OPTICAL SYSTEM FOR MEASURING THE DEPTH OF AN INNER LAYER OF A PRINTED CIRCUIT BOARD

Abstract

An optical system for measuring the depth of an inner layer of a PCB, includes a light source transmitter used to emit an incident light, a controller, a CCD lens module, a pellicle mirror module, a depth measuring device, a reflective mirror module set at one end of the depth measuring device at an angle of 45 degrees, and a processor. When the incident light is incident on the surface copper of the PCB, a first reflected light is generated to pass through the reflective mirror module and the pellicle mirror module to the CCD lens module, then, the depth measuring device starts to move in the PCB until the incident light is incident on the inner layer copper of the PCB to generate a second reflected light that passes through the reflective mirror module and the pellet mirror module to the CCD lens module.

Claims

1. An optical system for measuring the depth of an inner layer of a printed circuit board, comprising: a light source transmitter for emitting an incident light; a controller; a CCD lens module connected to and controlled by said controller; a pellicle mirror module connected to said CCD lens module, the incidence angle of said incident light on said pellicle mirror module being 45 degrees; a depth measuring device connected to and controlled by said controller, said depth measuring device and said pellicle mirror module being parallel and opposite to each other and moving in the same direction; a reflective mirror module connected to said depth measuring device, said reflective mirror module being set at one end of said depth measuring device at an angle of 45 degrees, so that the incident angle of said incident light passing through said pellicle mirror module and said reflective mirror module is 45 degrees; and a processor connected to and controlled by said controller, said processor being used to calculate relevant data; wherein when said incident light is incident on the surface copper of a printed circuit board, a first reflected light is generated, and the optical path of said first reflected light is to said CCD lens module via said reflective mirror module and said pellicle mirror module, next, said depth measuring device starts to move in the internal space of said printed circuit board until said incident light is incident on the inner layer copper of said printed circuit board to generate a second reflected light, and the optical path of said second reflected light is through said reflective mirror module and said pellicle mirror module to said CCD lens module; wherein said depth measuring device moves in the internal space of said printed circuit board until the distance from said incident light to said second reflected light generated by the inner layer copper of said printed circuit board is the critical length of drill-down; wherein when said CCD lens module receives said first reflected light, the depth measurement is to be started, which is the initial measurement state.

2. The optical system for measuring the depth of an inner layer of a printed circuit board as claimed in claim 1, wherein when said CCD lens module receives said second reflected light, the depth measurement is completed, which is the measurement completion state.

3. The optical system for measuring the depth of an inner layer of a printed circuit board as claimed in claim 1, wherein said controller controls said light source transmitter to emit said incident light, and said depth measuring device starts to measure and move according to said first reflected light received by said CCD lens module.

4. The optical system for measuring the depth of an inner layer of a printed circuit board as claimed in claim 1, wherein said controller controls said light source transmitter to emit said incident light, and controls said depth measuring device to stop measuring movement according to said second reflected light received by said CCD lens module.

5. The optical system for measuring the depth of an inner layer of a printed circuit board as claimed in claim 1, wherein said controller sends relevant data to said processor for processing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG. 1 is a schematic diagram of a drill and a printed circuit board in the prior art.

[0018] FIG. 2 is a schematic diagram of drilling down of the drill to the printed circuit board in the prior art.

[0019] FIG. 3 is a block diagram of the optical system for measuring the depth of an inner layer of a printed circuit board of the present invention.

[0020] FIG. 4 is a schematic diagram of the initial measurement state of the printed circuit board inner layer depth measurement optical system of the present invention.

[0021] FIG. 5 is a schematic diagram of the completed measurement state of the printed circuit board inner layer depth measurement optical system of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0022] In order to solve the problem that the drilling depth of the existing drill bits is difficult to determine, the inventor of the present invention has improved the existing products after years of research and development. The follow-up will introduce in detail how the present invention uses the optical system for measuring the depth of an inner layer of a printed circuit board to achieve the most efficient functional demands.

[0023] Please refer to FIGS. 3 to 5 at the same time, where FIG. 3 is a block diagram of the optical system for measuring the depth of an inner layer of a printed circuit board of the present invention, FIG. 4 is a schematic diagram of the initial measurement state of the printed circuit board inner layer depth measurement optical system of the present invention, and FIG. 5 is a schematic diagram of the completed measurement state of the printed circuit board inner layer depth measurement optical system of the present invention. The optical system 300 for measuring the depth of an inner layer of a printed circuit board comprises a light source transmitter 310, a controller 320, a CCD lens module 330, a pellicle mirror module 340, a depth measuring device 350, a reflective mirror module 360 and a processor 370. CCD is a charge-coupled device (abbreviation: CCD). The CCD lens module 330 is connected to and controlled by the controller 320. The pellicle mirror module 340 is connected to the CCD lens module 330. The depth measuring device 350 is connected to and controlled by the controller 320. The reflective mirror module 360 is connected to the depth measuring device 350. The processor 370 is connected to and controlled by the controller 320. The light source transmitter 310 is used to emit an incident light JL (visible light), and the incident angle of the incident light JL on the pellicle mirror module 340 is 45 degrees. The depth measuring device 350 and the pellicle mirror module 340 are parallel and opposite to each other and will move in the same direction when starting the formal measurement. The reflective mirror module 360 is set at one end of the depth measuring device 350 at an angle of 45 degrees, so that the incident angle of the incident light JL passing through the pellicle mirror module 340 and the reflective mirror module 360 is 45 degrees.

[0024] The working mechanism of the optical system 300 for measuring the depth of an inner layer of a printed circuit board of the present invention will be further described in detail below.

[0025] The controller 320 controls the light source transmitter 310 to emit incident light JL, and the depth measuring device 350 starts to measure and move according to the first reflected light RL1 received by the CCD lens module 330. That is to say, when the incident light JL is incident on the surface copper DK of the printed circuit board, the first reflected light RL1 will be generated, and its optical path is through the reflective mirror module 360 and the pellicle mirror module 340 to the CCD lens module 330. Next, the controller 320 controls the light source transmitter 310 to continue emitting the incident light JL and controls the depth measuring device 350 to stop the measurement movement according to the second reflected light RL2 received by the CCD lens module 330. That is to say, the depth measuring device 350 starts to move in the inner space of the printed circuit board until the incident light JL is incident on the inner layer copper EK of the printed circuit board to generate the second reflected light RL2, and its optical path is through the reflective mirror module 360 and the pellicle mirror module 340 to the CCD lens module 330.

[0026] It is worth mentioning that the depth measuring device 350 moves in the internal space of the printed circuit board until the distance from the incident light JL to the second reflected light RL2 generated by the inner layer copper EK of the printed circuit board is the critical length of drill-down L2, which is also the true and effective distance from the surface copper to the inner layer copper. This is more accurate and effective than any traditional measurement method. The controller 320 transmits the relevant data to the processor 370 for processing, and the processor 370 is used to calculate the relevant data to obtain the critical length of drill-down L2. When the CCD lens module 330 receives the first reflected light RL1, it means that the depth measurement is about to start, which is the initial measurement state. When the CCD lens module 330 receives the second reflected light RL2, it means that the depth measurement has been completed, which is the measurement completion state.

[0027] In summary, the optical system for measuring the depth of the inner layer of the printed circuit board provided by the present invention can achieve the following effects: [0028] 1. It can effectively and accurately measure the critical length of drill-down. [0029] 2. It can effectively eliminate residual copper to solve the adverse effects of electrical signals. [0030] 3. It can improve production efficiency and save costs.