Processing method of FCCSP packaging substrate solder mask small window

Abstract

The invention relates to the technical field of basic packaging, in particular to an FCCSP packaging substrate resistance welding small window processing method, which is characterized in that size compensation is carried out on a window during resistance welding exposure, so that the size of the window after development is smaller than a preset difference value of the size of the target window, a reasonable space is reserved for laser accurate correction in the subsequent step, and the yield of the FCCSP packaging substrate is improved. And the problems of easy size deviation and irregular shape of the small windowing in the traditional exposure and development process are effectively solved. The printing ink at the windowing edge is ablated through laser drilling equipment according to preset parameters, hole patterns can be accurately modified, the windowing size can be strictly controlled to be a target value, compared with traditional chemical etching and laser machining, the size precision is higher, the edge is more regular, the high-precision requirement for the small windowing of the packaging substrate under the chip microminiaturization trend can be met, and the production efficiency is improved. And the reliability of butt joint of welding spots during subsequent chip packaging is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of basic packaging, in particular to a processing method for a solder resist small opening of an FCCSP packaging substrate. BACKGROUND

[0002] In the FC (flip chip) packaging system, BOP and BOL (Bottom Over Lead) are two main packaging structure forms. The BOP type occupies an important position in the application of FCCSP packaging substrates (especially in the packaging of high-performance chips such as application processors) because it can better adapt to the demand for high-density packaging. At present, the conventional design capability of FCCSP substrate BOP type products in the industry is that the BumpPitch (bump pitch) is 130 μm, and the corresponding solder resist opening SRO (Solder Resist Opening) size is 75 μm. Within this size range, the industry generally uses dry film type ink (such as dry film ink of type AUS410, SR1) to carry out solder resist processing. The upper limit of the thickness of this type of ink is usually 15 μm, which can basically meet the requirements of opening precision and ink adhesion for conventional packaging.

[0003] With the development of miniaturization and high performance of electronic equipment, terminal customers have higher demands for the packaging density of FCCSP substrates, and the market has gradually emerged product demands for BumpPitch of 120 μm and 110 μm. The matching solder resist opening SRO size needs to be reduced to 60 μm and 50 μm at the same time. However, the existing solder resist processing technology based on dry film type ink has significant technical bottlenecks when facing such small size opening demands. On the one hand, due to the limitation of the uniformity of the thickness of the dry film type ink, the ink layer in the small opening area is prone to local over-thickness or under-thickness, which directly affects the size control in the subsequent exposure and development stages. On the other hand, the alignment accuracy of traditional exposure equipment (such as using non-segmented or low-precision segmented exposure method) and the spraying uniformity and time control accuracy of development equipment are difficult to adapt to the processing requirements of small openings (60 μm and below) - exposure is prone to opening area deviation, and after development, there are often opening size deviations (such as local over-thickness or under-thickness), irregular shapes (such as edge burrs, inconsistent hole diameters), and incomplete development (residual ink in the opening) and other problems. The above defects will directly lead to the misalignment of the subsequent chip bump and substrate BumpPAD, causing problems such as poor welding, reduced signal transmission stability, etc., which cannot meet the use requirements of customers for high-precision packaging, and has become a key obstacle to the development of FCCSP substrates to smaller pitch and smaller opening. SUMMARY

[0004] To address the aforementioned issues, a method for processing small openings in the solder resist of an FCCSP packaging substrate is provided. By compensating for the size of the openings during solder resist exposure, the size of the openings after development is made smaller than the preset difference of the target opening size. This provides reasonable space for precise laser correction in subsequent steps, effectively solving the problems of easy deviation in the size and irregular shape of small openings in traditional exposure and development processes. To address the problems of existing technologies, this invention provides a method for processing small solder resist openings on an FCCSP package substrate, comprising the following steps: S1. Before solder masking, an ultra-roughening solution is used to etch the copper layer on the circuit surface, and the amount of micro-etching is controlled to form a preset roughness on the copper layer surface of the packaging substrate.

[0005] S2. A vacuum laminator is used to press dry film ink onto the circuit surface of the packaging substrate, so that the dry film ink completely covers the circuit.

[0006] S3. Use an exposure device to expose the solder resist on the packaging substrate. During exposure, perform size compensation on the solder resist opening so that the opening size after development is smaller than the preset difference of the target opening size.

[0007] S4. Develop the exposed packaging substrate to obtain a semi-finished packaging substrate that meets the preset size range.

[0008] S5. The semi-finished packaging substrate after UV curing and development is tested to ensure that the ink curing degree meets the standard.

[0009] S6. The cured semi-finished packaging substrate is cured at high temperature, and the ink thermosetting degree is tested to ensure that it meets the standard. S7. Use acid pickling solution to clean the surface of the packaging substrate to remove impurities from the surface; S8. Use a laser drilling machine to perform laser ablation on the packaging substrate, set the opening size to be consistent with the target opening size according to the preset parameters; control the laser parameters to ablate the ink at the edge of the opening, modify the hole shape and process the size to the target opening size to complete the processing.

[0010] The laser drilling equipment used in step S8 includes a processing component for performing laser ablation on the packaging substrate and a worktable for placing the packaging substrate. A cavity is provided under the worktable, which is connected to an external suction mechanism. The surface of the worktable is provided with multiple vent holes that communicate with the cavity, and the multiple vent holes are arranged in a rectangular array. A positioning mechanism is also provided on the worktable. The positioning mechanism includes a first positioning component and a second positioning component symmetrically distributed on both sides of the worktable. Both the first positioning component and the second positioning component are provided with scissor frames that can be extended along the edge direction of the packaging substrate. Multiple positioning heads are provided on the scissor frames that are evenly spaced, and the multiple positioning heads can slide vertically toward the packaging substrate to fix the packaging substrate.

[0011] Preferably, the cavity of the workbench is provided with a plurality of independent air chambers, each of which is provided with an air outlet communicated with an external air suction mechanism, and each of which is provided with a valve.

[0012] Preferably, the cavity is in a cylindrical structure as a whole, and the plurality of independent air chambers are in a fan-shaped structure with equal volumes.

[0013] Preferably, the first positioning assembly and the second positioning assembly each include a mounting frame extending in a horizontal direction, both ends of the mounting frame are provided with a driving block capable of sliding along the length direction thereof, and the two driving blocks are capable of sliding relative to each other, the middle part of the scissor frame is hinged to the mounting frame, and both ends of the scissor frame are hinged to the two driving blocks, respectively.

[0014] Preferably, the mounting frame is provided with a first screw rod extending along the length direction thereof, the screw threads at both ends of the first screw rod are opposite in rotation direction, the end part of the mounting frame is provided with a first rotary driving motor for driving the first screw rod to rotate, and the two driving blocks are respectively sleeved on both ends of the first screw rod and cooperated with the screw threads at the corresponding positions.

[0015] Preferably, the first positioning assembly and the second positioning assembly are each provided with a fixing frame corresponding to the number of positioning heads, the fixing frame on the first positioning assembly is provided with a spray head, the spray head is communicated with an external inert gas supply source, and the gas outlet end of the spray head is in a fan-shaped structure for spraying inert gas to the region to be processed of the packaging substrate.

[0016] Preferably, the fixing frame on the second positioning assembly is provided with a suction port communicated with an external negative pressure recovery device, and the opening direction of the suction port is adapted to the gas jetting direction of the spray head on the first positioning assembly, for recovering the debris generated by laser ablation.

[0017] Preferably, the positioning mechanism further includes a driving assembly for driving the first positioning assembly and the second positioning assembly to slide relative to each other.

[0018] Preferably, the positioning head is mounted on the fixing frame and is elastically connected to the fixing frame, the fixing frame is provided with a sensor for monitoring the position of the positioning head, the sensor is signal-connected to the control end of the external inert gas supply source, and when the sensor monitors that the positioning head moves to a preset fixed position, the external inert gas supply source is triggered to deliver inert gas to the spray head.

[0019] The beneficial effects of the present application compared with the prior art are: The application makes size compensation to the window during solder mask exposure, so that the window size after development is smaller than the target window size by a preset difference value, and reasonable space is reserved for subsequent laser accurate correction, effectively solving the problems of easy deviation of small window size and irregular shape in traditional exposure and development process; the laser drilling equipment ablates the ink at the edge of the window according to the preset parameters, which can accurately modify the hole type and strictly control the window size to the target value, compared with traditional chemical etching, the size precision of laser processing is higher and the edge is more regular, which can meet the high precision demand of small window of the packaging substrate under the trend of chip miniaturization, and ensure the reliability of solder joint docking during subsequent chip packaging. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a three-dimensional structural schematic diagram of a laser drilling equipment in a processing method of a small window of a solder mask of an FCCSP packaging substrate.

[0021] Figure 2 It is a top view of a laser drilling equipment in a processing method of a small window of a solder mask of an FCCSP packaging substrate.

[0022] Figure 3 It is a front view of a laser drilling equipment in a processing method of a small window of a solder mask of an FCCSP packaging substrate.

[0023] Figure 4 It is a three-dimensional structural schematic diagram of a workbench in a processing method of a small window of a solder mask of an FCCSP packaging substrate Figure 1 .

[0024] Figure 5 It is a three-dimensional structural schematic diagram of a workbench in a processing method of a small window of a solder mask of an FCCSP packaging substrate Figure 2 .

[0025] Figure 6 It is an enlarged view of A in Figure 5 .

[0026] Figure 7 It is a three-dimensional structural schematic diagram of a workbench in a processing method of a small window of a solder mask of an FCCSP packaging substrate

[0027] Figure 8 It is an enlarged view of B in Figure 7 .

[0028] Figure 9 It is a three-dimensional structural schematic diagram of a first positioning assembly in a processing method of a small window of a solder mask of an FCCSP packaging substrate.

[0029] Figure 10 It is a three-dimensional structural schematic diagram of a second positioning assembly in a processing method of a small window of a solder mask of an FCCSP packaging substrate.

[0030] The diagram is labeled as follows: 1. Laser drilling equipment; 11. Processing component; 12. Worktable; 121. Cavity; 1211. Air chamber; 12111. Air outlet; 12112. Valve; 1212. Vent hole; 13. Positioning mechanism; 131. First positioning component; 1311. Scissor lift; 1312. Positioning head; 1313. Mounting bracket; 13131. Drive block; 13132. First lead screw; 13133. First rotary drive motor; 1314. Fixing bracket; 13141. Nozzle; 132. Second positioning component; 1321. Air intake; 133. Drive component; 134. Sensor; 2. Packaging substrate. Detailed Implementation

[0031] To further understand the features, technical means, and specific objectives and functions achieved by the present invention, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0032] like Figures 1 to 3 The following is a method for processing a small solder mask opening on an FCCSP package substrate, comprising the following steps: S1. Before solder resist etching, the copper layer on the circuit surface is etched with an ultra-roughening chemical solution to control the amount of micro-etching so that the copper layer surface of the packaging substrate 2 forms a preset roughness.

[0033] S2. A vacuum laminator is used to press the dry film ink onto the circuit surface of the packaging substrate 2, so that the dry film ink completely covers the circuit.

[0034] S3. The solder resist of the packaging substrate 2 is exposed using an exposure device. During exposure, the size of the solder resist opening is compensated so that the opening size after development is smaller than the preset difference of the target opening size.

[0035] S4. Develop the exposed packaging substrate 2 to obtain a semi-finished packaging substrate 2 that meets the preset size range.

[0036] S5. The semi-finished packaging substrate 2 after UV curing and development is tested to ensure that the ink curing degree meets the standard.

[0037] S6. The cured semi-finished packaging substrate 2 is cured at high temperature, and the ink thermosetting degree is tested to ensure that it meets the standard.

[0038] S7. Clean the surface of the packaging substrate 2 with acid pickling solution to remove impurities from the surface.

[0039] S8. Use laser drilling equipment 1 to perform laser ablation on the packaging substrate 2, set the opening size to be consistent with the target opening size according to the preset parameters; control the laser parameters to ablate the ink at the edge of the opening, modify the hole shape and process the size to the target opening size, and complete the processing.

[0040] Step S1 etches the surface copper layer of the circuit by super roughing chemical solution and controls the micro-etching amount, so that the surface of the copper layer of the packaging substrate 2 forms a preset roughness, which can significantly improve the adhesion between the dry film type ink and the copper layer in step S2, avoid the ink from falling off or warping during the film pressing, curing and subsequent laser processing, and lay a foundation for stable processing of the solder mask window.

[0041] From the perspective of precision control core, step S3 compensates the size of the window during solder mask exposure, so that the size of the window after development is smaller than the target window size by a preset difference, which reserves a reasonable space for the subsequent laser precision correction in step S8, effectively solving the problems of easy deviation of small window size and irregular shape in traditional exposure and development process; step S8 ablates the ink at the edge of the window by laser drilling equipment 1 according to preset parameters, which can not only accurately modify the hole type, but also strictly control the size of the window to the target value. Compared with traditional chemical etching, laser processing has higher size precision and more regular edge, which can meet the high precision requirement of small window of packaging substrate 2 under the trend of chip miniaturization, and ensure the reliability of solder joint docking in subsequent chip packaging.

[0042] From the perspective of processing stability and quality assurance, steps S5 and S6 adopt a dual curing process of UV light curing combined with high temperature curing, and ensure that the ink curing degree meets the standard through detection, which can greatly improve the weather resistance, insulation and impact resistance of the ink layer, and avoid cracking and performance degradation of the packaging substrate 2 due to insufficient ink curing in subsequent use; step S7 removes impurities on the surface of the board by cleaning the surface with acid pickling solution, which can eliminate the influence of surface pollutants on laser ablation precision and prevent problems such as window edge burr and incomplete ablation caused by impurities, further ensuring the quality of the window.

[0043] Both the pre-treatment and the dual curing ensure the stability of the processing basis, and the combination of exposure compensation and laser correction breaks through the precision bottleneck of small window, while avoiding the problem of heavy metal pollution in traditional chemical etching process. At the same time of improving the processing precision, product yield and reliability of the solder mask small window of the packaging substrate 2, it also takes into account the environmental protection and production practicability, which can adapt to the development needs of FCCSP packaging substrate 2 to finer circuits.

[0044] As Figures 1 to 6The laser drilling equipment 1 used in step S8 includes a machining assembly 11 for performing laser ablation on the packaging substrate 2 and a workbench 12 for placing the packaging substrate 2; the workbench 12 is provided with a cavity 121 below, the cavity 121 is communicated with an external suction mechanism, the surface of the workbench 12 is provided with a plurality of air holes 1212 communicated with the cavity 121, and the plurality of air holes 1212 are arranged in a rectangular array; the workbench 12 is also provided with a positioning mechanism 13, the positioning mechanism 13 includes a first positioning assembly 131 and a second positioning assembly 132 symmetrically distributed on both sides of the workbench 12, and the first positioning assembly 131 and the second positioning assembly 132 are both provided with a scissor frame 1311 capable of unfolding along the edge direction of the packaging substrate 2, and the scissor frame 1311 is provided with a plurality of equally spaced positioning heads 1312, and the plurality of positioning heads 1312 can slide along the vertical direction to the packaging substrate 2 to fix the packaging substrate 2.

[0045] By placing the packaging substrate 2 to be processed on the surface of the workbench 12, the external suction mechanism communicated with the cavity 121 is started, and a negative pressure is formed through the cavity 121 and the plurality of air holes 1212 on the surface of the workbench 12. Since the plurality of air holes 1212 are arranged in a rectangular array, a uniform and stable negative pressure adsorption force can be formed on the lower surface of the packaging substrate 2. This uniform stress mode not only realizes the preliminary fixation of the packaging substrate 2, but also avoids the uneven stress problem of the packaging substrate 2 caused by traditional local adsorption, and fundamentally reduces the warping of the packaging substrate 2 caused by excessive local stress. At the same time, the first positioning assembly 131 and the second positioning assembly 132 symmetrically distributed on the workbench 12 will start to act, and the scissor frame 1311 on the first positioning assembly 131 and the second positioning assembly 132 will unfold along the edge direction of the packaging substrate 2 to adapt to the edge length of the packaging substrate 2. Without replacing the positioning components, it can meet the needs of various specifications, improving the compatibility of the equipment; after the scissor frame 1311 is unfolded to align with the edge length of the packaging substrate 2, the plurality of equally spaced positioning heads 1312 on the scissor frame 1311 will slide along the vertical direction to the surface of the packaging substrate 2 until they are pressed against the edge of the packaging substrate 2, forming a uniform downward pressure on the edge of the packaging substrate 2. This uniform downward pressure combined with the uniform adsorption of the workbench 12 forms a double fixation mechanism, which not only avoids displacement of the packaging substrate 2 during laser ablation by stable fixation, but also further suppresses the warping trend of the packaging substrate 2 by uniform stress, ensuring that the packaging substrate 2 always remains flat. The uniform downward pressure can also prevent surface damage to the packaging substrate 2 caused by excessive local pressure, ensuring processing quality, and the synergistic effect of the overall structure ultimately improves the size accuracy and hole type regularity of the solder resist small window, while the operation is convenient, which helps to improve the processing efficiency. Subsequently, the machining assembly 11 of the laser drilling equipment 1 is started to perform laser ablation on the fixed packaging substrate 2, and the solder resist small window is precisely processed.

[0046] like Figures 1 to 5 and Figure 7 As shown: The workbench 12 has multiple independent air chambers 1211 in its cavity 121. Each air chamber 1211 is provided with an air outlet 12111 that communicates with an external air intake mechanism, and each air outlet 12111 is equipped with a valve 12112.

[0047] Multiple independent air chambers 1211 within the cavity 121 of the workbench 12 are connected to an external suction mechanism via their respective air outlets 12111. When the external suction mechanism is activated, the negative pressure intensity of the corresponding air chamber 1211 can be adjusted by controlling the opening and closing of the valve 12112 at each air outlet 12111. For different warped areas of the packaging substrate 2, the adsorption intensity of the corresponding area can be adjusted to match it. Through this independent control method, the vent holes 1212 in different areas of the workbench 12 can generate adsorption forces that match the regional characteristics of the packaging substrate 2, achieving precise and differentiated fixation of the packaging substrate 2. Overcoming the limitations of traditional integral cavities 121 that cannot adjust local adsorption force, this design allows for customized adsorption force in different areas based on the structural characteristics of the packaging substrate 2. This avoids deformation or circuit damage to the packaging substrate 2 caused by excessive local adsorption force, while ensuring the stability of areas requiring strong fixation. Precise control of negative pressure is achieved by adjusting the opening of valves 12112, making adsorption force adjustment more flexible and adaptable to the processing requirements of packaging substrates 2 with different process needs, thus improving equipment adaptability. The independent air chambers 1211 ensure that the adsorption functions of each area are independent. Even if individual air chambers 1211 or vents 1212 become blocked, other air chambers 1211 can still operate normally, reducing overall processing interruptions caused by local failures and improving the stability and fault tolerance of equipment operation. Furthermore, this structure can meet the fixation requirements of various packaging substrates 2 without changing the worktable 12, reducing tooling change time and contributing to improved overall processing efficiency.

[0048] like Figures 1 to 5 and Figure 7 As shown: the cavity 121 has an overall cylindrical structure, and the multiple independent air chambers 1211 are all fan-shaped structures with equal volume.

[0049] The cavity 121 is in a cylindrical structure as a whole, and a plurality of fan-shaped air chambers 1211 are distributed radially from the center to the edge of the cavity 121. Since the packaging substrate 2 is usually rectangular in structure and is usually placed in the central area of the workbench 12, the distribution pattern of the fan-shaped air chambers 1211 can naturally adapt to the outline of the rectangular packaging substrate 2, and the fan-shaped area extending from the center can completely cover each part of the rectangular packaging substrate 2, avoiding the problem of incomplete coverage that may occur due to the mismatch between the area division and the edge of the rectangular packaging substrate 2 when the air chambers 1211 are arranged in a rectangular array. When the packaging substrate 2 is locally warped, the fan-shaped air chambers 1211 in the corresponding area can be independently controlled: if a corner or an edge of the packaging substrate 2 is warped, only the fan-shaped air chambers 1211 under the part need to be adjusted to increase the suction force, and the suction force of the adjacent air chambers 1211 can be fine-tuned as needed, and the force generated by the differential negative pressure is used to guide the packaging substrate 2 to be flat; and since the plurality of fan-shaped air chambers 1211 are radially distributed from the center to the outside, no matter where the packaging substrate 2 is warped, the corresponding fan-shaped air chamber 1211 can be found for accurate control. Compared with the rectangular array air chamber 1211 which is fixed due to area division and is difficult to flexibly match the warped part of the rectangular packaging substrate 2, this structure can more efficiently correct the warping of the packaging substrate 2 through suction adjustment and ensure that the packaging substrate 2 remains flat during laser ablation.

[0050] As shown in Figures 1 to 3 , Figure 5 , Figure 6 , Figures 8 to 10 The first positioning assembly 131 and the second positioning assembly 132 each include a mounting frame 1313 extending in the horizontal direction, both ends of the mounting frame 1313 are provided with a driving block 13131 that can slide along the length direction thereof, and the two driving blocks 13131 can slide relative to each other. The middle part of the scissor frame 1311 is hinged to the mounting frame 1313, and both ends of the scissor frame 1311 are hinged to the two driving blocks 13131, respectively.

[0051] When it is necessary to adjust the unfolding amplitude of the scissor frame 1311 to adapt to packaging substrates 2 of different sizes, the driving blocks 13131 at both ends of the mounting frame 1313 slide relative to each other along the length direction of the mounting frame 1313. Since the middle part of the scissor frame 1311 is hinged to the mounting frame 1313, and both ends of the scissor frame 1311 are hinged to the two driving blocks 13131, respectively, the sliding of the driving blocks 13131 will drive the scissor frame 1311 to unfold or contract with the middle hinge point as the fulcrum. When the driving blocks 13131 move closer to each other, the scissor frame 1311 contracts; when the driving blocks 13131 move away from each other, the scissor frame 1311 unfolds, thereby synchronously adjusting the positions of the plurality of positioning heads 1312 on the scissor frame 1311, so that the positioning heads 1312 can accurately align the edges of the packaging substrate 2.

[0052] The mounting frame 1313 provides a stable support base for the driving blocks 13131 and the scissor frame 1311. The driving blocks 13131 are fixed along the sliding track of the mounting frame 1313 in the length direction, ensuring that the unfolding and shrinking process of the scissor frame 1311 is stable and controllable in direction, avoiding the deviation of the positioning head 1312. The scissor frame 1311 is hinged at the middle part to the mounting frame 1313 and hinged at both ends to the two driving blocks 13131, forming a stable linkage relationship between the unfolding range of the scissor frame 1311 and the sliding distance of the driving blocks 13131, so as to realize the precise unfolding of the scissor frame 1311 by controlling the sliding accuracy of the driving blocks 13131, and ensure that the positioning head 1312 can be uniformly aligned with the edge of the packaging substrate 2. The relative sliding of the two driving blocks 13131 makes the unfolding range of the scissor frame 1311 flexible to adjust, which can adapt to packaging substrates 2 of different lengths or widths, and improve the compatibility of the positioning mechanism 13 for packaging substrates 2 of various specifications. At the same time, the force transmission of this hinged structure is more uniform, which can reduce the stress concentration when the scissor frame 1311 is unfolded, prolong the service life of the mechanism, and the overall structure is simple, which is convenient for assembly and maintenance, and helps to improve the positioning efficiency and stability, and provides reliable protection for the stable fixation of the packaging substrate 2 during laser ablation.

[0053] As shown in Figures 1 to 3 , Figure 5 , Figure 6 , Figures 8 to 10 , the mounting frame 1313 is provided with a first screw rod 13132 extending along the length direction thereof, the threads at both ends of the first screw rod 13132 are opposite in rotation direction, and the end part of the mounting frame 1313 is provided with a first rotary driving motor 13133 for driving the rotation of the first screw rod 13132, and the two driving blocks 13131 are respectively sleeved on both ends of the first screw rod 13132 and cooperated with the threads at the corresponding positions.

[0054] When the first rotary driving motor 13133 is started and drives the rotation of the first screw rod 13132, due to the opposite rotation direction of the threads at both ends of the first screw rod 13132 and the cooperation of the two driving blocks 13131 with the threads at both ends of the first screw rod 13132, the rotation of the first screw rod 13132 will be converted into the relative movement of the two driving blocks 13131 along the length direction of the mounting frame 1313. This relative movement drives the scissor frame 1311 to realize unfolding or shrinking with the middle hinge point as the fulcrum through the hinged relationship between the driving blocks 13131 and both ends of the scissor frame 1311, so as to accurately adjust the alignment position of the positioning head 1312 and the edge of the packaging substrate 2.

[0055] The first screw rod 13132 is in threaded cooperation with the driving blocks 13131, has high precision, can accurately control the sliding distance of the two driving blocks 13131, and then accurately adjust the unfolding range of the scissors frame 1311, so as to ensure that the positioning head 1312 can be stably aligned with the edges of the packaging substrate 2 of different sizes; the first screw rod 13132 is arranged with opposite screw directions at both ends, so that the movements of the two driving blocks 13131 are completely synchronized, avoiding the tilting of the scissors frame 1311 or the deviation of the positioning head 1312 due to asynchronous driving, and ensuring the balanced force of the positioning mechanism 13; the structure of the first rotary driving motor 13133 directly driving the screw rod is compact and has high transmission efficiency, can quickly respond to the unfolding or shrinking demand of the scissors frame 1311, shorten the positioning adjustment time, and improve the processing efficiency; at the same time, the self-locking property of the threaded transmission can make the driving blocks 13131 maintain a stable position when stopping moving, avoid loosening of the scissors frame 1311 due to external force, and ensure that the packaging substrate 2 is always in a stable positioning state during the laser ablation process, thereby providing reliable protection for high-precision processing of small windowed solder resist.

[0056] As shown in Figures 1 to 3 , Figure 5 , Figure 6 , Figures 8 to 10 , the first positioning assembly 131 and the second positioning assembly 132 are each provided with a fixed frame 1314 corresponding to the number of positioning heads 1312 thereof; the fixed frame 1314 on the first positioning assembly 131 is provided with a spray head 13141, the spray head 13141 is in communication with an external inert gas supply source, and the gas outlet end of the spray head 13141 is in a fan-shaped structure for spraying inert gas to the to-be-processed area of the packaging substrate 2.

[0057] By arranging the same number of fixed frames 1314 as the positioning heads 1312 on the first positioning assembly 131 and the second positioning assembly 132, it can be ensured that each fixed frame 1314 and the spray head 13141 thereon always matches the position of the corresponding positioning head 1312, and then forms a stable distance with the edge and the to-be-processed area of the packaging substrate 2. When the scissors frame 1311 of the first positioning assembly 131 and the second positioning assembly 132 is unfolded along the edge of the packaging substrate 2, the positioning head 1312 is lowered to press against the packaging substrate 2 after fixing, and the external inert gas supply source delivers inert gas to the spray head 13141 on the fixed frame 1314 of the first positioning assembly 131; since the gas outlet end of the spray head 13141 is in a fan-shaped structure, the inert gas will form a uniform fan-shaped gas flow covering the laser ablation area of the packaging substrate 2 when sprayed, and the inert gas will be continuously sprayed during the laser ablation process, which not only isolates the contact between air and the to-be-processed area of the packaging substrate 2, but also guides the debris generated by ablation to move in a preset direction, thereby forming cooperation with the overall processing process.

[0058] By the correspondence of the fixing frame 1314 and the positioning head 1312, the misalignment of the nozzle 13141 due to position deviation and the packaging substrate 2 to be processed can be avoided, ensuring that the inert gas can act accurately on the area that needs to be protected, eliminating the protection blind area caused by the fixed position of the traditional nozzle 13141; the fan-shaped structure of the nozzle 13141 can expand the coverage range of the inert gas, compared with the conventional circular nozzle 13141, the gas can be more evenly distributed in the ablation point and the surrounding area, preventing oxidation or debris residue in the local area due to insufficient gas coverage, improving the protection effect; at the same time, the nozzle 13141 is directly connected with the external inert gas supply source, which can ensure the continuity and stability of the gas supply, and the jet action can be synchronized with the timing of positioning and laser ablation, reducing the waiting time of the processing link, assisting to improve the debris cleaning efficiency, further ensuring the edge regularity of the small opening window and the processing quality of the packaging substrate 2, especially suitable for the processing scene of the small opening window dense area of the packaging substrate 2.

[0059] As shown in Figures 1 to 3 , Figure 5 , Figure 6 , Figures 8 to 10 : The fixing frame 1314 on the second positioning assembly 132 is provided with an air suction port 1321, the air suction port 1321 is connected with the external negative pressure recovery device, and the opening direction of the air suction port 1321 is matched with the jet direction of the nozzle 13141 on the first positioning assembly 131, which is used for recovering the debris generated by laser ablation.

[0060] The air suction port 1321 on the fixing frame 1314 of the second positioning assembly 132 can be accurately aligned with the edge of the packaging substrate 2 and the vicinity of the laser ablation area by adjusting the position of the positioning head 1312; when the external negative pressure recovery device is started, a stable negative pressure is formed at the air suction port 1321, and because the opening direction of the air suction port 1321 is matched with the jet direction of the nozzle 13141 on the first positioning assembly 131, the inert gas sprayed by the nozzle 13141 of the first positioning assembly 131 can direct the debris generated by laser ablation to the direction of the air suction port 1321, forming a synergistic path of jet flow guiding and negative pressure recovery; during the process of the positioning head 1312 pressing and fixing the packaging substrate 2, the air suction port 1321 always maintains a stable distance with the ablation area, ensuring that the negative pressure can effectively cover the debris generation range, and the debris is sucked into the air suction port 1321 and transported to the external negative pressure recovery device, realizing the centralized collection of the debris.

[0061] The suction port 1321 is adapted in direction with the nozzle 13141, avoiding the problem of insufficient efficiency in traditional single jet cleaning or single suction recovery. Through the synergy of airflow directional guidance and negative pressure adsorption, the thoroughness of debris recovery is greatly improved, and the debris residues in the surface of the packaging substrate 2 or the gap of the workbench 12 are reduced. The suction port 1321 relies on the fixed frame 1314 corresponding to the positioning head 1312, and can adapt to packaging substrates 2 of different sizes through the expansion and contraction of the scissor frame 1311, and always accurately aligns the periphery of the ablation area, ensuring that no matter how the size of the packaging substrate 2 changes, the debris can be quickly recovered after being generated, avoiding the accumulation of debris due to the deviation of the recovery position. Stable negative pressure recovery can prevent debris from adhering to the lens of the laser processing assembly 11 or the windowed edge of the packaging substrate 2, reducing processing defects such as ablation burrs, window size deviation, and other processing defects caused by debris interference, and ensuring the edge regularity and processing precision of the solder mask small window. At the same time, the centralized recovery of debris also reduces the workload of subsequent cleaning of the workbench 12.

[0062] As shown in Figures 1 to 3 , Figure 5 , Figure 6 , Figures 8 to 10 The positioning mechanism 13 further includes a driving assembly 133 for driving the first positioning assembly 131 and the second positioning assembly 132 to slide relative to each other.

[0063] When placing packaging substrates 2 of different sizes, the driving assembly 133 starts and drives the first positioning assembly 131 and the second positioning assembly 132 to slide relatively along the preset direction of the workbench 12, the driving assembly 133 drives the first positioning assembly 131 and the second positioning assembly 132 to move close to each other to reduce the distance, until the distance between the first positioning assembly 131 and the second positioning assembly 132 matches the corresponding size of the packaging substrate 2; then, the scissors frame 1311 of the first positioning assembly 131 and the second positioning assembly 132 is further expanded along the edge of the packaging substrate 2, so that the positioning head 1312 precisely presses against the edge of the packaging substrate 2 to complete the fixation, forming a two-stage positioning logic of overall distance adjustment and local expansion of the scissors frame 1311. This breaks through the limitation that the first positioning assembly 131 and the second positioning assembly 132 can only adapt to a single size of the packaging substrate 2 when the positions are fixed, and can cover a wider range of specifications of the packaging substrate 2, greatly improving the versatility of the positioning mechanism 13; the relative sliding realized by the driving assembly 133 has stable guidance, ensuring that the first positioning assembly 131 and the second positioning assembly 132 always move along the preset direction, avoiding asymmetric positioning due to deviation, and ensuring that the forces on both sides of the packaging substrate 2 are balanced; the synergy of relative sliding and expansion of the scissors frame 1311 enables the positioning mechanism 13 to quickly adapt to the overall size of the packaging substrate 2, and also adapt to the detailed profile of the edge of the packaging substrate 2 through local adjustment of the scissors frame 1311, improving positioning accuracy; at the same time, this structure does not need manual replacement of positioning tools, and the distance adjustment can be automatically completed by the driving assembly 133, reducing the changeover time and helping to improve the efficiency of batch processing, especially suitable for multi-variety and small-batch production scenarios.

[0064] As shown in Figures 1 to 3 , Figure 5 , Figure 6 , Figures 8 to 10 Figures 1 to 3 Figure 5 Figure 6 Figures 8 to 10 , the positioning head 1312 is installed on the fixed frame 1314, and the positioning head 1312 is elastically connected with the fixed frame 1314, the fixed frame 1314 is provided with a sensor 134 for monitoring the position of the positioning head 1312, the sensor 134 is signal connected with the control end of the external inert gas supply source, when the sensor 134 detects that the positioning head 1312 moves to the preset fixed position, the external inert gas supply source is triggered to deliver inert gas to the nozzle 13141.

[0065] The positioning head 1312 is installed on the fixed frame 1314 by an elastic connection mode, when the scissors frame 1311 of the first positioning assembly 131 is unfolded, and the positioning head 1312 slides along the vertical direction to the surface of the packaging substrate 2, the elastic connection can provide a buffer for the pressing action of the positioning head 1312, avoiding the surface damage caused by the direct rigid contact between the positioning head 1312 and the packaging substrate 2; at the same time, the sensor 134 on the fixed frame 1314 can monitor the position change of the positioning head 1312 in real time, when the positioning head 1312 slides down to contact the surface of the packaging substrate 2 and reaches the preset fixed pressure, the sensor 134 immediately sends a trigger signal to the control end of the external inert gas source, so that the inert gas source starts and delivers gas to the nozzle 13141 on the fixed frame 1314, the fan-shaped nozzle 13141 immediately sprays inert gas to the packaging substrate 2 to be processed, replacing the traditional manual control or fixed time control mode, ensuring that the inert gas is sprayed at the first time of positioning, avoiding the waste of gas caused by early spraying, and preventing the oxidation of the packaging substrate 2 to be processed caused by late spraying, improving the gas utilization efficiency and protection timeliness; the positioning and protection functions form a closed loop, without additional manual intervention or multi-step operation, simplifying the processing process and reducing human operation errors.

[0066] The above embodiments only express one or several embodiments of the present application, and the description is more specific and detailed, but it cannot be understood as the limitation of the protection scope of the present application. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A method for processing small solder mask openings on an FCCSP packaging substrate, characterized in that, Includes the following steps: S1. Before solder resist etching, the copper layer on the circuit surface is etched with an ultra-roughening chemical solution to control the amount of micro-etching so that the copper layer surface of the packaging substrate (2) forms a preset roughness. S2. A vacuum laminator is used to press the dry film ink onto the circuit surface of the packaging substrate (2) so that the dry film ink completely covers the circuit. S3. Use an exposure device to expose the solder resist on the packaging substrate (2). During exposure, compensate for the size of the solder resist opening so that the opening size after development is smaller than the preset difference of the target opening size. S4. Develop the exposed packaging substrate (2) to obtain a semi-finished packaging substrate (2) that conforms to the preset size range. S5. The semi-finished packaging substrate (2) after UV curing and development is tested to ensure that the ink curing degree meets the standard. S6. The cured semi-finished packaging substrate (2) is cured at high temperature, and the ink thermosetting degree is tested to ensure that it meets the standard. S7. Clean the surface of the packaging substrate (2) with acid pickling solution to remove impurities from the surface; S8. Use a laser drilling device (1) to laser ablate the packaging substrate (2), set the opening size to be consistent with the target opening size according to the preset parameters; control the laser parameters to ablate the ink on the edge of the opening, modify the hole shape and process the size to the target opening size, and complete the processing.

2. The processing method for a small solder resist opening on an FCCSP packaging substrate according to claim 1, characterized in that, The laser drilling equipment (1) used in step S8 includes a processing assembly (11) for performing laser ablation on the packaged substrate (2) and a worktable (12) for placing the packaged substrate (2). A cavity (121) is provided below the workbench (12), the cavity (121) is connected to the external air intake mechanism, and the surface of the workbench (12) is provided with multiple air vents (1212) that are connected to the cavity (121), and the multiple air vents (1212) are arranged in a rectangular array. The workbench (12) is also provided with a positioning mechanism (13). The positioning mechanism (13) includes a first positioning component (131) and a second positioning component (132) symmetrically distributed on both sides of the workbench (12). The first positioning component (131) and the second positioning component (132) are each provided with a scissor bracket (1311) that can be unfolded along the edge direction of the packaging substrate (2). The scissor bracket (1311) is provided with a plurality of positioning heads (1312) arranged at equal intervals. The plurality of positioning heads (1312) can slide along the vertical direction toward the packaging substrate (2) to fix the packaging substrate (2).

3. The method for processing a small solder mask opening on an FCCSP packaging substrate according to claim 2, characterized in that, The workbench (12) has multiple independent air chambers (1211) in its cavity (121). Each air chamber (1211) is provided with an air outlet (12111) that is connected to an external air intake mechanism, and each air outlet (12111) is equipped with a valve (12112).

4. The processing method for a small solder resist opening on an FCCSP packaging substrate according to claim 3, characterized in that, The cavity (121) has a cylindrical structure, and the multiple independent air chambers (1211) are all fan-shaped structures with equal volume.

5. The processing method for a small solder mask opening on an FCCSP packaging substrate according to claim 1, characterized in that, The first positioning component (131) and the second positioning component (132) both include a mounting bracket (1313) extending in the horizontal direction. Both ends of the mounting bracket (1313) are provided with drive blocks (13131) that can slide along its length direction, and the two drive blocks (13131) can slide relative to each other. The middle part of the scissor lift (1311) is hinged to the mounting bracket (1313), and both ends of the scissor lift (1311) are respectively hinged to the two drive blocks (13131).

6. The method for processing a small solder mask opening on an FCCSP packaging substrate according to claim 5, characterized in that, The mounting bracket (1313) is provided with a first lead screw (13132) extending along its length. The threads at both ends of the first lead screw (13132) are turned in opposite directions. The end of the mounting bracket (1313) is provided with a first rotary drive motor (13133) for driving the first lead screw (13132) to rotate. Two drive blocks (13131) are respectively sleeved on both ends of the first lead screw (13132) and form a fit with the threads at the corresponding positions.

7. The method for processing a small solder mask opening on an FCCSP packaging substrate according to claim 1, characterized in that, The first positioning component (131) and the second positioning component (132) are each provided with a fixed frame (1314) that is the same number as and corresponds one-to-one with its own positioning head (1312). The fixed frame (1314) on the first positioning component (131) is equipped with a nozzle (13141). The nozzle (13141) is connected to an external inert gas supply source, and the outlet end of the nozzle (13141) has a fan-shaped structure, which is used to spray inert gas into the processing area of ​​the packaging substrate (2).

8. The method for processing a small solder mask opening on an FCCSP packaging substrate according to claim 7, characterized in that, The second positioning component (132) has an air intake (1321) installed on the bracket (1314). The air intake (1321) is connected to the external negative pressure recovery device, and the opening direction of the air intake (1321) is adapted to the jet direction of the nozzle (13141) on the first positioning component (131) for recovering the debris generated by laser ablation.

9. A method for processing a small solder mask opening on an FCCSP packaging substrate according to claim 1, characterized in that, The positioning mechanism (13) also includes a drive component (133) for driving the first positioning component (131) and the second positioning component (132) to slide relative to each other.

10. A method for processing a small solder mask opening on an FCCSP packaging substrate according to claim 7, characterized in that, The positioning head (1312) is mounted on the fixed frame (1314) and is elastically connected to the fixed frame (1314). The fixed frame (1314) is equipped with a sensor (134) for monitoring the position of the positioning head (1312). The sensor (134) is connected to the control terminal of the external inert gas supply source. When the sensor (134) detects that the positioning head (1312) has moved to the preset fixed position, it triggers the external inert gas supply source to deliver inert gas to the nozzle (13141).

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