KR101763768B1 - Target board for verifying the accuracy of X-ray Drill Holes - Google Patents

Abstract

Disclosed is a target board suitable for verifying machining accuracy of an X-ray drill hole. The target board is formed with target marks by performing drying/filming and etching on a copper-clad laminate (CCL) having a thickness equal to the thickness of a product obtained by hot pressing. Here, the target marks are formed with first to fourth concentric circles arranged with respect to a center point. The first concentric circle and the third concentric circle are formed of an epoxy region, and the second concentric circle and the fourth concentric circle are formed of a copper region. The first concentric circle is provided to recognize the center point of the X-ray drill, and the third concentric circle is formed to provide an error limit. The inner diameter of the third concentric circle is determined in consideration of the diameter of a bit used in the X-ray drill and the error limit.

Description

A target board for verifying the accuracy of X-ray drill hole machining (Target board for verifying the accuracy of X-ray Drill Holes)

The present invention relates to a method of manufacturing a printed circuit board, and more particularly, to a method of manufacturing a printed circuit board, and more particularly, to a method of manufacturing a printed circuit board using a target board in order to minimize defects due to hole- The present invention relates to a target board suitable for verification of an X-ray drill hole machining accuracy that can be verified.

X-ray drill processing on a printed circuit board (PCB) is a process of forming a hole as a reference point to be used in a post-process on a product molded through a hot press process .

1 is a view for explaining a multi lay up build (MLB) process for producing a printed circuit board.

First, the oxide process forms roughness on the copper surface. This is to strengthen the adhesion between the product and the raw material when forming the multi-layer substrate.

The lay-up process is configured to hot-press raw materials such as a copper film (copper foil) and an RCC (resin coated copper) to the PPG lay-up finished product.

The hot press process is for bonding and forming a lay-up product by applying a temperature, pressure and vacuum suitable for the kind and thickness of the raw material by a predetermined time.

The X-ray drill process is for machining the reference and orientation holes for the stack guide and laser point exposure of the product.

The trimming process is for removing resin and copper scrap that have flowed out to the outside after hot press.

Fig. 2 shows the position of the x-ray drilling hole.

Four out of the seven holes (referred to as guide holes) are laser drills and dry films (Dfy / Film, D / F), which are the next processes of Multi Layup Build. Is used as a guide hole which is a standard for the process of the product.

(CCL, PPG, Copper Foil), internal pattern, and number of cavities used in the process of a printed circuit board (PCB) product from the inner layer to the final layer (Inner Layer to Final Layer) Since the material and specification information are different, the degree of contraction is different.

In order to take a value close to the scale (X 0, Y 0) when the final product is manufactured, a scale of <Example (X 2,200 Y 1,600)> is applied at the time of manufacturing the inner layer (Inner Layer) Layer) to check the changing scale.

However, if holes are formed in the X-ray drill process and the holes are misaligned, it affects the product recognition in the following processes: Laser Drill and Dry Film (D / F) Therefore, accurate scale conversion for the layer is not performed.

Fig. 3 shows a defect example due to x-ray drilling processing.

Hole If the data of the product which is deviated from the hole is inputted into the laser drill machine, it can not be processed in the lower pad, resulting in a short defect.

Accordingly, there is a demand for a method capable of verifying the machining accuracy and stabilizing the quality of the guide hole when the guide hole is machined by an X-ray drill.

The present invention provides a method for verifying the accuracy of a product to be actually processed by processing a guide hole using a target board prepared to have a thickness similar to a product to be processed, .

Another object of the present invention is to provide a target board that is suitable for the above-described machining accuracy verification method.

A method for verifying machining accuracy according to the present invention for achieving the above object

Preparing a target board having a target mark by performing D / F and etching on a CCL having a thickness equal to the thickness of a product obtained by hot pressing;

Forming a guide hole in the target board by an X-ray drill;

Measuring a machining accuracy of the guide hole;

And a control unit.

Here, it is preferable to further include a step of resetting the machining conditions to reflect the measured machining accuracy.

According to another aspect of the present invention,

D / F and etching are performed on a CCL having a thickness equal to the thickness of a product obtained by hot pressing to form a target mark,

Here, the target marks include first to fourth concentric circles arranged on the basis of a center point,

The first concentric circle and the third concentric circle are composed of an epoxy region, the second concentric circle and the fourth concentric circle are composed of a copper region,

Wherein the first concentric circle is for recognizing a center point in X-ray drilling processing, the third concentric circle is for providing an error limit, and the inner diameter of the third concentric circle is a diameter of a bit used in the X- Is determined in consideration of an error limit.

The present invention is based on the verification of the processing accuracy of an X-ray drill. By recognizing a hole (hHole) which does not occur in a post-process, Laser Hole deviations and short due to pattern shift) can be expected to be reduced.

1 is a view for explaining a multi lay up build (MLB) process for producing a printed circuit board.
Fig. 2 shows the position of the x-ray drilling hole.
Fig. 3 shows a defect example due to x-ray drilling processing.
4 shows the surface shape of the target board according to the present invention.
FIG. 5 is presented to show the role of the X-ray drilling and drilling processes.
6 is a view for explaining a processing method of the target board.
Fig. 7 shows the shape of the target mark.
8 shows a method for evaluating the processing accuracy of an X-ray drill processing hole.

Hereinafter, the configuration and operation of the present invention will be described in detail with reference to the accompanying drawings.

In the X-ray drilling method according to the present invention, a target board having a thickness similar to that of an actual product is prepared before the actual product is processed, the target board is processed by applying the processing conditions set for the actual product, and the result obtained by the pre- And the machining conditions for the actual product are reset by referring to the reference data.

The target board is formed by performing D / F and etching on CCL (Copper Clad Laminated) having a thickness equal to the thickness of the product obtained by hot pressing as shown in FIG. 3 to form a target mark.

The target board is not subjected to a hot press process, and the manufacturing process is completed through the formation of a dry film pattern (D / F pattern) and etching.

4 shows the surface shape of the target board according to the present invention.

Measure the size of the target board by adjusting the size of the target board or the size of the target board.

To process the product under the same condition as the actual production product, the product thickness is recognized after the hot press, and a similar thickness CCL is prepared.

When the dry film pattern (D / F pattern) and the etching process are performed on the target board in the D / F process after the CCL drying operation is completed, a target board having a target mark as shown in the center of FIG. 4 is obtained Loses.

When the target board is prepared, a guide hole is formed in the target board through an X-ray drill process.

This guide hole serves as a scale for the scale conversion of the next process according to the expansion and contraction of the product and can be used as a hole for fixing the pin for trimming and CNC drilling It is used. In the CNC drilling process, the four holes in the outer part of the PCB are recognized as cameras and processed.

FIG. 5 is presented to show the role of the X-ray drilling and drilling processes.

X-ray Drill is a device that measures two or more hole coordinate positions on a multi-layer substrate and corrects the X and Y directions by half in the coordinate position where the error with the specified drill coordinates is minimized. Here, the half-counting method is a method of drilling a position at which a position of a guide hole of a substrate and an error of a standard drill position are calculated.

X-ray Drill Mechanism Two units are mounted and machined in two axes simultaneously. High speed and high precision machining is possible. After machining, it is possible to discharge the substrate to the operator or automatically discharge to the rear of the equipment.

A certain distance movement is required to process the target board, which will be described with reference to FIG.

6 is a view for explaining a processing method of the target board.

Select one of the sample menus to process two of the menus in the menu, and enter the distance data to complete the setting.

Fig. 7 shows the shape of the target mark.

The part to be processed by the bit used in the X-ray drill with reference to the target mark of FIG. 7 and the post-processing measurement point will be described.

Referring to FIG. 7, the target marks form four concentric circles with respect to the center point. The first concentric circle 72 and the third concentric circle 76 are constituted by epoxy regions and the second concentric circle 74 and the fourth concentric circle 78 are constituted by copper regions. These first concentric circles 72 to the fourth concentric circles 74 are formed by D / F and etching.

The first concentric circle 72 is for recognizing the center point in the X-ray drilling process, and the third concentric circle 76 is for providing the error limit. The inner diameter of the third concentric circle 76 is determined in consideration of the diameter of the bit used in the X-ray drill and the error limit.

For example, when the diameter of the bit used in the X-ray Drill (unit is mm) and the tolerance limit is 20, the inner diameter of the third concentric circle 76 may be (unit: mm).

The fourth concentric circle 78 provides a baseline for the measurement for machining accuracy evaluation.

The first concentric circle 72 and the second concentric circle 74 are divided into a copper foil and an epoxy region for separating the third concentric circle 76 and the fourth concentric circle 78 (76) is set to 3.3 mm, it is possible to see whether it is processed by the upward, downward, left, and right-handing by measuring the remaining area (3.3-3.175) after processing the bit 3.175 mm.

8 shows a method for evaluating the processing accuracy of an X-ray drill processing hole.

X-ray Drill As a method of verifying the machining accuracy of the hole, it is possible to use the edge of the third concentric circle 76 left after machining the target mark as shown in FIG. 7, that is, The distance between the outline of the hole processed in the X-ray Drill Bit and the inner contour of the fourth concentric circle 78 is measured with a high magnification microscope.

Measure and manage the deviation within 20μm. This is because if an error message is generated when processing exceeds 20μm due to setting of X-ray equipment setting, it is managed separately as a defective product.

As a result of the above measurement, it is 76.40 μm - 70.01 μm = 6.39 μm, which shows a good level of processing accuracy with a deviation of about 6.4 μm.

If the measurement deviation exceeds 20 占 퐉, the processing conditions for the actual product are reset.

70 ... Target board
72 ... 1st concentric circle 74 ... 2nd concentric circle
76 ... 3rd concentric circle 78 ... 4th concentric circle

Claims (3)

delete delete A target board for confirming machining accuracy of a product obtained by a hot press,
(D / F) and etching are performed on CCL (Copper Clad Laminated) having a thickness equal to the thickness of a product obtained by hot pressing to form a target mark,
Here, the target marks include first to fourth concentric circles arranged on the basis of a center point,
Wherein the first concentric circle and the third concentric circle are constituted by an epoxy region, the second concentric circle and the fourth concentric circle are constituted by a copper region,
The first concentric circle is for recognizing the center point of the X-ray drill, and the third concentric circle is for providing an error limit, and the inner diameter of the third concentric circle is a radius of the bit used in the X- The target board being suitable for verifying the accuracy of the X-ray drill hole machining, which is determined in consideration of the diameter and the error limit.

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