A method for processing a carrier plate to improve warpage of a board

Abstract

The application discloses a kind of processing methods for improving plate warping of carrier plate, comprising the following steps: providing IC carrier plate substrate, substrate includes front line and back line, front line is high-density line, back line is large copper surface;Substrate is electroplated, substrate is clamped using electroplating clamping fixture, clamp jaw is arranged on clamp and clamps substrate, the angle of clamp jaw is adjusted, so that substrate is stretched in single direction;Front line and back line of substrate are electroplated using different jet speed and current density;High-speed jet and high current density are used for front line, low-speed jet and low current density are used for back line;After substrate is electroplated, tempering treatment is carried out;The warping amount of substrate after electroplating is measured, if the warping amount of substrate is less than 3mm, the compensation angle is calculated according to the warping angle formula of substrate, and the angle of clamp jaw of next electroplating is adjusted.The application can inhibit substrate warping, improve plating uniformity, reduce residual stress, and improve IC carrier plate reliability.

Description

Technical Field

[0001] This invention relates to the field of printed circuit board processing technology, and in particular to a carrier board processing method for improving board warping. Background Technology

[0002] The description in this section provides only background information related to the disclosure of this invention and does not constitute prior art.

[0003] With the development of high-performance computing and high-speed communication, IC substrates are gradually moving towards high-density interconnect (HDI) and advanced packaging (2.5D / 3D). However, substrates are prone to warping during electroplating and lamination processes due to differences in thermal expansion and residual stress, affecting chip bonding and assembly yield. Uneven plating thickness: differences in the front and back circuit structures lead to uneven current distribution. Decreased reliability: long-term stress concentration may cause interface peeling and cracking. Existing technologies mostly use single methods to improve these issues and cannot simultaneously solve both warping and uneven plating problems.

[0004] It should be noted that the above description of the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of the present invention and facilitating understanding by those skilled in the art. It should not be assumed that the above technical solutions are known to those skilled in the art simply because they have been described in the background section of this invention. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a substrate processing method that improves board warping, which can effectively suppress substrate warping, improve coating uniformity, reduce residual stress, and improve the reliability of IC substrates, in order to address the shortcomings of the prior art.

[0006] This application discloses a carrier plate processing method for improving board warping, including the following steps:

[0007] An IC substrate is provided, the substrate including front circuitry and back circuitry, the front circuitry being high-density circuitry and the back circuitry being a large copper surface;

[0008] The substrate is electroplated, and the substrate is clamped using an electroplating clamping fixture. The fixture is equipped with jaws for clamping the substrate. The angle of the jaws is adjusted so that the substrate is stretched in one direction.

[0009] Electroplating is performed on the front and back lines of the substrate using differentiated jetting speeds and current densities; wherein, high-speed jetting and high current density are used for the front lines, and low-speed jetting and low current density are used for the back lines.

[0010] After the substrate is electroplated, it is subjected to tempering treatment;

[0011] Measure the warpage of the substrate after electroplating. If the warpage is less than 3mm, calculate the compensation angle according to the substrate warpage angle formula and adjust the clamp angle for the next electroplating.

[0012] The formula for the substrate warp angle is: Warp angle = ( ).

[0013] Furthermore, in the above-mentioned method for processing carrier plates to improve board warping, the angle of the grippers is adjusted to 40°~60°.

[0014] Furthermore, in the above-mentioned method for processing the substrate to improve warping, the electroplating time for the substrate is 30 min to 120 min, pulse electroplating and DC electroplating are used, the temperature of the electroplating bath is 20℃ to 30℃, the concentration of copper sulfate in the electroplating bath is 140 g / L to 150 g / L, the concentration of sulfuric acid is 160 g / L to 180 g / L, and the concentration of chloride ions is 10 ppm to 30 ppm.

[0015] Furthermore, in the aforementioned method for processing a substrate to improve warping, the step "electroplating the front and back lines of the substrate using differentiated jetting speeds and current densities; wherein, high-speed jetting and high current density are used for the front lines, and low-speed jetting and low current density are used for the back lines" refers to a high-speed jetting speed of 1.5 m / s to 2.0 m / s and a high current density of 1.8 A / dm². 2 The velocity of the low-speed jet is 0.5 m / s to 1.0 m / s, and the current density is 1.0 A / dm³. 2 .

[0016] Furthermore, in the above-mentioned method for processing a substrate to improve warping, in the step of "tempering the substrate after electroplating", the heating rate of the tempering process is 1℃ / min ~ 3℃ / min, and the cooling rate of the tempering process is 1℃ / min ~ 3℃ / min.

[0017] In summary, the method used in the embodiments of the present invention has the following advantages:

[0018] The substrate processing method for improving board warping described in this invention effectively suppresses substrate warping by adjusting the clamps to introduce prestress during electroplating, improves coating uniformity by using differentiated jet speeds and current densities for front and back circuits, reduces residual stress and enhances structural stability through tempering, further improves warping accuracy through lattice differential alignment guidance, and utilizes mathematical models to assist in design, making warping control predictable and highly accurate.

[0019] To further understand the features and technical content of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are for reference and illustration only and are not intended to limit the present invention. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments or prior art of this specification, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the steps in the carrier plate processing method for improving board warping in an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of substrate warping in an embodiment of the present invention.

[0023] The reference numerals in the above figures are: 1, substrate; h, substrate bend height; w, substrate width. Detailed Implementation

[0024] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this specification, and not all embodiments. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this specification.

[0025] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can understand the advantages and effects of the present invention from the content disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of the present invention. Furthermore, the accompanying drawings of the present invention are for simple illustrative purposes only and are not depictions of actual dimensions; this is stated in advance. The following embodiments will further describe the relevant technical content of the present invention in detail, but the disclosed content is not intended to limit the scope of protection of the present invention.

[0026] It should be understood that while terms such as "first," "second," and "third" may be used in this document to describe various components or signals, these components or signals should not be limited by these terms. These terms are primarily used to distinguish one component from another, or one signal from another. Furthermore, the term "or" as used herein should, as appropriate, include any combination of one or more of the related listed items.

[0027] Reference Figures 1 to 2 As shown in the embodiment of this application, a carrier plate processing method for improving board warping is disclosed, including the following steps:

[0028] An IC carrier substrate 1 is provided, the substrate 1 includes front circuitry and back circuitry, the front circuitry is high-density circuitry, and the back circuitry is a large copper surface;

[0029] Electroplating is performed on the substrate 1. The substrate 1 is clamped using an electroplating clamping fixture. The fixture is provided with jaws for clamping the substrate 1. The angle of the jaws is adjusted so that the substrate 1 is stretched in one direction.

[0030] Electroplating is performed on the front and back lines of the substrate 1 using different jet speeds and current densities; wherein, high-speed jetting and high current density are used for the front lines, and low-speed jetting and low current density are used for the back lines.

[0031] After electroplating, the substrate 1 is subjected to tempering treatment to release internal residual stress.

[0032] Measure the warpage of the substrate after electroplating. If the warpage is less than 3mm, calculate the compensation angle according to the substrate warpage angle formula and adjust the clamp angle for the next electroplating.

[0033] The formula for the substrate warp angle is: Warp angle = ( ).

[0034] Specifically, in this embodiment, the angle of the gripper is adjusted to 40°~60°.

[0035] Specifically, in this embodiment, during the electroplating process of the substrate 1, the electroplating time is 30 min to 120 min, pulse electroplating and direct current electroplating are used, the temperature of the electroplating bath is 20℃ to 30℃, the concentration of copper sulfate in the electroplating bath is 140 g / L to 150 g / L, the concentration of sulfuric acid is 160 g / L to 180 g / L, and the concentration of chloride ions is 10 ppm to 30 ppm. This allows the copper lattice to grow in a limited manner on a specific crystal plane, generating directional differential arrangement. The differential arrangement guides the substrate 1 to release stress in a fixed direction, generating controllable micro-deformation, further improving the warpage control accuracy.

[0036] Specifically, in this embodiment, in the step "electroplating the front and back lines of the substrate 1 using differentiated jetting speeds and current densities; wherein, high-speed jetting and high current density are used for the front lines, and low-speed jetting and low current density are used for the back lines", the speed of the high-speed jetting is 1.5 m / s to 2.0 m / s, the high current density is 1.8 A / dm2, the speed of the low-speed jetting is 0.5 m / s to 1.0 m / s, and the low current density is 1.0 A / dm2.

[0037] Specifically, in this embodiment, in the step "tempering after electroplating the substrate", the heating rate of the tempering process is 1℃ / min ~ 3℃ / min, and the cooling rate of the tempering process is 1℃ / min ~ 3℃ / min.

[0038] By employing the method described above in this embodiment, the warpage of substrate 1 is effectively suppressed by adjusting the clamps to introduce prestress during the electroplating process. Different jet speeds and current densities for the front and back circuits are used to improve the uniformity of the plating layer. Tempering treatment reduces residual stress and enhances structural stability. Lattice differential alignment guidance further improves warpage accuracy. Mathematical model-assisted design makes warpage control predictable and highly accurate.

[0039] Example 1

[0040] Preparation of substrate 1: Select IC carrier substrate 1 with dimensions of 100mm*100mm*0.5mm.

[0041] Clamping before electroplating: Place the substrate 1 on the electroplating fixture and adjust the angle of the jaws (2) to 50° so that the substrate 1 is stretched in one direction.

[0042] Differentiated electroplating: Front-side circuitry: Electroplating solution is sprayed from the nozzle at a high-speed jet (1.8 m / s) with a current density of 2.2 A / dm². 2 Backside wiring: Electroplating solution is sprayed from nozzle (3) at a low speed (0.8 m / s) with a current density of 1.2 A / dm. 2 .

[0043] Tempering treatment: The electroplated substrate 1 is tempered in a nitrogen atmosphere at 200℃ for 1 hour. The heating rate of the tempering treatment is 1℃ / min ~ 3℃ / min, and the cooling rate of the tempering treatment is 1℃ / min ~ 3℃ / min.

[0044] Warpage Measurement and Compensation: Measure the warpage of substrate 1 after electroplating. If the warpage is less than 3mm, calculate the compensation angle using arctan according to the warpage angle formula of substrate 1, and adjust the clamp angle for the next electroplating.

[0045] The content disclosed above is only a preferred and feasible embodiment of the present invention, and is not intended to limit the scope of the patent application of the present invention. Therefore, all equivalent technical changes made using the contents of the present invention specification and drawings are included in the scope of the patent application of the present invention.

[0046] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0047] Although this application has been described by way of examples, those skilled in the art will know that this application has many modifications and variations without departing from the spirit of this application, and it is intended that the appended embodiments include these modifications and variations without departing from this application.

Claims

1. A method for processing a carrier plate to improve board warping, characterized in that, Includes the following steps: An IC substrate is provided, the substrate including front circuitry and back circuitry, the front circuitry being high-density circuitry and the back circuitry being a large copper surface; The substrate is electroplated, and the substrate is clamped using an electroplating clamping fixture. The fixture is equipped with jaws for clamping the substrate. The angle of the jaws is adjusted so that the substrate is stretched in one direction. Electroplating is performed on the front and back lines of the substrate using differentiated jetting speeds and current densities; wherein, high-speed jetting and high current density are used for the front lines, and low-speed jetting and low current density are used for the back lines. After the substrate is electroplated, it is subjected to tempering treatment; Measure the warpage of the substrate after electroplating. If the warpage is less than 3mm, calculate the compensation angle according to the substrate warpage angle formula and adjust the clamp angle for the next electroplating. The formula for the substrate warp angle is: Warp angle = ( ).

2. The carrier plate processing method for improving board warping according to claim 1, characterized in that, Adjust the angle of the gripper to 40°~60°.

3. The method for processing a carrier plate to improve board warping according to claim 1, characterized in that, During the electroplating process on the substrate, the electroplating time is 30 min to 120 min, pulse electroplating and DC electroplating are used, the temperature of the electroplating bath is 20℃ to 30℃, the concentration of copper sulfate in the electroplating bath is 140 g / L to 150 g / L, the concentration of sulfuric acid is 160 g / L to 180 g / L, and the concentration of chloride ions is 10 ppm to 30 ppm.

4. The method for processing a carrier plate to improve board warping according to claim 1, characterized in that, In the step "electroplating the front and back lines of the substrate using differentiated jetting velocities and current densities; wherein high-speed jetting and high current density are used for the front lines, and low-speed jetting and low current density are used for the back lines", the high-speed jetting velocity is 1.5 m / s to 2.0 m / s, and the high current density is 1.8 A / dm³. 2 The velocity of the low-speed jet is 0.5 m / s to 1.0 m / s, and the current density is 1.0 A / dm³. 2 .

5. The method for processing a carrier plate to improve board warping according to claim 1, characterized in that, In the step "tempering after electroplating the substrate", the heating rate of the tempering process is 1℃ / min ~ 3℃ / min, and the cooling rate of the tempering process is 1℃ / min ~ 3℃ / min.

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