JP4744110B2 - Ceramic member, method for manufacturing the same, and electronic component using the same - Google Patents

Description

  The present invention relates to a method for forming a recess in a ceramic member, and more particularly, to a recess for dividing a ceramic substrate and a recess for mounting a semiconductor chip used in an electronic component.

  The concave portion formed in the ceramic member is formed for use in dividing, and for mounting a circuit such as a semiconductor chip, particularly in a ceramic substrate for electronic components.

  A general method for forming these recesses is to form a recess by pressing a blade provided in a mold on a sheet-like ceramic green sheet. Recently, there is a problem that the shrinkage of the product is large and the dimensional accuracy is inferior, and in recent years when high dimensional accuracy is required, there are an increasing number of methods for thermally processing a sintered ceramic member such as a laser.

The method of forming a recess by irradiating a sintered ceramic member with laser light is to melt the workpiece with the thermal energy of the laser light and process it into a desired shape. , ceramic melted may remain on the front surface of the recess, also problem melt the optical system of the recess of the rim or laser apparatus is flying wear has occurred.

Therefore, as a method of preventing the molten layer from remaining in the recesses formed by the laser processing, the assist gas or a gas different from the assist gas is sprayed on the surface to be processed at the same time as the laser beam irradiation (hereinafter not shown), how does leaving a molten layer on the concave table surface by sucking ceramic vapor sublimated by laser light is disclosed (Patent Document 1).

  Although there are many prior arts by the above method, none of the methods can satisfactorily remove the molten layer. Therefore, as described below, a number of prior arts have been disclosed regarding a method of removing a molten layer remaining in a recess processed with a laser beam.

  As one of the methods, there is a chemical etching method (not shown below). In this example, a through-hole is formed. However, the through-hole is formed in an alumina substrate with a laser beam and then immersed in a phosphoric acid solution to melt the through-hole. It is disclosed that the inner wall surface is roughened by etching the layer (Patent Document 2).

  As another method, there is a method of removing the molten layer by sandblasting (hereinafter not shown). In this case as well, a through hole is formed, but spherical glass beads are blown into the through hole processed with laser light. It is disclosed that the melted layer of the through hole can be removed without roughening the surface of the ceramic substrate (Patent Document 3).

Further, as a method having a different processing mechanism, as shown in FIG. 16, a ceramic member 101 is irradiated with a laser beam 121 oscillated by a CO ₂ laser through a condenser lens 122, and a temperature of 600 ° C. or less is applied to the irradiated surface. A method of cutting the ceramic member 101 by generating a crack 119 due to thermal stress is disclosed (Patent Document 4). Unlike the method described above, this method causes little thermal damage to the workpiece and does not generate a molten layer.

  As with the remaining of the molten layer on the concave surface, a major problem in laser processing is the landing of the melt around the processing site. Melting of the melt is a major problem regardless of whether the melt occurs on the workpiece or the optical system of the laser apparatus.

  As a method for solving the above-described problem, in Patent Document 1 described above (not shown), while irradiating a workpiece with laser light, a gas different from the assist gas is used as a waste material from the side that becomes the product of the workpiece. The welded material is prevented from adhering to the product side of the workpiece by spraying the sublimated vapor of the ceramic as the workpiece with the suction nozzle.

However, not only can the welded material not be completely prevented by the above-described method, but the processing with laser light is not limited to the case where there is always a waste material on one side. For this reason, it is also disclosed that a part other than the laser light irradiation part (hereinafter not shown) is patterned with a protective layer such as a resin film to prevent the welded material from adhering to the workpiece (Patent Document 5).
Japanese Patent Application Laid-Open No. 8-141764 JP-A-1-112794 Japanese Patent Laid-Open No. 2004-22643 JP 2000-323441 A JP-A-3-252384

However, the method in which gas is blown to the laser processing site described in Patent Document 1 to suck the vapor sublimated from the workpiece with a nozzle is difficult to completely suck even in cutting or hole processing. if more concave shape, it was not possible to eliminate the residual melt layer to recess table surface. As shown in FIG. 17, when the recess 102 is formed as the dividing groove 103 in the ceramic member 101, the molten layer 116 remains with respect to the processing depth d <b> 2 of the recess 102 as shown in FIG. 17. The substantially concave portion 102 has a depth d1. Therefore, if the depth of the concave portion 102 is shallow, dividing the ceramic member 101 along the concave portion 102 may result in poor division of the ceramic member 101 or in order to avoid poor division. When 102 is formed deeply, problems such as cracking or cracking before the dividing step occur frequently.

Furthermore, since the melted layer 116 of the recess 102 is formed by heating the ceramic with laser light and then cooling and solidifying it, innumerable microcracks 117 are generated due to shrinkage during cooling. As shown in FIG. 18, there is an electronic component 105 that forms an end face electrode 107 so as to be connected to the circuit pattern 106 after forming the circuit pattern 106 on the main surface of the ceramic member 101 and dividing it along the recess 102. If there is a microcrack 117 in the melted layer 116 on the surface of the divided recess 102, the melted layer 116 and the ceramic member 101 are likely to be peeled off by the microcrack 117, thereby reducing the adhesion strength of the end face electrode 107, and melting. low anchor effect for the front surface of the layer 116 is a smooth surface, the adhesion strength between the ceramic member 101 including an end electrode 107 melt layer 116 has a problem of a decrease.

  In order to solve these problems, Patent Document 2 discloses a method of removing the molten layer 116 by chemical etching. However, since the ceramic member 101 itself is immersed in an etching solution, it is necessary to protect a portion that is not to be roughened with a resist film. There is a problem that even if patterning is performed with a resist film, the etching solution does not roughen in the vicinity of the boundary of the resist film and the surface becomes rough, and the ceramic member 101 has, for example, a lattice-like delicate and numerous recesses 102. There is a problem that this method cannot be adopted in the formed one.

  Further, in the method of forcibly removing the molten layer 116 by sandblasting in Patent Document 3, not only the molten layer 116 is removed but also the surface of the alumina substrate is ground, so that the substrate surface must be smooth. The ceramic member 101 was not a suitable method.

  Moreover, since the method of patent documents 1-3 mentioned above melts and sublimates the ceramic member 101 which is a to-be-processed object with a laser beam, as shown in FIG. 19, the ceramic of the periphery of the processed recessed part 102 is shown. It has been unavoidable that a ceramic weld 118 is attached to the member 101 and the condenser lens 122. Such contamination by the welded material 118 of the optical system reduces the laser processing capability, and the adhesion of the welded material 118 to the surface of the ceramic member 101 is a cause of poor formation of the circuit pattern 106 or damage to the mask for forming the circuit pattern. There was a problem of becoming.

  Here, the welded material 118 attached to the surface of the workpiece is generally removed by buffing or the like on the surface of the ceramic member 101. The process of removing the welded material 118 is a basic process after laser processing. The current situation is that it is a process. However, when the welded material 118 is removed by a physical process such as buffing, particle destruction occurs on the ceramic surface of the workpiece, and when this is used for the electronic component 105 to form the circuit pattern 106, the adhesion of the pattern is avoided. There was a problem that the strength decreased.

  On the other hand, Patent Document 4 is not based on the high-energy heat irradiation processing inherent to the laser, but is performed by running the crack 119 by a thermal stress of low-temperature heat irradiation at which the ceramic does not melt. However, in this method, as shown in the cross-sectional view of the recess 102 formed in the ceramic member 101 of FIGS. 20A, 20B, and 20C, a substantially V-shaped or U-shaped dividing groove of the recess 102 is provided. Processing of a desired shape and depth such as 103 and the semiconductor chip mounting recess 104 was impossible.

Further, in the laser processing including the above-described conventional process for removing the molten layer 116, the main component ceramic and a small amount of various additives existing in the non-processed part are melted, and the generated molten layer 116 is removed. and for which the composition of the front surface of the recess after laser processing is substantially identical to the composition having the ceramic member other than the recess, in which various additives are substantially uniformly dispersed in the ceramic main component there were.

  However, in the electronic component 105 in which the end face electrode 107 is formed in the ceramic member dividing recess 102, the adhesion between the conductive material constituting the end face electrode 107 and the main component ceramic constituting the ceramic member 101 is inferior in recent years. With the miniaturization of the electronic component 105 to be obtained, the contact area between the ceramic member 101 and the end face electrode 107 has been reduced, and the problem of adhesion has been exposed.

  Furthermore, in the conventional laser processing, as shown in the plan view of FIG. 21A, even if the dividing groove 103 closer to the continuous groove is formed, the wide portion D1 of the dividing groove 103 and the narrow width are narrowed. There is a portion D2, and the difference between the widths D1 and D2 is inevitable at least 10 μm or more. This is a reduction in the dimensional accuracy of the shape processing as it is, and after dividing along the dividing groove 103, the side surfaces are uneven, so that the ceramic members or jigs and the like are connected to the side surfaces. There is a problem that chipping of the ceramic member 101 is liable to occur when contact is made. Then, as shown in the cross-sectional view of FIG. 21 (b), the dividing groove 103 also has an up and down wave shape in the depth direction. For example, when the maximum depth d3 is processed to 100 μm or more, a shallow portion d4 and The difference d5 is inevitable at least 20 μm or more, and the problem of occurrence of poor division or cracks or cracks could not be solved.

Furthermore, although illustrated ceramic member 101 having a semiconductor chip mounting recess 104 in FIG. 22, and a flat bottom surface 104a of the recess 102, the ceramic fused layer forms a nonexistent recess 102 laser processing However, the manufacturing method of such a recess 102 is a method of laminating and firing ceramic green sheets with and without through holes, and forming recesses by sandblasting on the sintered substrate. However, all of these methods have a problem of high cost.

  In order to solve the above-mentioned problems comprehensively, the present inventor has found an innovative and highly reliable ceramic member and its processing technology after trial and error.

The ceramic member of the present invention is a ceramic member comprising a recess formed by laser light on at least one main surface, and the ceramic member contains 92.0 to 99.9% by mass of Al ₂ O _{3. SiO} 2, MgO, together comprising a CaO as agent, characterized in that Si is present in 50-80% of the area of the surface of the recess.

Further, the surface of the concave portion is formed by a grain interface of the Al ₂ O ₃ crystal grains.

  Furthermore, the variation in the distance between the boundary lines between the concave portion and the main surface of the ceramic member is 4 μm or less.

Furthermore, the depth variation of the concave portion is 8 μm or less.

Furthermore, the ceramic member is a plate-like body , and the concave portion is a groove for dividing the ceramic member.

The electronic component of the present invention is the is the circuit pattern on a main surface having the concave portion of the ceramic member is formed, and the conductor so as to connect the recess with the circuit pattern is formed, the ceramic along the recess An electrode is formed on an end face obtained by dividing the member.

The electronic component of the present invention using the ceramic member, at least one layer of the thin-film metal layer is provided in the recess of the ceramic member, at least one layer of the metal plating layer is formed on the thin film metal layer, the wherein the semiconductor chip is mounted on the metal plating layer.

The method for producing a ceramic member of the present invention is obtained by firing a ceramic containing Al ₂ O ₃ 92.0 to 99.9% by mass and containing SiO ₂ , MgO and CaO as additives into a plate shape. at least one main surface of the sintered body to form a recess by laser light, Si is a method for producing a ceramic member that exist in 50-80% of the area of the surface of said recess to form said recess in the Al ₂ O ₃ less than the melting point of the site, and, in Rukoto pointing irradiation with laser light at a temperature above the melting point of said SiO _2, and forming the recess.

Further, the laser light is a CO ₂ laser.

According to the ceramic member of the present invention, at least one main surface is a ceramic member provided with a recess formed by laser light , and the ceramic member is Al ₂ O ₃ 92.0 to 99.9% by mass. , _SiO 2, MgO as an additive, with comprising the CaO, the Rukoto exists Si is 50 to 80% of the area of the surface of the recess, a conductor such as edge electrode by thick film paste to the recess When formed, the additive that forms the vitreous contained in the paste moves to the portion of the ceramic member on the surface where the Si does not exist, while the Si constituting the ceramic member moves to the paste. By doing so, the mutual diffusion of the conductor to the ceramic member is improved.

As described above, according to the method for producing a ceramic member of the present invention, since the recess is formed by irradiating the laser beam at a temperature lower than the melting point of Al ₂ O ₃ and higher than the melting point of the SiO ₂ , without weld deposits of scattered to the periphery, not even occur fouling optical science system.

  Hereinafter, embodiments of the ceramic member of the present invention will be described.

  FIG. 1 is a perspective view showing an example of a ceramic member 1 according to the present invention. FIG. 1 (a) shows a recess 2 formed as a dividing groove 3, and FIG. 1 (b) shows a recess 2 for mounting a semiconductor chip. What was formed as 4 is shown. The recess 2 may be provided on both main surfaces 1a and 1a 'of the ceramic member 1.

The ceramic member 1 of the present invention contains 92.0 to 99.9% by mass of Al ₂ O ₃ and contains SiO ₂ , MgO, and CaO as additives, and is formed on at least one main surface by irradiation with laser light. The surface 2a of the recess 2 has a component (silica) having a melting point lower than that of the ceramic (alumina) as the main component in 50 to 80% of the area of the surface 2a of the recess 2 I am letting. FIG. 3A shows an EPMA analysis (Electron Probe Micro) of the surface 2a of the recess 2 of the ceramic member 1 processed by the heat irradiation.
FIG. 3 (b) shows a drawing substitute photograph of EPMA analysis of the non-thermally irradiated part. Here, as an embodiment of the present invention, the ceramic constituting the main component of the ceramic member 1 is alumina, and calcia, magnesia, and silica as an additive having a lower melting point than ceramic are used as additives. In each of the EPMA analysis methods, the analysis site was vapor-deposited with gold, the analysis area was set to 67 μm in both length and width, the mapping conditions were K spectral line, and the distribution state of Si element was analyzed with spectral crystal TAP. Here, the black portions in the photographs of FIGS. 3A and 3B represent portions where Si is not present in the above method.

That is, as shown in FIG. 3 (b), Si , which is an additive having a melting point lower than that of alumina, is dispersed throughout the non-heat-irradiated part, but as shown in FIG. It can be seen that the Si is unevenly distributed in the portion 2a.

As described above, since Si is unevenly distributed on the surface 2a of the recess 2 without being uniformly dispersed, when a conductor such as an end face electrode is formed in the recess 2 with a thick film paste, the additive contained in the paste Part of the ceramic member 1 moves to a portion of the ceramic member 1 where Si does not exist, while the additive Si having a lower melting point than the main component ceramic constituting the ceramic member 1 moves to the paste and thereby interdiffuses. There is an effect that the adhesion strength of the conductor to the ceramic member 1 is improved.

Further, the ceramic member 1 of the present invention is that exists in the area of the surface 2a lower melting point than Al ₂ O ₃ of the Si is 50 to 80 percent of the recess 2. This is because, as shown in FIG. 4, in the small electronic component in which the concave portion 2 formed in the ceramic member 1 is divided and the end face electrode 7 is formed on the side surface 1 b including the concave portion 2 and connected to the circuit pattern 6. The adhesion strength between the side surface 1b and the end surface electrode 7 can be increased. For example, an electronic component of the so-called “0402” type has a length of 0.4 mm, a width of 0.2 mm, a thickness of 0.1 mm, and an end face electrode 7 formed on a side surface having a width of 0.2 mm. If the melted layer 116 and the microcrack 117 are present in 2a, the adhesion strength of the end face electrode 7 will be greatly reduced. Further, even if the molten layer 116 is removed by the above-described method, the adhesion strength cannot be satisfied because the electrode formation area is small, but as described above, it is included in the paste for forming the end face electrode 7. Ceramic member 1 and end face electrode in which Si of SiO ₂ lower than the melting point of Al ₂ O ₃ is uniformly dispersed by a part of the additive and Si in ceramic member 1 moving and interdiffusion with each other Therefore, the adhesion strength between the ceramic member 1 and the terminal electrode 7 can be improved more easily. Then, the SiO ₂ Si having a melting point lower than that of Al ₂ O ₃ is unevenly distributed on the surface 2 a of the recess 2, so that the adhesion strength is improved by 80% or less compared to the case where the Si 2 is not unevenly distributed. This is under the condition that Si of SiO _{2 having} a melting point lower than that of Al ₂ O ₃ exists in the area 2a.

Here, when an additive having a melting point lower than that of the ceramic as the main component occupies an area exceeding 80% of the surface 2a of the concave portion 2, it is difficult to improve the adhesion strength of the conductor. When the value is less than 50%, melting of Al ₂ O ₃ occurs in part, and the features of the present invention are impaired. A more preferable range of the proportion of SiO ₂ Si having a melting point lower than that of Al ₂ O _{3 in} the area of the surface 2a of the recess 2 is 50% or more and 70% or less.

The surface 2a of the recess 2, as shown in the schematic diagram of FIG. 5 (a), is preferably made of a grain boundary of the crystal grains 13 of _Al 2 _{O 3.} FIG. 5B shows a schematic diagram of the surface 102a of the conventional laser-processed recess 102. The surface 102a is a molten glassy material 14 and the molten glassy material 14 is solidified immediately after laser processing. It is covered with microcracks 117 due to the shrinkage of. When a conductor is formed on the surface 102a, the adhesion strength is reduced in both thick and thin conductor formation. In order to solve this problem, when the molten layer 116 is removed by a physical method, as shown in FIG. 5C, the molten layer 116 does not exist, but the ceramic crystal grains 13 below it are destroyed. Therefore, the surface 102a of the recess 102 becomes an intragranular fracture surface.

However, when a conductor is formed on the intragranular fracture surface with a thick film or a thin film, the surface of the particle is a smooth surface, so the anchor effect is low and the adhesion strength of the conductor may be reduced. In contrast, the front surface 2a of the recess 2 of the ceramic member 1 of the present invention, the crystal grains 13 of the ceramic is grain boundary, and, in order to melt layer 116 does not cover the surface, the thick film, thin film either Even when the conductor is formed by the anchor, the anchor effect is large, and therefore, a high adhesion strength of the conductor can be obtained.

Moreover, as shown in FIG. 6, it is preferable that the dispersion | variation in the distance D between the recessed lines 2 and the main surface 1a of the ceramic member 1 is 4 micrometers or less. Conventionally, when a concave portion having a depth of 100 μm or more is formed in a ceramic member, it must be processed by a powerful CO ₂ laser. In this case, at least the variation in the distance D between the boundary lines is 50 μm or more. There was a problem of becoming. And when this recessed part is used as a dividing groove, there are at least 25 μm or more unevenness on the side surface after the division, and when the side surface of the ceramic member 1 and the jig or the like come into contact, the ceramic member 1 is likely to be chipped, It may be difficult to form a conductor on the side surface, and sufficient adhesion strength may not be obtained.

  On the other hand, when the variation in the distance D between the boundary lines is 4 μm or less, the unevenness on the side surface after the division can be reduced to 2 μm or less even when the concave portion 2 is used as the dividing groove 3. Even if it comes in contact with a jig or the like, it is possible to prevent the ceramic member 1 from being chipped, and to suppress poor printing of conductor formation. Furthermore, high dimensional accuracy can be ensured even if the fine lattice-shaped dividing grooves 3 as shown in FIG. 7 are formed.

  Here, the variation in the distance D between the boundary lines is that if the length of the concave portion 2 is 1 mm or more in the laser processing distance, the laser light dots are included in about 10 dots in the conventional laser. Since the variation is not greatly different from the case of the investigation, the maximum value D1 and the minimum value D2 of the distance D between the boundary lines of the opposing main surface of the recess 2 at a predetermined length of 1 mm or more are measured, and the difference is measured between the boundary lines. It is assumed that the distance D varies. The measurement method may be a factory microscope for conventional laser processed products, but the measurement of the present invention may be within the measurement error range of the factory microscope due to small variations. Gold for surface analysis was vapor-deposited on the main surface side including the concave portion 2 of the member 1, and a SEM analysis photograph was taken to measure the distance on the photograph. In addition, although the substantially linear recessed part 2 is shown in Fig.6 (a), you may form the meandering recessed part 2 like FIG.6 (b).

  Further, as shown in FIG. 8, the variation d5 in the depth d of the recess 2 is preferably 8 μm or less. Conventionally, even when the concave portion 2 having a depth of 100 μm or more is formed in the ceramic member so as to be a continuous groove for division, the concave portion 2 becomes a triangular wave groove and the variation d5 is at least 30 μm or more. Is difficult to form, and if the depth d of 20% or more of the thickness t of the ceramic member 1 is not processed, defective division is likely to occur.

  On the other hand, since the variation d5 of the depth d is as small as 8 μm or less, when the recess 2 is used as a dividing groove, if the thickness t of the ceramic member 1 is 15% or more and 20% or less, there is a problem in the dividing property. In addition, since it is not necessary to increase the depth d more than necessary, it is possible to prevent the occurrence of cracks and cracks in the handling and heat treatment steps before the dividing step.

  Here, the variation d5 of the depth d of the recess 2 is a laser processed product, as in the variation of the distance D between the boundary lines, and a highly accurate value can be obtained by confirming a length of 1 mm or more. . The difference between the maximum depth d3 and the minimum depth d4 of the concave portion 2 at the predetermined distance is the variation d5 of the depth d. Generally, after applying the red flaw detection liquid to the concave portion 2, it is divided along the concave portion 2 and is divided by a factory microscope. The depth of the colored portion is measured. In the product of the present invention, since the variation d5 of the depth d is small, the measurement with a factory microscope may fall within the measurement error range. Therefore, after dividing along the recess 2, gold for surface analysis was deposited on the divided side surface to take a SEM analysis photograph, and the variation d5 of the depth d was obtained from the photograph.

Further, the ceramic member 1 of the present invention, _Al 2 _O 3 92.0~99.9 wt% in the main component, _SiO 2, MgO as an additive, that contain and CaO. Here, the range of Al ₂ O ₃ can secure the necessary characteristics as a ceramic member for electronic parts, and the above additives are desirable as a binder. The surface 2a of the concave portion 2 of the ceramic member 1 of the present invention has a grain boundary crystal plane because the main component of alumina is not melted, and SiO ₂ Si having a melting point lower than that of alumina is uniform on the surface 2a. There is a region where the Si exists and a region where the Si does not exist, and Si is unevenly distributed (distributed) on the surface 2a. Therefore, when a conductor made of a thick film, a thin film, or the like is formed on the surface 2a of the recess 2, the above-described interdiffusion action between the additive in the ceramic member 1 and the additive in the conductor is caused by the grain boundary crystal plane. The adhesion strength of the conductor can be improved by a high anchor effect.

  Here, as the ceramic constituting the main component of the present invention, aluminum nitride, silicon nitride, ferrite, or alumina zirconia-based ceramics may be used in addition to the alumina.

Further, the ceramic member 1 of the present invention is a the ceramic member 1 is a plate-like body, since the recess 2 is a groove for dividing the ceramic member 1, the division of a large number of fine to the plate-like body of the first sheet Even if the groove 3 is formed, its dimensional accuracy is high. Furthermore, since the variation in the depth d of the recess 2 is small, even if the depth d is shallow, the splitting property is good and the generation of cracks and cracks can be prevented.

As shown in FIG. 4, the electronic component 5 of the present invention is obtained by dividing the concave portion 2 of the ceramic member 1 formed as a groove to be divided along the concave portion 2 as shown in FIG.
A circuit pattern 6 is formed on the main surface a of the substrate, and a conductor is formed so as to connect the circuit pattern 6 and the recess 2, and the electrode 7 is formed on the end surface 1 b obtained by dividing the ceramic member 1 along the recess 2. Is formed. The electrode 7 is usually formed by dipping a thick film paste on a ceramic member and firing it, but there is no molten layer on the surface 2a of the recess 2, and the crystal grains of the main component ceramic are grain boundary crystal planes. In addition, since SiO ₂ Si having a melting point lower than that of Al ₂ O ₃ is unevenly distributed, the thick film paste can easily enter the ceramic member 1 and constitute a glassy material contained in the thick film paste. Part of the additive to be added and Si of SiO _{2 having} a melting point lower than that of Al ₂ O ₃ in the ceramic member 1 move to each other, so that the adhesion strength of the conductor can be improved by the high anchor effect and the mutual diffusion action of the additive. .

Moreover, as shown in FIG. 2, the electronic component 5 of the present invention is provided with at least one thin film metal layer 8 in the recess 2 of the ceramic member 1 using the ceramic member 1 of the present invention described above. That is, at least one metal plating layer 9 is formed on the thin metal layer 8, and the semiconductor chip 10 is mounted on the metal plating layer 9. No melt layer 116 on the front surface 4a of the semiconductor chip mounting recess 4, the crystal grains of _Al 2 _{O 3} is a grain boundary, and which is localized the Al ₂ O ₃ of less SiO ₂ than the melting point of Si from the case of forming the thin metal layer 8 by vapor deposition on the front surface 4a of the semiconductor chip mounting recess 4, it can form a coherent high strength thin metal layer 8 by interdiffusion effect of the additive with high anchoring effect. Accordingly, when the metal layer 9 is formed thereon by plating or the like and the semiconductor chip 10 is mounted, the electronic component 5 having high adhesion strength and high reliability can be obtained.

  Below, the manufacturing method of the ceramic member 1 of this invention is demonstrated.

As shown in FIG. 10, a method of manufacturing a ceramic member 1 in which a recess 2 is formed on at least one main surface 1 a of a ceramic member 1 by heat irradiation 20 with a laser beam , where the recess 2 is formed. In this manufacturing method, the concave portion 2 is formed by performing heat irradiation 20 at a temperature lower than the melting point of Al ₂ O ₃ of the ceramic member 1 and higher than the melting point of the SiO ₂ .

  More specifically, when the main component ceramic is alumina and the additive is silica, magnesia or calcia, the melting point of alumina is about 2050 ° C., the melting point of silica is about 1730 ° C., and the melting point of magnesia is about 2800 ° C. , Calcia has a melting point of about 2570 ° C. In the conventional laser processing, since it is processed by heat irradiation at about 3500 ° C., all of the main component alumina, the additive silica, magnesia, and calcia melt, and partly sublimates, so that the melt is formed. The molten material is scattered around to form a welded material, and the melted material is cooled and solidified in the processed portion to form a molten layer, and microcracks are generated in the molten layer by the cooling.

However, according to the method for producing a ceramic member of the present invention, heat irradiation 20 that is lower than the melting point of ceramic (alumina) as a main component and that is lower than the melting point of alumina among the above additives is higher than the melting point of silica. to irradiate the machined portion of the ceramic member 1, since the melting of the alumina is not Hey cause, because the melting layer and weld deposits described above is not formed, it is possible to suppress the occurrence of microcracks, the recess having a desired shape 2 Can be formed.

FIG. 11A shows a cross-sectional shape after processing the recess 2 processed by the method of the present invention, and the recess 2 is closed by the altered layer 18. The generation mechanism of the deteriorated layer 18 is that the Si moves only in the portion where the heat irradiation 20 is applied by the heat irradiation at a temperature higher than the melting point of SiO ₂ constituting the vitreous without melting Al ₂ O _3. A part of the sublimation results in the formation of an altered layer 18 having a weak adhesion. That is, the distribution of the additive component having a melting point higher than the melting point of the ceramic among the additives constituting Al ₂ O ₃ and the glassy material is not changed from that before the heat irradiation, but the alteration layer 18 is in the entire ceramic member 1. The SiO ₂ Si having a melting point lower than that of the additive component ceramic constituting the glassy material, which was uniformly distributed, was moved by the above-described heat irradiation, and the distribution was uneven in the ceramic member 1. Therefore, the composition is different from that of the molten layer 116 and is also defined as a deteriorated layer because it is different from the matrix of the ceramic member 1 before heat irradiation.

  Since the portion of the above-mentioned deteriorated layer 18 is exposed to the heat irradiation 20 at a high speed, the unheated portion and a clear boundary line are formed by the cracks 19, so that the deteriorated layer 18 is loosely clogged in the recess 2. It has become. Therefore, the altered layer 18 can be easily removed by a physical method such as ultrasonic vibration, and FIG. 11B shows a layer obtained by removing the altered layer 18 from the recess 2.

  Further, the moving speed s of the heat irradiation is preferably 10 m / min or more. This utilizes the characteristics of ceramics that are inferior in thermal conductivity. By moving the heat irradiation part at high speed, a crack 19 is generated due to the difference in thermal stress between the heat irradiation part and the other part. If the speed s is less than 10 m / min, it is difficult to form a crack accurately. When the heat irradiation is performed by the laser beam 21, the processing start generally enters from the dummy part and proceeds to the processing of the product part, but the width of the dummy part is large and the processing table moving speed s is a predetermined speed. Therefore, when the allowance is taken into consideration, a more preferable value of the moving speed is 13 m / min or more. Here, the upper limit value of the moving speed s is actually limited by the capability (moving speed, accuracy) of the processing table. In the manufacturing method of the present invention, the desired recess 2 is formed even at 100 m / min. It has been confirmed that it can be formed.

Also, Ru using laser light 21 as heat used for heat radiation 20 of a method of manufacturing the ceramic member 1 of the present invention. The heat irradiation 20 by the laser beam 21 can be performed with high dimensional accuracy, and therefore the recess 2 having a desired shape can be formed.

The laser light 21 is preferably a CO ₂ laser. This is because the heat irradiation 20 is performed with the laser beam 21 by the CO ₂ laser, so that even a thick ceramic member 1 can be processed with a stable depth at a high speed.

  Next, the manufacturing method which produces the recessed part of the ceramic member 1 of this invention with a laser beam is demonstrated in detail.

  A pulse waveform 24 generally used for ceramic processing is shown in FIG. Since ceramic processing requires high energy, a pulse waveform 24 that rises quickly after laser oscillation has been used. Specifically, after laser oscillation, 20 to 60 μsec. Thus, a desired shape is processed by melting and sublimating the ceramic at a temperature of about 3500 ° C., reaching the maximum temperature range 24a. Therefore, at this time, a problem peculiar to laser processing that a ceramic melt layer and a welded product are generated has occurred. On the other hand, the method of the present invention uses a slow rising laser waveform 24 as shown in FIG. 12B. Specifically, the time until the maximum temperature 24a is reached after the laser oscillation is 90%. ~ 200 μsec. It is said.

  Further, as shown in the ON-OFF signal diagram of FIG. 13A, one pulse of the oscillation signal 25 of the normal laser is set to 200 μsec. Compared to the above, the manufacturing method according to the present invention has a total oscillation time of about 60 μsec. For one pulse of the normal signal 25, for example, the ON signal 26 is two short pulses. And about 30% of the normal laser oscillation signal 25. By oscillating the pulse waveform 24 having a slow rise as described above with a short ON signal 26, the pulse waveform 24 having a slow rise within the short ON signal 26 is oscillated as shown in the schematic diagram of FIG. Heat irradiation with the maximum temperature 24a controlled can be performed. That is, it can be set to process at a temperature lower than the melting point a of the main component ceramic and higher than one or more melting points b of the additive components. In addition, the pulse period is 200 μsec. A pulse waveform approximating CW (Continuity Wave) continuous oscillation is obtained by the following, and the recess 2 processed by this is the boundary of the recess 2 when viewed in plan as described above with reference to FIGS. It is possible to perform processing while suppressing variations in distance D between lines and variations in depth d.

  The ceramic member of the present invention was prepared by the following method.

(Example 1) 96% by mass of Al ₂ O ₃ alumina and ceramics as the main component, and the balance consisting of additives and impurities. As additives, 2.0% by mass of SiO ₂ and 0.2% by mass of CaO. %, MgO is added at 1.0% by mass to form a ceramic green sheet, and the ceramic green sheet is cut into a predetermined shape and fired at a temperature of about 1600 ° C. to obtain a ceramic sintered body having a thickness of 0.635 mm. Produced.

  Next, as shown in FIG. 14 (a), a continuous dividing groove 3 having a processed width D of the recess 2 of 30 μm and a depth d of 100 μm is formed on the main surface 1′a of the ceramic sintered body 1 ′. did. The recess 2 was formed with a radius of curvature R at the tip of 5 μm.

Conditions of thermal irradiation, using a slowly rising pulse waveform 24 as shown in FIG. 12 (b) by a CO ₂ laser oscillator, as shown in FIG. 13, 30 .mu.sec time ON signal 26. And the pulse period is 100 μsec. (Frequency: 10 kHz) The moving speed s of the laser beam 21 was 13 m / min. The number of samples is 5 sheets and sample numbers 1-5. Here, the temperature of heat irradiation in the embodiment of the present invention is about 1850 ° C. on the surface irradiated with the laser beam 21.

  As a comparative example, the ceramic sintered body 1 ′ uses the same member as that of the present invention described above, the dividing groove 103 having a machining width D of the recess 102 of 90 μm, a depth d of 100 μm, and a tip curvature radius R of 5 μm. Was made. Here, the depth d and the radius of curvature R of the tip indicate the processing depth with the laser beam 21 and indicate the processing depth d including the molten layer 116 deposited in the concave portions 2 and 102 after processing.

Heat irradiation conditions at this time, with rising early pulse waveform 24 as shown in FIG. 12 (a) by a CO ₂ laser oscillator, as shown in FIG. 13, 400 .mu.sec time ON signal 26. And the pulse period is 1050 μsec. The recess 102 was processed at a frequency of 952 Hz and a moving speed s of the laser light 21 of 8 m / min. The number of samples is 5 sheets and sample numbers 6-10. Here, the temperature on the irradiation surface of the laser beam 21 of the comparative example is about 3400 ° C.

Longitudinal length H of the recess 2,102 worked in the above-described condition is confirmed front surface 2a of 12 mm, the presence or absence of melting layer 116 102a visually. Next, similarly, the SEM analysis is performed on the difference between the maximum value and the minimum value of the width D when the length H of the recesses 2 and 102 is 12 mm, that is, the variation in the distance between the boundary lines of the main surfaces 1a and 101a and the recesses 2 and 102. (Scanning electron microscope analysis) was performed and calculated from SEM photographs. In addition, the depth d of the recesses 2 and 102 is divided along the recesses 2 and 102, and then the fracture surface is vapor-deposited and an SEM analysis photograph is taken. When the length H of the recesses 1 and 102 is 12 mm, the maximum The difference between the depth and the minimum depth was calculated from the above photograph and used as the variation in depth d.

Further, the bending load of the concave portions 2 and 102 is set such that the span L is 28 mm around the concave portions 2 and 102 in the ceramic members 1 and 101 before the division of the SEM analysis as shown in FIG. A pressing load P was applied from the back side of Nos. 2 and 102, and the bending load when divided was measured. The width H of the sample was 12 mm and the pressing speed was 5 mm / min. The above measurement results are shown in Table 1.

As can be seen from Table 1, in Sample No. 6-10 is a comparative example, the front surface 102a of the recess 102 there is melted layer 116, Although not shown in Table, the periphery of the recess 102 since the weld deposits 118 was adhered and fused layer 116 and weld deposits 118 is cooled after laser machining, micro-cracks occurred on the periphery of the front surface 102a and the concave portion 102.

For these, Sample No. 1-5 of the present invention embodiment, the molten layer 116 does not exist on the front surface 2a of the recess 2, also, although not shown in Table, the periphery of the recess 2 since there was no adhesion of weld deposit 118 could be microcracks form a nonexistent recess 2.

Further, the variation in the width D of the recesses 2 and 102, that is, the variation in the distance between the boundary lines, the average value of the sample numbers 6 to 10 in the comparative example was 52 μm, and the variation in the depth was 35 μm, both of which were large values. On the other hand, the average value of the boundary line variation of sample numbers 1 to 5 of the embodiment of the present invention was 2.4 μm, and the average value of the depth variation was 5.8 μm. irregularities less surface state of the surface of the second front surface 2a is good, and there was no occurrence of burr due defect division since variation in depth is small.

  Further, the bending load of the concave portions 2 and 102 is 6.4 N in the average value of the sample numbers 6 to 10 in the comparative example and the variation thereof is large, but the average value of the sample numbers 1 to 5 in the embodiment of the present invention is 5 Since the value is as low as 0.0 N and the variation is small, the splitting property in the recess 2 is improved.

  From these, the ceramic member 1 of the present invention has no adhesion of the melted layer 116 or the welded material 118, which has been regarded as a drawback of the conventional laser processing, and can form the concave portion 2 with high precision dimensional position accuracy, The depth d is also suitable as the dividing groove 3 or the semiconductor chip mounting recess 4 because it can be manufactured with less variation that cannot be obtained by conventional laser processing.

  (Example 2) Next, using the ceramic member 1 described above, a sample in which the moving speed s of the heat irradiation was changed was prepared, and the generation of the molten layer 116 and the welded material 118 was confirmed.

The processing conditions of the ceramic member 1 of the present invention were the same as in Example 1 except that the main surface 1′a of the ceramic sintered body 1 ′ was continuously divided with a processing width D of the recess 2 of 30 μm and a depth d of 100 μm. For the groove 3, a pulse waveform 24 having a slow rise as shown in FIG. 12B is generated by CO ₂ laser oscillation, and the time of the ON signal 26 is set to 30 μsec. And the pulse period is 100 μsec. Irradiation was performed at a frequency of 10 kHz, and the moving speed s of the laser beam 21 was 8, 9, 10, 13, 20 m / min, and the sample numbers were 11 to 15, respectively.

  Here, the temperature on the irradiation surface of the laser beam 21 is about 2100 to 2200 ° C. for sample numbers 11 and 12, while it is about 1770 to 1950 ° C. for sample numbers 13 to 15.

Then, the presence / absence of the melted layer 116 in the recess 2 of the processed ceramic member 1 and the presence / absence of the adhesion of the welded material 118 to the peripheral edge of the recess 2 were visually confirmed. The results are shown in Table 2.

  As can be seen from Table 2, in Sample No. 11 where the moving speed s of the laser beam 21 is 8 m / min, the melted layer 116 exists in the recess 2, and the welded material 118 adheres to the periphery of the recess 2. It was. Sample No. 12 having a moving speed s of 9 m / min had the melted layer 116 in the concave portion 2, but the welded material 118 did not adhere to the periphery of the concave portion 2. In Sample Nos. 13 to 15 having the moving speed s of 10 m / min or more, there was no existence of the melted layer 116 in the concave portion 2 and adhesion of the welded material 118 to the peripheral edge of the concave portion 2.

  If the moving speed s of the heat irradiation is made slower than this, the rise as described above is slow, and even with the method of processing with the pulse waveform 24 that is cut in the middle of the rise, the melting of the ceramic as the main component starts. It can be seen that a deposit is generated. Therefore, the preferable moving speed s of heat irradiation is 10 m / min or more, and more preferably 13 m / min or more in consideration of the error range.

  Example 3 Using the same ceramic sintered bodies 1 'and 101' as used in Example 1, the recesses 2 and 102 were formed under the following conditions.

  In the ceramic member 1 of the present invention, the moving speed of the laser beam 21 passes through the continuous dividing groove 3 having a processing width D of 30 μm and a depth d of 100 μm on the main surface 1a ′ of the ceramic sintered body 1 ′. Recesses 2 were produced at s of 13 m / min.

The conditions of the heat irradiation were such that the pulse waveform 24 with a slow rise of CO ₂ laser oscillation as shown in FIG. 12B was used, and the sample number 16 was set to 38 μsec. And the pulse period is 125 μsec. (Frequency 8000 Hz) Sample No. 17 has a time of 33 μsec. And the pulse period is 111 μsec. (Frequency 9000 Hz) Sample No. 18 has a time of 30 μsec. And the pulse period is 100 μsec. (Frequency: 10 kHz) Sample No. 19 sets the time of the ON signal 26 to 25 μsec. And the pulse period is 87 μsec. (Frequency 11.5 kHz) Sample No. 20 has the above ON signal 26 time of 23 μsec. And the pulse period is 77 μsec. Processing was performed at a frequency of 13 kHz. Here, as for the temperature on the irradiation surface of the laser beam 21, the sample number 16 is about 2030 ° C, while the sample numbers 17 to 20 are about 1770 ° C to 1950 ° C.

Further, as a comparative example, using the same ceramic sintered body 1 ′, a dividing groove 103 having a processing width D of the recess 102 of 90 μm and a depth d of 100 μm is formed on the main surface of the ceramic sintered body 1 ′. The moving speed s of the laser beam 21 was 8 m / min. The heat irradiation conditions at this time were as follows: a pulse waveform 24 having a fast rise as shown in FIG. 12A by CO ₂ laser oscillation, and the ON signal 26 time being 400 μsec. And the pulse period is 1050 μsec. Sample No. 21 was processed at a frequency of 952 Hz and the temperature on the irradiated surface was about 3400 ° C.

Then, the front surface 2a of the recess 2,102 formed on each sample, by performing the EPMA analysis of 102a, confirming the dispersion state of the additive and its proportion.
Here the front surface 2a of the recess 2 and 102, with respect to the area of 102a, defined as localized a case where silica is present in the area of 95% or less. In addition, the ratio of the area of the silica which exists in the surface and cross section of the ceramic member 1 which does not add heat irradiation etc. is about 97 to 99% in a certain arbitrarily defined area.

  Next, the variation in the distance between the boundary lines with the main surfaces 1a and 101a and the variation in the depth over the width 12 mm of the recesses 2 and 102 were measured in the same manner as in Example 1.

Then, after the division along the recess 2,102, as shown in FIG. 15, the front surface 2a of the divided recesses 2,102, to form an electrode 17 for testing 102a. The paste of the electrode 17 was applied using a commercially available copper electrode paste so as to have a film thickness of 50 μm, and baked at 850 ° C. in a nitrogen reduction furnace. The paste contains silica as an additive.

Then, an aluminum cylinder having a diameter of 1 mm was adhered to the surface of the electrode 17 with a resin adhesive, and the peel strength between the electrode 17 and the ceramic members 1 and 101 was measured by pulling in a direction perpendicular to the surface of the electrode 17. . The pulling speed was 1 mm / min. The above results are shown in Table 3.

As can be seen from Table 3, Si is uniformly dispersed on the surface 102a of the recess 102 of the sample number 21, which is a comparative example, and the dispersion corresponds to 99% of the area of the surface 102a. Sample No. 16 had a Si distribution ratio of 90%, and the degree of uneven distribution was small. As a result, in Sample No. 21, the effect of mutual diffusion between Si and Si in the electrode 17 was small, so that the peel strength of the electrode with respect to the ceramic member 1 was low, and the adhesion strength between the ceramic member 1 and the electrode 17 was remarkably high. Declined.

On the other hand, in the sample numbers 17 to 20 of the examples of the present invention, the Si was unevenly distributed on the surface 102a, and the distribution ratio occupied 50 to 80% in the area of the surface 102a. Thus, by the Si in the Si and the electrode 17 are mutually diffused and the adhesion strength between the ceramic member 1 and the electrode 17 is improved, peeling strength of the electrode 17 is increased.

  On the other hand, Sample No. 16 had a large variation in the distance between the boundary lines of 4.3 μm and the depth variation of 8.4 μm, so that printing failure occurred at the time of electrode formation, and the peel strength of the electrode slightly increased.

  However, the variation in the distance between the boundary lines of sample numbers 17 to 20 was 4.0 μm or less, and the depth variation was 8.0 μm or less. The strength was further improved.

In addition, electrodes were formed in the recesses 2 and 102, and the test results of the peel strength were 30 MPa for the sample number 21 of the comparative example and 39 MPa for the sample number 16; It can be seen that when the surface is 45 to 54 MPa and Si is unevenly distributed on the surface of the recess, for example, if the end face electrode is formed after the recess is divided, the adhesion strength of the electrode can be improved. Although not in the embodiment, when the concave portion of the ceramic member of the present invention is used as a concave portion for mounting a semiconductor chip, there is no molten layer on the surface of the concave portion, and no welded material is attached to the periphery thereof. When a thin metal layer is deposited, a high anchor effect can be obtained, and there is no possibility that a delicate circuit pattern on the periphery is disconnected by the welded material.

(A), (b) is a perspective view which shows an example of the ceramic member of this invention. It is sectional drawing which shows an example of the electronic component of this invention. (A) the recess table surface of the ceramic member of the present invention, (b) is a photograph substituted for drawing of each EPMA analysis results of the non-thermal radiation unit. It is sectional drawing at the time of using the ceramic member of this invention as an electronic component. (A), (b), (c) is a schematic view of the crystal grains of the recess table surface. It is a top view of the ceramic member of this invention. It is a top view which shows an example of the ceramic member of this invention. It is a recessed part division | segmentation fracture surface of the ceramic member of this invention. It is a fragmentary sectional view of the electronic component of this invention. It is a perspective view which shows an example of the manufacturing method of the ceramic member of this invention. (A), (b) is recessed part sectional drawing of the ceramic member of this invention. (A), (b) is a schematic diagram of a pulse waveform. (A) is a schematic diagram of ON-OFF of a pulse signal, (b) is a schematic diagram which shows the relationship between the rise of a pulse waveform, and temperature. (A) is a perspective view of a ceramic member, (b) is sectional drawing of a bending load measurement. Is a perspective view of an electrode was formed on the concave table surface. It is a perspective view which shows an example of the conventional laser processing method. It is a perspective view of the conventional ceramic member. It is a fragmentary sectional view of the electronic component which used the conventional ceramic member. It is sectional drawing of the conventional laser processing. (A), (b), (c) is sectional drawing which shows an example of the ceramic member which has a recessed part. The conventional ceramic member is shown, (a) is a top view, (b) is sectional drawing. The perspective view of the conventional ceramic member is shown.

Explanation of symbols

1,101: ceramic members 2,102: recess 2a, 102a: front side <br/> 3, 103: dividing grooves 4,104: semiconductor chip mounting recess 5,105: Electronic parts 6,106: circuit pattern 7 107: End face electrode 8: Thin metal layer 9: Metal layer 10: Semiconductor chip 11: Conductor 13: Crystal particle 14: Glassy 15: Additive 16: Ceramic substrate 17: Electrode 18: Altered layer 19: Crack 20: Thermal irradiation 21: Laser light 22: Condensing lens 23: Processing table 24: Pulse waveform 25: Normal laser oscillation signal 26: ON signal 116: Molten layer 117: Micro crack 118: Welded material 119: Crack

Claims (9)

A ceramic member provided with a recess formed by laser light on at least one main surface, the ceramic member comprising 92.0 to 99.9% by mass of Al ₂ O ₃ , SiO ₂ , MgO as additives , together comprising the CaO, ceramic members characterized that you present Si is 50 to 80% of the area of the surface of the recess. Surface of the recess, ceramic member according to claim 1, characterized in that it consists of grain boundary of the Al ₂ O ₃ crystal grains. 3. The ceramic member according to claim 1, wherein a variation in a distance between boundary lines between the concave portion and the main surface of the ceramic member is 4 μm or less.   The ceramic member according to any one of claims 1 to 3, wherein a variation in the depth of the recess is 8 µm or less. The ceramic member according to any one of claims 1 to 4 , wherein the ceramic member is a plate-like body, and the concave portion is a groove for dividing the ceramic member. A circuit pattern is formed on a main surface having the recess of the ceramic member according to claim 5 , and a conductor is formed so as to connect the circuit pattern and the recess, and the ceramic member is divided along the recess. An electronic component having an electrode formed on an end face. Using the ceramic member according to any one of claims 1 to 5 , at least one thin film metal layer is provided in the concave portion of the ceramic member, and at least one metal plating layer is formed on the thin film metal layer. An electronic component comprising a semiconductor chip mounted on the metal plating layer. A ceramic containing Al ₂ O ₃ 92.0 to 99.9% by mass and containing SiO ₂ , MgO, and CaO as additives is fired into a plate shape, and is formed on at least one main surface of the obtained ceramic sintered body. forming a recess by laser light, Si is a method for producing a ceramic member that exist in 50-80% of the area of the surface of said recess, said less than the melting point of Al ₂ O ₃ at a site to form the recess in, and, said laser beam at a higher temperature than SiO ₂ having a melting point of irradiation shines in Rukoto, method for producing a ceramic member characterized by forming the recess. Method for producing a ceramic member according to claim 8, wherein the laser beam is a CO ₂ laser.

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