Laser windowing method for small round hole in thick copper foil of AMB substrate
Through the combination method of dry film direct exposure and dry film laser engraving window opening process, the problem of making small-sized process holes on thick copper foil is solved, efficient and accurate small-hole etching is achieved, and the product functional requirements of AMB substrates are met.
Patent Information
- Application Number
- CN202510149258.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-11
- Publication Date
- 2025-06-17
AI Technical Summary
The prior art is difficult to efficiently etch small-sized process small round holes on thick copper foils, especially due to the resolution limitation of the exposure machine, it is impossible to effectively produce small holes that meet product requirements.
The combination method of dry film direct exposure and dry film laser engraving window opening process is adopted. The film graphic design does not set small process holes, but aligned MARK dot patterns. The laser engraving process is used to carve window opening on the dry film, and then etch it on thick copper foil to form small round holes.
It effectively solves the problem of making small-sized process holes on thick copper foil, improves the accuracy and quality of small holes, and meets product functional requirements.
Smart Images
Figure CN120155667A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of semiconductor technology, specifically to a method for copper foil windowing. Background Art
[0002] Due to the need to have high and low temperature shock reliability and carry large currents, the copper foil of the AMB substrate is required to be relatively thick, with a thickness exceeding 0.50 mm. Due to the product function requirements, small-sized process small holes are opened on the thick copper foil. However, when making these small holes, according to the current direct exposure process, it is very difficult to etch the small holes in this thick copper. Taking 0.50 mm copper thickness as an example, the minimum requirement for the product drawing size of the small hole is a diameter of 0.60 mm. When designing the film drawing, considering the side etching factor, it is necessary to reduce the small hole size, and the minimum requirement for the small hole diameter is 0.13 mm, while the minimum resolution of the exposure machine is 0.18 mm, exceeding the working ability of the exposure machine, and it is impossible to expose the small holes on the film to the dry film. Therefore, it is somewhat difficult to make these small holes by the traditional direct exposure process. Summary of the Invention
[0003] Aiming at the problems existing in the prior art, the present invention provides a method for laser windowing of small holes on the thick copper foil of the AMB substrate to solve at least one of the above technical problems.
[0004] To achieve the above purpose, the present invention provides a method for laser windowing of small holes on the thick copper foil of the AMB substrate, which is characterized by including the following steps:
[0005] Step 1, film pattern design, no process small holes are set on the film pattern, and alignment MARK point patterns are set on the film pattern;
[0006] Step 2, after the film pattern undergoes the exposure and development processes, it is displayed on the dry film;
[0007] Step 3, rely on the alignment MARK points formed on the dry film for positioning, and use the laser engraving process to engrave and open small holes on the dry film;
[0008] Step 4, etching. When etching, small holes are formed in the corresponding small hole engraving and opening area on the dry film on the thick copper foil.
[0009] The present invention can solve the problem of making small-sized process holes on thick copper foil through the combination of dry film direct exposure and dry film laser engraving windowing processes.
[0010] Further preferably, the thickness of the thick copper foil is 0.5 mm - 0.8 mm.
[0011] Further preferably, the alignment MARK point patterns are located in the opposite corner regions of the film pattern.
[0012] Further preferably, in step three, the diameter of the small hole engraved window is 0.07 mm to 0.10 mm.
[0013] Further preferably, when the thickness of the thick copper foil is 0.5 mm, in step three, the diameter of the small hole engraved window is 0.07 mm to 0.10 mm, and in step four, the diameter of the small round hole is 0.55 mm to 0.62 mm;
[0014] When the thickness of the thick copper foil is 0.6 mm, in step three, the diameter of the small hole engraved window is 0.07 mm to 0.10 mm, and in step four, the diameter of the small round hole is 0.65 mm to 0.73 mm;
[0015] When the thickness of the thick copper foil is 0.7 mm, in step three, the diameter of the small hole engraved window is 0.07 mm to 0.10 mm, and in step four, the diameter of the small round hole is 0.76 mm to 0.82 mm;
[0016] When the thickness of the thick copper foil is 0.8 mm, in step three, the diameter of the small hole engraved window is 0.07 mm to 0.10 mm, and in step four, the diameter of the small round hole is 0.88 mm to 0.93 mm.
[0017] Further preferably, in step three, in the laser engraving process, the engraving power is 70 - 85%, the engraving frequency is 40 - 60 kHz; the engraving speed is 460 - 530 mm / s; the pulse width is 3 - 5 μs; the number of engraving times is 3 - 5 times; the engraving time is 0.05 - 0.2 ms.
[0018] Further preferably, in step two, the thickness of the dry film is 10 μm - 100 μm.
[0019] Further preferably, in step two, during exposure, the exposure energy is 40 - 100 J / cm 2 , and the wavelength of the exposure treatment is 360 nm to 410 nm.
[0020] Further preferably, in step two, during development, a weakly alkaline solution is used for development, the temperature is 20 - 50 °C, and the development time is 1 min - 5 min;
[0021] The weakly alkaline solution is a 0.5 - 1.5 wt% sodium carbonate solution or potassium carbonate solution.
[0022] Further preferably, in step four, during etching, a mixed solution of 10 - 30 wt% hydrogen peroxide and 10 - 30 wt% sodium chlorate is used for etching, the etching temperature is 20 - 50 °C, and the etching time is 5 - 16 min.
[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: The production of small holes is changed from the direct exposure process of dry film to the combination of direct exposure and dry film laser engraving for window opening, solving the problem of producing small-sized process holes on thick copper foils. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 It is a flowchart of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0025] The present invention will be further described below with reference to the accompanying drawings.
[0026] See Figure 1 , Specific Embodiment 1: A method for laser window opening of small round holes on a thick copper foil of an AMB substrate, comprising the following steps:
[0027] Step 1, film pattern design. Process small holes are not provided on the film pattern, and alignment MARK point patterns are provided on the film pattern;
[0028] Step 2, after the film pattern is exposed and developed, it is displayed on the dry film;
[0029] Step 3, rely on the alignment MARK points formed on the dry film for positioning, and use the laser engraving process to engrave and open small holes on the dry film;
[0030] Step 4, etching. When etching, small round holes are formed in the area corresponding to the small hole engraving and window opening area on the thick copper foil on the dry film.
[0031] Through the combination of the dry film direct exposure and the dry film laser engraving and window opening process, the present invention can solve the problem of producing small-sized process holes on thick copper foils.
[0032] The thickness of the thick copper foil is 0.5 mm - 0.8 mm.
[0033] The alignment MARK point patterns are located in the opposite corner regions of the film pattern.
[0034] In Step 3, the diameter of the small hole engraving and window opening is 0.07 mm to 0.10 mm.
[0035] When the thickness of the thick copper foil is 0.5 mm, in Step 3, the diameter of the small hole engraving and window opening is 0.07 mm to 0.10 mm, and in Step 4, the diameter of the small round hole is 0.55 mm to 0.62 mm.
[0036] When the thickness of the thick copper foil is 0.6 mm, in Step 3, the diameter of the small hole engraving and window opening is 0.07 mm to 0.10 mm, and in Step 4, the diameter of the small round hole is 0.65 mm to 0.73 mm.
[0037] When the thickness of the thick copper foil is 0.7 mm, in Step 3, the diameter of the small hole engraving window is 0.07 mm to 0.10 mm, and in Step 4, the diameter of the small round hole is 0.76 mm to 0.82 mm.
[0038] When the thickness of the thick copper foil is 0.8 mm, in Step 3, the diameter of the small hole engraving window is 0.07 mm to 0.10 mm, and in Step 4, the diameter of the small round hole is 0.88 mm to 0.93 mm.
[0039] The size of the small hole laser window is as follows in the table:
[0040]
[0041] In Step 3, in the laser engraving process, the engraving power is 70 - 85%, the engraving frequency is 40 - 60 kHz; the engraving speed is 460 - 530 mm / s; the pulse width is 3 - 5 μs; the number of engraving times is 3 - 5 times; the engraving time is 0.05 - 0.2 ms.
[0042] In Step 2, the thickness of the dry film is 10 μm - 100 μm.
[0043] In Step 2, during exposure, the exposure energy is 40 - 100 J / cm 2 , and the wavelength of the exposure treatment is 360 nm to 410 nm.
[0044] In Step 2, during development, a weakly alkaline solution is used for development, the temperature is 20 - 50 °C, and the development time is 1 min - 5 min; the weakly alkaline solution is a 0.5 - 1.5 wt% sodium carbonate solution or potassium carbonate solution.
[0045] In Step 4, during etching, a mixed solution of 10 - 30 wt% hydrogen peroxide and 10 - 30 wt% sodium chlorate is used for etching, the etching temperature is 20 - 50 °C, and the etching time is 5 - 16 min.
[0046] The above is only the preferred implementation mode of the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle of the present invention, several improvements and retouches can be made, and these improvements and retouches should also be regarded as the protection scope of the present invention.
Claims
1. A method for laser windowing of small circular holes on thick copper foil of AMB substrate, characterized in that: The steps include: Step 1: Film pattern design. No process holes are set on the film pattern, but a registration mark point pattern is set on the film pattern. Step 2: The film pattern is displayed on the dry film after exposure and development process; Step 3: Positioning is performed based on the alignment mark points formed on the dry film, and small holes are carved and opened on the dry film using a laser engraving process; Step 4: Etching. During etching, small circular holes are formed in the thick copper foil corresponding to the small hole carving window area on the dry film.
2. The method for laser windowing of small circular holes on thick copper foil of AMB substrate according to claim 1, characterized in that: The thickness of the thick copper foil is 0.5 mm to 0.8 mm.
3. The method for laser opening small circular holes on thick copper foil of AMB substrate according to claim 1, characterized in that: The alignment MARK dot pattern is located at opposite corner areas of the film pattern.
4. The method for laser windowing of small circular holes on thick copper foil of AMB substrate according to claim 1, characterized in that: In step three, the diameter of the small hole engraving window is 0.07mm to 0.10mm.
5. The method for laser opening small circular holes on thick copper foil of AMB substrate according to claim 1, characterized in that: When the thickness of the thick copper foil is 0.5 mm, in step 3, the diameter of the small hole engraving window is 0.07 mm to 0.10 mm, and in step 4, the diameter of the small round hole is 0.55 mm to 0.62 mm; When the thickness of the thick copper foil is 0.6 mm, in step 3, the diameter of the small hole engraving window is 0.07 mm to 0.10 mm, and in step 4, the diameter of the small round hole is 0.65 mm to 0.73 mm; When the thickness of the thick copper foil is 0.7 mm, in step 3, the diameter of the small hole engraving window is 0.07 mm to 0.10 mm, and in step 4, the diameter of the small round hole is 0.76 mm to 0.82 mm; When the thickness of the thick copper foil is 0.8 mm, in step three, the diameter of the small hole engraved window is 0.07 mm to 0.10 mm, and in step four, the diameter of the small round hole is 0.88 mm to 0.93 mm.
6. The method for laser opening small circular holes on thick copper foil of AMB substrate according to claim 1, characterized in that: In step three, in the laser engraving process, the engraving power is 70-85%, the engraving frequency is 40-60 kHz; the engraving speed is 460-530 mm / s; the pulse width is 3-5 μs; the number of engraving times is 3-5 times; and the engraving time is 0.05-0.2 ms.
7. The method for laser opening small circular holes on thick copper foil of AMB substrate according to claim 1, characterized in that: In step 2, the thickness of the dry film is 10 μm-100 μm.
8. The method for laser opening small circular holes on thick copper foil of AMB substrate according to claim 1, characterized in that: In step 2, the exposure energy is 40-100 J / cm 2 The wavelength of exposure treatment is 360nm~410nm.
9. The method for laser opening small circular holes on thick copper foil of AMB substrate according to claim 1, characterized in that: In step 2, during development, a weak alkaline solution is used for development at a temperature of 20-50° C. and a development time of 1 min-5 min; The weak alkaline solution is a 0.5-1.5 wt % sodium carbonate solution or a potassium carbonate solution.
10. The method for laser opening small circular holes on thick copper foil of AMB substrate according to claim 1, characterized in that: In step 4, a mixed solution of 10-30 wt % hydrogen peroxide and 10-30 wt % sodium chlorate is used for etching, the etching temperature is 20-50° C., and the etching time is 5-16 min.