CN105764261A

CN105764261A - Circuit LDI exposure positioning method and application thereof

Info

Publication number: CN105764261A
Application number: CN201610176979.7A
Authority: CN
Inventors: 赖荣祥
Original assignee: BAICHENG TECHNOLOGY (KUNSHAN) Co Ltd
Current assignee: BAICHENG TECHNOLOGY (KUNSHAN) Co Ltd
Priority date: 2016-03-25
Filing date: 2016-03-25
Publication date: 2016-07-13

Abstract

The invention belongs to the technical field of printed circuit board (PCB) manufacture and relates to a circuit LDI exposure positioning method and application thereof. The circuit LDI exposure positioning method comprises steps of: forming a circular a machine drill target on the edge of a PCB when a through hole is drilled mechanically; forming a laser target around the machine drill target on the edge of the PCB when a blind hole is drilled by laser; and performing positioning according the center of the machine drill target and the center of the laser target while circuit LDI exposure is carried out. The circuit LDI exposure positioning method may take the position of the through hole and the position of the blind hole into consideration when determining a positioning point so as to enable the position of a circuit bonding pad to cover the through hole and the blind hole as much as possible and reduce a disability rate.

Description

Circuit LDI exposes localization method and application thereof

Technical field

The present invention relates to printed circuit board (PCB) manufacturing technology field, expose localization method and application thereof particularly to a kind of circuit LDI taking into account through hole and half hole site.

Background technology

The Chinese full name of LDI (laserdirectimaging) is laser direct imaging technology, for the exposure process in PCB (printed circuit board (PCB)) technique, being different in that conventional exposure is to be transferred on PCB by Hg lamp irradiation egative film by image with traditional egative film contact exposure method, LDI is directly by circuit imaging on PCB by the method for laser scanning.

Before circuit imaging, it is necessary to make through hole and blind hole on PCB, wherein through hole is machine drill hole, and its standard error is at 50～100 μm, and blind hole is laser hole, and its standard error is at 25～50 μm.Owing to the processing mode in two kinds of holes is different, so different targets can be formed, but two kinds of targets are generally arranged at diverse location in the prior art, and circuit LDI can only select one in two kinds of targets and position.Just because of this location mode cannot take into account the position in two kinds of holes, so can not predict whether side-play amount exceedes tolerance interval, the position being likely to occur line pad and certain pores after exposure is bad and makes whole PCB scrap.

Therefore, it is necessary to provide a kind of new method to solve the problems referred to above.

Summary of the invention

Present invention is primarily targeted at and provide a kind of circuit LDI taking into account through hole and half hole site to expose localization method.

The present invention is achieved through the following technical solutions above-mentioned purpose: a kind of circuit LDI exposes localization method, step includes: at the machine drill target that PCB edge molding is circular during power auger through hole, at the PCB edge forming ring laser target around described machine drill target when laser beats blind hole, circuit LDI exposure positions according to center and the laser target target center of described machine drill target simultaneously.

Concrete, described laser target includes the some circular wad cutter that annular is uniform.

Further, the quantity of described wad cutter is the integral multiple of 4.

Further, the diameter of described machine drill target is 4 ± 0.5mm, and described laser target target pole grid diameter is 6 ± 0.5mm, and the diameter of described wad cutter is 0.5 ± 0.1mm.

A kind of circuit LDI exposes the application of localization method, when the wire length at described machine drill target center and laser target center is more than 75 μm, it is judged that punch defective；When the wire length stating machine drill target center and laser target center is not more than 75 μm, it is judged that punch qualified and line between described machine drill target center and laser target center determine anchor point, then carries out circuit LDI exposure.

Further, it is judged that when punching qualified, described anchor point is 1～2:1 to distance and the anchor point at machine drill target center to the ratio of distances constant at laser target center.

Adopting technique scheme, technical solution of the present invention provides the benefit that:

1, circuit LDI of the present invention exposure localization method can take into account the position of through hole and blind hole when determining anchor point, the position of line pad thus can be made as far as possible to cover through hole and blind hole, reduce scrappage；

2, laser target is marked on and near even overlapping center, exposure can be made can to capture both centers with being formed in the nonoverlapping situation of machine drill target simultaneously；

3, wad cutter set-up mode makes laser target target center determine easily and accurately；

4, machine drill target and laser target target centre deviation can be used directly to and judge whether punching is qualified, can directly save exposure cost if defective；

5, the determination of anchor point more can consider laser target target precision, it is ensured that the higher blind hole of required precision is fallen in the middle of line pad.

Accompanying drawing explanation

Fig. 1 is the circuit LDI of the present invention schematic diagram exposing localization method；

Fig. 2 is the close-up schematic view of location A in Fig. 1.

In figure, numeral represents:

1-machine drill target；

2-laser target, 21-wad cutter；

O1-machine drill target center, O2-laser target center, O3-anchor point；

D1-machine drill target diameter, D2-wad cutter diameter, D3-pole grid diameter.

Detailed description of the invention

Below in conjunction with specific embodiment, the present invention is described in further detail.

As depicted in figs. 1 and 2, a kind of circuit LDI exposes localization method, step includes: at the machine drill target 1 that PCB edge molding is circular during power auger through hole, at the PCB edge forming ring laser target 2 around machine drill target 1 when laser beats blind hole, laser target 2 includes the some circular wad cutter 21 that annular is uniform, circuit LDI exposure positions according to the center O1 of machine drill target 1 and the center O2 of laser target 2 simultaneously, specific practice is determine an anchor point O3 on the line between machine drill target center O1 and laser target center O2, and the length of line between machine drill target center O1 to laser target center O2 is divided into 1～2:1 by anchor point O3.Although the figure non-overlapping of such machine drill target 1 and laser target 2, but both centers (O1,02) can close to even overlapping, so can grab both centers (O1,02) when exposure simultaneously, then the effect taking into account through hole with blind hole position is played, the position that thus can make line pad covers through hole and blind hole as far as possible, reduces scrappage.

As shown in Figure 2, because blind hole precision is higher in actual processing, it is easier to be biased to outside line pad, so anchor point O3 position after can taking midpoint between machine drill target center O1 and laser target center O2 more suitably near laser target center O2, thus can guarantee that the higher blind hole of required precision is fallen in the middle of line pad.

As in figure 2 it is shown, in the course of processing, machine drill target center O1 and laser target center O2 can obtain a line determined, when wire length is not more than 75 μm time, exposure can carry out compromise location, is now just necessary to continue exposing operation；If wire length is more than 75 μm, illustrate the position deviation of through hole and blind hole arrived greatly no matter exposure position how to adjust be impossible to qualified, then be exposed nonsensical again, thus can scrap in advance and expose cost to save.

As it is shown in figure 1, the quantity of wad cutter 21 is the integral multiple of 4.Such wad cutter 21 set-up mode makes to find four points to carry out orthogonal line in laser target 2 scope and then finds laser target center O2, wad cutter 21 is more many, the laser target center O2 lookup error possibility brought because of the skew of indivedual wad cutters 21 will reduce, it is determined that easily and accurately.

The diameter D1 of machine drill target 1 is 4 ± 0.5mm, and the pole grid diameter D3 of laser target 2 is 6 ± 0.5mm, and the diameter of wad cutter D2 is 0.5 ± 0.1mm.Experience have shown that machine drill target 1 and laser target 2 so arrange identification higher, to improving, exposure qualification rate is favourable.

Above-described is only some embodiments of the present invention.For the person of ordinary skill of the art, without departing from the concept of the premise of the invention, it is also possible to making some deformation and improvement, these broadly fall into protection scope of the present invention.

Claims

1. a circuit LDI exposes localization method, it is characterized in that step includes: at the machine drill target that PCB edge molding is circular during power auger through hole, at the PCB edge forming ring laser target around described machine drill target when laser beats blind hole, circuit LDI exposure positions according to center and the laser target target center of described machine drill target simultaneously.

2. circuit LDI according to claim 1 exposes localization method, it is characterised in that: described laser target includes the some circular wad cutter that annular is uniform.

3. circuit LDI according to claim 2 exposes localization method, it is characterised in that: the quantity of described wad cutter is the integral multiple of 4.

4. circuit LDI according to claim 2 exposes localization method, it is characterised in that: the diameter of described machine drill target is 4 ± 0.5mm, and described laser target target pole grid diameter is 6 ± 0.5mm, and the diameter of described wad cutter is 0.5 ± 0.1mmm.

5. the application exposing localization method for the arbitrary described circuit LDI of claim 1-4, it is characterised in that: when the wire length at described machine drill target center and laser target center is more than 75 μm, it is judged that punch defective；When the wire length stating machine drill target center and laser target center is not more than 75 μm, it is judged that punch qualified and line between described machine drill target center and laser target center determine anchor point, then carries out circuit LDI exposure.

6. circuit LDI according to claim 5 exposes the application of localization method, it is characterised in that: judge that when punching is qualified, the length of line between machine drill target center to laser target center is divided into 1～2:1 by described anchor point.