JP2012199482A - Manufacturing method of ceramic multilayer substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ceramic multilayer substrate capable of improving a yield of a manufacturing step.SOLUTION: A manufacturing method of a ceramic multilayer substrate 1 having a ceramic substrate part 2 formed by burning a plurality of green sheets (a third green sheet 14, a first green sheet 15, a second green sheet 16, a fourth green sheet 17) and a chip-type electronic component 3 arranged inside the ceramic substrate part includes a lamination arrangement step of arranging the chip-type electronic component 3 on the first green sheet 15 and preparing a chip-type electronic component - green sheet laminate 12 in which the second green sheet 16 is arranged on the chip-type electronic component 3. A shrinkage factor when the first green sheet 15 is burnt differs from a shrinkage factor when the second green sheet 16 is burnt.

Description

  The present invention relates to a method for manufacturing a ceramic multilayer substrate.

Ceramic multilayer substrates are excellent in heat resistance and moisture resistance, and have good frequency characteristics in high frequency circuits. Therefore, they are used as substrates for electronic circuits using LEDs (Light Emitting Diodes) for liquid crystal backlights. It is used.
Currently, in order to further reduce the size of the LED for a liquid crystal backlight, it is required that a chip-type electronic component is built in the ceramic multilayer substrate (for example, a technique similar to this is disclosed in Patent Document 1 below). Are listed).

International Publication No. 2006/030562

  The problem with the conventional example is that in a ceramic multilayer substrate in which a plurality of ceramic green sheets are stacked and chip-type electronic components are further disposed between the green sheets, the stacked green sheets are fired. There was a gap near the chip-type electronic component electrode at both ends of the component. Due to the gap, for example, when a disturbance such as an impact is applied, the electrical connection between the built-in chip-type electronic component and the internal wiring portion of the ceramic multilayer substrate is disconnected, thereby producing the ceramic multilayer substrate. The process yield was reduced.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve this problem and improve the yield of a ceramic multilayer substrate manufacturing process.

  In order to achieve this object, the present invention provides a ceramic multilayer substrate having a ceramic substrate part formed by firing a plurality of green sheets, and a chip-type electronic component disposed inside the ceramic substrate part. In the manufacturing method, a chip-type electronic component-green sheet laminate is prepared in which the chip electronic component is disposed on a first green sheet and the second guileen sheet is further disposed on the chip electronic component. A method for producing a ceramic multilayer substrate, characterized in that the shrinkage rate during firing of the first green sheet is different from the shrinkage rate during firing of the second green sheet. did.

  This achieves the intended purpose.

As described above, the present invention relates to a method for producing a ceramic multilayer substrate having a ceramic substrate portion formed by firing a plurality of green sheets and a chip-type electronic component disposed inside the ceramic substrate portion. A stacking and arranging step of preparing a chip-type electronic component-green sheet laminate in which the chip electronic component is disposed on the first green sheet and the second guileen sheet is disposed on the chip electronic component; And having a different shrinkage ratio when firing the first green sheet and different shrinkage ratio when firing the second green sheet,
Thus, the yield of the manufacturing process of the ceramic multilayer substrate can be improved.

  That is, in the present invention, by changing the shrinkage rate during firing of the first green sheet disposed on the lower side of the chip electronic component and the second green sheet disposed on the upper side of the chip electronic component, Since the gap generated near the chip-type electronic component electrodes at both ends of the chip-type electronic component can be prevented, and the occurrence of poor electrical connection with the internal wiring portion of the ceramic substrate portion due to this gap can be prevented. As a result, the yield of the ceramic multilayer substrate manufacturing process can be improved.

Sectional drawing of the ceramic multilayer substrate in Embodiment 1 of this invention The figure which shows the process flow of the ceramic multilayer substrate in Embodiment 1 of this invention. FIG. 3A is a cross-sectional view of a green sheet according to Embodiment 1 of the present invention, FIG. 3A is a cross-sectional view of a third green sheet, FIG. 3B is a cross-sectional view of the first green sheet, and FIG. 3 (c) is a sectional view of the second green sheet, and FIG. 3 (d) is a sectional view of the fourth green sheet. Sectional drawing which shows the lamination | stacking procedure of the chip-type electronic component-green sheet laminated body in Embodiment 1 of this invention Sectional drawing of the chip-type electronic component-green sheet laminated body produced at the lamination | stacking arrangement | positioning process in Embodiment 1 of this invention Sectional drawing of the chip-type electronic component-green sheet laminated body produced at the baking process in Embodiment 1 of this invention Sectional view of chip-type electronic component-green sheet laminate formed in constraining layer removing step in Embodiment 1 of the present invention

In the following, embodiments of the ceramic substrate of the present invention will be described in detail with reference to the drawings.
(Embodiment 1)
First, the configuration of the ceramic multilayer substrate in Embodiment 1 of the present invention will be described.

FIG. 1 shows a cross-sectional view of the ceramic multilayer substrate in the first embodiment. As shown in FIG. 1, a ceramic multilayer substrate 1 includes a ceramic substrate portion 2 formed by firing a plurality of (specifically, four in the present embodiment, as will be described later) ceramic green sheets, and a ceramic. The chip-type electronic component 3 is disposed inside the substrate unit 2. Further, internal wiring portions 7 are connected to the chip-type electronic component electrodes 4 at both ends of the chip-type electronic component 3.
Further, a via 6 and an internal wiring portion 7 are formed around the chip-type electronic component 3 inside the ceramic substrate portion 2. Further, on the front and back surfaces of the ceramic substrate portion 2, an external electrode portion 9 for mounting a desired electronic component (for example, LED) on the ceramic multilayer substrate 1 and a desired external wiring portion 10 are provided.

  In the present embodiment, the ceramic substrate portion 2 will be described in detail again later. However, in any case, an alumina binder, a glass / ceramic solid component in which glass powder is blended at a certain ratio, and an organic binder containing an organic solvent. These are formed by laminating a plurality of (at least two or more) so-called green sheets of a sheet-like shape composed of a composition obtained by mixing and pressurizing, followed by firing at 900 [° C.]. In addition, in the ceramic substrate part 2 of this embodiment, what laminated | stacked and baked four green sheets was used.

Further, in this embodiment, the glass / ceramic solid component of the green sheet, the organic binder containing an organic solvent, and the mixing ratio are 4 sheets,
(1) The first green sheet 15 (green sheet disposed below the chip-type electronic component 3 when the ceramic multilayer substrate 1 is manufactured) is 85:15
(2) The second green sheet 16 (green sheet disposed on the upper side of the chip-type electronic component 3 when the ceramic multilayer substrate 1 is manufactured) is 89:11
(3) The third green sheet 14 (green sheet disposed below the first green sheet 15 when the ceramic multilayer substrate 1 is manufactured) is 89:11
(4) The fourth green sheet 17 (green sheet disposed on the upper side of the second green sheet 15 when the ceramic multilayer substrate 1 is manufactured) is 89:11
It was.

  Thus, by changing the mixing ratio of the glass / ceramic solid component of the green sheet and the organic binder containing the organic solvent, the shrinkage ratio at the time of firing of the green sheet can be changed.

  In particular, as described above, the first green sheet 15 (the green sheet disposed below the chip-type electronic component 3 when the ceramic multilayer substrate 1 is manufactured) is 85:15, and the second green sheet 16 (green sheet disposed on the upper side of the chip-type electronic component 3 when the ceramic multilayer substrate 1 is manufactured) is 89:11, so that the contraction rate of the first green sheet 15 is the second green It can be made smaller than the shrinkage rate of the sheet.

  In the present embodiment, the via 6 in the ceramic substrate portion 2 is formed with a hole in advance in the green sheet before firing by, for example, NC punch press (Numerical Control punch press), and then The hole is filled with a conductive paste, and is formed by firing at the same time when firing the ceramic sheet. In the present embodiment, a conductive paste containing silver (Ag) particles and a glass component was used.

  Further, in the present embodiment, the internal wiring portion 7 inside the ceramic substrate portion 2 is formed by printing in a desired pattern in advance using a screen printing method on the green sheet before firing. The ceramic sheet is formed by firing at the same time as firing. In the present embodiment, a conductive paste containing silver (Ag) particles and a glass component is used.

  In the present embodiment, the external electrodes 9 and the external wiring portions 10 on the front and back surfaces of the ceramic substrate portion 2 are formed by firing the above-described green sheet and then printing a conductor paste in a desired pattern using a screen printing method. Then, it forms by performing heat processing at the temperature lower than the temperature which bakes the above-mentioned ceramic sheet, and this conductor paste is fully baked. In the present embodiment, a conductor paste containing silver (Ag) particles and a glass component is used as in the via 6 and the internal wiring portion 7.

In the present embodiment, the chip-type electronic component 3 is a varistor that is often used in an electronic circuit that drives an LED for a liquid crystal backlight.
Then, the manufacturing method of the ceramic multilayer substrate 1 in Embodiment 1 of this invention is demonstrated below.

  FIG. 2 is a diagram showing a process flow of the ceramic multilayer substrate 1 of the present embodiment, which is roughly divided into a step 1: green sheet preparation step, a step 2: stacking and arranging step, a step 3: firing step, and a step. 4: Constraining layer removal process and Step 5: External electrode / electronic circuit pattern wiring part forming process, which consists of five steps.

[Step 1: Green sheet preparation process]
First, step 1 will be described with reference to FIG.

  FIG. 3 shows a cross-sectional view of the green sheet created in the green sheet preparation step according to Embodiment 1 of the present invention. FIG. 3 (a) is a cross-sectional view of the third green sheet, and FIG. 3 (b). Is a cross-sectional view of the first green sheet, FIG. 3C is a cross-sectional view of the second green sheet, and FIG. 4D is a cross-sectional view of the fourth green sheet.

In the present embodiment, as described above, mixing of a glass / ceramic solid component in which alumina powder is mixed at 55 [wt%] and glass powder at a ratio of 45 [wt%], and an organic binder containing an organic solvent is mixed. The ratios of the first green sheet 15, the second green sheet 16, the third green sheet 14, and the fourth green sheet 17,
(1) The first green sheet 15 (green sheet disposed below the chip-type electronic component 3 when the ceramic multilayer substrate 1 is manufactured) is 85:15
(2) The second green sheet 16 (green sheet disposed on the upper side of the chip-type electronic component 3 when the ceramic multilayer substrate 1 is manufactured) is 89:11
(3) The third green sheet 14 (green sheet disposed below the first green sheet 15 when the ceramic multilayer substrate 1 is manufactured) is 89:11
(4) The fourth green sheet 17 (green sheet disposed on the upper side of the second green sheet 15 when the ceramic multilayer substrate 1 is manufactured) is 89:11
As shown in FIGS. 3 (a) to 3 (d), the third green sheet 14 (FIG. 3 (a)), the first green sheet (the sheet-like shape) prepared as Green sheet 15 (FIG. 3B), second green sheet 16 (FIG. 3C), and fourth green sheet 17 (FIG. 3D).

  First, the third green sheet 14 shown in FIG. 3A will be described. A hole is formed in the third green sheet 14 by, for example, an NC punch press, and then the via 6 is formed by filling the hole with a conductive paste. Thus, the third green sheet 14 is completed.

  Next, the first green sheet 15 shown in FIG. 3B will be described. The first green sheet 15 first forms the via 6 as in the third green sheet 14. Next, a conductor paste is printed on the upper surface of the first green sheet 15 in a desired pattern using a clean printing method, and then the internal wiring portion 7 is formed. Thus, the first green sheet 15 is completed.

  Next, the second green sheet 16 shown in FIG. First, the second green sheet 16 forms the via 6 in the same manner as the third green sheet 14. Thus, the second green sheet 16 is completed.

  Next, the fourth green sheet 17 shown in FIG. First, the fourth green sheet 17 forms the via 6 in the same manner as the third green sheet 14. Thus, the fourth green sheet 17 is completed.

  The above is Step 1: Green sheet preparation process in this embodiment.

[Step 2: Lamination arrangement process]
Next, step 2 will be described with reference to FIGS.

  FIG. 4 is a cross-sectional view showing the stacking procedure of the chip-type electronic component-green sheet stack 12 in the first embodiment of the present invention. FIG. 5 shows a cross-sectional view of the chip-type electronic component-green sheet laminate 12 created in the lamination arrangement step in Embodiment 1 of the present invention.

  First, the constraining layer 13 shown in FIGS. 4 and 5 and later-described FIG. 6 will be described.

  Generally, a glass-ceramic composition in which alumina powder and glass powder are blended. When a high temperature is applied to a sheet-like green sheet, the alumina powder and the glass powder are baked, whereby the volume of the green sheet (planar) Direction and thickness direction).

  Also in the present embodiment, Step 3: the next step, which is the firing step, is a pressurizing step for pressurizing the chip-type electronic component-green sheet laminate 12. A constraining layer 13 made of ceramic of a component that is not fired at an applied temperature is arranged on the upper and lower surfaces so as to sandwich the green sheet 14, the first green sheet 15, the second green sheet 16, and the fourth green sheet 17. deep.

  As a result, the third green sheet 14, the first green sheet 15, the second green sheet 16, and the fourth green sheet 17 are arranged in the X direction and the Y direction (that is, the chip shown in FIG. 4). It does not shrink in the mold type electronic component-planar direction of the green sheet laminate 12 but shrinks only in the Z direction (that is, the thickness direction of the chip type electronic component-green sheet laminate 12). The constraining layer 13 is used so as not to shrink in the X and Y directions. In the present embodiment, a material obtained by molding alumina powder into a sheet shape is used as the constraining layer 13.

  Next, referring to FIG. 4, the third green sheet 14, the first green sheet 15, the second green sheet 16, the fourth green sheet 17, and the chip type electronic component 3 are laminated to form a chip type electronic component. -The method to prepare the green sheet laminated body 12 is demonstrated.

First, the third green sheet 14 is laminated on the constraining layer 13.
Next, the first green sheet 15 is placed on the third green sheet 14, and the vias 6 formed on the third green sheet 14 are aligned with the vias 6 formed on the first green sheet 15. As described above, the layers are stacked while being aligned.

  Next, chip-type electronic component electrodes at both ends of the chip-type electronic component 3 are disposed at desired locations on the first green sheet 15 (in this embodiment, between the internal wiring portions 7 as shown in FIG. 5). The chip-type electronic component 3 is stacked while performing alignment so that 4 comes.

  Next, the second green sheet 16 is laminated on the chip-type electronic component electrodes 4 at both ends of the chip-type electronic component 3 while performing alignment.

Next, a fourth green sheet 17 is formed on the second green sheet 16, and the via 6 formed on the second green sheet 16 and the via 6 formed on the fourth green sheet 17. Lamination is performed while aligning so that the positions match.
Finally, the constraining layer 13 is disposed on the green sheet 11C.

  In this way, a chip-type electronic component-green sheet laminate 12 as shown in FIG. 5 is prepared.

[Step 3: Firing step]
Next, the firing process in Step 3 will be described.

  In this step, after applying pressure from the upper and lower surfaces (constraint layer 13 side) of the chip-type electronic component-green sheet laminate 12 shown in FIG. 5, the third green sheet 14, the first green sheet 15, Heating is performed at a temperature at which the second green sheet 16 and the fourth green sheet 17 are fired.

  In this embodiment, the vertical pressure was 0.5 MPa, the applied heat temperature was 900 ° C., and the application time was 1 hour.

  After this firing step, as shown in FIG. 6, the chip-type electronic component-green sheet laminate 12 is contracted in the thickness direction.

[Step 4: constrained layer removal step]
Next, the constraining layer removing process in step 3 will be described.

  In this step, a mixture of 96 g of water and 4 g of alumina powder having an average particle size of 0.1 to 10 μm is sprayed from above the constraining layer 13 with compressed air having a pressure of 0.4 [MPa].

  By doing so, only the constraining layer 13 can be removed, as shown in FIG.

[Step 5: External Electrode / Electronic Circuit Pattern Wiring Forming Step]
Next, the external electrode / electronic circuit pattern wiring portion forming step of step 5 will be described.

  Desired external electrode portions 9 and external wiring portions 10 as shown in FIG. 1 are formed on the front and back surfaces (upper and lower surfaces) of the chip-type electronic component-green sheet laminate 12 fired in step 3.

  In the present embodiment, as described above, the conductor paste is printed and formed in a desired pattern using the screen printing method, and then the temperature is lower than the temperature applied in the firing step of Step 3 and the conductor is formed. It was formed by performing a heat treatment at a temperature at which the paste was sufficiently fired. In the present embodiment, a silver (Ag) paste having a firing temperature of 700 ° C. was used, and a heat treatment temperature for firing was 750 ° C.

  The chip-type electronic component-green sheet laminate 12 after this process becomes the ceramic multilayer substrate 1 of the present embodiment as shown in FIG.

As described above, the ceramic substrate of this embodiment can be manufactured by performing Step 1 to Step 5 shown in FIG.
As described above, in the present embodiment, a plurality of green sheets (the third green sheet 14, the first green sheet 15, the second green sheet 16, and the fourth green sheet 17) are formed by firing. In the method for manufacturing the ceramic multilayer substrate 1 having the ceramic substrate portion 2 and the chip-type electronic component 3 disposed inside the ceramic substrate portion 2, the chip electronic component 3 is disposed on the first green sheet 15. Furthermore, it has a lamination arrangement step of preparing a chip-type electronic component-green sheet laminate 12 in which the second guile sheet 16 is arranged on the chip electronic component 3, and firing the first green sheet 15. The ceramic multilayer substrate 1 is characterized in that the shrinkage rate of the second green sheet 16 and the shrinkage rate during firing of the second green sheet 16 are different. It can be improved yield process for manufacturing the multilayer substrate 1.

  That is, in the present embodiment, the shrinkage rate during firing of the first green sheet 15 disposed below the chip electronic component 3 and the second green sheet 16 disposed above the chip electronic component 3 is changed. As a result, the gap generated near the chip-type electronic component electrodes at both ends of the chip-type electronic component 3 is prevented, and the occurrence of poor electrical connection with the internal wiring portion 7 of the ceramic substrate 2 due to this gap is prevented. As a result, the yield of the manufacturing process of the ceramic multilayer substrate 1 can be improved.

  Since the ceramic multilayer substrate according to the present invention can improve the yield of the manufacturing process of the ceramic multilayer substrate, the substrate for LED for backlight for liquid crystal televisions and liquid crystal screens of mobile phones which have recently been popularized. It is greatly expected to be used as

DESCRIPTION OF SYMBOLS 1 Ceramic multilayer substrate 2 Ceramic substrate part 3 Chip-type electronic component 4 Chip-type electronic component electrode 6 Via 7 Internal wiring part 9 External electrode part 10 External wiring part 12 Chip-type electronic component-green sheet laminated body 13 Constrained layer 14 3rd Green sheet 15 First green sheet 16 Second green sheet 17 Fourth green sheet

Claims (3)

A ceramic substrate formed by firing a plurality of green sheets;
A chip-type electronic component disposed inside the ceramic substrate portion;
In a method for producing a ceramic multilayer substrate having
A stacking and arranging step of preparing a chip-type electronic component-green sheet laminate in which the chip electronic component is disposed on the first green sheet and the second guileen sheet is disposed on the chip electronic component; Have
The shrinkage ratio during firing of the first green sheet is different from the shrinkage ratio during firing of the second green sheet;
A method for producing a ceramic multilayer substrate. The shrinkage rate of the first green sheet is smaller than the shrinkage rate of the second green sheet;
The method for producing a ceramic multilayer substrate according to claim 1. The mixing ratio of the solid component and the organic binder in the first green sheet is 85:15,
And the mixing ratio of the solid component and the organic binder in the second green sheet is 89:11,
The method for producing a ceramic multilayer substrate according to claim 2.

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