JP3076215B2 - Ceramic multilayer substrate and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic multilayer substrate having improved alignment accuracy when a post-process such as printing is performed on a fired substrate, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, in a ceramic multilayer substrate manufactured by laminating and firing a plurality of green sheets, there is a co-firing type in which a conductor pattern on the substrate surface is fired simultaneously with a green sheet laminate. There is also a post-installation type in which a conductor, a resistor, or the like is printed and fired on the substrate surface, or an electrical quality inspection such as a trimming of the resistor or the like or a short-open inspection is performed in a post-process after the firing of the green sheet laminate. In this post-installation type, when performing a post-process such as printing on the substrate surface, it is necessary to accurately align the substrate, and therefore, generally, as shown in FIG. The edge is used as a reference for positioning, and this is brought into contact with three positioning pins 3 on the positioning table 2 to position the substrate.

[0003]

As shown in FIG. 6, when a conductor pattern 4 is printed on a fired substrate 1, a via 6 and a conductor for electrically connecting each layer (green sheet 5) of the substrate 1 up and down are formed. It is necessary that the pattern 4 overlaps exactly as shown in FIG. However, since the green sheet 5 before firing is soft and plastic, a lamination misalignment occurs during lamination as shown in (b), or an outer peripheral cutting line (snap line) as shown in (c) is formed. It may be shifted. Even if the snap lines are not shifted, burrs 7 may be formed when cutting with the snap lines after firing, as shown in FIG. In any of these cases (b) to (d), a normal case (a)
When the substrate is aligned, the distance B between the alignment pin 3 (the edge of the substrate) and the via 6 is shifted, so that the position A is a fixed distance A from the alignment pin (the edge of the substrate). The conductor pattern 4 to be printed is printed at a position shifted from the via 6, resulting in a defective connection.

In particular, as small and high-density mounting has progressed in recent years, higher alignment accuracy is required. At present, the position of a substrate is recognized by image processing using a high-precision CCD camera to perform alignment. Although the apparatus has been put to practical use, this apparatus is very expensive and has a drawback that causes a cost increase.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and accordingly, it is an object of the present invention to accurately align a substrate using alignment pins, and to improve quality and yield. An object of the present invention is to provide a ceramic multilayer substrate which can be achieved and a method for manufacturing the same.

[0006]

In order to achieve the above object, a first object of the present invention is to provide a ceramic multilayer substrate having a wiring on a surface, which is formed by laminating and firing a plurality of green sheets. At the edge, fit the alignment pin
A plurality of notches for surface alignment are formed, and the notches for each surface alignment are formed in a stepped shape in which the other layer is more deeply recessed than the surface layer.

Further, when the present invention is applied to a ceramic multilayer substrate having double-sided wiring, a plurality of notches for aligning the front surface and a plurality of notches for aligning the back surface are provided at the edge of the substrate. And a notch for each surface alignment,
If the other layer is formed in a stepped shape in which the other layer is deeper than the recess in the surface layer, the notch for each back surface alignment is formed in a stepped shape in which the other layer is more deeply recessed than the backside layer. good.

In the case of manufacturing such a ceramic multi-layer substrate, a hole for forming each of the notches is formed simultaneously with forming a via hole or the like in the green sheet. The depth of the notch forming hole of the green sheet laminated on the front surface layer or the back surface layer from the cutting line to the inside of the substrate is smaller than the notch forming hole of the green sheet laminated on another layer. After laminating or firing the green sheet, the laminate is cut so as to divide the holes, thereby forming the respective cutouts, and forming a plurality of cutouts of the fired substrate into a plurality of cutouts. A post-process such as printing may be performed by aligning the substrate with the alignment pins.

[0009]

According to the first aspect of the present invention, at the time of positioning the substrate, the plurality of cutouts for aligning the surface formed at the edge of the substrate are fitted to the positioning pins, thereby positioning the substrate. I do. At this time, the notch for each surface alignment is formed in a stepped shape in which the other layer is deeper than the depression in the surface layer, so that the inner edge of the notch in the surface layer of the substrate is positioned at the time of substrate alignment. Being always in contact with the dowel pin, it is possible to always perform alignment with reference to the inner edge of the cutout of the surface layer, without being affected by the above-mentioned lamination displacement, displacement of the outer peripheral cutting line (snap line) and burrs. Only Furthermore, if the notch portion is formed simultaneously with the formation of the via hole or the like in the green sheet, the via hole of the surface layer and the alignment pin (notch portion), which are the most necessary positional accuracy in the post-process alignment after firing the substrate. And the position accuracy between them can be accurately secured, and the number of processes does not need to be increased.

In the case of a ceramic multilayer substrate having double-sided wiring, a notch for aligning the front surface is provided at the edge of the substrate, and a notch for aligning the rear surface is formed in an opposite relationship to the front and back. When printing or the like is performed on the front surface of the substrate by forming a notch portion of the above, the notch portion for aligning the front surface is fitted to the positioning pin, and printing or the like is performed on the back surface of the substrate. In this case, the notch for positioning the back surface is fitted to the positioning pin. Since the notch for alignment of the back surface has a stepped shape in which the other layer is more deeply recessed than the recess in the back surface layer,
At the time of back surface alignment, the inner edge of the notch of the back layer of the substrate always comes into contact with the alignment pin, and accurate positioning can always be performed based on the notch of the back layer.

In the case of manufacturing the above-described ceramic multi-layer substrate, in the manufacturing method according to the third aspect, holes for forming the respective notches are formed at the same time when the via holes are formed in the green sheet. The via hole and the hole for forming the cutout are always formed in a fixed positional relationship. At this time, the depth from the cutting line to the inside of the substrate is smaller than the cutout forming hole of the green sheet laminated on the other layer, the cutout forming hole of the green sheet laminated on the surface layer or the backside layer. When these green sheets are laminated, a small hole for forming a cutout in the surface layer or the rear surface layer is made to overlap with a large hole in another layer. Then, after laminating or firing the green sheets, the cutout is cut so as to divide the holes, thereby forming each notch. At this time, when the substrate is cut after firing, a snap line (cutting line) passing through a hole for forming a notch is press-formed in the green sheet laminate before firing, and after the firing, the snap line is cut along the snap line. Good. The ceramic multilayer substrate manufactured in this manner has the configuration of claim 1 or 2 described above, and the notch of the substrate is fitted to the alignment pin, thereby accurately aligning the substrate and performing printing or the like. Perform the process.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. First, the configuration of a ceramic multilayer substrate (hereinafter, abbreviated as “substrate”) 11 will be described with reference to FIGS. 1 and 2. As shown in FIG. 1, a total of three notch portions 12 for surface alignment are formed at the edges of two adjacent sides of the substrate 11, and the notches for surface alignment are formed at the remaining two edges. Notch 1 for backside positioning, which has the opposite relationship to part 12
3 are formed in total. The notch 12 for surface alignment is, for example, 0.1 m in the other layer than the recess in the surface layer.
m.
, The inner edge of the notch 12 of the surface layer always comes into contact with the positioning pin 14.
On the other hand, the notch 13 for alignment of the back surface is formed in a stepped shape in which the other layer is deeper than the recess of the back layer by, for example, 0.1 mm or more. When aligning the back surface, the inner edge of the notch 13 of the back layer is positioned. The contact pin 14 is always in contact with the dowel pin 14.

As shown in FIG. 2A, the substrate 11 is manufactured by laminating and firing a plurality of green sheets 15 as in the prior art. The via hole 16 is formed by punching with a punching machine or the like, and the via hole 16 is filled with a conductive material to form a via 17. The inner layer of the substrate 11 is provided with an inner layer pattern 18 (see FIG. 4) such as a conductor or a dielectric printed on the green sheet 15 before lamination. After the substrate is baked, a conductor pattern 19 (only the conductor of the surface layer is shown in FIG.
The conductor of the back layer is indicated by reference numeral “4” in FIG. 6) and printed and baked.
The notch 12 (or 13) at the position is
4.

Next, the substrate 11 having the above structure is fired at a low temperature (1.
FIG. 3 shows an example of a manufacturing method in the case of firing at 000 ° C. or less.
This will be described with reference to FIG. The method of producing the green sheet 15 used here is CaO—Al ₂ O ₃ —SiO ₂ —
B ₂ O ₃ based glass powder 60 wt% alumina powder 40
and a plasticizer (for example, DOP),
Binder (for example, acrylic resin), solvent (toluene,
(Xylene, alcohols) are added and sufficiently kneaded to prepare a slurry having a viscosity of 2000 to 40000 cps, and a 0.3 mm thick green sheet for low temperature firing is formed by a doctor blade method.

After that, the green sheet 15 is placed at a predetermined position on the green sheet 15 by using a punching die or a punching machine.
Many via holes 16 of about 1.00 mmφ, four guide holes 20 and six square holes 21 and 22 for forming notches
At the same time. Here, the guide hole 20 is
The guide sheet (not shown) is inserted into the guide hole 20 when the pattern is printed or laminated on the green sheet 15 at the four corners of the green sheet 15 to position the green sheet 15 of each layer. . Further, the square holes 21 and 22 for forming the cutout portions are located on the line 23 that is cut after lamination, and finally become the cutout portions 12 and 13. As shown in FIGS. 3A and 3D, the green sheet 15 serving as the front surface layer and the back surface layer has three small square holes 21 and three square holes 22 larger by 0.1 mm or more than the small square holes 21 respectively. The large and small square holes 22 and 21 have opposite positions in the front layer and the rear layer. As shown in FIGS. 3B and 3C, the green sheet 15 serving as the inner layer is formed with only six large square holes 22 in total. A total of six square holes 21 and 22 formed in each green sheet 15 are formed at the same position, and when the green sheets 15 are stacked, a through hole vertically penetrating with the square holes 21 and 22 is formed. In each of the front layer and the back layer, three small square holes 21 overlap the large square holes 22 of the other layers.

After the via holes 16, the guide holes 20, and the square holes 21 and 22 for forming the cutouts are simultaneously punched and formed in the green sheet 15 of each layer as described above, the green sheets are electrically connected between the layers. The via hole 16 of the sheet 15 is filled with an Ag-based conductor material. Thereafter, as shown in FIG. 4A, an inner layer pattern 18 is formed on each green sheet 15 of the inner layer and the back layer by using Ag, Ag-Pd,
After screen printing using a conductive material paste such as Ag-Pt or Ag-Pd-Pt, each green sheet 15 is printed.
Are laminated, for example, at a temperature of 80 to 150 ° C. and 50 ° C.
It is integrated by thermocompression bonding under the condition of ２５０250 kg / cm ² .
The positioning of the green sheet 15 at the time of printing and laminating the inner layer pattern 18 is performed by inserting guide pins (not shown) into the guide holes 20 at the four corners of the green sheet 15. The laminated body thermocompression-bonded as described above is cut along the cutting line 23. By this cutting, each of the square holes 21 and 22 is divided into notches 12 and 13. This laminate was placed in air for 90 hours using an electric continuous belt furnace.
By firing at 0 ° C. for 20 minutes, a ceramic multilayer substrate 11 is formed.

Thereafter, the conductor pattern 1 is formed on the surface of the substrate 11.
When printing 9, as shown in FIGS. 1 and 2, a notch 12 for surface alignment is fitted on an alignment pin 14 on an alignment table 25, and the substrate 11 is attached to the notch 12. Align with reference. In this case, the notch 12 for aligning the surface has a thickness of 0.1 m for the other layer than the recess of the surface layer.
Since it is a stepped shape that is deeply recessed by m or more, the inner edge of the notch 12 of the surface layer always comes into contact with the positioning pin 14 when fitted to the positioning pin 14. Even if the stacking shift, the shift of the cutting line 23, or the cut portion has burrs, these have no effect on the contact state between the inner edge of the cutout 12 of the surface layer and the positioning pin 14. This is not provided, and positioning based on the inner edge of the notch 12 of the surface layer can always be performed. Moreover, since the square holes 21 serving as the cutouts 12 are punched and formed at the same time when the via holes 16 and the like are formed in the green sheet 15, the vias 17 of the surface layer and the alignment pins 14 (the inner edges of the cutouts 12 of the surface layer) are formed.
A (see FIG. 2) can always be constant, and the via 1 of the surface layer which is most necessary for the alignment in the post-process after the substrate baking.
The alignment accuracy of No. 7 can be secured extremely accurately.

The conductor pattern 19 is formed on the surface of the substrate 11 accurately aligned in this manner by using an Au-based conductor.
Is printed and fired. On the other hand, when printing the conductor pattern 19 on the back surface of the substrate 11, the substrate 11 may be turned upside down, and the notch 13 for positioning the back surface may be fitted to the positioning pin 14 for positioning. In other words, the notch 13 for alignment of the back surface is, for example, 0.1.
Since the stepped shape is recessed by 1 mm or more, the inner edge of the cutout portion 13 of the backside layer of the substrate 11 always comes into contact with the positioning pin 14 at the time of backside alignment. And accurate positioning can be achieved.

The present inventors manufacture the substrate 11 by the manufacturing method described above, print and bake a conductor pattern 19 on the surface of the substrate 11, and obtain a defect occurrence rate due to a displacement between the conductor pattern 19 and the via 17. As a result of evaluating
As shown in (b), the conductor pattern 19 and the via 17
Are completely overlapped with each other, and the defect occurrence rate is 0%.
Met.

On the other hand, as a comparative example, a substrate in the form shown in FIG. 5 having no notches 12 and 13 for alignment was manufactured, and a conductor pattern was printed and fired on the surface of the substrate to form a conductor pattern, a via and a via. As a result of evaluation of the defect occurrence rate due to the positional deviation, the conductor pattern was considerably deviated from the via, and the defect occurrence rate was as high as 16%.

As is apparent from the above test results, according to the present embodiment, the notch 1 for positioning is formed at the edge of the substrate 11.
By forming the steps 2 and 13 in the form of steps, the alignment accuracy of the substrate 11 can be remarkably improved, and the requirements for quality improvement and yield improvement can be sufficiently satisfied. Moreover, since the positioning of the substrate 11 can be performed using the positioning pins 14, an expensive positioning device using a high-precision CCD camera or the like is not required for the positioning of the substrate 11, and a reduction in equipment cost is required. Can also be satisfied. Further, the notches 12 and 13 (square holes 21 and 22) for alignment are formed at the same time when the via holes 16 and the like are formed in the green sheet 15, so that the number of manufacturing steps is the same as the conventional one, and the manufacturing efficiency is also high. It does not have to fall.

By the way, the notches 12 and 13 for positioning are provided.
When the positioning hole is formed in the substrate 11 instead of the above, not only is the operation of inserting the positioning pin into the positioning hole from directly above than in the above-described embodiment complicated, but also when the positioning pin is inserted. There is a possibility that the periphery of the alignment hole may be chipped, which may cause a decrease in yield. In this regard, in the above-described embodiment, the notch 1 opened to the outside instead of the hole is used.
2 and 13, the fitting with the positioning pin 14 can be easily performed from the outside, and the possibility of the peripheral edges of the notches 12 and 13 being chipped is much smaller than that of the hole. I'm done.

In the above embodiment, the green sheet 15
Although the step of cutting the substrate 11 from the laminate is performed before firing, the present invention is not limited to this. The substrate 11 may be cut from the fired laminate as in the related art. Specifically, after laminating the green sheets 15, a snap line (cutting groove) is press-formed on the surface of the laminate, and the laminate is fired by firing. The substrate 11 is cut from the later laminated body.

In the above embodiment, the present invention is applied to a ceramic multilayer substrate having a double-sided wiring in which conductor patterns and the like are retrofitted on both sides of the substrate. May be
In this case, the notch 13 for back surface alignment may be eliminated from the above embodiment.

In the above embodiment, the present invention is applied to a ceramic multilayer substrate fired at a low temperature. However, it is needless to say that the present invention can be applied to a multilayer substrate formed of another ceramic material such as an alumina multilayer substrate. No. In addition, it goes without saying that the present invention can be implemented with various changes within a range not departing from the gist, such as the number, position, or shape of the alignment notches 12, 13 may be appropriately changed as necessary. No.

[0026]

As is apparent from the above description, according to the ceramic multi-layer substrate of the first aspect of the present invention, the notch for aligning the surface formed at the edge of the substrate is more than the notch of the surface layer. Since the other layers are deeply concave,
At the time of substrate alignment, the inner edge of the notch of the surface layer of the substrate always comes into contact with the alignment pin, and the alignment of the inner edge of the notch of the surface layer is always used as a reference for alignment. It is possible to perform high-precision positioning without being affected by the influence, and it is possible to satisfy requirements for quality improvement and yield improvement. In addition, the positioning of the substrate can be performed using the positioning pins.
It does not require an expensive alignment device using a D camera, etc.
It can also meet the demand for equipment cost reduction.

[0027] According to the second aspect of the present invention, at the edge of the substrate,
Since the notch for the front surface alignment and the notch for the back surface alignment having the opposite relationship to the front and back are formed, the post-process such as printing is performed on both the front and back surfaces of the substrate with high alignment accuracy. be able to.

Further, in the manufacturing method according to the third aspect, the holes for forming the notches are formed at the same time when the via holes are formed in the green sheet, so that the holes for forming the via holes and the notches are formed. Can always be formed in a fixed positional relationship, and the alignment accuracy of the via of the surface layer, which is the most necessary in the post-process alignment after the substrate baking, can be secured extremely accurately, and the number of manufacturing steps is greatly increased. Therefore, there is an advantage that the production efficiency does not decrease.

[Brief description of the drawings]

FIGS. 1A and 1B show an embodiment of the present invention, wherein FIG. 1A is a plan view of a ceramic multilayer substrate, and FIG. 1B is a longitudinal sectional view taken along line AA ′ of FIG.

FIG. 2A is an enlarged longitudinal sectional view of a main part showing a relationship between a notch and an alignment pin, and FIG. 2B is a plan view of the same.

FIG. 3 is a plan view showing a state after a punching step of a green sheet laminated on each layer.

FIG. 4 is a process diagram illustrating a process from a printing process to a firing process.

FIG. 5A is a plan view of a substrate for explaining a conventional method of aligning the substrate, and FIG. 5B is a side view of the same.

FIG. 6 is a diagram illustrating a cause of a displacement between a via and a conductor pattern.

[Explanation of symbols]

11 ... substrate, 12 ... notch for front surface alignment, 13 ... notch for rear surface alignment, 14 ... alignment pin, 15 ... green sheet, 16 ... via hole, 17 ... via, 19 ...
Conductor pattern, 20: guide hole, 21, 22, square hole, 2
3: Cutting line.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-27144 (JP, A) JP-A-5-283868 (JP, A) JP-A-59-181598 (JP, A) JP-A-2- 138786 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H05K 3/46 H05K 1/02

Claims (3)

(57) [Claims] 1. A ceramic multi-layer substrate having a wiring on a surface formed by laminating and firing a plurality of green sheets, a plurality of surface alignment notches for fitting alignment pins at an edge of the substrate. A ceramic multi-layer substrate, wherein each of the notch portions for surface alignment is formed in a stepped shape in which the other layer is deeper than the recess in the surface layer. 2. A double-sided ceramic multi-layer substrate formed by laminating and firing a plurality of green sheets, a plurality of notches for aligning the front surface and a plurality of notches for aligning the back surface are provided at the edge of the substrate. The notch for each surface alignment is formed in a stepped shape in which the other layer is more deeply recessed than the depression in the surface layer, and the notch for each back surface alignment is formed by a recess in the back layer. A ceramic multilayer substrate, wherein another layer is formed in a stepped shape with a deeper depression. 3. The method for manufacturing a ceramic multilayer substrate according to claim 1, wherein holes for forming the respective notches are formed simultaneously when forming via holes or the like in the green sheet, and The hole for forming the notch of the green sheet of the surface layer or the back layer is formed so that the depth from the cutting line toward the inside of the substrate is smaller than the hole for forming the notch of the green sheet laminated on another layer. After laminating or firing the green sheets, the laminate is cut so as to divide the holes, thereby forming the cutouts, and connecting the cutouts of the fired substrate to a plurality of alignment pins. A method of manufacturing a ceramic multilayer substrate, wherein the post-process such as printing is performed by aligning the substrate by fitting into the substrate.