JPS63195507A - Measuring method for curvature of printed board - Google Patents

Abstract

PURPOSE:To measure a flexible material like a printed board without spoiling its quantity of deformation by structuring a detector so that both side points are contact reference terminals and one center point is a noncontact type displacement detection system. CONSTITUTION:The reference contact terminal 5 are provided to both ends of a variable length detector fitting table 2 and an optical sensor 3 is fitted at its center part. The quantity of displacement of a measurement point is detected by the sensor 3 and data is processed by using a microcomputer. At this time, while the stopper button 4 of the table 2 is pressed, a measurement span is determined. In this case, a scale shaft 6 is read and a reference terminal 7 is set to desired length on either of the right and left sides; and then both shafts 6 moves and the other is determined automatically. Then, a measurement is taken by bringing the right and left terminals 5 into contact with a target position of an output value lightly and reading the output value of the sensor 3. Therefore, the span setting time of a jig is shortened, a misread of the measured value is evaded, and the quantity of curvature is prevented from being misdetected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to measuring the amount of curvature and straightness of the surface of an object, and particularly relates to a method for measuring warpage of a printed circuit board.

[Conventional technology]

The conventional method is a span-fixed steel plate surface measuring device that has two fixed reference terminals and a movable sensor terminal located at the center of the reference terminals, as described in Japanese Patent Application Laid-open No. 59-108911. However, consideration was not given to the flexibility of the target material and its versatility in dealing with changes in size, shape, etc.

[Problem that the invention seeks to solve]

In the above conventional technology, the central sensor is a movable terminal, and there is a risk that the contact pressure during sensing may deform a flexible material to be measured, such as a printed circuit board. Furthermore, since the distance between the reference terminals is fixed, it is difficult to accommodate various sizes and shapes, and it is disadvantageous in quickly capturing the overall shape.

The purpose of the present invention is, to some extent, to enable measurement of flexible materials such as printed circuit boards without impairing the amount of deformation, and to enable easy fixing in response to changes in the shape and size of objects to be measured. The ability to change tool settings and quickly detect shapes.

[Means for solving problems]

The above purpose can be achieved by changing the structure of the detector from a three-point contact method to a contact reference terminal at two points on both sides and a non-contact displacement detection method at the center point to prevent disturbance to the object being measured. Become.

The measurement span can be changed using a sliding variable-length detector mount, and the span can be read using a scale axis attached to the top of the mount.

The method of detecting the shape of the surface to be measured is indicated by the central displacement sensor output when one end of the contact reference terminal is placed at a fixed point and the other end is expanded/contracted and rotated.

[Effect]

Adjust the contact terminals and sensor attached to the sliding variable-length adjustable detector mounting base on the surface plate in advance so that the amount of displacement is 0. Set the contact terminal interval to a certain span and place it on the object to be measured. The value indicated by the sensor when hit is the amount of displacement at the center in that span. In this case, the contact terminals on both sides are used to ensure a reference height, and there is no need to apply external force to the object to be measured, so that the warpage can be measured without deforming the object. By performing A/D conversion on the sensor output to facilitate data processing, various measurements can be performed quickly and stably. The sliding variable length detector mount allows you to set the span with one touch by pressing the stopper button, reading the desired span dimension from the scale, aligning it with the reference line, and then releasing the stopper. Therefore, it is easy to place one end at a fixed point and sequentially change the other end to the desired span length.

〔Example〕· An embodiment of the present invention will be described below with reference to FIG.

The structure of the jig is such that reference contact terminals 5 are provided at both ends of a variable-length detector mounting base 2, and an optical sensor 3 is attached to the center thereof. The amount of displacement at the measurement point is detected by a sensor, and the data is processed using a microcomputer. When measuring the warpage of the printed circuit board 1, first, the measurement span is determined while pressing the stopper button 4 of the variable length detector mounting base 2. In this case, by reading the scale axis 6 and aligning the desired length on either the left or right with the reference end 7, both scale axis 6 will move and the other will be automatically determined. When the stopper button 4 is released, the span is fixed. For measurement, the left and right contact terminals 5 are brought into light contact with the target position of measurement, and the sensor output value at that time is read. The output capture timing is determined by sending a timing signal using a foot switch or the like when the jig setting is completed. According to this embodiment, it is possible to shorten the jig span setting time, avoid reading errors in measured values, and prevent errors in the amount of warpage. It has the effect of preventing detection, etc., and can reduce man-hours by about 80% compared to conventional work methods using, for example, dial gauges.

〔Effect of the invention〕

According to the present invention, it is possible to eliminate the deformation effect on the object to be measured, which could not be avoided with conventional pressurized contact sensors.
It is now possible to directly measure the amount of warpage. Measurement accuracy is also possible up to the 10 μm level, which is sufficient performance for the warpage tolerance of printed circuit boards (minimum 0.5 mm).

The flexibility of the object to be measured can basically be addressed for all objects that remain in a fixed shape when left in space. As for measurement speed, the variable length detector mounting base allows span change time within 0.1 minute, data is outputted to the display and printer by the microcomputer, and the surface condition is graphed by performing curve tracing. be converted into

If the present invention is applied and combined with a robot arm or the like, an automatic warpage measuring station can be created.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of the present invention. 1... Printed circuit board, 2... Detector mounting base, 3...
Optical displacement sensor, 4...Stopper button, 5...Contact terminal, 6...Scale scale axis, 7...Reference end. 2C・

Claims (1)

[Claims] 1. A method for measuring warpage of a printed circuit board, characterized in that a non-contact type optical sensor is used as a displacement detector at the center, and the amount of warpage in a flexible material can be measured without changing it.