阅读说明：本技术 线路板金属盲槽的制作方法 (Method for manufacturing metal blind slot of circuit board ) 是由 许龙龙 陈黎阳 于 2019-10-17 设计创作，主要内容包括：本发明公开了一种线路板金属盲槽的制作方法，在线路板上设置待开槽区域，并对所述待开槽区域进行开槽，使得线路板上形成盲槽；开槽后，在盲槽的底部上进行开孔，使得盲槽底部形成第一附着孔，如此，当线路板进行沉铜时，第一附着孔内会附着金属铜；金属铜附着后，线路板再进行板面电镀，此时，盲槽底部形成的镀层会与第一附着孔内的金属铜连接，这样，通过第一附着孔内的金属铜，提高镀层与盲槽内的基材之间的着附力，使得镀层与盲槽紧密结合，减少镀层从基材上剥离的发生率，保证产品能够正常交货。由于第一附着孔沿着盲槽的周向延伸设置，因此，本实施例的第一附着孔呈环形结构，进一步提高了镀层与盲槽内的基材之间的着附力。(The invention discloses a method for manufacturing a metal blind slot of a circuit board.A region to be slotted is arranged on the circuit board, and the region to be slotted is slotted, so that the blind slot is formed on the circuit board; after slotting, perforating the bottom of the blind slot to form a first attachment hole at the bottom of the blind slot, so that metal copper can be attached to the first attachment hole when the circuit board is subjected to copper deposition; after the metal copper adheres to, the face is electroplated again to the circuit board, and at this moment, the cladding material that blind groove bottom formed can be connected with the metal copper in the first attachment hole, like this, through the metal copper in the first attachment hole, improve the adhesion between the base material in cladding material and the blind groove for cladding material and blind groove closely combine, reduce the incidence that the cladding material peeled off from the base material, guarantee that the product can normally be delivered goods. Because the first attaching hole extends along the circumferential direction of the blind groove, the first attaching hole of the embodiment is of an annular structure, and the attaching force between the plating layer and the base material in the blind groove is further improved.)

1. A method for manufacturing a metal blind slot of a circuit board is characterized by comprising the following steps:

arranging a region to be grooved on the circuit board;

after the arrangement, slotting is carried out in the area to be slotted, so that a blind slot is formed on the circuit board;

after grooving, forming a hole in the bottom of the blind groove, so that a first attachment hole is formed in the bottom of the blind groove, wherein the first attachment hole extends along the circumferential direction of the blind groove.

2. The method for manufacturing the metal blind groove of the circuit board according to claim 1, wherein the width W of the first attachment hole is 0.4mm to 0.8 mm; the depth h of the first attachment hole is 0.1 mm-0.5 mm.

3. The method for manufacturing the metal blind groove of the circuit board according to claim 1, wherein after the step of arranging, grooving in the region to be grooved so as to form the blind groove on the circuit board comprises the following steps:

dividing the area to be grooved into a main groove area and an auxiliary groove area surrounding the edge of the main groove area;

grooving in the main groove area to form a first groove in the main groove area;

and grooving in the auxiliary groove area, so that a second groove is formed in the auxiliary groove area, wherein the first groove and the second groove form the blind groove.

4. The method for manufacturing the blind metal slot of the circuit board according to claim 3, wherein the step of slotting in the main slot region so as to form the first groove in the main slot region includes:

acquiring a first processing position in the main groove area;

starting the milling cutter, and drilling on the first machining position to enable the hole depth to be a first preset depth value;

after drilling, moving the milling cutter in a direction away from the first machining position by a first preset distance value, and controlling the first preset distance value to be smaller than or equal to the diameter of the milling cutter;

after moving a first preset distance value, moving the milling cutter around the first machining position, milling the main groove area, and enabling the machining track of the milling cutter to be annular;

and after the annular movement, repeatedly moving the milling cutter by the first preset distance value and moving around the first machining position until the base material in the main groove area is milled away.

5. The method for manufacturing the blind metal slot according to claim 3, wherein the step of slotting in the sub-slot region so as to form the second groove in the sub-slot region includes:

selecting more than two second processing stations at intervals in the auxiliary groove area;

starting the milling cutter, and drilling on the second machining position to enable the hole depth to be a second preset depth value;

after drilling, moving the milling cutter in the direction away from the second machining position by a second preset distance value, and controlling the second preset distance value to be smaller than or equal to the diameter of the milling cutter;

after moving a second preset distance value, moving the milling cutter around the second machining position, milling the auxiliary groove area, and enabling the machining track of the milling cutter to be annular;

and after the annular movement, repeatedly moving the milling cutter by the second preset distance value and moving around the second machining position until the base material in the auxiliary groove area is milled away.

6. The method for manufacturing the blind metal slot of the circuit board according to claim 3, wherein after the slot is opened, a hole is formed on the bottom of the blind slot, so that a first attachment hole is formed on the bottom of the blind slot, and the method comprises the following steps:

starting a milling cutter, and drilling holes on the bottom of the first groove;

moving the milling cutter along a circumferential direction of the first groove such that the first attachment hole is formed on a bottom of the first groove.

7. The method for manufacturing the metal blind slot of the circuit board according to any one of the claims 4 to 6, wherein the rotation speed of the milling cutter is 30 to 35kr/min, the cutting speed of the milling cutter during drilling is 1 to 5mm/sec, and the feeding speed of the milling cutter is 7 to 22 mm/sec.

8. The method for manufacturing the metal blind slot of the circuit board according to any one of claims 1 to 6, wherein the steps further comprise:

copper deposition is carried out on the circuit board;

and carrying out board surface electroplating on the circuit board.

9. The method for manufacturing the metal blind slot of the circuit board according to claim 8, wherein the step of plating the surface of the circuit board further comprises:

and baking the circuit board.

10. The method for manufacturing the metal blind slot of the circuit board according to claim 8, wherein the step of performing copper deposition on the circuit board further comprises:

and carrying out deburring treatment on the circuit board.

Technical Field

The invention relates to the technical field of circuit board processing, in particular to a manufacturing method of a metal blind slot of a circuit board.

Background

With the rapid development of the electronic industry, the demand of the circuit board is increasing, and the requirements on the circuit board and the corresponding functions are also increasing. At present, the design of a circuit board mainly tends to be complicated and intensive, and a large number of components are integrated on the circuit board so as to realize various functions. However, as a large number of components are integrated on a wiring board, the space on the wiring board becomes extremely crowded. In order to enlarge the installation space on the circuit board, a metal blind slot, i.e., a power amplifier slot, is usually formed on the circuit board, and the component is installed in the power amplifier slot to reduce the congestion degree on the circuit board.

The traditional metal blind slot processing technology generally slots a circuit board firstly; and after slotting, sequentially carrying out copper deposition and electroplating processes on the circuit board. However, in the electroplating process, the plating layer formed in the groove usually peels off the substrate, which leads to the overall degradation of the quality of the circuit board and seriously affects the delivery period of the product.

Disclosure of Invention

Therefore, it is necessary to provide a method for manufacturing a metal blind slot of a circuit board, which can effectively enhance the adhesion between the plating layer and the substrate in the slot, improve the problem of plating layer peeling, and improve the overall quality of the circuit board.

The technical scheme is as follows:

a method for manufacturing a metal blind slot of a circuit board comprises the following steps: arranging a region to be grooved on the circuit board; after the arrangement, slotting is carried out in the area to be slotted, so that a blind slot is formed on the circuit board; after grooving, forming a hole in the bottom of the blind groove, so that a first attachment hole is formed in the bottom of the blind groove, wherein the first attachment hole extends along the circumferential direction of the blind groove.

In the manufacturing method of the metal blind slot of the circuit board, the area to be slotted is arranged on the circuit board, and the area to be slotted is slotted, so that the blind slot is formed on the circuit board; after slotting, perforating the bottom of the blind slot to form a first attachment hole at the bottom of the blind slot, so that metal copper can be attached to the first attachment hole when the circuit board is subjected to copper deposition; after the metal copper adheres to, the face is electroplated again to the circuit board, and at this moment, the cladding material that blind groove bottom formed can be connected with the metal copper in the first attachment hole, like this, through the metal copper in the first attachment hole, improve the adhesion between the base material in cladding material and the blind groove for cladding material and blind groove closely combine, reduce the incidence that the cladding material peeled off from the base material, guarantee that the product can normally be delivered goods. Because first attached hole extends the setting along the circumference of blind groove, consequently, the first attached hole of this scheme is the loop configuration for can form annular metal copper in the heavy copper in-process in the first attached hole, greatly increased the area of connection between metal copper and the cladding material, further improved the power of attaching between cladding material and the base material of blind inslot, make cladding material and blind groove combine closely more, greatly improved the cladding material and peeled off the problem, be favorable to improving the whole quality of circuit board.

The principle and effect of the invention will be further explained by combining the above scheme:

in one embodiment, the width W of the first attaching hole is 0.4mm to 0.8 mm; the depth h of the first attachment hole is 0.1 mm-0.5 mm.

In one embodiment, after the setting, slotting in the area to be slotted to form a blind slot on the circuit board includes: dividing the area to be grooved into a main groove area and an auxiliary groove area surrounding the edge of the main groove area; grooving in the main groove area to form a first groove in the main groove area; and grooving in the auxiliary groove area, so that a second groove is formed in the auxiliary groove area, wherein the first groove and the second groove form the blind groove.

In one embodiment, the step of grooving in the main groove region so that a first groove is formed in the main groove region includes: acquiring a first processing position in the main groove area; starting the milling cutter, and drilling on the first machining position to enable the hole depth to be a first preset depth value; after drilling, moving the milling cutter in a direction away from the first machining position by a first preset distance value, and controlling the first preset distance value to be smaller than or equal to the diameter of the milling cutter; after moving a first preset distance value, moving the milling cutter around the first machining position, milling the main groove area, and enabling the machining track of the milling cutter to be annular; and after the annular movement, repeatedly moving the milling cutter by the first preset distance value and moving around the first machining position until the base material in the main groove area is milled away.

In one embodiment, the step of slotting in the secondary slot region such that a second groove is formed in the secondary slot region includes: selecting more than two second processing stations at intervals in the auxiliary groove area; starting the milling cutter, and drilling on the second machining position to enable the hole depth to be a second preset depth value; after drilling, moving the milling cutter in the direction away from the second machining position by a second preset distance value, and controlling the second preset distance value to be smaller than or equal to the diameter of the milling cutter; after moving a second preset distance value, moving the milling cutter around the second machining position, milling the auxiliary groove area, and enabling the machining track of the milling cutter to be annular; and after the annular movement, repeatedly moving the milling cutter by the second preset distance value and moving around the second machining position until the base material in the auxiliary groove area is milled away.

In one embodiment, after the slotting, the step of drilling a hole on the bottom of the blind slot so as to form a first attachment hole on the bottom of the blind slot includes: starting a milling cutter, and drilling holes on the bottom of the first groove; moving the milling cutter along a circumferential direction of the first groove such that the first attachment hole is formed on a bottom of the first groove.

In one embodiment, the rotation speed of the milling cutter is 30-35 kr/min, the drilling cutting speed of the milling cutter is 1-5 mm/sec, and the feeding speed of the milling cutter is 7-22 mm/sec.

In one embodiment, the steps further include: copper deposition is carried out on the circuit board; and carrying out board surface electroplating on the circuit board.

In one embodiment, the step of plating the circuit board further comprises: and baking the circuit board.

In one embodiment, the step of copper-plating the circuit board further includes: and carrying out deburring treatment on the circuit board.

Drawings

Fig. 1 is a first flowchart of a method for manufacturing a metal blind slot of a circuit board according to an embodiment of the present invention;

fig. 2 is a flow chart of a method for manufacturing a metal blind slot of a circuit board according to an embodiment of the present invention;

fig. 3 is a third flowchart of a method for manufacturing a metal blind slot of a circuit board according to an embodiment of the present invention;

fig. 4 is a fourth flowchart of a method for manufacturing a metal blind slot of a circuit board according to an embodiment of the present invention;

fig. 5 is a flow chart of a method for manufacturing a metal blind slot of a circuit board according to an embodiment of the present invention;

fig. 6 is a flowchart of a sixth method for manufacturing a metal blind slot of a circuit board according to an embodiment of the present invention;

FIG. 7 is a schematic diagram illustrating the milling of the primary and secondary trough sections according to an embodiment of the present invention;

FIG. 8 is a top view of a blind slot structure according to an embodiment of the present invention;

FIG. 9 is a cross-sectional view of a circuit board with an unprocessed first attachment hole in accordance with one embodiment of the present invention;

fig. 10 is a cross-sectional view of a circuit board after plating on a board surface according to an embodiment of the invention.

Description of reference numerals:

100. a region to be grooved; 110. a main trough area; 111. a first processing station; 120. a secondary trough region; 121. a second processing station; 200. a blind groove; 210. a first groove; 220. a second groove; 230. a first attachment hole; 300. a circuit board; 400. and (7) plating.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings and the detailed description. It should be understood that the detailed description and specific examples, while indicating the scope of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not represent the only embodiments.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The terms "first" and "second" used herein do not denote any particular order or quantity, but rather are used to distinguish one element from another.

In an embodiment, referring to fig. 1, fig. 7, fig. 8, fig. 9 and fig. 10, a method for manufacturing a metal blind via of a circuit board includes the following steps:

s10, arranging a region 100 to be grooved on the circuit board 300;

s20, after the arrangement, slotting in the area to be slotted 100 to form a blind slot 200 on the circuit board 300;

after the slot is opened at S30, a hole is opened on the bottom of the blind slot 200, so that a first attachment hole 230 is formed on the bottom of the blind slot 200, wherein the first attachment hole 230 extends along the circumferential direction of the blind slot 200.

In the manufacturing method of the metal blind slot of the circuit board, the area 100 to be slotted is arranged on the circuit board 300, and the area 100 to be slotted is slotted, so that the blind slot 200 is formed on the circuit board 300; after slotting, forming a hole at the bottom of the blind slot 200, so that a first attachment hole 230 is formed at the bottom of the blind slot 200, and thus, when the circuit board 300 is subjected to copper deposition, metal copper is attached to the first attachment hole 230; after the metal copper is attached, the circuit board 300 is electroplated on the surface, and at the moment, the plating layer 400 formed at the bottom of the blind groove 200 is connected with the metal copper in the first attachment hole 230, so that the attachment force between the plating layer 400 and the base material in the blind groove 200 is improved through the metal copper in the first attachment hole 230, the plating layer 400 is tightly combined with the blind groove 200, the occurrence rate of stripping the plating layer 400 from the base material is reduced, and the product can be normally delivered. Because first attachment hole 230 extends along the circumference of blind groove 200 and sets up, consequently, first attachment hole 230 of this embodiment is the loop configuration, make in first attachment hole 230 can form annular metallic copper at heavy copper in-process, greatly increased the area of connection between metallic copper and cladding material 400, further improved the power of attaching between cladding material 400 and the base material in the blind groove 200, make cladding material 400 and blind groove 200 combine closely more, greatly improved cladding material 400 and peeled off the problem, be favorable to improving the whole quality of circuit board 300.

It should be noted that the specific shape of the region to be grooved 100 in this embodiment needs to be determined according to the specific shape of a specific component, where the region to be grooved 100 may be a circle, a square, a rectangle, a pentagon, a hexagon, and the like.

It should be further noted that the electroless copper plating is an autocatalytic redox reaction: firstly, the surface of the insulating base material is treated by an activating agent to adsorb an active particle, usually metal palladium particles, copper ions are firstly reduced on the active metal palladium particles, and the reduced metal copper crystal nuclei become a catalytic layer of the copper ions, so that a metal copper layer is attached in the holes. The electroplating of the plate surface is to reduce and deposit metal ion copper on the surface of the plated piece by an electrochemical method to form a uniform and bright metal surface layer.

Further, referring to fig. 8 and 10, the width W of the first attachment hole 230 is 0.4mm to 0.8 mm. If the width of the first adhesion hole 230 is too small, the surface tension in the first adhesion hole 230 is too large, so that metal ions cannot smoothly enter the first adhesion hole 230, and a complete metal copper layer cannot be formed in the first adhesion hole 230, so that the connection strength between the metal copper layer and the plating layer 400 is reduced, and the adhesion of the plating layer 400 in the groove is seriously affected; if the width of the first attachment hole 230 is too large, the overall structure of the circuit board 300 is affected, and therefore, the width of the first attachment hole 230 is limited to 0.4mm to 0.8mm in this embodiment, and a stable metal copper layer is formed in the first attachment hole 230 on the premise that the structure of the product is not affected. Meanwhile, the depth h of the first attachment hole 230 is 0.1mm to 0.5 mm. Therefore, the depth of the first adhesion hole 230 is reasonably controlled, so that the combination between the metal copper layer and the hole wall of the first adhesion hole 230 is more stable, and the combination force between the plating layer 400 and the base material is favorably improved. Specifically, in the present embodiment, the width W of the first attachment hole 230 is 0.6 mm; the depth h of the first attachment hole 230 is 0.2 mm.

In one embodiment, referring to fig. 2, fig. 7 and fig. 8, after the step of performing the grooving in the to-be-grooved region 100 to form the blind groove 200S20 on the circuit board 300, the step includes:

s21, dividing the area 100 to be grooved into a main groove area 110 and an auxiliary groove area 120 surrounding the edge of the main groove area 110;

s22, slotting in the main slot area 110 to form a first groove 210 in the main slot area 110;

s23, forming a groove in the sub-groove region 120, such that a second groove 220 is formed in the sub-groove region 120, wherein the first groove 210 and the second groove 220 form a blind groove 200.

Therefore, the slotting process of the present embodiment is divided into two steps, i.e. slotting the main slot area 110; secondly, the secondary groove area 120 is grooved. Since the sub-slot region 120 is disposed around the edge of the main slot region 110, before the slot is opened, the to-be-slotted region 100 is divided, and the to-be-slotted region 100 is divided into a middle portion and a peripheral portion, so that different portions of the to-be-slotted region 100 are subjected to different slot processes. In the embodiment, the middle part and the peripheral part of the slotting region are respectively and independently processed, so that the middle part can be quickly slotted, and the peripheral part can be accurately slotted. Thus, the embodiment not only ensures the slotting speed of the area to be slotted 100, but also ensures the slotting precision of the area to be slotted 100.

Specifically, referring to fig. 7, the to-be-grooved area 100 is square, the main groove area 110 is circular, and the auxiliary groove area 120 is the area obtained by subtracting the main groove area 110 from the to-be-grooved area 100. Meanwhile, the diameter of the main slot area 110 is the width of the area to be slotted 100, and the center of the main slot area 110 overlaps with the center of the area to be slotted 100.

Further, referring to fig. 3 and fig. 7, the step of performing a groove opening in the main groove area 110 to form the first groove 210S22 in the main groove area 110 includes:

s221, acquiring a first processing position 111 in the main groove area 110;

s222, starting a milling cutter, and drilling on the first machining position 111 to enable the hole depth to be a first preset depth value;

s223, after drilling, moving the milling cutter in the direction away from the first machining position 111 by a first preset distance value, and controlling the first preset distance value to be smaller than or equal to the diameter of the milling cutter;

s224, after the milling cutter moves by the first preset distance value, the milling cutter moves around the first machining position 111 to mill the main groove area 110, and the machining track of the milling cutter is annular;

and S225, after the annular movement, repeatedly moving the milling cutter by a first preset distance value and moving the milling cutter around the first processing station 111 until the base material in the main groove area 110 is milled away.

Therefore, in the embodiment, the grooving process of the main groove area 110 is specifically defined, and first, the first processing station 111 is determined in the main groove area 110; drilling the first machining position 111 to enable the hole depth to reach a first preset depth; then, the milling cutter is deviated by a first preset distance and is circularly moved and milled around the first machining position 111; finally, the milling cutter is repeatedly shifted and annularly moved for milling, so that the main groove area 110 is processed layer by layer from inside to outside according to annular milling, and the base material in the main groove area 110 is smoothly milled.

Specifically, the ring shape of the present embodiment is circular. Meanwhile, in order to achieve better milling in the main groove area 110, the center of the main groove area 110 is used as a first processing position 111. Such as: when the main groove area 110 is circular, the first processing station 111 is the center of the main groove area 110; when the main groove area 110 has a square shape, the first processing station 111 is a diagonal intersection of the main groove area 110, and the like.

It should be noted that, the first preset distance value is smaller than or equal to the diameter of the milling cutter, which is beneficial to ensuring that no substrate remains between two adjacent layers of rings in the milling process of the milling cutter rings, so that the bottom of the first groove 210 is ensured to be more flat, and a complete and flat plating layer 400 can be formed in the first groove 210. Meanwhile, the burr amount in the first groove 210 is reduced, the workload of operators is greatly reduced, and the processing efficiency of products is improved. In addition, the first preset depth value can be specifically set according to the depth of the actual component.

In one embodiment, referring to fig. 4 and 7, the step of slotting in the sub-slot region 120 to form the second slot 220S23 in the sub-slot region 120 includes:

s231, selecting more than two second processing stations 121 at intervals in the auxiliary groove area 120;

s232, starting the milling cutter, and drilling on the second machining position 121 to enable the hole depth to be a second preset depth value;

s233, after drilling, moving the milling cutter in the direction away from the second machining position 121 by a second preset distance value, and controlling the second preset distance value to be smaller than or equal to the diameter of the milling cutter;

s234, moving the milling cutter around the second machining position 121 after the second preset distance value is moved, milling the auxiliary groove area 120, and enabling the machining track of the milling cutter to be annular;

and S235, after the circular movement, repeatedly moving the milling cutter by a second preset distance value and moving the milling cutter around the second machining position 121 until the base material in the auxiliary groove area 120 is milled away.

Therefore, in the embodiment, the slotting process of the sub-slot region 120 is specifically limited, and first, the second machining position 121 is determined in the sub-slot region 120; drilling the second machining position 121 to enable the hole depth to reach a second preset depth; then, shifting the milling cutter by a second preset distance, and performing annular moving milling around a second processing station 121; finally, the milling cutter is repeatedly shifted and annularly moved for milling, so that the auxiliary groove area 120 is processed layer by layer from inside to outside according to annular milling, and the base material in the auxiliary groove area 120 is smoothly milled. Meanwhile, the auxiliary groove area 120 of the present embodiment also adopts a ring milling manner, so that the side wall of the processed blind groove 200 is more smooth, and the phenomenon that the plating layer 400 is difficult to be combined on the side wall of the blind groove 200 due to the corner on the side wall of the blind groove 200 is avoided.

Specifically, the ring shape of the present embodiment is circular. Meanwhile, when the shape of the region 100 to be grooved is square and the shape of the main groove region 110 is circular, the number of the second processing stations 121 is four, which correspond to four corners of the region 100 to be grooved respectively, and the second processing stations 121 are: and connecting the circle center of the main groove area 110 with the angle of the area to be grooved 100, wherein the connecting line is intersected with the edge of the main groove area 110, and the obtained intersection point is a second processing position 121. In addition, the first attachment hole 230 is an annular circle, and the first attachment hole 230 is concentrically arranged with the main slot area 110.

It should be noted that the second preset distance value is smaller than or equal to the diameter of the milling cutter, and similarly, it is ensured that no base material remains between the two adjacent rings in the milling process of the milling cutter ring. Meanwhile, the second preset depth value can be specifically set according to the depth of the actual component.

In one embodiment, referring to fig. 5 and 7, after the slot is opened, a hole is formed on the bottom of the blind slot 200, so that the step of forming the first attachment hole 230S30 on the bottom of the blind slot 200 includes:

s31, starting the milling cutter, and opening a hole on the bottom of the first groove 210;

s32, the milling cutter is moved along the circumference of the first groove 210 so that a first attachment hole 230 is formed on the bottom of the first groove 210. Therefore, the plating layer 400 in the first groove 210 is bonded with the substrate more tightly, and the problem of stripping of the plating layer 400 in the first groove 210 is greatly improved.

Further, after the slotting, the step of perforating the bottom of the blind slot 200 so as to form the first attachment hole 230S30 on the bottom of the blind slot 200 further includes:

s33, forming a hole on the bottom of the second groove 220;

s34, moving the milling cutter along the circumferential direction of the second groove 220 so that a second attachment hole is formed on the bottom of the second groove 220.

Therefore, in this embodiment, in addition to the first attachment hole 230 in the first groove 210, the second attachment hole is also provided in the second groove 220, so that the middle part and the peripheral part of the plating layer 400 in the blind groove 200 are both connected with the copper metal in the attachment hole, and thus the plating layer 400 is bonded with the substrate more tightly, and the quality of the circuit board 300 is further improved.

In one embodiment, the rotation speed of the milling cutter is 30-35 kr/min, the cutting speed of the milling cutter during drilling is 1-5 mm/sec, and the feeding speed of the milling cutter is 7-22 mm/sec. Therefore, the processing of the blind groove 200 is smoother by controlling the reasonable parameters of the milling cutter.

In one embodiment, please refer to fig. 6 and 10, the steps further include:

s40, carrying out copper deposition on the circuit board 300;

s50, plating the circuit board 300.

Therefore, when the first attachment hole 230 is formed in the circuit board 300, the circuit board 300 is subjected to the copper deposition and the board surface plating processes, respectively. Thus, when the circuit board 300 is subjected to copper deposition, the first attachment hole 230 is attached with copper; after the metal copper is attached, the circuit board 300 is electroplated on the surface, and at the moment, the plating layer 400 formed at the bottom of the blind groove 200 is connected with the metal copper in the first attachment hole 230, so that the attachment force between the plating layer 400 and the base material in the blind groove 200 is improved through the metal copper in the first attachment hole 230, the plating layer 400 is tightly combined with the blind groove 200, the occurrence rate of stripping the plating layer 400 from the base material is reduced, and the product can be normally delivered. Because first attachment hole 230 extends along the circumference of blind groove 200 and sets up, consequently, first attachment hole 230 of this embodiment is the loop configuration, make in first attachment hole 230 can form annular metallic copper at heavy copper in-process, greatly increased the area of connection between metallic copper and cladding material 400, further improved the power of attaching between cladding material 400 and the base material in the blind groove 200, make cladding material 400 and blind groove 200 combine closely more, greatly improved cladding material 400 and peeled off the problem, be favorable to improving the whole quality of circuit board 300.

It should be noted that the electroless copper plating is an autocatalytic redox reaction: firstly, the surface of the insulating base material is treated by an activating agent to adsorb an active particle, usually metal palladium particles, copper ions are firstly reduced on the active metal palladium particles, and the reduced metal copper crystal nuclei become a catalytic layer of the copper ions, so that a metal copper layer is attached in the holes. The electroplating of the plate surface is to reduce and deposit metal ion copper on the surface of the plated piece by an electrochemical method to form a uniform and bright metal surface layer.

Specifically, the copper deposition degumming rate of the embodiment is 0.1mg/cm²～0.3mg/cm²The copper deposition rate is 0.3-0.6 μm. Meanwhile, in the plate surface electroplating process, the current density is 6-12 ASF, the thickness of the electroplated copper is 7-12 μm, and the electroplating time is 30 min.

Further, before the step S50 of plating the board surface of the circuit board 300, the method further includes:

s60, baking the circuit board 300. The circuit board 300 of this embodiment after to the heavy copper toasts, copper crystal nucleus after the heavy copper of activation for the face electroplating process, with copper crystal nucleus after the activation as the basis, at the massive metal copper of blind groove 200 bottom deposit, be convenient for form stable in structure's cladding material 400. In the embodiment, a vertical oven is adopted in the baking process, the baking temperature is 120-150 ℃, and the baking time is 1-3 hours.

In one embodiment, the step of performing the copper deposition S40 on the circuit board 300 further includes:

s70, the wiring board 300 is deburred. Thus, the drill cuttings in the blind groove 200 and burrs on the blind groove 200 and the attachment holes are removed by deburring to prepare for copper deposition.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.