US20030056474A1

US20030056474A1 - Method of inspecting newly purchased or reground materials for making printed circuit boards

Info

Publication number: US20030056474A1
Application number: US09/962,088
Authority: US
Inventors: Chieh Szu Chung
Original assignee: KEY WARE ELECTRONICS CO Ltd
Current assignee: KEY WARE ELECTRONICS CO Ltd
Priority date: 2001-09-26
Filing date: 2001-09-26
Publication date: 2003-03-27

Abstract

A method of inspecting newly purchased or reground materials for making printed circuit board (PCB) includes the steps of receiving the materials; sending the received materials to an automatic optical inspection system, at where the materials are inspected and graded; sending the inspected and graded materials to a packing machine to be separately packed; storing the packed good materials in a warehouse or issuing them to a production line for use; sending the packed defective materials and the good materials that have been used for a period of time to a specified place for regrinding; inspecting the reground materials with the automatic optical inspection system again; and scraping the materials that are no longer regrindable. The method enables materials for making PCBs to be always maintained in an optimal working condition to ensure production of high-quality PCBs.

Description

BACKGROUND OF THE INVENTION

The present invention relates to a method of inspecting newly purchased and reground materials for making printed circuit boards, and more particularly to a material inspection method, in which materials for making printed circuit boards are inspected, graded, and separately packed; good materials are issued for use or stored in warehouse; defective materials and used and blunt materials are reground and inspected again; and materials that are no longer regrindable are scraped; so that materials sent to a production line for making the printed circuit boards are always maintained in an optimal working condition.

For the purpose of this specification, the materials for making printed circuit boards (PCBs) are mini-size bits used to drill holes on PCBs. Such bits become blunt after they have been used on a production line for a certain period of time. To ensure the accuracy of holes drilled on PCBs and the quality of wall surfaces of these holes, the blunt bits on the production line must be removed for regrinding, and the reground bits are subjected to inspection before they could be reused.

Currently, a PCB manufacturer would usually send the blunt bits to a contracted grinding factory. The bits are first visually inspected and then manually reground. The bits so treated are therefore not uniform in their quality. Since there are only limited labors, equipment and time available in the PCB manufacturer for inspecting the reground bits, the latter are normally checked through sampling inspection. The bits being so reground and sampling inspected would cause a lot of problems in the production line, such as burr edges and skew and/or expanded bores of holes on the PCBs drilled with these reground bits, broken bits, etc. These problems would result in lowered production efficiency and increased bad yield of PCBs.

It is therefore tried by the inventor to develop a method for inspecting materials for making PCBs, so that newly purchased materials could be automatically inspected and graded, good and defective materials could be separately packed, defective and used good materials could be reground and inspected again, and only materials that are no longer regrindable are scraped.

SUMMARY OF THE INVENTION

A primary object of the present invention is to provide a method of inspecting newly purchased and reground materials for making printed circuit boards (PCBs), so as to control the quality of the materials put on a production line for making the PCBs.

Another object of the present invention is to provide a method of inspecting newly purchased and reground materials for making printed circuit boards (PCBs), so that the materials are always maintained in an optimal working condition to produce high-quality PCBs and upgrade the good yield thereof.

A further object of the present invention is to provide a method of inspecting newly purchased and reground materials for making printed circuit boards (PCBs), so that less time, equipment, and labors are required in quality inspection to reduce manufacturing cost of PCBs.

To achieve the above and other objects, the method of the present invention for inspecting newly purchased and reground materials for making PCBs includes the steps of receiving the materials; sending the received materials to an automatic optical inspection system, at where the materials are inspected and graded; sending the inspected and graded materials to a packing machine to be separately packed; storing the packed good materials in a warehouse or issuing them to a production line for use; sending the packed defective materials and the good materials that have been used for a period of time to a specified place for regrinding; inspecting the reground materials with the automatic optical inspection system again; and scraping the materials that are no longer regrindable. The method enables materials for making PCBs to be always maintained in an optimal working condition to ensure production of high-quality PCBs.

BRIEF DESCRIPTION OF THE DRAWINGS

The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein [0009]
FIG. 1 is a flowchart showing steps included in the method of inspecting newly purchased or reground materials for making printed circuit boards according to the present invention; [0010]
FIG. 2 is a flowchart showing sub-steps included in the [0011] step 2 of the method of the present invention; and
FIG. 3 is a flowchart showing sub-steps included in the [0012] step 3 of the method of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Please refer to FIG. 1 that is a flowchart showing steps included in the method of the present invention for inspecting newly purchased or reground materials for making printed circuit boards (PCBs). As shown, the steps included in the method of the present invention are as follows: [0013]
Material receiving step [0014] 1: This step is a starting point in the method of the present invention, wherein newly purchased mini-size bits are received.
Inspecting step [0015] 2: The newly purchased mini-size bits received in step 1 are subjected to inspection, grading, and classification conducted through an automatic optical inspection system; the inspected bits are divided into good and defective ones; and data about the good and the defective bits are separately recorded.
Packing step [0016] 3: The inspected mini-size bits, either graded as good or defective ones in the step 2, are sent to a packing machine, at where recorded data about every good and the defective bits are read so that the bits are positioned into their respective containers and sequentially packed.
Issuing/warehousing step [0017] 4: The packed good bits are either stored in a warehouse or issued to a production line for use. After being used for a period of time, the good bits are sent to a specified place for regrinding in step 5.
Regrinding step [0018] 5: Defective bits detected in step 2 and packed in step 3 are directly sent to regrind in step 5. The reground materials, that is, the mini-size bits, are returned to step 2 and the same inspection procedures from step 2 to step 5 are repeated.
Scraping step [0019] 6: When the mini-size bits are no longer regrindable in step 5, they are scraped and removed from the production line.
With the above-described inspection steps included in the method of the present invention, materials issued to the production line for use could always be maintained in an optimal working condition to enable production of high-quality PCBs at largely increased good yield. Moreover, time, labor and equipment required to inspect the produced PCBs are also saved to largely reduce the manufacturing cost of the PCBs. [0020]
In the above-mentioned [0021] inspecting step 2, the automatic optical inspection system is an automatic inspection machine capable of distinguishing good bits from defective ones. Before the automatic inspection machine could be used to perform the inspection, preparatory works, such as setting outer diameter of the bit, selecting direction of containers used to hold the inspected materials, inputting container numbers, adjusting focus and power, etc., must be done. Please refer to FIG. 2 that is a flowchart showing sub-steps included in the step 2 of the method of the present invention.
The automatic optical inspection system executes automatic inspection of every bit one by one starting from the first bit (sub-step [0022] 21). The system will use a standard specification as a basis of the inspection (sub-step 22), and determines whether a bit being inspected is qualified or not (sub-step 23). When a bit passes the inspection, it is determined as a good material; a container number is then designated to it and data about it are added into data files of good materials (sub-step 24). The system would then continue the inspection of a next bit (sub-step 25). When a bit does not pass the inspection, it is determined as a defective material; a container number is then designated to it and data about it are added into data files of defective materials (sub-step 26). The system would then continue the inspection of a next bit (sub-step 25).
After the bit inspection, grading, and [0023] classification instep 2, the bits are separately automatically-packed in step 3. FIG. 3 is a flowchart showing sub-steps included in the step 3 of the inspection method of the present invention.
After the bits are inspected, graded, and classified, and data thereof are filed, the automatic inspection machine automatically transfers data about the good materials to the packing machine (sub-step [0024] 31). The packing machine would correspondingly receive data transferred from the automatic inspection machine to it (sub-step 32). Good bits are then packed and sent to the warehouse (step 4). On the other hand, data about the defective bits are manually transferred from the automatic inspection machine to the packing machine (sub-step 33). The packing machine would correspondingly receive data about the defective bits (sub-step 34). The defective bits are then packed into 10-piece packets (sub-step 35) for regrinding later (step 5).
The present invention has been described with a preferred embodiment thereof and it is understood that many changes and modifications in the described embodiment can be carried out without departing from the scope and the spirit of the invention that is intended to be limited only by the appended claims. [0025]

Claims

What is claimed is:

1. A method of inspecting newly purchased or reground materials for making printed circuit boards, comprising the following steps:

a. Receiving materials newly purchased for making printed circuit boards and putting them into a starting point in an inspection line;

b. Inspecting, grading, and classifying said newly purchased materials received in step “a” through an automatic optical inspection system, so that said materials are divided into good and defective ones; and separately recording data about said good and said defective materials;

c. Sending said good and said defective materials to a packing machine, at where recorded data about said good and said defective materials being read so that said good and said defective materials are positioned into their respective containers and sequentially packed;

d. Storing said good materials packed in step “c”, in a warehouse or issuing them to a production line for use; and, sending said good materials that having been used for a period of time to a specified place for regrinding;

e. Directly sending said defective materials detected in step “b” and packed in step “c” to said specified place for regrinding; and returning said reground materials to said automatic optical inspecting system in step “b” and repeating the same inspection procedures from step “b” to step “e”; and

f. Scraping said materials that are no longer regrindable in step 5 by directly removing them from said inspection line;

whereby said materials passing said steps “a” to “f” included in said inspection method are always maintained in an optimal working condition when they are put into a production line, enabling production of high-quality printed circuit boards and high yield of good products at less time, material, and labor for inspection and accordingly at largely reduced manufacturing cost.