CN109257881B

CN109257881B - Method for manufacturing alignment target of circuit substrate

Info

Publication number: CN109257881B
Application number: CN201811248303.XA
Authority: CN
Inventors: 肖安云; 王俊
Original assignee: Shenzhen Kinwong Electronic Co Ltd
Current assignee: Shenzhen Kinwong Electronic Co Ltd
Priority date: 2018-10-25
Filing date: 2018-10-25
Publication date: 2020-05-12
Anticipated expiration: 2038-10-25
Also published as: CN109257881A

Abstract

The invention provides a method for manufacturing a circuit substrate alignment target, which comprises the following steps: s1, providing a circuit substrate, wherein the circuit substrate is provided with a target midpoint on the operation plate surface; s2, around the first ring hole … … Nth ring hole (N is more than or equal to 2) of beating N ring cover settings in proper order, around beat earlier through laser when the ring hole in the operation face punch the formation with the laser hole that the target mid point interval set up, and with the centre of a circle in laser hole arrives the distance of target mid point is for around beating the radius and encircle and punch, in order to form the ring hole, first ring hole … … the Nth ring hole forms annular target hole altogether. According to the invention, multi-circle winding is carried out by laser, the ring diameter of the target hole is increased, the laser energy does not need to be too large, the target hole is not easy to fill and level during copper plating, the roundness is improved, the target-grabbing recognition rate and accuracy are improved, errors caused by mechanical vibration are avoided, and the requirement of exposure precision is met.

Description

Method for manufacturing alignment target of circuit substrate

Technical Field

The invention belongs to the technical field of printed circuit boards, and particularly relates to a method for manufacturing a circuit substrate alignment target.

Background

In the existing printed circuit board production, LDI (laser direct imaging, which is called laser direct imaging technology in chinese) is used in the exposure process in the circuit board process, and the difference from the traditional negative film contact exposure method is that the traditional exposure is to transfer the image to the circuit board by irradiating the negative film through a mercury lamp, and LDI is to directly image the circuit on the circuit board by using a laser scanning method, and before imaging, alignment is required through a target.

With the development of miniaturization and high density of circuit boards, the precision requirement of the circuit boards on photoetching alignment is higher and higher, and the alignment precision directly influences the quality of the substrate. The target aligned by LDI exposure generally has the following two modes: one is that after the lamination, the X-ray is used for milling a target hole positioning hole, the target hole is used for positioning during LDI exposure, the alignment error of the method is more than 0.10mm, and when the aperture of the target hole is less than 50um, the target can not meet the exposure precision requirement; in addition, a target is formed by laser drilling, but the target drilled by the laser is easily filled due to small aperture in the electroplating process, so that the target-grabbing recognition rate of the LDI during the exposure operation is poor or the target-grabbing cannot be positioned, the production efficiency is affected, and the product rejection rate is high.

Disclosure of Invention

The invention aims to provide a method for manufacturing a circuit substrate alignment target, and aims to solve the technical problem that the target is easy to fill and difficult to identify in the prior art.

The invention is realized in this way, a method for manufacturing a circuit substrate alignment target comprises the following steps:

s1, providing a circuit substrate, wherein one board surface of the circuit substrate is an operation board surface, and the circuit substrate is provided with a target midpoint on the operation board surface;

s2, winding and beating N first circular ring holes … … and Nth circular ring holes (N is more than or equal to 2) which are sequentially arranged in a ring sleeve:

winding a first circular ring hole: firstly, punching holes in the operation board surface by laser to form first laser holes arranged at intervals with the middle point of the target, forming a first winding path by taking the distance from the circle center of the first laser hole to the middle point of the target as a winding radius, and then performing surrounding punching along the first winding path by laser to form a first circular ring hole;

……

and (2) drilling an Nth circular ring hole, firstly drilling a hole on the operation plate surface through laser to form an Nth laser hole arranged at an interval with the midpoint of the target, forming an Nth drilling path by taking the distance from the circle center of the Nth laser hole to the midpoint of the target as a drilling radius, and then drilling the Nth drilling path in a surrounding way through laser to form the Nth circular ring hole, wherein the first circular ring hole … … and the Nth circular ring hole form an annular target hole together.

Further, the nth laser holes of the first laser holes … … are all blind holes.

Furthermore, the circuit substrate is set as a substrate layer and a copper layer coated on one surface of the substrate layer, so that the operation surface and the copper layer are respectively positioned on two sides of the substrate layer.

Further, the first laser via … … nth laser via is made to penetrate through the substrate layer to the copper layer.

Further, the first circular ring … … and the nth circular ring are sequentially overlapped and wound in the direction from the outer diameter to the inner diameter.

Further, the diameters of the nth circular ring holes of the first circular ring holes … … are the same.

Further, N is equal to 3 to 5.

Further, the diameter of the single laser hole is 0.075mm-0.15 mm.

Furthermore, the distance between the centers of two adjacent laser holes of each winding path is 0.03mm-0.05 mm.

Further, the diameter of the annular target hole is 0.15mm-0.3 mm.

Compared with the prior art, the invention has the technical effects that: the laser is used for performing multi-circle winding, N concentric ring holes with the center point of the target as the circle center, namely the first ring hole … … Nth ring hole, are formed, and the first ring hole … … Nth ring holes can be overlapped in pairs to form the target holes together. Compared with the target hole formed by the traditional mechanical drilling, the target hole formed by laser drilling has smaller error, avoids the error generated by mechanical vibration, meets the requirement of exposure precision and improves the accuracy of counterpoint target grabbing; secondly, the diameter of the target hole formed by the multi-circle winding is larger than that of any one single-circle winding circular ring hole, so that the target hole is not easy to fill and level during copper plating, the target hole is easy to identify, and the target grabbing identification rate is improved; in addition, the multi-circle winding of the small-energy laser to form the target hole with the large ring diameter can prevent the situation that the circuit substrate is broken down due to overlarge energy of the laser easily caused by the single-circle winding of the large-energy laser to form the target hole with the same ring diameter, and the liquid medicine is easy to remain in the hole and is difficult to dry when the circuit substrate is processed due to overlarge hole depth and uncontrollable hole diameter of the large-energy laser to form the target hole with different sizes, the roundness and the edge smoothness of the target hole are not high, and the multi-circle winding of the small-energy laser overcomes the defects, so that the hole diameter of the laser hole is controllable, and the roughness of the outer edge and the inner edge of the target hole is reduced due to the small and dense laser holes on the circular holes at the outer edge and the inner edge of the target hole, so that the edge of the target hole is smoother, the roundness is improved, and the alignment error is further reduced, the exposure accuracy is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments of the present invention or in the description of the prior art will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 illustrates a manufacturing step of a method for manufacturing an alignment target of a circuit substrate according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a first annular ring according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a second annular ring according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a third annular ring according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a target well structure provided by an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a circuit substrate according to an embodiment of the present invention;

description of reference numerals:

100. a targeting orifice; 101. a first laser via; 102. a second laser via; 103. a third laser via; 110. a first annular ring; 120. a second annular ring; 130. a third annular ring; 200. a circuit substrate; 201. a substrate layer; 202. a copper layer; 210. operation panel

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

Furthermore, the term "first" … … "nth" is used for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" … … "nth" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments.

Referring to fig. 1, the present invention provides a method for manufacturing a circuit board 200 alignment target, wherein the circuit board 200 alignment target is an annular target hole 100 formed by laser drilling through a laser drilling machine, and the method includes the following steps:

s1, providing a circuit board 200, where the circuit board 200 has two opposite board surfaces, one of the two board surfaces is an operation board surface 210, and the circuit board 200 has a target midpoint on the operation board surface 210. The target midpoint may be a real point, so that the laser beam drilling machine recognizes the target midpoint before drilling and then performs drilling with the recognized target midpoint as a reference point, or an imaginary point, which is a projection of a central point on the work board surface 210 referred to by a program for forming the circular target hole 100 that has been set in the laser beam drilling machine.

And S2, winding and punching N circular ring holes which are sequentially arranged in the ring sleeve. The laser can punch a hole on the operation board surface 210 to form a laser hole, the hole is punched in a surrounding manner by taking the center point of the target as the center of a circle to form a plurality of overlapped laser holes, the circular ring holes are formed by the laser holes surrounding the center point of the target by 360 degrees, namely the circular ring holes, and the circular ring holes are named as a first circular ring hole 110 … … (N is greater than or equal to 2) and are at least wound and punched in a surrounding manner. The term "ring sleeve" as used herein means that each of the circular ring holes is a concentric circle, and two adjacent circular ring holes are overlapped but not overlapped, i.e. the diameter of a new circular ring hole formed by the ring sleeve of two adjacent circular ring holes is smaller than the sum of the diameters of the two circular ring holes.

Preferably, the laser holes are identical in size, and the ring diameters of the circular holes are identical in size, that is, the ring diameters of the first circular ring hole 110 … … and the nth circular ring hole are all identical, so as to predict the number of winding turns and control the ring diameter size of the target hole 100 to be finally wound. In the embodiment of the invention, the diameter of a single laser hole is 0.075mm-0.15mm, and the distance between the centers of two adjacent laser holes on each circular ring hole is 0.03mm-0.05 mm.

Referring to fig. 2 to 5, the method for winding the first circular ring hole 110 includes: firstly, punching holes on the operation board surface 210 by laser to form first laser holes 101 arranged at intervals with the middle point of the target, forming a first winding path by taking the distance from the circle center of the first laser hole 101 to the middle point of the target as a winding radius, and then performing surrounding punching along the first winding path by laser to form the first circular ring hole 110;

……

similarly, the winding method of the Nth circular ring hole comprises the following steps: the working plate surface 210 is punched by laser to form an Nth laser hole arranged at an interval with the middle point of the target, an Nth winding path is formed by taking the distance from the circle center of the Nth laser hole to the middle point of the target as a winding radius, and then the Nth winding path is punched by laser in a surrounding manner to form the Nth circular ring hole.

Specifically, the first laser holes 101 … … and the nth laser holes are all blind holes to prevent laser from breaking through to the lower layer.

It should be noted that the nth circular ring hole is a second or more circular ring holes formed in a winding manner, the first circular ring hole 110 … … represents N circular ring holes, all the circular ring holes are overlapped at least two by two, and N is greater than or equal to 2, that is, the target hole 100 is formed by overlapping at least two circular ring holes. Preferably, N is equal to 3, 4 or 5, i.e. the targeting orifice 100 is formed by the overlapping of three to five of the circular orifices. Fig. 2 to 5 illustrate the manufacturing method of each step of the target holes 100 by taking N equal to 3 as an example, fig. 2 illustrates the first circular ring hole 110 formed by winding and punching the first laser hole 101, fig. 3 illustrates the second circular ring hole 120 formed by winding and punching the second laser hole 102, fig. 4 illustrates the third circular ring hole 130 formed by winding and punching the third laser hole 103, and fig. 5 illustrates the target holes 100 formed by sequentially winding and punching the first circular ring hole 110, the second circular ring hole 120, and the third circular ring hole 130, wherein each of the target holes 100 overlaps with each other two by two, and each of the circular ring holes overlaps with each other.

Wherein the first circular ring hole 110 … … and the Nth circular ring hole together form a circular target hole 100. In the embodiment of the present invention, the annular diameter of the annular target hole 100 is 0.15mm to 0.3mm, wherein the inner diameter of the target hole 100 is 0.5 mm to 4.5mm, and the outer diameter is 0.8 mm to 5.1mm, so as to ensure that the target hole 100 is not filled without wasting productivity.

Referring to fig. 2 to 5, preferably, in the embodiment of the present invention, the first circular ring hole 110 to the nth circular ring hole are sequentially overlapped and wound along a direction from an outer diameter to an inner diameter, so as to prevent a miss-driving region due to uneven edges of adjacent laser holes when the laser holes are wound and connected.

The invention performs multi-circle winding through laser to form N concentric ring holes which take the center point of the target as the center, namely the Nth ring hole of the first ring hole 110 … …, and enables the Nth ring holes of the first ring hole 110 … … to be overlapped in pairs to form the target hole 100 together.

The target hole 100 formed by the traditional mechanical drilling has larger alignment error due to objective factors such as mechanical positioning, mechanical vibration and the like, and the target hole 100 formed by the laser drilling has the advantages that the mechanical vibration is avoided, the alignment error of a single hole is reduced, the roughness of the edge of a circular ring hole which is wound is reduced, the requirement on exposure precision can be met, and the accuracy of alignment target grabbing is improved.

In the laser drilling process, if the small-energy laser is used for single-circle winding, the ring diameter is small, so that the target hole 100 is easy to fill in a subsequent copper plating process, and the target hole 100 is difficult to identify, if the large-energy laser is used for single-circle winding so that the ring diameter is large, the target hole 100 is too deep or the circuit substrate 200 is directly punctured due to too large energy, and liquid medicine is easy to remain in the hole when the circuit substrate 200 is processed due to the too deep target hole 100, so that the liquid medicine is difficult to dry. The invention uses the laser with small energy for multi-circle winding, thereby not only avoiding the over-deep punching, but also increasing the aperture compared with the single-circle punching, so that the target hole 100 is not easy to fill and level in the electroplating process, thereby the target hole 100 is easy to identify, and the target-grasping identification rate is improved.

In addition, when the laser energy is too large, the aperture size of a single laser hole is not easy to control, the aperture sizes of all laser holes on the circular ring holes are different, the roundness and the edge smoothness of the target holes 100 are not high, and the defects are overcome by multi-circle winding of the low-energy laser.

Referring to fig. 6, in order to ensure that each laser hole is a blind hole, the circuit substrate 200 is set as a substrate layer 201 and a copper layer 202 coated on one surface of the substrate layer 201, such that the working surface 210 and the copper layer 202 are respectively located on two sides of the substrate layer 201. The copper layer 202 is preferably thick to prevent laser via breakdown of the circuit substrate 200. Preferably, both side surfaces of the substrate layer 201 are coated with copper layers 202, and the copper layer 202 on the working board surface 210 is thinner than the copper layer 202 on the other side surface, so that laser can penetrate through the copper layer 202 on the working board surface 210 and cannot penetrate through the copper layer 202 on the other board surface, thereby preventing damage to the lower circuit substrate 200.

The energy of the laser is preferably such that the first laser via 101 … …, the nth laser via, penetrates through the copper layer 202 of the work board 210 and the substrate layer 201 to the surface of the copper layer 202 of the other board.

The manufacturing method of the alignment target of the invention processes through the laser hole, not only overcomes the defect that the laser hole is easy to fill and level, but also reduces the alignment error and increases the target-grasping recognition rate. When the target is arranged on the circuit board, the method can overcome the defect that the position of the target hole 100 cannot be flexibly filled and adjusted by mechanical drilling, and can select the punching position corresponding to the exposure block and design the appropriate number of targets according to the actual expansion and contraction condition of the volume of the circuit board in practical application so as to improve the alignment degree of exposure.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. A method for manufacturing a circuit substrate alignment target is characterized by comprising the following steps:

s2, winding and beating N first circular ring holes … … and N circular ring holes which are sequentially arranged in a ring sleeve, wherein N is larger than or equal to 2:

……

the method comprises the steps of drilling an N-th circular ring hole, firstly drilling a hole on the operation plate surface through laser to form an N-th laser hole arranged at an interval with a target midpoint, forming an N-th circular drilling path by taking the distance from the center of the N-th laser hole to the target midpoint as a circular drilling radius, and then drilling the N-th circular drilling path in a surrounding mode through laser to form the N-th circular ring hole, wherein the first circular ring hole … … and the N-th circular ring hole form an annular target hole together, and the first circular ring hole … … has the same ring diameter of the N-th circular ring hole so as to control the size of the ring diameter of the target hole.

2. The method as claimed in claim 1, wherein the first laser holes … … and the Nth laser holes are all blind holes.

3. The method as claimed in claim 1, wherein the circuit substrate is a substrate layer and the copper layer is coated on a surface of the substrate layer, such that the working surface and the copper layer are respectively disposed on two sides of the substrate layer.

4. The method as claimed in claim 3, wherein the first laser via … … Nth laser via is formed through the substrate layer to the copper layer.

5. The method as claimed in claim 1, wherein the first annular ring … … and the Nth annular ring are sequentially overlapped and wound from the outer diameter to the inner diameter.

6. The method according to any one of claims 1 to 5, wherein N is equal to 3-5.

7. The method for fabricating the alignment target of the circuit substrate according to any one of claims 1 to 5, wherein the diameter of the single laser hole is 0.075mm to 0.15 mm.

8. The method as claimed in claim 7, wherein the distance between the centers of two adjacent laser holes of each of the winding paths is 0.03mm to 0.05 mm.

9. The method as claimed in any one of claims 1 to 5, wherein the annular target hole has a diameter of 0.15mm to 0.3 mm.