Manufacturing method of four-layer Teflon high-frequency mixed-voltage circuit board

Abstract

The invention provides a manufacturing method of a four-layer Teflon high-frequency mixed-voltage circuit board. Comprising the following steps of material distribution, manufacturing of an L1-L2 inner layer of a PTFE plate, manufacturing of an L3-L4 inner layer of an FR4 plate, pressing, primary drilling, high-pressure flushing, primary electroplating, primary film drying, primary etching, browning, solder mask, developing ink printing, silver electroplating, ink removal, secondary film drying, secondary etching, shape fishing, V-CUT, testing, AVI and packaging. Before the step of manufacturing the L3-L4 inner layer of the FR4 board, the FR4 board is baked to release stress, and after manufacturing of an internal circuit of the FR4 board is completed, a plurality of open grooves are milled in a non-circuit coverage area to release stress, and a plurality of first positioning holes are formed; the expansion and shrinkage proportion of the FR4 plate is tested and recorded through equipment and used in the pressing step; the manufacturing steps are improved, the probability of layer deviation and board warping is reduced, and the quality of the mixed-voltage circuit board is improved.

Description

Technical Field

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

[0002] The Chinese patent application publication number is CN 109862703 A, and the application publication date is June 7, 2019. It discloses a positioning method for the production of a mixed-pressed board, which includes the following steps: S1: cutting; S2: internal drilling, designing a mother-and-child board positioning hole program, drilling a first positioning hole group in the daughter board, drilling a second positioning hole group in the mother board, and drilling a third positioning hole group in the PP board through the mother-and-child board positioning hole program; S3: internal engraving, producing the inner layer graphics of each of the daughter boards and the mother board and etching the inner layer; S4: pressing, fixing the mother board, each of the daughter boards, and each of the PP boards with pins and putting them into a pressing machine for pressing; S5: removing the pins. Compared with the related art, the present invention controls the positioning accuracy of the mother-sub ... Summary of the invention

[0003] In view of the above problems, the present invention provides a method for manufacturing a four-layer Teflon high-frequency mixed-pressure circuit board, which improves the manufacturing steps, reduces the probability of layer deviation and board warping, and improves the quality of the mixed-pressure circuit board.

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

[0005] A method for manufacturing a four-layer Teflon high-frequency mixed-pressure circuit board, comprising the following steps: material delivery → manufacturing L1-L2 inner layers of PTFE sheets → manufacturing L3-L4 inner layers of FR4 sheets → pressing → drilling once → high-pressure washing → electroplating once → drying film once → etching once → browning → solder mask → visible ink printing → silver electroplating → ink removal → secondary drying film → secondary etching → scooping → V-CUT → testing → AVI → packaging;

[0006] Before the L3-L4 inner layer step of the FR4 board is made, the FR4 board is first baked to release stress. After the internal circuit of the FR4 board is made, a number of slots are milled in the non-circuit coverage area to release stress, and a plurality of first positioning holes are opened; the expansion and contraction ratio of the FR4 board is recorded by equipment testing for use in the pressing step;

[0007] After the L1-L2 inner layer step of the PTFE sheet, a plurality of second positioning holes corresponding to the positions of the first positioning holes are opened; the expansion and contraction ratio of the PTFE sheet is recorded by equipment testing for use in the pressing step;

[0008] Before the lamination step, the FR4 sheet and the PTFE sheet are positioned by positioning pins, and the lamination operation is performed according to the expansion and contraction ratio of the FR4 sheet and the PTFE sheet that has been tested and recorded; hot melting is performed twice; after the lamination is completed, the positioning pins are removed;

[0009] The one-time drilling step uses a colorful coated drill needle to drill holes; the stacked plate structure during drilling is aluminum sheet, FR4 plate, PTFE plate, bare base plate, and pad plate from top to bottom;

[0010] In the solder mask step, the electrostatic spraying operation needs to be completed within 6 hours after the etching is completed;

[0011] In the secondary dry film step, a wet film is first used as a primer, a thin layer of ink is applied to the inner layer, and then the dry film is pressed and then exposed and developed.

[0012] Preferably, after the drilling step, the plate needs to be subjected to a plasma debonding operation, and the plate after plasma debonding needs to complete an electroplating step within 5 hours.

[0013] Preferably, in the high-pressure flushing step, high-pressure cleaning is performed using a water pressure of 60KG / cm2 without brushing, and the conveying speed is 2.5m / min.

[0014] Preferably, before the browning step, two pieces of plain copper plates are placed in to confirm the scratches on the plate surface, and the browning step is started only after it is confirmed that there are no scratches.

[0015] Preferably, in the primary film drying step and the secondary film drying step, micro-etching is used as pre-treatment, and the conveying speed is 2.0 m / min; after the pre-treatment, the film is pressed within 2 hours, and the pressing speed is 2.5 m / min.

[0016] Preferably, in the ink printing step, the pre-baking condition is set to 80°C / 30min, and the post-baking condition is set to 150°C / 20min.

[0017] Preferably, in the de-inking step, alkaline etching is used for de-inking, and the de-inking speed is set to 4.0 m / min.

[0018] The beneficial effects of the present invention are: the stress of the FR4 sheet is released in advance by baking and grooving, and then the expansion and contraction ratio test of the FR4 sheet and the PTFE sheet is recorded by the equipment for use in the pressing step, thereby effectively reducing the probability of board warping, and then pressing is performed by cooperating with the locating pin and the first locating hole and the second locating hole, thereby effectively reducing the layer deviation problem occurring during the pressing process, thereby improving the quality of the mixed-pressed circuit board. DETAILED DESCRIPTION

[0019] The present invention is further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0020] A method for manufacturing a four-layer Teflon high-frequency mixed-pressure circuit board, comprising the following steps: material delivery → manufacturing L1-L2 inner layers of PTFE sheets → manufacturing L3-L4 inner layers of FR4 sheets → pressing → drilling once → high-pressure washing → electroplating once → drying film once → etching once → browning → solder mask → visible ink printing → silver electroplating → ink removal → secondary drying film → secondary etching → scooping → V-CUT → testing → AVI → packaging;

[0021] Before the L3-L4 inner layer step of the FR4 board is made, the FR4 board is first baked to release stress. After the internal circuit of the FR4 board is made, a number of slots are milled in the non-circuit coverage area to release stress, and a plurality of first positioning holes are opened; the expansion and contraction ratio of the FR4 board is recorded by equipment testing for use in the pressing step;

[0022] After the L1-L2 inner layer step of the PTFE sheet, a plurality of second positioning holes corresponding to the positions of the first positioning holes are opened; the expansion and contraction ratio of the PTFE sheet is recorded by equipment testing for use in the pressing step;

[0023] Before the lamination step, the FR4 sheet and the PTFE sheet are positioned by positioning pins, and the lamination operation is performed according to the expansion and contraction ratio of the FR4 sheet and the PTFE sheet that has been tested and recorded; hot melting is performed twice; after the lamination is completed, the positioning pins are removed;

[0024] The one-time drilling step uses a colorful coated drill needle for drilling; the stacked plate structure during drilling is aluminum sheet, FR4 plate, PTFE plate, bare base plate, and pad from top to bottom; after the one-time drilling step, the plate needs to be plasma debonded, and the plate after plasma debonding needs to complete an electroplating step within 5 hours.

[0025] In the high-pressure flushing step, high-pressure cleaning is performed using a water pressure of 60KG / cm2 without using a brush, and the conveying speed is 2.5m / min.

[0026] In the solder mask step, the electrostatic spraying operation needs to be completed within 6 hours after the etching is completed;

[0027] Before the browning step, put two pieces of copper plates in to check the scratches on the plate surface. The browning step will not start until there are no scratches.

[0028] In the secondary dry film step, a wet film is first used as a primer, a thin layer of ink is applied to the inner layer, and then the dry film is pressed and then exposed and developed.

[0029] In the first drying step and the second drying step, micro-etching is used as pre-treatment, and the conveying speed is 2.0 m / min; after the pre-treatment, the film is pressed within 2 hours, and the pressing speed is 2.5 m / min.

[0030] In the ink printing step, the pre-bake condition was set to 80°C / 30min, and the post-bake condition was set to 150°C / 20min.

[0031] In the de-inking step, alkaline etching is used for de-inking, and the de-inking speed is set to 4.0 m / min.

[0032] In this embodiment, the stress of the FR4 sheet is released in advance by baking and grooving, and then the expansion and contraction ratio test of the FR4 sheet and the PTFE sheet is recorded by the equipment for use in the pressing step, thereby effectively reducing the probability of board warping. Then, pressing is performed by cooperating with the locating pins and the first locating holes and the second locating holes, thereby effectively reducing the layer deviation problem that occurs during the pressing process, thereby improving the quality of the mixed-pressure circuit board.

[0033] The above embodiment only expresses one implementation mode of the present invention, and its description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A method for manufacturing a four-layer Teflon high-frequency mixed-pressure circuit board, comprising the following steps: Material delivery → production of L1-L2 inner layer of PTFE sheet → production of L3-L4 inner layer of FR4 sheet → pressing → primary drilling → high pressure washing → primary electroplating → primary dry film → primary etching → browning → solder mask → visible ink printing → electroplating silver → ink removal → secondary dry film → secondary etching → scooping → V-CUT → testing → AVI → packaging; it is characterized by: Before the L3-L4 inner layer step of the FR4 board is made, the FR4 board is first baked to release stress. After the internal circuit of the FR4 board is made, a number of slots are milled in the non-circuit coverage area to release stress, and a plurality of first positioning holes are opened; the expansion and contraction ratio of the FR4 board is recorded by equipment testing for use in the pressing step; After the L1-L2 inner layer step of the PTFE sheet, a plurality of second positioning holes corresponding to the positions of the first positioning holes are opened; the expansion and contraction ratio of the PTFE sheet is recorded by equipment testing for use in the pressing step; Before the lamination step, the FR4 sheet and the PTFE sheet are positioned by positioning pins, and the lamination operation is performed according to the expansion and contraction ratio of the FR4 sheet and the PTFE sheet that has been tested and recorded; hot melting is performed twice; after the lamination is completed, the positioning pins are removed; The one-time drilling step uses a colorful coated drill needle to drill holes; the stacked plate structure during drilling is aluminum sheet, FR4 plate, PTFE plate, bare base plate, and pad plate from top to bottom; In the solder mask step, the electrostatic spraying operation needs to be completed within 6 hours after the etching is completed; In the secondary dry film step, a wet film is first used as a primer, a thin layer of ink is applied to the inner layer, and then the dry film is pressed and then exposed and developed.

2. The method for manufacturing a four-layer Teflon high-frequency mixed-pressure circuit board according to claim 1, characterized in that: After the drilling step, the plate needs to be debonded by plasma, and the plate after plasma debonding needs to complete an electroplating step within 5 hours.

3. The method for manufacturing a four-layer Teflon high-frequency mixed-pressure circuit board according to claim 1, characterized in that: In the high-pressure flushing step, high-pressure cleaning is performed using a water pressure of 60KG / cm2 without brushing, and the conveying speed is 2.5m / min.

4. The method for manufacturing a four-layer Teflon high-frequency mixed-pressure circuit board according to claim 1, characterized in that: Before the browning step, two pieces of copper plates are placed in order to check the scratches on the plate surface. The browning step is started only after it is confirmed that there are no scratches.

5. The method for manufacturing a four-layer Teflon high-frequency mixed-pressure circuit board according to claim 1, characterized in that: In the first drying step and the second drying step, micro-etching is used as pre-treatment, and the conveying speed is 2.0 m / min; after the pre-treatment, the film is pressed within 2 hours, and the pressing speed is 2.5 m / min.

6. The method for manufacturing a four-layer Teflon high-frequency mixed-pressure circuit board according to claim 1, characterized in that: In the ink printing step, the pre-baking condition is set to 80° C. / 30 min, and the post-baking condition is set to 150° C. / 20 min.

7. The method for manufacturing a four-layer Teflon high-frequency mixed-pressure circuit board according to claim 1, characterized in that: In the de-inking step, alkaline etching is used for de-inking, and the de-inking speed is set to 4.0 m / min.