Grooving method for DDR5 products

Abstract

The application discloses a slotting method for a DDR5 product and relates to the technical field of packaging substrates. The method comprises the following steps: obtaining a copper-clad substrate and drilling the copper-clad substrate; manufacturing lines and leads on the surface of the copper-clad substrate; setting a solder resist layer on the surface of the copper-clad substrate and performing windowing on the solder resist layer to expose the pads and the leads; attaching a photosensitive dry film to the surface of the solder resist layer and performing exposure and development on the photosensitive dry film to expose the pads and cover the leads; electroplating a soft gold layer on the pads; removing the photosensitive dry film and removing the leads through alkaline etching; performing layer-by-layer milling on the copper-clad substrate by using a left-handed double-blade knife to form slotting; milling the copper-clad substrate to form a shaped small plate; and cleaning, detecting and packaging the shaped small plate. According to the method, the slotting quality can be improved, and problems such as burrs or substrate cracking can be avoided.

Description

Technical Field

[0001] This invention relates to the field of packaging substrate technology, and in particular to a slotting method for DDR5 products. Background Technology

[0002] During the manufacturing process of DDR5 products, gold fingers need to be made so that the DDR5 products can make electrical connections with the motherboard. At the same time, a slot also needs to be made as the physical interface for the gold fingers. Currently, problems such as copper burrs or substrate cracking can occur during the slot manufacturing process. Summary of the Invention

[0003] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a slotting method for DDR5 products, which can improve the slotting quality and avoid problems such as burrs or substrate cracking.

[0004] On one hand, the grooving method for a DDR5 product according to an embodiment of the present invention includes the following steps:

[0005] Obtain a copper-clad substrate and drill holes in the copper-clad substrate;

[0006] Lines and leads are fabricated on the surface of the copper-clad substrate;

[0007] A solder resist layer is formed on the surface of the copper-clad substrate, and a window is made in the solder resist layer to expose the pads and the leads;

[0008] A photosensitive dry film is attached to the surface of the solder mask layer, and the photosensitive dry film is exposed and developed to expose the solder pads and cover the leads.

[0009] Electroplating a soft gold layer onto the pads;

[0010] Remove the photosensitive dry film and remove the leads by alkaline etching;

[0011] A left-handed double-edged milling cutter is used to mill grooves in layers on the copper-clad substrate to form grooves;

[0012] The copper-clad substrate is milled to form a molded small board;

[0013] The molded small plates are then cleaned, inspected, and packaged.

[0014] According to some embodiments of the present invention, obtaining the copper-clad substrate and drilling holes in the copper-clad substrate includes:

[0015] The copper-clad substrate is obtained by cutting, baking, and Panel2D processing of the original substrate;

[0016] The copper content of the copper-clad substrate is reduced.

[0017] Mechanical drilling is performed on the copper-clad substrate;

[0018] The Desmear process removes the adhesive residue generated after drilling.

[0019] According to some embodiments of the present invention, before electroplating the soft gold layer onto the pads, the process further includes:

[0020] The copper-clad substrate is subjected to a soft gold pretreatment.

[0021] The oxide layer on the surface of the pads is removed by micro-etching.

[0022] According to some embodiments of the present invention, the step of using a left-handed double-edged milling cutter to perform layered milling on the copper-clad substrate to form grooves includes:

[0023] Using the left-handed double-edged cutter, the copper-clad substrate is pre-milled clockwise with a first rotational speed and a first milling speed to create a layered pre-milling groove.

[0024] After completing the layered pre-milling groove, the wear of the left-handed double-edged cutter is detected, and the parameters of the left-handed double-edged cutter are compensated.

[0025] The copper-clad substrate is precision-milled counterclockwise using a compensated left-handed double-edged cutter at a second rotational speed and a second milling speed; the second rotational speed is less than the first rotational speed, and the second milling speed is greater than the first milling speed.

[0026] According to some embodiments of the present invention, when milling grooves, the feed rate of the left-handed double-edged cutter is less than the retraction rate.

[0027] On the other hand, the grooving method for a DDR5 product according to an embodiment of the present invention includes the following steps:

[0028] Obtain a copper-clad substrate and drill holes in the copper-clad substrate;

[0029] Lines and leads are fabricated on the surface of the copper-clad substrate;

[0030] A solder resist layer is formed on the surface of the copper-clad substrate, and a window is made in the solder resist layer to expose the pads and the leads;

[0031] A first photosensitive dry film is attached to the surface of the solder mask layer, and the first photosensitive dry film is exposed and developed to expose part of the solder pads and cover the remaining solder pads and leads;

[0032] The exposed portion of the solder pads is electroplated with a soft gold layer;

[0033] Remove the first photosensitive dry film and attach a second photosensitive dry film to the surface of the solder resist layer;

[0034] The second photosensitive dry film is exposed and developed to expose the leads;

[0035] The leads are removed by alkaline etching, and the second photosensitive dry film is also removed.

[0036] A third photosensitive dry film is attached to the surface of the solder resist layer, and the third photosensitive dry film is exposed and developed to reveal the milled groove position;

[0037] A left-handed double-edged milling cutter is used to mill a groove at the milling groove location to form a slot.

[0038] Remove the third photosensitive dry film, and mill the copper-clad substrate to form a molded small board;

[0039] An organic protective film is applied to the surface of the pads that are not plated with a soft gold layer;

[0040] The molded small plates are then cleaned, inspected, and packaged.

[0041] On the other hand, the grooving method for a DDR5 product according to an embodiment of the present invention includes the following steps:

[0042] Obtain a copper-clad substrate and drill holes in the copper-clad substrate;

[0043] A circuit is fabricated on the surface of the copper-clad substrate;

[0044] A solder resist layer is formed on the surface of the copper-clad substrate, and the solder resist layer is opened to expose the pads;

[0045] Electroplating a soft gold layer onto the pads;

[0046] A photosensitive dry film is attached to the surface of the copper-clad substrate, and the photosensitive dry film is exposed and developed to expose the milled groove position;

[0047] A left-handed double-edged cutter is used to perform layered milling at the milling groove location to form a groove;

[0048] Remove the photosensitive dry film, and mill the copper-clad substrate to form a molded small board;

[0049] The molded small plates are then cleaned, inspected, and packaged.

[0050] On the other hand, the grooving method for a DDR5 product according to an embodiment of the present invention includes the following steps:

[0051] Obtain a copper-clad substrate and drill holes in the copper-clad substrate;

[0052] A circuit is fabricated on the surface of the copper-clad substrate;

[0053] A solder resist layer is formed on the surface of the copper-clad substrate, and the solder resist layer is opened to expose the pads;

[0054] A first photosensitive dry film is attached to the surface of the solder resist layer, and the first photosensitive dry film is exposed and developed to expose part of the solder pads and cover the rest of the solder pads.

[0055] The exposed portion of the solder pads is electroplated with a soft gold layer;

[0056] Remove the first photosensitive dry film and attach a second photosensitive dry film to the surface of the solder resist layer;

[0057] The second photosensitive dry film is exposed and developed to reveal the milled groove position;

[0058] A left-handed double-edged cutter is used to perform layered milling at the milling groove location to form a groove;

[0059] Remove the second photosensitive dry film, and mill the copper-clad substrate to form a molded small board;

[0060] An organic protective film is applied to the surface of the pads that are not plated with a soft gold layer;

[0061] The molded small plates are then cleaned, inspected, and packaged.

[0062] On the other hand, the grooving method for a DDR5 product according to an embodiment of the present invention includes the following steps:

[0063] Obtain a copper-clad substrate and drill holes in the copper-clad substrate;

[0064] A circuit is fabricated on the surface of the copper-clad substrate;

[0065] A solder resist layer is formed on the surface of the copper-clad substrate, and the solder resist layer is opened to expose the pads;

[0066] Electroplating a soft gold layer onto the pads;

[0067] The copper-clad substrate is split into several large boards;

[0068] Each of the large plates is individually slotted to form a groove;

[0069] Each of the large plates is milled to form several smaller shaped plates;

[0070] The molded small plates are then cleaned, inspected, and packaged.

[0071] On the other hand, the grooving method for a DDR5 product according to an embodiment of the present invention includes the following steps:

[0072] Obtain a copper-clad substrate and drill holes in the copper-clad substrate;

[0073] A circuit is fabricated on the surface of the copper-clad substrate;

[0074] A solder resist layer is formed on the surface of the copper-clad substrate, and the solder resist layer is opened to expose the pads;

[0075] A photosensitive dry film is disposed on the surface of the copper-clad substrate, and the photosensitive dry film is exposed and developed to expose part of the pads and cover the rest of the pads.

[0076] Electroplating a soft gold layer onto the exposed pads;

[0077] Remove the photosensitive dry film and separate the copper-clad substrate to form several large boards;

[0078] Each of the large plates is individually slotted to form a groove;

[0079] Each of the large plates is milled to form several smaller shaped plates;

[0080] An organic protective film is applied to the surface of the pads that are not plated with a soft gold layer;

[0081] The molded small plates are then cleaned, inspected, and packaged.

[0082] The grooving method for DDR5 products according to embodiments of the present invention has at least the following beneficial effects: by using a left-handed double-edged blade to perform layered milling on the copper-clad substrate, the grooving accuracy and quality are improved, and burrs or substrate cracking are avoided.

[0083] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0084] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0085] Figure 1 This is a flowchart illustrating the steps of a DDR5 product slotting method according to a first embodiment of the present invention.

[0086] Figure 2 This is a flowchart illustrating the steps of a DDR5 product slotting method according to a second embodiment of the present invention.

[0087] Figure 3 This is a flowchart illustrating the steps of a DDR5 product slotting method according to a third embodiment of the present invention.

[0088] Figure 4This is a flowchart illustrating the steps of a DDR5 product slotting method according to a fourth embodiment of the present invention.

[0089] Figure 5 This is a flowchart illustrating the steps of a DDR5 product slotting method according to the fifth embodiment of the present invention.

[0090] Figure 6 This is a flowchart illustrating the steps of a DDR5 product slotting method according to the sixth embodiment of the present invention. Detailed Implementation

[0091] The embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. The step numbers in the following embodiments are set only for ease of explanation, and there is no limitation on the order between the steps. The execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0092] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0093] The terms "first," "second," "third," and "fourth," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0094] In this invention, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0095] During the manufacturing process of DDR5 products, gold fingers need to be made so that the DDR5 products can make electrical connections with the motherboard. At the same time, a slot also needs to be made as the physical interface for the gold fingers. Currently, problems such as copper burrs or substrate cracking can occur during the slot manufacturing process.

[0096] To address this, this invention provides a grooving method for DDR5 products. By employing a left-handed double-edged blade, the copper-clad substrate is milled in layers, improving grooving accuracy and quality, and avoiding burrs or substrate cracking.

[0097] The grooving method of the DDR5 product according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[0098] On one hand, this invention proposes a slotting method for DDR5 products, such as... Figure 1 As shown, the method includes the following steps:

[0099] Step S100: Obtain the copper-clad substrate and drill holes in the copper-clad substrate;

[0100] Specifically, the copper-clad laminate is used for subsequent packaging substrate fabrication. Through-holes are formed on the copper-clad laminate by mechanical drilling or laser drilling. In this example, step S100 specifically includes the following four steps:

[0101] Step S110: Obtain a copper-clad substrate by cutting, baking, and Panel2D on the original substrate;

[0102] Step S120: Reduce the copper content on the surface of the copper-clad substrate;

[0103] Step S130: Perform mechanical drilling on the copper-clad substrate;

[0104] Step S140: Remove the adhesive residue generated after drilling using the Desmear process.

[0105] First, the raw substrate is cut to the required dimensions according to the design specifications. After cutting, the copper-clad laminate needs to be baked at high temperature to remove internal moisture and stress, preventing deformation (such as warping) caused by uneven heating in subsequent processes. The baking temperature is controlled at around 200℃. Next, Panel2D (two-dimensional layout design) is performed on the copper-clad laminate, including panelization rules, tooling edge optimization, and processing path optimization. Then, copper reduction is performed on the surface of the copper-clad laminate, retaining a copper thickness of 3.5±0.5μm. The copper foil thickness is reduced through chemical etching or mechanical polishing to ensure that the circuit impedance and current carrying capacity meet design requirements, avoiding impedance mismatch or uneven heat dissipation due to excessive copper layer thickness. Then, the copper-clad laminate is mechanically drilled to form several through-holes. Subsequently, the slag generated after drilling is removed using a desmear process to ensure a tight bond between the copper layer and the substrate during subsequent metallization of the hole walls. This avoids copper plating voids or delamination within the holes, resulting in a more uniform distribution of the electroplated copper layer, reducing impedance abrupt changes, and improving signal transmission stability. After removing the adhesive residue, the hole walls are metallized using the PTH process and copper plating to achieve interlayer conductivity.

[0106] Step S200: Fabricate circuits and leads on the surface of the copper-clad substrate;

[0107] Specifically, to fabricate circuitry on the surface of a copper-clad laminate (CCL), a photosensitive dry film is first attached to the surface. Then, the photosensitive dry film is exposed and developed to expose the copper layer in the areas to be etched. The exposed copper layer is then dissolved using a chemical solution to form the patterns of circuits and leads. Finally, the photosensitive dry film is removed. This method achieves the fabrication of circuits and leads. After the circuitry is fabricated, the CCL can be inspected using AOI (Automated Optical Inspection) to detect and mark any problematic circuitry.

[0108] Step S300: A solder mask layer is formed on the surface of the copper-clad substrate, and a window is made in the solder mask layer to expose the pads and leads.

[0109] Specifically, after the circuit and lead fabrication is completed, copper surface contaminants (such as oxide layers and grease) are removed through processes such as acid pickling to improve surface roughness and enhance ink adhesion. Then, solder resist ink is evenly applied to the surface of the copper-clad laminate using screen printing, spraying, or photolithography techniques. Low-temperature baking (80-100℃) removes the ink solvent, allowing the solder resist ink to form a semi-cured state. Ultraviolet light is used to pattern the solder resist ink through a film, leaving unexposed areas soluble. An alkaline solution (such as 1% Na2CO3) dissolves the uncured ink, exposing the pads and leads. Finally, high-temperature baking (150-160℃) completely hardens the solder resist layer, forming a stable insulating protective film. The solder resist layer protects non-soldering areas, restricts the flow of molten solder, and isolates moisture, dust, and chemical corrosion (such as acid and alkali fumes), preventing copper oxidation or circuit breaks on the copper-clad laminate surface and extending the lifespan of the copper-clad laminate.

[0110] Step S400: Attach a photosensitive dry film to the surface of the solder mask layer, and expose and develop the photosensitive dry film to expose the solder pads and cover the leads;

[0111] Specifically, by attaching a photosensitive dry film to the surface of the solder mask layer and exposing and developing the photosensitive dry film, the lead wires and other areas are protected by the photosensitive dry film, leaving only the solder pads exposed, which facilitates subsequent surface treatment of the solder pads.

[0112] Step S500: Electroplating a soft gold layer onto the solder pads;

[0113] Plating a soft gold layer onto the pads improves soldering reliability and supports high-precision interconnects. In this example, to improve the quality of the plated soft gold layer, the following two steps are included before step S500:

[0114] Perform soft gold pretreatment on the copper-clad substrate;

[0115] The oxide layer on the surface of the pads is removed by micro-etching.

[0116] Specifically, the oxide layer and contaminants on the surface of the solder pads are removed through processes such as pickling and micro-etching to ensure the adhesion of the electroplated layer. Then, an electrochemical deposition process is used to deposit a pure gold or gold alloy layer on the surface of the solder pads. The uniformity of the plating layer is adjusted by controlling the current density (0.5-2.0 A / dm²) and temperature (40-60℃).

[0117] Step S600: Remove the photosensitive dry film and remove the leads by alkaline etching;

[0118] After the soft gold plating layer is completed, the photosensitive dry film is removed to expose the leads. Then, the leads are removed by alkaline etching.

[0119] Step S700: Using a left-handed double-edged milling cutter, the copper-clad substrate is milled in layers to form grooves;

[0120] It should be noted that before milling the groove, the milling cutter parameters need to be optimized to reduce burrs on the groove opening. In this example, a left-hand double-edged milling cutter is used to reduce cutting resistance, improve the quality of the milled groove, and reduce chip accumulation in the machining area. Simultaneously, layered milling significantly reduces overall machining stress, preventing delamination or warping of the sheet metal, improving dimensional consistency, reducing burrs and chip residue, and enhancing milling accuracy. In this example, step S700 specifically includes the following three steps:

[0121] Step S710: Using a left-handed double-edged cutter, perform clockwise layered pre-milling grooves on the copper-clad substrate at a first rotation speed and a first milling speed;

[0122] Step S720: After completing the layered pre-milling groove, check the wear of the left-hand double-edged cutter and compensate the parameters of the left-hand double-edged cutter;

[0123] Step S730: Using the compensated left-handed double-edged cutter, perform counterclockwise fine milling grooves on the copper-clad substrate at a second rotation speed and a second milling speed; the second rotation speed is less than the first rotation speed, and the second milling speed is greater than the first milling speed.

[0124] Specifically, during pre-milling, the groove is pre-milled at a first rotational speed and a first milling speed to remove most of the material within the groove. This reduces the cutting difficulty and allowance fluctuations during the finish milling stage, resulting in more uniform stress on the finish milling tool and more accurate groove width. Simultaneously, a layered pre-milling method is employed, significantly reducing overall machining stress through multiple milling operations. This prevents sheet metal delamination or warping, improves dimensional consistency, and avoids defects such as burrs and cracks. After completing the pre-milling, the wear of the left-hand double-edged cutter is inspected. Then, based on the degree of wear, the cutter radius is compensated, resulting in higher accuracy during finish milling. It should be noted that during pre-milling, the left-hand double-edged cutter is used in a clockwise sequence with a higher rotation speed (around 42KR / min) and a lower milling speed (around 4mm / s). During finish milling, the left-hand double-edged cutter is used in a counter-clockwise sequence with a lower rotation speed (around 32KR / min) and a higher milling speed (around 6mm / s). By adjusting the rotation speed and milling speed at different stages, the milling requirements at different stages can be met, thereby improving the quality of the milled grooves. Furthermore, during layered pre-milling, the feed rate of the left-hand double-edged cutter (around 4mm / s) is less than the retraction rate (around 300mm / s), further enhancing the quality of the milled grooves.

[0125] Step S800: Mill the copper-clad substrate to form a molded small board;

[0126] After the grooving is completed, the copper-clad substrate is milled to form several small molded boards, which are used as individual products to facilitate subsequent shipment.

[0127] Step S900: Clean, inspect, and package the molded small plates.

[0128] After the milling process forms the shaped small plate, the shaped small plate is cleaned, then subjected to OQC (Outgoing Quality Control) inspection, followed by AVI, PVS and MVI inspections, and finally packaged and shipped.

[0129] According to the DDR5 product grooving method of this application embodiment, after fabricating leads and pads, the leads are covered with a photosensitive dry film, and the pads are plated with soft gold. Then, the photosensitive dry film is removed to expose the leads, thereby etching back the leads to avoid copper burrs during grooving. Then, a left-handed double-edged blade is used to perform layered milling on the copper-clad substrate to improve grooving accuracy and quality and avoid burrs or substrate cracking.

[0130] On the other hand, such as Figure 2 As shown, this application also proposes another method for slotting DDR5 products, which includes the following steps:

[0131] Step S101: Obtain the copper-clad substrate and drill holes in it;

[0132] Specifically, the process begins with material preparation, where the original substrate is cut to the required dimensions according to the design specifications. After preparation, the copper-clad laminate (CCL) is baked at high temperatures to remove internal moisture and stress, preventing deformation (such as warping) caused by uneven heating in subsequent processes. The baking temperature is controlled at approximately 200°C. Next, Panel2D (two-dimensional layout design) is performed on the CCL, including optimization of panelization rules, tooling edges, and processing paths. Then, copper is reduced on the surface of the CCL, retaining a copper thickness of 3.5±0.5μm. This reduction is achieved through chemical etching or mechanical polishing, ensuring that the circuit impedance and current carrying capacity meet design requirements, avoiding impedance mismatch or uneven heat dissipation due to excessive copper thickness. Finally, the CCL is mechanically drilled to create several through-holes. The slag generated after drilling is then removed using a desmear process, ensuring a tight bond between the copper layer and the substrate during subsequent metallization of the hole walls. This prevents copper plating voids or delamination within the holes, resulting in a more uniform copper plating distribution, reduced impedance abrupt changes, and improved signal transmission stability. After removing the adhesive residue, the hole walls are metallized using the PTH process and copper plating to achieve interlayer conductivity.

[0133] Step S201: Fabricate circuits and leads on the surface of the copper-clad substrate;

[0134] Specifically, to fabricate circuitry on the surface of a copper-clad laminate (CCL), a photosensitive dry film is first attached to the surface. Then, the photosensitive dry film is exposed and developed to expose the copper layer in the areas to be etched. The exposed copper layer is then dissolved using a chemical solution to form the patterns of circuits and leads. Finally, the photosensitive dry film is removed. This method achieves the fabrication of circuits and leads. After the circuitry is fabricated, the CCL can be inspected using AOI (Automated Optical Inspection) to detect and mark any problematic circuitry.

[0135] Step S301: A solder resist layer is formed on the surface of the copper-clad substrate, and a window is made in the solder resist layer to expose the pads and leads.

[0136] Specifically, after the circuit and lead fabrication is completed, copper surface contaminants (such as oxide layers and grease) are removed through processes such as acid pickling to improve surface roughness and enhance ink adhesion. Then, solder resist ink is evenly applied to the surface of the copper-clad laminate using screen printing, spraying, or photolithography techniques. Low-temperature baking (80-100℃) removes the ink solvent, allowing the solder resist ink to form a semi-cured state. Ultraviolet light is used to pattern the solder resist ink through a film, leaving unexposed areas soluble. An alkaline solution (such as 1% Na2CO3) dissolves the uncured ink, exposing the pads and leads. Finally, high-temperature baking (150-160℃) completely hardens the solder resist layer, forming a stable insulating protective film. The solder resist layer protects non-soldering areas, restricts the flow of molten solder, and isolates moisture, dust, and chemical corrosion (such as acid and alkali fumes), preventing copper oxidation or circuit breaks on the copper-clad laminate surface and extending the lifespan of the copper-clad laminate.

[0137] Step S401: Attach the first photosensitive dry film to the surface of the solder mask layer, and expose and develop the first photosensitive dry film to expose part of the solder pads and cover the remaining solder pads and leads.

[0138] Specifically, by attaching a first photosensitive dry film to the surface of the solder mask layer and exposing and developing the first photosensitive dry film, some of the pads that need to be electroplated with soft gold are exposed, while the first photosensitive dry film protects the leads and the pads that do not need to be electroplated with soft gold.

[0139] Step S501: Electroplat a soft gold layer onto the exposed pads;

[0140] Plating a soft gold layer onto the pads improves soldering reliability and supports high-precision interconnects. In this example, to enhance the quality of the plating, pickling and micro-etching processes are performed before plating to remove oxide layers and contaminants from the pad surface, ensuring adhesion. Then, an electrochemical deposition process is used to deposit a pure gold or gold alloy layer on the pad surface. The uniformity of the plating is adjusted by controlling the current density (0.5-2.0 A / dm²) and temperature (40-60℃).

[0141] Step S601: Remove the first photosensitive dry film and attach the second photosensitive dry film to the surface of the solder resist layer. Expose and develop the second photosensitive dry film to expose the leads.

[0142] Step S701: Remove the leads by alkaline etching and remove the second photosensitive dry film;

[0143] The remaining unplated soft gold pads are protected by the second photosensitive dry film. The second photosensitive dry film is then exposed and developed to expose the leads. The leads are then removed by alkaline etching, and the second photosensitive dry film is also removed.

[0144] Step S801: Attach a third photosensitive dry film to the surface of the solder resist layer, and expose and develop the third photosensitive dry film to expose the milled groove position;

[0145] The third photosensitive dry film protects the areas that do not need milling. Then, the third photosensitive dry film is exposed and developed to expose the areas that need milling, making it easier to mill them later. This method can effectively reduce the generation of finger burrs and avoid problems such as burrs or product scratches during milling.

[0146] Step S901: Using a left-handed double-edged cutter, perform layered milling at the slot location to form a groove;

[0147] It should be noted that before milling, the milling cutter parameters need to be optimized to reduce burrs on the groove opening. In this example, a left-hand double-edged milling cutter is used to reduce cutting resistance, improve milling quality, and reduce chip accumulation in the machining area. At the same time, by milling in layers, the overall machining stress is significantly reduced, avoiding delamination or warping of the sheet metal, improving dimensional consistency, reducing burrs and chip residue, and improving milling accuracy.

[0148] During milling, a left-handed double-edged cutter is used to perform clockwise layered pre-milling of the copper-clad substrate at a first rotational speed and a first milling speed. After completing the layered pre-milling, the wear of the left-handed double-edged cutter is detected, and the parameters of the left-handed double-edged cutter are compensated. Based on the compensated left-handed double-edged cutter, the copper-clad substrate is then fine-milled counterclockwise at a second rotational speed and a second milling speed. The second rotational speed is less than the first rotational speed, and the second milling speed is greater than the first milling speed.

[0149] Specifically, during pre-milling, the groove is pre-milled at the first rotational speed and the first milling speed to remove most of the material inside the groove. This reduces the cutting difficulty and allowance fluctuations during the finish milling stage, resulting in more uniform force on the finish milling tool and more accurate groove width. Simultaneously, a layered pre-milling method significantly reduces overall machining stress, preventing sheet metal delamination or warping, improving dimensional consistency, and avoiding defects such as burrs and cracks. After pre-milling, the wear of the left-hand double-edged cutter is checked. Then, based on the degree of wear, the cutter radius is compensated, resulting in higher accuracy during finish milling. It should be noted that during pre-milling, the left-hand double-edged cutter mills in a clockwise sequence at a higher rotational speed (around 42KR / min) and a lower milling speed (around 4mm / s); during finish milling, the left-hand double-edged cutter mills in a counter-clockwise sequence at a lower rotational speed (around 32KR / min) and a higher milling speed (around 6mm / s). By adjusting the rotational speed and milling speed at different stages, the milling requirements at different stages are met, thereby improving the quality of the milled groove. In addition, when pre-milling grooves in layers, the feed rate of the left-hand double-edged cutter (around 4 mm / s) is less than the retraction rate (around 300 mm / s), thereby further improving the quality of the milled grooves.

[0150] Step S1001: Remove the third photosensitive dry film and mill the copper-clad substrate to form a molded small board;

[0151] After milling the grooves, the third photosensitive dry film is removed, and the copper-clad substrate is milled to form several small molded boards as individual products for easy subsequent shipment.

[0152] Step S1011: Apply an organic protective film to the surface of the pads without electroplated soft gold layer;

[0153] Specifically, after applying soft gold plating to some high-frequency / high-power pads, the contact resistance can be reduced, while signal attenuation caused by oxidation can be suppressed; for other pads, an organic protective film is applied as a protective layer to prevent oxidation, maintain solderability, and reduce costs.

[0154] Step S1021: Clean, inspect and package the molded small plates.

[0155] After milling the plate to form a small slab and applying an organic protective film, the slab is cleaned and then subjected to OQC (Outgoing Quality Control) inspection, followed by AVI (Automated Visual Inspection), PVS (Product Verification Test), and MVI (Machine Vision Inspection) inspections. Finally, it is packaged and shipped.

[0156] According to the DDR5 product grooving method of this application embodiment, after fabricating leads and pads, some pads are electroplated with soft gold, and some pads are coated with an organic protective film, thereby protecting the pads while reducing costs; after plating the pads with soft gold, the second photosensitive dry film is removed to expose the leads, thereby etching back the leads to avoid copper burrs during grooving; then, a third photosensitive dry film is used to protect the areas that do not need to be grooved, exposing only the areas that need to be grooved, to avoid burrs or product scratches during grooving; finally, a left-handed double-edged blade is used to perform layered grooving on the copper-clad substrate, improving grooving accuracy and quality, and avoiding burrs or substrate cracking.

[0157] On the other hand, this application also proposes another method for slotting DDR5 products, such as... Figure 3 As shown, the method includes the following steps:

[0158] Step S102: Obtain the copper-clad substrate and drill holes in it;

[0159] Specifically, the process begins with material preparation, where the original substrate is cut to the required dimensions according to the design specifications. After preparation, the copper-clad laminate (CCL) is baked at high temperatures to remove internal moisture and stress, preventing deformation (such as warping) caused by uneven heating in subsequent processes. The baking temperature is controlled at approximately 200°C. Next, Panel2D (two-dimensional layout design) is performed on the CCL, including optimization of panelization rules, tooling edges, and processing paths. Then, copper is reduced on the surface of the CCL, retaining a copper thickness of 3.5±0.5μm. This reduction is achieved through chemical etching or mechanical polishing, ensuring that the circuit impedance and current carrying capacity meet design requirements, avoiding impedance mismatch or uneven heat dissipation due to excessive copper thickness. Finally, the CCL is mechanically drilled to create several through-holes. The slag generated after drilling is then removed using a desmear process, ensuring a tight bond between the copper layer and the substrate during subsequent metallization of the hole walls. This prevents copper plating voids or delamination within the holes, resulting in a more uniform copper plating distribution, reduced impedance abrupt changes, and improved signal transmission stability. After removing the adhesive residue, the hole walls are metallized using the PTH process and copper plating to achieve interlayer conductivity.

[0160] Step S202: Fabricate circuitry on the surface of the copper-clad substrate;

[0161] Specifically, to fabricate circuitry on the surface of a copper-clad laminate (CCL), a photosensitive dry film is first attached to the surface. Then, the photosensitive dry film is exposed and developed to expose the copper layer in the areas to be etched. The exposed copper layer is then dissolved using a chemical solution to form the circuit pattern. Finally, the photosensitive dry film is removed. This method achieves circuit fabrication. After circuit fabrication, the CCL can be inspected using AOI (Automated Optical Inspection) to detect and mark any problematic circuitry.

[0162] Step S302: A solder resist layer is formed on the surface of the copper-clad substrate, and a window is made in the solder resist layer to expose the pads;

[0163] Specifically, after the circuit fabrication is completed, processes such as acid pickling are used to remove contaminants (such as oxide layers and grease) from the copper surface, increasing surface roughness to enhance ink adhesion. Then, screen printing, spraying, or photolithography techniques are used to evenly cover the surface of the copper-clad laminate with solder resist ink. Low-temperature baking (80-100℃) removes the ink solvent, allowing the solder resist ink to form a semi-cured state. Ultraviolet light is used to pattern the solder resist ink through a film, leaving unexposed areas soluble. An alkaline solution (such as 1% Na2CO3) dissolves the uncured ink, exposing the solder pads. Finally, high-temperature baking (150-160℃) completely hardens the solder resist layer, forming a stable insulating protective film. The solder resist layer protects non-soldering areas, restricts the flow of molten solder, and isolates moisture, dust, and chemical corrosion (such as acid and alkali fumes), preventing copper oxidation or circuit breaks on the surface of the copper-clad laminate, thus extending the lifespan of the copper-clad laminate.

[0164] Step S402: Electroplating a soft gold layer onto the solder pads;

[0165] Plating a soft gold layer onto the pads improves soldering reliability and supports high-precision interconnects. In this example, to enhance the quality of the plating, pickling and micro-etching processes are performed before plating to remove oxide layers and contaminants from the pad surface, ensuring adhesion. Then, an electrochemical deposition process is used to deposit a pure gold or gold alloy layer on the pad surface. The uniformity of the plating is adjusted by controlling the current density (0.5-2.0 A / dm²) and temperature (40-60℃).

[0166] Step S502: Attach a photosensitive dry film to the surface of the copper-clad substrate, and expose and develop the photosensitive dry film to expose the milled groove position;

[0167] By using a photosensitive dry film, the areas that do not need to be milled are protected. Then, the photosensitive dry film is exposed and developed to expose the areas that need to be milled, making it easier to mill them later. This method can effectively reduce the generation of finger burrs and avoid problems such as burrs or product scratches during the milling process.

[0168] Step S602: Using a left-handed double-edged cutter, perform layered milling at the milling groove position to form a groove;

[0169] It should be noted that before milling, the milling cutter parameters need to be optimized to reduce burrs on the groove opening. In this example, a left-hand double-edged milling cutter is used to reduce cutting resistance, improve milling quality, and reduce chip accumulation in the machining area. At the same time, by milling in layers, the overall machining stress is significantly reduced, avoiding delamination or warping of the sheet metal, improving dimensional consistency, reducing burrs and chip residue, and improving milling accuracy.

[0170] During milling, a left-handed double-edged cutter is used to perform clockwise layered pre-milling of the copper-clad substrate at a first rotational speed and a first milling speed. After completing the layered pre-milling, the wear of the left-handed double-edged cutter is detected, and the parameters of the left-handed double-edged cutter are compensated. Based on the compensated left-handed double-edged cutter, the copper-clad substrate is then fine-milled counterclockwise at a second rotational speed and a second milling speed. The second rotational speed is less than the first rotational speed, and the second milling speed is greater than the first milling speed.

[0171] Specifically, during pre-milling, the groove is pre-milled at the first rotational speed and the first milling speed to remove most of the material inside the groove. This reduces the cutting difficulty and allowance fluctuations during the finish milling stage, resulting in more uniform force on the finish milling tool and more accurate groove width. Simultaneously, a layered pre-milling method significantly reduces overall machining stress, preventing sheet metal delamination or warping, improving dimensional consistency, and avoiding defects such as burrs and cracks. After pre-milling, the wear of the left-hand double-edged cutter is checked. Then, based on the degree of wear, the cutter radius is compensated, resulting in higher accuracy during finish milling. It should be noted that during pre-milling, the left-hand double-edged cutter mills in a clockwise sequence at a higher rotational speed (around 42KR / min) and a lower milling speed (around 4mm / s); during finish milling, the left-hand double-edged cutter mills in a counter-clockwise sequence at a lower rotational speed (around 32KR / min) and a higher milling speed (around 6mm / s). By adjusting the rotational speed and milling speed at different stages, the milling requirements at different stages are met, thereby improving the quality of the milled groove. In addition, when pre-milling grooves in layers, the feed rate of the left-hand double-edged cutter (around 4 mm / s) is less than the retraction rate (around 300 mm / s), thereby further improving the quality of the milled grooves.

[0172] Step S702: Remove the photosensitive dry film and mill the copper-clad substrate to form a molded small board;

[0173] After milling the grooves, the photosensitive dry film is removed, and the copper-clad substrate is milled to form several small molded boards as individual products for easy subsequent shipment.

[0174] Step S802: Clean, inspect and package the molded small plates.

[0175] After milling the plate to form a small slab and applying an organic protective film, the slab is cleaned and then subjected to OQC (Outgoing Quality Control) inspection, followed by AVI (Automated Visual Inspection), PVS (Product Verification Test), and MVI (Machine Vision Inspection) inspections. Finally, it is packaged and shipped.

[0176] According to the DDR5 product grooving method of this application embodiment, a photosensitive dry film is used to protect the areas that do not need to be grooved, exposing only the areas that need to be grooved, thus avoiding problems such as burrs or product scratches during grooving; then, a left-handed double-edged milling cutter is used to perform layered grooving on the copper-clad substrate, improving grooving accuracy and quality, and avoiding burrs or substrate cracking. This method eliminates the need for etch-back leads, improving production efficiency, but requires stricter control over the lifespan of the milling cutter.

[0177] On the other hand, this application also proposes another method for slotting DDR5 products, such as... Figure 4 As shown, the method includes the following steps:

[0178] Step S103: Obtain the copper-clad substrate and drill holes in the copper-clad substrate;

[0179] Specifically, the process begins with material preparation, where the original substrate is cut to the required dimensions according to the design specifications. After preparation, the copper-clad laminate (CCL) is baked at high temperatures to remove internal moisture and stress, preventing deformation (such as warping) caused by uneven heating in subsequent processes. The baking temperature is controlled at approximately 200°C. Next, Panel2D (two-dimensional layout design) is performed on the CCL, including optimization of panelization rules, tooling edges, and processing paths. Then, copper is reduced on the surface of the CCL, retaining a copper thickness of 3.5±0.5μm. This reduction is achieved through chemical etching or mechanical polishing, ensuring that the circuit impedance and current carrying capacity meet design requirements, avoiding impedance mismatch or uneven heat dissipation due to excessive copper thickness. Finally, the CCL is mechanically drilled to create several through-holes. The slag generated after drilling is then removed using a desmear process, ensuring a tight bond between the copper layer and the substrate during subsequent metallization of the hole walls. This prevents copper plating voids or delamination within the holes, resulting in a more uniform copper plating distribution, reduced impedance abrupt changes, and improved signal transmission stability. After removing the adhesive residue, the hole walls are metallized using the PTH process and copper plating to achieve interlayer conductivity.

[0180] Step S203: Fabricate circuitry on the surface of the copper-clad substrate;

[0181] Specifically, to fabricate circuitry on the surface of a copper-clad laminate (CCL), a photosensitive dry film is first attached to the surface. Then, the photosensitive dry film is exposed and developed to expose the copper layer in the areas to be etched. The exposed copper layer is then dissolved using a chemical solution to form the circuit pattern. Finally, the photosensitive dry film is removed. This method achieves circuit fabrication. After circuit fabrication, the CCL can be inspected using AOI (Automated Optical Inspection) to detect and mark any problematic circuitry.

[0182] Step S303: A solder resist layer is formed on the surface of the copper-clad substrate, and a window is made in the solder resist layer to expose the pads;

[0183] Specifically, after the circuit fabrication is completed, processes such as acid pickling are used to remove contaminants (such as oxide layers and grease) from the copper surface, increasing surface roughness to enhance ink adhesion. Then, screen printing, spraying, or photolithography techniques are used to evenly cover the surface of the copper-clad laminate with solder resist ink. Low-temperature baking (80-100℃) removes the ink solvent, allowing the solder resist ink to form a semi-cured state. Ultraviolet light is used to pattern the solder resist ink through a film, leaving unexposed areas soluble. An alkaline solution (such as 1% Na2CO3) dissolves the uncured ink, exposing the solder pads. Finally, high-temperature baking (150-160℃) completely hardens the solder resist layer, forming a stable insulating protective film. The solder resist layer protects non-soldering areas, restricts the flow of molten solder, and isolates moisture, dust, and chemical corrosion (such as acid and alkali fumes), preventing copper oxidation or circuit breaks on the surface of the copper-clad laminate, thus extending the lifespan of the copper-clad laminate.

[0184] Step S403: Attach the first photosensitive dry film to the surface of the solder mask layer, and expose and develop the first photosensitive dry film to expose part of the solder pads and cover the rest of the solder pads.

[0185] Specifically, by attaching a first photosensitive dry film to the surface of the solder mask layer and exposing and developing the first photosensitive dry film, some of the solder pads that need to be electroplated with soft gold are exposed, while the first photosensitive dry film protects the solder pads that do not need to be electroplated with soft gold.

[0186] Step S503: Electroplat a soft gold layer onto the exposed pads;

[0187] Plating a soft gold layer onto the pads improves soldering reliability and supports high-precision interconnects. In this example, to enhance the quality of the plating, pickling and micro-etching processes are performed before plating to remove oxide layers and contaminants from the pad surface, ensuring adhesion. Then, an electrochemical deposition process is used to deposit a pure gold or gold alloy layer on the pad surface. The uniformity of the plating is adjusted by controlling the current density (0.5-2.0 A / dm²) and temperature (40-60℃).

[0188] Step S603: Remove the first photosensitive dry film and attach the second photosensitive dry film to the surface of the solder resist layer;

[0189] Step S703: Expose and develop the second photosensitive dry film to expose the milled groove position;

[0190] The second photosensitive dry film protects the areas that do not need to be milled. Then, the second photosensitive dry film is exposed and developed to expose the areas that need to be milled, making it easier to mill them later. This method can effectively reduce the generation of finger burrs and avoid problems such as burrs or product scratches during milling.

[0191] Step S803: Using a left-handed double-edged cutter, mill a groove at the groove location to form a slot;

[0192] It should be noted that before milling, the milling cutter parameters need to be optimized to reduce burrs on the groove opening. In this example, a left-hand double-edged milling cutter is used to reduce cutting resistance, improve milling quality, and reduce chip accumulation in the machining area. At the same time, by milling in layers, the overall machining stress is significantly reduced, avoiding delamination or warping of the sheet metal, improving dimensional consistency, reducing burrs and chip residue, and improving milling accuracy.

[0193] During milling, a left-handed double-edged cutter is used to perform clockwise layered pre-milling of the copper-clad substrate at a first rotational speed and a first milling speed. After completing the layered pre-milling, the wear of the left-handed double-edged cutter is detected, and the parameters of the left-handed double-edged cutter are compensated. Based on the compensated left-handed double-edged cutter, the copper-clad substrate is then fine-milled counterclockwise at a second rotational speed and a second milling speed. The second rotational speed is less than the first rotational speed, and the second milling speed is greater than the first milling speed.

[0194] Specifically, during pre-milling, the groove is pre-milled at the first rotational speed and the first milling speed to remove most of the material inside the groove. This reduces the cutting difficulty and allowance fluctuations during the finish milling stage, resulting in more uniform force on the finish milling tool and more accurate groove width. Simultaneously, a layered pre-milling method significantly reduces overall machining stress, preventing sheet metal delamination or warping, improving dimensional consistency, and avoiding defects such as burrs and cracks. After pre-milling, the wear of the left-hand double-edged cutter is checked. Then, based on the degree of wear, the cutter radius is compensated, resulting in higher accuracy during finish milling. It should be noted that during pre-milling, the left-hand double-edged cutter mills in a clockwise sequence at a higher rotational speed (around 42KR / min) and a lower milling speed (around 4mm / s); during finish milling, the left-hand double-edged cutter mills in a counter-clockwise sequence at a lower rotational speed (around 32KR / min) and a higher milling speed (around 6mm / s). By adjusting the rotational speed and milling speed at different stages, the milling requirements at different stages are met, thereby improving the quality of the milled groove. In addition, when pre-milling grooves in layers, the feed rate of the left-hand double-edged cutter (around 4 mm / s) is less than the retraction rate (around 300 mm / s), thereby further improving the quality of the milled grooves.

[0195] Step S903: Remove the second photosensitive dry film and mill the copper-clad substrate to form a molded small board;

[0196] After milling the grooves, the second photosensitive dry film is removed, and the copper-clad substrate is milled to form several small molded boards as individual products for easy subsequent shipment.

[0197] Step S1003: Apply an organic protective film to the surface of the pads without an electroplated soft gold layer;

[0198] Specifically, after applying soft gold plating to some high-frequency / high-power pads, the contact resistance can be reduced, while signal attenuation caused by oxidation can be suppressed; for other pads, an organic protective film is applied as a protective layer to prevent oxidation, maintain solderability, and reduce costs.

[0199] Step S1013: Clean, inspect and package the molded small plates.

[0200] After milling the plate to form a small slab and applying an organic protective film, the slab is cleaned and then subjected to OQC (Outgoing Quality Control) inspection, followed by AVI (Automated Visual Inspection), PVS (Product Verification Test), and MVI (Machine Vision Inspection) inspections. Finally, it is packaged and shipped.

[0201] According to the DDR5 product slotting method of this application embodiment, after fabricating the pads, some pads are electroplated with soft gold, and some pads are coated with an organic protective film, thereby protecting the pads while reducing costs. A second photosensitive dry film is used to protect the areas that do not need to be milled, exposing only the areas that need to be milled, avoiding problems such as burrs or product scratches during slotting. Then, a left-handed double-edged milling cutter is used to perform layered slotting on the copper-clad substrate, improving the slotting accuracy and quality, and avoiding burrs or substrate cracking. This method eliminates the need for etch-back leads, which can improve production efficiency, but the lifespan control of the milling cutter needs to be more stringent.

[0202] On the other hand, this application also proposes another method for slotting DDR5 products, such as... Figure 5 As shown, the method includes the following steps:

[0203] Step S104: Obtain the copper-clad substrate and drill holes in it;

[0204] Specifically, the process begins with material preparation, where the original substrate is cut to the required dimensions according to the design specifications. After preparation, the copper-clad laminate (CCL) is baked at high temperatures to remove internal moisture and stress, preventing deformation (such as warping) caused by uneven heating in subsequent processes. The baking temperature is controlled at approximately 200°C. Next, Panel2D (two-dimensional layout design) is performed on the CCL, including optimization of panelization rules, tooling edges, and processing paths. Then, copper is reduced on the surface of the CCL, retaining a copper thickness of 3.5±0.5μm. This reduction is achieved through chemical etching or mechanical polishing, ensuring that the circuit impedance and current carrying capacity meet design requirements, avoiding impedance mismatch or uneven heat dissipation due to excessive copper thickness. Finally, the CCL is mechanically drilled to create several through-holes. The slag generated after drilling is then removed using a desmear process, ensuring a tight bond between the copper layer and the substrate during subsequent metallization of the hole walls. This prevents copper plating voids or delamination within the holes, resulting in a more uniform copper plating distribution, reduced impedance abrupt changes, and improved signal transmission stability. After removing the adhesive residue, the hole walls are metallized using the PTH process and copper plating to achieve interlayer conductivity.

[0205] Step S204: Fabricate circuitry on the surface of the copper-clad substrate;

[0206] Specifically, to fabricate circuitry on the surface of a copper-clad laminate (CCL), a photosensitive dry film is first attached to the surface. Then, the photosensitive dry film is exposed and developed to expose the copper layer in the areas to be etched. The exposed copper layer is then dissolved using a chemical solution to form the circuit pattern. Finally, the photosensitive dry film is removed. This method achieves circuit fabrication. After circuit fabrication, the CCL can be inspected using AOI (Automated Optical Inspection) to detect and mark any problematic circuitry.

[0207] Step S304: A solder resist layer is formed on the surface of the copper-clad substrate, and a window is made in the solder resist layer to expose the pads;

[0208] Specifically, after the circuit fabrication is completed, processes such as acid pickling are used to remove contaminants (such as oxide layers and grease) from the copper surface, increasing surface roughness to enhance ink adhesion. Then, screen printing, spraying, or photolithography techniques are used to evenly cover the surface of the copper-clad laminate with solder resist ink. Low-temperature baking (80-100℃) removes the ink solvent, allowing the solder resist ink to form a semi-cured state. Ultraviolet light is used to pattern the solder resist ink through a film, leaving unexposed areas soluble. An alkaline solution (such as 1% Na2CO3) dissolves the uncured ink, exposing the solder pads. Finally, high-temperature baking (150-160℃) completely hardens the solder resist layer, forming a stable insulating protective film. The solder resist layer protects non-soldering areas, restricts the flow of molten solder, and isolates moisture, dust, and chemical corrosion (such as acid and alkali fumes), preventing copper oxidation or circuit breaks on the surface of the copper-clad laminate, thus extending the lifespan of the copper-clad laminate.

[0209] Step S404: Electroplating a soft gold layer onto the solder pads;

[0210] Plating a soft gold layer onto the pads improves soldering reliability and supports high-precision interconnects. In this example, to enhance the quality of the plating, pickling and micro-etching processes are performed before plating to remove oxide layers and contaminants from the pad surface, ensuring adhesion. Then, an electrochemical deposition process is used to deposit a pure gold or gold alloy layer on the pad surface. The uniformity of the plating is adjusted by controlling the current density (0.5-2.0 A / dm²) and temperature (40-60℃).

[0211] Step S504: Separate the copper-clad substrate into several large boards;

[0212] The copper-clad substrate is divided into two large boards, which makes it easier to punch grooves on the two large boards separately, thereby reducing the area occupied by the copper-clad substrate and making subsequent processing easier.

[0213] Step S604: Punch grooves into each large plate to form slots;

[0214] Each large plate is individually slotted using a CNC grooving machine or other CNC equipment to create the required grooves.

[0215] Step S704: Mill each large plate to form several shaped small plates;

[0216] After the grooving is completed, the large plate is milled to form several small plates, which are then used as individual products for subsequent shipment.

[0217] Step S804: Clean, inspect and package the molded small plates.

[0218] The process involves milling the plate to form a small shaped plate, cleaning the shaped plate, then performing OQC (Outgoing Quality Control) inspection, followed by AVI (Automated Visual Inspection), PVS (Product Verification Test), and MVI (Machine Vision Inspection) inspections, before finally packaging and shipping.

[0219] According to the DDR5 product slotting method of the present application embodiment, the copper-clad substrate is first divided into large boards, and then each large board is directly slotted to form the required slots, thereby improving the slotting efficiency and reducing the cost.

[0220] On the other hand, this application also proposes another method for slotting DDR5 products, such as... Figure 6 As shown, the method includes the following steps:

[0221] Step S105: Obtain the copper-clad substrate and drill holes in it;

[0222] Specifically, the process begins with material preparation, where the original substrate is cut to the required dimensions according to the design specifications. After preparation, the copper-clad laminate (CCL) is baked at high temperatures to remove internal moisture and stress, preventing deformation (such as warping) caused by uneven heating in subsequent processes. The baking temperature is controlled at approximately 200°C. Next, Panel2D (two-dimensional layout design) is performed on the CCL, including optimization of panelization rules, tooling edges, and processing paths. Then, copper is reduced on the surface of the CCL, retaining a copper thickness of 3.5±0.5μm. This reduction is achieved through chemical etching or mechanical polishing, ensuring that the circuit impedance and current carrying capacity meet design requirements, avoiding impedance mismatch or uneven heat dissipation due to excessive copper thickness. Finally, the CCL is mechanically drilled to create several through-holes. The slag generated after drilling is then removed using a desmear process, ensuring a tight bond between the copper layer and the substrate during subsequent metallization of the hole walls. This prevents copper plating voids or delamination within the holes, resulting in a more uniform copper plating distribution, reduced impedance abrupt changes, and improved signal transmission stability. After removing the adhesive residue, the hole walls are metallized using the PTH process and copper plating to achieve interlayer conductivity.

[0223] Step S205: Fabricate circuitry on the surface of the copper-clad substrate;

[0224] Specifically, to fabricate circuitry on the surface of a copper-clad laminate (CCL), a photosensitive dry film is first attached to the surface. Then, the photosensitive dry film is exposed and developed to expose the copper layer in the areas to be etched. The exposed copper layer is then dissolved using a chemical solution to form the circuit pattern. Finally, the photosensitive dry film is removed. This method achieves circuit fabrication. After circuit fabrication, the CCL can be inspected using AOI (Automated Optical Inspection) to detect and mark any problematic circuitry.

[0225] Step S305: A solder resist layer is formed on the surface of the copper-clad substrate, and a window is made in the solder resist layer to expose the pads;

[0226] Specifically, after the circuit fabrication is completed, processes such as acid pickling are used to remove contaminants (such as oxide layers and grease) from the copper surface, increasing surface roughness to enhance ink adhesion. Then, screen printing, spraying, or photolithography techniques are used to evenly cover the surface of the copper-clad laminate with solder resist ink. Low-temperature baking (80-100℃) removes the ink solvent, allowing the solder resist ink to form a semi-cured state. Ultraviolet light is used to pattern the solder resist ink through a film, leaving unexposed areas soluble. An alkaline solution (such as 1% Na2CO3) dissolves the uncured ink, exposing the solder pads. Finally, high-temperature baking (150-160℃) completely hardens the solder resist layer, forming a stable insulating protective film. The solder resist layer protects non-soldering areas, restricts the flow of molten solder, and isolates moisture, dust, and chemical corrosion (such as acid and alkali fumes), preventing copper oxidation or circuit breaks on the surface of the copper-clad laminate, thus extending the lifespan of the copper-clad laminate.

[0227] Step S405: A photosensitive dry film is deposited on the surface of the copper-clad substrate, and the photosensitive dry film is exposed and developed to expose part of the pads and cover the rest of the pads.

[0228] Specifically, by attaching a photosensitive dry film to the surface of the solder mask layer and exposing and developing the photosensitive dry film, some of the solder pads that need to be electroplated with soft gold are exposed, while the photosensitive dry film protects the solder pads that do not need to be electroplated with soft gold.

[0229] Step S505: Electroplat a soft gold layer onto the exposed pads;

[0230] Plating a soft gold layer onto the pads improves soldering reliability and supports high-precision interconnects. In this example, to enhance the quality of the plating, pickling and micro-etching processes are performed before plating to remove oxide layers and contaminants from the pad surface, ensuring adhesion. Then, an electrochemical deposition process is used to deposit a pure gold or gold alloy layer on the pad surface. The uniformity of the plating is adjusted by controlling the current density (0.5-2.0 A / dm²) and temperature (40-60℃).

[0231] Step S605: Remove the photosensitive dry film and separate the copper-clad substrate into several large boards;

[0232] The copper-clad substrate is divided into two large boards, which makes it easier to punch grooves on the two large boards separately, thereby reducing the area occupied by the copper-clad substrate and making subsequent processing easier.

[0233] Step S705: Punch grooves into each large plate to form slots;

[0234] Each large plate is individually slotted using a CNC grooving machine or other CNC equipment to create the required grooves.

[0235] Step S805: Mill each large plate to form several smaller shaped plates;

[0236] After the grooving is completed, the large plate is milled to form several small plates, which are then used as individual products for subsequent shipment.

[0237] Step S905: Apply an organic protective film to the surface of the pads that are not plated with a soft gold layer;

[0238] Specifically, after applying soft gold plating to some high-frequency / high-power pads, the contact resistance can be reduced, while signal attenuation caused by oxidation can be suppressed; for other pads, an organic protective film is applied as a protective layer to prevent oxidation, maintain solderability, and reduce costs.

[0239] Step S1005: Clean, inspect and package the molded small plates.

[0240] The process involves milling the plate to form a small shaped plate, cleaning the shaped plate, then performing OQC (Outgoing Quality Control) inspection, followed by AVI (Automated Visual Inspection), PVS (Product Verification Test), and MVI (Machine Vision Inspection) inspections, before finally packaging and shipping.

[0241] According to the DDR5 product slotting method of this application embodiment, the copper-clad substrate is first split into large boards, and then each large board is directly slotted to form the required slots, thereby improving slotting efficiency and reducing costs. Soft gold plating is applied to some pads, and an organic protective film is applied to others, thereby protecting the pads while reducing costs.

[0242] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for slotting a DDR5 product, characterized in that, Includes the following steps: Obtain a copper-clad substrate and drill holes in the copper-clad substrate; Lines and leads are fabricated on the surface of the copper-clad substrate; A solder resist layer is formed on the surface of the copper-clad substrate, and a window is made in the solder resist layer to expose the pads and the leads; A photosensitive dry film is attached to the surface of the solder mask layer, and the photosensitive dry film is exposed and developed to expose the solder pads and cover the leads. Electroplating a soft gold layer onto the pads; Remove the photosensitive dry film and remove the leads by alkaline etching; A left-handed double-edged milling cutter is used to mill grooves in layers on the copper-clad substrate to form grooves; The copper-clad substrate is milled to form a molded small board; The molded small plates are cleaned, inspected, and packaged; The method of using a left-handed double-edged milling cutter to mill grooves in layers on the copper-clad substrate to form grooves includes: Using the left-handed double-edged cutter, the copper-clad substrate is pre-milled clockwise with a first rotational speed and a first milling speed to create a layered pre-milling groove. After completing the layered pre-milling groove, the wear of the left-handed double-edged cutter is detected, and the parameters of the left-handed double-edged cutter are compensated. The copper-clad substrate is precision-milled counterclockwise using a compensated left-handed double-edged cutter at a second rotational speed and a second milling speed; the second rotational speed is less than the first rotational speed, and the second milling speed is greater than the first milling speed.

2. The grooving method for a DDR5 product according to claim 1, characterized in that, The process of obtaining the copper-clad substrate and drilling holes in the copper-clad substrate includes: The copper-clad substrate is obtained by cutting, baking, and two-dimensional layout design of the original substrate; The copper content of the copper-clad substrate is reduced. Mechanical drilling is performed on the copper-clad substrate; The Desmear process removes the adhesive residue generated after drilling.

3. The grooving method for a DDR5 product according to claim 1, characterized in that, Before electroplating the soft gold layer onto the solder pads, the process further includes: The copper-clad substrate is subjected to a soft gold pretreatment. The oxide layer on the surface of the pads is removed by micro-etching.

4. The grooving method for a DDR5 product according to claim 1, characterized in that, When milling grooves, the feed rate of the left-handed double-edged cutter is less than the retraction rate.

5. A method for slotting a DDR5 product, characterized in that, Includes the following steps: Obtain a copper-clad substrate and drill holes in the copper-clad substrate; Lines and leads are fabricated on the surface of the copper-clad substrate; A solder resist layer is formed on the surface of the copper-clad substrate, and a window is made in the solder resist layer to expose the pads and the leads; A first photosensitive dry film is attached to the surface of the solder mask layer, and the first photosensitive dry film is exposed and developed to expose part of the solder pads and cover the remaining solder pads and leads; The exposed portion of the solder pads is electroplated with a soft gold layer; Remove the first photosensitive dry film, and attach a second photosensitive dry film to the surface of the solder resist layer. Expose and develop the second photosensitive dry film to expose the lead wire. The leads are removed by alkaline etching, and the second photosensitive dry film is also removed. A third photosensitive dry film is attached to the surface of the solder resist layer, and the third photosensitive dry film is exposed and developed to reveal the milled groove position; A left-handed double-edged cutter is used to perform layered milling at the milling groove location to form a groove; Remove the third photosensitive dry film, and mill the copper-clad substrate to form a molded small board; An organic protective film is applied to the surface of the pads that are not plated with a soft gold layer; The molded small plates are cleaned, inspected, and packaged; The method of using a left-handed double-edged cutter to perform layered milling at the milling groove location to form a groove includes: Using the left-handed double-edged cutter, the copper-clad substrate is pre-milled clockwise with a first rotational speed and a first milling speed; After completing the layered pre-milling groove, the wear of the left-handed double-edged cutter is detected, and the parameters of the left-handed double-edged cutter are compensated. The copper-clad substrate is precision-milled counterclockwise using a compensated left-handed double-edged cutter at a second rotational speed and a second milling speed; the second rotational speed is less than the first rotational speed, and the second milling speed is greater than the first milling speed.

6. A method for slotting a DDR5 product, characterized in that, Includes the following steps: Obtain a copper-clad substrate and drill holes in the copper-clad substrate; Lines are fabricated on the surface of the copper-clad substrate; A solder resist layer is formed on the surface of the copper-clad substrate, and the solder resist layer is opened to expose the pads. Electroplating a soft gold layer onto the pads; A photosensitive dry film is attached to the surface of the copper-clad substrate, and the photosensitive dry film is exposed and developed to expose the milled groove position; A left-handed double-edged cutter is used to perform layered milling at the milling groove location to form a groove; Remove the photosensitive dry film, and mill the copper-clad substrate to form a molded small board; The molded small plates are cleaned, inspected, and packaged; The method of using a left-handed double-edged cutter to perform layered milling at the milling groove location to form a groove includes: Using the left-handed double-edged cutter, the copper-clad substrate is pre-milled clockwise with a first rotational speed and a first milling speed; After completing the layered pre-milling groove, the wear of the left-handed double-edged cutter is detected, and the parameters of the left-handed double-edged cutter are compensated. The copper-clad substrate is precision-milled counterclockwise using a compensated left-handed double-edged cutter at a second rotational speed and a second milling speed; the second rotational speed is less than the first rotational speed, and the second milling speed is greater than the first milling speed.

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