A ceramic electroplating process

Abstract

The application relates to the technical field of electroplating, in particular to a ceramic electroplating process, which comprises the following steps: a conductive slurry solidified at one end of a through hole of a ceramic substrate to be plated is corroded in a first step to form a primary electroplating surface; after the primary electroplating surface is electroplated, the end surface of the conductive slurry which is not electroplated is corroded in a second step to form a secondary electroplating surface; the secondary electroplating surface is electroplated again to complete the complete electroplating of the through hole of the ceramic substrate; during the corrosion process, the corrosion time is determined according to the average unit corrosion height; during the electroplating process, the electroplating time is determined according to the average actual corrosion height; the two ends of the conductive slurry in the through hole of the ceramic substrate to be plated are corroded first and then electroplated, the height of the through hole electroplated each time is reduced when the size ratio of the radius and the height of the through hole is small, and the electroplating efficiency of the plating layer in the deposition process from bottom to top in the through hole is ensured.

Description

Technical Field

[0001] This invention relates to the field of electroplating technology, and more particularly to a ceramic electroplating process. Background Technology

[0002] With the rapid development of products such as semiconductor power modules, high-power integrated circuits, and 5G equipment that operate at high current, high temperature, and high frequency, higher requirements are being placed on chip substrates. Ceramic materials have stable chemical properties, good electrical insulation, excellent high-frequency characteristics, high thermal conductivity, low dielectric constant, and a linear expansion coefficient very similar to that of electronic components, making them widely used in the field of electronic substrates. However, since ceramics are not conductive, the bonding strength between the metal circuit layer and the ceramic substrate, as well as electroplating for via filling, are key to the reliability of ceramic substrates and crucial technologies in their fabrication. Electroplating for via filling is a key process in ceramic substrate technology, and achieving void-free filling within through-holes is the core requirement for achieving this.

[0003] Chinese Patent Publication No. CN114921821A discloses an electroplating apparatus for filling through holes and a TGV / TCV hole metallization method. The invention achieves the deposition of a coating layer from bottom to top by attaching a conductive back plate to the back of the workpiece, with the bottom of the non-conductive through hole serving as the cathode, and uses mechanical stirring to perform hole-filling electroplating on the workpiece.

[0004] In this technical solution, the conductive backplate consists of a conductive layer and a release layer. The release layer ensures the separation of the conductive backplate from the plated part after the electroplating filling is completed. The stirring device forms a strong liquid exchange by rotating at a controllable speed in the middle of the electroplating tank, which accelerates the electroplating rate inside the hole and reduces the problem of hollow holes caused by untimely exchange of plating solution. However, when the ratio of the radius to the height of the through hole is small, the exchange efficiency of the plating solution through mechanical stirring is not high during the deposition of the plating layer from bottom to top inside the through hole, resulting in low electroplating efficiency. Summary of the Invention

[0005] Therefore, the present invention provides a ceramic electroplating process to overcome the problem of low electroplating efficiency in the process of depositing the coating from bottom to top inside the through hole when the ratio of the radius to the height of the through hole is small.

[0006] To achieve the above objectives, the present invention provides a ceramic electroplating process, comprising:

[0007] Step S1: Fill each through hole of the ceramic substrate to be plated with conductive paste and cure it. Determine the expected etching height of the conductive paste in the through hole according to the height of the through hole.

[0008] Step S2: Use an etchant to perform a first-step etching on the conductive paste that has been cured at one end of the through hole. The first-step etching time is determined based on the first-step average unit etching height of the through hole, and the first-step average actual etching height is determined based on the first-step actual etching height of each through hole.

[0009] Step S3: Clean the through hole after the first step of etching under the conditions of the first electroplating start, and record the conductive paste end face in the through hole after the first step of etching as the first electroplating surface.

[0010] Step S4: Perform a first electroplating on the first electroplating surface, and determine the electroplating time for the first electroplating surface based on the average actual corrosion height in the first step.

[0011] Step S5: After the ceramic substrate is cleaned, dried, and a seed layer is sputtered onto the first reference surface and electroplated on the first reference surface, an etchant is used to perform a second etching on the unplated end face of the conductive paste. The second expected etching height of the conductive material in the through hole is determined according to the first expected etching height. The actual etching rate of the first etching is determined according to the etching time after the first etching is adjusted. The etching time of the second etching is determined according to the second actual etching height of each through hole.

[0012] Step S6: Clean the through hole after the second step of etching under the conditions for the start of the second electroplating, and record the end face of the through hole after the second step of etching that is in contact with the etchant as the second electroplating surface;

[0013] Step S7: Perform a second electroplating on the secondary electroplating surface, and determine the electroplating time for the secondary electroplating surface based on the average actual corrosion height in the second step.

[0014] Step S8: Under the conditions of secondary electroplating completion, the ceramic substrate is sequentially cleaned, dried, and a seed layer is sputtered on the second reference surface and electroplated on the second reference surface to complete the electroplating filling of the through hole and the electroplating of the ceramic substrate.

[0015] The conditions for starting the first electroplating are: the average actual corrosion height of the first step is greater than or equal to the expected corrosion height of the first step; the conditions for completing the first electroplating are: the average height of the through hole from the first reference surface after the first electroplating is greater than or equal to 0; and the conditions for starting the second electroplating are: the average actual corrosion height of the second step is greater than or equal to the expected corrosion height of the second step; and the conditions for completing the second electroplating are: the average height of the through hole from the second reference surface after the second electroplating is greater than or equal to 0.

[0016] Wherein, the first reference surface is the surface of the ceramic substrate to be plated, which is connected to the end of the through hole in the first step of etching, and the second reference surface is the surface of the ceramic substrate to be plated, which is connected to the end of the through hole in the second step of etching.

[0017] Furthermore, before step S1, step S0 is included, in which the central control unit determines whether to use the ceramic electroplating process to electroplat the ceramic substrate based on the ratio ΔRH of the radius R and height H of the through hole in the ceramic substrate to be plated. The central control unit is set with a preset ratio ΔRH0, where ΔRH = R / H.

[0018] If ΔRH≤ΔRH0, the central control unit determines that the ceramic electroplating process should be used to electroplat the ceramic substrate to be plated.

[0019] If ΔRH>ΔRH0, the central control unit determines that the ceramic electroplating process should not be used to electroplat the ceramic substrate to be plated.

[0020] Further, in step S1, the central control unit determines the expected primary corrosion height HQ1 of the conductive slurry based on the height H of the through hole. The central control unit is configured with a first through hole height H1, a second through hole height H2, a first height coefficient h1, a second height coefficient h2, and a third height coefficient h3, wherein H1 < H2, 0 < h1 < h2 < h3 < 0.5.

[0021] When H≤H1, the central control unit uses the first height coefficient h1 to determine the expected corrosion height HQ1 and sets HQ1=H×h1;

[0022] When H1 < H ≤ H2, the central control unit uses the second height coefficient h2 to determine the expected corrosion height HQ1 and sets HQ1 = H × h2;

[0023] When H > H2, the central control unit uses the third height coefficient h3 to determine the expected corrosion height HQ1 and sets HQ1 = H × h3.

[0024] Furthermore, in step S2, the central control unit determines the average unit corrosion height based on the data from the first step. The ratio ΔB to the standard unit corrosion height G0 determines the adjustment method for the corrosion time of the first step of corrosion. The central control unit is set with a first preset ratio ΔB1, a second preset ratio ΔB2, a first corrosion time coefficient t1, and a second corrosion time coefficient t2, wherein 0.8 < ΔB1 < 1 < ΔB2 < 1.2, 0 < t2 < 1 < t1 < 1.5, and the settings are as follows: G i Let be the first unit corrosion height of the i-th through-hole within a unit time t, and n be the total number of through-holes, i = 1, 2, 3, ..., n.

[0025] When ΔB≤ΔB1, the central control unit determines to adjust the corrosion time of the first step corrosion using the first corrosion time coefficient t1. The central control unit records the adjusted corrosion time of the first step corrosion as Ta, and sets Ta=TO×t1, where T0 is the initial corrosion time of the first step corrosion.

[0026] When ΔB1<ΔB≤ΔB2, the central control unit determines that there is no need to adjust the corrosion time of the first step of corrosion, and the central control unit sets Ta=T0;

[0027] When ΔB>ΔB2, the central control unit determines to adjust the corrosion time of the first step corrosion using the second corrosion time coefficient t2, and sets Ta=T0×t2.

[0028] Furthermore, in step S2, the central control unit determines the average actual corrosion height based on the data from the first step. The comparison result with the expected corrosion height HQ1 is used to determine whether the through hole meets the conditions for starting a first electroplating.

[0029] like The central control unit determines that the through hole meets the conditions for starting a first electroplating and executes step S3;

[0030] like The central control unit determines that the through hole does not meet the conditions for starting a first electroplating, and continues to execute step S2;

[0031] The first step, the average actual corrosion height This represents the average actual corrosion height of the conductive slurry in each through-hole after the first step of corrosion.

[0032] Furthermore, in step S4, the central control unit determines the average actual corrosion height based on the data from the first step. The electroplating time Da for the first electroplating surface is determined. The central control unit is configured with a first corrosion height G1, a second corrosion height G2, a first electroplating time coefficient d1, a second electroplating time coefficient d2, and a third electroplating time coefficient d3, wherein G1 < G2, d1 < d2 < d3.

[0033] when When the central control unit determines that the electroplating time Da is calculated using the first electroplating time coefficient d1, Da is set to D0 × d1, where D0 is the initial electroplating time of the first electroplating surface;

[0034] when At that time, the central control unit determines that the electroplating time Da is calculated using the second electroplating time coefficient d2, and sets Da = D0 × d2.

[0035] when When the central control unit determines that the electroplating time Da is calculated using the third electroplating time coefficient d3, the central control unit sets Da = D0 × d3.

[0036] Furthermore, in step S4, the central control unit determines the average height of the through hole from the first reference surface after one electroplating operation. To determine whether a single electroplating operation is complete, the height of the through-hole below the first reference surface after a single electroplating operation is recorded as a negative value, and the height of the through-hole above the first reference surface after a single electroplating operation is recorded as a positive value. M; is the height of the i-th through hole from the first reference surface after one electroplating operation.

[0037] like If the central control unit determines that the electroplating process is incomplete, it will continue to execute step S4:

[0038] like The central control unit determines that one electroplating operation is complete and executes step S5.

[0039] Furthermore, in step S4, the central control unit determines the average height of the through hole from the first reference surface after one electroplating operation. The ratio ΔR to the standard distance height M0 determines the adjustment method of the electroplating time Da. The central control unit is equipped with a third preset ratio ΔR1, a fourth preset ratio ΔR2, a fourth electroplating time coefficient k1, a fifth electroplating time coefficient k2, and a sixth electroplating time coefficient k3, wherein ΔR1 < ΔR2, 1 < k1 < k2 < k3 < 1.5, and the settings are as follows. M0 > 0,

[0040] When ΔR≤ΔR1, the central control unit determines to adjust the electroplating time Da using the fourth electroplating time coefficient k1 and records the electroplating time of the first electroplating surface after adjustment as Dat, and sets Dat=Da×k1;

[0041] When ΔR1<ΔR≤ΔR2, the central control unit determines to use the fifth electroplating time coefficient k2 to adjust the electroplating time Da, and sets Dat=Da×k2;

[0042] When ΔR>ΔR2, the central control unit determines to adjust the electroplating time Da using the sixth electroplating time coefficient k3, and sets Dat=Da×k3.

[0043] Further, in step S5, the central control unit determines the corrosion time Tb for the second corrosion step based on the actual corrosion rate v of the first corrosion step, and sets Tb = μ × HQ² / v. Where HQ2 is the secondary desired corrosion height, μ is the second-step corrosion adjustment coefficient, HQ2≥H-HQ1, 1<μ<1.2.

[0044] Furthermore, in step S5, the central control unit determines the average actual corrosion height based on the data from the second step. The comparison result with the secondary expected corrosion height HQ2 is used to determine whether the through hole meets the conditions for starting secondary electroplating.

[0045] like The central control unit determines that the through hole meets the conditions for starting secondary electroplating and executes step S6;

[0046] like The central control unit determines that the through hole does not meet the conditions for starting secondary electroplating and continues to execute step S5;

[0047] Among them, the average actual corrosion height in the second step This represents the average value of the actual corrosion height of the conductive material in each through-hole after the second step of corrosion.

[0048] Compared with the prior art, the beneficial effects of the present invention are as follows: the ceramic electroplating process of the present invention first etches the conductive paste solidified at one end of the through hole of the ceramic substrate to be plated to form a primary electroplating surface. After the primary electroplating surface is completed, the unplated end of the conductive paste is etched in the second step to form a secondary electroplating surface. The secondary electroplating surface is then electroplated again to complete the complete electroplating of the through hole of the ceramic substrate. In addition, the etching time is determined according to the average unit etching height during the etching process, and the electroplating time is determined according to the average actual etching height during the electroplating process. By etching both ends of the conductive paste in the through hole of the ceramic substrate to be plated before electroplating, the size ratio of the through hole radius to height is reduced, and the height of the through hole for each electroplating is reduced, thus ensuring the electroplating efficiency of the coating deposition process from bottom to top inside the through hole.

[0049] Furthermore, before step S1, there is also step S0, in which the central control unit determines whether to use the ceramic electroplating process to electroplat the ceramic substrate to be plated based on the ratio ΔRH of the radius R and height H of the through hole of the ceramic substrate to be plated. This specifies the usage conditions of the present invention and ensures the high efficiency of the present invention in electroplating the through hole of the ceramic substrate under the specified usage conditions.

[0050] Furthermore, in step s1, the central control unit determines the expected primary corrosion height HQ1 of the conductive paste based on the height H of the through hole, ensuring that the height of the subsequent first-step corrosion is less than the height of the through hole, and providing a basis for subsequent judgment on whether the conditions for starting a primary electroplating are met.

[0051] Furthermore, in step S2, the central control unit calculates the average unit corrosion height from the first step. The ratio ΔB to the standard unit corrosion height G0 determines the method for adjusting the corrosion time of the first step of corrosion, effectively controlling the actual corrosion height of the first step of corrosion and avoiding excessive or insufficient corrosion of the conductive paste.

[0052] Furthermore, in step S2, the central control unit determines the average actual corrosion height based on the data from the first step. The comparison with the expected corrosion height HQ1 determines whether the through hole meets the conditions for starting a first electroplating, ensuring that the through hole has the basis for a first electroplating and ensuring the efficiency of subsequent electroplating.

[0053] Furthermore, in step S4, the central control unit determines the average actual corrosion height based on the data from the first step. By determining the electroplating time Da for the first electroplating, the actual plating height of the first electroplating is effectively controlled, so that the plating height of the first electroplating is matched with the actual corrosion height of the first step of corrosion.

[0054] Furthermore, in step S4, the central control unit determines the average height of the through hole from the first reference surface after one electroplating operation. To determine whether a single electroplating operation is complete, if an operation is incomplete, electroplating is continued on the through-holes, ensuring the effectiveness of the through-hole electroplating.

[0055] Furthermore, in step S4, the central control unit determines the average height of the through hole from the first reference surface after one electroplating operation. The ratio ΔR to the standard distance height M0 determines the adjustment method of the electroplating time Da, which effectively controls the actual coating height of one electroplating, so that the coating height of one electroplating is matched with the actual corrosion height of the first step of corrosion.

[0056] Furthermore, in step S5, the central control unit determines the corrosion time Tb of the second step corrosion based on the actual corrosion rate v of the first step corrosion. Determining the corrosion time of the second step corrosion based on the corrosion rate of the first step corrosion can reduce the time required to adjust the corrosion time of the second step corrosion based on the experience of the first step corrosion, thereby improving the corrosion efficiency of the second step corrosion.

[0057] Furthermore, in step S5, the central control unit calculates the average actual corrosion height based on the data from the second step. The comparison results with the secondary expected corrosion height HQ2 determine whether the through hole meets the conditions for starting secondary electroplating, ensuring that the through hole has the basis for secondary electroplating and ensuring the efficiency of subsequent electroplating. Attached Figure Description

[0058] Figure 1 This is a schematic diagram of the ceramic electroplating process of the present invention;

[0059] Figure 2This is a schematic diagram of a through hole that meets the conditions for starting a single electroplating step according to an embodiment of the present invention;

[0060] Figure 3 This is a schematic diagram of a through hole that meets the conditions for one-time electroplating completion in an embodiment of the present invention;

[0061] Figure 4 This is a schematic diagram of a through hole that meets the conditions for starting secondary electroplating in an embodiment of the present invention;

[0062] Figure 5 This is a schematic diagram of a through hole that meets the conditions for completion of secondary electroplating in an embodiment of the present invention. Detailed Implementation

[0063] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0064] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0065] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0066] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0067] Please see Figures 1-5 As shown, Figure 1 This is a schematic diagram of the ceramic electroplating process of the present invention. Figure 2 This is a schematic diagram of a through hole that meets the conditions for starting a single electroplating step according to an embodiment of the present invention. Figure 3 This is a schematic diagram of a through hole that meets the conditions for one-time electroplating completion according to an embodiment of the present invention. Figure 4 This is a schematic diagram of a through hole that meets the conditions for starting secondary electroplating according to an embodiment of the present invention. Figure 5This is a schematic diagram of a through-hole conforming to the conditions for secondary electroplating completion in an embodiment of the present invention. The present invention provides a ceramic electroplating process, including:

[0068] Step S1: Fill each through hole of the ceramic substrate to be plated with conductive paste 1 and cure it. Determine the expected etching height of the conductive paste 1 in the through hole according to the height of the through hole.

[0069] Step S2: Use an etchant to perform the first step etching on the conductive paste 1 that has been cured at one end of the through hole. The first step etching time is determined based on the average unit etching height of the first step of the through hole, and the average actual etching height of the first step is determined based on the actual etching height of the first step of each through hole.

[0070] Step S3: Clean the through hole after the first step of etching under the conditions of the first electroplating start, and record the end face of the conductive paste 1 in the through hole after the first step of etching as the first electroplating surface 2.

[0071] Step S4: Perform a first electroplating on the first electroplating surface 2, and determine the electroplating time for the first electroplating surface 2 based on the average actual corrosion height in the first step.

[0072] Step S5: After the ceramic substrate is cleaned, dried and a seed layer is sputtered on the first reference surface 3 and electroplated on the first reference surface, an etchant is used to perform a second etching on the unplated end face of the conductive paste 1. The second expected etching height of the conductive material in the through hole is determined according to the first expected etching height. The actual etching rate of the first etching is determined according to the etching time after the first etching is adjusted. The etching time of the second etching is determined according to the second actual etching height of each through hole. The average actual etching height of the second etching is determined according to the second actual etching height of each through hole.

[0073] Step S6: Clean the through hole after the second step of etching under the conditions of the second electroplating start, and record the end face of the through hole after the second step of etching that is in contact with the etchant as the second electroplating surface 4.

[0074] Step S7: Perform secondary electroplating on the secondary electroplating surface 4, and determine the electroplating time for the secondary electroplating surface 4 based on the average actual corrosion height in the second step.

[0075] Step S8: Under the conditions of secondary electroplating completion, the ceramic substrate is sequentially cleaned, dried, and a seed layer is sputtered on the second reference surface 5 and electroplated on the first reference surface to complete the electroplating filling of the through hole and the electroplating of the ceramic substrate.

[0076] The conditions for starting a first electroplating are: the average actual corrosion height of the first step is greater than or equal to the expected corrosion height of the first step; the conditions for completing a first electroplating are: the average height of the through hole from the first reference surface 3 after the first electroplating is greater than or equal to 0; the conditions for starting a second electroplating are: the average actual corrosion height of the second step is greater than or equal to the expected corrosion height of the second step; the conditions for completing a second electroplating are: the average height of the through hole from the second reference surface 5 after the second electroplating is greater than or equal to 0.

[0077] Wherein, the first reference surface 3 is the surface of the ceramic substrate to be plated, which is connected to the end of the through hole for the first step of etching, and the second reference surface 5 is the surface of the ceramic substrate to be plated, which is connected to the end of the through hole for the second step of etching.

[0078] It is understandable that for through holes, the smaller the radius and the deeper the depth, the greater the probability of pores appearing in the conductive paste after filling the through hole, resulting in poor conductivity stability. In this solution, electroplating is used to replace the conductive paste. Through electroplating deposition, a dense metal deposition layer is formed inside the through hole. In this invention, to make the electroplating process faster and more efficient, the electroplating solution can be mechanically stirred or subjected to strong pressure to ensure timely exchange of liquids within the through hole, ensuring the effectiveness of the electroplating solution and avoiding pores in the coating due to a reduction in the effective components of the electroplating solution. As a preferred implementation, an appropriate amount of leveling agent can be added to the electroplating solution to improve the pore-filling ability of the electroplating and increase the efficiency of the electroplating process.

[0079] The conductive paste, etching solution, and electroplating solution mentioned in this invention can be set according to the specific application scenario, as long as they conform to the process of this invention, and will not be elaborated here.

[0080] Specifically, before step S1, step S0 is also included, in which the central control unit determines whether to use ceramic electroplating process to electroplat the ceramic substrate to be plated based on the ratio ΔRH of the radius R and height H of the through hole of the ceramic substrate to be plated. The central control unit is set with a preset ratio ΔRH0, and ΔRH = R / H is set.

[0081] If ΔRH≤ΔRH0, the central control unit determines that the ceramic electroplating process should be used to electroplat the ceramic substrate to be plated.

[0082] If ΔRH>ΔRH0, the central control unit determines that the ceramic electroplating process should not be used to electroplat the ceramic substrate to be plated.

[0083] It is understandable that the difficulty of electroplating through holes increases as the radius of the through hole decreases and the depth increases. The electroplating process of the present invention sets the electroplating start position in the middle of the through hole and is used on a ceramic substrate with a small ratio of through hole radius to height. Compared with the electroplating process where the electroplating start position is located at one end of the through hole, it provides a more open flow path for the electroplating solution, enabling the present invention to achieve better electroplating results than other electroplating processes.

[0084] Specifically, in step S1, the central control unit determines the expected primary corrosion height HQ1 of the conductive paste 1 based on the height H of the through hole. The central control unit is configured with a first through hole height H1, a second through hole height H2, a first height coefficient h1, a second height coefficient h2, and a third height coefficient h3, wherein H1 < H2, 0 < h1 < h2 < h3 < 0.5.

[0085] When H≤H1, the central control unit uses the first height coefficient h1 to determine the expected corrosion height HQ1 and sets HQ1=H×h1;

[0086] When H1 < H ≤ H2, the central control unit uses the second height coefficient h2 to determine the expected corrosion height HQ1 and sets HQ1 = H × h2;

[0087] When H > H2, the central control unit uses the third height coefficient h3 to determine the expected corrosion height HQ1 and sets HQ1 = H × h3.

[0088] It is understandable that determining the desired corrosion height based on the height of the through hole can ensure that the conductive paste in the through hole is corroded in the first step according to a certain height ratio. As a preferred implementation method, the first height coefficient h1 can be set to 0.25, the second height coefficient h2 to 0.35, and the third height coefficient h3 to 0.45.

[0089] Specifically, in step S2, the central control unit calculates the average unit corrosion height from the first step. The ratio ΔB to the standard unit corrosion height G0 determines the adjustment method for the corrosion time of the first step of corrosion. The central control unit is set with a first preset ratio ΔB1, a second preset ratio ΔB2, a first corrosion time coefficient t1, and a second corrosion time coefficient t2, wherein 0.8 < ΔB1 < 1 < ΔB2 < 1.2, 0 < t2 < 1 < t1 < 1.5, and the settings are as follows: Gi represents the first-step corrosion height per unit time t for the i-th via, and n is the total number of vias, i = 1, 2, 3, ..., n.

[0090] When ΔB≤ΔB1, the central control unit determines to adjust the corrosion time of the first step corrosion using the first corrosion time coefficient t1. The central control unit records the adjusted corrosion time of the first step corrosion as Ta, and sets Ta=T0×t1, where T0 is the initial corrosion time of the first step corrosion.

[0091] When ΔB1<ΔB≤ΔB2, the central control unit determines that there is no need to adjust the corrosion time of the first step of corrosion, and the central control unit sets Ta=T0;

[0092] When ΔB>ΔB2, the central control unit determines to adjust the corrosion time of the first step of corrosion using the second corrosion time coefficient t2, and sets Ta=T0×t2.

[0093] It is understandable that adjusting the corrosion time of the first step corrosion based on the ratio of the average unit corrosion height of the first step to the standard unit corrosion height can take into account the corrosion rate of each through hole and ensure that the average actual corrosion height of the first step can reach the expected corrosion height after the corrosion time of the first step corrosion. As a preferred implementation method, the first corrosion time coefficient t1 can be set to 0.7 and the second corrosion time coefficient t2 can be set to 1.3.

[0094] Specifically, in step S2, the central control unit calculates the average actual corrosion height from the first step. The comparison result with the expected corrosion height HQ1 is used to determine whether the through hole meets the conditions for starting a first electroplating.

[0095] like The central control unit determines that the through hole meets the conditions for starting a first electroplating and executes step S3;

[0096] like The central control unit determines that the through hole does not meet the conditions for starting a first electroplating, and continues to execute step S2;

[0097] Among them, the average actual corrosion height in the first step This represents the average actual corrosion height of the conductive paste 1 in each through hole after the first corrosion step.

[0098] Specifically, in step S4, the central control unit calculates the average actual corrosion height from the first step. The electroplating time Da for the first electroplating surface 2 is determined. The central control unit is set with a first corrosion height G1, a second corrosion height G2, a first electroplating time coefficient d1, a second electroplating time coefficient d2, and a third electroplating time coefficient d3, wherein G1 < G2, d1 < d2 < d3.

[0099] when When the central control unit determines that the first electroplating time coefficient d1 is used to calculate the electroplating time Da, Da = D0 × d1 is set, where D0 is the initial electroplating time of the electroplating surface 2 in one operation;

[0100] when At that time, the central control unit determines that the second electroplating time coefficient d2 is used to calculate the electroplating time Da, and sets Da = DO × d2.

[0101] when At that time, the central control unit determines that the third electroplating time coefficient d3 is used to calculate the electroplating time Da, and the central control unit sets Da = D0 × d3.

[0102] Specifically, in step S4, the central control unit determines the average height of the through hole from the first reference surface 3 after one electroplating. To determine whether a single electroplating operation is complete, a negative value is recorded when the height of the through-hole below the first reference surface 3 after a single electroplating operation, and a positive value is recorded when the height of the through-hole above the first reference surface 3 after a single electroplating operation. M i The height of the i-th through hole from the first reference surface 3 after one electroplating operation.

[0103] like The central control unit determines that the electroplating process is incomplete and continues to execute step S4.

[0104] like The central control unit determines that one electroplating operation is complete and executes step S5.

[0105] Understandably, after one electroplating is completed, a seed layer needs to be sputtered onto the first reference surface and then electroplated on the first reference surface. The plating layer formed by the first electroplating in the through hole is connected to the plating layer on the first reference surface through the seed layer, which strengthens the bonding strength between the plating layer formed by the first electroplating in the through hole and the ceramic substrate.

[0106] Specifically, in step S4, the central control unit determines the average height of the through hole from the first reference surface 3 after one electroplating. The ratio ΔR to the standard distance height M0 determines the adjustment method of the electroplating time Da. The central control unit is set with a third preset ratio ΔR1, a fourth preset ratio ΔR2, a fourth electroplating time coefficient k1, a fifth electroplating time coefficient k2, and a sixth electroplating time coefficient k3, wherein ΔR1 < ΔR2, 1 < k1 < k2 < k3 < 1.5. M0 > 0,

[0107] When ΔR≤ΔR1, the central control unit determines to use the fourth electroplating time coefficient k1 to adjust the electroplating time Da and records the adjusted electroplating time of the first electroplating surface 2 as Dat, and sets Dat=Da×k1;

[0108] When ΔR1<ΔR≤ΔR2, the central control unit determines to use the fifth electroplating time coefficient k2 to adjust the electroplating time Da, and sets Dat=Da×k2;

[0109] When ΔR>ΔR2, the central control unit determines to use the sixth electroplating time coefficient k3 to adjust the electroplating time Da, and sets Dat=Da×k3.

[0110] Specifically, in step S5, the central control unit determines the corrosion time Tb for the second step of corrosion based on the actual corrosion rate v of the first step of corrosion, and sets Tb = μ × HQ² / v. Where HQ2 is the secondary desired corrosion height, μ is the second-step corrosion adjustment coefficient, HQ2≥H-HQ1, 1<μ<1.2;

[0111] It is understandable that the present invention sets HQ2≥H-HQ1 to ensure that the second step of corrosion can completely corrode the conductive paste, avoiding the situation where the through hole contains conductive paste in addition to the electroplated layer after electroplating, resulting in poor conductivity.

[0112] Specifically, in step S5, the central control unit calculates the average actual corrosion height based on the second step. The comparison results with the secondary expected corrosion height HQ2 are used to determine whether the through hole meets the conditions for starting secondary electroplating.

[0113] like The central control unit determines that the through hole meets the conditions for starting secondary electroplating and executes step S6;

[0114] like The central control unit determines that the through hole does not meet the conditions for starting secondary electroplating and continues to execute step S5;

[0115] Among them, the average actual corrosion height in the second step This represents the average value of the actual corrosion height of the conductive material in each through-hole after the second corrosion step.

[0116] It is understandable that after the second electroplating is completed, a seed layer needs to be sputtered on the second reference surface and then electroplated on the second reference surface. The plating layer formed by the second electroplating in the through hole is connected to the plating layer on the second reference surface through the seed layer to ensure the bonding strength between the plating layer formed by the second electroplating in the through hole and the ceramic substrate. This ensures that after the overall electroplating of the ceramic substrate is completed, the plating layer in the through hole is firmly bonded to the ceramic substrate.

[0117] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

[0118] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A ceramic electroplating process, characterized in that, include: Step S1: Fill each through hole of the ceramic substrate to be plated with conductive paste and cure it. Determine the expected etching height of the conductive paste in the through hole according to the height of the through hole. Step S2: Use an etchant to perform a first-step etching on the conductive paste that has been cured at one end of the through hole. The first-step etching time is determined based on the first-step average unit etching height of the through hole, and the first-step average actual etching height is determined based on the first-step actual etching height of each through hole. Step S3: Clean the through hole after the first step of etching under the conditions of the first electroplating start, and record the conductive paste end face of the through hole after the first step of etching as the first electroplating surface. Step S4: Perform a first electroplating on the first electroplating surface, and determine the electroplating time for the first electroplating surface based on the average actual corrosion height in the first step. Step S5: After the ceramic substrate is cleaned, dried, and a seed layer is sputtered onto the first reference surface and electroplated on the first reference surface, an etchant is used to perform a second etching on the unplated end face of the conductive paste. The second expected etching height of the conductive material in the through hole is determined according to the first expected etching height. The actual etching rate of the first etching is determined according to the etching time after the first etching is adjusted. The etching time of the second etching is determined according to the second actual etching height of each through hole. Step S6: Clean the through hole after the second step of etching under the conditions for the start of the second electroplating, and record the end face of the through hole after the second step of etching that is in contact with the etchant as the second electroplating surface; Step S7: Perform a second electroplating on the secondary electroplating surface, and determine the electroplating time for the secondary electroplating surface based on the average actual corrosion height in the second step. Step S8: Under the conditions of secondary electroplating completion, the ceramic substrate is sequentially cleaned, dried, and a seed layer is sputtered on the second reference surface and electroplated on the second reference surface to complete the electroplating filling of the through hole and the electroplating of the ceramic substrate. The conditions for starting the first electroplating are: the average actual corrosion height of the first step is greater than or equal to the expected corrosion height of the first step; the conditions for completing the first electroplating are: the average height of the through hole from the first reference surface after the first electroplating is greater than or equal to 0; and the conditions for starting the second electroplating are: the average actual corrosion height of the second step is greater than or equal to the expected corrosion height of the second step; and the conditions for completing the second electroplating are: the average height of the through hole from the second reference surface after the second electroplating is greater than or equal to 0. Wherein, the first reference surface is the surface of the ceramic substrate to be plated, which is connected to the end of the through hole in the first step of etching, and the second reference surface is the surface of the ceramic substrate to be plated, which is connected to the end of the through hole in the second step of etching.

2. The ceramic electroplating process according to claim 1, characterized in that, Before step S1, there is also step S0, where the central control unit determines whether to use the ceramic electroplating process to electroplat the ceramic substrate based on the ratio ΔRH of the radius R and height H of the through hole in the ceramic substrate to be plated. The central control unit is set with a preset ratio ΔRH0, where ΔRH = R / H. If ΔRH≤ΔRHO, the central control unit determines that the ceramic electroplating process should be used to electroplat the ceramic substrate to be plated. If ΔRH>ΔRHO, the central control unit determines that the ceramic electroplating process should not be used to electroplat the ceramic substrate to be plated.

3. The ceramic electroplating process according to claim 2, characterized in that, In step S1, the central control unit determines the expected primary corrosion height HQ1 of the conductive slurry based on the height H of the through hole. The central control unit is configured with a first through hole height H1, a second through hole height H2, a first height coefficient h1, a second height coefficient h2, and a third height coefficient h3, wherein H1 < H2, 0 < h1 < h2 < h3 < 0.

5. When H≤H1, the central control unit uses the first height coefficient h1 to determine the expected corrosion height HQ1 and sets HQ1=H×h1; When H1 < H ≤ H2, the central control unit uses the second height coefficient h2 to determine the expected corrosion height HQ1 and sets HQ1 = H × h2; When H > H2, the central control unit uses the third height coefficient h3 to determine the expected corrosion height HQ1 and sets HQ1 = H × h3.

4. The ceramic electroplating process according to claim 3, characterized in that, In step S2, the central control unit calculates the average unit corrosion height from the first step. The ratio ΔB to the standard unit corrosion height G0 determines the adjustment method for the corrosion time of the first step of corrosion. The central control unit is set with a first preset ratio ΔB1, a second preset ratio ΔB2, a first corrosion time coefficient t1, and a second corrosion time coefficient t2, wherein 0.8 < ΔB1 < 1 < ΔB2 < 1.2, 0 < t2 < 1 < t1 < 1.5, and the settings are as follows: G i Let be the first unit corrosion height of the i-th through-hole within a unit time t, and n be the total number of through-holes, i = 1, 2, 3, ..., n. When ΔB≤ΔB1, the central control unit determines to adjust the corrosion time of the first step corrosion using the first corrosion time coefficient t1. The central control unit records the adjusted corrosion time of the first step corrosion as Ta, and sets Ta=T0×t1, where T0 is the initial corrosion time of the first step corrosion. When ΔB1<ΔB≤ΔB2, the central control unit determines that there is no need to adjust the corrosion time of the first step of corrosion, and the central control unit sets Ta=T0; When ΔB>ΔB2, the central control unit determines to adjust the corrosion time of the first step corrosion using the second corrosion time coefficient t2, and sets Ta=T0×t2.

5. The ceramic electroplating process according to claim 4, characterized in that, In step S2, the central control unit calculates the average actual corrosion height from the first step. The comparison result with the expected corrosion height HQ1 is used to determine whether the through hole meets the conditions for starting a first electroplating. like The central control unit determines that the through hole meets the conditions for starting a first electroplating and executes step S3; like The central control unit determines that the through hole does not meet the conditions for starting a first electroplating, and continues to execute step S2; The first step, the average actual corrosion height This represents the average actual corrosion height of the conductive slurry in each through-hole after the first step of corrosion.

6. The ceramic electroplating process according to claim 5, characterized in that, In step S4, the central control unit calculates the average actual corrosion height from the first step. The electroplating time Da for the first electroplating surface is determined. The central control unit is configured with a first corrosion height G1, a second corrosion height G2, a first electroplating time coefficient d1, a second electroplating time coefficient d2, and a third electroplating time coefficient d3, wherein G1 < G2, d1 < d2 < d3. when When the central control unit determines that the electroplating time Da is calculated using the first electroplating time coefficient d1, Da is set to D0 × d1, where D0 is the initial electroplating time of the first electroplating surface; when At that time, the central control unit determines that the electroplating time Da is calculated using the second electroplating time coefficient d2, and sets Da = D0 × d2. when When the central control unit determines that the electroplating time Da is calculated using the third electroplating time coefficient d3, the central control unit sets Da = D0 × d3.

7. The ceramic electroplating process according to claim 6, characterized in that, In step S4, the central control unit determines the average height of the through hole from the first reference surface after one electroplating process. To determine whether a single electroplating operation is complete, the height of the through-hole below the first reference surface after a single electroplating operation is recorded as a negative value, and the height of the through-hole above the first reference surface after a single electroplating operation is recorded as a positive value. Mi is the height of the i-th through hole from the first reference surface after one electroplating. like The central control unit determines that the electroplating process is not completed and continues to execute step S4. like The central control unit determines that one electroplating operation is complete and executes step S5.

8. The ceramic electroplating process according to claim 7, characterized in that, In step S4, the central control unit determines the average height of the through hole from the first reference surface after one electroplating process. The ratio ΔR to the standard distance height M0 determines the adjustment method of the electroplating time Da. The central control unit is equipped with a third preset ratio ΔR1, a fourth preset ratio ΔR2, a fourth electroplating time coefficient k1, a fifth electroplating time coefficient k2, and a sixth electroplating time coefficient k3, wherein ΔR1 < ΔR2, 1 < k1 < k2 < k3 < 1.5, and the settings are as follows. M0 > 0, When ΔR≤ΔR1, the central control unit determines to adjust the electroplating time Da using the fourth electroplating time coefficient k1 and records the electroplating time of the first electroplating surface after adjustment as Dat, and sets Dat=Da×k1; When ΔR1<ΔR≤ΔR2, the central control unit determines to use the fifth electroplating time coefficient k2 to adjust the electroplating time Da, and sets Dat=Da×k2; When ΔR>ΔR2, the central control unit determines to adjust the electroplating time Da using the sixth electroplating time coefficient k3, and sets Dat=Da×k3.

9. The ceramic electroplating process according to claim 8, characterized in that, In step S5, the central control unit determines the corrosion time Tb for the second step of corrosion based on the actual corrosion rate v of the first step of corrosion, and sets Tb = μ × HQ² / v. Where HQ2 is the secondary desired corrosion height, μ is the second-step corrosion adjustment coefficient, HQ2≥H-HQ1, 1<μ<1.

2.

10. The ceramic electroplating process according to claim 9, characterized in that, In step S5, the central control unit calculates the average actual corrosion height based on the second step. The comparison result with the secondary expected corrosion height HQ2 is used to determine whether the through hole meets the conditions for starting secondary electroplating. like The central control unit determines that the through hole meets the conditions for starting secondary electroplating and executes step S6; like The central control unit determines that the through hole does not meet the conditions for starting secondary electroplating and continues to execute step S5; Among them, the average actual corrosion height in the second step This represents the average value of the actual corrosion height of the conductive material in each through-hole after the second step of corrosion.

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