metallized layer 103 and the internal conductive layer are formed.

In these steps, a large number of ceramic green sheets are used so that a large number of ceramic substrates 100 can be obtained at a time. An example thereof is shown in FIG. 12 (a) surface view and (b) sectional view. In FIG. 12, a collective substrate 106 in which a plurality of ceramic substrates 100 are integrated in the in-plane direction is formed. By placing break grooves b1 and b2 along the planned separation line l before firing and separating individual substrate units after firing (so-called chocolate break), a large number of ceramic substrates 100 can be manufactured at one time. In the step of forming the break groove as shown in FIG. 12B, the break blades 105 are inserted from the first main surface CP1 side and the second main surface CP2 side, which is sufficient to separate the individual ceramic substrates 100. Depth. The following Patent Document 1 and Patent Document 2 disclose the formation of such a break groove and its application.
JP 2000-63414 A JP 2000-252379 A

  On the other hand, a ceramic substrate having a form as shown in FIG. 1 may be desired. In FIG. 1A, an open cavity 2 that is open on the side is formed in the ceramic substrate 1 because the wall is not formed on one side. Then, a mounting portion of electronic parts, wiring, and connection terminals (not shown) are formed on the bottom surface 4 of the open cavity. As shown in FIG. 1B, there is a ceramic substrate in which a concave portion 22 is provided on a side surface and a metallized layer 5 is formed on an inner peripheral surface thereof to be a connection terminal with another substrate.

  However, if the ceramic substrate 1 having the above shape is manufactured using a large size as shown in FIG. 12, a break groove having a sufficient depth cannot be formed because it is difficult for the break blade to reach the bottom of the open cavity 2 (see FIG. 12). 13), as a result, there is a problem that burrs are generated when the ceramic substrates 1 are separated from each other.

  The present invention is made in the background as described above, and in particular, a method of manufacturing a ceramic substrate having an open cavity whose side is opened by the wall being not formed on one side, It is an object of the present invention to provide a method for manufacturing a ceramic substrate that can be manufactured in large numbers at a time and hardly generate burrs.

Means for Solving the Problems and Effects of the Invention

  In order to solve the above-described problems, a method for manufacturing a ceramic substrate according to the present invention includes a quadrilateral plate-like substrate body and a cavity bottom surface on a first main surface of the substrate body to form a cavity having the substrate body as a bottom. A plurality of substrate units having a wall portion protruding from the first main surface so as to surround the region to be formed are integrated in the in-plane direction so as to be partitioned by a predetermined separation line for separating the substrate units. Manufacturing the assembled substrate, and cutting the aggregate substrate along the planned separation line to separate each substrate unit, and the substrate unit has a wall portion not formed on one side of the substrate body. Thus, the cavity is formed as an open cavity opened laterally at the side, and in the collective substrate, the open cavities of two substrate units adjacent to each other with the planned separation line sandwich the open side. Min By aligning with the planned line side, it is integrated with the wall part to form a connection cavity, and at the connection position, on the first main surface of the pair of wall parts facing each other across the connection cavity, along the planned separation line A first break groove is formed, a second break groove is formed at a position corresponding to the first break groove on the second main surface side of the substrate body, and a pair of cavities are formed in a region where the connection cavity of the substrate body is formed. Break through-holes along the planned separation line are formed at positions where the first break grooves formed on the walls of the substrate are connected, and the first break groove, the second break groove, and the break through-hole form a substrate. The main feature is that the units are separated from each other.

  In the present invention, a collective substrate of ceramic substrates having an open cavity is manufactured, and the collective substrate is formed so that two substrate units have the open side coincident with the planned separation line. In this collective substrate, the walls of the open cavities are integrated to form a connection cavity. And in a connection position, a break groove | channel is formed from both main surfaces in two wall parts which oppose on both sides of a connection cavity. Break through holes are formed along the planned separation line on the bottom surface of the connection cavity, and the ceramic substrates are separated from each other by the break grooves and the break through holes. In this way, the break blade can be inserted from the first main surface and the second main surface to a desired depth in the wall portion of the open cavity, and a break through hole is formed in the cavity bottom portion where it is difficult to insert the break blade. Therefore, no burrs are generated when the ceramic substrate is separated.

  A substrate unit having a plurality of the above-described open cavities can also be manufactured. For example, open cavities can be separately formed on two opposing sides of a quadrilateral plate-like substrate body. In this case, the collective substrate shares the open cavity with the adjacent ceramic substrates.

  Further, according to the present invention, an electronic component mounting cavity different from the above open cavity is formed so as to form a cavity bottom surface on the first main surface of the substrate body, and the electronic component mounting cavity is formed on the cavity bottom surface of the electronic component mounting cavity. A mounting part can also be formed.

  In the present invention, the open cavities are respectively formed on two opposing sides of the quadrilateral plate-like substrate body, a light emitting element mounting cavity different from the two open cavities is further formed, and the light emission A light emitting element mounting portion is formed on the cavity bottom surface of the element mounting cavity, a fillet portion is formed along a path surrounding the light emitting element, and a light beam emitted from the light emitting element is transmitted to the surface of the fillet portion by a predetermined amount. Reflect in the direction.

  In the present invention, a metal layer is formed on the inner peripheral surface of the light emitting element mounting cavity and the outer peripheral edge of the bottom surface of the cavity, and the fillet portion is formed so as to straddle these two metal layers. This fillet portion can be formed using, for example, an Ag-based brazing material.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
2A is a front view, FIG. 2B is a cross-sectional view, and FIG. 3 is a perspective view. As shown in these drawings, an aggregate substrate 6 in which a plurality of substrate units of ceramic substrates are integrated is first formed and cut along the predetermined separation lines l and l ′ to obtain individual substrate units. The substrate unit is a quadrilateral shape, and a wall portion W is provided so as to surround the cavity bottom surface 4. In the collective substrate of the present invention, two substrate units are connected so that the open side of the open cavity 2 coincides with the planned separation line, and the open cavity 2 is integrated with the wall portion W to form a connecting cavity 9. ing. In order to form a break groove in the collective substrate 6, as shown in FIG. 2B, the break blade 8 is inserted from the first main surface CP1 along the planned separation lines l and l ′ to form the first break groove b1. At the same time, the break blade 8 is inserted from the second main surface CP2 to form the second break groove b2. Further, a break through hole 7 is formed in the formation region of the connection cavity 9 along the planned separation line l ′. In this way, since two substrate units can be easily separated in the break through hole 7, burrs are hardly generated in the dividing step.

  When the height of the wall W is h1 and the thickness of the cavity bottom is h2, the first break groove depth d1 is 50-60% of h1, and the second break groove depth d2 is 50-60 of h2. % Is desirable. If it is less than 50%, it becomes difficult to break, and if it exceeds 60%, the break blade may damage the internal conductive layer (not shown).

  After the assembly substrate 6 is manufactured as described above, the ceramic green sheets are sintered and the individual substrate units are separated along the planned separation lines l and l ′, so that many ceramic substrates 1 shown in FIG. 4 can be manufactured. . The ceramic substrate 1 of FIG. 4 has an open cavity 2. The open cavity 2 is formed by dividing the connecting cavity 9 in the collective substrate 6.

  As described above, in the present invention, the break through hole 7 is formed in the collective substrate 6 along the planned separation line l ', so that burrs are hardly generated in the process of separating individual substrate units. Here, as shown in FIG. 13, if the break through hole 7 is not formed, the break blade 8 from the first main surface CP1 does not reach the bottom 4 of the connection cavity, so that the depth is not necessarily sufficient. Break groove b2 'cannot be formed. As a result, burrs may occur in the break groove b2 'in the process of dividing the substrate unit. Further, if the depth d3 of the break groove b2 ′ is made sufficiently deep, the pressure of the break blade 8 inserted from the second main surface CP2 side increases, and as a result, the depth of the break groove b2 in the wall W is necessary. The problem which becomes deeper than that arises.

  On the other hand, as shown in FIG. 5A, it is possible to form an electronic component mounting cavity 10 in addition to the open cavity 2. A mounting part (not shown) for electronic parts such as SAW filters, transistors, LSIs, crystal resonators, and light emitting diodes is formed in the electronic part mounting cavity 10, and a conductive layer connected to the mounting part is connected to the open cavity 2. It is pulled out to form a connection portion with another substrate. Further, as shown in FIG. 5B, a recess 22 is formed on the side surface, a metallized layer 5 electrically connected to the internal conductive layer is formed on the inner peripheral surface thereof, and this metallized layer 5 is attached to another substrate. It is good also as a connection part.

  Further, as shown in the perspective view of FIG. 6A, the open cavities 2 are formed on the two opposing sides of the quadrilateral ceramic substrate 1, and different from these open cavities 2. It is also possible to form the electronic component mounting cavity 10. In the embodiment of FIG. 6, a light emitting element 13 such as a light emitting diode is mounted in the electronic component mounting cavity 10. Specifically, the mounting portion 14 is formed on the bottom surface 19 of the electronic component mounting cavity 10, and the light emitting element 13 is mounted thereon. In FIG. 6, three types of light emitting elements of red, blue, and green are mounted to extract white light. On the other hand, metal layers 12a and 12b are formed on the inner peripheral surface 20 and the bottom surface 19 of the cavity, respectively, and an Ag-based filler material 15 is formed so as to straddle the two metal layers 12a and 12b. The surface of the fillet portion 15 is a light reflecting surface 16 for reflecting the emitted light beam from the light emitting element 13 to the outside. As will be described later, the fillet portion 15 is formed by placing Ag-based brazing particles on the metal layer 12b, performing high temperature treatment, and reflowing. Since the surface of the fillet portion 15 is smoothed by the reflow, the light reflecting surface 16 has a high light reflectance. Further, both the metal layers 12a and 12b can be formed by printing and applying metallized paste, and the processing accuracy is high. Therefore, the processing accuracy of the fillet portion 15 formed over the two metal layers 12a and 12b is also high. Thus, it is possible to suppress variations such as the light reflection angle.

  The substrate body of FIG. 6 is formed by laminating three ceramic layers 11a, 11b, and 11c. A metal layer 12a is formed on the surface of the ceramic layer 11a, and a pad 17 and a metal layer 12a are formed on the ceramic layer 11b. The pad 17 and the light emitting element 13 are electrically connected by a wire 18. Further, the pad 17 is electrically connected to the metal layer 12b through a conductive layer 21 penetrating the ceramic substrate 11b. A part of the metal layer 12b is exposed from the open cavity 2, and this exposed part is used as a connection part CN with another substrate.

  Next, a method for manufacturing the ceramic substrate 1 shown in FIG. 6 will be described with reference to the process diagrams of FIGS. First, ceramic green sheets 11a 'to 11c' are prepared (step 1). Thereafter, as shown in Step 2, the connecting cavity 9, the light emitting element mounting cavity 10, the break through hole 7, and the through hole to be the conductive layer 21 are punched and formed at predetermined positions. Next, the metallized pastes 14 ′, 12 a ′, 12 b ′, 17 ′, and 21 ′ are printed and applied to predetermined positions (Step 3). For printing the metallized paste, for example, a screen printing method is employed. Thereafter, the ceramic green sheets 11a 'to 11c' are laminated and pressure-bonded, and fired at a high temperature together with the metallized paste to obtain an aggregate substrate 6 in which the ceramic green sheets are integrated (step 4). As a result of baking, the metallized pastes 14 ′, 12 a ′, 12 b ′, 17 ′, and 21 ′ become the mounting portion 14, the metal layers 12 a and 12 b, the conductive layer 21, and the pad 17. After this, a fillet portion is formed so as to straddle the metal layer 12 a formed on the inner peripheral surface 20 of the light emitting element mounting cavity 10 and the metal layer 12 b formed on the outer peripheral edge portion of the bottom surface 19. . For this purpose, first, as shown in step 5, Ag-based brazing filler metal particles 15 'are placed on the metal layer 12b. Then, the particles 15 ′ are heated together with the aggregate substrate 6 at a high temperature to reflow the Ag brazing material, thereby forming the fillet portion 15. The surface of the fillet portion 15 formed in this way is smooth and has a high light reflectance, and is suitably used as a light reflecting surface.

  Next, in order to separate the collective substrate 6 manufactured as described above into individual substrate units, break grooves b1 and b2 shown in FIG. 10 are formed. First, the first break groove b1 is formed from the first main surface CP1 along the planned separation line l 'in the pair of wall portions W sandwiching the connecting cavity 9 (the vertical break groove b1 in FIG. 10). The first break groove b1 is also formed in the lateral direction. Further, the second break groove b2 is inserted from the second main surface CP2 at a position corresponding to the first break groove b1. On the other hand, a break through hole 7 is formed in advance at a position where the first break groove b <b> 1 formed in the wall portion W is connected to the connection cavity forming region. Each of the substrate units can be separated by using the first break groove b1, the second break groove b2, and the break through hole 7.

  As described above, in the present invention, since the break through hole 7 is formed by punching, in the step of separating each substrate unit after firing, it can be separated without causing burrs on the bottom surface of the cavity.

Example of ceramic substrate The (a) surface view and (b) sectional drawing which show one Embodiment of the manufacturing method of a ceramic substrate. Similarly perspective view. An embodiment which shows a substrate unit of a ceramic substrate concerning the present invention. Embodiment different from FIG. One embodiment of the ceramic substrate carrying a light emitting element. An example of the method of manufacturing the ceramic substrate of FIG. The figure following FIG. The figure following FIG. The figure following FIG. Conventional ceramic substrate. (A) Surface view and (b) Cross-sectional view of a conventional aggregate substrate. (A) surface view and (b) cross-sectional view when a break groove is not formed at the bottom of the cavity.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ceramic substrate 2 Open cavity 3 Open side part 4 Cavity bottom face 6 Collective board 7 Break through-hole 8 Break blade 9 Connection cavity 10 Electronic component mounting cavity 13 Light emitting element 15 Fillet part 16 Light reflecting surface 22 Recessed part CP1 First main surface W Wall 1 l Planned separation line l ′ Planned separation line b1 in which the open sides of the two substrate units coincide with each other First break groove

Claims (4)

In order to form a quadrilateral plate-like substrate main body and a cavity having the substrate main body as a bottom, the substrate main body protrudes from the first main surface so as to surround a region serving as a cavity bottom surface on the first main surface. Manufacturing a collective substrate in which a plurality of substrate units having a wall portion are integrated in an in-plane direction in a form partitioned by a planned separation line for separating the substrate unit, and the aggregate substrate is used as the planned separation line A step of separating the substrate into individual substrate units by cutting along
In the substrate unit, the wall portion is not formed on one side portion of the substrate body, whereby the cavity is an open cavity opened laterally at the side portion. The open cavities of the two substrate units adjacent to each other with the planned separation line are integrated with the wall portion so that the open side coincides with the planned separation line side, thereby forming a coupling cavity, and its coupling position. In the first main surface of the pair of wall portions opposed to each other with the connection cavity interposed therebetween, a first break groove is formed along the planned separation line, and the second main surface side of the substrate body is the first main surface. A second break groove is formed at a position corresponding to the one break groove, and the first cavity formed in the pair of wall portions is formed in the connection cavity forming region of the substrate body. A break through hole is formed along the predetermined separation line at a position connecting the break grooves, and the substrate units are separated from each other by the first break groove, the second break groove, and the break through hole. A method for manufacturing a ceramic substrate. The method for manufacturing a ceramic substrate according to claim 1, wherein a mounting portion for an electronic component is formed on a bottom surface of the open cavity. An electronic component mounting cavity different from the open cavity is formed so as to form a cavity bottom surface on the first main surface of the substrate body, and an electronic component mounting portion is formed on the cavity bottom surface of the electronic component mounting cavity. The method for producing a ceramic substrate according to claim 1 or 2, wherein the ceramic substrate is formed. The open cavities are respectively formed on two opposing sides of the quadrilateral plate-like substrate body, and a light emitting element mounting cavity different from the two open cavities is further formed, and the light emitting element mounting cavity A mounting part of the light emitting element is formed on the bottom surface of the cavity, a fillet part is formed along a path surrounding the light emitting element, and the emitted light beam from the light emitting element is reflected in a predetermined direction on the surface of the fillet part. The method for manufacturing a ceramic substrate according to any one of claims 1 to 3.

Images