JP2005268414A - Multilayer ceramic substrate and manufacturing method thereof - Google Patents

Abstract

In a multilayer ceramic substrate obtained by laminating ceramic green sheets in a multilayer, thermocompression bonding, and firing integration, conductor patterns printed on each layer and interlayer displacement of VIA holes cause poor characteristics. . The method of grasping the amount of interlayer displacement requires a special apparatus such as an X-ray apparatus, and a method for manufacturing a multilayer ceramic substrate capable of detecting interlayer displacement by a simple method is required.
A green sheet laminate in which a detection mark pattern is provided on at least two ceramic green sheets, a plurality of ceramic green sheets are aligned and laminated by a guide pin, and then integrated by thermocompression bonding. Interleaving is detected by cutting at the detection mark pattern position and detecting the position of the detection mark pattern cross section exposed on the cut surface.
[Selection] Figure 1

Description

  The present invention relates to a method for manufacturing a multilayer ceramic substrate and a multilayer ceramic substrate manufactured by the manufacturing method, and in particular, a multilayer ceramic substrate in which a plurality of ceramic green sheets are laminated and then integrated by thermocompression bonding and firing. The present invention relates to a method for manufacturing a multilayer ceramic substrate including a step of detecting an interlayer shift of a ceramic green sheet by a simple method, and a multilayer ceramic substrate manufactured by the method.

  The multilayer ceramic substrate includes a step of forming a VIA hole in several to several tens of ceramic green sheets (hereinafter referred to as “green sheets”), a pattern forming step of forming a predetermined conductor pattern, Lamination process for laminating green sheets while aligning them, thermocompression process for fusing the green sheet polymer by thermocompression and integrating each other's green sheets, and sintering process for sintering the integrated green sheets It is manufactured by going through.

  Here, each process has a manufacturing variation. For example, a printing position accuracy varies in the pattern forming process, and a stacking position shift occurs between the stacked layers in the stacking process. Further, misalignment due to thermocompression occurs in the thermocompression bonding process, and misalignment occurs between the layers due to shrinkage in the sintering process. As a result of accumulating these manufacturing variations, the multilayer ceramic substrate has an interlayer shift.

  As a method for detecting the stacking deviation of the multilayer substrate, in the multilayer substrate formed by stacking two or more substrates each having a rectangular opening having a different size and an inner lead protruding from the periphery thereof, Detection marks along a diagonal line of the opening are formed with a predetermined width in at least two corners of the four rectangular corners of the rectangular opening, and the detection mark is detected. Thus, a method for detecting misalignment is shown (for example, see Patent Document 1).

JP-A-6-302716

  However, in the method of providing an opening and detecting the interlayer displacement of the multilayer ceramic substrate by the detection mark, there is a problem that the layer capable of detecting the interlayer displacement is limited to the layer having the opening. In addition, in order to detect an interlayer shift of all the stacked layers, it is necessary to provide a step shift of the substrate surface in all layers. As a result, a large area is required in the multilayer ceramic substrate for detecting the interlayer shift. There is a problem. Further, there is a problem that a layer in which an interlayer shift can be detected is limited to a layer having an opening with respect to a conductor (hereinafter referred to as “VIA conductor”) in which a conductor paste is filled in a VIA hole.

  For this reason, conventionally, it has been necessary to detect a conductor pattern of a multilayer ceramic substrate and an interlayer displacement of a VIA conductor using a special apparatus such as an X-ray apparatus.

  The present invention provides a method for manufacturing a multilayer ceramic substrate using a detection method capable of easily and accurately detecting a conductor pattern of a multilayer ceramic substrate and an interlayer displacement of a VIA conductor, and a multilayer ceramic substrate manufactured by the method. Objective.

  In the method for manufacturing a multilayer ceramic substrate according to the present invention, a plurality of green sheets are provided with alignment reference holes, and at least two or more green sheets for detecting interlayer displacement are provided with detection marks, and the alignment reference holes are provided. Is used as a reference, green sheets are laminated using a guide pin, the laminated body is cut at a position where the cross section of the detection mark is exposed to the cut surface, and the cross section of the detection mark on the cut surface is detected.

  As described above, according to the present invention, the detection mark cross section is detected on the cut surface of the laminate, and the interlayer shift between the substrates is detected based on the position of the detection mark cross section, thereby simplifying the interlayer shift of the multilayer ceramic substrate. And it can detect correctly.

Embodiment 1 FIG.
In recent years, multilayer ceramic substrates have come to be used as circuit substrates for high-frequency signals having a signal frequency of several tens of GHz. In applications where the signal frequency is several tens of GHz band, the conductor pattern width and the diameter of the VIA conductor are required to be 150 μm or less, and the conductor pattern is required to be made thinner or thinner. On the other hand, the VIA conductor also functions as a waveguide that shields external high-frequency signals that are noise. Since a large number of VIA conductors are formed in the substrate for the purpose of this shield, the density of the VIA conductors has increased, and as a result, the pitch between the VIAs has been narrowed.

  Interlayer misalignment of the multilayer ceramic substrate is a cause of product defects in the thinning of conductor patterns and the reduction in diameter and pitch of VIA conductors. For example, there are problems such as failure of connection between the conductor pattern and the VIA conductor and deterioration of the waveform of the high-frequency signal. The allowable value of interlayer displacement is about ± 0.05% (approx. +50 μm at the center allocation of 200 mm square substrate) or less in applications of several tens of GHz, and it is manufactured stably while satisfying the above-mentioned allowable value of interlayer displacement. It is difficult to do. In addition, the number of stacked layers is increased from the conventional level, and an interlayer shift is easily caused by increasing the number of stacked layers.

  Thus, in the production of a multilayer ceramic substrate for high-frequency signal applications, it is necessary to establish a method for accurately detecting inter-layer displacement. Further, in the product inspection process, an inspection method capable of instantaneously determining whether or not the interlayer displacement is within an allowable value is required.

Hereinafter, Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1 is a manufacturing flow of a multilayer ceramic substrate according to the first embodiment.
First, a green sheet prepared by a doctor blade method using a ceramic material containing a glass component, an organic binder, and a plasticizer is prepared, and a reference hole for alignment is provided by a punching method using a mold (step 101). Using the alignment reference hole as a position reference, the conductor paste is screen-printed through a mesh screen to form a product conductor pattern and an interlayer displacement detection mark pattern on each green sheet (step 102). Thereafter, the green sheet is laminated using a guide pin with reference to the alignment reference hole (103 laminating step), and the laminated green sheet is thermocompression-bonded to melt and integrate the green sheet polymer. A green sheet laminate is obtained (104 thermocompression bonding step).

  Here, it is estimated that the interlayer displacement is likely to occur in the thermocompression bonding process, and the interlayer displacement is detected after the 104 thermocompression bonding process. Therefore, the green sheet laminate is cut at the detection mark position formed in step 102 (step 105). The cross section of the mark pattern for detecting the interlayer displacement is exposed on the cut surface of the cut green sheet laminate. By detecting the position of the detection mark pattern cross-section, an interlayer shift is detected (step 106). Next, a multilayer ceramic substrate is formed by sintering the green sheet laminate in a temperature-controlled sintering furnace (107 sintering step). In the case where multiple faces are provided so that a plurality of products can be obtained from a single multilayer ceramic substrate, the product is cut into individual pieces by cutting at the product outline position (step 108).

Next, with reference to FIGS. 2 to 3, the step of detecting the interlayer shift (step 106), which is a feature of the first embodiment, will be described.
FIG. 2 is a perspective view of the green sheet laminate 1 after the thermocompression bonding (step 104). The green sheet laminate 1 is formed by laminating five green sheets 11, 12, 13, 14, and 15 having a length of 200 mm, a width of 200 mm, and a thickness of about 0.1 mm. In the first layer green sheet 11, the conductor pattern 3 and the mark pattern 2 for detecting the interlayer displacement are formed in advance by screen printing using the positioning reference hole 7 as a position reference in the step 102. Conductor patterns and interlayer misalignment detection mark patterns are also formed on the second layer green sheet 12 to the fifth layer green sheet 15, respectively, but are not shown in FIG. Here, the mark pattern for detecting the interlayer displacement is formed at the same coordinates in each layer of the first layer green sheet 11 to the fifth layer green sheet 15.
The mark pattern 2 has a width of about 0.15 mm and a length of 0.2 mm so that the mark pattern 2 can be cut at the mark pattern position even if there is an interlayer shift between the green sheets 11 to 15 by the 102 printing process, the 103 laminating process, and the 104 thermocompression bonding process. The shape was a rectangle having a size of about 6 mm.

FIG. 3 is a cross-sectional view of the green sheet laminate 1 when cut at the AA position shown in FIG. 2, and reference numerals 21 to 25 denote cross-section detection mark pattern cross sections exposed on the cross section of the green sheet laminate 1.
In FIG. 3, for example, the third layer green is measured by measuring the positional deviation amount X between the end of the mark pattern cross section 23 formed on the third layer green sheet 13 and the end of the mark pattern cross section 24 formed on the fourth green sheet 14. Interlayer displacement between the sheet 13 and the fourth layer green sheet 14 can be detected. Here, the amount of positional deviation between the mark pattern 23 and the mark pattern 24 is measured. However, by measuring the combination of other mark patterns, the interlayer deviation of all layers can be detected.

  As described above, the mark pattern cross section of each layer exposed when the green sheet laminate 1 is cut at a position including the mark pattern is detected, and the misalignment of the multilayer ceramic substrate is detected by detecting the misalignment. be able to. According to this method, there is no need to open an opening in the green sheet, and it is possible to detect an interlayer shift of all layers constituting the multilayer ceramic substrate by a simple method.

  Further, in the method of detecting the mark pattern from the upper surface, the mark pattern must be formed in each layer while changing the opening area. Therefore, as the number of stacks increases, the ratio of the mark area for detecting the interlayer displacement to the substrate area increases. . In the present invention, since the mark pattern is provided at the same XY coordinate position in each layer and the mark position is overlapped, there is an effect that the mark area for detecting the interlayer displacement is constant without depending on the number of layers.

  In the first embodiment, for example, the mark pattern is a rectangle having a width of about 0.15 mm and a length of about 0.6 mm. However, the mark pattern is detected on the cross section of the green sheet laminate 1 after being cut by a cutting machine. It should be as large as possible. Moreover, the shape may be a square or an ellipse, and the shape should just be detectable in the cross section of the green sheet laminated body 1. FIG.

  In the first embodiment, the mark pattern is provided at the same coordinate in each layer, but may be provided at a position shifted by a predetermined dimension in each layer.

  In the first embodiment, the number of stacked layers is five. However, according to the present invention, an interlayer shift can be detected regardless of the number of stacked layers.

  Further, the mark pattern for detecting the interlayer shift may be provided in a part of the product or may be provided outside the product.

  In the first embodiment, the green sheet laminate is sintered after detecting the interlayer displacement. However, the detection mark portion may be cut after the green sheet laminate is sintered to detect the interlayer displacement. Good. Thereby, there is an effect that the interlayer displacement after the 107 sintering step of sintering the green sheet laminate can be detected.

Embodiment 2. FIG.
A second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a manufacturing flow of the multilayer ceramic substrate according to the second embodiment.
First, green sheets are prepared for stacking, and a reference hole for alignment is provided by a punching method using a mold (step 301). Similarly, VIA holes for products and VIA holes for marks used in products are formed by punching with a mold (step 302), and conductor paste is filled in each VIA hole by squeezing through a metal mask. A conductor and a mark VIA conductor are produced (step 303). Next, a conductor pattern is formed by screen printing using the alignment reference hole provided in step 301 as a reference (step 304). Thereafter, the green sheets are laminated using a guide pin with the alignment reference hole as a reference (305 lamination step), and the laminated green sheets are thermocompression-bonded to obtain a green sheet laminate (306 thermocompression step). ). Next, the mark VIA conductor produced in step 303 is cut by a cutting machine (step 307). The cross section of the mark VIA conductor is exposed on the cut surface, and the position of the VIA conductor cross section is measured to detect an interlayer shift of each layer (step 308). Subsequently, sintering is performed (step 309). When multiple faces are obtained so that a plurality of products can be obtained from a single multilayer ceramic substrate, cutting is performed at the product outer shape and singulation is performed (step 310).

Next, with reference to FIGS. 5 to 6, the process of detecting the interlayer shift (step 308), which is a feature of the second embodiment, will be described. Here, in FIGS. 5 to 6, the same reference numerals as those in the other drawings are the same or equivalent.
FIG. 5 is a perspective view of the green sheet laminate 1 after the 306 thermocompression bonding process. The green sheet laminate 1 includes five green sheets 11, 12 having a length of about 200 mm, a width of 200 mm, and a thickness of about 0.1 mm. 13, 14, and 15 are laminated and formed. The second layer green sheet 12 to the fifth layer green sheet 15 are also provided with conductor patterns and interlayer displacement detection mark VIA conductors, respectively, but are not shown in FIG. Here, the mark VIA conductor for detecting the interlayer shift is formed at the same coordinates in each layer of the first layer green sheet 11 to the fifth layer green sheet 15.
The size of the product VIA conductor 4 is φ0.15 mm, and the mark VIA 5 can be cut at the mark VIA position even if there is an interlayer shift between the green sheets 11 to 15 by the printing process, the laminating process, and the thermocompression bonding process. In addition, a long hole shape having a width of 0.15 mm and a length of 0.6 mm was used.

FIG. 6 is a view showing a cross section of the green sheet laminate 1 when cut along a plane including AA shown in FIG. 5. Reference numerals 51 to 55 denote marks for detecting an interlayer shift exposed on the cross section of the laminate 1. It is a cross section of a VIA conductor for use.
Here, for example, by measuring the positional deviation amount X between the center line of the mark VIA conductor 53 formed on the green sheet 13 and the center line of the mark VIA conductor 55 on the green sheet 15, the green sheet 13 and the green sheet 15 are measured. Can be detected. Here, the amount of misalignment between the mark VIA conductor 53 and the mark VIA conductor 55 is measured. However, by measuring combinations of other mark VIA holes, it is possible to detect interlayer misalignment of all layers. it can.

  As described above, by detecting the amount of misalignment of the mark VIA conductor exposed when the green sheet laminate 1 is cut, it is possible to easily detect the interlayer displacement of the multilayer ceramic substrate. In the second embodiment, it is possible to accurately and easily measure the positional deviation of the product VIA hole by detecting the positional deviation of the mark VIA hole drilled in the same process as the product VIA hole. Have.

  Further, according to the manufacturing method shown in the second embodiment, there is no need for an opening in the green sheet for detecting the interlayer shift, and it is possible to detect the interlayer shift of all layers constituting the multilayer ceramic substrate by a simple process. Have.

  In the second embodiment, the center position of the cross section of the mark VIA conductor is detected, but the end position of the cross section of the mark VIA conductor may be detected.

Embodiment 3 FIG.
In Embodiment 3 of the present invention, the mark pattern shown in Example 1 and the mark VIA hole shown in Example 2 are provided at the same location.
The method for detecting the interlayer shift, which is a feature of the third embodiment, will be described with reference to FIGS. 7 to 8, the same reference numerals as those in the other drawings are the same or equivalent.

FIG. 7 is a perspective view of the green sheet laminate 1 according to Embodiment 3, wherein 4 is a product VIA conductor, 5 is a mark VIA conductor, and 2 is a mark pattern. In the third embodiment, the mark VIA hole 5 and the mark pattern 2 are provided at the same location.
8 is a cross-sectional view taken along a plane including AA in FIG.
In the example of FIG. 8, the mark pattern 21 has a displacement X1 with respect to the VIA conductor 51. Since the mark pattern 21 is printed on the basis of the alignment reference hole 7 formed at the same time as the VIA conductor 51, it can be seen from this result that there is a high possibility of causing a positional shift in the printing process. Further, in the VIA conductor 51 and the VIA conductor 52, the positional deviation X2 of the VIA conductor 51 with respect to the VIA conductor 52 is generated in the left direction. From this result, it is presumed that there is a high possibility that the first layer green sheet 11 is displaced in the left direction with respect to the second layer green sheet 12 in the lamination process or the thermocompression bonding process, and the investigation range is narrowed down. Cause investigation. Thus, providing the mark VIA hole and the mark pattern at the same location has an effect of facilitating investigation of the cause of the interlayer displacement.

  In the third embodiment, the mark pattern and the mark VIA hole are in the same place, but both the mark pattern and the mark VIA hole are on the same side of the side cut by AA in FIG. Yes, if it can be confirmed at the same time.

Embodiment 4 FIG.
In the first to third embodiments, the number of mark patterns for detecting the interlayer shift is only one. However, by providing a plurality of mark patterns, the cause of the interlayer shift can be easily estimated.
FIG. 9 is a perspective view of the green sheet laminate 1 according to the fourth embodiment. The same reference numerals as those in the other drawings are the same or the same equivalents.

  In FIG. 9, 2 a, 2 b, 2 c, and 2 d are rectangular mark patterns having a width of 0.15 mm and a length of 0.6 mm, and are provided on the four sides of the first layer green sheet 11. The mark patterns are formed at the same coordinates in the green sheets 11 to 15, but FIG. 9 does not illustrate other than the first layer green sheet. Reference numeral 3 denotes a conductor pattern used for a product. Here, it is assumed that four products are obtained from the green sheet laminate 1.

The mark patterns 2a, 2b, 2c, and 2d are cut along the planes including AA, BB, CC, and DD shown in FIG. 9, and the interlayer displacement of each layer is detected from the mark pattern exposed on the cut plane. To do.
As an example of the analysis of the interlayer displacement, the first layer green sheet and the second layer green sheet obtained from the mark patterns of the AA cut surface, the BB cut surface, the CC cut surface, and the DD cut surface It is assumed that the directions of the interlayer displacement all indicate that the first layer green sheet is displaced in the right direction from the second layer green sheet. From this result, it can be seen that the first layer green sheet is shifted in the counterclockwise rotation direction with respect to the second layer green sheet.

As in the above example, by providing marks on the four sides of the green sheet, it is possible to detect a shift in the rotational direction as well as the direction of the interlayer shift.
Although four mark patterns are provided in FIG. 9, the same effect can be obtained even with the two mark patterns 2a and 2b on the diagonal as shown in FIG.

Embodiment 5 FIG.
In the fourth embodiment, the mark pattern by screen printing is set, but the same effect can be obtained by using the mark VIA hole instead of the mark pattern.

Embodiment 6 FIG.
A sixth embodiment of the present invention will be described with reference to FIG. FIG. 11 is a view showing a cut surface of a green sheet laminate on which a mark pattern is formed.
In the first embodiment, the mark patterns 21 to 25 for confirming the interlayer shift are formed at the same coordinates in each layer as shown in FIG. They are formed so as to overlap with an allowable value L1. For example, when the interlayer deviation allowable value L1 is 50 μm, the mark patterns of the respective layers are formed so as to be shifted by 50 μm and overlap. Thereby, it is possible to visually confirm whether or not the interlayer displacement between the adjacent upper and lower layers is within the allowable value, and it is possible to easily determine whether the interlayer displacement is good or bad.

Instead of the mark pattern, a mark VIA conductor formed so as to be shifted and overlapped by an allowable deviation L1 may be used, or the mark pattern and the mark VIA hole may be used in combination.
In addition, a mark pattern in which the direction of shifting is reversed or a mark pattern formed at the same coordinates shown in the first embodiment may be added, and there is an effect that it is possible to easily determine whether or not the interlayer deviation is good visually.

Embodiment 7 FIG.
A seventh embodiment of the present invention will be described with reference to FIG. FIG. 12 is a view showing a cut surface of a green sheet laminate on which a mark pattern is formed.
In the sixth embodiment, the mark pattern for confirming the interlayer shift is formed so as to be shifted by the interlayer shift tolerance L1, but in the seventh embodiment, the width dimension of the mark pattern formed on the green sheet of each layer is changed, The width dimension of the mark pattern of the nth layer is set to the width dimension of the (n−1) th layer + 2 × L1. Here, L1 is an allowable value of interlayer displacement. By arranging the portion of the mark pattern of the nth layer that protrudes from the mark pattern of the (n−1) th layer to be L1 on both sides, there is an effect that it is possible to easily judge whether or not the layer shift is good.

  Although the mark pattern is used in the seventh embodiment, a mark VIA hole in which the hole diameter is changed may be used instead of the mark pattern, or the mark pattern and the mark VIA hole may be used in combination.

3 is a flow chart for manufacturing a multilayer ceramic substrate according to the first embodiment. 2 is a perspective view of a green sheet laminate according to Embodiment 1. FIG. 2 is a cross-sectional view of a green sheet laminate according to Embodiment 1. FIG. 6 is a manufacturing flow of the multilayer ceramic substrate according to the second embodiment. 6 is a perspective view of a green sheet laminate according to Embodiment 2. FIG. 6 is a cross-sectional view of a green sheet laminate according to Embodiment 2. FIG. 6 is a perspective view of a green sheet laminate according to Embodiment 3. FIG. 6 is a cross-sectional view of a green sheet laminate according to Embodiment 3. FIG. FIG. 6 is a perspective view of a green sheet laminate according to a fourth embodiment. It is a perspective view of the green sheet laminated body by Embodiment 4. It is sectional drawing of the green sheet laminated body by Embodiment 6. FIG. It is sectional drawing of the green sheet laminated body by Embodiment 7. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Green sheet laminated body, 2 Mark pattern, 3 Conductor pattern, 7 Reference hole for alignment, 11 1st layer green sheet, 12 2nd layer green sheet, 13 3rd layer green sheet, 14 4th layer green sheet, 15 5th layer green sheet, 21 1st layer mark pattern, 22 2nd layer mark pattern, 23 3rd layer mark pattern, 24 4th layer mark pattern, 25 5th layer mark pattern.

Claims (11)

Two or more substrates provided with a reference hole for alignment and provided with detection marks using the reference hole for alignment as a position reference are aligned and stacked, and the cross section of the detection mark is cut to a cut surface. A first step of cutting at an exposed position;
A second step of detecting an interlayer shift between the substrates based on the position of the cross section of the detection mark on the cut surface cut in the first step;
A method for producing a multilayer ceramic substrate, comprising: 2. The method for manufacturing a multilayer ceramic substrate according to claim 1, wherein the detection mark in the first step is a conductor pattern. 2. The method of manufacturing a multilayer ceramic substrate according to claim 1, wherein the detection mark in the first step is a VIA conductor in which a VIA hole is filled with a conductive paste. 2. The method for manufacturing a multilayer ceramic substrate according to claim 1, wherein the detection mark in the first step is composed of a conductor pattern and a VIA conductor in which a VIA hole is filled with a conductor paste. A multilayer ceramic substrate manufactured by the manufacturing method according to claim 1. 6. The multilayer ceramic substrate according to claim 5, wherein the detection mark is a conductor pattern. 6. The multilayer ceramic substrate according to claim 5, wherein the detection mark is a VIA conductor in which a VIA hole is filled with a conductive paste. 6. The multilayer ceramic substrate according to claim 5, wherein the detection mark is composed of a conductor pattern and a VIA conductor having a VIA hole filled with a conductor paste. 9. The multilayer ceramic substrate according to claim 7, wherein the detection marks are formed with substantially the same width. 9. The multilayer ceramic substrate according to claim 7, wherein the detection mark is formed with a different width for each substrate. 6. The multilayer ceramic substrate according to claim 5, wherein the detection mark is provided on at least two sides of four sides of the rectangular substrate.

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