JP2006210938A - Method for manufacturing circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a circuit board in which cracks, delaminations and curvatures can be suppressed, and at the same time, the flexibility of layer construction which has been impossible in prior art can be improved dramatically, by adjusting burning contraction behavior at high levels, when different materials are burned at same time. <P>SOLUTION: A laminated mold body are manufactured by laminating a first insulating layer mold body and a second insulating layer mold body which consist of different materials, and the laminated mold body is burned. In the method for manufacturing the circuit board, in which first insulating layers 1a and 1g and second insulating layers 1b to 1f are laminated, at least one or more sorts of common crystal phases are generated, by making the first insulating layers 1a and 1g and the second insulating layers 1b to 1f burned. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method of manufacturing a circuit board. For example, an insulating layer having a high relative dielectric constant in a microwave band and a high Q value and an insulating layer having a low relative dielectric constant are simultaneously fired and integrated. The present invention relates to a method of manufacturing a circuit board incorporating functional elements such as capacitors and inductors.

  Conventionally, in order to reinforce a weak insulating layer with a strong insulating layer, or to incorporate a capacitor with a high capacitance value in a circuit board, an insulating layer and a different material insulation made of a material different from this insulating layer are used. A circuit board in which layers are stacked is known (for example, see Patent Document 1).

  In such a circuit board, the insulating layer and the dissimilar material insulating layer are formed of a glass ceramic composed of a ceramic filler and glass, and by controlling the ceramic filler and the glass material, the firing shrinkage rate and the thermal expansion coefficient are brought closer. , Cracks, delamination and warpage were suppressed.

  And in such a circuit board, since it heat-fires so that Ag or Cu can be used as an electrode, an insulating layer and a dissimilar material insulating layer are glass main components, and glass and a filler component almost react. The firing shrinkage behavior was mainly governed by the flow due to the high temperature viscosity change of the glass component and the wettability with the filler.

  In recent years, circuit boards incorporating functional elements such as resonators, capacitors, and inductors have been incorporated into various electronic devices such as mobile phones. Circuit boards are mainly used in the microwave band, and there is a high demand for downsizing and high performance from electronic devices including mobile phones in recent years.

For example, a high relative dielectric constant of the insulating layer is desired for downsizing the resonator, and a high material Q value is desired for low loss. In addition, it is desired that the dielectric layer has a low dielectric constant for impedance matching and suppression of unnecessary interference between circuits. Therefore, by forming the circuit board with two or more types of insulating layers that satisfy such requirements, restrictions on circuit design can be eliminated.
JP 59-194493 A

  However, since it was impossible to completely match the firing shrinkage behavior between different materials with the conventional method, even if cracks and delamination could be suppressed, warping was not necessary to eliminate the warpage of the substrate. Insulating dissimilar materials, such as a combination of insulating layers of dissimilar materials that cancel each other, for example, symmetrically laminating insulating layers and dissimilar material insulating layers around the center in the thickness direction of the substrate. Many restrictions have arisen in the order of lamination | stacking (layer structure) in the case of laminating | stacking a layer.

  Therefore, even in circuit design, it is unavoidable to carry out in a limited layer configuration, and the merit of using different materials in miniaturization, thinning, and multi-functioning is not fully utilized. It was the current situation.

  The present invention can suppress cracks, delamination and warpage by matching the firing shrinkage behavior at a high level at the time of simultaneous firing of different materials, and drastically increases the degree of freedom of the layer structure that was impossible in the past. It is an object of the present invention to provide a circuit board manufacturing method that can be improved.

  The method for producing a circuit board according to the present invention includes producing a laminated molded body in which a first insulating layer molded body and a second insulating layer molded body having different main crystal phases are laminated, firing the laminated molded body, and forming a first insulating layer. In the method for manufacturing a circuit board on which the second insulating layer is laminated, the first insulating layer and the second insulating layer are baked to generate at least one common crystal phase.

  By adopting such a manufacturing method, a common crystal phase is generated at the time of simultaneous firing of the first insulating layer molded body and the second insulating layer molded body. Therefore, the first insulating layer molded body and the second insulating layer molded body are formed. Are firmly bonded and contain the same common crystal phase, the thermal expansion coefficients of the first insulating layer and the second insulating layer approach, and the shrinkage behavior including the firing shrinkage start temperature and shrinkage end temperature approaches, As a result, even if the first insulating layer and the second insulating layer are simultaneously fired and integrated, warpage and delamination can be reduced.

In such a manufacturing method, the same crystalline body phase as the main crystalline phase of the first insulating layer compact is present in the first insulating layer, and the X-ray diffraction measurement of the common crystal phase in the first insulating layer is performed. The intensity ratio (I ₁ / I ₂ ) between the main peak intensity I _{1 in} the X-ray diffraction measurement and the main peak intensity I ₂ in the X-ray diffraction measurement of the compact crystal phase in the first insulating layer is 0.5 or more, and In the second insulating layer, the same crystalline body phase as the main crystalline phase of the second insulating layer molded body is present, and the main peak intensity I in the X-ray diffraction measurement of the common crystal phase in the second insulating layer ₃ and the main peak intensity I4 in the X-ray diffraction measurement of the molded crystal phase in the second insulating layer (I ₃ / I ₄ ) is preferably 0.5 or more.

That is, in the first insulating layer and the second insulating layer, the same crystalline body phase as the main crystalline phase in each of the first insulating layer molded body and the second insulating layer molded body exists, and the first insulating layer And main peak intensities I ₁ and I ₃ in X-ray diffraction measurement of the common crystal phase in each of the first and second insulating layers, and X-ray diffraction of each of the compact crystal phases in the first and second insulating layers. It is desirable that the intensity ratio (I ₁ / I ₂ , I ₃ / I ₄ ) with the main peak intensities I ₂ and I ₄ in measurement is 0.5 or more.

  By adopting such a configuration, the amount of the common crystal phase in the first insulating layer and the second insulating layer increases, and the thermal expansion coefficients of the first insulating layer and the second insulating layer become closer. Further, the shrinkage behavior including the firing shrinkage start temperature and the shrinkage end temperature approaches, and as a result, even if the first insulating layer and the second insulating layer are simultaneously fired and integrated, warpage and delamination can be further reduced.

  In the method for producing a circuit board according to the present invention, since a common crystal phase exists in the first insulating layer and the second insulating layer, the thermal expansion coefficients of the first insulating layer and the second insulating layer approach and the firing shrinkage start temperature The shrinkage behavior including shrinkage end temperature approaches between different materials. As a result, even if the first insulating layer and the second insulating layer are simultaneously fired and integrated, the warp and delamination can be reduced, and the layer structure has a high degree of freedom. Can be realized.

  FIG. 1 shows an example of a circuit board obtained by the manufacturing method of the present invention. In FIG. 1, the circuit board includes a substrate 1, a surface conductor 2 formed on the surface of the substrate 1, and the inside of the substrate 1. The formed inner layer conductor 3, via hole conductor 4, and insulating film 5 covering a part of the surface conductor 2 are formed.

  The substrate 1 is composed of seven insulating layers 1a to 1g, and an inner layer conductor 3 is formed between the insulating layers 1a to 1g. Insulator layers 1a to 1g are formed with via-hole conductors 4 for connecting the inner-layer conductors 3 in the thickness direction and for connecting the inner-layer conductor 3 and the surface conductor 2.

  The substrate 1 is composed of seven insulating layers 1a to 1g, and is made of a material different from the second insulating layers 1b to 1f, with the ground conductor 6 sandwiched between the upper and lower surfaces of the laminate composed of the second insulating layers 1b to 1f. First insulating layers 1a and 1g made of are laminated. The ground conductor 6 may not be formed between the second insulating layers 1b to 1f and the first insulating layers 1a and 1g. A λ / 4 stripline resonator 7 including an inner layer conductor 3 and a via hole conductor 4 is formed on the second insulating layer 1 f of the substrate 1. Here, the heterogeneous material means a material made of materials having different components and compositions.

The substrate 1 includes low dielectric constant first insulating layers 1a and 1g, and high dielectric constant and high Q value second insulating layers 1b to 1f. These first insulating layers 1a and 1g The second insulating layers 1b to 1f have a common common crystal phase, and the amount of glass in each of the first insulating layers 1a and 1g and the second insulating layers 1b to 1f is 20% by weight or less. Yes. The glass amount is particularly preferably 3 to 12% by weight because of the improvement of the Q value and the sinterability. Here, the glass is preferably an alkaline earth borosilicate glass containing a sintering aid (B ₂ O ₃ , Li ₂ O).

The first insulating layer 1a, the 1g and the second insulating layer 1B～1f, are present as _{(Mg, Ti) 2 (BO} 3) common crystal phase O is common. This (Mg, Ti) ₂ (BO ₃ ) O exists in the vicinity of 2θ = 35 degrees in the X-ray diffraction measurement using the Kα ray of Cu.

The first insulating layers 1a, 1g and the second insulating layers 1b-1f are at least one of RTiO ₃ , BaTi ₄ O ₉ , Mg ₂ SiO ₄ , RZrO ₃ , Al ₂ O ₃ , SnTiO ₄ and ZrTiO ₄ (however, R is composed of an alkaline earth metal element) as a main component, and the second component contains at least one of B ₂ O ₃ , Li ₂ O, and RO (where R is an alkaline earth element). The first insulating layers 1a and 1g have a dielectric constant of 10 or less, and the second insulating layers 1b to 1f have a dielectric constant of 15 or more.

As the first insulating layers 1a and 1g, those containing Mg ₂ SiO ₄ —MgTiO _{3 as a} main component and B ₂ O ₃ , Li ₂ O, SiO ₂ , CaO, and BaO as the second component are desirable. With such a composition, the first insulating layers 1a and 1g can have a dielectric constant of 10 or less.

In particular, as the first insulating layers 1a and 1g, when expressed as (1-x) Mg ₂ SiO ₄ .xMgTiO ₃ , x is a main component satisfying 0 ≦ x ≦ 0.8, and the main component 100 B is ₃ to 20 parts by weight in terms of B ₂ O ₃ with respect to parts by weight, Li is 1 to 10 parts by weight in terms of Li ₂ CO ₃ , Si is 0 to 30 parts by weight in terms of SiO ₂ , alkaline earth metal Is preferably 1 to 5 parts by weight in terms of oxide. In this case, Mg ₂ SiO ₄ is generated as the main crystal phase, Li ₂ TiSiO ₅ , (Mg, Ti) ₂ (BO ₃ ) O is generated, and in addition, MgTiO ₃ , TiO ₂ , SiO _2, etc. May also generate.

Here, the molar ratio x between Mg ₂ SiO ₄ and MgTiO ₃ is set to 0 ≦ x ≦ 0.8. When x exceeds 0.8, the proportion of MgTiO ₃ having a high dielectric constant increases. This is because the relative dielectric constant increases. In particular, x is preferably 0 ≦ x ≦ 0.5 from the viewpoint of reducing the dielectric constant of the dielectric ceramic. Further, for example, when a laminated body of the first insulator layer of the present invention and the MgTiO ₃ —CaTiO ₃ -based second insulator layer is manufactured, x is 0 <x from the viewpoint of close firing shrinkage behavior. ≦ 0.5 is desirable.

Moreover, the reason why B is contained in an amount of 3 to 20 parts by weight in terms of B ₂ O ₃ with respect to 100 parts by weight of the main component is that low-temperature firing becomes difficult when the amount of B ₂ O ₃ equivalent is less than 3 parts by weight. This is because simultaneous firing with a conductor containing Ag or Cu as a main component becomes difficult. Conversely, when the amount exceeds 20 parts by weight, the ratio of the glass phase in the sintered body increases and the Q value decreases. Therefore, it is desirable to contain 5 to 15 parts by weight of B in terms of B ₂ O ₃ from the viewpoint of maintaining sinterability and obtaining a high Q value. Examples of the boron-containing compound include metal boron, B ₂ O ₃ , collimite, CaB ₂ O ₄ , borosilicate glass, borosilicate alkali glass, and borosilicate alkaline earth glass.

Also the Li containing 1 to 10 parts by weight _Li 2 CO ₃ terms, the conductor when _Li 2 CO ₃ equivalent amount is less than 1 part by weight of the main component Ag or Cu becomes difficult low temperature sintering This is because co-firing becomes difficult, and conversely when the amount exceeds 10 parts by weight, the Q value decreases. From the viewpoint of sinterability and Q value, the Li ₂ CO ₃ equivalent amount of Li is preferably 4 to 9 parts by weight.

Further it was added 0-30 parts by weight in terms of SiO ₂ Si, when calculated as SiO ₂ amount exceeds 30 parts by weight, because the Q value is lowered the proportion of the glass phase is reduced. From the viewpoint of the Q value, it is desirable to contain 10 parts by weight or less of Si in terms of SiO ₂ .

  Moreover, the reason why 1 to 5 parts by weight of an alkaline earth metal (Mg, Ca, Sr, Ba) is contained in terms of oxide is 1 weight in terms of oxide with respect to 100 parts by weight of the main component. If it is less than the part, the shrinkage start temperature in the sintering process is as high as about 870 ° C., and the effect of addition cannot be obtained. On the other hand, when it exceeds 5 parts by weight, the Q value decreases. In particular, from the viewpoint of sinterability and Q value, the alkaline earth metal is preferably contained in a total amount of 1.5 to 3.5 parts by weight in terms of oxides (MgO, CaO, SrO, BaO). Alkaline earth metals are desirable because Ba and Ca have high Q values.

Further, from the viewpoint of improving the sinterability, it is desirable to further contain 0.1 to 15 parts by weight of Mn in terms of MnO ₂ with respect to 100 parts by weight of the main component. When Mn is added in an amount of 0.1 to 15 parts by weight in terms of MnO ₂ , the addition effect is small when the amount is less than 0.1 part by weight, and the dielectric property is deteriorated when the amount is more than 15 parts by weight. Because it does. It is desirable to contain 1.2 to 7 parts by weight of Mn in terms of MnO ₂ .

  Such a first insulating layer can have a firing temperature of 920 ° C. or lower, a relative dielectric constant of 9.1 or lower, and a Qf value of 5000 or higher.

The second insulating layers 1b to 1f are preferably composed of MgTiO ₃ —CaTiO ₃ as a main component and B ₂ O ₃ , Li ₂ O, SiO ₂ , CaO, BaO as the second component.

In particular, as the second insulating layer 1B～1f, when containing at least Mg and Ti as the metal element, a composition formula of these molar ratios, expressed as _{(1-x) MgTiO 3 ·} xCaTiO 3, wherein x is B is ₃ to 20 parts by weight in terms of B ₂ O ₃ and alkali metal is 1 to 10 in terms of alkali metal carbonate with respect to 100 parts by weight of the main component satisfying 0 ≦ x ≦ 0.2. parts, 0.01-5 parts by weight of Si in terms of SiO _2, an alkaline earth metal which contains 0.1 to 5 parts by weight alkaline earth metal oxides in terms desirable. In this case, in the second insulating layers 1b to 1f, MgTiO ₃ is generated as a main crystal phase and (Mg, Ti) ₂ (BO ₃ ) O is generated. The common crystal phase common to the first insulating layers 1a and 1g is (Mg, Ti) ₂ (BO ₃ ) O.

  Here, x is set to 0 ≦ x ≦ 0.2 because when x exceeds 0.2 mol, the temperature coefficient τf of the resonance frequency becomes too large on the plus side. In particular, from the viewpoint of the temperature coefficient τf of the resonance frequency of the dielectric ceramic, x is preferably 0.03 ≦ x ≦ 0.13.

Further, with respect to 100 parts by weight of the main component, B from containing 3 to 20 parts by weight terms _{of B} 2 _{O 3,} when B is less than 3 parts by weight terms _{of B} 2 _{O 3} it is difficult to low temperature sintering This is because co-firing with a conductor containing Ag or Cu as a main component becomes difficult. Conversely, when the amount exceeds 20 parts by weight, the ratio of the glass phase in the sintered body increases and the Q value decreases. Therefore, it is desirable that B is contained in an amount of 5 to 15 parts by weight in terms of B ₂ O ₃ from the viewpoint of maintaining sinterability and obtaining a high Q value. Examples of the B-containing compound include metal boron, B ₂ O ₃ , collimite, CaB ₂ O ₄ , borosilicate glass, borosilicate alkali glass, and borosilicate alkaline earth glass.

  Also, the alkali metal contained in an amount of 1 to 10 parts by weight in terms of alkali metal carbonate is less than 1 part by weight, making low-temperature firing difficult and simultaneous firing with a conductor mainly composed of Ag or Cu difficult. On the other hand, if the amount exceeds 10 parts by weight, the crystal phase changes and the Q value decreases. From the viewpoint of improving the Q value, 4 to 9 parts by weight is desirable. Examples of the alkali metal include Li, Na, and K. Among these, Li is particularly desirable. Examples of the alkali metal-containing compound include carbonates and oxides of the above alkali metals.

Furthermore, Si is contained in an amount of 0.01 to 5 parts by weight in terms of SiO _{2. When} the content is less than 0.01 parts by weight, the shrinkage start temperature in the sintering process is as high as about 840 ° C. It is because it cannot be obtained. On the other hand, if it exceeds 5 parts by weight, the relative dielectric constant εr or the Q value decreases. From the viewpoint of the relative dielectric constant εr or Q value of the dielectric ceramic, 0.5 to 3 parts by weight is desirable. Examples of the Si-containing compound include SiO ₂ and MgSiO ₃ .

  Moreover, 0.1-5 weight part of alkaline-earth metal is contained in conversion of alkaline-earth metal oxide. When these are less than 0.1 part by weight, the shrinkage start temperature in the sintering process is higher than 830 ° C., and the effect of addition cannot be obtained. On the other hand, if it exceeds 5 parts by weight, the temperature coefficient τf of the resonance frequency becomes too large on the plus side. In particular, from the viewpoint of sinterability and the temperature coefficient τf of the resonance frequency, a total of 0.5 to 3.5 parts by weight is preferable. Examples of the alkaline earth metal include Mg, Ca, Sr, and Ba, and Ba is preferable among them. Examples of the alkaline earth metal-containing compound include carbonates and oxides of the above alkali metals.

Furthermore, from the viewpoint of improving sinterability, it is desirable to contain 0.1 to 3 parts by weight of Mn in terms of MnO ₂ with respect to 100 parts by weight of the main component. When Mn is added in an amount of 0.1 to 3 parts by weight in terms of MnO ₂ , the effect is not added when the amount is less than 0.1 part by weight, and the dielectric property is deteriorated when the amount is more than 3 parts by weight. Because it does. It is desirable to contain 1.2 to 1.8 parts by weight of Mn in terms of MnO ₂ .

  Such a second insulator layer can have a firing temperature of 920 ° C. or less, a relative dielectric constant of 18 or more, and a Qf value of 20000 or more.

The circuit board configured as described above produces a laminated molded body in which a first insulating layer molded body and a second insulating layer molded body made of different materials are laminated, and the laminated molded body is fired to obtain a first insulation. In the manufacturing method of the circuit board in which the layer and the second insulating layer are laminated, the first insulating layer and the second insulating layer are fired to generate at least one common crystal phase in common. In particular, it is desirable to generate a common crystal phase in which the common crystal phase is made of (Mg, Ti) ₂ (BO ₃ ) O.

  The first insulating layer and the second insulating layer are sintered by solid phase sintering of crystal particles, liquid phase sintering by glass, and further by reactive sintering by precipitation of a common crystal phase. The second insulator layer is bonded by diffusion bonding using a common crystal phase.

  Laminated molded products are produced by laminating green sheets produced by the doctor blade method, etc., or produced by sequentially applying ceramic paste, and further, applying ceramic paste, photocuring, developing, etc. Can be produced using a so-called photolithography technique.

  Specifically, for example, green sheets to be a first insulating layer molded body and a second insulating layer molded body are produced. The green sheet is made into a slurry by mixing a predetermined ceramic powder, an organic binder, an organic solvent, and, if necessary, a plasticizer. Using this slurry, tape is formed by a doctor blade method or the like, and cut into a predetermined size to produce a green sheet.

  Next, a through-hole serving as a via-hole conductor that connects the internal conductors is formed by punching or the like at a predetermined position of the green sheet. The conductive paste is filled in the through holes of the green sheet, and a conductor film that becomes an inner conductor of a predetermined shape is printed on the green sheet.

  Next, using a conductive paste, a conductor film to be a surface conductor of a predetermined shape is printed and formed on a green sheet to be a first insulating layer molded body of the surface layer.

  The green sheets thus obtained are laminated according to the lamination order, a laminated molded body is formed, and fired integrally. The circuit board is manufactured by the above manufacturing process.

And in the 1st insulating layer and the 2nd insulating layer, while the 1st insulating layer forming object and the 2nd insulating layer forming object have the same formation crystal phase as each main crystal phase, the 1st insulating layer X-ray diffraction measurement of main peak intensities I ₁ and I ₃ in X-ray diffraction measurement of the common crystal phase in each of the first insulating layer and the second insulating layer, and the crystal phase of each compact in the first insulating layer and the second insulating layer. It is desirable that the intensity ratio (I ₁ / I ₂ , I ₃ / I ₄ ) with the main peak intensities I ₂ and I ₄ is 0.5 or more.

That is, the first insulating layer 1a, and the main peak intensity I ₁ of the X-ray diffraction measurement of common crystalline phase in 1g, the intensity ratio between the main peak intensity I ₂ of the compact crystalline phase of the first insulating layer (I ₁ / I ₂ ) is 0.5 or more, and the main peak intensity I ₃ in the X-ray diffraction measurement of the common crystal phase in the second insulating layers 1b to 1f and the main crystalline phase in the second insulating layer The intensity ratio (I ₃ / I ₄ ) of the peak intensity I ₄ is 0.5 or more.

This is because cracks and delamination can be further suppressed by setting the strength ratios (I ₁ / I ₂ , I ₃ / I ₄ ) to be 0.5 or more.

On the other hand, when the intensity ratio (I ₁ / I ₂ , I ₃ / I ₄ ) is less than 0.5, an intermediate layer is easily formed at the boundary surface between different materials after simultaneous firing, which causes the firing shrinkage behavior between different materials. This is because mismatches are likely to occur. In particular, the strength ratio (I ₃ / I ₄ ) of the second dielectric layer having a high dielectric constant is 0.7 or more in order to precisely match the firing shrinkage behavior between different materials without forming an intermediate layer, and a low dielectric constant The first insulating layer has a strength ratio (I ₁ / I ₂ ) of preferably 1.5 or more.

For example, as described above, Mg ₂ SiO ₄ —MgTiO _{3 is a} main component as the first insulating layers 1 a and 1 g, and B ₂ O ₃ , Li ₂ O, SiO ₂ , CaO, and BaO are included as the second component. The second insulator layers 1b to 1f are composed of MgTiO ₃ —CaTiO ₃ as a main component and B ₂ O ₃ , Li ₂ O, SiO ₂ , CaO, BaO as the second component. Is used, since the main crystal phase of the first insulating layer molded body is Mg ₂ SiO ₄ , the molded body crystal phase is Mg ₂ SiO ₄ , and the main crystal phase of the second insulating layer molded body is MgTiO 2. ₃ , the compact crystal phase is MgTiO ₃ , and the common crystal phase in the first insulating layers 1a and 1g and the second insulating layers 1b to 1f is (Mg, Ti) ₂ (BO ₃ ) as described above. ) O.

  In the circuit board manufacturing method as described above, since the second insulating layers 1b to 1f and the first insulating layers 1a and 1g forming the common crystal phase common to each other are simultaneously fired, the firing shrinkage behavior and the thermal expansion coefficient are brought close to each other. Therefore, it is possible to adopt a layer structure with a high degree of freedom and suppress warping, cracks and delamination.

  Further, in the circuit board of FIG. 1, the relative dielectric constants of the second insulating layers 1b to 1f can be made higher than the relative dielectric constants of the upper and lower first insulating layers 1a and 1g. By forming the λ / 4 stripline resonator 7 in ˜1f, it is possible to reduce the size of the resonator by shortening the line that is a constituent part of the resonator 7 and to reduce the size between the ground conductor 6 and the surface conductor 2. By disposing the first insulating layers 1a and 1g having a dielectric constant, stray capacitance generated between the ground conductor 6 and the surface conductor 2 can be reduced.

  FIG. 2 shows an example of the layer configuration of the circuit board. FIG. 2A shows a state in which the first insulating layers are formed one by one above and below the stacked second insulating layers of five layers. ) Is a state in which two first insulating layers are stacked on the top and bottom of one second insulating layer, and (c) is a two-layer first insulating layer on the upper surface of a stack of two second insulating layers. In the state where the first insulating layer is formed on the lower surface, (d) shows one layer of the first insulating layer above and below the first insulating layer formed between the two second insulating layers. (E) is a state where two second insulating layers are stacked, and two first insulating layers are stacked on the upper surface, and (f) is a state where three second insulating layers are stacked. (G) shows a state in which the first insulating layers are stacked one by one on the upper and lower sides, and (g) shows a state in which the second insulating layers are formed on the upper and lower sides of the one in which the five first insulating layers are stacked, (h ) Is 1 A state in which two second insulating layers are stacked above and below the first insulating layer, and (i) is a method in which two second insulating layers are stacked on the upper surface of two stacked first insulating layers. , A state in which one second insulating layer is laminated on the lower surface, (j) is a state in which first insulating layers and second insulating layers are alternately laminated, and (k) is an upper and lower side of three first insulating layers. Shows a state in which the second insulating layers are stacked one by one.

B ₂ O ₃ powder, Li ₂ CO ₃ powder, SiO ₂ powder, alkaline earth oxide (MgO, CaO, SrO, BaO) powder was added in the composition shown in Table 1 and produced using this. Glass frit and Mg ₂ SiO ₄ , MgTiO ₃ powder with a purity of 99% or more as raw materials are weighed so that x satisfies the value of Table 1 in (1-x) Mg ₂ SiO ₄ .xMgTiO ₃ , and organic binder The slurry to which the organic solvent was added was thinned by a doctor blade method to produce a green sheet, thereby producing a first insulating layer molded body. On the other hand, the composition shown in Table 1 was molded into a predetermined shape, fired at the temperature shown in Table 1, and the relative dielectric constant and Qf value were measured.

Further, the MgTiO ₃ powder 99% pure, and CaTiO ₃ powder, x is from weighed so as to satisfy the values in Table 2 in _{(1-x) MgTiO 3 ·} xCaTiO 3 by molar _ratio, B 2 _{O 3} Powder, alkali metal carbonate powder (Li ₂ CO ₃ , Na ₂ CO ₃ , K ₂ CO ₃ ), SiO ₂ powder, MnO ₂ powder, and alkaline earth oxide powder (MgO, CaO, SrO, BaO), were weighed so that the ratio shown in Table 2, the pure water as a medium, and mixed for 20 hours wet ball mill using ZrO ₂ balls.

  Next, the mixture was dried and calcined at 800 ° C. for 1 hour, and the calcined product was pulverized so that the pulverized particle size was 1 μm or less. A green sheet was prepared from the slurry obtained by kneading the powder and a binder by a doctor blade method to prepare a second insulating layer molded body. On the other hand, the composition shown in Table 2 was molded into a predetermined shape, fired at the temperature shown in Table 2, and the relative dielectric constant and Qf value were measured.

  Thereafter, through holes for producing via hole conductors in the green sheet are produced by punching or the like at predetermined positions of the first and second insulating layer molded bodies, and the conductive paste mainly composed of Ag is penetrated. The hole was filled and a conductor film serving as an inner conductor having a predetermined shape was formed by printing. On the other hand, a conductive film having a predetermined shape serving as a surface conductor was printed on a first insulating layer molded body serving as the uppermost layer and the lowermost layer using a conductive paste mainly composed of Ag, and dried.

  A plurality of second insulating layer molded bodies filled with a conductive paste and having a conductor film of a predetermined shape are stacked on the upper surface of the lowermost first insulating layer molded body, and then the uppermost first insulating layer The molded bodies were laminated to produce a laminated molded body.

  Thereafter, the binder was removed at 400 ° C. in the atmosphere, and further baked at 910 ° C. to produce a circuit board as shown in FIG. The insulating layers 1a to 1g had a thickness of 0.15 mm, and the circuit board had a length of 10 mm, a width of 10 mm, and a thickness of 1.2 mm.

The common crystal phase (Mg, Ti) ₂ (BO ₃ ) O (the main peak of the XRD pattern is (201)) formed in the first insulating layer and the second insulating layer, and the respective first insulating layer and second insulating layer The main peak intensity ratio was measured by X-ray diffractometry (XRD) using Cu Kα rays with the compact crystal phase existing in the layer from the time of preparation to after sintering. The crystal phase in the first insulating layer is mainly Mg ₂ SiO ₄ , (Mg, Ti) ₂ (BO ₃ ) O, MgTiO ₃ , and the crystal phase in the second insulating layer is mainly They were MgTiO ₃ and (Mg, Ti) ₂ (BO ₃ ) O.

Here, the compact crystal phase of the second insulating layer is MgTiO ₃ (the main peak of the XRD pattern is (104)), and the crystal crystal phase of the first insulating layer is Mg ₂ SiO ₄ (the main peak of the XRD pattern is (211). )).

Then, the main peak intensities I ₁ and I _{3 of the} common crystal phase (Mg, Ti) ₂ (BO ₃ ) O formed in the first insulating layer and the second insulating layer, and the compact crystal phase of the first insulating layer the main peak intensity _{I 3,} the intensity ratio of the main peak intensity _{I 4} of the compact crystalline phase of the second insulating layer _{(I 1} / I _2), determine the _(I 3 / _{I 4),} described in Table 3.

  Further, warpage, cracks, delamination, and the presence or absence of an intermediate layer at the boundary surface in the fabricated substrate were evaluated by polishing the substrate and observing with a metal microscope and a scanning electron microscope (SEM).

Sample No. 8, as the first insulating layer, a ceramic filler composed of 70% by weight of SiO ₂ and 30% by weight of MgTiO ₃ , and 12 parts by weight of B ₂ O ₃ and Li ₂ CO ₃ with respect to 100 parts by weight of the ceramic filler. A glass component containing 6 parts by weight was added.

  From Tables 1 to 3, in the sample of the present invention, the first insulating layer has a relative dielectric constant of 14 or less, and there are samples of 10 or less (No. 2, 4 to 7), and the Qf value is 10,000 or more. The second insulating layer has a relative dielectric constant of 19 or more and a Qf value of 22000 or more. Even when the first insulating layer and the second insulating layer are fired at the same time, warpage, cracks, and delamination occur. It turns out that it has not occurred.

  In contrast, sample no. In FIG. 8, a common crystal phase common to the first insulating layer and the second insulating layer is not generated, and thus simultaneous firing is possible, but between the first insulating layer and the second insulating layer is possible. Peeling occurred.

In FIG. The X-ray-diffraction measurement result of the 1st insulating layer and 2nd insulating layer in 2 was described. As is apparent from FIG. 3, (Mg, Ti) ₂ (BO ₃ ) O, which is a common crystal phase, is precipitated in the first insulating layer and the second insulating layer, and the compact crystal phase is formed in the first insulating layer. As Mg ₂ SiO ₄ , MgTiO ₃ is precipitated as a compact crystal phase in the second insulating layer, and I ₁ / I ₂ is 1.5 and I ₃ / I ₄ is 0.7. . Since the common crystal phase (Mg, Ti) ₂ (BO ₃ ) O can be fired at a low temperature and has a high Q value, it can be fired simultaneously with a conductor mainly composed of Ag, an Ag alloy, and Cu. It is possible to increase the Q value of the first insulating layer and the second insulating layer.

1 shows a cross-sectional view of a ceramic circuit board. It is explanatory drawing which shows the example of a layer structure of a ceramic circuit board. Sample No. It is a figure which shows the X-ray-diffraction result of 2 1st insulating layers and 2nd insulating layers.

Explanation of symbols

1a, 1g ... 1st insulating layer 1b-1f ... 2nd insulating layer

Claims (2)

A laminated molded body in which the first insulating layer molded body and the second insulating layer molded body having different main crystal phases were laminated, the laminated molded body was fired, and the first insulating layer and the second insulating layer were laminated. In the method for producing a circuit board, a method for producing a circuit board, wherein at least one common crystal phase is generated in the first insulating layer and the second insulating layer by firing. In the first insulating layer, there is a compact crystal phase identical to the main crystal phase of the first insulating layer compact, and the main peak intensity I in the X-ray diffraction measurement of the common crystal phase in the first insulating layer. ₁ and the intensity ratio (I ₁ / I ₂ ) between the main peak intensity I ₂ in the X-ray diffraction measurement of the crystal phase of the compact in the first insulating layer is 0.5 or more, and the second insulation The same crystalline phase as the main crystalline phase of the second insulating layer molded body is present in the layer, and the main peak intensity I ₃ in the X-ray diffraction measurement of the common crystalline phase in the second insulating layer, 2. The circuit according to claim 1, wherein the intensity ratio (I ₃ / I ₄ ) with respect to the main peak intensity I ₄ in the X-ray diffraction measurement of the crystal phase of the compact in the second insulating layer is 0.5 or more. Board manufacturing method.

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