JPH0678889B2 - Height measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a height geodetic device, and more particularly, to a height of a lead of a semiconductor element placed on a glass surface, that is, a floating amount of the lead from the glass surface. The present invention relates to a height measuring device for measuring.

[Conventional technology]

FIG. 5 is a perspective view showing an example of a conventional height measuring device of this type, and FIG. 6 is an operation explanatory view of the device shown in FIG.

The height measuring device shown in FIG.
Projection lens 33 for condensing 32 onto the lead 21 of the semiconductor element 20
And a light-receiving lens 34 that collects the reflected light from the lead 21,
It includes a one-dimensional sensor 35 arranged at the image forming point of the light receiving lens 34.

As shown in FIG. 6, when the height of the lead 21 changes, the reflection points of the laser light 32 on the lead 21 change to A, B, and C. The images of the reflection points A, B, C are formed by the light receiving lens 34 on the one-dimensional sensor at the positions A ', B', C ', respectively.
Therefore, the height of one lead can be obtained from the shift of the image forming point on the one-dimensional sensor 35.

[Problems to be Solved by the Invention]

In the conventional height measuring device described above, the package portion of the semiconductor element is held by suction or the like, and each lead is measured in a free state without any constraint. However, the height of each lead is important in the actual use state, that is, the state of being placed on a flat substrate, and the measurement needs to be performed in this state. If you want to measure the lead height in actual use using a conventional height measuring device, it is possible to place the semiconductor element on the glass substrate and measure it from the bottom side through the glass substrate. Since the reflected light is also imaged on the one-dimensional sensor through the light receiving lens, there is a drawback that an accurate height cannot be obtained.

[Means for Solving the Problems]

The height measuring device of the present invention comprises a laser and a lens for condensing the laser light from the laser, and a projection optical system for irradiating the laser light condensed obliquely onto the surface to be measured, and the projection device. A cylindrical lens that has a curvature in a measurement plane composed of a laser optical axis and a height measurement axis by an optical system, and condenses the reflected light of the laser light by the projection optical system from the surface to be measured. , A one-dimensional sensor arranged at an image forming point of reflected light from the measured surface condensed by the cylindrical lens, and a measurement surface arranged in front of the one-dimensional sensor near the measured surface A light-shielding plate that blocks specularly reflected light of the laser light by the light projecting optical system on parallel surfaces and allows the reflected light including diffused reflection from the surface to be measured to pass through an outer portion in a plane perpendicular to the measurement plane. Composed.

The height measuring device of the present invention comprises a laser and a lens for condensing the laser light from the laser, and a projection optical system for irradiating the laser light condensed obliquely onto the surface to be measured, and the projection device. A first cylindrical lens having a curvature in a measurement plane formed by a laser optical axis and a height measuring axis by an optical system, and condensing reflected light of the laser light by the projection optical system from a surface to be measured; A second cylindrical lens having a curvature in a plane perpendicular to the measurement plane and condensing the reflected light of the laser light from the projection optical system from the surface to be measured;
One-dimensional sensor arranged at the image forming point of the reflected light from the surface to be measured collected by the cylindrical lens, and arranged before the first and second cylindrical lenses and before the one-dimensional sensor. Is cut off the specular reflection light of the laser light by the projection optical system on a surface near the measurement surface and parallel to the measurement surface, and is perpendicular to the measurement plane of the reflected light including irregular reflection from the measurement surface. And a light-shielding plate that allows the outer portion of the plane to pass therethrough.

〔Example〕

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

FIG. 1 is a perspective view showing an embodiment of the present invention. 2 (a) and 2 (b) are operation explanatory views of the embodiment shown in FIG.

The height measuring apparatus shown in FIG. 1 comprises a laser 1 and a lens 3 for condensing the laser light 2, and a projection optical system 4 for obliquely irradiating the laser light 2 on a lead 21 which is a surface to be measured. ,
A cylindrical lens 5 that has a curvature in a measurement plane composed of a laser optical axis and a height measurement axis, and collects reflected light 12 from a lead 21 that is a surface to be measured, and a cylindrical lens 5.
The one-dimensional sensor 6 arranged at the image forming point of the reflected light 12 collected by
It is composed of a light shielding plate 7 which shields the specularly reflected light 11 on the surface of the glass substrate 25 which holds 20.

Next, the operation of this embodiment will be described with reference to FIGS. 2 (a) and 2 (b).

The laser light 2 emitted from the laser 1 can be collected by the lens 3 and is held on the glass substrate 25 by the semiconductor element 20.
The laser light 2 is specularly reflected by the surface of the glass substrate 25 at this time. Glass substrate 25
Although the laser beam 2 that has passed through is reflected on the surface of the lead 21, since the surface of the lead 21 is somewhat rough, it also causes irregular reflection. Therefore, compared with the specularly reflected light 11 on the surface of the glass substrate 25, The reflected light has a larger beam divergence angle. The cylindrical lens 5 which receives the reflected light is arranged so as to have a curvature in a measurement plane composed of the laser optical axis and the height measurement axis. Next, the cylindrical lens 5 is divided into a plane having this curvature and a plane perpendicular thereto. The operation of this embodiment will be described.

First, when considered in a plane perpendicular to the plane having the curvature shown in FIG. 2A, the cylindrical lens 5 can be considered as a simple glass plate. Therefore, the glass substrate 25
The specularly reflected light 11 on the surface and the reflected light 12 on the lead diffuse with a certain divergence angle. The specularly reflected light 11 on the glass surface is blocked by the light shield plate 7 and does not reach the one-dimensional sensor 6, but the reflected light 12 on the lead is partially shielded by the light shield plate 7 because of its wide beam divergence angle. The part of the object that spreads outside the object reaches the one-dimensional sensor 6.

Next, considering the plane having the curvature shown in FIG. 2B, the spot focused on the lead 21 by the cylindrical lens 5 is imaged on the one-dimensional sensor 6. Here, if the height of the lead 21 changes, the imaging position on the one-dimensional sensor 6 changes, and this change can be detected by the one-dimensional sensor.

As described above, due to the functions of the cylindrical lens 5 and the light shielding plate 7, the reflected light on the surface of the glass substrate 25 can be shielded and the reflected light from the lead 21 can be collected on the one-dimensional sensor 6, so that the lead height can be increased. Can be accurately measured.

FIG. 3 is a perspective view showing another embodiment of the present invention. Fourth
(A) and (b) are operation explanatory views of the embodiment shown in FIG.

The height measuring device shown in FIG. 1 comprises a laser 1 and a lens 3 for condensing the laser light 2 and is a lead which is a surface to be measured.
The projection optical system 4 for irradiating the laser beam 2 obliquely to 21 and the curvature in the measurement plane composed of the laser optical axis and the height measurement axis, and the reflected light 12 from the lead 21 which is the surface to be measured. The first cylindrical lens 5 for condensing, the second cylindrical lens 6, and the one-dimensional sensor 6 arranged at the image forming point of the reflected light 12 condensed by the first cylindrical lens 5.
A light blocking plate 7 arranged in front of the one-dimensional sensor 6 for blocking the specular reflection light 11 on the surface of the glass substrate 25 holding the semiconductor element 20; and a cylindrical lens 5 having a curvature in a plane perpendicular to the measurement plane. And a second cylindrical lens 8 arranged between the light shielding plate 7.

Next, the operation of this embodiment will be described with reference to FIGS. 4 (a) and 4 (b).

The laser light 2 emitted from the laser 1 is condensed by the lens 3 and is applied to the lead 21 input of the semiconductor element 20 held on the glass substrate 25. At this time, a part of the laser light 2 is on the glass substrate. It is specularly reflected on the surface of 25. Glass substrate 25
Although the laser beam 2 transmitted through is reflected by the surface of the lead 21, since the surface of the lead 21 is somewhat rough, diffuse reflection also occurs. Therefore, compared with the specular reflection light 11 on the surface of the glass substrate 25, The reflected light 12 has a larger beam divergence angle. First cylindrical lens 5 that receives reflected light
Has a curvature in a measurement plane composed of a laser optical axis and a height measurement axis, and the second cylindrical lens 8 is arranged so as to have a curvature in a plane perpendicular to the measurement plane. Next, the operation of this embodiment will be described by dividing it into a measurement plane and a plane perpendicular thereto.

First, when considered in a plane perpendicular to the measurement plane shown in FIG. 4A, the first cylindrical lesbian 5 can be considered as a simple glass plate. Therefore, the specularly reflected light 11 on the surface of the glass substrate 25 and the reflected light 12 on the leads respectively diffuse with a certain divergence angle, but become the convergent light by the second cylindrical lens 6. The specularly reflected light 11 on the glass surface is blocked by the light shield plate 7 and does not reach the one-dimensional sensor 6, but the reflected light 12 on the lead 21 has a wider beam divergence angle at the reflection point. Although it is partially blocked, the portion that spreads out of it reaches the one-dimensional sensor 6.

Next, when considered in the measurement plane shown in FIG. 4B, the second cylindrical lens 8 can be considered as a simple glass plate. Therefore, the spots focused on the lead 21 are imaged on the one-dimensional sensor 6 by the first cylindrical lens 5. Here, if the height of the lead 21 changes, the imaging position on the one-dimensional sensor 6 changes, and this change can be detected by the one-dimensional sensor.

As described above, by the function of the pair of cylindrical lenses 5 and 8 and the light blocking plate 7, the reflected light on the surface of the glass substrate 25 is blocked and the reflected light from the leads can be efficiently collected on the one-dimensional sensor. Therefore, the height of the lead can be accurately measured.

In the above description, the light shielding plate is described as being disposed between the second cylindrical lens and the one-dimensional sensor, but it is for shielding the reflected light on the glass surface.
There is no difference even if it is arranged between the cylindrical lens and the second cylindrical lens, or it is arranged between the first cylindrical lens and the glass plate.

〔The invention's effect〕

Since the height measuring device of the present invention can measure the height of the lead by blocking the specularly reflected light on the glass surface by the functions of the cylindrical lens and the light emitting plate, the semiconductor element mounted on the glass substrate can be used in an actual use state. The effect is that the height of the lead can be measured accurately.

The height measuring device of the present invention, by the functions of the first and second cylindrical lenses and the light blocking plate, blocks the specularly reflected light on the glass surface and efficiently collects the reflected light on the leads, thereby increasing the height of the leads. Since the height can be measured, there is an effect that the height of the lead can be accurately measured in a practical use state in which the semiconductor element is mounted on the glass substrate.

[Brief description of drawings]

1 is a perspective view of an embodiment of the present invention, and FIGS. 2 (a) and 2 (b) are views showing an optical path in a plane perpendicular to the measurement plane of the embodiment shown in FIG. 1 and an optical path in the measurement plane, respectively. FIG. 3 is a perspective view of another embodiment of the present invention,
4 (a) and 4 (b) are views showing an optical path in a plane perpendicular to the measuring plane and an optical path in the measuring plane of the embodiment shown in FIG. 3, respectively, and FIG. 5 is a conventional height measuring device. FIG. 6 is an operation explanatory view of the height measuring device shown in FIG. 1,31 …… Laser, 2,32 …… Laser light, 3 …… Lens, 5,
8 …… Cylindrical lens, 6,35 …… One-dimensional sensor,
7 ... Shading plate, 11 ... Regular reflection light on the glass surface, 12 ...
Reflected light from the lead, 20 …… Semiconductor element, 21 …… Lead,
25 …… Glass substrate.

Claims (2)

[Claims] 1. A projection optical system comprising a laser and a lens for condensing the laser beam from the laser, the projection optical system for irradiating the laser beam condensed obliquely onto the surface to be measured, and the laser by the projection optical system. A cylindrical lens that has a curvature in a measurement plane composed of an optical axis and a height measurement axis, and that collects the reflected light of the laser light from the projecting optical system from the surface to be measured, and the cylindrical lens that collects the light. The one-dimensional sensor arranged at the image forming point of the reflected light from the measured surface, and the projection on a plane parallel to the measured surface arranged immediately before the one-dimensional sensor and in the vicinity of the measured surface. A height measurement characterized by including a light-shielding plate that blocks specularly reflected light of the laser light by the optical optical system and passes through an outer portion of a reflected light including diffused reflection from the surface to be measured in a plane perpendicular to the measurement plane. apparatus. 2. A projection optical system comprising a laser and a lens for condensing the laser beam from the laser, the projection optical system for irradiating the laser beam condensed obliquely on the surface to be measured, and the laser by the projection optical system. A first cylindrical lens that has a curvature in a measurement plane composed of an optical axis and a height measurement axis, and that collects reflected light from the surface to be measured of the laser light by the projection optical system, and the measurement plane. A second cylindrical lens that has a curvature in a plane at right angles and that collects the reflected light of the laser light from the projection optical system from the surface to be measured, and the second cylindrical lens that is condensed by the first cylindrical lens. A one-dimensional sensor arranged at an image forming point of reflected light from the measurement surface, and arranged in front of the one-dimensional sensor after the first and second cylindrical lenses and in the vicinity of the surface to be measured. In front of the plane parallel to the plane And a light-shielding plate that blocks specularly reflected light of the laser light by the light projecting optical system and allows an outer portion of a reflected light including diffused reflection from the measured surface to pass through in a plane perpendicular to the measurement plane. measuring device.