JP2016115795A - Ceramic wiring board and electronic component mounting package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ceramic wiring board capable of suppressing occurrence of cracking on the joint surface of a conductor layer and a through conductor, and to provide an electronic component mounting package.SOLUTION: A conductor layer 3 is embedded in a ceramic insulation layer 1 while being exposed partially, when viewing the cross section in the thickness direction. When the exposed surface of the conductor layer 3 is a first surface 3a, and the surface on the through conductor 5 side is a second surface 3b, the width w1 of the first surface 3a is larger than the width w2 of the second surface 3b. The side surface 3s of the conductor layer 3 is an inclined plane 7 from the first surface 3a across the second surface 3b, and the angle formed by the inclined plane 7 and the side surface 5s of the through conductor 5 is larger than 90°. The inclined plane 7 is a concave curved surface.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a ceramic wiring board and an electronic component mounting package.

  Conventionally, ceramic wiring boards have been widely used as wiring boards on which electronic components such as semiconductor elements and crystal resonators are mounted.

  FIG. 7A is a schematic cross-sectional view showing a conventional ceramic wiring board, and FIG. 7B is a schematic view in which the conductor layer and the through conductor of FIG. As shown in FIG. 7, the ceramic wiring board 100 is generally bonded to the ceramic insulating layer 101, the conductor layer 103 provided on the surface, and the conductor layer 103 so as to penetrate the ceramic insulating layer 101 in the thickness direction. And a through conductor 105 provided in the base.

  In recent years, with the miniaturization and high functionality of mobile terminal devices typified by mobile phones, the ceramic wiring substrate 100 has been required to be further miniaturized. For this reason, the ceramic wiring substrate 100 is formed on the surface or inside of the ceramic wiring substrate 100. Further miniaturization of the conductor layer 103 and the through conductor 105 is also being studied.

Japanese Patent Laid-Open No. 2001-15895

The ceramic wiring substrate 100 shown in FIGS. 7A and 7B has a shape in which the width changes abruptly from w ₄ to w _{5 in the} vicinity of the joint surface S between the conductor layer 103 and the through conductor 105. When such a ceramic wiring substrate 100 is viewed in a cross section in the thickness direction, a portion (surface 105s on the inner side (through conductor 105 side) of the ceramic insulating layer 101 of the conductor layer 103 is in contact with the side surface 105s of the through conductor 105 ( Hereinafter, the corner portion 106) has a structure in which the contact angle is almost a right angle and the radius of curvature R is as close to 0 as possible. For this reason, when a sudden thermal shock is applied to the ceramic wiring substrate 100 and a thermal stress is generated, stress concentration (indicated by the arrow Sc) is likely to occur at the corner portion 106 between the conductor layer 103 and the through conductor 105, There is a problem that cracks are likely to occur near the joint surface S.

  Accordingly, the present invention has been devised in view of the above problems, and the object thereof is to mount a ceramic wiring board and an electronic component capable of suppressing the occurrence of cracks at the joint surface between the conductor layer and the through conductor. Is to provide a package.

  The ceramic wiring board of the present invention includes a ceramic insulating layer, a through conductor provided so as to penetrate the ceramic insulating layer in the thickness direction, and a conductor layer bonded to the end face in the thickness direction of the through conductor; The conductor layer is embedded in the ceramic insulating layer in a partially exposed state when viewed in cross-section in the thickness direction, and the exposed surface of the conductor layer is 1 surface, when the surface on the through conductor side is the second surface, the width of the first surface is larger than the width of the second surface, and the side surface of the conductor layer is the first surface side To the second surface side, and the angle between the inclined surface and the side surface of the through conductor is greater than 90 °.

  In the electronic component mounting package of the present invention, the electronic component is disposed on the conductor layer of the ceramic wiring board.

  According to the present invention, the occurrence of cracks at the joint surface between the conductor layer and the through conductor can be suppressed.

(A) is a perspective view which shows typically 1st Embodiment of the ceramic wiring board of this invention, (b) is the sectional view on the AA line of (a), (c), It is the schematic diagram which extracted the conductor layer and through-conductor of (b). (A) is a cross-sectional schematic diagram which shows the ceramic wiring board of 2nd Embodiment, (b) is the schematic diagram which extracted the conductor layer and penetration conductor of (a). (A) is a cross-sectional schematic diagram which shows the ceramic wiring board of 3rd Embodiment, (b) is the schematic diagram which extracted the conductor layer and penetration conductor of (a). (A) is a perspective view which shows typically the ceramic wiring board of 4th Embodiment, (b) is the BB sectional drawing of (a). It is a cross-sectional schematic diagram which shows one Embodiment of the electronic component mounting package of this invention. It is a schematic diagram which shows the manufacturing process of the ceramic wiring board of 1st Embodiment. (A) is a cross-sectional schematic diagram which shows the conventional ceramic wiring board, (b) is the schematic diagram which extracted the conductor layer and penetration conductor of (a).

  FIG. 1A is a perspective view schematically showing a first embodiment of the ceramic wiring board of the present invention, FIG. 1B is a sectional view taken along line AA in FIG. FIG. 4 is a schematic view of the conductor layer and the through conductor extracted from (b).

  The ceramic wiring board of the first embodiment has a ceramic insulating layer 1 on a flat plate as a base, and a plurality of disk-like conductor layers 3 are provided on the surface 1a of the ceramic insulating layer 1 as a base so as to be spaced apart. . The ceramic insulating layer 1 has a columnar through conductor 5 provided therein so as to penetrate the ceramic insulating layer 1 in the thickness direction. The through conductor 5 is joined to the conductor layer 3 provided on the surface 1 a of the ceramic insulating layer 1 in the vicinity of the surface 1 a of the ceramic insulating layer 1.

  In this case, the conductor layer 3 is embedded in the ceramic insulating layer 1 with a part thereof exposed when the ceramic insulating layer 1 is viewed in cross section in the thickness direction.

Further, regarding the conductor layer 3, the surface (exposed surface) on the surface 1a side of the ceramic insulating layer 1 is the first surface 3a, and the surface on the inner side of the ceramic insulating layer 1 (surface on the through conductor 5) is the second surface. 3b, the width w ₁ (or diameter D ₁ ) of the first surface 3a of the conductor layer 3 is larger than the width w ₂ (diameter D ₂ ) of the second surface 3b on the through conductor 5 side.

  Further, the side surface 3s of the conductor layer 3 is a surface that is inclined with respect to the side surface 5s of the through conductor 5 from the first surface 3a side to the second surface 3b side (hereinafter may be referred to as an inclined surface 7). It has become. At this time, the angle between the side surface 3s (inclined surface 7) of the conductor layer 3 and the side surface 5a of the through conductor 5 is greater than 90 °.

  The ceramic wiring board according to the first embodiment is different from the conventional ceramic wiring board shown in FIGS. 7A and 7B in which the contact angle of the portion where the conductor layer and the side surface of the through conductor are in contact with each other is almost right. In comparison, the angle between the side surface 3s of the conductor layer 3 and the side surface 5s of the through conductor 5 is large.

According to such a configuration, even when a sudden thermal shock is applied to the ceramic wiring substrate, a thermal stress is generated, and the stress Sc is concentrated in the vicinity of the joint surface S, the concentrated stress Sc is applied to the conductor layer 3. In addition, in the inside of the through conductor 5, as shown in FIG. 1C, for example, it is dispersed in the directions of the side a ₁ , the side a _2, and the side a ₃ that form a parallelogram in a sectional view. Thus, since the stress Sc is dispersed in the vicinity of the joint surface S, generation of cracks can be suppressed.

Here, the vicinity of the bonding surface S is a region within ± 10 μm vertically from the portion where the side surface 3s (inclined surface 7) of the conductor layer 3 and the side surface 5s of the through conductor 5 intersect. In addition, the angle θ between the side surface 3s (inclined surface 7) of the conductor layer 3 and the side surface 5a of the through conductor 5 is such that the width w ₁ (diameter D ₁ ) of the first surface 3a of the conductor layer 3 is the second surface 3b. width _{w 2 (D} 2) only to have a made angle θ larger than, for example, is preferable 100 ° to 160 °.

  FIG. 2A is a schematic cross-sectional view showing the ceramic wiring board of the second embodiment, and FIG. 2B is a schematic view of the conductor layer and the through conductor in FIG. The appearance of the ceramic wiring board of the second embodiment is omitted because it is the same as the ceramic wiring board shown in FIG.

  In the ceramic wiring board of the second embodiment, as shown in FIGS. 2A and 2B, the side surface 3 s of the conductor layer 3 is connected to the through conductor 5 from the first surface 3 a side which is the surface of the conductor layer 3. It is a shape which forms a concave curved surface over the 2nd surface 3b which is the surface by the side of the joining surface S. In this case, the side surface 3s of the conductor layer 3 has a smooth curved surface over the side surface 5s of the through conductor 5.

  When the side surface 3 s of the conductor layer 3 has a concave curved surface and has a shape that forms a continuous curved surface over the side surface 5 s of the through conductor 5, it is between the side surface 3 s of the conductor layer 3 and the side surface 5 s of the through conductor 5. Unlike the ceramic wiring substrate shown in 1 (a), (b), and (c), the shape does not have an angle θ between the side surface 3s of the conductor layer 3 and the side surface 5s of the through conductor 5. As a result, stress is distributed in innumerable normal directions on the curved side surface 3s even in the vicinity of the joint surface S, so that the stress Sc in the vicinity of the joint surface S between the conductor layer 3 and the through conductor 5 can be further dispersed. As a result, the occurrence of cracks can be further suppressed.

In this case, the curvature radius R of the curved surface of the side surface 3 s of the conductor layer 3 is a concave shape in which at least the width w ₁ (diameter D ₁ ) on the first surface 3 a side of the conductor layer 3 is larger than the diameter D _{3 of the} through conductor 5. However, in the case of a ceramic wiring board of a specific example described later, for example, 5 to 30 μm, particularly 7 to It is desirable to be 25 μm.

  FIG. 3A is a schematic cross-sectional view showing the ceramic wiring board of the third embodiment, and FIG. 3B is a schematic view of the conductor layer and the through conductor in FIG. The external shape of the ceramic wiring board of the third embodiment is omitted because it is the same as the ceramic wiring board shown in FIG.

In the ceramic wiring board of the third embodiment, the side surface 5s of the through conductor 5 has a curved surface following the side surface 3s of the conductor layer 3. For example, as shown in FIGS. 3A and 3B, in the through conductor 5, the width w ₃ (diameter D ₃ ) at the central portion 5 c in the thickness direction of the ceramic wiring board is a bonding surface S with the conductor layer 3. It is larger than the end face 5b (the width w ₂ (diameter D ₂ ) of the second face 3b of the conductor layer 3). In this case, the side surface 5s from the side surface 3s of the conductor layer 3 to the central portion 5c of the through conductor 5 is a continuous curved surface.

When the side surface 3s and the side surface 5s from the conductor layer 3 to the through conductor 5 have a curved surface as described above, the range from the upper conductor layer 3 to the lower conductor layer 3 via the through conductor 5 , The boundary where the width w ₁ (diameter D ₁ ), the width w ₂ (diameter D ₂ ) of the conductor layer 3 and the width w ₃ (diameter D ₃ ) of the through conductor 5 change can be further relaxed. . As a result, not only the vicinity of the joint surface S between the conductor layer 3 and the through conductor 5 but also the stress concentration on the side of the through conductor 5 near the joint surface S can be further relaxed. This makes it possible to further suppress the occurrence of cracks.

  FIG. 4A is a perspective view schematically showing a ceramic wiring board according to the fourth embodiment, and FIG. 4B is a cross-sectional view taken along line BB in FIG. The ceramic wiring boards of the first to third embodiments can be applied to a structure in which the frame body 9 is provided on the peripheral edge portion 1b of the ceramic insulating layer 1 described above.

4A and 4B, arrows a ₄ and a ₅ indicate directions in which the ceramic insulating layer 1 and the frame body 9 thermally expand when the ceramic wiring board is heated. In this case, the arrow direction of thermal expansion faces the outside of the ceramic wiring board and a _4, represents the arrow facing the inside of the ceramic wiring board as a _5. As shown in FIG. 4 (a), when the ceramic wiring substrate is heated, the ceramic insulating layer 1 is solid including the conductor layer 3 and the through conductor 5, so that the thermal expansion is directed only to the outside. Since the frame body 9 has a space on the electronic component mounting area 1c side where the conductor layer 3 is provided, the frame body 9 also thermally expands in the direction toward the inner wall side of the frame body 9. For this reason, the direction of thermal expansion occurring in the frame body 9 is opposite to the direction of thermal expansion occurring in the ceramic insulating layer 1.

  As a result, the frame body 9 acts to restrain thermal expansion with respect to the ceramic insulating layer 1, and therefore the ceramic wiring board of the fourth embodiment shown in FIG. Compared to a flat-type ceramic wiring substrate that does not have, the thermal stress due to thermal expansion is higher in the vicinity of the junction S between the conductor layer 3 and the through conductor 5 provided in the mounting region 1c of the electronic component.

  On the other hand, in the ceramic wiring board of the fourth embodiment, the angle θ between the side surface 3s of the conductor layer 3 and the side surface 5s of the through conductor 5 is larger than 90 °. The stress Sc in can be dispersed.

  In this way, cracks are also generated in the vicinity of the joint surface S between the conductor layer 3 and the through conductor 5 even in the case of the structure having the frame body 9 on the peripheral edge 1b surrounding the electronic component mounting region 1c of the ceramic insulating layer 1. Can be suppressed.

  Here, the shellac wiring board provided with the frame body 9 has been described with reference to an example in which the frame body 9 is provided on the ceramic wiring board of the first embodiment. The same effect can be obtained with the structure in which the frame body 9 is provided on the ceramic wiring board of the third embodiment.

In the ceramic wiring boards of the first to fourth embodiments described above, it is desirable that the conductor layer 3 (first surface 3 a) is embedded so as to be flush with the surface 1 a of the ceramic insulating layer 1. When the conductor layer 3 (first surface 3a) is embedded in the surface 1a of the ceramic insulating layer 1 so as to be flush with each other, thermal deformation in the vicinity of the joint surface S between the conductor layer 3 and the through conductor 5 ( (Shrinkage and expansion) are easily constrained by the ceramic insulating layer 1, so that the difference in shrinkage due to thermal deformation between the ceramic insulating layer 1 in the vicinity of the joint surface S and the metal member which is the conductor layer 3 and the through conductor 5 ( Alternatively, the difference in expansion amount can be reduced. Thereby, generation | occurrence | production of the crack in the joint surface S vicinity can be suppressed further.

As the size of the ceramic wiring board, the area of the ceramic insulating layer 1 is 0.5 to ⁵ mm ^2.
The average thickness is 0.05 to 1 mm, the height of the frame 9 is 0.25 to 1.0 mm, the average thickness of the frame 9 is 0.05 to 0.15 mm, the ceramic insulating layer 1 and the frame The portion 9 is suitable for a wiring board constituting a small electronic component mounting package with a small thickness.

That is, the size (volume) of the outer shape of the electronic component mounting package is preferably 10 mm ³ or less, and further, a lid is provided on the upper surface of the frame body 9 so that the thermal expansion difference between the lid and the ceramic wiring board is large. In the case of a structure, it becomes more suitable.

  FIG. 5 is a schematic cross-sectional view showing an embodiment of the electronic component mounting package of the present invention. The electronic component mounting package shown in FIG. 5 (hereinafter referred to as “B”) is an example in which the ceramic wiring substrate A of the above-described fourth embodiment is applied as a ceramic wiring substrate (hereinafter referred to as “A”). is there. In this electronic component mounting package B, the electronic component 11 is mounted on the mounting surface 1 c, and the lid body 13 is bonded to the upper surface of the frame body 9.

  According to the electronic component mounting package B of the present embodiment, the generation of cracks in the vicinity of the joint surface S between the conductor layer 3 and the through conductor 5 is suppressed based on the structure of the ceramic wiring board A of the fourth embodiment. Accordingly, the electronic component mounting package B with high operational stability of the electronic component 11 can be obtained.

  The shapes of the conductor layer 3 and the through conductor 5 constituting the produced ceramic wiring board A and the electronic component mounting package B are determined from photographs obtained by observing cross sections of the ceramic wiring board A and the electronic component mounting package B.

  The ceramic insulating layer 1 and the frame body 9 are preferably made of alumina as a main component and having additives such as Si and Mg in view of high thermal conductivity and high strength. As the material of the conductor layer 3 and the through conductor 5, molybdenum (Mo), a composite metal of tungsten (W) and copper (Cu), or the like is preferable. As the lid 13, various ceramic materials and metal materials can be applied, and Kovar (Fe—Ni—Co) is a preferable material when alumina is applied to the ceramic insulating layer 1. it can.

  Next, a method for manufacturing the ceramic wiring board and the electronic component mounting package of the present embodiment will be described. FIG. 6 is a schematic view showing a manufacturing process of the ceramic wiring board according to the first embodiment.

First, a sheet-like molded body 21 for forming the ceramic insulating layer 1 is produced. The composition is, for example, a mixed powder in which Al ₂ O ₃ powder is a main component and a predetermined amount of SiO ₂ powder and MgO powder is added thereto.

  Next, an organic binder is added to the mixed powder together with a solvent to prepare a slurry or a kneaded product, which is then formed into a sheet using a molding method such as a press method, a doctor blade method, a rolling method, or an injection method. Formed body 21 is formed.

  Next, as shown in FIG. 6A, a pattern sheet 26 is formed by forming a pad pattern 23 to be the conductor layer 3 and a via pattern 25 to be the through conductor 5 on the surface of the sheet-like molded body 21. In this case, the pad pattern 23 and the via pattern 25 may be directly formed on the surface of the sheet-like molded body 21 by printing or the like. However, the pad pattern 23 and the via pattern 25 are formed on another film 27 in advance, Alternatively, a method of transferring the surface of the film 27 having the surface 23 and the via pattern 25 to the surface of the sheet-like molded body 21 may be used.

When the main component of the sheet-like molded body 21 is alumina, the conductor paste is a metal material containing molybdenum (Mo) as a main component or copper (Cu) in terms of enabling simultaneous firing. What has a composite metal with tungsten (W) as a main component is suitable.

  Next, as shown in FIG. 6B, an outer mold 29a having a recess on one surface and an inner mold 29b that fits into the recess are prepared, and using this set of molds 29a and 29b, The produced pattern sheet 26 is press-molded. In this way, a molded body 31 as shown in FIG. 6C can be manufactured.

  The shapes of the conductor layer 3 and the through conductor 5 formed on the ceramic wiring boards of the first to fourth embodiments are formed under the following conditions.

  Since the sheet-like molded body 21 needs to have high deformability in press molding described later, one having a low elastic modulus is desirable. For example, it is preferable that the storage elastic modulus at 70 ° C. is in the range of 10 to 50 MPa. The storage elastic modulus of the sheet-like molded body 21 is determined from the viscosity characteristics measured in the temperature range of 25 to 125 ° C. with a rheometer.

  The conductor pattern 23 for forming the conductor layer 3 is formed using a conductor paste having a solid content ratio of 60 to 70% by volume mainly composed of metal powder. On the other hand, the conductive pattern 25 for forming the through conductor 5 is one having a solid content ratio of metal powder as a main component and about 1/2 that of the conductive paste for the conductive pattern. The solid content ratio is preferably 30 to 40% by volume.

  Using the sheet-like molded body 21 and the conductor paste under such conditions, the conductor pattern 23 and the via pattern 25 are formed on the sheet-like molded body 21, and the compression rate (also referred to as the rolling reduction) when performing press molding is adjusted. Thus, the ceramic wiring boards of the first to fourth embodiments can be obtained. In this case, when producing a ceramic wiring board provided with the frame 9, an inner mold 29b having a convex cross section is used.

After mixing SiO ₂ powder at 5% by mass and MgO powder at 2% by mass with respect to 93% by mass of Al ₂ O ₃ powder, acrylic binder as an organic binder with respect to 100% by mass of solid content ratio. Was added to prepare a slurry. Then, the sheet-like molded object whose average thickness is 400 micrometers was produced by the doctor blade method. The storage elastic modulus at a temperature of 70 ° C. of the sheet-like molded body was 45 MPa.

  Next, as shown in FIG.6 (b), the conductor sheet and the via pattern were formed in the obtained sheet-like molded object, and the pattern sheet was produced. A conductor paste having a solid content ratio of 65% by volume was used for forming the conductor pattern, and a conductor paste having a solid content ratio of 35% by volume was used for forming the via pattern.

  Next, using a metal mold, press molding was performed at a temperature of 80 ° C., thereby producing a mother molded body having a conductor pattern and a via pattern. Next, the mother molded body was cut into a predetermined size, and molded bodies having structures shown in FIGS. 1, 2, 3 and 4 were produced.

  The reduction ratio when the press molding was performed was determined as the thickness (average thickness) of the pattern sheet central portion after press molding with respect to the thickness (average thickness) of the pattern sheet central portion before press molding.

  Next, these molded bodies were fired for 1 hour in a reducing atmosphere under conditions where the maximum temperature was 1400 ° C. The surface of the conductor layer of the ceramic wiring board obtained by firing was subjected to nickel and gold plating in this order. In the ceramic wiring board having the structure of FIGS. 1, 2, 3 and 4, the surface of the conductor layer and the surface of the ceramic insulating layer are flush with each other.

  The obtained ceramic wiring board had a plane area of 2 mm × 2 mm and a ceramic insulating layer thickness (average thickness) of 0.1 mm. In addition, the average thickness of the frame body of the ceramic wiring board shown in FIG. 4 was 0.15 mm, and the height from the mounting surface of the frame body was 0.5 mm.

  Next, a crystal oscillation element was mounted as an electronic component on the mounting region of the obtained ceramic wiring board, and a lid was joined via a brazing material (silver brazing) to produce an electronic component mounting package.

  Next, a thermal shock test was performed by immersing the produced electronic component mounting substrate in a solder bath heated to 300 ° C. for about 1 second. The crack was confirmed using a sample obtained by polishing a cross section of a ceramic wiring board. The number of samples was 100 each.

  Regarding the shape of the conductor layer and the through conductor constituting the fabricated ceramic wiring board, when the conductor layer is viewed in cross section in the thickness direction, a part of the conductor layer is exposed and embedded in the ceramic insulating layer, and the conductor layer is exposed. When the first surface is the first surface and the surface on the through conductor side is the second surface, the width of the first surface is larger than the width of the second surface. The state where the surface is inclined toward the two surfaces and the state where the angle between the inclined surface and the side surface of the through conductor is greater than 90 ° were determined from photographs obtained by observing the cross section of the ceramic wiring board.

At this time, the width w ₂ (diameter) of the conductor layer near the joint surface between the conductor layer and the through conductor, the width w ₃ (diameter) of the central portion of the through conductor, the side surface of the conductor layer near the joint surface and the through conductor The angle with the side surface and the radius of curvature from the side surface of the conductor layer to the side surface of the through conductor were calculated.

  The produced samples (Sample Nos. 2 to 7) were buried in the ceramic insulating layer with the conductor layer exposed. Moreover, in these samples, the width of the first surface was larger than the width of the second surface. Sample No. 2 and Sample No. 7 had a shape in which the side surface of the conductor layer formed an inclined surface from the first surface side to the second surface side. Sample No. In the ceramic wiring boards of 3 to 6, the inclined surface of the conductor layer had a concave curved surface. Among these, sample No. In 5 and 6, the side surface of the through conductor was curved from the center to the conductor layer side.

  As a comparative example, a ceramic wiring board having the structure shown in FIG. 7 was prepared by a conventional method, and the same evaluation was performed. The conventional method is a manufacturing method in which a through hole is formed in a sheet-like molded body, a conductive paste is filled in the through hole, and then a conductive pattern is formed on the surface.

  As is apparent from Table 1, in the ceramic wiring board (sample Nos. 2 to 7) having the structure shown in FIGS. 1 to 4, the crack generation rate was 11% or less.

  2 and 3 (samples Nos. 3, 4, 5, and 6) having a larger rolling reduction than the samples (samples No. 2 and 7) having the structure of FIG. The curvature radius of the side surface from the conductor layer to the through conductor gradually decreased, and the crack generation rate was reduced.

  In contrast, the sample having the structure of FIG. 7 (sample No. 1) had a crack generation rate of 49%.

A ... Ceramic wiring board B ... Electronic component mounting package 101 ... Ceramic insulating layer 1a ... .... Surface 3, (ceramic insulating layer) 3, 103 ... Conductor layer 3s ... (Conductor layer) side face 5, 105 ... Penetration conductor 5s ... side face 5c (through conductor) ... center part (through conductor) 7 ... inclined Surface 9 ··········································································· lids w ₁ , w ₂ ... Width (of conductor layer) w ₃ ..... Width of (through conductor)

D ₁ , D ₂ ... (Diameter of conductor layer) D ₃ ... (Diameter of through conductor) S. Sc ··· Stress 21 ·········· Sheets 23, 25 ······ Conductor pattern 26 ··· Pattern sheet 27 ... film 29a ... outer mold 29b ... inner mold 31 ...・ Molded body

Claims (6)

  A ceramic wiring board comprising: a ceramic insulating layer; a through conductor provided so as to penetrate the ceramic insulating layer in the thickness direction; and a conductor layer bonded to the end face in the thickness direction of the through conductor. The conductor layer is embedded in the ceramic insulating layer in a partially exposed state when viewed in cross-section in the thickness direction, and the exposed surface of the conductor layer is formed on the first surface and the through conductor side. When the surface is the second surface, the width of the first surface is larger than the width of the second surface, and the side surface of the conductor layer is inclined from the first surface side to the second surface side. A ceramic wiring board, wherein the angle between the inclined surface and the side surface of the through conductor is greater than 90 °.   The ceramic wiring board according to claim 1, wherein the inclined surface of the conductor layer has a concave curved surface.   When the through conductor is viewed in cross section in the thickness direction, the width of the central portion in the thickness direction is larger than the width of the first surface of the conductor layer, and the side surface of the through conductor extends from the central portion to the conductor layer side. The ceramic wiring board according to claim 1, wherein the ceramic wiring board has a curved surface.   The said 1st surface of the said conductor layer is embed | buried in the said ceramic insulating layer so that it may become the same surface as the surface of the said ceramic insulating layer, The Claim 1 thru | or 3 characterized by the above-mentioned. Ceramic wiring board.   The ceramic wiring board according to claim 1, wherein a frame body is provided along a peripheral edge portion of the ceramic insulating layer.   6. An electronic component mounting package, wherein an electronic component is disposed on the conductor layer of the ceramic wiring substrate according to claim 1.