JP5164670B2 - Wiring board and manufacturing method thereof - Google Patents

Description

  The present invention relates to a wiring board including a plurality of glass ceramic insulating layers and through conductors manufactured by simultaneous firing and a manufacturing method thereof.

  Conventionally, a wiring board for mounting a semiconductor element or the like uses ceramics such as alumina as a material for forming an insulating base (a plurality of insulating layers), and a refractory metal such as tungsten as a material for forming a wiring. It was.

  In contrast, wiring can be formed by simultaneous firing with a low-resistance metal (for example, Cu, Ag or Au) having a lower melting point than tungsten, which is superior in that the dielectric constant is lower than that of alumina ceramics. Glass ceramics have been attracting attention as a material for forming an insulating substrate adapted to the demand for higher integration of circuits.

  A wiring board using glass ceramics as an insulating base (a plurality of glass ceramic insulating layers) is formed by mixing an organic binder or the like with a glass ceramic raw material containing glass powder such as borosilicate glass and an inorganic filler, for example. After producing the green sheet, through holes are formed in the glass ceramic green sheet, and the through holes are filled with a paste for penetrating conductors mixed with a metal powder and an organic binder. A conductor pattern is printed at the position to form a wiring pattern. And after aligning and pressurizing and laminating a plurality of green sheets, the obtained laminate is heated in a humidified nitrogen atmosphere and subjected to a binder removal treatment (burning off the organic binder), followed by firing ( It is obtained by simultaneously firing a plurality of glass ceramic green sheets and a paste for through conductors.

  In the wiring board, along with the recent miniaturization, enlargement, and speeding up of silicon chips, the flip chip connection part on which the silicon chip is mounted is miniaturized and the number of terminals is increased, and the flip chip connection part is flattened. The demand for degree is also increasing.

In order to improve the flatness of the flip chip connection part in the wiring board, the softening point is 700 to 1000 ° C. with respect to the main component Cu as a copper metallized composition (conductor paste) for via-hole conductors (for through conductors). By containing the glass frit, the copper metallized composition filled in the via hole (paste for through conductor) and the glass ceramic porcelain (glass ceramic green sheet) can be fired simultaneously, and the shrinkage rate during the firing process ( It is known that a glass-ceramic wiring board can be obtained in which the sintering behavior) matches and the via-hole conductor does not protrude from the surface of the insulating substrate (for example, see Patent Document 1).
Japanese Patent Laid-Open No. 11-16418

  Generally, an organic binder is included in the through conductor paste as in the case of the glass ceramic green sheet. And since the main baking temperature is 900-1000 degreeC for the wiring board which has a wiring layer which has Cu as a main component, and a penetration conductor, binder removal temperature is normally adjusted in the narrow temperature range of 700-800 degreeC.

  As described above, since the binder removal temperature is adjusted within a narrow temperature range, there is a problem in that the binder removal failure may occur due to poor adjustment. Specifically, if the gas generated by the combustion of the residual carbon is not sufficiently discharged to the outside, a cavity by this gas is formed inside the through conductor, and the through conductor is formed on the surface of the insulating substrate by the formation of this cavity. It is a problem that it protrudes from.

  Here, the gas generated by the combustion of residual carbon is not sufficiently discharged to the outside because the through conductor formed in the surface glass ceramic insulating layer and the through conductor formed in the inner glass ceramic insulating layer are sintered. This seems to be due to the difference in behavior at the time of ligation. That is, the through conductor paste formed in the surface layer and the through conductor paste formed in the inner layer have different amounts of heat applied during firing, so the through conductor paste formed in the surface layer is formed in the inner layer. Sintering starts before the paste, and when the through conductor paste formed on the surface layer is sintered, the through conductor paste formed on the inner layer is not yet completely sintered. In particular, when the thickness of the wiring board is thick, the debinding process is not completely completed within a predetermined holding time, and the residual carbon is burned (debinding process) even during the temperature increase of the main firing. Since the sintering is in progress, the binder removal treatment of the through conductor paste formed in the inner layer has not yet been completed even when the through conductor paste formed in the surface layer has been sintered. As a result, the gas generated thereby loses its place and lifts the through conductor formed on the surface layer.

  To cope with this problem, it is conceivable to set the debinding temperature to a low temperature (less than 700 ° C.) and extend the holding time at that temperature, but extending the holding time leads to a decrease in production efficiency. In particular, since the sintering start temperature of low resistance metals such as Cu and Ag is around 700 ° C., the longer the holding time in the low temperature range (below 700 ° C.), the better the binder removal efficiency, but the through conductor paste and glass Inconsistency in sintering behavior with the ceramic green sheet occurs. That is, even if a cavity is not formed inside the through conductor, there arises a problem that the through conductor protrudes from the surface of the insulating base due to this mismatch in sintering behavior.

  The present invention has been made in view of such circumstances, and provides a wiring board in which protrusion of the through conductor from the surface of the insulating base due to poor debinding and mismatched sintering behavior is suppressed, and a method for manufacturing the same. With the goal.

The present invention provides an insulating base formed by laminating three or more glass ceramic insulating layers, a wiring layer formed on the surface and inside of the insulating base, and a glass ceramic insulating layer constituting the inner layer. 1 through conductor and the glass ceramic insulating layer constituting the surface layer,
A wiring board including a second through conductor directly connected to the first through conductor, wherein the first through conductor and the second through conductor have the same metal as a main component in the same amount. A glass and a precipitated crystal, and the amount of the precipitated crystal contained in the second through conductor is larger than the amount of the precipitated crystal contained in the first through conductor. is there.

According to the present invention, there is provided a first through conductor paste comprising a glass powder in which a through-hole is formed, the glass powder not crystallizing substantially after firing, a glass powder partially crystallized after firing, and a metal powder. a step of preparing a first glass-ceramic green sheets filled, the through hole is formed, the glass powder partially crystallizes after firing the glass powder that does not substantially crystallize after firing through hole first The first through conductor paste containing the same amount of metal powder was filled with the second through conductor paste having a larger amount of glass powder that partially crystallized than the first through conductor paste. A step of producing a second glass ceramic green sheet; and disposing the first glass ceramic green sheet as an inner layer and disposing the second glass ceramic green sheet as a surface layer. A step of producing a laminated body in which the first through-conductor paste and the second through-conductor paste are directly connected to each other, and a step of firing the laminated body. A method for manufacturing a wiring board.

  According to the wiring board of the present invention, the first through conductor formed in the glass ceramic insulating layer constituting the inner layer and the second through conductor formed in the glass ceramic insulating layer constituting the surface layer are mainly made of the same metal. It contains glass and precipitated crystals as a component, and the amount of precipitated crystals contained in the second through conductor is larger than the amount of precipitated crystals contained in the first through conductor. A wiring board in which protrusion from the surface of the insulating base is suppressed can be realized.

  In addition, according to the method for manufacturing a wiring board of the present invention, the through hole formed in the second glass ceramic green sheet disposed on the surface layer contains a lot of glass powder that partially crystallizes after firing. The first through conductor paste containing a small amount of glass powder that partially fills the through hole formed in the first glass ceramic green sheet disposed in the inner layer and filled with the through conductor paste. By filling, a fine void is formed by volume shrinkage when the glass powder is crystallized in either through-conductor paste, but the void formed in the second through-conductor paste is the first. There are more voids formed in the through-conductor paste, and the sintering behavior of the second through-conductor paste is slower than the sintering behavior of the first through-conductor paste. In the process, the gap formed in the second through-conductor paste remains until later than the gap formed in the first through-conductor paste, and this gap becomes an escape path for the gas generated from the through-conductor paste, Protrusion of the second through conductor can be effectively suppressed.

  Note that the voids formed in the first and second through conductor pastes are almost disappeared by the subsequent holding (sintering) at the main firing temperature, so there is a risk of a decrease in reliability due to intrusion of moisture and the like. Absent.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view of an embodiment of a wiring board of the present invention.

  The wiring substrate shown in FIG. 1 includes an insulating substrate 1 formed by laminating a plurality of glass ceramic insulating layers 1a to 1i, a wiring layer 2 formed on and in the surface of the insulating substrate 1, and a glass ceramic insulation constituting an inner layer. A first through conductor 31 formed in the layers 1b to 1h and a second through conductor 32 formed in the glass ceramic insulating layers 1a and 1i constituting the surface layer and directly connected to the first through conductor 31. A wiring board provided.

  The insulating substrate 1 is composed of three or more glass ceramic insulating layers (in this example, nine glass ceramic insulating layers 1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i), and a crystal phase and glass It is formed of a glass ceramic sintered body having a phase. Examples of the crystalline phase include at least one of diopside, hardistonite, celsian, cordierite, anorthite, garnite, willemite, spinel, mullite, forsterite, and sourite. This crystal phase may be precipitated from glass powder as a raw material, or may be mixed as an inorganic filler as a raw material.

  A wiring layer 2 mainly composed of a low-resistance metal such as Cu or Ag is formed on the surface and inside of the insulating base 1, and differs depending on the first through conductor 31 or the second through conductor 32 described later. The wiring layer 2 provided in the layer and the wiring layer 2 are electrically connected.

  Of the plurality of glass ceramic insulating layers 1a to 1i, the first through conductor 31 is formed in the glass ceramic insulating layers 1b to 1h constituting the inner layer, and in the glass ceramic insulating layers 1a and 1i constituting the surface layer A second through conductor 32 that is directly connected to the first through conductor 31 is formed.

  Here, the first through conductor 31 and the second through conductor 32 are made of the same metal (low resistance metal such as Cu or Ag) as a main component, and are precipitated from glass and precipitated crystals (glass powder as a raw material). However, the amount of precipitated crystals contained in each through conductor is different. That is, the second through conductor 32 has a larger amount of precipitated crystals than the first through conductor 31 in mass ratio. Such a configuration is substantially obtained after firing as glass to be contained in the first through conductor paste for forming the first through conductor 31 and the second through conductor paste to be the second through conductor 32. A crystalline glass that does not precipitate crystals and a crystalline glass that partially crystallizes after firing, and the crystalline glass contained in the second through-conductor paste is used as the first through-conductor paste. What is necessary is just to increase more than the crystalline glass contained. In addition, that a crystal | crystallization does not precipitate substantially means that it is the quantity of the grade which the peak derived from the crystal | crystallization is not recognized in X-ray diffraction.

  Thus, since the amount of the precipitated crystal in the second through conductor 32 is larger than the precipitated crystal in the first through conductor 31, the amount of heat applied to the through conductor paste for forming each through conductor at the time of firing is reduced. It is possible to obtain a wiring board in which protrusion of the through conductor from the surface of the insulating base 1 due to a debinding failure caused by the difference is suppressed.

  Next, the manufacturing method of the wiring board of this invention is demonstrated.

  First, in order to form the insulating substrate 1, a glass ceramic green sheet is produced using only glass powder or glass powder and an inorganic filler. Specifically, this glass ceramic green sheet is prepared by adding a solvent, an organic binder for molding and the like to the above raw material powder and mixing to prepare a slurry, which is then treated by a doctor blade method, a calender roll method, a rolling method, etc. It can be formed by the method of.

As the glass powder, crystals composed of oxides such as SiO ₂ , MgO, CaO, BaO, Al ₂ O ₃ , ZnO in the sintering process, such as diopside, hardistonite, celsian, cordierite, It may be a crystalline glass in which at least one crystal is precipitated out of anorthite, garnite, willemite, spinel, mullite, forsterite, and sourite, and is an amorphous glass in which no crystal is precipitated in the sintering process. Also good. Specifically, in addition to borosilicate glass such as borosilicate glass, zinc borosilicate glass and lead borosilicate glass containing alkaline earth oxide, lithium silicate glass and the like can be given. As the inorganic filler, oxides such as Al ₂ O ₃ , SiO ₂ , ZrO ₂ , CaO, MgO or MgO, or composite oxides of two or more of these oxides can be used. By adjusting the mixing ratio of the glass powder and the inorganic filler, the firing temperature of the glass ceramic sintered body can be matched with the firing temperature of the paste for through conductors, or the strength of the glass ceramic sintered body itself can be increased. It is effective that the ratio of the glass powder and the inorganic filler is, for example, 20:80 to 80:20 by volume ratio.

  Next, a through hole is formed at a predetermined position of the obtained glass ceramic green sheet, and a through conductor paste is filled in the through hole. This through-conductor paste is obtained by adding glass powder, an organic binder, a solvent, a dispersant, and the like to a metal powder mainly composed of a low resistance metal such as Cu or Ag.

  Here, the through-conductor paste (first through-conductor paste) filled in the through-hole formed in the inner-layer glass-ceramic green sheet (first glass-ceramic green sheet) and the surface-layer glass-ceramic green sheet The amount of glass powder made of crystalline glass is different from the through conductor paste (second through conductor paste) filled in the through holes formed in the (second glass ceramic green sheet). That is, the amount of glass powder made of crystalline glass contained in the second through conductor paste is larger than the amount of glass powder made of crystalline glass contained in the first through conductor paste.

As the glass powder used for the first through conductor paste and the second through conductor paste, borosilicate glass containing SiO ₂ and B ₂ O ₃ is preferably used, and the glass transition point and the crystal after firing are used. For the purpose of adjusting the presence or absence of phase precipitation, various alkali metal oxides, alkaline earth metal oxides, Al ₂ O ₃ , ZnO or ZrO ₂ and the like are used, and the mixing ratio thereof is arbitrarily selected. can do.

  In addition, the glass transition point is preferably 600 ° C. or higher so that the binder component contained in the through conductor paste can be efficiently removed from the binder, and the glass transition point is 800 ° C. or lower in terms of densification of the through conductor. It is preferable.

Furthermore, the glass powder used for the first through conductor paste and the second through conductor paste is a mixture of an amorphous glass that does not precipitate a crystalline phase after firing and a crystalline glass that precipitates a crystalline phase. This is very important. The non-crystalline glass, for example, a SiO ₂ 45 wt%, a BaO 30 _wt%, B 2 _{O 3} 10 wt%, the _Al 2 _{O 3} 10 wt%, amorphous composed of CaO from 5 wt% Glass (a crystal phase is not precipitated after firing at a glass transition point of 680 ° C.) can be used. As the crystalline glass, alkali metal oxides or alkaline earth metal oxides and SiO ₂ , or alkali metal oxides or alkaline earth metal oxides and SiO ₂ , Al ₂ O ₃ are close to the stoichiometric composition. A composition in which B ₂ O ₃ and other components are externally added thereto can easily precipitate a crystal phase. For example, 45% by mass of SiO ₂ , 30% by mass of Al ₂ O ₃ , and 10% of MgO A glass composed of 10% by mass, 10% by mass of B ₂ O ₃ and 5% by mass of ZnO (glass transition point 720 ° C., cordierite and garnite are precipitated after firing) can be mentioned.

The amount of glass to be added is preferably 3 to 20 parts by mass with respect to 100 parts by mass of Cu contained in the through conductor, and is made of a crystalline material for the purpose of adjusting the difference in sintering behavior between the through conductor paste and the glass ceramic green sheet. A filler (for example, SiO ₂ or Al ₂ O ₃ ) can be added up to 2 parts by mass.

  In order to obtain the effects of the present invention more remarkably, the glass transition point and crystallization point of the glass powder contained in the second through conductor paste are the glass transition point of the glass powder contained in the first through conductor paste. Or the total amount of glass powder contained in the second through conductor paste is preferably larger than the total amount of glass powder contained in the first through conductor paste.

  According to this configuration, the sintering of the second through conductor paste is slower than the sintering of the first through conductor paste. Here, when crystals are precipitated from the glass, fine voids are generated and the number of contacts between the metal powders is reduced, so that sintering is inhibited. When the amount of crystal precipitation from the glass contained in the second through-conductor paste is larger than the amount of crystal precipitation from the glass contained in the first through-conductor paste, the second through-conductor paste is the first Sintering is slower than the paste for through conductors.

Whether the glass is a crystalline glass or an amorphous glass (whether or not crystals are precipitated after firing) is related to the constituent components of the glass. Specifically, when the amount of SiO ₂ or B ₂ O ₃ is increased, crystals tend not to precipitate after firing, and the amount of alkali metal, alkaline earth metal, Al ₂ O ₃ , ZrO ₂ or the like is large. If it becomes, it exists in the tendency for a crystal | crystallization to precipitate easily after baking. In particular, when a part of the composition constituting the glass has a stoichiometric composition ratio, crystals are likely to precipitate.

  Next, in order to form a wiring layer on the surface of the glass ceramic green sheet, a conductor paste containing a metal powder mainly composed of a low resistance metal such as Cu or Ag and a glass powder is screen printed in a circuit pattern. And printing by the gravure printing method. In addition, 1-10 mass parts of glass powder is added to 100 mass parts of metal powders in this conductor paste.

  Then, the glass ceramic green sheet formed as described above is laminated so that the first glass ceramic green sheet is arranged in the inner layer and the second glass ceramic green sheet is arranged in the surface layer, and the laminated body Is made. At this time, the first through-conductor paste and the second through-conductor paste are laminated so as to be directly connected.

  Finally, the laminate was held in humidified nitrogen at a temperature of 600 to 700 ° C. for several hours to perform a binder removal treatment, followed by main firing at a temperature of 850 to 1050 ° C. in the same atmosphere. The wiring board of the present invention is produced by simultaneously firing the sheet, the paste for through conductors, and the conductor paste.

  Preferably, for the purpose of preventing oxidation of the wiring layer 2 on the surface, a metal plating layer of Ni, Au, Cu or the like is formed to a thickness of 1 to 10 μm on the surface after firing by a technique such as electrolytic plating or electroless plating. It is formed.

  Here, the mechanism of debinding failure occurrence and its suppression will be described in detail.

  In the present invention, the influence of the crystalline glass that crystallizes after firing and the amorphous glass that does not crystallize after firing on the sintering behavior of the paste for through conductors is important. That is, the crystalline glass exhibits the same sintering behavior as that of the amorphous glass until crystals are precipitated. However, when crystals are precipitated from the glass during sintering (firing shrinkage), the sintering behavior of the crystalline glass is different from that of the amorphous glass.

In the amorphous glass, the first through-conductor paste starts sintering (firing shrinkage) as the glass softens as the firing temperature increases. At this time, since the glass is not crystallized, it has a function of relieving stress due to a difference in sintering behavior between the paste for penetrating conductor and the glass ceramic green sheet, and extremely good matching of the sintering behavior can be obtained. However, the non-crystalline glass tends to take in residual carbon that could not be scattered during the debinding process as the glass softened, and if these were exposed to the atmosphere in some way during the main firing, There is a problem that CO ₂ gas is generated by the combustion of carbon. Here, the matching of the sintering behavior means that the sintering curve in the sintering curve draws a similar curve.

On the other hand, in crystalline glass, density changes occur when crystals are precipitated from the glass. When a crystal composed of an element having a higher molecular weight than SiO ₂ or B ₂ O ₃ which is a main component constituting glass is precipitated, the density of the precipitated crystal becomes higher. Due to this density change, minute voids are formed around the precipitated crystals. In addition, if minute voids are generated and the number of contacts between metal powders is reduced, sintering is inhibited, and the sintering curve becomes gentle (burning is worsened). The minute gap functions as a vent and plays a role of suppressing a debinding failure.

  According to the present invention, since the amount of crystalline glass contained in the second through-conductor paste on the surface layer is larger than the amount of crystalline glass contained in the first through-conductor paste on the inner layer, the second The through-conductor paste has a larger amount of fine voids than the first through-conductor paste, resulting in fewer contacts between the metal powders. As a result, the sintering is inhibited, and the second through conductor paste is slower in sintering than the first through conductor paste.

  Therefore, in the wiring board of the present invention, even if the above gas is generated from the through conductor paste, the gas is improved by the small gaps formed in the second through conductor paste. It is possible to suppress the second through conductor 42 from being discharged from the surface of the insulating base 1 as shown in FIG. In particular, in a wiring board having a thickness exceeding 2 mm, the effect of suppressing protrusion due to this debinding defect becomes remarkable.

  Thus, according to the method for manufacturing a wiring board of the present invention, many minute voids are formed due to volume shrinkage when the glass powder in the second paste for through conductors is crystallized. These many voids serve as escape paths for the gas generated from the through conductor paste, and the protrusion of the second through conductor from the surface of the insulating base can be effectively suppressed. Since the amount of crystalline glass contained in the first through-conductor paste is less than the amount of crystalline glass contained in the second through-conductor paste, the through-conductor paste, the glass ceramic green sheet, The inconsistency in the sintering behavior is suppressed as much as possible.

  The wiring board manufactured as described above has a very excellent flatness, and can be efficiently mounted when an electronic component such as a silicon chip is mounted.

  The evaluation board | substrate which evaluates the effect of this invention was produced as follows. This evaluation substrate is a laminate of 24 glass ceramic insulating layers having a width of 50 mm × 50 mm and a thickness of 2.4 mm. A through conductor having a diameter of 60 μm is arranged in the center of the substrate with 110 rows × 110 columns at intervals of 180 μm. A total of 12100 are arranged, and a land having a diameter of 90 μm is formed on each through conductor. The manufacturing method is shown below.

First, a glass ceramic green sheet to be a glass ceramic insulating layer was produced. 41 parts by mass of SiO ₂ , 20 parts by mass of MgO, 20 parts by mass of BaO, 8 parts by mass of Al ₂ O ₃ , 7 parts by mass of B ₂ O ₃ , ₂ parts by mass of CaO, 1 part by mass of SrO and ZrO A glass powder containing 1 part by mass of ₂ and a quartz powder are prepared, and these are weighed as 60% by mass of glass powder and 40% by mass of quartz powder, and acrylic resin as an organic binder, dioctyl phthalate as a plasticizer, and solvent A slurry prepared by adding toluene was molded by a doctor blade method to produce a glass ceramic green sheet having a thickness of 200 mm SQ and a thickness of 125 μm.

  Then, a through hole having a diameter of 70 μm was provided in the glass ceramic green sheet by punching.

  Next, first and second through conductor pastes were produced. The first through conductor paste is used for the first glass ceramic green sheet disposed in the inner layer, and the second through conductor paste is used in the second glass ceramic green sheet disposed in the surface layer. Is. 12 parts by mass of glass powder made of crystalline glass or amorphous glass having the composition shown in Table 1 is added to 100 parts by mass of Cu powder, and an acrylic resin as an organic binder and a mixed solution of terpineol and dibutyl phthalate as a solvent ( 80:20) by mass ratio was added and kneaded to prepare first and second through conductor pastes. Then, the two kinds of through-conductor pastes thus prepared were filled in the through holes provided earlier by screen printing.

  Subsequently, a conductor paste for a wiring layer was produced. Specifically, Cu powder and glass powder are prepared, acrylic resin is added as an organic binder to these powders, and a mixed solution of terpineol and dibutyl phthalate (80:20 by mass) is added and kneaded. Thus, a conductor paste for a wiring layer was produced. Then, the obtained wiring layer conductor paste was printed by a screen printing method as a land having a pattern with a diameter of 105 μm immediately above the through conductor paste.

  A laminated body was produced using the glass ceramic green sheet with the conductor paste thus obtained. The first glass ceramic green sheets were arranged one by one on the upper and lower sides (surface layer), and 22 second glass ceramic green sheets were arranged on the inner layer, and pressure lamination was performed at 45 ° C. and 4 MPa.

Subsequently, the laminate is placed on an Al ₂ O ₃ base plate and subjected to heat treatment at 700 ° C. in a humidified nitrogen atmosphere in order to decompose and remove organic components such as an organic binder. Firing was performed in the same atmosphere at 900 ° C. for 1 hour.

  The obtained substrate was subjected to electroless Ni plating and Au plating to obtain an evaluation substrate.

  Next, an evaluation method for the evaluation board will be described.

  First, in order to investigate whether or not the penetrating conductor protrudes from the surface of the insulating substrate due to a defective binder, the penetrating conductor formed on the surface glass ceramic insulating layer was observed with a 20 × optical microscope. Quantity was measured. Further, using a three-dimensional measuring machine, the distance from the edge portion of the through conductor to the longest portion at the center of the through conductor was measured as a protrusion amount, and a protrusion having a protrusion amount of 5 μm or more was regarded as defective. As for the judgment, with respect to 100 evaluation boards, the number of protrusions exceeding 5 μm is judged to be defective when one of the evaluation boards is one, and the case where the occurrence rate exceeds 0% is judged as NG. did. The results are shown in Table 2.

  Then, in order to examine whether or not the through conductors protrude from the surface of the insulating base due to mismatching of the sintering behavior between the paste for through conductors and the glass ceramic green sheet, 10 points per evaluation board with a three-dimensional measuring machine The amount of protrusion was measured. In the measurement, any two adjacent through conductors were selected, and the distance from the surface of the insulating substrate located between the two through conductors to the line segment connecting the vertices of the two through conductors was defined as the protrusion amount. This measurement method is a measurement method in the case where the through conductor protrudes from the surface of the insulating substrate. However, even when the through conductor is depressed, the measurement is performed with the same idea, and the value is displayed as a minus value. As a judgment, a case where the absolute value of the protrusion amount exceeds 5 μm was judged as NG. Also, in the case where the protrusion of the penetrating conductor from the surface of the insulating base exceeds 50% due to the above-mentioned binder failure, it is difficult to measure the protrusion of the penetrating conductor from the surface of the insulating base due to mismatch of the sintering behavior. The measurement was stopped. The results are shown in Table 2.

  Furthermore, in order to confirm the amount of crystals precipitated from the glass added to the first and second through conductor pastes, the peak intensity measurement by X-ray diffraction and Rietveld analysis were used, and other than copper contained in the through conductors. The amount of crystal with respect to this portion was determined as the crystallinity. The results are shown in Table 2.

  As is apparent from Table 2, sample No. which is a sample outside the scope of the present invention. 5 and sample no. 13 is a paste obtained by adding only non-crystalline glass to the first and second through conductor pastes, but these samples are shaped as if the through conductors were partially exploded due to defective debinding. Protruded from the surface. In addition, since there were too many protrusions by this debindering defect, the protrusion by the mismatch of a sintering behavior was not able to be measured.

  In addition, sample No. which is a sample outside the scope of the present invention. 6 to 8 and 14 to 16 are obtained by adding crystalline glass and amorphous glass to both the first through conductor paste and the second through conductor paste, but compared to the first through conductor paste. Therefore, the amount of crystalline glass contained in the second through-conductor paste is not large, so that the crystallinity of the first through-conductor and the second through-conductor is the same or higher than that of the first through-conductor. The crystallinity of the second through conductor is low. In these samples, the penetrating conductor protruded from the surface of the insulating substrate due to the debinding failure.

  On the other hand, sample No. which is a sample within the scope of the present invention. For 1-4, 9-12, 17, and 18, the amount of crystalline glass contained in the second through-conductor paste is larger than that in the first through-conductor paste, and the first through-conductor is larger than the first through-conductor. The through-conductor of No. 2 has a high crystallinity. In these samples, the protrusion of the penetrating conductor from the surface of the insulating substrate due to a bad debinding is suppressed, and the protrusion due to mismatching of the sintering behavior can be suppressed to less than 5 μm, and the flatness is excellent. It was.

It is a schematic sectional drawing of one Embodiment of the wiring board of this invention. It is a schematic sectional drawing of the wiring board as a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Insulation base | substrate 1a-1i Glass ceramic insulation layer 2 Wiring layer 31 1st penetration conductor 32 2nd penetration conductor

Claims (2)

An insulating substrate formed by laminating three or more glass ceramic insulating layers, a wiring layer formed on and inside the insulating substrate, and a first through conductor formed in the glass ceramic insulating layer constituting the inner layer And a wiring substrate comprising a second through conductor formed on the glass ceramic insulating layer constituting the surface layer and directly connected to the first through conductor,
The first penetrating conductor and the second penetrating conductor contain the same amount of the same metal as a main component and also contain glass and precipitated crystals, and the amount of the precipitated crystals contained in the second penetrating conductor is A wiring board characterized by being larger than the amount of the precipitated crystal contained in the first through conductor. A through-hole is formed, and the through-hole is filled with a first through-conductor paste containing glass powder that does not substantially crystallize after firing, glass powder that partially crystallizes after firing, and metal powder . Producing a glass ceramic green sheet of
A through-hole is formed, and the through-hole includes a glass powder that does not substantially crystallize after firing, a glass powder that partially crystallizes after firing, and the same amount of metal powder as the first through-conductor paste , Producing a second glass ceramic green sheet filled with a second through conductor paste in which the amount of the glass powder that is partially crystallized is larger than that of the first through conductor paste;
The first glass ceramic green sheet is disposed in an inner layer and the second glass ceramic green sheet is disposed in a surface layer so that the first through-conductor paste and the second through-conductor paste are directly Producing a laminated body laminated so as to be connected;
And a step of firing the laminated body.

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