A method for manufacturing a six-layer high-frequency mixed-voltage circuit board

Abstract

The present invention provides a method for manufacturing a six-layer high-frequency hybrid circuit board, comprising the following steps: inner layer → lamination → ceramic grinding → primary dry film → primary micro-etching and copper reduction → primary resin grinding → primary drilling → primary electroplating → resin plugging → secondary resin grinding → secondary micro-etching and copper reduction → tertiary resin grinding → secondary electroplating → outer layer dry film → outer layer etching → AOI → solder mask → secondary drilling → profiling → testing → AVI → nickel-palladium-gold (NPG) → packaging. During the primary dry film step, the L6 surface is fully covered with dry film and exposed without removing the protective film. Both the primary and secondary micro-etching and copper reduction steps utilize an etching machine for copper reduction. This improves the manufacturing process, enhances copper reduction uniformity, prevents resin exposure at the surface plugging and capping, and enhances the quality of the hybrid circuit board.

Description

Technical Field

[0001] The present invention relates to the field of circuit board processing, and in particular to a method for manufacturing a six-layer high-frequency mixed-voltage circuit board. Background Art

[0002] The Chinese patent application, published as CN 110337200 A on October 15, 2019, discloses a method for manufacturing a high-frequency, mixed-pressure printed circuit board (HDI) comprising the following steps: cutting → inner layer → etching → inspection → browning → lamination → copper reduction → laser drilling → desmearing → copper deposition → hole filling → copper reduction → hole filling → copper reduction → drilling → desmearing → board printing → outer layer pattern transfer → etching → AOI inspection → solder mask printing → text printing → molding → flying probe testing → silver deposition → appearance inspection → packaging. This method solves the problem of incomplete hole filling in high-frequency, mixed-pressure HDI boards; it optimizes the hole filling and surface copper ratio parameters of high-frequency, mixed-pressure HDI boards, improves the quality issues of thick surface copper and poor uniformity in traditional processes, and reduces labor and material costs. In the actual production process, the technical defects of this existing technology are: the copper thickness on both sides of L1-L6 is different. When micro-etching to reduce copper, the surface copper of L6 is easily excessively corroded, and the copper plating uniformity of PTH is also lacking. The resin is easily exposed at the surface plug hole cover, thus failing to meet the standard product requirements. Summary of the Invention

[0003] In response to the above problems, the present invention provides a method for manufacturing a six-layer high-frequency hybrid circuit board, which improves the manufacturing steps, enhances the uniformity of copper reduction, avoids resin exposure at the surface plug hole cover, and improves the quality of the hybrid circuit board.

[0004] To achieve the above object, the present invention solves it through the following technical solutions:

[0005] A method for manufacturing a six-layer high-frequency mixed-pressure circuit board, comprising the following steps: inner layer → lamination → ceramic grinding → primary dry film → primary micro-etching and copper reduction → primary resin grinding → primary drilling → primary electroplating → resin plugging → secondary resin grinding → secondary micro-etching and copper reduction → tertiary resin grinding → secondary electroplating → outer layer dry film → outer layer etching → AOI → solder mask → secondary drilling → profiling → testing → AVI → nickel-palladium-gold → packaging;

[0006] The inner layer step includes L1-L2 inner layer, L3-L4 inner layer, and L5-L6 inner layer;

[0007] The substrate of the L1-L2 inner layer is set as a high-frequency hydrocarbon plate, and the L1-L2 inner layer steps include: material delivery → micro-etching and copper reduction A → drilling A → electroplating A → hole inspection → resin plugging A → resin grinding A → dry film A → etching A → one AOI; in the micro-etching and copper reduction A step, the copper reduction speed through browning is 5m / min, the number of times is set to 2, and the copper is reduced to 12.7um; in the resin grinding A step, the front and back sides need to be rotated in order during grinding to avoid a large difference in copper thickness on both sides; in the dry film A step, an inner layer coating operation is used, the pre-treatment speed is 3m / min, and the coating thickness is 11-13um. The coated plate needs to be wrapped in an opaque plastic bag or film bag and sent to the outer layer for exposure, and the exposure energy is 4-5 grids;

[0008] The substrate of the L3-L4 inner layer is set to FR4 board, the pre-treatment speed of the L3-L4 inner layer is 3m / min, the coating thickness is 11-13um, the exposure energy is 7-9 grids, and the etching speed is 7.5m / min;

[0009] The substrate of the L5-L6 inner layer is set to FR4 board, the pre-treatment speed of the L5-L6 inner layer is 3m / min, the coating thickness is 11-13um, the exposure energy is 7-9 grids, and the etching speed is 7.5m / min;

[0010] In the pressing step, hot melting is performed twice;

[0011] In the one-time dry film step, the L6 surface is fully covered with dry film and air-exposed without tearing off the protective film;

[0012] During the one-time drilling step, the board surface needs to be covered with an aluminum sheet;

[0013] In the secondary electroplating step, the resin cover is plated with copper of 0.5-0.8 mil, and the surface copper thickness is set to 28-40 um;

[0014] In the outer layer etching step, the inner layer etching line is passed at a speed of 5.06 m / min;

[0015] In the solder mask step, the pre-processing speed is 2.3 m / min; the exposure is performed using a double-sided CCD alignment exposure machine to prevent exposure offset, the exposure energy is 8-9 grids, and the development speed is 4.5 m / min;

[0016] The first micro-etching copper reduction step and the second micro-etching copper reduction step both use an etching machine to perform copper reduction operations.

[0017] Preferably, in the one-time micro-etching copper reduction step, the alkaline washing tank needs to be closed before browning, the browning copper reduction speed is set to 2m / min, and the number of times is set to 4 times; the copper is reduced to 15um.

[0018] Preferably, in the one electroplating step, the glue is removed twice and the hole copper thickness is 23um.

[0019] Preferably, in the secondary resin grinding step, the front and back sides need to be ground alternately in an orderly manner to avoid a large difference in copper thickness between the two sides.

[0020] Preferably, in the secondary micro-etching copper reduction step, the browning copper reduction speed is set to 2.5 m / min, and the number of times is set to 4 times; the copper is reduced to 16-20 um.

[0021] Preferably, during the secondary drilling step, the board surface needs to be covered with an aluminum sheet.

[0022] Preferably, in the drilling step A, the drilling coefficients are set to X=100.01%, Y=100.0%.

[0023] Preferably, the nickel-palladium-gold process requires baking at 150° for 30 minutes.

[0024] The beneficial effects of the present invention are as follows: in the first dry film step, the L6 surface is fully covered with dry film and air-exposed without tearing the protective film; the first micro-etching copper reduction step and the second micro-etching copper reduction step both use an etching machine to reduce copper, thereby improving the uniformity of copper reduction; in the second electroplating step, the resin cover is copper-plated with 0.5-0.8 mil, and the surface copper thickness is set to 28-40 um, thereby avoiding resin exposure at the surface plug hole cover, thereby improving the quality of the mixed pressure circuit board. DETAILED DESCRIPTION

[0025] The present invention will be further described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto.

[0026] A method for manufacturing a six-layer high-frequency mixed-pressure circuit board, comprising the following steps: inner layer → lamination → ceramic grinding → primary dry film → primary micro-etching and copper reduction → primary resin grinding → primary drilling → primary electroplating → resin plugging → secondary resin grinding → secondary micro-etching and copper reduction → tertiary resin grinding → secondary electroplating → outer layer dry film → outer layer etching → AOI → solder mask → secondary drilling → profiling → testing → AVI → nickel-palladium-gold → packaging;

[0027] The inner layer step includes L1-L2 inner layer, L3-L4 inner layer, and L5-L6 inner layer;

[0028] The substrate of the L1-L2 inner layer is set as a high-frequency hydrocarbon plate, and the L1-L2 inner layer steps include: material delivery → micro-etching and copper reduction A → drilling A → electroplating A → hole inspection → resin plugging A → resin grinding A → dry film A → etching A → one AOI; in the micro-etching and copper reduction A step, the copper reduction speed through browning is 5m / min, the number of times is set to 2, and the copper is reduced to 12.7um; in the resin grinding A step, the front and back sides need to be rotated in order during grinding to avoid a large difference in copper thickness on both sides; in the dry film A step, an inner layer coating operation is used, the pre-treatment speed is 3m / min, and the coating thickness is 11-13um. The coated plate needs to be wrapped in an opaque plastic bag or film bag and sent to the outer layer for exposure, and the exposure energy is 4-5 grids;

[0029] The substrate of the L3-L4 inner layer is set to FR4 board, the pre-treatment speed of the L3-L4 inner layer is 3m / min, the coating thickness is 11-13um, the exposure energy is 7-9 grids, and the etching speed is 7.5m / min;

[0030] The substrate of the L5-L6 inner layer is set to FR4 board, the pre-treatment speed of the L5-L6 inner layer is 3m / min, the coating thickness is 11-13um, the exposure energy is 7-9 grids, and the etching speed is 7.5m / min;

[0031] In the pressing step, hot melting is performed twice;

[0032] In the one-time dry film step, the L6 surface is fully covered with dry film and air-exposed without tearing off the protective film;

[0033] During the one-time drilling step, the board surface needs to be covered with an aluminum sheet;

[0034] In the secondary electroplating step, the resin cover is plated with copper of 0.5-0.8 mil, and the surface copper thickness is set to 28-40 um;

[0035] In the outer layer etching step, the inner layer etching line is passed at a speed of 5.06 m / min, with less side etching and better uniformity;

[0036] In the solder mask step, the pre-processing speed is 2.3 m / min; the exposure is performed using a double-sided CCD alignment exposure machine to prevent exposure offset, the exposure energy is 8-9 grids, and the development speed is 4.5 m / min;

[0037] The first micro-etching copper reduction step and the second micro-etching copper reduction step both use an etching machine to perform copper reduction operations.

[0038] Preferably, in the one-time micro-etching copper reduction step, the alkaline washing tank needs to be closed before browning, the browning copper reduction speed is set to 2m / min, and the number of times is set to 4 times; the copper is reduced to 15um.

[0039] Preferably, in the one electroplating step, the glue is removed twice and the hole copper thickness is 23um.

[0040] Preferably, in the secondary resin grinding step, the front and back sides need to be ground alternately in an orderly manner to avoid a large difference in copper thickness between the two sides.

[0041] Preferably, in the secondary micro-etching copper reduction step, the browning copper reduction speed is set to 2.5 m / min, and the number of times is set to 4 times; the copper is reduced to 16-20 um.

[0042] Preferably, during the secondary drilling step, the board surface needs to be covered with an aluminum sheet.

[0043] Preferably, in the drilling step A, the drilling coefficients are set to X=100.01%, Y=100.0%.

[0044] Preferably, the nickel-palladium-gold process requires baking at 150° for 30 minutes.

[0045] In this embodiment, in the first dry film step, the L6 surface is fully covered with dry film and exposed without tearing off the protective film. The first micro-etching and copper reduction step and the second micro-etching and copper reduction step both use an etching machine to reduce copper, thereby improving the uniformity of copper reduction. In the second electroplating step, the resin cover is plated with 0.5-0.8 mil copper, and the surface copper thickness is set to 28-40 um, so that the copper on the resin is thickened during subsequent copper plating. When the copper is reduced again, the resin is avoided from being exposed at the surface tree plug hole cover, thereby improving the quality of the mixed pressure circuit board.

[0046] The above embodiment merely represents one embodiment of the present invention, and while the description is relatively specific and detailed, it should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the scope of the present invention, and these modifications and improvements fall within the scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for manufacturing a six-layer high-frequency mixed-voltage circuit board, comprising the following steps: inner layer → lamination → ceramic grinding → primary dry film → primary micro-etching and copper reduction → primary resin grinding → primary drilling → primary electroplating → resin plugging → secondary resin grinding → secondary micro-etching and copper reduction → tertiary resin grinding → secondary electroplating → outer layer dry film → outer layer etching → AOI → solder mask → secondary drilling → profiling → testing → AVI → nickel-palladium-gold → packaging; characterized in that: The inner layer step includes L1-L2 inner layer, L3-L4 inner layer, and L5-L6 inner layer; The substrate of the L1-L2 inner layer is set as a high-frequency hydrocarbon plate, and the L1-L2 inner layer steps include: material delivery → micro-etching and copper reduction A → drilling A → electroplating A → hole inspection → resin plugging A → resin grinding A → dry film A → etching A → one AOI; in the micro-etching and copper reduction A step, the copper reduction speed through browning is 5m / min, the number of times is set to 2, and the copper is reduced to 12.7um; in the resin grinding A step, the front and back sides need to be rotated in order during grinding to avoid a large difference in copper thickness on both sides; in the dry film A step, an inner layer coating operation is used, the pre-treatment speed is 3m / min, and the coating thickness is 11-13um. The coated plate needs to be wrapped in an opaque plastic bag or film bag and sent to the outer layer for exposure, and the exposure energy is 4-5 grids; The substrate of the L3-L4 inner layer is set to FR4 board, the pre-treatment speed of the L3-L4 inner layer is 3m / min, the coating thickness is 11-13um, the exposure energy is 7-9 grids, and the etching speed is 7.5m / min; The substrate of the L5-L6 inner layer is set to FR4 board, the pre-treatment speed of the L5-L6 inner layer is 3m / min, the coating thickness is 11-13um, the exposure energy is 7-9 grids, and the etching speed is 7.5m / min; In the pressing step, hot melting is performed twice; In the one-time dry film step, the L6 surface is fully covered with dry film and air-exposed without tearing off the protective film; During the one-time drilling step, the board surface needs to be covered with an aluminum sheet; In the secondary electroplating step, the resin cover is plated with copper of 0.5-0.8 mil, and the surface copper thickness is set to 28-40 um; In the outer layer etching step, the inner layer etching line is passed at a speed of 5.06 m / min; In the solder mask step, the pre-processing speed is 2.3 m / min; the exposure is performed using a double-sided CCD alignment exposure machine to prevent exposure offset, the exposure energy is 8-9 grids, and the development speed is 4.5 m / min; The first micro-etching copper reduction step and the second micro-etching copper reduction step both use an etching machine to perform copper reduction operations.

2. The method for manufacturing a six-layer high-frequency mixed-voltage circuit board according to claim 1, characterized in that: In the one-time micro-etching copper reduction step, the alkaline washing tank needs to be closed before browning, the browning copper reduction speed is set to 2m / min, and the number of times is set to 4; the copper is reduced to 15um.

3. The method for manufacturing a six-layer high-frequency mixed-voltage circuit board according to claim 1, characterized in that: In the one electroplating step, the glue is removed twice and the hole copper thickness is 23um.

4. The method for manufacturing a six-layer high-frequency mixed-voltage circuit board according to claim 1, characterized in that: In the secondary resin grinding step, the front and back sides need to be ground alternately in an orderly manner to avoid a large difference in copper thickness between the two sides.

5. The method for manufacturing a six-layer high-frequency mixed-voltage circuit board according to claim 1, characterized in that: In the secondary micro-etching copper reduction step, the browning copper reduction speed is set to 2.5 m / min, and the number of times is set to 4; the copper is reduced to 16-20 μm.

6. The method for manufacturing a six-layer high-frequency mixed-voltage circuit board according to claim 1, characterized in that: During the secondary drilling step, the board surface needs to be covered with aluminum sheets.

7. The method for manufacturing a six-layer high-frequency mixed-voltage circuit board according to claim 1, characterized in that: In the drilling step A, the drilling coefficients are set to X=100.01% and Y=100.0%.

8. The method for manufacturing a six-layer high-frequency mixed-voltage circuit board according to claim 1, characterized in that: The nickel-palladium-gold process requires baking at 150° for 30 minutes.