JP2018181964A - Ceramic substrate and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ceramic substrate in which a wide metallized layer along a periphery of a flat surface of a substrate body consisting of ceramic and a belt-like metallized part along a mounting region side on a top face thereof are accurately formed at required positions and a metal frame is firmly bonded at an upper side of the wide metallized layer and the belt-like metallized part.SOLUTION: The present invention relates to a ceramic substrate 1a comprising: a substrate body 2a consisting of ceramic c1 and including front and rear faces 3 and 4 of which the contour in a planar view is rectangular and which are opposite to each other, and a side face 5 which is positioned between the front and rear faces; an electronic component mounting region 9 which is positioned closer to a center of the front face 3; and a metallized layer 12 which is positioned outside of the mounting region 9 and formed in a rectangular frame shape in a planar view along an outer peripheral part of the front face 3. On a top face of the metallized layer 12, a recess 13 is formed along a side of the mounting region 9 rather than a side of the side face 5. The top face of the metallized layer 12 includes a belt-like metallized part 16 which is formed along each side of the metallized layer 12. The belt-like metallized part 16 is overlapped with the recess 13 at least partially in a side view on the top face of the metallized layer 12.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a ceramic substrate having a cavity formed by a metal frame on at least the surface side of a substrate body made of ceramic, and a method of manufacturing the same.

For example, in a box-shaped package body made of ceramic, a frame-shaped first metallized layer having a wide vertical cross section is formed along the rectangular frame-shaped surface where the cavity is opened, and the inward and outward directions on the upper surface of the first metallized layer Forming a second metallized layer in a frame shape having a narrow (striped) vertical cross section along the middle position of the second metallized layer and disposed on the upper surface of the first metallized layer on the inner and outer peripheral sides of the second metallized layer. There has been proposed a ceramic package in which a rectangular frame-shaped metal frame is joined to the upper side of the brazing material and the second metallized layer through the brazing material provided (see, for example, Patent Document 1).
Since the upper surface of the first metallized layer in the ceramic package is flat, the second metallized layer can be formed with high accuracy along a predetermined position in the inner and outer direction of the first metallized layer.

  However, in order to meet the demand for downsizing and thinning of ceramic packages in recent years, the width in the inward and outward direction along the rectangular frame-like surface surrounding the opening of the cavity or along the periphery of the flat surface. When the first metallized layer having a relatively narrow width is formed, the surface of the first metallized layer tends to be a curved surface which is gently curved and lowered from the outer peripheral side toward the cavity side. Therefore, the width of the curved surface on the upper surface of the first metallized layer at the time of manufacturing the ceramic package is at the time of manufacturing the ceramic package due to the gradient on the cavity side on the inner peripheral side becoming larger than the gradient on the outer peripheral side. When the narrow strip-like second metallized layer is formed of a conductive paste, the conductive paste may be displaced to the cavity side or may drop. Therefore, it has been considered extremely difficult to obtain a small ceramic package in which a metal frame is firmly joined to the upper side of the first and second metallized layers by brazing.

JP, 2013-138070, A (pages 1-16, FIGS. 1-11)

  The present invention solves the problems described in the background art, and forms a wide metallized layer along the surface of the substrate body made of ceramic (that is, around the flat surface or a rectangular frame-like surface having an open cavity). A ceramic substrate in which narrow strip-like metallized portions having a narrow width along the cavity side or mounting region side on the upper surface of the metallized layer are precisely formed at required positions, and a metal frame is firmly bonded to them above them; It is an object to provide a method for manufacturing the same.

Means for Solving the Problems and Effects of the Invention

In order to solve the above problems, the present invention forms a recess along the mounting area side of the upper surface on a curved upper surface of a wide metallized layer formed along the periphery of the flat surface of the substrate body. The invention is conceived on the idea that at least a part of the recess and a narrow strip-like metallized layer overlap in a side view, or a band-like metallization layer is formed on the outer peripheral side of the recess.
That is, the ceramic substrate according to the present invention (claim 1) is a substrate body made of ceramic, having a rectangular outer shape in plan view and having opposing front and back surfaces, and a side surface located between the front and back surfaces. And a plane formed along the outer peripheral portion of the surface of the substrate main body located outside the mounting region in plan view, and the mounting region of the electronic component positioned at least on the center side of the surface of the substrate main body in plan view A ceramic substrate comprising a metallized layer having a rectangular frame shape, wherein a recess is formed on the upper surface of the metallized layer along the mounting region side more than the side surface side, and the upper surface of the metallized layer And a strip-shaped metallized portion formed along each side of the metallized layer, wherein the strip-shaped metallized portion overlaps at least a part with the recess in a side view on the upper surface of the metallized layer. And have either or are formed between the concave portion and the side surface of the substrate main body, characterized in that.

According to this, it is possible to achieve the following effects (1) to (3).
(1) The concave portion is formed on the upper surface of the metallized layer along the position closer to the mounting area than the side surface side, and the upper surface of the metallized layer is formed along each side of the metallized layer A strip-shaped metallized portion is provided, and the strip-shaped metallized portion at least partially overlaps the recess in a side view on the upper surface of the metallized layer, or is formed between the recess and the side surface of the substrate body It is done. As a result, the unbaked strip-shaped metallized portion made of a conductive paste at the time of manufacture is formed to be extremely deviated to the mounting region side or dropped to the mounting region side due to the concave portion. In addition, it is formed in a rectangular shape in a plan view at a position approximately directly above the recess or at the side surface side with respect to the recess, and the entire circumference is formed at substantially the same level in a side view.
(2) Due to the above effect (1), a metal frame to be described later is provided above the band-like metallized portion and the metallized layer on the inner and outer peripheral sides thereof via a bonding material (for example, a brazing material) It becomes possible to join firmly and precisely along the circumference.
(3) Due to the effect (1), narrowing of the mounting area can be suppressed based on the band-like metallized portion being shifted to the mounting area side.
(4) Due to the above effect (2), after a required electronic component is mounted on the mounting area later, a metal cover plate can be easily welded by seam welding along the upper surface of the metal frame, The inside of the cavity surrounded by the metal frame can be reliably sealed.

The ceramic constituting the substrate main body is made of, for example, a high temperature sintered ceramic such as alumina, aluminum nitride or mullite, or a low temperature sintered ceramic such as a crow-ceramic.
Further, at least the surface of the substrate main body is a flat surface having a rectangular shape in a plan view, or a planar shape having a rectangular frame shape in a plan view surrounding the opening of the cavity opening on the center side of the surface. The substrate body is composed of at least one ceramic layer when the surface is flat, and in the mode having the cavity, two or more ceramic layers are laminated.
Furthermore, the mounting area is located on the center side in plan view of the surface formed by the flat surface of the substrate body, or the bottom surface of the cavity is open on the surface of the substrate body having a rectangular frame shape in plan view. Almost the entire area of A plurality of mounting pads are formed in the mounting area.
The metallized layer and the band-like metallized portion may use tungsten or molybdenum when the ceramic of the substrate body is the high temperature fired ceramic, and copper or silver when the low temperature fired ceramic is used.
In addition, the concave portion includes, for example, a V-shaped cross section in a side view or a stepped portion including an adjacent inclined surface and a horizontal surface.

Further, according to the present invention, the upper surface of the metallized layer is an upwardly convex first curved surface whose height gradually decreases from the side surface side of the substrate body toward the concave portion, the concave portion, and the mounting area. Also included is a ceramic substrate (Claim 2), which is located between and has an upwardly convex second curved surface whose width in plan view is narrower than the first curved surface.
According to this, since the strip-like metallized portion formed on the upper surface of the metallized layer is not formed at least by the concave portion so as to be shifted to the mounting region side or dropped off, the effects (1) to (5) It is possible to obtain 4) with certainty.
The first curved surface exhibits a continuous curve in which the side surface side of the substrate main body is the highest portion and the concave portion side is the lowest portion in side view, and the second curved surface is the highest portion in the concave portion side in side view And has a continuous-shaped curve in which the mounting area side is the lowest.

Furthermore, according to the present invention, the rectangular frame shape in plan view is provided above the upper surface of the metallized layer via the bonding portion disposed on the mounting region side of the strip-like metallized portion and the side surface side of the substrate main body. Also included is a ceramic substrate (Claim 3) to which the metal frame of 4 is bonded.
According to this, the metal frame makes the entire circumference the same level via the joint portion above the strip-shaped metallized portion and above the mounting region side of the metallized layer and the side surface side of the substrate body. Since the bonding is performed reliably, the effect (4) can be reliably obtained.
The metal frame is, for example, Kovar (Fe-29% Ni-17% Co), 42 alloy (Fe-42% Ni), or 194 alloy (Cu-2.3% Fe-0.03% P). And so on.
Further, the joint portion is formed, for example, by brazing, and silver brazing (Ag-15% Cu) is applied to a brazing material used for the brazing, for example.

On the other hand, the method for manufacturing a ceramic substrate according to the present invention (claim 4) is a method for manufacturing a ceramic substrate according to the present invention, wherein a plurality of substrate regions to be the substrate main body In the sheet, a plan view is rectangular on the outer periphery side of the mounting area of the electronic component on the surface of each of the two substrate areas and along the planned cutting surface, straddling the planned cutting surface dividing the two adjacent substrate regions. Forming an unbaked metallized layer which is frame-shaped and convex upward, and in the upper surface of the unbaked metallized layer in plan view, along the mounting area side rather than the planned cutting surface side for each substrate area A step of forming a recess, and in the upper surface of the metallized layer, at each position where at least a portion overlaps the recess in a side view, or the recess and the surface to be cut The position of each between, and forming a strip-shaped metallization of unfired, and characterized in that.
According to the manufacturing method as described above, it becomes possible to reliably manufacture the ceramic substrate exhibiting the effects (1) to (4) (effect (5)).

The planned cutting surface is a virtual cross section set in the ceramic green sheet for multiple-piece preparation, and the ceramic substrate is fired when the green sheet is fired and divided into individual substrate regions. Each side surface of the substrate body.
Further, the upper surface of the unbaked metallized layer exhibits a continuous curve having a maximum at the planned cutting surface side in a side view and a minimum at the mounting region side for each of the adjacent substrate regions.
Furthermore, after the step of forming the unbaked strip-shaped metallized portion, the step of firing the green sheet having the metallized layer and the strip-shaped metallized portion, the upper surface of the metallized layer after firing and the strip-shaped metallized after firing Step of plating a metal film (for example, nickel and gold) on the exposed surface of the portion, the step of singulating each substrate region, and firing above the upper surface of the metallized layer in each substrate body A metal frame having a rectangular frame shape in a plan view and a rectangular shape in a side view through a bonding portion (for example, a brazed portion) disposed on the mounting region side of the strip metallized portion and the side surface side of the substrate main body And a step of joining the

Further, in the present invention, the step of forming the concave portion is performed by pressing the pressing frame mold along the mounting area side with respect to the planned cutting surface side for each of the substrate areas on the upper surface of the metallized layer. A method of manufacturing a ceramic substrate (claim 5) is also included.
According to this, since the concave portion can be reliably formed at the position in the metallized layer, the effect (5) can be reliably exhibited.
The cross section of the lower end (tip) side has an acute V-shaped cross section on the lower end (tip end) side or a narrow horizontal surface at the tip, and the whole has a lattice frame shape in plan view.

FIG. 1 is a plan view showing a form of ceramic substrate according to the present invention and partially including a horizontal cross section. (A) is a partial vertical cross-sectional view along the arrow of XX in FIG. 1, (B) is a partial vertical cross-sectional view similar to (A) having strip-shaped metallized portions of different forms. (A)-(E) are schematic which shows each manufacturing process for obtaining the said ceramic substrate. (A), (B) is the schematic which shows each manufacturing process following FIG.3 (E). (A) is a partial vertical cross-sectional view showing the vicinity of a recess having a different form, and (B) is a partial vertical cross-sectional view showing a strip-like metallized portion formed so as to partially overlap with the recess. (A) is a vertical cross-sectional view showing a ceramic substrate in a form different from the above, (B) is an enlarged view of a dashed dotted line portion B in (A).

Hereinafter, modes for carrying out the present invention will be described.
FIG. 1 shows a plan view including a horizontal cross section in part with respect to a ceramic substrate 1a according to one embodiment of the present invention, and FIG. 2 (A) shows a partial vertical along the arrow of XX in FIG. FIG.
The ceramic substrate 1a is made of a ceramic layer c1 as shown in FIGS. 1 and 2A, and has a rectangular (rectangular) outer shape in plan view, and a surface 3 and a back surface 4 (not shown) facing each other. 3 and a flat plate-shaped substrate body 2a having side surfaces 5 of four sides located between the back surface 4 and a virtual electronic component (not shown) for the center side of the surface 3 of the substrate body 2a A mounting area 9 and a metallized layer 12 formed along the outer peripheral portion of the surface 3 located outside the mounting area 9 in a plan view, and having a rectangular frame shape in a plan view.

The substrate body 2a is made of, for example, a single-layer ceramic layer c1 such as alumina. Further, on the center side of the surface 3 of the substrate body 2a inside the mounting area 9 in a plan view, a pair of (plural) mounting pads 10 for electrically connecting with an electronic component (not shown) to be mounted later is provided. It is formed. Wiring (not shown) for electrolytic metal plating is formed on the front surface 3 or the back surface 4 of the substrate body 2a.
Furthermore, as shown in FIG. 2A, the upper surface of the metallized layer 12 is gradually lowered in height and convex upward from the side surface 5 side of the substrate body 2a toward the mounting region 9 side. It consists of a first curved surface r1 and a second curved surface r2 located between the first curved surface r1 and the mounting area 9 side and having a width in plan view narrower than the first curved surface r1 and upwardly convex. ing. Between the first curved surface r1 and the second curved surface r2 and on the mounting region 9 side of the metallized layer 12 in plan view, a recess 13 having a substantially V-shaped vertical cross section is formed around the entire periphery of the metallized layer 12. It is formed along.
The outer surface of the metallized layer 12 is flush with the side surface 5 of the substrate body 2a.

As shown in FIGS. 1 and 2A, a rectangular frame shape in plan view is formed almost right above the recess 13, and the width is narrower than the metallized layer 12, and the vertical cross section is substantially semicircular. A strip-shaped metallized layer 16 is formed along the entire circumference of the recess 13.
The conductors such as the mounting pad 10, the metallized layer 12, and the belt-like metallized layer 16 are mainly made of tungsten (hereinafter, simply described as W) or molybdenum (hereinafter, simply described as Mo).
Further, as shown in FIG. 2B, the strip-shaped metallized portion 16 is formed between the recess 13 and the side surface 5 side of the substrate body 2a in the first curved surface r1 on the upper surface of the metallized layer 12 The form which is being carried out may be sufficient.

Furthermore, as shown in FIGS. 1 and 2A and 2B, the strip-like metallized portion 16 is formed above the upper surface (the first curved surface r1, the recess 13 and the second curved surface r2) of the metallized layer 12 The vertical cross section is rectangular (rectangular) through the joint 18 by brazing disposed on the side of the mounting region 9 and the joint 19 by brazing disposed on the side 5 of the substrate body 2a. And a metal frame 22 having a rectangular frame shape in plan view is joined. The metal frame 22 is made of, for example, 42 alloy or 194 alloy. A cavity including the mounting area 9 is formed on the surface 3 of the substrate body 2 a surrounded by the metal frame 22, the metallized layer 12, and the brazing part 18.
After an electronic component (not shown) is mounted on the mounting area 9 on the upper surface of the metal frame 22, a cover plate 30 made of, for example, a flat plate made of metal is joined by seam welding or the like. As a result, the electronic component can be reliably sealed from the outside.

  According to the ceramic substrate 1a as described above, the recess 13 is formed on the upper surface of the metallized layer 12 along the mounting region 9 side of the side surface 5 of the substrate body 2a, and the upper surface of the metallized layer 12 is formed. Has a strip-like metallized portion 16 formed along each side, and the strip-like metallized portion 16 partially overlaps the recess 13 in a side view on the upper surface of the metallized layer 12 or It is formed between the recess 13 and the side 5 side. As a result, the unbaked strip-like metallized portion 16 made of a conductive paste is not formed by the concave portion 13 toward the mounting region 9 side by the concave portion 13 during manufacturing, nor is it formed to hang down. At a required position substantially immediately above 13 or on the side surface 5 side with respect to the recess 13, the planar view is rectangular and the entire circumference is formed at substantially the same level in the side view.

Therefore, the metal frame 22 can be firmly and accurately joined along the entire circumference of the strip-like metallized portion 16 and the metallized layer 12 on the inner and outer peripheral sides thereof via the bonding portions 18 and 19. . Furthermore, after the required electronic components are mounted on the mounting area 9 later due to the metal frame 22, the metal cover plate 30 can be easily welded by seam welding along the upper surface of the metal frame 22. The inside of the cavity surrounded by the metal frame 22 can be reliably sealed.
Therefore, according to the ceramic substrate 1a, the effects (1) to (4) can be exhibited. The substrate body 2a may have a form in which a plurality of ceramic layers are stacked and an inner layer wiring layer including for plating is provided between the ceramic layers.

Hereinafter, a method of manufacturing the ceramic substrate 1a will be described.
Alumina powder, a binder resin, a plasticizer, a solvent, etc. are compounded beforehand to prepare a ceramic slurry, and the ceramic slurry is formed into a sheet by a doctor blade method, as shown in FIG. As described above, a plurality of substrate regions 24 to be the ceramic layer c1 for each of the substrate bodies 2a are vertically and horizontally adjacent to each other in plan view, and have a facing surface 3 and a back surface 4 in a multi-cavity size. A ceramic green sheet (hereinafter simply referred to as a green sheet) g1 was prepared. The boundary between the substrate regions 24 adjacent to each other and the boundary between the substrate region 24 located on the outer peripheral side and the ears (not shown) located on the outer side in plan view are divided by a virtual planned cutting surface 25 ing.

Then, a punching process is performed at a predetermined position in each of the substrate regions 24 of the green sheet g1 to form a via hole (not shown) penetrating between the front surface 3 and the back surface 4, and in each via hole The conductive paste containing W powder or Mo powder was filled. As a result, as shown in FIG. 3B, unfired via conductors 21 were formed at each of the predetermined positions.
Next, the same conductive paste as described above was screen-printed for each required pattern for each of predetermined positions on the front surface 3 and the back surface 4 for each of the substrate regions 24.
As a result, as shown in FIG. 3B, a pair of unbaked mounting pads 10 is formed on the front surface 3 of each substrate region 24, and the back surface 4 of each of the substrate regions 24 is not yet formed. A plurality of external connection terminals 20 which are fired are formed. The external connection terminal 20 and the mounting pad 10 are individually connected via the via conductor 21.

Furthermore, the same conductive paste was screen-printed with a predetermined width on the surface 3 side of the green sheet g1 and along each of the planned cutting surfaces 25 for dividing the boundaries between the product regions 24. As a result, as shown in FIGS. 3B and 3C, it has an arc-shaped curved surface (upper surface) r whose vertical cross section is convex upward on the surface 3 side along each of the planned cutting surfaces 25. A bow-shaped and unfired metallized layer 11 was formed. The metallized layer 11 is formed in a lattice shape which vertically and horizontally intersects each other in plan view along each of the planned cutting surfaces 25.
FIG. 3C is an enlarged view of a dashed-dotted line portion C in FIG. 3B, and the surface to be cut 25 extends also to the inside of the metallized layer 11.
Next, as shown in the upper part of FIG. 3C, the above-mentioned metallizing is a pressing frame mold 26 having a V shape (sharp acute angle) at the lower end (tip) side in a vertical cross section and a lattice frame shape in plan view. Each layer 11 is pressed downward with respect to the position on the side of the mounting area 9 including the mounting pad 10 on each adjacent product area 24.

As a result, as shown in FIG. 3D, on the upper surface of each of the metallized layers 11, the left and right pairs having a V-shaped cross section along each of the mounting region 9 sides of each pair of adjacent product regions 24. The recess 13 of the
At the same time, as shown in the figure, the upper surface of the metallized layer 11 located between the planned cutting surface 25 and the recess 13 is an upward convex that gradually decreases from the planned cutting surface 25 toward the recess 13. The upper surface of the metallized layer 11 which becomes the first curved surface r1 and is located between the recessed portion 13 and the mounting region 9 side has a width in plan view narrower than the first curved surface r1 and the recessed region 13 to the mounting region 9 It has become the upward convex 2nd curved surface r2 which becomes gently low toward the side.

Next, the same conductive paste as described above was screen-printed along the longitudinal direction (front-rear direction in the drawing) of the pair of left and right recesses 13 on the upper surface of the metallized layer 11. As a result, as shown in FIG. 3E, the strip-shaped metallized portion 16 having a semicircular vertical cross section is formed along the entire circumference of the metallized layer 11 along almost directly above each recess 13. In the form of a rectangular frame. The strip-like metallized portion 16 may be formed by dipping the conductive paste (not shown).
In the meantime, a plurality of plating electrodes are formed on the outer side of the not-shown ear portion located on the peripheral side of the green sheet g1. The plating electrode is individually electrically connected to the external connection terminal 20 for each of the substrate regions 24 via, for example, a plating wiring (not shown) formed along the back surface 4.

Further, the green sheet g1 on which the mounting pad 10, the metallized layer 11 having the concave portion 13, the external connection terminal 20, and the via conductor 21 were formed was heated and degreased and fired. As a result, the green sheet g1 was fired to a large-sized ceramic layer c1 for preparing a large number of components, and the conductors such as the mounting pad 10 and the metallized layer 11 were also fired at the same time.
Next, the ceramic layer c1 having a fired conductor such as the mounting pad 10 and the metallized layer 11 is sequentially immersed in an electrolytic nickel plating bath and an electrolytic gold plating bath (not shown) to carry out electrolytic nickel plating and electrolytic gold plating. It applied sequentially. As a result, for each surface of the mounting pad 10, the metallized layer 11, the strip-like metallized portion 16, and the external connection terminal 20 exposed to the outside, a nickel film and a gold film (not shown) having a required thickness are provided. It was sequentially coated.

Furthermore, dicing processing is performed by sequentially inserting a circular blade (not shown) rotating at a high speed along each of the ceramic layer c1 and the surface 25 to be cut of the metallized layer 11 in order to insert the ceramic layer c1 into the substrate region 24. It was divided into each.
As a result, as shown in FIG. 4A, the product region 24 becomes the substrate body 2a having the facing surface 3 and the back surface 4 and the side surface 5 located between these four sides. At the same time, the metallized layer 11 has a cross-sectional shape which is about half that of the metallized layer 11 and is a pair of metallized layers 12 which are symmetrical. At this time, the planned cutting surface 25 is the side surface 5 of each adjacent substrate body 2 a and the outer surface of the metallized layer 12 flush with the side surface 5.
Then, as illustrated on the left side of FIG. 4B, a metal frame 22 having a rectangular frame shape in plan view and a rectangular vertical cross section is prepared above the metallized layer 12 and the strip metalized portion 16, and This was placed on the upper surface of the strip-shaped metallized portion 16. The brazing material layer 17 is bonded to the entire bottom surface of the metal frame 22 in advance.
The metal frame 22 is made of, for example, 42 alloy, and the brazing material layer 17 is made of, for example, silver solder (Ag-15% Cu alloy).

In a state where the metal frame 22 having the brazing material layer 17 on the bottom surface is placed on the upper surface of the strip-like metallized portion 16, the substrate body 2 a having the metallization layer 12 and the like is heated to After melting the silver solder, it was cooled to around normal temperature.
As a result, as illustrated on the right side of FIG. 4B, the brazing material layer 17 becomes a bonding portion 18 located between the second curved surface r2 of the metallized layer 12 and the bottom surface of the metal frame 22. The bonding portion 19 positioned between the first curved surface r1 of the metallized layer 12 and the bottom surface of the metal frame 22 solidified. Therefore, the metal frame 22 is firmly brazed (joined) in the peripheral portion of the surface 3 of the substrate body 2a and above the metallized layer 12 while maintaining substantially the same level along the entire circumference.
As a result of passing through the above steps, a plurality of the ceramic substrates 1a were obtained.

In addition, the ceramic substrate 1a straddles the upper side of the pair of mounting pads 10 located in the mounting area 9 and a required electronic component (for example, an IC chip) is mounted and the metal frame The metal lid plate 30 is joined to the upper surface of the base plate 22 by seam welding.
According to the method of manufacturing the ceramic substrate 1a described above, the plurality of ceramic substrates 1a having the effects (1) to (4) can be reliably manufactured (effect (5)).
The green sheet g1 may be prepared in advance as a two-layered green sheet, and an inner layer wiring including a plating wiring may be formed between the two, and then laminated.
Further, as shown in FIG. 2B, the strip-shaped metallized portion 16 is the first curved surface located between the recess 13 in the upper surface of the metallized layer 12 and the side surface 5 side of the substrate body 2a. You may form in the arbitrary positions on r1.

FIG. 5A is a partial vertical cross-sectional view showing the vicinity of the metallized layer 12 in which the recess 14 different from the recess 13 is formed. As shown in the figure, the concave portion 14 is a flat surface having a substantially horizontal surface on the second curved surface r2 side, and a curved surface or an inclined surface having a small first curved surface r1 side, and has a sectional shape of the step as a whole. . The step-shaped recess 14 is formed by pressing a pressing frame having a horizontal surface at the lower end (tip) with respect to the upper surface (curved surface r) of the unfired metallized layer 11.
FIG. 5B is a partial vertical cross-sectional view similar to the above, in which the strip-like metallized layer 16 is formed substantially right above the recess 14. In the manufacturing method, the conductive paste for forming the strip-like metallized portion 16 is formed on the first curved surface r1 substantially immediately above the recess 14 or on the outer peripheral side of the recess 14 as shown in the same manner. Even if the conductive paste is formed, the conductive paste is surely prevented from being shifted to the side of the second curved surface r2 or falling down by the concave portion 14.
Therefore, the effects (1) to (4) can be obtained even with the ceramic substrate 1a having the metallized layer 12 including the concave portion 14 and the strip-like metallized portion 16, and the effect can be reliably obtained by the manufacturing method described above. It is possible to play (5).

FIG. 6 (A) is a vertical sectional view showing a ceramic substrate 1b having a form different from the above, and FIG. 6 (B) is an enlarged view of a dashed dotted line portion B in the above (A).
The ceramic substrate 1b is formed by laminating upper and lower ceramic layers c1 and c2 as shown in FIGS. 6 (A) and 6 (B), and the outer surface in plan view is rectangular (rectangular) and the opposing surface 3 and A box-shaped substrate main body 2b having a back surface 4 and side surfaces 5 of four sides located between the front surface 3 and the back surface 4; a cavity 6 opening on the center side of the surface 3 of the substrate main body 2b; The metallized layer 12 and the strip-like metallized portion 16 formed in the same manner as described above are provided along the entire circumference of the surface 3 which is rectangular frame-like in plan view.
The substrate body 2b is a box-shaped body in which a rectangular frame-shaped ceramic layer c2 is integrally laminated along the periphery of the upper surface of the lower-layer ceramic layer c1 having a flat plate shape.

The cavity 6 is composed of four side surfaces 7 open to the surface 3 and a bottom surface 8 surrounded by the bottom of the side surface 7 and having a rectangular plan view. The bottom surface 8 is also substantially the mounting area 9, and a pair of (a plurality of) mounting pads are formed on the bottom surface 8.
Furthermore, on the surface 3 of the substrate body 2b, the same metallized layer 12, the recess 13, the strip-like metallized portion 16 formed along almost immediately above the recess 13, and the same bonding portion above these are formed. A metal frame 22 joined via the electrodes 18 and 19 is formed. Therefore, the metal frame 22 is firmly bonded at almost the same level above the metallized layer 12 along the opening of the cavity 6.

Therefore, as shown in FIG. 6A, an electronic component 28 such as an IC chip is mounted straddling above the pair of mounting pads 10, and the lid plate 30 is seam welded to the upper surface of the metal frame 22. Thus, the electronic component 28 can be reliably sealed from the outside.
Therefore, the effects (1) to (4) can be exhibited also by the ceramic substrate 1b.
Further, the ceramic substrate 1b can be reliably manufactured according to the above-described manufacturing method. Therefore, the manufacturing method can also exhibit the effect (5).
Also in the ceramic substrate 1b, as shown in FIG. 2B, the strip-shaped metallized portion 16 is positioned between the recess 13 on the upper surface of the metallized layer 12 and the side surface 5 side of the substrate body 2a. It may be formed on the first curved surface r1.

The present invention is not limited to the embodiments described above.
For example, the ceramic of the ceramic layer constituting the substrate body may be a high temperature fired ceramic such as mullite or aluminum nitride, or a low temperature fired ceramic such as glass-ceramic. In the latter case, copper or silver is applied to the material of the conductor such as the metallized layer 12.
Further, the cavity may be further formed on the back surface 4 side of the substrate main body 2b so as to be substantially vertically symmetrical.

Furthermore, the strip-shaped metallized portion 16 has two or more inner and outer portions at two or more positions at approximately right above the concave portions 13 and 14 of the metallized layer 11 and on the first curved surface r1 on the upper surface of the metallized layer 11. And may be formed in parallel.
The joints 18 and 19 can also be formed by groove filling welding similar to fillet welding, laser welding, or adhesion using an industrial adhesive.
In addition, the concave portions 13 and 14 may be formed on the upper surface of the metallized layer 11 so as to be parallel to each other with respect to two or more places in the inner and outer direction.

  According to the present invention, a wide metallized layer and the above-mentioned cavity side or mounting area side on the upper surface of the metallized layer are formed along the rectangular frame-like surface around the flat surface or the cavity where the flat surface of the substrate body made of ceramic is opened. Thus, it is possible to reliably provide a ceramic substrate in which strip-like metallized portions are precisely formed at required positions, and a metal frame is firmly bonded to the upper side of these, and a manufacturing method thereof.

1a, 1b ... ceramic substrate 2a, 2b ... substrate main body ..... front surface 4 ... back surface 5 ... side surface 8 ... bottom surface of cavity (mounting area)
9 ........ Mounting area 11, 12 ... Metallized layer 13, 14 ... Recess 16 ......... Band-like metalized part 18, 19 ... Brazing part 22 ......... Metal frame 24 ......... Substrate area 25 ... ......... Plan to cut c1, c2 ... ceramic layer

Claims (5)

A substrate body made of ceramic, having a rectangular outer shape in plan view and having opposed front and back surfaces, and a side surface located between the front and back surfaces;
A mounting area of the electronic component at least the center of the surface of the substrate body in a plan view;
A ceramic substrate comprising: a metallized layer having a rectangular frame shape in a plan view formed along the outer peripheral portion of the surface of the substrate main body located outside the mounting region in a plan view;
In the upper surface of the metallized layer, a recess is formed along the mounting region side more than the side surface side,
The upper surface of the metallized layer has a strip-shaped metallized portion formed along each side of the metallized layer,
In the upper surface of the metallized layer, the strip-like metallized portion at least partially overlaps the concave portion in a side view, or is formed between the concave portion and the side surface of the substrate main body.
A ceramic substrate characterized by The upper surface of the metallized layer is positioned between the upwardly convex first curved surface whose height gradually decreases from the side surface side of the substrate main body toward the concave portion, the concave portion and the mounting area, and is flat Consisting of an upwardly convex second curved surface whose width of view is narrower than the first curved surface,
The ceramic substrate according to claim 1, characterized in that: A metal frame having a rectangular frame shape in plan view is joined to the upper side of the upper surface of the metallized layer through the joint portion disposed on the mounting region side of the strip-like metallized portion and the side surface side of the substrate main body Yes,
The ceramic substrate according to claim 1 or 2, characterized in that A method of manufacturing a ceramic substrate according to any one of claims 1 to 3, wherein
In a ceramic green sheet having a plurality of substrate regions to be the substrate main body adjacent to each other vertically and horizontally in plan view, the surface to be cut across the two adjacent substrate regions is divided on the surface of each of the two substrate regions. Forming an unbaked metallized layer having a rectangular frame shape in plan view and convex upward on the outer peripheral side of the mounting region of the electronic component and along the planned cutting surface;
Forming a recess on the upper surface of the unbaked metallized layer in plan view and along the mounting area side of the planned cutting surface side of each substrate area;
Forming a non-fired strip-like metallized portion at an upper surface of the metallized layer at each position where at least a portion overlaps with the concave portion in a side view, or at every position between the concave portion and the surface to be cut; ,including,
A method of manufacturing a ceramic substrate characterized by The step of forming the concave portion is performed by pressing a pressing frame mold along the mounting area side with respect to the planned cutting surface side for each substrate area on the upper surface of the metallized layer.
A method of manufacturing a ceramic substrate according to claim 4, wherein the method comprises:

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