Method for manufacturing a thick copper winding coil circuit board

Abstract

The application provides a thick copper winding coil circuit board manufacturing method, which comprises the following steps: first, a through-hole metalization manufacturing is performed on an inner core plate; after inner photo-etching is performed on the inner core plate, high-temperature pressing is performed through a pressing formula; after pressing, controlled depth drilling is performed according to the conduction requirement; then, metalization manufacturing is performed to realize controlled depth hole conduction; after inner photo-etching is performed, high-temperature pressing is performed through a pressing formula to fill the controlled depth hole and increase the number of electroplated plate layers. The application is not limited by the number of electroplated plate layers and the thickness of copper, and can improve quality defects such as expansion and shrinkage deviation, and can realize mass production.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of circuit board manufacturing, in particular to a thick copper winding coil circuit board manufacturing method. BACKGROUND

[0002] The existing winding coil circuit board has the product design feature of thick copper design (70-350um), and at present, 99% of the designs are hard board multi-layer designs, and 1% of the proportion is made by HDI (arbitrary interconnection) Comformal (isometric) windowing process (low-end 4-6 layer products).

[0003] The industry capability of the HDI (arbitrary interconnection) process is that the laser breakdown surface copper thickness is 12um at most, the ratio of the dielectric layer thickness to the laser hole depth is 1:1, and the laser hole is 150um at most. However, the coil board needs to pass the high pressure requirement, and the copper thickness design is 70-350um, and the dielectric thickness is about 200um, so the selection of the Comformal (isometric) windowing product market application face is relatively narrow. At the same time, the selection of the Comformal (isometric) windowing process also faces the influence of product quality by many factors such as the alignment capability of the outer pattern alignment accuracy (limit ±20um) + drilling precision (±38um) + multiple pressing alignment accuracy (±75um), so the thick copper coil 99% design can only be the conventional multi-layer board design. SUMMARY

[0004] The present application provides a thick copper winding coil circuit board manufacturing method to solve at least one of the above technical problems.

[0005] In order to solve the above problems, as one aspect of the present application, a thick copper winding coil circuit board manufacturing method is provided, comprising:

[0006] Step 1, cutting:

[0007] Cut the intermediate core (L5-6) layer copper clad plate into the designed size by a cutting machine;

[0008] Step 2, drilling:

[0009] Use a high-speed drilling machine to process through holes according to the 2-layer circuit board process;

[0010] Step 3, hole metallization 1, comprising:

[0011] Copper plating: the hole metallization treatment is performed on the drilled plate to form a conductive layer in the L5-6 layer intermediate substrate area;

[0012] VCP electroplating: the copper plating layer is thickened by electroplating after copper plating;

[0013] Step 4, inner layer imaging 1:

[0014] After the dry film is pasted on the board surface, the film is aligned with the negative, and finally, the unshielded dry film of the negative is reacted by ultraviolet light irradiation on the exposure machine to form the required circuit pattern on the board surface. Then, the film that is not irradiated by light is dissolved by the developing solution in the developing section, and the area to be etched is exposed;

[0015] Step 5, inner layer etching 1:

[0016] The exposed copper is etched by the acid etching solution in the etching section, and the film is removed by the stripping solution in the stripping section to expose the inner layer circuit pattern;

[0017] Step 6, laminating 1:

[0018] L5-6 layers are browned before lamination, L5 and L6 layers each add two RC64% PP of 1080 model and one RC64% PP of 106 model, and are fixed by high-temperature fusion. The resin of the prepreg flows and fills the through-hole, circuit and substrate of L5-6 layers. When the temperature reaches a certain degree, curing occurs to bond the layers together, finally forming L4-7 layers (4-layer board);

[0019] Step 7, controlled depth drilling 1:

[0020] High-speed drilling machines are used to drill controlled depth connection holes in L4-5 layers and L6-7 layers, respectively;

[0021] Step 8, repeat steps 3-7, form L3-8 layers (6-layer board) outside L4 and L7 layers, respectively;

[0022] Step 9, repeat steps 3-7, form L2-9 layers (8-layer board) outside L3 and L8 layers, respectively;

[0023] Step 10, repeat steps 3-7, form L1-10 layers (10-layer board) outside L2 and L9 layers, respectively;

[0024] Step 11, resin hole filling:

[0025] The controlled depth through-hole of L1 layer and L10 layer is filled with resin by a vacuum resin hole filling machine, and after high-temperature curing, the surface protruding resin is removed;

[0026] Step 12, outer layer imaging:

[0027] After the dry film is pasted on the board surface at a certain temperature and pressure, the film is aligned with the negative, and finally, the unshielded dry film of the negative is reacted by ultraviolet light irradiation on the exposure machine to form the required circuit pattern on the board surface. Then, the film that is not irradiated by light is dissolved by the developing solution in the developing section, and the area to be etched is exposed;

[0028] Step 13, outer layer acid etching:

[0029] Through the etching section, the exposed copper is etched away under the action of the acid etching solution, and finally through the film stripping section, the film is removed under the action of the film stripping solution, and the outer circuit pattern is exposed.

[0030] The present application is not limited by the number of plated layers and the thickness of copper, and can be theoretically produced without limitation under the condition that the production equipment can produce the correct plate thickness, copper thickness and pressing formula (normal plate factory capacity can reach 6.0mm plate thickness, copper thickness 35-350um), which can completely replace the HDI (arbitrary interconnection) Comformal (isometric) windowing process, while improving the quality problems such as expansion and shrinkage, and realizing mass production. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The processing process schematic diagram of steps 1-5 (L5-6 layers) is schematically shown;

[0032] Figure 2 The processing process schematic diagram of steps 6-10 (L4-7 layers) is schematically shown;

[0033] Figure 3 The processing process schematic diagram of steps 11-15 (L3-8 layers) is schematically shown;

[0034] Figure 4 The processing process schematic diagram of steps 16-20 (L2-9 layers) is schematically shown;

[0035] Figure 5 The processing process schematic diagram of steps 21-29 (L1-10 layers) is schematically shown;

[0036] Figure 6 The actual product partial structure diagram is schematically shown. DETAILED DESCRIPTION

[0037] The embodiments of the present application are described in detail below, but the present application can be implemented in various different ways limited and covered by the claims.

[0038] The present application provides a thick copper coil circuit board manufacturing process method, which can completely solve the problem of replacing the HDI (arbitrary interconnection) Comformal (isometric) windowing process, and at the same time solve the technical problem of conventional hard plate factory unable to produce HDI (arbitrary interconnection) thick copper product, to replace the technical barrier of thick copper plate production in the current circuit board industry using HDI (arbitrary interconnection) Comformal (isometric) windowing process.

[0039] The main production process of the present application is: cutting → drilling → copper deposition / VCP electroplating 1 → inner light imaging 1 → inner layer etching 1 → pressing 1 → depth control drilling 1 → copper deposition / VCP electroplating 2 → inner light imaging 2 → inner layer etching 2 → pressing 2 → depth control drilling 2 → copper deposition / VCP electroplating 3 → inner light imaging 3 → inner layer etching 3 → pressing 3 → depth control drilling 3 → copper deposition / VCP electroplating 4 → inner light imaging 4 → inner layer etching 4 → pressing 4 → depth control drilling 4 → copper deposition / VCP electroplating 5 → resin hole plugging → outer light imaging → circuit etching → AOI detection → solder mask imaging → …… subsequent process

[0040] In the present application, a through-hole metallization of an inner core board is first made, after inner core board inner light etching, high temperature pressing is performed through pressing formula (PP + copper foil), then depth control drilling is performed according to the on-off requirement, then metallization is made for depth control hole on-off, and after inner light etching, high temperature pressing is performed through pressing formula (PP + copper foil) to fill the depth control hole and increase the number of electroplated layers.

[0041] The present application is not limited by the number of electroplated layers and the thickness of copper, and under the condition that the production equipment can produce the correct plate thickness, copper thickness and pressing formula, it can be theoretically produced without limitation (according to the current plate factory capacity, it can normally reach 6.0mm plate thickness, copper thickness 35-350um), which can completely replace the HDI (arbitrary interconnection) conformal (isometric) windowing process, and can improve the quality problems such as expansion and shrinkage, and can realize mass production.

[0042] In one embodiment, the specific implementation steps and methods of the present application are as follows:

[0043] Step 1: Cutting:

[0044] The intermediate core (L5-6) layer copper clad plate is cut into the designed size by a cutting machine.

[0045] Step 2: Drilling:

[0046] The through hole is processed according to the 2-layer circuit board process using a high-speed drilling machine.

[0047] Step 3: Hole metallization 1 (copper deposition, VCP electroplating):

[0048] Copper deposition: The hole metallization treatment is performed on the drilled plate, and the main purpose of the treatment is to form a conductive layer in the L5-6 layer of the substrate area, and the copper layer generated is about 0.4um;

[0049] VCP electroplating: The copper deposition layer is thickened by electroplating after copper deposition, and the thickness is about 25-40um, and the thickness of L5-6 layer surface is thickened by about 35-50um (the thickness can be adjusted according to the actual product requirements).

[0050] Step 4 inner layer imaging 1:

[0051] Under certain temperature and pressure, dry film is pasted on the plate surface, then the negative is aligned, and finally the unshielded dry film of the negative is reacted by ultraviolet light irradiation on the exposure machine. The required circuit pattern is formed on the plate surface, and then through the development section, the film that has not been irradiated is dissolved by the action of the developing solution, and the area that needs to be etched is exposed.

[0052] Step 5 inner layer etching 1:

[0053] Through the etching section, the exposed copper is etched away by the action of the acid etching solution, and finally through the film stripping section, the film is removed by the action of the film stripping solution, exposing the inner layer circuit pattern.

[0054] Step 6 lamination 1:

[0055] L5-6 layers are browned before lamination, L5 and L6 layers each add two RC64% PP of model 1080 and one RC64% PP of model 106, and are fixed by high temperature fusion. Under the action of certain temperature and pressure, the resin of the prepreg flows to fill the through-hole, circuit and substrate of L5-6 layers. When the temperature reaches a certain degree, curing occurs, bonding the layers together, and finally forming L4-7 layers (thus obtaining a 4-layer board)

[0056] Step 7 controlled depth drilling 1:

[0057] Use a high-speed drill to drill controlled depth connection holes in L4-5 layers and L6-7 layers respectively.

[0058] Step 8 hole metallization 2 (copper deposition, VCP plating):

[0059] Copper deposition: The hole metallization treatment is performed on the plate after drilling. The main purpose of the treatment is to form a conductive layer in the substrate area between L4-5 layers and L6-7 layers. The copper layer produced is about 0.4um thick;

[0060] VCP plating: The copper deposition layer is thickened by electroplating after copper deposition. The thickness is about 25-40um, and the surface thickness of L4-7 layers is thickened by about 35-50um (the actual product thickness can be adjusted according to actual product requirements).

[0061] Step 9 inner layer imaging 2:

[0062] Under certain temperature and pressure, dry film is pasted on the plate surface, then the negative is aligned, and finally the unshielded dry film of the negative is reacted by ultraviolet light irradiation on the exposure machine. The required circuit pattern is formed on the plate surface, and then through the development section, the film that has not been irradiated is dissolved by the action of the developing solution, and the area that needs to be etched is exposed.

[0063] Step 10 inner layer etching 2:

[0064] Through the etching section, the exposed copper is etched away under the action of an acidic etching solution, and finally through the film stripping section, the film is removed under the action of a film stripping solution, exposing the inner layer circuit pattern.

[0065] Step 11 laminating 2:

[0066] L4-7 layers are browned before lamination, L4 and L7 layers each increase two 1080 model RC64%PP and one 106 model RC64%PP, which are fixed by high temperature melting. After entering the high temperature press, under the action of certain temperature and pressure, the resin of the prepreg flows to fill the L4-5 layers and the L6-7 layer controlled depth through hole, circuit and substrate. When the temperature reaches a certain degree, curing occurs, bonding the layers together, and finally forming L3-8 layers (thus obtaining a 6-layer board)

[0067] Step 12 controlled depth drilling 2:

[0068] Use a high-speed drilling machine to drill controlled depth connection holes in L3-4 layers and L7-8 layers, respectively.

[0069] Step 13 hole metallization 3 (copper deposition, VCP electroplating):

[0070] Copper deposition: The hole metallization treatment is performed on the drilled board, and the main purpose of the treatment is to form a conductive layer in the substrate area between L3-4 layers and L7-8 layers. The copper layer produced is about 0.4um thick;

[0071] VCP electroplating: The copper deposition layer is thickened by electroplating after copper deposition, with a thickness of about 25-40um, and the surface thickness of L3-8 layers is thickened by about 35-50um (the actual product thickness can be adjusted according to the actual product requirements).

[0072] Step 14 inner layer imaging 3:

[0073] Under certain temperature and pressure, dry film is attached to the board surface, then aligned with the negative, and finally exposed to ultraviolet light in the exposure machine to react with the unshielded dry film. The negative forms the required circuit pattern on the board surface, and then through the developing section, the film that has not been irradiated is dissolved in the developing solution, exposing the area to be etched.

[0074] Step 15 inner layer etching 3:

[0075] Through the etching section, the exposed copper is etched away under the action of an acidic etching solution, and finally through the film stripping section, the film is removed under the action of a film stripping solution, exposing the inner layer circuit pattern.

[0076] Step 16 laminating 3:

[0077] L3-8 layers are browned by lamination, L3 and L8 layers each increase two 1080 model RC64% PP and one 106 model RC64% PP, fixed by high temperature fusion, after entering the high temperature press, under the action of certain temperature and pressure, the resin of the prepreg flows, fills the L3-4 layers and L7-8 layers of the controlled depth through-hole, circuit and substrate, when the temperature reaches a certain degree, curing occurs, bonding the layers together, finally forming L2-9 layers (thus obtaining an 8-layer board)

[0078] Step 17 controlled depth drilling 3:

[0079] Use a high-speed drilling machine to drill controlled depth connection holes in L2-3 layers and L8-9 layers respectively.

[0080] Step 18 hole metallization 4 (copper deposition, VCP plating):

[0081] Copper deposition: The hole metallization treatment is performed on the drilled plate, the main purpose of the treatment is to form a conductive layer in the substrate area between L2-3 layers and L8-9 layers, and the copper layer produced is about 0.4um;

[0082] VCP plating: The copper deposition layer is thickened by electroplating after copper deposition, the thickness is about 25-40um, and the surface thickness of L2-9 layers is thickened by about 35-50um (the thickness can be adjusted according to actual product requirements).

[0083] Step 19 inner layer imaging 4:

[0084] Under certain temperature and pressure, dry film is attached to the plate surface, then the negative is aligned, and finally the unshielded dry film of the negative is reacted by ultraviolet light irradiation in the exposure machine. Form the required circuit pattern on the plate surface, then through the development section, the film that has not been irradiated is dissolved in the developer, and the area to be etched is exposed.

[0085] Step 20 inner layer etching 4:

[0086] Through the etching section, the exposed copper is etched away under the action of the acid etching solution, and finally through the film stripping section, the film is removed by the stripping solution, exposing the inner layer circuit pattern.

[0087] Step 21 lamination 4:

[0088] L2-9 layers are fixed by lamination and pre-browning, L2 and L9 layers are each added with two 1080 type RC64%PP and one 106 type RC64%PP, and fixed by high temperature melting. After entering the high temperature press, the resin of the prepreg flows and fills the L2-3 layers and L8-9 layers of the controlled depth through-hole, circuit and substrate under the action of certain temperature and pressure. When the temperature reaches a certain degree, curing occurs, and the layers are bonded together, finally forming L1-10 layers (thus obtaining a 10-layer board)

[0089] Step 22 controlled depth drilling 4:

[0090] Use a high-speed drilling machine to drill controlled depth connection holes in L1-2 layers and L9-10 layers, respectively.

[0091] Step 23 hole metallization 5 (copper plating, VCP plating):

[0092] Copper plating: The hole metallization treatment is performed on the drilled board, and the main purpose of the treatment is to form a conductive layer in the substrate area between L1-2 layers and L9-10 layers. The copper layer produced is about 0.4um thick;

[0093] VCP plating: The copper plating layer is thickened by electroplating after copper plating, with a thickness of about 25-40um, and the surface thickness of L1-10 layers is thickened by about 35-50um (the actual product thickness can be adjusted according to the actual product requirements).

[0094] Step 24 resin plug hole:

[0095] The controlled depth through-hole of L1 layer and L10 layer is filled with resin by a vacuum resin plug hole machine. After high temperature curing, the surface protruding resin is removed using a ceramic grinding plate machine.

[0096] Step 25 outer layer imaging:

[0097] Under certain temperature and pressure, dry film is attached to the board surface, then aligned with the negative, and finally exposed to ultraviolet light in the exposure machine to react with the dry film that is not shielded by the negative. The required circuit pattern is formed on the board surface, and then through the development section, the film that is not exposed to light is dissolved in the developer, and the area to be etched is exposed.

[0098] Step 26 outer layer acid etching:

[0099] Through the etching section, the exposed copper is etched away by the action of the acid etching solution, and finally through the film stripping section, the film is removed by the action of the film stripping solution, exposing the outer layer circuit pattern.

[0100] Step 27 outer layer AOI:

[0101] Open short circuit detection and repair

[0102] Step 28 solder mask printing:

[0103] The whole board is printed with a layer of insulating anti-corrosion green paint by twice printing, and after printing, the surface is baked and solidified after standing for more than 30 minutes.

[0104] Step 29 solder mask imaging:

[0105] The unshielded part of the negative is reacted with light by using ultraviolet light irradiation on the exposure machine. Then, through the development section, the unreacted green paint is dissolved and stripped under the action of the developing solution, forming a bare copper circuit, and then the green paint is cured at high temperature.

[0106] After the application of the present application, the HDI (arbitrary interconnection) Comformal (isometric) windowing process can be completely replaced, and the problem of the conventional hard board factory being unable to manufacture HDI (arbitrary interconnection) Comformal (isometric) windowing winding motor coil board due to limited equipment process is solved.

[0107] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for manufacturing a thick copper wire-wound coil circuit board, characterized in that, include: Step 1, Cutting materials: The copper-clad laminate of the middle core (L5-6) layer is cut to the design size using a cutting machine; Step 2, Drilling: Use a high-speed drilling machine to process through holes according to the two-layer circuit board process; Step 3, Hole Metallization 1, includes: Plating copper: Metallizing the holes in the board after drilling, so that a conductive layer is formed in the substrate area between layers L5 and L6. VCP plating: The copper layer is thickened by electroplating on the board after copper plating. Step 4, Inner Layer Imaging 1: A dry film is applied to the board surface, then the film is aligned, and finally, ultraviolet light is used in the exposure machine to cause the dry film not covered by the film to react and form the required circuit pattern on the board surface. Then, in the developing section, the film that has not been exposed to light is dissolved by the developing solution, exposing the area that needs to be etched. Step 5, Inner layer etching 1: The exposed copper is etched away in the etching section under the action of acidic etching solution, and the film is removed in the stripping section under the action of stripping solution, exposing the inner layer circuit pattern. Step 6, Lamination 1: Layers L5-6 undergo pre-lamination browning. Two 1080 type RC64% PP sheets and one 106 type RC64% PP sheet are added to the outside of layers L5 and L6. They are fixed by high-temperature fusion. The resin of the prepreg is then fed into a high-temperature press to flow and fill the through holes, circuits and substrate of layers L5-6. When the temperature reaches a certain level, curing occurs, bonding the layers together to finally form layers L4-7 (4-layer board). Step 7, controlled depth drilling 1: Use a high-speed drilling rig to drill depth-controlled connection holes for layers L4-5 and L6-7 respectively; Step 8: Repeat steps 3-7 to form layers L3-8 (6-layer board) outside layers L4 and L7; Step 9: Repeat steps 3-7 to form layers L2-9 (8-layer board) outside layers L3 and L8; Step 10: Repeat steps 3-7 to form layers L1-10 (10-layer board) outside layers L2 and L9; Step 11, Resin plugging: The controlled depth through holes of L1 and L10 layers are filled with resin using a vacuum resin plugging machine. After high-temperature curing, the surface protruding resin is removed. Step 12, outer layer imaging: Under certain temperature and pressure conditions, a dry film is applied to the board surface, then the film is aligned, and finally, ultraviolet light is used in the exposure machine to cause the dry film not covered by the film to react, forming the required circuit pattern on the board surface. Then, in the developing section, the film that has not been exposed to light is dissolved by the developing solution, exposing the area that needs to be etched. Step 13, outer layer acid etching: In the etching section, the exposed copper is etched away under the action of acidic etching solution. Finally, in the stripping section, the film is removed under the action of stripping solution, exposing the outer circuit pattern.

Images