JP5294828B2 - Laminated board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated substrate which can effectively suppress occurrence of defects such as delamination or cracks of a ceramic insulating layer. <P>SOLUTION: The laminated substrate 9 is formed as follows: an insulating substrate 2 is formed by lamination of three or more ceramic insulating layers 1; grounding conductor layers or power supply conductor layers 3 are formed in a vertically overlapping manner on two or more consecutive interlayer portions of the ceramic insulating layers 1; a penetrating conductor 4 is formed to be electrically insulated from the grounding or power supply conductor layers 3, while penetrating the portions of the ceramic insulating layers 1 where the grounding or power supply conductor layers 3 are formed in the thickness direction therebetween, and land patterns 5 are formed to be connected with the penetrating conductor 4 vertically, with outer edges of the land patterns 5 being not overlapped along the vertical direction of the penetrating conductor 4. Since the outer edges of the land patterns 5 are not overlapped in the vertical direction, a good contact can be obtained between the ceramic insulating layers 1, and due to dispersion of stress, cracks in the ceramic insulating layers 1 can be effectively suppressed. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a laminated substrate in which three or more ceramic insulating layers are laminated, and in particular, surrounds a through-conductor that penetrates the ceramic insulating layer in the thickness direction, a land pattern connected vertically, and the land pattern. The present invention relates to a multilayer substrate in which a ground conductor layer or a power supply conductor layer electrically insulated from a through conductor is formed between two or more successive layers of a ceramic insulating layer.

  Insulating substrate in which a plurality of ceramic insulating layers made of a ceramic material such as a glass ceramic sintered body or an aluminum oxide sintered body are laminated as a laminated substrate on which electronic components such as semiconductor elements, capacitive elements, and piezoelectric vibrators are mounted And conductors such as through conductors, ground conductors, power supply conductors, and wiring conductors formed on an insulating base are widely used.

  The insulating substrate has, for example, a flat plate shape (cuboid shape), and has a mounting portion for mounting electronic components on the upper surface and the lower surface. For example, a wiring conductor is formed on the mounting portion, and an electronic component is electrically connected to the wiring conductor. The wiring conductor is formed in a circuit pattern on the mounting portion and the inside of the insulating base, and on the surface (lower surface, etc.) opposite to the mounting portion, and becomes a part of a conductive path that electrically connects the electronic component to the external electric circuit. .

  The through conductor is formed so as to penetrate the ceramic insulating layer in the thickness direction, and functions as a conductive path that conducts the inside of the insulating base body vertically. For example, a through conductor is connected to a wiring conductor formed in the mounting portion, and a portion located on the lower surface or inside of the insulating base is electrically connected to the wiring conductor of the mounting portion through the through conductor.

  Note that land patterns connected to the through conductors in the vertical direction are formed between the ceramic insulating layers. The land pattern is formed in, for example, a circular shape, and makes the electrical connection between the through conductors formed in the upper and lower ceramic insulating layers more reliable.

  In addition, a ground conductor and a power supply conductor are formed in layers between the ceramic insulating layers for electromagnetic shielding of the mounted electronic component, ground potential and power supply to the electronic component, and the like.

Such a multilayer substrate forms a through-hole serving as a through conductor in a ceramic green sheet obtained by forming raw powders such as ceramic powder and glass powder into a sheet shape together with an organic solvent and a binder, and then the surface of the ceramic green sheet In addition, a metal paste is applied or filled in the through-holes, three or more ceramic green sheets are laminated, and the laminate is fired.
JP 2007-324557 A

  However, in such a laminated substrate, in order to ensure the above-described electromagnetic shielding, ground potential, power supply, etc., a ground conductor layer or a power conductor layer is continuously provided between two or more layers. In some cases, a land pattern may be formed by being surrounded by the ground conductor layer or power supply conductor layer. In such a case, adhesion failure (delamination) between layers of the ceramic insulating layer or cracks in the ceramic insulating layer may occur. There has been a problem that defects such as these are likely to occur.

  This is because, in the vicinity of the outer edge of the land pattern surrounded by the ground conductor layer or the power supply conductor layer, the upper and lower ceramic insulation layers (ceramics to be ceramic insulation layers) are divided by the thickness of the land pattern and the thickness of the ground conductor layer or the power supply conductor layer. This is because the adhesion of the green sheet is likely to be hindered.

  Also, if the outer edges of the land pattern connected to the top and bottom of the penetrating conductor overlap vertically, there is a difference in shrinkage during firing between the ceramic insulating layer (ceramic green sheet) and the land pattern (metal paste) at such an outer edge. Stresses such as stress are easily generated, and the stresses are superposed on each other, so that cracks are likely to occur.

  In particular, since there is a need for grounding without fluctuation and stable power supply in recent years as the frequency increases, there are cases in which, for example, six or more ground conductor layers and power conductor layers are formed between a plurality of ceramic insulating layers. In such a case, the above-described problems are prominent because many of the portions that tend to cause the above-described poor adhesion and cracks continue in the upper and lower layers.

  The present invention has been completed in view of the above-mentioned problems of the prior art, and the object thereof is to connect with a through conductor continuously between two or more layers of a ceramic insulating layer forming an insulating base. To provide a multilayer substrate capable of effectively suppressing the occurrence of defects such as delamination and cracks in a ceramic insulating layer even when a land pattern and a ground conductor layer surrounding the land pattern are formed. is there.

In the multilayer substrate of the present invention, an insulating base is formed by laminating three or more ceramic insulating layers, and a ground conductor layer or a power conductor layer is vertically disposed on two or more successive layers of the ceramic insulating layers. And a through conductor penetrating in a thickness direction through a portion of the ceramic insulating layer between the ground conductor layer or the power conductor layer where the ground conductor layer or the power conductor layer is not formed. A land pattern is formed that is electrically insulated from the conductor layer or the power supply conductor layer and connected to the top and bottom of the through conductor, and the outer edges of the land pattern do not overlap the top and bottom of the through conductor , In the ground conductor layer or the power supply conductor layer, the inner edge surrounding the land pattern does not overlap the upper and lower sides of the through conductor, and is not between the same layers of the ceramic insulating layer. Te, the size of the land pattern connected to the respective adjacent said through conductor is to different from each other.

According to the multilayer substrate of the present invention, three or more ceramic insulating layers are laminated to form an insulating base, and a ground conductor layer or a power conductor layer is provided on two or more continuous layers of the ceramic insulating layers. A through conductor that is formed so as to overlap vertically and penetrates the portion of the ceramic insulating layer between the ground conductor layer or the power conductor layer where the ground conductor layer or the power conductor layer is not formed in the thickness direction is a ground conductor layer or Since the land pattern is formed to be electrically insulated from the power supply conductor layer and connected to the through conductors in the upper and lower directions, the outer edges of the land pattern do not overlap the upper and lower sides of the through conductors. Since the part (outer edge of the land pattern) that hinders the adhesion between the ceramic insulation layers is dispersed between the two layers, the upper and lower ceramic insulation layers are adhered well. Rukoto can. In addition, since the stress acting between the land pattern and the ceramic insulating layer does not overlap at the position where the upper and lower layers act, the occurrence of cracks in the ceramic insulating layer can be suppressed.

  Therefore, according to the multilayer substrate of the present invention, the land pattern connected to the through conductor in succession between two or more layers of the ceramic insulating layer forming the insulating base, and the ground conductor layer or the power supply conductor surrounding the land pattern Even if the layer is formed, it is possible to provide a multilayer substrate capable of effectively suppressing the occurrence of defects such as delamination and cracks in the ceramic insulating layer.

  In the multilayer substrate of the present invention, in the above configuration, the ground conductor layer or the power supply conductor layer is formed between the upper and lower ceramic insulating layers between the upper and lower ceramic insulating layers when the inner edges surrounding the land pattern do not overlap the upper and lower sides of the through conductor. The position of the inner edge surrounding the land pattern surrounding the land pattern and the ground pattern of the power supply conductor layer that is easy to interfere with the adhesion between the insulating layers or to be affected by stress such as stress caused by the difference in shrinkage during firing Distributed. Therefore, the upper and lower ceramic insulating layers can be more closely adhered, and the occurrence of cracks in the ceramic insulating layer can be more effectively suppressed.

  Further, in the above-described configuration, the laminated substrate of the present invention has the same structure between the adjacent through conductors when the size of the land pattern connected to each of the adjacent through conductors is different between the same layers of the ceramic insulating layer. The width of the ground conductor layer and the power supply conductor layer can be suppressed from being partially narrowed.

  That is, some of the land patterns connected to the same through conductor are larger than others in order to prevent the outer edges of the land patterns from overlapping above and below the through conductor when viewed in plan. For this reason, if large land patterns are adjacent to each other in the same layer, the width of the ground conductor layer and the power supply conductor layer between the through conductors may be narrowed, resulting in an increase in electrical resistance and unstable ground and power supply potentials. There is sex. On the other hand, as described above, if the sizes of the land patterns connected to each of the adjacent through conductors are different from each other in the same layer of the ceramic insulating layer, large land patterns are adjacent to each other in the same layer. Since it is easy to prevent matching, it is possible to suppress the width of the ground conductor layer and the power supply conductor layer from being narrowed, and to stabilize the potential of the ground and the power supply.

  The multilayer substrate of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing an example of an embodiment of a laminated substrate of the present invention. In FIG. 1, 1 is a ceramic insulating layer, 2 is an insulating substrate formed by laminating three or more ceramic insulating layers 1, 3 is a ground conductor layer or power supply conductor layer, 4 is a through conductor, and 5 is a land pattern. The laminated substrate 9 is basically constituted by the ceramic insulating layer 1 (insulating base 2), the ground conductor layer or power source conductor layer 3, the through conductor 4, and the land pattern 5. For example, an electronic component (not shown) is mounted on the top surface of the multilayer substrate 9 and the electronic component is electrically connected to an external electric circuit through the through conductor 4 and the land pattern 5. Used as a substrate.

  The ceramic insulating layer 1 is made of a ceramic sintered body such as a glass ceramic sintered body, an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, a silicon nitride sintered body, or a silicon carbide sintered body. Made of material.

  Three or more ceramic insulating layers 1 are laminated to form an insulating substrate 2. Since the insulating base 2 needs to form the ground conductor layer or the power source conductor layer 3 between the ceramic insulating layers 1 so that two or more of the insulating bases 2 continuously overlap each other as described later, three or more ceramic layers are required. The insulating layer 1 is formed by being laminated.

  For example, if each ceramic insulating layer 1 is made of a glass ceramic sintered body, the insulating base 2 has a suitable organic binder and solvent for the raw material powder made of glass powder such as glass and ceramic powder such as aluminum oxide. Add and mix to make a mud-like shape, and then apply a doctor blade method to make it into a sheet shape to obtain a plurality of ceramic green sheets. Then, the ceramic green sheets are cut and punched appropriately. A plurality of the laminated green sheets are formed, and finally, the laminated ceramic green sheets are fired at a temperature of about 900 to 1000 ° C. in a reducing atmosphere.

  The insulating base 2 functions as a base for mounting electronic components such as semiconductor elements, capacitive elements, and piezoelectric vibrators, and for incorporating electronic component elements such as filter circuit elements and amplifier circuit elements therein. For example, it has a mounting portion 2a on which an electronic component is mounted on the upper surface, the lower surface, or the like (upper surface in the example of FIG. 1).

  In the example of this embodiment, a wiring conductor 6 is formed on the insulating base 2. A portion of the wiring conductor 6 formed on the mounting portion 2a on the upper surface of the insulating base 2 is for electrically connecting an electronic component (not shown) mounted on the mounting portion 2a. The formed part is for electrical connection with an external electric circuit (not shown).

  The ground conductor layer or the power supply conductor layer 3 is for supplying, for example, a ground potential or a power source to an electronic component mounted on the mounting portion 2a, or electromagnetically shielding the electronic component from the outside. In addition, an electronic component element (not shown) built in the insulating base 2 may be electromagnetically shielded. The electronic component element built in the insulating base 2 is formed of a conductive layer such as an inductor or a capacitor that is formed between the ceramic insulating layers 1 and constitutes a filter circuit.

  For this purpose, that is, in order to sufficiently stabilize the potential of the ground and the power supply or to ensure the electromagnetic shielding, the ground or power supply conductor layer 3 is provided between the ceramic insulating layers 1. Each of the two or more continuous objects is formed so as to overlap each other.

  Such a ground conductor layer or power supply conductor layer 3 is formed in a wide area, for example, covering almost the entire surface between layers of the ceramic insulating layer 1 in order to stabilize the supply of the ground potential and the power supply to the electronic components.

In this case, for example, the ground conductor layer or the power supply conductor layer 3 surrounds the land pattern 5 in order to avoid an electrical short circuit with a through conductor 4 and a land pattern 5, which will be described later, which are conductive paths for transmitting signals of electronic components. It is formed with. Further, when the wiring conductor 6 is formed inside the insulating substrate 2, when a part of the wiring conductor 6 passes through a portion where the ground conductor layer or the power supply conductor layer 3 is not formed, The power supply conductor 3 and the wiring conductor 6 are also electrically insulated.

  The through conductor 4 is formed so as to penetrate the ceramic insulating layer 1 in the thickness direction, and functions as a conductive path that conducts the inside of the insulating base 2 up and down.

  In the example of this embodiment, the through conductor 4 that penetrates the ceramic insulating layer 1 on the upper side of the insulating base 2 is connected to the wiring conductor 6 formed in the mounting portion 2a, and the wiring conductor 6 is insulated. It is electrically connected to a wiring conductor (not shown) formed inside the base 2.

  Further, the through conductor 4 that penetrates the ceramic insulating layer 1 on the lower side of the insulating base 2 is connected to, for example, a wiring conductor (not shown) formed inside the insulating base 2 and insulated from the wiring conductor. The wiring conductor 6 on the lower surface of the base 2 is electrically connected.

  In the example shown in FIG. 1, the through conductor 4 is formed between the upper surface and the lower surface of the insulating base 2 and the inside of the insulating base 2. 2 may be formed so as to be electrically connected to each other between the wiring conductors formed inside.

  In addition, land patterns 5 connected to the through conductors 4 are formed between the ceramic insulating layers 1. The land pattern 5 is for ensuring the electrical connection between the upper and lower through conductors 4. That is, for example, when the thin through conductors 4 having a diameter of about 75 μm are directly connected to each other, the upper and lower through conductors 4 are electrically connected to each other through a relatively wide land pattern 5. Since a slight misalignment is allowed, the connection is easy and reliable.

  The land pattern 5 is formed so as to be surrounded by the ground conductor layer or the power supply conductor layer 3 at a certain distance, and is electrically insulated from the ground conductor layer or the power supply conductor layer 3.

  The through conductors 4 and the land patterns 5 are conductive paths that vertically conduct the interior of the insulating base 2 as described above. For example, electronic components mounted on the mounting portion 2a are connected to the lower surface and side surfaces of the insulating base 2 and the like. It is formed to lead out electrically to the outer surface.

  The ground conductor layer or power supply conductor layer 3, the through conductor 4, and the land pattern 5 are formed of a metal material such as copper, silver, palladium, gold, tungsten, molybdenum, or manganese. Further, these metal materials are formed on the ceramic insulating layer 1 in the form of a metallized conductor which is fired integrally with the insulating base 2, for example.

  If the ground conductor layer or the power supply conductor layer 3, the through conductor 4 and the land pattern 5 are made of, for example, copper, a metal paste of copper is molded on the surface of the ceramic green sheet to be the insulating base 2 and the ceramic green sheet in advance. It is formed by printing, filling and filling the through-holes formed by processing means such as processing and co-firing with the ceramic green sheet.

  In the multilayer substrate 9, the land pattern 5 does not overlap the upper and lower sides of the through conductor 4. Since the outer edge of the land pattern 5 does not overlap the upper and lower sides of the through conductor 4 in this way, a portion that hinders the close contact between the ceramic insulating layers 1 between the upper and lower ceramic insulating layers 1 (the outer edge of the land pattern 5). Can be dispersed and the upper and lower ceramic insulating layers 1 can be satisfactorily adhered.

  Therefore, according to this multilayer substrate 9, the land pattern 5 connected to the through conductor 4 and the ground conductor surrounding the land pattern 5 continuously between two or more layers of the ceramic insulating layer 1 forming the insulating base 2. Even if the layer or the power supply conductor layer 3 is formed, the multilayer substrate 9 capable of effectively suppressing the occurrence of defects such as poor adhesion between the upper and lower ceramic insulating layers 1 and cracks in the ceramic insulating layer 1 is provided. Can be provided.

  The ceramic insulating layer 1 is formed with a thickness of about 50 to 300 μm, for example, when it is made of a glass ceramic sintered body, and is composed of a ground conductor layer or power source conductor layer 3, a land pattern 5, and a wiring conductor 6. Etc. are formed with a thickness of about 10 to 25 μm.

  The number of laminated ceramic insulating layers 1 is appropriately set according to the type and number of electronic components to be mounted, the number of terminals, and the like. For example, in the case of the multilayer substrate 9 on which a semiconductor element (IC or the like) and a capacitor element (chip capacitor or the like) are mounted, the total thickness (thickness of the insulating substrate 2) is 300 to 1500 μm with about 3 to 15 layers. The layers are stacked in such a number that the degree is reached.

  In the case of such a laminated substrate 9, the distance between the inner edge surrounding the land pattern 5 of the ground conductor layer or the power supply conductor layer 3 and the outer edge of the land pattern 5 may be set to about 50 to 150 μm. Further, the distance between the outer edges of the land patterns 5 between the upper and lower ceramic insulating layers 1 may be about 50 to 300 μm.

  In addition, the land pattern 5 is connected to the through conductor 4 in the vertical direction, but has an effect of suppressing problems such as poor adhesion between the upper and lower ceramic insulating layers 1 and cracks in the ceramic insulating layer 1 if the outer edges do not overlap each other. . Therefore, even when the land pattern 5 is connected to the through conductor 4 in the upper and lower directions in the ceramic insulating layer 1 having two or more layers (three or more are continuous in the vertical direction), the land pattern 5 has different external dimensions and shapes. There are two types, and these may be arranged alternately on the top and bottom.

  Further, as long as the land pattern 5 satisfies the condition that the top and bottom connected to the through conductor 4 do not overlap vertically, three or more types having different external dimensions and shapes are randomly arranged vertically. It may be what you have. The land patterns 5 may all have different external dimensions and shapes.

  When the land pattern 5 is formed under these conditions, the upper and lower sides of a certain through conductor 4, the outer edge of the land pattern 5 connected to the through conductor 4 and the upper and lower sides, and the ground surrounding each of the land patterns 5. It is preferable not to overlap the inner edge of the conductor layer or the power supply conductor layer 3.

  Further, the laminated substrate 9 has the above-described configuration, and the ground conductor layer or the power source conductor layer 3 is formed between the upper and lower ceramic insulating layers 1 when the inner edges surrounding the land pattern 5 do not overlap the upper and lower sides of the through conductors 4. Therefore, the ground pattern 5 surrounding the land pattern 5 or the land pattern 5 of the power supply conductor layer 3 that is likely to interfere with the close contact between the ceramic insulating layers 1 or to be subjected to stress such as stress due to a difference in shrinkage during firing. The position of the surrounding inner edge is also distributed vertically. Therefore, the upper and lower ceramic insulating layers 1 can be more closely adhered, and the occurrence of cracks in the ceramic insulating layer 1 can be more effectively suppressed.

  In this case, the inner edge surrounding the land pattern 5 of the ground conductor layer or the power supply conductor layer 3 is penetrated if the ceramic insulating layer 1 and the insulating substrate 2 are formed with the materials and dimensions as described above, for example. What is necessary is just to be about 50-300 micrometers apart above and below the conductor 4. For example, this distance may be set to be approximately the same as the distance between the outer edges of the land pattern 5 connected to the through conductor 4 and the above-described land pattern 5.

  Note that the laminated substrate 9 of the present invention may be one in which the through conductor 4 penetrates the insulating base 2 from the upper surface to the lower surface, for example, as shown in a sectional view in FIG.

  In this case, you may make it use the surface exposed to the upper surface and lower surface of the insulation base | substrate 2 among the penetration conductors 4 as a terminal for electrical connection with an electronic component or an external electric circuit, respectively. When the exposed surface of the through conductor 4 is used as such a terminal, the mounted electronic component can be electrically connected to an external electric circuit without forming the wiring conductor 6.

  Further, for example, a through conductor 4 is formed so as to penetrate from the upper surface to the lower surface of an insulating substrate 2 formed by laminating seven or more ceramic insulating layers 1 as shown in FIG. 2, and continuously between six or more layers. When the land pattern 5 is formed, the outer edges of all the land patterns 5 may not overlap each other. In this case, for example, each land pattern 5 may be formed in a circular shape, and these land patterns 5 may be arranged concentrically when viewed in plan. The circular land pattern 5 is partially distorted or slightly distorted, for example, for electrical connection with the wiring conductor 6 or prevention of an electrical short circuit. You may go out.

  Further, when the number of ceramic insulating layers 1 is increased to exceed, for example, 15 layers, and the land pattern 5 and the ground conductor layer or the power supply conductor layer 3 surrounding the land pattern 5 are formed between all layers, It may be difficult to prevent the outer edges of all the land patterns 5 from overlapping while reducing the size of the multilayer substrate 9 and securing the necessary ground conductor layer or power supply conductor layer 3 area. In such a case, for example, as shown in a cross-sectional view in FIG. 3, land patterns 5 of several types (four in the example shown in FIG. 3) are arranged in order of increasing (or decreasing) outer dimensions, and this The arrangement pattern may be repeated. FIG. 3 is an enlarged cross-sectional view of a main part showing another example of the embodiment of the laminated substrate 9 of the present invention. In FIG. 3, the same parts as those in FIG.

  As shown in FIG. 3, a laminated substrate 9 having a large number of laminated ceramic insulating layers 1 has a thickness of about 50 μm or less for each ceramic insulating layer 1 in order to reduce the thickness of the laminated substrate 9. It may be thin. In such a case, it is preferable to form conductors such as the ground conductor layer or the power supply conductor layer 3, the land pattern 5, and the wiring conductor 6 as thin as about 10 μm in order to more effectively suppress the adhesion failure between the layers.

  Further, in order to connect the ground conductor layer or the power supply conductor layer 3 up and down, a connection conductor 7 that penetrates the ceramic insulating layer 1 in the thickness direction may be formed separately from the through conductor 4. Further, the connection conductor 7 may have one end (for example, the lower end) connected to the ground conductor layer or the power supply conductor layer 3 and the other end (for example, the upper end) exposed to the upper surface of the insulating base 2 or the like.

  Further, in the multilayer substrate 9 of the present invention, for example, as shown in FIGS. 4 and 5, the size of the land pattern 5 connected to each of the adjacent through conductors 4 is different between the same layers of the ceramic insulating layer 1. In this case, it is possible to prevent the width of the ground conductor layer and the power supply conductor layer 3 from being partially narrowed between the adjacent through conductors 4. FIG. 4 is a cross-sectional view showing another example of the embodiment of the multilayer substrate 9 of the present invention. FIGS. 5A and 5B are AA of the multilayer substrate 9 shown in FIG. It is sectional drawing in a line and a BB line. 4 and 5, the same parts as those in FIG. 1 are denoted by the same reference numerals.

  That is, some of the land patterns 5 connected to the same through conductor 4 are larger than others in order to prevent the outer edges of the land patterns 5 from overlapping each other above and below the through conductor 4. Therefore, if the large land patterns 5 are adjacent to each other in the same layer, the width of the ground conductor layer and the power supply conductor layer 3 between the through conductors 4 becomes narrow, the electric resistance becomes high, and the potential of the ground and the power supply becomes unstable. There is a possibility. On the other hand, as described above, if the sizes of the land patterns 5 connected to the respective adjacent through conductors 4 are different from each other in the same layer of the ceramic insulating layer 1, a large land pattern is formed in the same layer. Since it is easy to prevent 5 from adjoining, it can suppress that the width | variety of a grounding conductor layer or the power supply conductor layer 3 becomes narrow, and can stabilize the electric potential of grounding or a power supply.

  For example, in the multilayer substrate 9, when the diameter of the through conductor 4 is 75 μm and the interval between the outer edges of the adjacent through conductors 4 is 450 μm, both the land patterns 5 connected to the respective through conductors 4 in the same layer have the diameter. If the distance between the land pattern 5 (outer edge) and the ground conductor layer 3 or the power supply conductor layer 3 (inner edge) is 50 μm, it is a circular pattern with a radius of about 200 μm (radius is 100 μm). The width of the ground conductor layer or the power supply conductor layer 3 is 450− (100−75 / 2) × 2− (50 × 2) = 225 μm.

  In this laminated substrate 9, in order to separate the diameters of both adjacent land patterns 5 from each other by 50 μm between the outer edges when viewed in plan with the other land patterns 5 above or below the through conductors 4, respectively. When the diameter of the land pattern 5 is increased to 300 μm between the same layers, the width of the ground conductor layer or the power supply conductor layer 3 between the adjacent through conductors 4 is 450− (150−75 / 2) × 2−2. (50 × 2) = 125 μm. Therefore, if the thickness of the ground conductor layer or the power supply conductor layer 3 is constant, the resistance increases about 1.8 (225/125) times in the narrow portion.

  Such an increase in resistance is in a narrow area of the ground conductor layer or the power supply conductor layer 3 having a relatively large area, but when the resistance is about 1.8 times when that portion is a current flow path, A part becomes obstructed and current becomes difficult to pass. Therefore, it may cause a decrease in electrical characteristics. Further, when there are a plurality of such narrow portions in one ground conductor layer or power supply conductor layer 3, the resistance further increases, and therefore the ground potential of the ground conductor layer or power supply conductor layer 3 or the potential of the power supply Is likely to be unstable.

  On the other hand, when the diameter of the land pattern 5 connected to one through conductor 4 of the adjacent through conductors 4 is 300 μm in the same layer, the land pattern 5 connected to the other through conductor 4 is used. The diameter of the ground conductor layer or the power supply conductor layer 3 between the adjacent through conductors 4 is 450− (150−75 / 2) − (50−75 / 2) − (50 × 2). ) = 225 μm, so that an increase in resistance can be suppressed.

  In order to prevent an increase in resistance due to such a narrow width of the ground conductor layer or power supply conductor layer 3, the outer edge of the land pattern 5 and the inner edge of the ground conductor layer or power supply conductor layer 3 surrounding the land pattern 5 are used. It is also conceivable that the distance between and is made narrower than the above-mentioned value (about 50 to 150 μm), for example. However, when the distance between the land pattern 5 (outer edge) and the ground conductor layer or the power supply conductor layer 3 (inner edge) is narrowed, there is a possibility that the electrical insulation between them decreases, and the laminated substrate 9 It is not suitable for increasing the reliability.

  A ceramic insulating layer made of a silicon oxide-magnesium oxide-magnesium oxide glass material and a glass ceramic sintered body mainly made of aluminum oxide and having a square plate shape with a side length of 12 mm and a thickness of 100 μm. 12 layers of insulating substrate, through conductors that continuously penetrate the ceramic insulation layer from the top layer to the bottom layer, land patterns that connect the through conductors of each ceramic insulation layer up and down, and each ceramic insulation layer A grounding conductor layer covering almost the entire surface of each of the layers (11 layers) was formed to produce the multilayer substrate of the present invention.

  In this laminated substrate, the through conductor was formed in a cylindrical shape having a diameter of 100 μm, and the land pattern was formed in two types, a circular shape having a diameter of about 250 μm and a circular pattern having a diameter of about 150 μm. The land patterns having different diameters are alternately arranged up and down so that the outer edges of the land patterns connected to the through conductors do not overlap with each other. The distance between the outer edges of the upper and lower land patterns was about 50 μm. The land pattern and the ground conductor layer were separated by a width of 100 μm and were electrically insulated from each other.

  The land pattern and the ground conductor layer were both formed with a thickness of 15 μm.

  The insulating substrate is made by mixing a raw material powder obtained by adding aluminum oxide powder to silicon oxide-magnesium oxide-magnesium oxide glass material powder together with an organic solvent and a binder, and then molding a ceramic green sheet by a doctor blade method. After 12 layers of ceramic green sheets were laminated, the laminate was produced by firing at 950 ° C.

  The through conductor, the land pattern, and the ground conductor layer were formed by cofiring with a ceramic green sheet laminate using a copper metallized layer. The copper metallized layer is a screen-printed printing method using a metal paste prepared by adding and kneading an organic solvent to copper powder to the surface of the ceramic green sheet and the through holes previously formed in the ceramic green sheet. Or it was formed by filling. The through hole was formed by a processing method using a metal pin.

  In addition, as a comparative example, a through conductor and a ground conductor similar to those of the multilayer substrate of the example were formed on an insulating base made of the same material and dimensions as those of the multilayer substrate of the example, and connected to the through conductor vertically. A layered substrate formed by making the shape and dimensions of the land pattern the same in the upper and lower sides (with the outer edges of the land pattern overlapping in the upper and lower sides) was produced.

  After the laminated substrates of this example and the comparative example were heated on the heater block (set temperature: 450 ° C.), the adhesion between the ceramic insulating layers (presence of adhesion failure) was confirmed and occurred in the ceramic insulating layer. The presence or absence of cracks was confirmed. The presence or absence of adhesion failure and cracks were confirmed by inspecting the inside of the insulating substrate by ultrasonic flaw detection. Ultrasonic flaw detection is an inspection method that uses an ultrasonic reflection pattern to detect minute spaces inside an insulating substrate that are generated in response to poor adhesion between layers or cracks in a ceramic insulating layer. It carried out using the flaw detector.

  For laminated substrates in which abnormalities (reflection of ultrasonic waves determined to be the space inside the insulating substrate) are detected by ultrasonic flaw detection, the insulating substrate is cut and the cut surface is polished at the portion where the abnormality is detected. Actually, the adhesion failure and the crack were confirmed by observation.

  The number of tests was 100 in both the examples and comparative examples.

  As a result, in the multilayer substrate in which the outer edges of the land pattern connected to the through conductor and the top and bottom are not vertically overlapped, which is an embodiment of the present invention, both the adhesion failure of the upper and lower ceramic insulating layers and the crack of the ceramic insulating layer are both It did not occur. On the other hand, in the comparative example, adhesion failure occurred in the upper and lower ceramic insulating layers (about 1 to 3 layers each) in about 12 laminated substrates. Further, in the comparative example, although no crack was generated in the ceramic insulating layer, it was observed that in each of the two laminated substrates, fine peeling occurred at a portion in contact with the interlayer of the ceramic insulating layer. It was.

  As a result, it can be seen that in the multilayer substrate of the present invention, it is possible to suppress problems such as poor adhesion and cracks in the ceramic insulating layer between the layers of the ceramic insulating layer as compared with the conventional multilayer substrate.

It is sectional drawing which shows an example of embodiment of the laminated substrate of this invention. It is sectional drawing which shows the other example of embodiment of the laminated substrate of this invention. It is sectional drawing which shows the other example of embodiment of the laminated substrate of this invention. It is sectional drawing which shows the other example of embodiment of the laminated substrate of this invention. (A) is the principal part expanded sectional view which expands and shows the cross section in the AA line of FIG. 4, (b) is the principal part expanded sectional view which expands and shows the cross section in the BB line of FIG. is there.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Ceramic insulation layer 2 ... Insulation base 2a ... Mounting part 3 ... Grounding conductor layer or power supply conductor layer 4 ... Penetration conductor 5 ... Land pattern 6 ... ..Wiring conductor 7 ... Connection conductor 9 ... Laminated substrate

Claims (1)

Three or more ceramic insulating layers are laminated to form an insulating base, and two or more continuous layers of the ceramic insulating layers are formed such that a ground conductor layer or a power supply conductor layer overlaps each other. In addition, a through conductor penetrating in a thickness direction through a portion of the ceramic insulating layer between the ground conductor layer or the power conductor layer where the ground conductor layer or the power conductor layer is not formed is the ground conductor layer or the power conductor layer. Formed electrically insulated,
Land patterns connected to the top and bottom of the through conductor are formed, and the outer edges of the land pattern do not overlap with the top and bottom of the through conductor ,
The ground conductor layer or the power supply conductor layer has an inner edge surrounding the land pattern that does not overlap above and below the through conductor,
The multilayer substrate , wherein the size of the land pattern connected to each of the adjacent through conductors is different from each other in the same layer of the ceramic insulating layer .

Images