JP2007027592A - Ceramic package and manufacturing method therefor, ceramic package for taking many pieces, and its manufacture - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ceramic package excellent in a sealing nature of a cavity. <P>SOLUTION: A nearly rectangular cavity 22 in plane view is formed in a ceramic package 10. On a sidewall 48 at the corner of the cavity 22, there is formed a castellation 41 structured such that a conductor 43 is formed on a surface of a concave groove 42. The concave groove 42 takes on a shape of a cross section along an arc 53. Out of four sides 51 defining outer lines of the cavity 22 at the plan view, extended lines of two adjacent sides 51 cross each other, the point of which is assumed to be a virtual intersection P1. A virtual center point P2 that is offset from the virtual intersection P1 in a center direction of the cavity 22 is assumed, and around its point a virtual circle 52 is assumed. The region of the virtual circle 52 outside the outer lines of the cavity 22 at its plan view is the arc 53. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a ceramic package in which castellations are formed on a side wall of a cavity and a manufacturing method thereof, a multi-cavity ceramic package, and a manufacturing method thereof.

  Conventionally, various small ceramic packages for accommodating elements such as semiconductor elements and crystal oscillators have been proposed. This type of ceramic package has a cavity, and the element is mounted on the bottom surface of the cavity. Conventionally, for example, a metallized layer is provided on the upper surface of the cavity outer periphery of the ceramic package, and a plating layer and a brazing material layer are provided on the metallized layer. On the brazing material layer, a metal cap is further attached via a metal ring. That is, the outer peripheral portion of the cavity functions as a seal portion for blocking communication between the inside and outside of the cavity. Also, via conductors (hole-filled vias) that penetrate the package in the vertical direction are provided in the cavity outer peripheral portion in order to conduct the metallization layer on the upper surface of the cavity and the conductor layer on the lower surface of the package.

However, in recent years, the wall thickness of the outer peripheral portion of the cavity has been reduced with the miniaturization of the package, so it is difficult to secure a space where the via conductor can be formed in a complete shape. Therefore, a conductive structure called “castellation” in which the via conductor is divided along the axial direction is adopted and formed on the side wall of the cavity (see, for example, Patent Document 1). In Patent Document 1, a castellation having a semi-oval cross section is installed at a location corresponding to a side of a substantially rectangular cavity in plan view. For example, a castellation having such a structure can be formed by cutting a part of a via conductor when a cavity is formed by machining a ceramic material on which a via conductor is formed.
JP 2004-55985 A

However, in the case of the ceramic package described in Patent Document 1, if the wall thickness of the cavity outer peripheral portion is further reduced, even if the castellation has a smaller cross-sectional area than the via conductor, there is a sufficient length of the seal path. It becomes difficult to secure. Therefore, the leak occurrence rate is increased. Moreover, since such a ceramic package is usually manufactured by a multi-cavity technique, a break process for dividing a large package into individual pieces is essential. However, if stress is applied during the break process, cracks are likely to occur around the castellation at the outer periphery of the package, causing a leak.
Further, if machining is performed at the time of forming the cavity and the castellation, burrs are likely to occur at the edge of the concave groove portion in the castellation, and the yield is deteriorated. In this case, if work for removing burrs is performed, high manufacturing costs are unavoidable.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a ceramic package and a multi-cavity ceramic package excellent in cavity sealing performance. Another object of the present invention is to provide a method suitable for manufacturing the above package.

  As means (means 1) for solving the above-mentioned problem, there is a castellation having a structure in which a substantially rectangular cavity in plan view capable of mounting an element is formed on a ceramic substrate, and a conductor part is provided on the surface of the groove part. In the ceramic package formed on the side wall of the cavity, the concave groove portion is disposed on the side wall of the corner portion of the cavity, and two adjacent sides out of four sides that define the outer shape of the cavity in plan view. When a virtual circle centered on a virtual center point that is offset from the virtual intersection point in the direction of the center of the cavity is assumed to be a point where the extended lines of two sides intersect, and in the plan view of the cavity in the virtual circle There is a ceramic package characterized by exhibiting a cross-sectional shape along an arc that is a region outside the outer shape line.

  Therefore, according to the package of the means 1, the castellation having the above-mentioned cross-sectional shape is arranged on the side wall of the corner portion of the cavity in addition to being offset in the cavity center direction, unlike the one described in Patent Document 1. ing. For this reason, a sufficient seal path can be secured in the castellation forming portion, and the leak occurrence rate can be kept low.

  Preferable examples of the ceramic substrate constituting the package of means 1 include a ceramic multilayer substrate mainly composed of alumina, beryllia, aluminum nitride, boron nitride, silicon nitride, low-temperature fired ceramic, and the like. The ceramic substrate is a substantially plate-like member having a main surface and a back surface, and a cavity is formed on the main surface side.

  The cavity has a substantially rectangular shape in plan view, and one or more elements can be mounted on the bottom surface of the cavity. An element mounting metallized layer may be formed on the element mounting portion. Examples of the element include a semiconductor element and a crystal oscillator. The package of the means 1 may further include a conductor layer other than the metallized layer for mounting the element. Examples of such a conductor layer include an inner layer conductor pattern made of a metallized layer provided inside the package, and a pad made of a metallized layer provided on the surface opposite to the main surface of the package.

  On the side wall of the corner portion of the cavity, a castellation having a structure in which a conductor portion is provided on the surface of the groove portion is formed. The concave groove portion is disposed on the side wall of the corner portion of the cavity, and a virtual intersection is defined as a point where the extension lines of two adjacent sides of the four sides that define the outer shape of the cavity in plan view intersect. When a virtual circle centered on a virtual center point that is offset in the center direction of the cavity from the virtual intersection is hypothesized, the virtual circle becomes an arc that is an area outside the outline in plan view of the cavity. It has a cross-sectional shape along.

  In this case, the offset amount of the virtual center point with respect to the virtual intersection is preferably 0.75 times or more and 1.25 times or less the radius of the virtual circle, in particular 0.80 times or more and 1. More preferably, it is 20 times or less. If it is less than 0.75 times, a sufficient seal path cannot be secured in the corner portion, and it is difficult to reduce the incidence of burrs at the edge of the castellation. On the contrary, if it exceeds 1.25 times, it becomes difficult to form a large conductor portion, and it becomes difficult to achieve low resistance.

  By the way, if the offset amount is set to zero and castellations are formed on the sidewalls of the corners of the cavity, the arc length corresponding to the concave grooves in the castellations is 270 / of the circumference of the virtual circle. It becomes about 360. On the other hand, in the offset castellation of the means 1, the length of the arc corresponding to the concave groove is smaller than 270/360 of the circumference of the imaginary circle, and its preferred range is 150/360 or more and 240 / 360 or less, and a particularly preferable range is 170/360 or more and 220/360 or less. If it is less than 150/360, the offset amount becomes too large. As a result, it becomes difficult to form a large conductor portion, and it becomes difficult to achieve a low resistance. On the contrary, if it exceeds 240/360, the offset amount becomes too small, so that a sufficient seal path cannot be secured in the corner portion. Moreover, it becomes difficult to reduce the incidence of burrs at the edge of the castellation.

  Similarly to the above, assuming that the offset amount is set to zero and a castellation is formed on the side wall of the corner portion of the cavity, in the castellation, the concave groove portion having an arcuate cross section and the cavity in a plan view The angle formed by the outline is about 90 °. In the castellation described in Patent Document 1, this angle is about 90 °. In this case, the occurrence rate of burrs at the edge of the castellation increases, leading to a decrease in yield. On the other hand, in the offset castellation of the means 1, the angle formed by the concave groove portion having an arcuate cross section and the outline of the cavity in plan view is larger than 90 °, and its preferred range is 100 °. It is 140 degrees or less. If this angle is within the above range, the occurrence rate of burrs at the edge of the castellation can be kept low, and the yield is improved. The angle is more preferably 105 ° or more and 135 ° or less.

  As another means (means 2) for solving the above-described problem, a caster having a structure in which a cavity having a substantially rectangular shape in plan view capable of mounting an element is formed on a ceramic substrate and a conductor portion is provided on the surface of the groove portion. In the ceramic package in which the groove is formed on the side wall of the cavity, the concave groove portion is disposed on the side wall of the corner portion of the cavity, and the cross-sectional shape thereof has an arc shape, and the concave groove portion has an arc shape of the cross section. There is a ceramic package characterized in that an angle formed by the outline of the cavity in plan view is 100 ° or more and 140 ° or less.

  Therefore, according to the package of the means 2, the castellation having the above cross-sectional shape is arranged on the side wall of the corner portion of the cavity, unlike the one described in Patent Document 1. For this reason, a sufficient seal path can be secured in the castellation forming portion, and the leak occurrence rate can be kept low. In addition, since the angle formed by the concave groove portion and the outline of the cavity in plan view is within a preferable range, the occurrence rate of burrs at the edge of the castellation can be kept low, and the yield is improved.

  As a suitable method (means 3) for manufacturing the ceramic package of the means 1 and 2, a preparatory step for preparing a ceramic unsintered body to be a ceramic substrate, and a cavity formation schedule in the ceramic unsintered body A hole forming step for forming a hole in a corner portion of the portion, a conductor portion forming step for forming a conductor portion in the hole portion, and removing the cavity formation scheduled portion in the ceramic unsintered body by machining, A cavity having a substantially rectangular shape in plan view is formed, and a castellation having a structure in which the conductor portion is provided on the surface of the groove portion is formed by cutting out the hole and a part of the conductor portion at that time. Simultaneously forming the cavity and castellation and firing the ceramic green body on which the cavity and castellation are formed. There are provided methods for producing the ceramic package including a firing step to mix the substrate.

  Therefore, according to this manufacturing method, the cavity and the castellation can be formed simultaneously by removing the cavity formation scheduled portion by machining, so that an increase in man-hours can be prevented. Moreover, since this simultaneous formation process is performed with respect to the ceramic unsintered body which is easy to process, a cavity and a castellation can be formed comparatively easily. Therefore, according to this manufacturing method, the ceramic package of the means 1 and 2 can be manufactured relatively easily and efficiently.

  Hereinafter, the manufacturing method of the means 3 will be described.

  In the preparation step, a ceramic green body to be a ceramic substrate is prepared. A preferred example of the ceramic green body is a ceramic green sheet. The ceramic green sheet is produced, for example, by forming a slurry obtained by mixing ceramic raw material powder, an organic binder, a solvent, a plasticizer, and the like into a sheet shape.

  In the subsequent drilling step, a hole is formed in a corner portion of the cavity formation scheduled portion in the ceramic unsintered body. This hole is preferably formed at a position corresponding to the corner of the cavity formation scheduled portion, that is, at four spaced locations. Note that. The hole will later form part of the castellation. A method for forming such a hole is not particularly limited, and drilling, punching, laser processing, or the like can be employed depending on the application. The hole may be a through hole or a non-through hole.

  In the subsequent conductor portion forming step, a conductor portion is formed in the hole portion using a conventionally known method. Specifically, the conductor part is printed by using a through-hole printing technique to form a conductor part, or the conductor part is filled by using a via filling technique to form the conductor part.

  In the subsequent cavity and castellation simultaneous formation process, the cavity formation scheduled portion in the ceramic unsintered body is removed by machining. Then, by this machining, a cavity having a substantially rectangular shape in plan view is formed, and at that time, the hole and the part of the conductor part are notched, thereby providing the conductor part on the surface of the groove part. Form a castellation of structures.

  Examples of machining in this case include cutting, grinding, punching, and abrasive processing. Among these, cutting is preferable from the viewpoint of productivity and the like.

  When a cavity having a substantially rectangular shape in plan view is formed, a part of the hole and the conductor is cut away. For example, a case is assumed in which holes and conductors are formed at four spaced apart locations corresponding to the corners of the cavity formation scheduled portion. Each hole has a center point, and a rectangle formed when the center points are connected is defined as a “first virtual rectangle”. Considering the case where machining is performed along the outline of the first virtual rectangle and the inner region is removed, the ratio of the portion that remains without being removed is too large, and a castellation having a suitable cross-sectional shape is obtained. I can't. Therefore, it is difficult to secure a sufficient seal path in the castellation forming portion. Therefore, a rectangle that is slightly larger than the first virtual rectangle is assumed, and this is defined as a “second virtual rectangle”. Considering the case where machining is performed along the outline of the second virtual rectangle and the inner region is removed, the ratio of the portions that remain without being removed is moderately reduced. As a result, casters having suitable cross-sectional shapes are compared. Can be easily obtained. Therefore, it becomes easy to ensure a sufficient seal path in the castellation forming portion. In other words, assuming a rectangle (that is, a second virtual rectangle) defined when each vertex of the first virtual rectangle is offset by a predetermined amount in a direction away from each other, along the outline of the second virtual rectangle. Machining may be performed to remove the inner region. In addition, it is preferable that it is 0.75 times or more and 1.25 times or less of the radius of a hole as a suitable offset amount of the vertex of the 1st virtual rectangle, and especially 0.80 times or more and 1.20 times or less. More preferably. If the ratio is less than 0.75, the ratio of the portion that remains without being removed is too large, so that a sufficient seal path cannot be secured in the corner portion, and it is difficult to reduce the incidence of burrs at the edge of the castellation. On the other hand, if the ratio exceeds 1.25 times, the ratio of the portion that remains without being removed becomes too small, making it difficult to form a large conductor portion and making it difficult to achieve low resistance.

  In the subsequent firing step, the ceramic green body on which the cavity and the castellation are formed is fired to obtain a ceramic substrate. At this time, the conductor portion constituting the castellation is also sintered.

  As means 4 for solving the above-mentioned problem, a large number of product regions to be ceramic packages according to any one of claims 1 to 5 are arranged vertically and horizontally along a plane direction. There is a ceramic package for removal.

  As a suitable method (means 5) for manufacturing the multi-cavity ceramic package according to the means 4, a preparatory step of preparing a ceramic unsintered body to be a ceramic substrate, and the ceramic unsintered body Drilling process for forming a hole in the corner of the cavity formation planned part in the conductor, a conductor part forming process for forming a conductor part in the hole, and removing the cavity formation planned part in the ceramic unsintered body by machining Thus, a caster having a structure in which the cavity is formed in a substantially rectangular shape in plan view, and at the time, the hole and the conductor are partially cut away to provide the conductor on the surface of the groove. Cavity and castellation simultaneous forming step, and ceramic in which the cavity and castellation are formed There are provided methods for producing the large number ceramic package for up including a baking step of a ceramic substrate by firing the sintered body.

  Therefore, according to this manufacturing method, the cavity and the castellation can be formed simultaneously by removing the cavity formation scheduled portion by machining, so that an increase in man-hours can be prevented. Moreover, since this simultaneous formation process is performed with respect to the ceramic unsintered body which is easy to process, a cavity and a castellation can be formed comparatively easily. Therefore, according to this manufacturing method, the multi-cavity ceramic package of the means 4 can be manufactured relatively easily and efficiently.

  Hereinafter, a ceramic package 10 according to an embodiment of the present invention and a manufacturing method thereof will be described with reference to FIGS.

  As shown in FIGS. 1 to 3, the ceramic package 10 of the present embodiment is an apparatus for mounting a semiconductor element 21 typified by a SAW filter or the like. The ceramic substrate 11 constituting the ceramic package 10 is a rectangular flat plate member having an upper surface 12 and a lower surface 13. The ceramic substrate 11 has a two-layer structure including an upper ceramic sintered layer 14 and a lower ceramic sintered layer 15. In the present embodiment, the upper ceramic sintered layer 14 and the lower ceramic sintered layer 15 are both made of an alumina sintered body. In this embodiment, a two-layer structure is used, but a multilayer structure of three or more layers may be adopted.

  The ceramic substrate 11 includes a cavity 22 that opens at the upper surface 12. The cavity 22 of the present embodiment has a substantially rectangular shape in plan view, and its outer dimension is set to about 70% to 90% of the outer dimension of the ceramic substrate 11. The depth of the cavity 22 corresponds to the thickness of the upper ceramic sintered layer 14. At a plurality of locations on the bottom surface of the cavity 22, element mounting portions 23 made of a metallized layer of a refractory metal such as tungsten are formed. The semiconductor element 21 is joined to these element mounting portions 23 by soldering. An inner layer conductor pattern 28 made of a metallized layer is formed at the interface between the upper ceramic sintered layer 14 and the lower ceramic sintered layer 15. These inner layer conductor patterns 28 are connected to the respective element mounting portions 23.

  On the upper surface of the outer peripheral portion of the cavity 22 in the ceramic substrate 11, a sealing metallization layer 24 is provided so as to surround the cavity 22. On the metallized layer 24, a plating layer (not shown) and a brazing material layer (not shown) are provided, and a metal ring 25 is attached via the brazing material layer. A nickel-gold plating layer may be further formed with the metal ring 25 attached. On the metal ring 25, a metal cap 26 for closing the cavity 22 is attached. That is, the outer peripheral portion of the cavity 22 functions as a seal portion for blocking communication between the inside and outside of the cavity 22.

  A plurality of pad portions 27 made of a metallized layer are provided on the outer peripheral portion of the lower surface 13 of the ceramic substrate 11. These pad portions 27 are bonded to a plurality of substrate-side terminals when the ceramic package 10 is mounted on another substrate (not shown).

  As shown in FIGS. 1 to 5, the ceramic package 10 includes a plurality of two types of castellations (first castellation 31 and second castellation 41).

  The first castellation 31 has a structure in which a conductor portion 33 made of a metallized layer is provided on the surface of the concave groove portion 32, and is arranged at each corner portion on the outer peripheral surface of the ceramic substrate 11. These first castellations 31 electrically connect the inner layer conductor pattern 28 and the pad portion 27.

  On the other hand, the second castellation 41 has a structure in which a conductor portion 43 made of a metallized layer is provided on the surface of the concave groove portion 42, and is disposed on the side wall 48 of each corner portion of the cavity 22. And some or all of these 2nd castellations 41 have electrically connected metallized layer 24 and pad part 27 corresponding to a ground layer. In addition, it can be said that the cross-sectional shape as a whole of the 2nd castellation 41 of this embodiment is what is called a substantially crescent shape, and is not a half-moon shape at least.

  Here, the outline of the substantially rectangular cavity 22 in plan view is basically defined by the four sides 51, 51, 51, 51, and extension lines of two adjacent sides 51, 51 are adjacent to each other. Let the intersecting point be a virtual intersection P1 (see FIGS. 4 and 5). Then, a virtual center point P2 offset from the virtual intersection P1 in the center direction of the cavity 22 (the direction indicated by the arrow in FIGS. 4 and 5) is hypothesized, and a virtual circle 52 of radius R1 centered on the virtual center point P2 is hypothesized. Try it. At this time, an arc 53 that is an area outside the outline of the cavity 22 in plan view in the virtual circle 52 is assumed. The recessed groove portion 42 of the second castellation 41 of the present embodiment has a cross-sectional shape along the arc 53. In the present embodiment, the radius R1 of the virtual circle 52 is set to about 0.07 mm to 0.15 mm.

  For example, in the second castellation 41 shown in FIG. 4, the offset amount 54 of the virtual center point P2 with respect to the virtual intersection P1 is 0.88 times the radius R1 of the virtual circle 52. In the second castellation 41, the length of the arc 53 corresponding to the concave groove portion 42 is 190/360 of the circumferential length of the virtual circle 52. Similarly, in the second castellation 41 shown in FIG. 5, the offset amount 54 of the virtual center point P2 with respect to the virtual intersection P1 is 1.17 times the radius R1 of the virtual circle 52. In the second castellation 41, the length of the arc 53 corresponding to the concave groove portion 42 is 160/360, which is the circumferential length of the virtual circle 52. Accordingly, in FIGS. 4 and 5, both the offset amount 54 and the length of the arc 53 are set so as to be values within the preferred range in the present invention. Incidentally, in this embodiment, since the radius R1 of the virtual circle 52 is 0.07 mm to 0.15 mm, the circumferential length of the virtual circle 52 is 0.44 mm to 0.94 mm.

  Further, in the second castellation 41 shown in FIG. 4, the angle θ formed by the concave groove portion 42 having an arcuate cross section and the outline (ie, the side 51) in plan view of the cavity 22 is about 130 °. Yes. In the second castellation 41 shown in FIG. 5, the angle θ formed by the concave groove 42 having an arcuate cross section and the outline of the cavity 22 in plan view is about 140 °. Therefore, in FIG. 4 and FIG. 5, the angle θ is also set to a value within the preferred range in the present invention.

  Next, a method for manufacturing the ceramic package 10 having the above structure will be described with reference to FIGS.

  First, the preparatory process which prepares the ceramic unsintered body which should become the ceramic substrate 11 is implemented. Specifically, a slurry is prepared by mixing alumina powder, an organic binder, a solvent, a plasticizer, and the like. Then, this slurry is formed into a sheet shape by a conventionally known method (for example, a doctor blade method or a calender roll method) to produce two ceramic green sheets 64 and 65 as shown in FIG.

  In the subsequent drilling step, holes 71 to be a part of the second castellation 41 later are formed through each corner of the cavity formation scheduled portion 72 in the upper ceramic green sheet 64 that is a ceramic unsintered body ( (See FIGS. 7 and 8). These hole portions 71 may be formed by a conventionally known punching (punching) process, or may be formed by a technique such as laser processing or drilling. Further, another hole 75 that is to become the first castellation 31 later is formed at a position different from these holes 71, that is, a position on the planned cutting line of the product region.

  In the subsequent conductor portion forming step, conductor portions are formed in the holes 71 and 75, respectively. More specifically, first, via metallization filling is performed by a conventionally known paste printing apparatus to fill the hole 71 with the tungsten paste 77 (see FIG. 9). That is, the hole 71 is completely filled with the tungsten paste 77. Next, castellation printing is performed to attach tungsten paste 77 to the inner peripheral surface of hole 75. Therefore, the hole 75 does not have to be completely filled with the tungsten paste 77, and the center of the hole 71 is hollow. As described above, caster printing may be performed after via metallization filling, or after via metallization filling after castal printing. Then, a tungsten paste 77 is pattern printed on the ceramic green sheets 64 and 65 (see FIG. 10). These printed layers are portions that will later become the element mounting portion 23, the metallized layer 24, the pad portion 27, and the inner layer conductor pattern 28.

  In the subsequent cavity and castellation simultaneous forming step, the cavity formation scheduled portion 72 in the upper ceramic green sheet 64 which is a ceramic unsintered body is removed by cutting. And the cavity 22 of planar view substantially rectangular shape is formed by this cutting process (refer FIG. 11). At that time, the hole portion 71 and a part of the tungsten paste 77 (conductor portion 43) filled therein are cut out. As a result, the second castellations 41 having a structure in which the conductor portion 43 is provided on the surface of the concave groove portion 42 are formed at four locations.

  Here, it is assumed that the hole 71 and the conductor 43 are formed at four spaced locations corresponding to the corner of the cavity formation scheduled portion 72. As shown in FIG. 8, each hole 71 has a center point P3, and a rectangle formed when the center points P3 are connected is defined as a “first virtual rectangle 81”. Considering the case where machining is performed along the outline of the first virtual rectangle 81 and the inner region is removed, the ratio of the remaining portion that is not removed is too large, and the second castellation having a suitable cross-sectional shape is obtained. 41 cannot be obtained. Therefore, it is difficult to secure a sufficient seal path in the castellation forming portion. Therefore, a rectangle that is slightly larger than the first virtual rectangle 81 is assumed, and this is defined as a “second virtual rectangle 82”. Considering the case where machining is performed along the outline of the second virtual rectangle 82 and the inner region is removed, the ratio of the portion that remains without being removed is appropriately reduced. As a result, the second caster having a suitable cross-sectional shape is obtained. It is possible to obtain the adjustment 41 relatively easily.

  In the subsequent laminating step, the upper ceramic green sheet 64 is laminated on the lower ceramic green sheet 65, and a predetermined load is applied in the thickness direction by using a conventionally known laminating apparatus, thereby pressing and integrating them. A laminated body is formed (see FIG. 12).

  In the subsequent grooving step, break grooves 85 having a V-shaped cross section are formed in a lattice shape on the front and back surfaces of the laminate along the outline of the product region by using a conventionally known blade device (see FIG. 13). .

  Then, the baking process which heats this laminated body to the predetermined | prescribed temperature (for example, temperature of about 1500 degreeC-1800 degreeC) which an alumina can sinter is performed. After this firing, the lower ceramic green sheet 65 and the upper ceramic green sheet 64 are sintered, and the ceramic substrate 11 having the cavity 22 is obtained. Further, the element mounting portion 23, the metallized layer 24, the pad portion 27, the inner layer conductor pattern 28, the conductor portion 43 of the second castellation 41, and the like are formed by sintering the tungsten paste 77. It can be understood that the product in this state is a multi-cavity ceramic package 101 having a structure in which a plurality of product regions to be the ceramic package 10 are arranged vertically and horizontally along the plane direction (see FIG. 14).

  Further, after performing electrolytic nickel plating, formation of a silver brazing material layer, brazing of a metal ring 25, electrolytic nickel-gold plating, etc. on the metallized layer 24 of the multi-cavity ceramic package 101 of FIG. Divide along the break groove 85. Then, a large number of ceramic packages 10 as individual products can be obtained simultaneously. During the break process, stress is likely to be applied to the outer periphery of the package. Normally, cracks are likely to occur around the second castellation 41, but no cracks were generated in this embodiment. Then, after such a break step, the semiconductor element 21 is mounted in the cavity 22 of the ceramic package 10 and the metal cap 26 is attached, whereby the element-equipped ceramic package shown in FIG. 1 is completed.

  Therefore, according to the present embodiment, the following effects can be obtained.

  (1) In the ceramic package 10, the second castellation 41 having the above-described cross-sectional shape is disposed on the side wall 48 at the corner of the cavity 22 in addition to being slightly offset in the center direction of the cavity 22. For this reason, a sufficient seal path can be secured in the castellation forming portion, and the leak occurrence rate can be kept low. Therefore, the ceramic package 10 having excellent sealing properties can be obtained.

  (2) In this ceramic package 10, both the offset amount 54 of the virtual center point P2 and the length of the arc 53 with reference to the virtual intersection P1 are set to be values within the preferred range of the present invention. . Therefore, the resistance of the second castellation 41 can be reduced, a sufficient seal path can be secured, and the occurrence rate of burrs at the edge 45 can be reduced. Therefore, the yield is improved and the deburring operation is not required, so that the cost can be reduced.

  (3) In the case of the second castellation 41 of the ceramic package 10, the angle θ formed by the concave groove portion 42 and the outline of the cavity 22 in plan view is a value within a preferable range of 100 ° to 140 °. Is set to For this reason, the incidence rate of burrs at the edge 45 of the second castellation 41 can be kept low, and the yield can be improved and the cost can be reduced.

  (4) Also, according to the method for manufacturing the ceramic package 10 of the present embodiment, the cavity 22 and the second castellation 41 can be formed simultaneously by removing the cavity formation scheduled portion 72 by machining, thereby increasing the number of steps. Can be prevented. Moreover, since this simultaneous formation process is performed with respect to the ceramic unsintered body which is easy to process, the cavity 22 and the 2nd castellation 41 can be formed comparatively easily. Therefore, according to this manufacturing method, the ceramic package 10 can be manufactured relatively easily and efficiently.

  In addition, you may change embodiment of this invention as follows.

  For example, although the cavity 22 and the second castellation 41 are formed at the same time in the embodiment, they may be formed separately. For example, after the drilling step, the following steps are performed without performing the conductor portion forming step. That is, the cavity formation scheduled portion 72 in the ceramic unsintered body is removed by machining so as to form the cavity 22 having a substantially rectangular shape in plan view, and a part of the hole portion 71 is notched at that time. To do. Next, a conductor part forming step is performed to form the conductor part 43 in the hole 71 (that is, the recessed groove part 42) remaining without being cut out, thereby forming the second castellation 41 having a desired structure.

  Next, the technical ideas grasped by the embodiment described above are listed below.

  (1) A substantially rectangular cavity in plan view capable of mounting an element on a ceramic substrate is formed, and a conductor having a conductor portion on the surface of the groove portion, and a castellation having a substantially crescent-shaped cross section as a whole A ceramic package formed on a side wall of a corner portion of the cavity.

  (2) A ceramic package in which a substantially rectangular cavity in plan view capable of mounting elements on a ceramic substrate is formed, and a castellation having a structure in which a conductor is provided on the surface of the groove is formed on the side wall of the corner of the cavity. A step of preparing a ceramic unsintered body to be a ceramic substrate including a plurality of product regions, and forming a hole in a corner part of a cavity formation scheduled part in the ceramic unsintered body Forming a conductor part in the hole part, and forming a cavity part in the ceramic unsintered body by machining to form a substantially rectangular cavity in plan view At the same time, by cutting out a part of the hole and the conductor part, the conductor part is provided on the surface of the groove part. A cavity and castellation simultaneous forming step for forming a castellation, a grooving step for forming break grooves in a lattice shape along the outline of the product region in the ceramic green body, and the cavity and the castellation A method for manufacturing a ceramic package, comprising: a firing step of firing a formed ceramic unsintered body to form a ceramic substrate; and a break step of dividing the ceramic substrate along the break grooves into pieces.

1 is a schematic cross-sectional view showing a ceramic package of an embodiment embodying the present invention. The schematic plan view of the ceramic substrate which comprises a ceramic package. The partial expansion perspective view which shows the 2nd castellation in a ceramic package. The partial enlarged plan view which shows the 2nd castellation in a ceramic package. The partial enlarged plan view which shows the 2nd castellation in a ceramic package. The schematic sectional drawing for demonstrating the manufacturing method of a ceramic package. The schematic sectional drawing for demonstrating the manufacturing method of a ceramic package. The schematic plan view for demonstrating the manufacturing method of a ceramic package. The schematic sectional drawing for demonstrating the manufacturing method of a ceramic package. The schematic sectional drawing for demonstrating the manufacturing method of a ceramic package. The schematic sectional drawing for demonstrating the manufacturing method of a ceramic package. The schematic sectional drawing for demonstrating the manufacturing method of a ceramic package. The schematic sectional drawing for demonstrating the manufacturing method of a ceramic package. The schematic sectional drawing for demonstrating the manufacturing method of a ceramic package. The schematic sectional drawing for demonstrating the manufacturing method of a ceramic package.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Ceramic package 11 ... Ceramic substrate 21 ... Semiconductor element 22 as element 22 ... Cavity 41 ... (2nd) castellation 42 ... Groove part 43 ... Conductor part 48 ... Side wall of cavity 51 ... Side 52 ... Virtual circle 53 ... Arc 54 ... Offset amount 64, 65 ... Ceramic green sheet as ceramic unsintered body 71 ... Hole portion 72 ... Cavity formation scheduled portion P1 ... Virtual intersection P2 ... Virtual center point θ ... Angle

Claims (8)

In a ceramic package in which a cavity having a substantially rectangular shape in plan view capable of mounting an element on a ceramic substrate is formed, and a castellation having a structure in which a conductor portion is provided on the surface of the concave groove portion is formed on the side wall of the cavity,
The concave groove is
Disposed on the side wall of the corner of the cavity;
Of the four sides that define the outer shape of the cavity in plan view, a point where the extension lines of two adjacent sides intersect with each other is a virtual intersection, and a virtual center point that is offset from the virtual intersection in the center direction of the cavity. A ceramic package characterized in that when a virtual circle as a center is imagined, the virtual circle has a cross-sectional shape along an arc that is a region outside the outline of the cavity in plan view.   2. The ceramic package according to claim 1, wherein an offset amount of the virtual center point with respect to the virtual intersection is 0.75 times or more and 1.25 times or less the radius of the virtual circle.   2. The ceramic package according to claim 1, wherein a length of the arc corresponding to the concave groove is 150/360 or more and 240/360 or less of a circumferential length of the virtual circle.   The angle formed by the concave groove portion having a circular arc shape in cross section and the outline of the cavity in plan view is 100 ° or more and 140 ° or less, according to any one of claims 1 to 3. Ceramic package. In a ceramic package in which a cavity having a substantially rectangular shape in plan view capable of mounting an element on a ceramic substrate is formed, and a castellation having a structure in which a conductor portion is provided on the surface of the concave groove portion is formed on the side wall of the cavity,
The concave groove portion is disposed on the side wall of the corner portion of the cavity, and the cross-sectional shape thereof has an arc shape,
The ceramic package, wherein an angle formed by the concave groove portion having an arcuate cross section and an outline of the cavity in plan view is 100 ° or more and 140 ° or less. A method for producing a ceramic package according to any one of claims 1 to 5,
A preparation step of preparing a ceramic green body to be a ceramic substrate;
Drilling step of forming a hole in the corner portion of the cavity formation planned portion in the ceramic green body,
A conductor portion forming step of forming a conductor portion in the hole portion;
The cavity formation scheduled part in the ceramic unsintered body is removed by machining to form a substantially rectangular cavity in plan view, and at that time, a part of the hole part and the conductor part is cut out. Then, a cavity for forming a castellation having a structure in which the conductor portion is provided on the surface of the groove portion and a castellation simultaneous forming step,
A method for producing a ceramic package, comprising: firing a ceramic unsintered body in which the cavity and the castellation are formed to form a ceramic substrate.   6. A multi-cavity ceramic package, wherein a plurality of product regions to be the ceramic package according to claim 1 are arranged vertically and horizontally along a plane direction. A method of manufacturing a multi-cavity ceramic package according to claim 7,
A preparation step of preparing a ceramic green body to be a ceramic substrate;
Drilling step of forming a hole in the corner portion of the cavity formation planned portion in the ceramic green body,
A conductor portion forming step of forming a conductor portion in the hole portion;
The cavity formation scheduled part in the ceramic unsintered body is removed by machining to form a substantially rectangular cavity in plan view, and at that time, a part of the hole part and the conductor part is cut out. Then, a cavity for forming a castellation having a structure in which the conductor portion is provided on the surface of the groove portion and a castellation simultaneous forming step,
A method for producing a multi-cavity ceramic package, comprising a firing step of firing the ceramic green body on which the cavity and the castellation are formed to form a ceramic substrate.

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