JP2005347646A - Ceramic substrate and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ceramic substrate capable of preventing chipping at the end edge and also capable of surely dividing along a groove even at the intersection of dividing grooves. <P>SOLUTION: Each of dividing grooves (31 and 41) and (32, 42) contains a first groove part 51 and a second groove part 52. The first groove part 51 is a narrow groove positioned in the depth. The tip of the second groove part 52 continues to the first groove part 51, containing the part where a groove width W1 gradually expands toward one surface. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a ceramic substrate used for manufacturing various ceramic electronic components and a manufacturing method thereof.

When manufacturing various types of ceramic electronic components, a wafer-shaped ceramic substrate in which a large number of electronic component elements are arranged in a lattice shape is generally used. In the case of a multilayer ceramic electronic component, the ceramic substrate is multilayered, and circuit elements constituting the electronic component element, such as a conductor pattern, are arranged not only on the surface of the substrate but also between the layers.
As a method for manufacturing the above-mentioned wafer-like ceramic substrate, various methods are conventionally known. Basically, a conductor pattern to be a circuit element is formed on one surface of an unfired ceramic green sheet by means such as screen printing, and a plurality of the green sheets thus obtained are laminated, pressure-bonded, and pressed. A fired ceramic substrate is obtained.

  Next, after passing through a drying process, it is fired through a firing furnace. And after baking, a board | substrate is cut | disconnected and the single item of an electronic component element is taken out.

  In the firing step, the conductor pattern must be sintered simultaneously with the sintering of the unfired ceramic substrate itself. Therefore, in general, a ceramic material that can be sintered simultaneously with the conductor pattern is selected. Such a ceramic material is called a low temperature co-fired ceramic (hereinafter referred to as LTCC), and is generally composed of a composite material of a ceramic material and a glass material.

  By the way, the use of the wafer-like ceramic substrate is, of course, to ensure the mass productivity of the electronic component. However, as long as the wafer-like ceramic substrate is used, cutting for taking out the electronic component element as a single product at any stage. A split process must be performed. Cutting. As the execution timing of the division process, there are two cases, for example, when it is executed in an unfired stage and after firing, as adopted in the method of manufacturing a multilayer ceramic capacitor, and a ceramic substrate using LTCC Then, disconnect. The splitting process is often performed after firing.

  Cutting in this case. As a method of dividing, a method using a cutting tool such as a dicer is also known, but at the stage of an unfired ceramic substrate, a horizontal dividing groove (or a vertical dividing groove) is put on one or both sides and fired. Later, the so-called “chocolate break” method of folding along these dividing grooves is frequently used because it is simple.

  However, there has been a serious problem that chipping or the like occurs at the edge during or after the dividing operation and the product yield is significantly reduced. In particular, a ceramic substrate using LTCC is susceptible to this problem due to brittleness caused by material properties.

  In addition, with the recent miniaturization and higher functionality of electronic components, the chip substrate after the division has been promoted to be miniaturized and multi-layered, so that chipping or the like occurs at the edge, resulting in a significant decrease in product yield. This problem tends to increase more and more.

  Conventionally, various techniques have been proposed for the purpose of solving the above-described problems or problems similar thereto. For example, in Patent Document 1, the cut grooves on the front and back surfaces of the circuit board are inclined vertically with one end face facing up and down and vertically rising and falling, and the other end face facing front and back. A technique for forming a slanted cross-section in a letter shape and avoiding burrs during cutting is disclosed.

  In Patent Document 2, a dummy region in which vertical and horizontal dividing grooves formed in the product region are provided outside the product region, and the depth of the dividing groove in the dummy region is set for dividing the product region. A ceramic substrate shallower than the groove is disclosed.

  In Patent Document 3, a dummy region in which vertical and horizontal dividing grooves formed in the product region are provided outside the product region, and the end of the dividing groove in the dummy region is the outermost part of the ceramic substrate. A ceramic substrate that does not reach the side is disclosed.

  In Patent Document 4, a dummy region set in a ceramic substrate is composed of a first dummy region on the product region side and a second dummy region outside the first dummy region, and the surface of the first dummy region Is formed with vertical and horizontal dividing grooves, and vertical and / or horizontal cuts reaching the outer side of the surface of the second dummy region on the boundary extending between the first dummy region and the second dummy region. A technique for preventing the occurrence of cracks in the dividing grooves by forming the grooves is disclosed.

  In Patent Document 5, as a guide for positioning a press cutting cutting blade, solder bumps are formed at a plurality of locations along both sides of the line so as to sandwich the line to be cut of the printed circuit board at a predetermined interval. There is disclosed a technique that works as a guide for positioning a cutting blade.

  In Patent Document 6, a first resin diamond blade is used to form a cutting groove by performing first dicing on a silicon wafer, and then a second resin diamond blade having a width wider than this is used, along the cutting groove. A method of polishing the end face of the optical waveguide by subjecting the silicon wafer to second dicing is disclosed.

  However, Patent Documents 1 to 4 do not disclose means for preventing chipping from occurring at the edge during or after the division operation in application to a ceramic substrate made of LTCC. The same applies to Patent Documents 5 and 6.

Further, in any conventional technique, in particular, in a ceramic substrate made of LTCC, cracks and cracks sometimes run in unexpected directions at the intersections between the horizontal dividing grooves and the vertical dividing grooves.
Japanese Patent Laid-Open No. 11-17289 Japanese Patent Laid-Open No. 10-264130 Japanese Patent Laid-Open No. 9-11221 JP 2002-292619 A JP-A-8-162733 JP 2003-172839 A

  An object of the present invention is to provide a ceramic substrate capable of preventing occurrence of chipping at an edge and a method for manufacturing the same.

  Another object of the present invention is to provide a ceramic substrate that can be reliably divided along the grooves even at the intersections of the dividing grooves, and a method for manufacturing the same.

In order to solve the above-described problems, the present invention discloses a ceramic substrate and a manufacturing method thereof.
(1) Ceramic substrate The ceramic substrate according to the present invention has dividing grooves intersecting each other on at least one surface. Each of the dividing grooves includes a first groove portion and a second groove portion. The first groove portion is a narrow groove located at the back. The second groove portion includes a portion whose tip is continuous with the first groove portion and the groove width gradually expands toward the one surface.

  As described above, since the ceramic substrate according to the present invention has the dividing grooves intersecting each other on at least one surface, the ceramic substrate can be divided vertically and horizontally along the dividing grooves. In a ceramic substrate having an element formation region in a region surrounded by the dividing grooves, and the element formation region includes a large number of aligned elements, each element is individually separated by a dividing operation. Can be taken out as a single product.

  Each of the dividing grooves includes a second groove portion, and the second groove portion includes a portion where the groove width gradually expands toward one surface. Because of the presence of the second groove portion, the opening end appearing on one surface of the base is positioned inside the side end surface generated by the first groove portion, so that the chipping is performed on the opening end appearing on one surface of the base after division. Can be prevented from occurring.

  Moreover, each of the dividing grooves includes a first groove portion, and the first groove portion is a narrow-width groove located at the back. Accordingly, in the dividing operation, the first groove portion plays a leading role, and the dividing force when dividing the ceramic substrate is concentrated on the first groove portion. Can be divided accurately. If there is no first groove portion, it is necessary to divide at the bottom of the wide second groove portion, causing a problem that the dividing force is dispersed and a crack runs in an unexpected direction.

  The ceramic substrate according to the present invention typically includes a number of aligned elements, and the dividing groove is provided between the elements. In such a ceramic substrate, along with the downsizing and high functionality of electronic components, chip elements after division have been increasingly miniaturized and multi-layered, and accordingly, chipping or the like tends to occur at the edges, resulting in product yield. Has a problem that it will drop significantly. According to the ceramic substrate according to the present invention, such a problem can be reliably avoided.

The present invention is particularly effective when applied to a ceramic substrate made of an LTCC material. This is because the ceramic substrate made of LTCC material is susceptible to the above-mentioned chipping problem due to the brittleness caused by the material properties, and according to the present invention, such a problem can be avoided.
The second groove portion typically includes a V-shaped portion. The entire second groove portion may be V-shaped or partially V-shaped.

(2) Manufacturing Method of Ceramic Substrate In manufacturing the above-described ceramic substrate, first, a knife-shaped blade is pressed against at least one surface of the unfired ceramic substrate, and the first dividing groove extending in the first direction X is formed. Forming and then pressing a knife-like blade against at least one surface of the unfired ceramic substrate to extend in a second direction Y intersecting the first direction X, and the first dividing groove Forming a second dividing groove that intersects with the first dividing groove and then pressing a knife-like blade against the first dividing groove.

  As another method, the step of forming the first dividing groove and the step of forming the second dividing groove may be reversed in time. That is, the second groove portion is formed on the unfired ceramic substrate, then the first groove is formed, and then fired.

  Whichever of the above two methods is applied, the ceramic substrate according to the present invention can be produced efficiently and reliably.

  Specifically, the first groove portion can be formed by pressing into a non-fired ceramic substrate using a knife-like blade, and the second groove portion can be formed by grinding using a dicer. it can. The rotary blade of this dicer has a V-shaped outer peripheral grinding blade portion, and the shape of the rotary blade of this dicer becomes the shape of the second dividing groove.

  As described above, according to the present invention, it is possible to provide a ceramic substrate capable of preventing the occurrence of chipping at the edge during or after the division operation and a method for manufacturing the same.

  Other features of the present invention and the operational effects thereof will be described in more detail by embodiments with reference to the accompanying drawings.

(1) Ceramic Substrate FIG. 1 is a plan view showing an example of a ceramic substrate according to the present invention, and FIG. 2 is a front sectional view of the ceramic substrate shown in FIG. The substrate 1, which is the main part of the ceramic substrate, can be composed of various ceramic materials, for example, dielectric ceramic materials, magnetic ceramics, etc., as well as glass ceramic materials in which ceramic powder and glass powder are mixed. . The ceramic substrate used in the present invention is preferably an LTCC material. This is because the present invention is premised on dividing after firing. Since LTCC materials are already known, they can be selected and used. As an example, a combination of (Sr, Al, Si, B) -based glass 50 wt% and alumina 50 wt% can be mentioned. The ceramic substrate may be either a single layer type or a multilayer type.

  The element formation region 2 set on one surface of the substrate 1 includes a large number of aligned elements 21, and each of the elements 21 includes a conductor pattern. The illustrated element formation region 2 is a rectangular region, but is not necessarily limited to such a shape.

  On at least one surface side of the substrate 1, dividing grooves 31 and 41 that are orthogonal to each other are formed between the elements 21 in the element forming region 2. The illustrated embodiment shows an example in which the dividing grooves 32 and 42 are provided on the other surface side at positions facing the dividing grooves 31 and 41.

  In FIG. 1 and FIG. 2, only one element formation region 2 is shown, but a large number of element formation regions 2 may be arranged horizontally and vertically on a single substrate 1. In such a case, a similar dividing groove can be provided.

  3 is a partially enlarged plan view showing a part of the ceramic substrate shown in FIGS. 1 and 2 in an enlarged manner, FIG. 4 is a partially enlarged front view thereof, and FIG. 5 is a further enlarged view of FIG. . Referring to these drawings, each of the dividing grooves (31, 41) and (32, 42) includes a first groove portion 51 and a second groove portion 52.

  The first groove portion 51 is a narrow groove located in the back, and is formed by, for example, a knife-like blade. The depth H1 of the first groove 51 depends on the total thickness T1 of the base 1 and whether the dividing grooves (31, 41) and (32, 42) are provided on one side or both sides. Also changes. As an example, in the double-sided groove structure of the illustrated embodiment, when the thickness T1 (before firing) of the substrate 1 is around 1.2 mm, the depth H1 (before firing) of the first groove portion 51 is 0. It can be set in the range of 02 mm to 0.5 mm. Further, the groove width of the first groove portion 51 is about 0.1 mm to 0.7 mm.

  The second groove portion 52 includes a portion where the tip is continuous with the first groove portion 51 and the groove width W1 gradually expands toward one surface (surface). In the illustrated embodiment, the second groove portion 52 has inclined surfaces 53 and 54 that open on both sides at an opening angle θ1. Side walls 55 and 56 are connected to the inclined surfaces 53 and 54, respectively. The side wall surfaces 55 and 56 are substantially vertical in the drawing, but may be inclined surfaces. Therefore, the second groove portion 52 in the illustrated embodiment is partially V-shaped, but may be V-shaped throughout. The depth H2 (before firing) of the second groove portion 52 is 0.1 mm to 0.00 mm when the thickness T1 (before firing) of the substrate 1 is about 1.2 mm in the double-sided groove structure of the illustrated embodiment. It can be set in the range of 7 mm. Further, the groove width of the first groove portion 51 is about 0.01 mm to 0.1 mm.

  As described above, since the ceramic substrate according to the present invention has the dividing grooves (31, 41) and (32, 42) intersecting each other on at least one surface, the dividing grooves (31, 41) and (32, 42) can be divided vertically and horizontally. In the illustrated embodiment, the element forming region 2 has the dividing grooves (31, 41) and (32, 42) between each of the aligned many elements 21, so that each of the elements 21 is changed by the dividing operation. It can be taken out individually as a single item.

  Each of the dividing grooves (31, 41) and (32, 42) includes a second groove portion 52, and the second groove portion 52 includes a portion where the groove width W1 gradually expands toward one surface. It is out. Due to the presence of the second groove portion 52, the opening end E1 (see FIG. 5) appearing on one surface of the base body 1 is positioned inside the side end surface generated by the first groove portion 51. Chipping can be prevented from occurring at the opening end E1 appearing on one surface of the substrate 1.

  Moreover, each of the dividing grooves (31, 41) and (32, 42) includes a first groove portion 51, and the first groove portion 51 is a narrow-width groove located at the back. Therefore, in the dividing operation, the first groove portion 51 plays a leading role, and the dividing force when dividing the ceramic substrate is concentrated on the first groove portion 51. Therefore, the dividing groove (31, Even at the intersection of 41) and (32, 42), it can be reliably divided along the groove. As shown in FIG. 6, if there is no first groove portion, it is divided at the bottommost portion R1 of the wide second groove portion 52, so that the dividing force is dispersed without concentrating and expected. Problems such as cracks running in unexpected directions occur.

  The V-shaped portion preferably has an opening angle θ1 in the range of 20 degrees to 140 degrees. If the opening angle θ1 of the V-shaped part is less than 20 degrees, the substrate edge after the division is close to 90 degrees, so that chipping is likely to occur. If it exceeds 140 degrees, the area occupied by the substrate due to the dividing grooves (31, 41) and (32, 42) increases, and accordingly, the number of elements is reduced and the production efficiency is lowered.

The splitting quality of the ceramic substrate is determined by the ratio (T2 / T1) of the substrate thickness T1 (thickness before firing) and the thickness T2 (thickness before firing) of the portions without the dividing grooves (31, 41) and (32, 42). ). According to the experiment
1/3 ≦ T2 / T1 ≦ 9/10
It has been found that if the above condition is satisfied, it can be surely divided along the dividing grooves (31, 41) and (32, 42).

As an example, in the base 1 having a thickness T1 after firing of 1.261 mm before firing (1.019 mm after firing), the depth H2 (depth before firing) of the second groove portion 52 is set to 0.3 mm. In the ceramic substrate in which the depth H1 (depth before firing) of one groove portion 51 was 0.55 mm, it could be divided almost accurately along the dividing grooves. In this case, T2 / T1 is
T2 / T1 = 0.326
And satisfies the above conditional expression. As the ratio of (T2 / T1) approaches 1, the splitting property is improved, but on the other hand, the ceramic substrate may be broken even in scenes other than the splitting operation. In order to avoid such a situation, it is necessary to satisfy T2 / T1 ≦ 9/10.

  Next, it will be described in more detail with reference to the experimental data shown in Table 1. Table 1 shows the quality of division when a division groove is formed on a ceramic substrate having a thickness T1 = 1.261 mm before firing under the conditions shown in Table 1, and is divided after firing. An example of division failure is shown in FIG. 7, and an example of good division is shown in FIG.

  Referring to Table 1, for the thickness T1 = 1.261 mm before firing, Sample 1 in which the second groove portion 52 having a depth H2 = 0.3 mm was provided on the substrate surface, but the first groove portion 51 was not provided. Caused a division failure. The mode of division failure was as shown in FIG.

  In addition, the second groove portion 52 having a depth H2 = 0.3 mm was provided not only on the substrate surface but also on the back surface. However, even in the sample 2 in which the first groove portion 51 was not provided, division failure occurred. .

  In samples 1 and 2, the ratio (T2 / T1) between the substrate thickness T1 and the thickness T2 of the portion without the dividing groove is 0.762 and 0.524, respectively, and 1/3 ≦ T2 / T1 ≦ 9. Although / 10 is satisfied, since the first groove portion 51 is not provided, the result as described above is obtained.

  On the other hand, any of Samples 3 to 8 in which both the first groove portion 51 and the second groove portion 52 were provided on at least one of the front surface or the back surface of the substrate could be divided satisfactorily. . The mode of the good division was as shown in FIG. Samples 2 to 8 all satisfy the condition of 1/3 ≦ T2 / T1 ≦ 9/10.

  Therefore, in order to perform good division as shown in FIG. 8 after firing, providing the first groove portion 51 and the second groove portion 52 on at least one of the substrate front surface and the substrate back surface, Preferably, it is necessary to satisfy the condition of 1/3 ≦ T2 / T1 ≦ 9/10.

  Next, another embodiment of the ceramic substrate according to the present invention will be described with reference to FIGS. In these drawings, parts corresponding to those shown in FIGS. 1 to 6 are given the same reference numerals.

  First, in the embodiment of FIG. 9, the dividing grooves 31 and 41 on the one surface side of the base 1 include the first groove portion 51, but the dividing grooves 32 and 42 on the other surface side of the base 1. Does not include the first groove portion.

  Next, in the embodiment of FIG. 10, the dividing grooves 31 and 41 are provided only on one surface side of the base 1, and are not provided on the other surface side of the base 1.

  In the embodiment shown in FIG. 11, the second groove portion 52 is entirely constituted by a V-shaped groove.

  In the embodiment shown in FIG. 12, the dividing grooves 31 and 41 are provided only on one side of the base 1, and are not provided on the other side of the base 1.

  In the embodiment shown in FIG. 13, the dividing grooves (31, 41) and (32, 42) are deformed V-shaped grooves in which the second groove portion 52 has only one inclined surface 54. Yes.

  Even in the configuration shown in FIGS. 9 to 13, the above-described implementation can be performed by selecting the thickness of the substrate 1, the shape and depth of the dividing grooves (31, 41) and (32, 42), The same effect as the example can be obtained.

(2) Manufacturing method of ceramic substrate Next, the manufacturing method of the ceramic substrate mentioned above is demonstrated.

  First, as shown in FIGS. 14 and 15, the first groove portion 51 is formed on one surface of the unfired ceramic substrate 1 using, for example, a knife-like blade 7. The first groove portion 51 is formed so as to intersect vertically and horizontally (see FIGS. 1 and 2).

  Next, as shown in FIGS. 15 and 16, the second groove portion 51 is traced, that is, the second groove portion is overlapped with the first groove portion 51 as a reference. 52 is formed.

  The second groove portion 52 can be formed using the dicer 8 or the like. The dicer 8 is rotated around the central axis O1 as indicated by an arrow R1. The tip of the dicer 8 has a V shape having an opening angle θ2 corresponding to the opening angle of the second groove portion 52. The inclined surfaces 53 and 54 of the second groove portion 52 are formed by the both inclined surfaces 81 and 82 giving the opening angle θ2.

  Thereafter, firing is performed according to a normal process. And the ceramic substrate which concerns on this invention shown in FIGS. 1-13 is obtained by complete | finishing a baking process. Of course, the dicer 8 is prepared so as to fit the dividing groove of the ceramic substrate shown in FIGS.

  Unlike FIG. 14 to FIG. 16, a process of forming the second groove portion 52 in the unfired ceramic substrate 1 and then forming the first groove portion 51 may be employed.

  Although the contents of the present invention have been specifically described with reference to the preferred embodiments, various modifications can be made by those skilled in the art based on the basic technical idea and teachings of the present invention. It is self-explanatory.

It is a top view which shows an example of the ceramic substrate to which the manufacturing method concerning this invention is applied. It is front sectional drawing of the ceramic substrate shown in FIG. FIG. 3 is a partially enlarged plan view of the ceramic substrate shown in FIGS. 1 and 2. FIG. 3 is a partially enlarged front view of the ceramic substrate shown in FIGS. 1 and 2. FIG. 5 is an enlarged view of FIG. 4. It is a figure which shows the structure of the groove | channel for division | segmentation as a comparative example. It is a figure (photograph) which shows an example of a division defect. It is a figure (photograph) which shows a favorable example of a division | segmentation. It is a figure which shows the structure of the groove | channel for division | segmentation in another Example of the ceramic substrate which concerns on this invention. It is a figure which shows the structure of the groove | channel for division | segmentation in another Example of the ceramic substrate which concerns on this invention. It is a figure which shows the structure of the groove | channel for division | segmentation in another Example of the ceramic substrate which concerns on this invention. It is a figure which shows the structure of the groove | channel for division | segmentation in another Example of the ceramic substrate which concerns on this invention. It is a figure which shows the structure of the groove | channel for division | segmentation in another Example of the ceramic substrate which concerns on this invention. It is a figure which shows the manufacturing method of the ceramic substrate which concerns on this invention. It is a figure which shows the process after the process shown in FIG. FIG. 16 is a diagram showing a step after the step shown in FIG. 15.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base | substrate 2 Element formation area 31-34, 41-44 Dividing groove | channel 51 1st groove part 52 2nd groove part

Claims (9)

A ceramic substrate having dividing grooves intersecting each other on at least one surface,
Each of the dividing grooves includes a first groove portion and a second groove portion,
The first groove portion is a narrow groove located at the back,
The second groove portion is a ceramic substrate including a portion where a tip is connected to the first groove portion and a groove width gradually increases toward the one surface.   The ceramic substrate according to claim 1, wherein the ceramic substrate is made of a low-temperature co-fired ceramic material containing ceramics and glass.   3. The ceramic substrate according to claim 1, wherein the second groove portion includes a V-shaped portion.   4. The ceramic substrate according to claim 3, wherein the V-shaped portion has an opening angle in a range of 20 degrees to 140 degrees. The ceramic substrate according to any one of claims 1 to 4, wherein the substrate thickness is T1, and the thickness of the portion without the dividing groove is T2.
1/3 ≦ T2 / T1 ≦ 9/10
Meet ceramic substrate. A ceramic substrate according to any one of claims 1 to 5,
Contains a number of aligned elements,
The dividing groove is a ceramic substrate provided between the elements. A method for producing a ceramic substrate according to any one of claims 1 to 6,
Forming the first groove portion on the unfired ceramic substrate;
Next, the second groove portion is formed,
Then, the manufacturing method of the ceramic substrate including the process to bake. A method for producing a ceramic substrate according to any one of claims 1 to 6,
Forming the second groove portion on the unfired ceramic substrate;
Next, the first groove portion is formed,
Then, the manufacturing method of the ceramic substrate including the process to bake. A manufacturing method according to claim 7 or 8, wherein
The first groove portion is formed by pushing using a knife-like blade,
The manufacturing method of forming the second groove portion by grinding using a dicer.