Manufacturing method for ceramic circuit boards
The method addresses dust and burr issues in ceramic circuit board manufacturing by using controlled laser processing to form grooves, ensuring precise fracture and reduced burr formation, thereby enhancing the manufacturing process and product quality.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- PROTERIAL LTD
- Filing Date
- 2022-03-25
- Publication Date
- 2026-05-26
AI Technical Summary
Dust generation during laser processing of ceramic circuit boards leads to appearance deterioration, reduced laser transmittance, and inaccurate fracture positions with potential burr formation.
A method involving laser irradiation with specific energy density and frequency to form grooves on the ceramic substrate, followed by precise fracture along these grooves, minimizing dust and burr formation.
Suppresses dust generation, enhances fracture precision, and reduces burr occurrence, improving the manufacturing process and product quality of ceramic circuit boards.
Smart Images
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Abstract
Description
[Technical Field]
[0001] This disclosure relates to a method for manufacturing a ceramic circuit board, a ceramic aggregate substrate, and a ceramic circuit board. [Background technology]
[0002] Ceramic circuit boards are used, for example, in power conversion devices for power electronics, for insulation and heat dissipation. A ceramic circuit board has a structure in which a ceramic plate is sandwiched between multiple metal plates.
[0003] Ceramic circuit boards can be manufactured by the following method. First, a ceramic aggregate substrate is formed. Next, scribe lines are formed on the ceramic aggregate substrate by laser processing. The scribe lines consist of, for example, multiple holes. Next, the ceramic aggregate substrate is fractured along the scribe lines using a jig. The portion of the ceramic aggregate substrate separated by the fracture becomes a ceramic circuit board. A method for manufacturing ceramic circuit boards is disclosed in Patent Document 1. [Prior art documents] [Patent Documents]
[0004] [Patent Document 1] WO2021 / 200867 A1 [Overview of the project] [Problems that the invention aims to solve]
[0005] During laser processing, dust is generated. This dust can cause various problems. For example, if dust adheres to the ceramic circuit board, its appearance will deteriorate. Also, if dust adheres to the protective glass of the laser head, the laser transmittance of the protective glass will decrease. Furthermore, depending on the shape of the scribe line, when the ceramic assembly substrate is fractured at the scribe line, the accuracy of the fracture position may decrease, or burrs may be generated.
[0006] In one aspect of this disclosure, it is preferable to provide a method for manufacturing a ceramic circuit board, a ceramic aggregate substrate, and a ceramic circuit board that can suppress the above-mentioned problems. [Means for solving the problem]
[0007] (1) One aspect of the present disclosure is a method for manufacturing a ceramic circuit board from a ceramic aggregate substrate. The method includes a groove forming step of forming grooves by irradiating the surface of the ceramic aggregate substrate with a laser. The energy density of the laser in the groove forming step is 7.0 × 10⁻⁶ -5 mJ / μm 2 The above is 1 x 10 -3 mJ / μm 2 The following applies:
[0008] According to the method for manufacturing ceramic circuit boards, which is one aspect of this disclosure, the generation of dust can be suppressed. Furthermore, according to the method for manufacturing ceramic circuit boards, which is one aspect of this disclosure, when the ceramic aggregate substrate is fractured at the scribe line, the precision of the fracture position is high and burrs are less likely to occur.
[0009] (2) Another aspect of the present disclosure is a surface having a scribe line having the form of a groove, wherein the depth of the groove is 30 μm or more, and in a cross section perpendicular to the scribe line, the groove This is a ceramic aggregate substrate with a bottom width of 50 μm or less.
[0010] Another aspect of this disclosure, the ceramic aggregate substrate, exhibits high precision in the fracture location and is less prone to burr formation when fractured along the scribe line. (3) Another aspect of the present disclosure is a ceramic circuit board in which at least some of the end faces have a shape obtained by cutting a plate with grooves formed in it at the grooves, and the inclination angle of the portion of the end face corresponding to the side wall of the groove is 30 degrees or more.
[0011] Another aspect of the present disclosure is a ceramic circuit board with high-end face accuracy and low burr generation on the end face.
Brief Description of the Drawings
[0012] [Figure 1] It is an explanatory diagram showing an example of a method for manufacturing a ceramic circuit board. [Figure 2] It is a plan view showing a scribe line formed on the surface of a ceramic substrate. [Figure 3] It is a cross-sectional view showing the III-III cross-section in FIG. 2. [Figure 4] It is an explanatory diagram showing the mode of a pulsed laser. [Figure 5] It is a cross-sectional view showing a ceramic substrate in a cross-section perpendicular to the longitudinal direction of the scribe line and perpendicular to the main surface of the ceramic substrate. [Figure 6] It is a cross-sectional view showing a ceramic circuit board in a cross-section perpendicular to the end face and perpendicular to the main surface of the ceramic circuit board. [Figure 7] It is an optical microscope photograph showing the cross-sectional shape of a scribe line and its periphery in the cases of conditions N1, N4, and N6. [Figure 8] FIG. 8A is an electron microscope photograph and a three-dimensional image showing the shape of the end face in the case of condition N1. FIG. 8B is an electron microscope photograph and a three-dimensional image showing the shape of the end face in the case of condition N4. [Figure 9] It is an electron microscope photograph showing a scribe line and its periphery in the cases of conditions N1, N4, and N6. [Figure 10] It is an explanatory diagram showing the definition of the inclination angle J. [Figure 11] It is an explanatory diagram showing the definition of the inclination angle M.
Embodiments for Carrying Out the Invention
[0013] Exemplary embodiments of the present disclosure will be described with reference to the drawings. 1. Method for Manufacturing a Ceramic Circuit Board 13 An example of a manufacturing method for the ceramic circuit board 13 is shown in Figure 1. In step S1 of Figure 1, a copper plate 3 is joined to the surface of the silicon nitride substrate 1 using a brazing material. Next, a pattern is formed on the copper plate 3 by etching. If necessary, plating is performed on the surface of the copper plate 3. Through these steps, the ceramic assembly substrate 5 is completed. S1 corresponds to the joining process. The copper plate 3 corresponds to a metal plate. Alternatively, plating may be omitted in step S1, and then the ceramic assembly substrate 5 may be divided in step S4, which will be described later, and then each ceramic circuit board 13 may be plated.
[0014] Next, in S2 of Figure 1, a scribe line 9 is formed on the surface of the ceramic aggregate substrate 5. As shown in Figures 2 and 3, the scribe line 9 has the form of a groove. The groove extends continuously, for example, along the longitudinal direction of the scribe line 9. The scribe line 9 may also consist of multiple holes arranged in a row. Adjacent holes may be connected or separated.
[0015] The scribe lines 9 are formed by irradiating the surface of the ceramic aggregate substrate 5 with a laser using a laser irradiation device 7. S2 corresponds to the groove formation process. The laser irradiated onto the surface of the ceramic aggregate substrate 5 is, for example, a pulsed laser. As shown in Figure 4, the pulsed laser repeatedly irradiates pulses 11 at a constant period A. The unit of period A is μsec. The duration of each pulse 11 is denoted as duration B. The unit of duration B is μsec.
[0016] Let frequency C be the frequency of pulse 11. The unit of frequency C is kHz. Frequency C is preferably 100 kHz or higher. When frequency C is 100 kHz or higher, the energy per pulse decreases as frequency C increases, which can suppress the generation of dust.
[0017] Let the condensing diameter of the laser be the condensing diameter D. The unit of the condensing diameter D is μm. The condensing diameter D is preferably 50 μm or less. When the condensing diameter D is 50 μm or less, the width of the scribe line 9 becomes smaller. When the width of the scribe line 9 is small, the creepage distance becomes larger and the dielectric breakdown voltage is improved. The creepage distance means the distance along the surface of the silicon nitride substrate 1 between the end of the silicon nitride substrate 1 and the end of the copper plate 3 in the ceramic circuit board 13. Also, when the width of the scribe line 9 is small, the number of ceramic circuit boards 13 that can be obtained from one ceramic assembly substrate 5 increases.
[0018] Let the energy density of the laser be E. The energy density E is expressed by the following formula (1). Formula (1) E = F / (C×π×(D / 2) 2 ) In formula (1), F is the laser output. The unit of F is mJ. The unit of E is mJ / μm 2 is.
[0019] The energy density E is 7.0×10 -5 mJ / μm 2 or more and 1×10 -3 mJ / μm 2 or less. When the energy density E is 7.0×10 -5 mJ / μm 2 or more, the groove of the scribe line 9 can be made deeper. When the energy density E is 1×10 -3 mJ / μm 2 or less, dust is less likely to occur when irradiating with the laser. The energy density E is more preferably 1.8×10 -4 mJ / μm 2 or more. When the energy density E is 1.8×10 -4 mJ / μm 2 or more, the groove of the scribe line 9 can be made even deeper.
[0020] Also, when the energy density E is 1×10 -3 mJ / μm 2In the following cases, the width H of the opening tends to be small, the depth I of the groove tends to be large, the inclination angle J of the groove's side wall tends to be large, and the width W of the bottom tends to be small. The definitions of the width H of the opening, the depth I of the groove, the inclination angle J of the groove's side wall, and the width W of the bottom will be described later.
[0021] The smaller the width H of the opening, the more accurate the fracture position becomes when the ceramic aggregate substrate 5 is fractured at the scribe line 9, and the less likely burrs are to form. The greater the groove depth I, the more accurate the fracture position becomes when the ceramic aggregate substrate 5 is fractured at the scribe line 9, and the less likely burrs are to form.
[0022] The larger the inclination angle J of the groove's side wall, the more accurate the fracture position becomes when the ceramic aggregate substrate 5 is fractured at the scribe line 9, and the less likely burrs are to form. The smaller the width W of the bottom, the more accurate the fracture position becomes when the ceramic aggregate substrate 5 is fractured at the scribe line 9, and the less likely burrs are to form.
[0023] When S2 is performed, the laser irradiation device 7 moves relative to the surface of the ceramic substrate 5. Let G be the relative speed of the laser irradiation device 7 relative to the surface of the ceramic substrate 5. In S2, the speed of movement G is, for example, constant. Preferably, the speed of movement G is 8 m / min or more and 3000 m / min or less. For example, the position of the laser irradiation device 7 can be fixed, and the ceramic substrate 5 can be moved. Alternatively, the position of the ceramic aggregate substrate 5 can be fixed, and the position of the laser irradiation device 7 can be moved.
[0024] When the moving speed G is 8 m / min or higher, the productivity of the ceramic aggregate substrate 5 and the ceramic circuit board 13 is improved. When the moving speed G is 3000 m / min or lower, the variation in groove depth I in the longitudinal direction of the scribe line 9 is reduced.
[0025] By using a pulsed laser and maintaining a constant movement speed G, the productivity of the ceramic circuit board 13 is improved. Next, in step S3 of Figure 1, the ceramic aggregate substrate 5 is cleaned. S3 is a cleaning step. Cleaning removes the dust generated in S2. Cleaning improves the appearance of the ceramic aggregate substrate 5. Cleaning also suppresses the inhibition of film formation by dust during processes such as plating and solder resist printing. However, if dust is not easily generated in S2, step S3 may be omitted.
[0026] Next, in step S4 of Figure 1, the ceramic aggregate substrate 5 is divided along the scribe line 9. Step S4 is the dividing step. The resulting fragments are the ceramic circuit board 13. Note that step S1 may be performed after step S4. 2. Configuration of the ceramic aggregate substrate 5 The ceramic aggregate substrate 5 can be manufactured, for example, by performing steps S1 and S2 in Figure 1. The ceramic aggregate substrate 5 has scribe lines 9 having the form of grooves on its surface, for example, as shown in Figures 2 and 3.
[0027] Figure 5 shows the ceramic aggregate substrate 5 in a cross-section perpendicular to the longitudinal direction of the scribe line 9 and perpendicular to the main surface of the ceramic aggregate substrate 5. In Figure 5, the straight line L1 is a straight line that extends from the portion 15 of the surface of the ceramic aggregate substrate 5 where there are no scribe lines 9, up to the scribe lines 9.
[0028] In Figure 5, points P1 and P2 are the points where the side wall 9A of the scribe line 9 coincides with the straight line L1. In Figure 5, point P3 is the deepest point of the scribe line 9. The distance between point P3 and the straight line L1 is defined as the groove depth I. The groove depth I is preferably 30 μm or more. When the groove depth I is 30 μm or more, the accuracy of the fracture position is improved and burrs are less likely to occur when the ceramic aggregate substrate 5 is fractured at the scribe line 9.
[0029] In Figure 5, line L2 is the line obtained by translating line L1 in the direction of point P3 by a length of 5% of the groove depth I. In Figure 5, line L3 is the line obtained by translating line L1 in the direction of point P3 by a length of 95% of the groove depth I.
[0030] In Figure 5, points P4 and P5 are the intersections of line L2 and side wall 9A. Also, points P6 and P7 are the intersections of line L3 and side wall 9A. In Figure 5, the distance between points P4 and P5 is defined as the width H of the opening. The opening width H is preferably 100 μm or less. When the opening width H is 100 μm or less, the accuracy of the fracture position is improved and burrs are less likely to occur when the ceramic aggregate substrate 5 is fractured at the scribe line 9.
[0031] The inclination angle J of the side wall of the groove is defined as follows: In the right triangle shown in Figure 10, sides 101 and 102 are the two sides that enclose the right angle. Side 103 is the hypotenuse. The length of side 101 is 95% of the groove depth I. The length of side 102 is half the width H of the opening. The angle formed by side 102 and side 103 is the inclination angle J of the side wall of the groove. In the right triangle shown in Figure 10, This is also shown in Figure 5. Points P3 and P5 are the endpoints of side 103. Side 102 is parallel to lines L1, L2, and L3.
[0032] The inclination angle J of the groove sidewall is preferably 30 degrees or more. When the inclination angle J of the groove sidewall is 30 degrees or more, the accuracy of the fracture position is improved and burrs are less likely to occur when the ceramic aggregate substrate 5 is fractured at the scribe line 9.
[0033] It is even more preferable that the inclination angle J of the groove sidewall is 45 degrees or more. When the inclination angle J of the groove sidewall is 45 degrees or more, the accuracy of the fracture position is further improved and burrs are less likely to occur when the ceramic aggregate substrate 5 is fractured at the scribe line 9.
[0034] It is particularly preferable that the inclination angle J of the groove sidewall is 67.5 degrees or greater. When the inclination angle J of the groove sidewall is 67.5 degrees or greater, the accuracy of the fracture position is particularly improved and burrs are particularly less likely to occur when the ceramic aggregate substrate 5 is fractured at the scribe line 9.
[0035] In Figure 5, the distance between points P6 and P7 is defined as the width W of the base. The width W of the base is preferably 50 μm or less. When the width W of the base is 50 μm or less, the accuracy of the fracture position is improved and burrs are less likely to occur when the ceramic aggregate substrate 5 is fractured at the scribe line 9.
[0036] 3. Configuration of the ceramic circuit board 13 The ceramic circuit board 13 can be manufactured, for example, by performing steps S1 to S4 in Figure 1. Step S3 may be omitted.
[0037] At least a portion of the end face 16 of the ceramic circuit board 13 has the shape shown in Figure 6. The end face 16 comprises a first part 17 and a second part 19. Figure 6 shows a cross-section perpendicular to the end face 16 and perpendicular to the main surface of the ceramic circuit board 13.
[0038] The end face 16 is, for example, an end face formed by dividing the ceramic aggregate substrate 5 at the scribe line 9. In this case, the first part 17 is the portion that was the side wall 9A of the scribe line 9. That is, the first part 17 is the portion corresponding to the side wall of the groove. The second part 19 is an end face formed by fracture in a portion deeper than the scribe line 9. The second part 19 has, for example, a flatter shape than the first part 17.
[0039] In Figure 6, the straight line L11 is a straight line extending in the direction of the end face 16 from a flat portion 21 of the surface of the ceramic circuit board 13 that is sufficiently far from the end face 16. In Figure 6, point P11 is a point at the boundary between the first part 17 and the second part 19.
[0040] In Figure 6, the distance between point P11 and line L11 is defined as the groove depth K. In Figure 6, line L12 is a line obtained by translating line L11 in the direction of point P11 by a length of 5% of the groove depth K.
[0041] In Figure 6, line L13 is a line obtained by translating line L11 in the direction of point P11 by a length of 95% of the groove depth K. In Figure 6, point P12 is the intersection of line L12 and part 17. Also, point P13 is the intersection of line L13 and part 17.
[0042] In Figure 6, line L15 is a line that passes through point P11 and is perpendicular to line L11. In Figure 6, the distance between point P12 and line L15 is denoted as width Q. The inclination angle M of the side wall of the groove is defined as follows: In the right triangle shown in Figure 11, sides 201 and 202 are the two sides that enclose the right angle. Side 203 is the hypotenuse. The length of side 201 The depth is 95% of the groove depth K. The length of side 202 is equal to the width Q. The angle between side 202 and side 203 is the inclination angle M of the groove's side wall. The right triangle shown in Figure 11 is also shown in Figure 6. Points P11 and P12 are the endpoints of side 203. Side 202 is parallel to lines L11, L12, and L13.
[0043] The inclination angle M of the groove side wall is preferably 30 degrees or more. When the inclination angle M of the groove side wall is 30 degrees or more, the accuracy of the end face 16 is improved and burrs are less likely to occur on the end face 16. It is even more preferable that the inclination angle M of the groove side wall is 45 degrees or more. When the inclination angle M of the groove side wall is 45 degrees or more, the accuracy of the end face 16 is further improved, and burrs are less likely to occur on the end face 16.
[0044] It is particularly preferable that the inclination angle M of the groove side wall is 67.5 degrees or greater. When the inclination angle M of the groove side wall is 67.5 degrees or greater, the accuracy of the end face 16 is particularly improved, and burrs are particularly unlikely to occur on the end face 16.
[0045] 4. Examples (4-1) Manufacturing of silicon nitride substrate 1 The silicon nitride substrate 1 was manufactured by performing the following steps S11 to S14.
[0046] (i) Slurry preparation process S11 A raw material powder was obtained by adding a sintering aid to silicon powder. The sintering aids were yttrium oxide (Y2O3), a rare earth element oxide, and magnesium silicon nitride (MgSiN2), a magnesium compound. A slurry was prepared using the raw material powder. Furthermore, as rare earth element oxides, ytterbium oxide (Yb2O3), gadolinium oxide (Gd2O3), erbium oxide (Er2O3), lutetium oxide (Lu2O3), etc. may be used. In addition, as magnesium compounds, magnesium oxide (MgO), magnesium silicide (Mg2Si), magnesium nitride (Mg3N2), etc. may be used.
[0047] Let M1 be the number of moles of rare earth element oxides converted to trivalent oxides (RE2O3: RE is a rare earth element). Let M2 be the number of moles of silicon converted to silicon nitride (Si3N4). M2 is the number of moles of silicon nitride obtained when all silicon is nitrided. Let M3 be the number of moles of magnesium compounds converted to MgO.
[0048] The molar ratio of M1 to the total number of moles of M1, M2, and M3 was 1.2 mol%. The molar ratio of M3 to the total number of moles of M1, M2, and M3 was 9.8 mol%. To prepare the slurry, first, rare earth element oxides and magnesium compounds were added to silicon powder in predetermined ratios. Next, an organic solvent was added as a dispersion medium. Finally, the mixture was ground in a ball mill to produce a slurry, which is a dispersion of the raw material powders.
[0049] (ii) Molded body manufacturing process S12 To the slurry obtained as described above, a dispersion medium, an organic binder, and a dispersant were added. Next, vacuum degassing was performed. Then, the viscosity of the slurry was adjusted to a predetermined range. As a result, a coating slurry was obtained.
[0050] Next, the obtained coating slurry was formed into a sheet using a sheet molding machine. Then, it was cut to a predetermined size and dried. As a result, a sheet-like molded body was obtained. (iii) Sintering process S13, Nitriding process S14 Sintering process S13 includes a degreasing process to remove organic binder contained in the molded body, a nitriding process S14 to react silicon and nitrogen contained in the molded body to form silicon nitride, and a nitriding process S This includes a densification and sintering process that follows step 14.
[0051] In the sintering process S13, multiple molded bodies were stacked on a setter. The setter was made of boron nitride. A separating material was placed between the molded bodies. Weights were placed on top of the multiple molded bodies.
[0052] In this state, multiple molded bodies were placed in an electric furnace. Next, a degreasing process was carried out. Then, a decarbonization treatment was performed in a nitriding apparatus at a temperature of 900°C to 1300°C. Next, the nitriding process S14 was carried out. In the nitriding process S14, the temperature was raised to 1400°C in a nitrogen atmosphere.
[0053] Next, a densification sintering process was carried out in a sintering apparatus. The densification sintering process was performed while applying a load to the molded body using weights. Through these processes, silicon nitride substrate 1 was completed. (4-2) Manufacturing of ceramic circuit board 13 Using the silicon nitride substrate 1 manufactured in (4-1) above, the ceramic aggregate substrate 5 and the ceramic circuit board 13 were manufactured using the method described in section "1. Method for manufacturing ceramic circuit board 13".
[0054] The laser irradiation conditions used to form the scribe line 9 were conditions N1 to N6, as shown in Table 1 below.
[0055] [Table 1]
[0056] In all conditions N1 to N6, the focal position was 139.8 nm. The processing pitch in Table 1 is the value obtained by multiplying the travel speed G by the period A and expressing it in units of μm. The energy per laser pulse was 1.6, 0.8, 0.4, 0.27, 0.2, and 0.16 mJ for conditions N1 to N6, respectively.
[0057] (4-2) Evaluation of ceramic aggregate substrate 5 and ceramic circuit board 13 The amount of dust generated by laser irradiation was evaluated for each of the conditions N1 to N6. The evaluation method and criteria were as follows.
[0058] After laser irradiation, 36 locations on the ceramic aggregate substrate 5 were visually inspected. The observed locations were close to the scribe line 9. Next, the degree of dust was evaluated at each of the 36 locations according to the following criteria.
[0059] ○: No stains. △: There is a very minor, barely noticeable stain. □: There is a slightly noticeable stain.
[0060] ×: There are noticeable stains. The evaluation results are shown in Table 2.
[0061] [Table 2]
[0062] In Table 2, "OK" means less dust compared to "NG". The energy density E is 7.0 × 10⁻⁶. -5 mJ / μm 2 The above is 1 x 10 -3 mJ / μm 2 Dust was suppressed in the following cases:
[0063] Furthermore, the shape of the scribe line 9 was evaluated for each of the conditions N1, N3, and N6. Specifically, the width H of the opening, the depth I of the groove, the inclination angle J of the groove's side wall, and the width W of the bottom of the groove constituting the scribe line 9 were measured. The evaluation results are shown in Table 3.
[0064] [Table 3]
[0065] The energy density E in laser processing is 7.0 × 10⁻⁶ -5 mJ / μm 2 The above is 1 x 10 -3 mJ / μm 2 The following conditions indicate that the groove depth I is large, the inclination angle J of the groove sidewall is large, and the width W of the groove bottom is small.
[0066] Figure 7 shows the cross-sectional shape of the scribe line 9 and its surroundings under conditions N1, N4, and N6. In conditions N4 and N6, the groove depth I was greater, the bottom width W was smaller, and the inclination angle J of the groove sidewalls was greater compared to condition N1.
[0067] Figure 8A shows the shape of the end face 16 under condition N1. Figure 8B shows the shape of the end face 16 under condition N4. Under condition N4, the shape of the end face 16 was smoother with fewer irregularities compared to condition N1. Under condition N4, the inclination angle M of the side wall of the groove was 30 degrees or more. Figure 9 shows electron microscope images of the scribe line 9 and its surroundings under conditions N1, N4, and N6. The electron microscope images shown in Figure 9 were taken from a direction perpendicular to the main surface of the ceramic aggregate substrate 5. Under conditions N4 and N6, the area over which dust was scattered was smaller compared to condition N1.
[0068] 5. Other Embodiments Although embodiments of this disclosure have been described above, this disclosure is not limited to the embodiments described above and can be implemented in various modified forms.
[0069] (5-1) The function of one component in each of the above embodiments may be divided among multiple components, or the function of multiple components may be performed by one component. Also, some of the configurations of each of the above embodiments may be omitted. Also, at least some of the configurations of each of the above embodiments may be added to, replaced with, etc., the configurations of other embodiments.
[0070] (5-2) In addition to the ceramic circuit board described above, this disclosure can also be realized in various forms, such as a system using the ceramic circuit board as a component, or a method for manufacturing a ceramic aggregate substrate. [Explanation of Symbols]
[0071] 1...Silicon nitride substrate, 3...Copper plate, 5...Ceramic aggregate substrate, 7...Laser irradiation device, 9...Scribing line, 9A...Side wall, 11...Pulse, 13...Ceramic circuit board, 16... End face, 17...Part 1, 19...Part 2
Claims
1. A method for manufacturing a ceramic circuit board from a ceramic aggregate substrate, The process includes a groove forming step in which grooves are formed by irradiating the surface of the ceramic aggregate substrate with a laser, The energy density per unit time in one pulse of the laser during the groove forming process is 1.8 × 10² mJ / s·μm ２ Above, 2.5×10 3mJ / s・μm ２ The following conditions apply, and the ceramic substrate is not cleaned. A method for manufacturing ceramic circuit boards.
2. A method for manufacturing a ceramic circuit board according to claim 1, The laser is a pulsed laser with a frequency of 100 kHz or higher. A method for manufacturing ceramic circuit boards.
3. A method for manufacturing a ceramic circuit board according to claim 1 or 2, The focusing diameter of the aforementioned laser is 50 μm or less. A method for manufacturing ceramic circuit boards.
4. A method for manufacturing a ceramic circuit board according to any one of claims 1 to 3, The relative movement speed of the laser with respect to the surface of the ceramic aggregate substrate is 8 m / min or more and 3000 m / min or less. A method for manufacturing ceramic circuit boards.
5. A method for manufacturing a ceramic circuit board according to any one of claims 1 to 4, The process further comprises a bonding step of bonding a metal plate to the surface of the ceramic aggregate substrate. A method for manufacturing ceramic circuit boards.