JP2871116B2 - Through hole inspection equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a through hole inspection apparatus, and more particularly, to a through hole regularly formed on a green sheet in a zigzag pattern in a manufacturing process of a multilayer ceramic substrate used for a hybrid IC or the like. The present invention relates to a through-hole inspection device for inspecting holes.

[0002]

2. Description of the Related Art A conventional through-hole inspection apparatus will be described in detail with reference to the drawings. Referring to FIG. 4, which shows an example of a conventional through-hole inspection device, the through-hole inspection device includes a table moving mechanism 1 that fixes a work to be inspected on an upper surface and moves in a uniaxial direction, and a table moving mechanism 1. A table drive control unit 2 for controlling and outputting an encoder pulse a, an origin detector 3 for detecting an origin position of the table moving mechanism 1 and outputting an origin signal b, and a direction perpendicular to the moving direction of the table moving mechanism 1 A line sensor 4 provided at a scanning position, a line sensor control unit 5 for outputting an image signal c of the line sensor 4, a scanning clock d and a scanning trigger e, and an encoder pulse a output by the table drive control unit 2. An X mask signal generation circuit 6 for receiving an origin signal b output from the origin detector 3 and generating an X mask signal f; A Y-mask signal generating circuit 7 which receives a scanning clock d and a scanning trigger e output from the control unit 5 and generates a Y-mask signal g; an image signal c, a scanning clock d and an X-mask signal output from the line sensor control unit 5 It includes a defect detection unit 8 that receives an X mask signal f output from the generation circuit 6 and a Y mask signal g output from the Y mask signal generation circuit 7 and detects a defect in a through hole.

Next, a conventional through-hole inspection apparatus will be described in more detail. Here, through-holes are formed in the green sheet as a work for embedding conductors in order to be used as a multilayer ceramic substrate after lamination and firing. The line sensor 4 is fixed via the optical system 4a at a position where the inspection area of the green sheet, which is the inspection object, fixed to the upper surface of the table moving mechanism 1 can be seen. In this inspection apparatus, an image for one line is captured by the line sensor 4, then the inspection object is moved by one line by the table moving mechanism 1, and this is repeated to capture an image of the entire inspection area. Captured image signal c
Is converted into a binary image signal c 'by the binarization circuit 8a of the defect detection unit 8. The X mask generation circuit 6 divides the frequency of the encoder pulse a output from the table drive control unit 2 with the origin signal b output from the origin detector 3 as a starting point, and generates an X mask signal f.

FIG. 5 shows an operation time chart of the Y mask generation circuit 7. The Y mask generation circuit 7 divides the frequency of the scanning clock d with the scanning trigger e as a starting point,
A Y mask signal g is generated.

FIG. 6 shows a mask pattern h generated from the X mask signal f and the Y mask signal g, developed for the inspection area. The mask pattern h is a lattice pattern.

The area counter 8b of the defect detecting section 8 determines whether or not a through-hole exists in the line sensor while the binary image signal c 'is at a high level and the X mask signal f and the Y mask signal g are both at a high level. The scanning clock d output from the control unit 5 is counted and stored in a memory on the array. The comparison circuit 8c of the failure detection unit 8 compares the memory of the area counter 8b with the inspection data memory 8d on the array in which the inspection data indicating the presence / absence of through holes is prepared in advance, and detects a defective portion.

In general, in the above-described conventional through-hole inspection apparatus, as shown in the following, as the resolution is increased, the number of pseudo errors tends to increase. FIG. 7 is an explanatory diagram for explaining a problem of the optical system of the conventional through-hole inspection device shown in FIG. If the inspection area is widened with respect to the object to be inspected, the captured image is deformed at the peripheral portion due to aberration of the optical system 4a that projects the image to the licensor 4, and becomes an elliptical image in the scanning direction of the licensor. For this reason, an image appears on an adjacent mask pattern for detecting the presence / absence of a through hole, resulting in a pseudo error.

[0008]

In the above-described conventional through-hole inspection apparatus, the mask signal input to the failure detection unit is obtained by using the signals individually output from the X mask signal circuit and the Y mask signal circuit independently of each other. Since the upper mask inspected through holes formed in a zigzag pattern on the green sheet by the pattern, it was necessary to increase the resolution of the line sensor in order to obtain the same resolution from optical distortion, and to inspect the inspection data. There are disadvantages in that the storage capacity increases, the cost is high in terms of economy, and the inspection time is low.

[0009]

According to the present invention, there is provided a through-hole inspection apparatus, comprising: a table moving mechanism for fixing a work to be inspected on an upper surface and moving in a uniaxial direction; and outputting an encoder pulse by controlling the table moving mechanism. A table drive control unit, an origin detector that detects an origin position of the table moving mechanism and outputs an origin signal, and a line sensor provided at a position scanning in a direction perpendicular to the moving direction of the table moving mechanism. A line sensor control unit that outputs an image signal of the line sensor, a scanning clock and a scanning trigger, an encoder pulse output by the table drive control unit and an origin signal output by the origin detector, and an X mask signal. An X-mask signal generating circuit for generating a signal, and a scanning clock output from the line sensor control unit. A scanning mask and a scanning trigger, an X mask signal output from the X mask signal generating circuit, and a Y mask signal generating circuit for generating a Y mask signal; an image signal and a scanning clock output from the line sensor control unit; The X mask signal output by the mask signal generation circuit and the Y output by the Y mask signal generation circuit
A failure detection unit that receives a mask signal and detects a failure in the through hole.

[0010]

Next, embodiments of the present invention will be described with reference to the drawings.

Referring to FIG. 1 showing an embodiment of the present invention, this through-hole inspection apparatus includes a table moving mechanism 1 for fixing a work to be inspected on an upper surface and moving in a uniaxial direction, and a table moving mechanism 1. Control the encoder pulse a
, An origin detector 3 that detects the origin position of the table moving mechanism 1 and outputs an origin signal b, and is provided at a position where scanning is performed in a direction perpendicular to the moving direction of the table moving mechanism 1. Line sensor 4
A line sensor control unit that outputs an image signal c of the line sensor 4, a scanning clock d and a scanning trigger e, an encoder pulse a output by the table drive control unit 2, and an origin signal b output by the origin detector 3. , An X mask signal generating circuit 6 for generating an X mask signal f, a scanning clock d and a scanning trigger e output from the line sensor control unit 5, and an X mask signal f output from the X mask signal generating circuit 6 A Y mask signal generation circuit 7 for generating a Y mask signal g; an image signal c and a scanning clock d output from the line sensor control unit 5; and an X mask signal f and a Y mask signal generation output from the X mask signal generation circuit 6. A defect detection unit 8 for receiving a Y mask signal g output from the circuit 7 and detecting a defect in a through hole; That.

Here, through holes are formed in the green sheet, which is a work, for embedding conductors in order to use the green sheet after lamination and firing as a multilayer ceramic substrate. The line sensor 4 is fixed via the optical system 4a at a position where the inspection area of the green sheet, which is the inspection object, fixed to the upper surface of the table moving mechanism 1 can be seen. In this inspection apparatus, an image for one line is captured by the licensor 4, then the object to be inspected is moved by one line by the table moving mechanism 1, and this is repeated to capture an image of the entire inspection area. The fetched image signal c is converted into a binary image signal c 'by the binarization circuit 8a of the defect detection unit 8. The X mask signal generation circuit 6 divides the frequency of the encoder pulse a output by the table drive control unit 2 from the origin signal b output by the origin detector 3 to generate an X mask signal f.

FIG. 2 shows an operation time chart of the Y mask signal generation circuit 7. The Y mask signal generation circuit 7 starts the scanning trigger e, and according to the level of the X mask signal f 'of the half frequency divider obtained by dividing the X mask signal f,
A phase shift is performed, the frequency of the scanning clock d is divided, and a Y mask signal g is generated. FIG. 3 shows a mask pattern h generated from the X mask signal f and the Y mask signal g developed for the inspection area.

The mask pattern h is a staggered pattern due to the association of the X mask signal generation circuit 6 and the Y mask signal generation circuit 7 as described above. The area counter 8b of the failure detection unit 8 determines whether or not there is a through-hole by the line sensor control unit 5 while the binary image signal c 'is at a high level and the X mask signal f and the Y mask signal g are both at a high level. The output scanning clock d is counted and stored in a memory on the array. The comparison circuit 8c of the failure detection unit 8 compares the memory of the area counter 8b with the inspection data memory 8d on the array in which the inspection data indicating the presence / absence of through holes is prepared in advance, and detects a defective portion.

[0015]

As described above, according to the present invention, instead of using the signals individually output by the X mask signal circuit and the Y mask signal circuit independently of each other, the Y mask is used as the mask signal to be input to the defect detection unit. By inputting the X mask signal output from the X mask signal circuit to the signal circuit, a signal in which the X mask signal circuit and the Y mask signal circuit are associated with each other can be used as a mask signal to be input to the defect detection unit. As a result, the resolution of the line sensor can be appropriately set, the capacity for storing inspection data can be reduced, the cost can be reduced economically, and the inspection time can be shortened.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention.

FIG. 2 is a time chart showing the operation of the Y mask signal generation circuit of the embodiment.

FIG. 3 shows a mask pattern generated by the mask signal generation circuit of the embodiment.

FIG. 4 is a configuration diagram of a conventional through-hole inspection device.

FIG. 5 is a time chart showing an operation of a conventional mask signal generation circuit.

FIG. 6 shows a mask pattern generated by a conventional mask signal generation circuit.

FIG. 7 is a diagram illustrating a problem of an optical system of a conventional through-hole inspection device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Table moving mechanism 2 Table drive control part 3 Origin detector 4 Line sensor 4a Optical system 5 Line sensor control part 6 X mask signal generation circuit 7 Y mask signal generation circuit 8 Failure detection part 8a Binarization circuit 8b Area counter 8c Comparison Circuit 8d Inspection data memory a Encoder pulse b Origin signal c Image signal c 'Binary image signal d Scanning clock e Scanning trigger f X mask signal f' Half cycle X mask signal g Y mask signal h Mask pattern

Claims (1)

(57) [Claims] 1. A table moving mechanism for fixing a work to be inspected on an upper surface and moving in a uniaxial direction, a table drive control unit for controlling the table moving mechanism and outputting an encoder pulse, and an origin of the table moving mechanism. An origin detector for detecting a position and outputting an origin signal; a line sensor provided at a position for scanning in a direction perpendicular to the moving direction of the table moving mechanism; an image signal of the line sensor, a scanning clock and a scanning trigger A line sensor control section for outputting an encoder pulse output from the table drive control section and an origin signal output from the origin detector to generate an X mask signal.
A mask signal generation circuit, a Y mask signal generation circuit that receives a scanning clock and a scanning trigger output from the line sensor control unit and an X mask signal output from the X mask signal generation circuit and generates a Y mask signal; A defect for inputting an image signal and a scanning clock output by the line sensor control unit, an X mask signal output by the X mask signal generation circuit, and a Y mask signal output by the Y mask signal generation circuit, and detecting a defect in a through hole. A through-hole inspection device comprising: a detection unit.