JP2770551B2 - Solder appearance inspection device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION (Industrial application field) The present invention relates to a solder appearance inspection apparatus, and more particularly to a shape of a solder in a longitudinal direction for bonding an electrode part of an electronic component to a substrate by sweeping irradiation of a laser spot light. And means for measuring

(Prior Art) Various types of means for inspecting the appearance of solder by laser light have been conventionally proposed (for example, see Japanese Patent Application Laid-Open No.
7042, 177045).

(Problems to be Solved by the Invention) Among the shapes of the solder for bonding the electronic component to the substrate, particularly important is the shape in the longitudinal direction passing through the peak position of the solder. The peak position of the solder must be quickly and accurately detected.

Therefore, an object of the present invention is to provide a solder appearance inspection apparatus for solving such a technical problem.

(Means for Solving the Problems) For this purpose, the present invention provides a laser irradiating means for sweeping and irradiating a laser spot light from above toward a solder for bonding an electrode part of an electronic component to a substrate; A light-receiving means for detecting a peak position of the solder in the transverse direction by receiving reflected light of the laser spot light swept in the transverse direction of the solder; and a solder passing through the peak position detected as described above. And a light-receiving means for detecting the height of the solder along the longitudinal direction by receiving the reflected light of the laser spot light swept and irradiated in the longitudinal direction to constitute a solder appearance inspection apparatus.

(Operation) In the above configuration, first, a laser spot light is swept in the transverse direction of the solder, and the reflected light is received by the light receiving means, thereby detecting the peak position of the solder.

Next, the laser spot light is swept and irradiated in the longitudinal direction of the solder passing through the peak position, and the reflected light is received by the light receiving means to detect the height of the solder along the longitudinal direction.

Embodiment 1 Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of a solder appearance inspection apparatus, in which 1 is a substrate on which an electronic component (hereinafter referred to as “chip”) 2 is mounted. 3 is a mold 2a of the chip 2
A number of leads 4 extending from the side to the side as electrode portions are solder for bonding the leads 3 to the substrate 1, and are generally called solder fillets.

Reference numeral 5 denotes a laser irradiating means. The laser spot light emitted from the laser irradiating means 5 is reflected by a mirror 6 and irradiates the solder 4, and the reflected light is incident on a first light receiving means 71 or a second light receiving means 72. I do. At this time, by rotating the mirror 6 in two directions, the laser beam is swept and irradiated in the XY direction. 81,8
2 is a light condensing element, and 91 and 92 are light receiving elements such as PSD.

The first light receiving means 71 is located obliquely above the solder 4 in the direction in which the solder 4 extends (the Y direction perpendicular to the tip end surface of the lead 3), and is irradiated with the laser spot light swept in the transverse direction (X direction) of the solder 4. , The peak position of the solder 4 in the transverse direction is detected. Also, the second light receiving means 72
Is to receive the reflected light of the laser spot light that is swept and irradiated in the longitudinal direction (Y direction) of the solder 4 that is obliquely above the side of the solder 4 and passes through the peak position detected as described above. Thus, the height of the solder 4 along the longitudinal direction is detected. Reference numeral 10 denotes a land of the circuit pattern formed on the substrate 1, and Q denotes a position reference mark formed at an appropriate position on the substrate 1, and the coordinate position of each land 10 with respect to the mark Q is known.

The present apparatus is configured as described above. Next, a method for inspecting the appearance of solder will be described.

2 and 3, first, a start point A is set on the side of the solder 4, from which the laser spot light is swept and irradiated in the X direction in which the lead 3 is placed, and the reflected light is transmitted to the first light receiving element. The light is received at 91 and the peak position B of the lead 3 in the transverse direction is detected. The start point A is set on the side of each land 10 which is a known position with respect to the position reference mark Q of the substrate 1 as described above.

In FIG. 3, the lead 3 is displaced upward with respect to the land 10 due to a mounting error when the electronic component 2 is mounted on the substrate 1. Further, as shown in FIG. 5, the solder 4 swells toward the right side. Therefore, the center line N1 of the lead 3 and the vertical line N2 passing through the peak position B of the solder 4 are displaced by a distance e.

Next, as shown in FIG. 4, the laser spot light is swept and irradiated along the longitudinal direction passing through the peak position B, that is, along the longitudinal line N2, and the reflected light is received by the light receiving element 92 of the second light receiving means 72. Then, the height of the solder 4 along the vertical line N2 is detected. In FIG. 4, n is a line connecting the light receiving points of the light receiving elements 92. From this line n, the quality of the shape of the solder 4 in the longitudinal direction is determined.

As described above, according to this means, the peak position B of the solder 4
Since the shape along the longitudinal direction passing through can be detected, the solder 4
The quality of the shape can be accurately determined.

In FIG. 3, it is conceivable to judge the shape of the solder fillet 4 by irradiating a laser spot light along the center line N1 of the lead 3, but this line N1 passes through the peak position B. Longitudinal line N2
Therefore, if the height is detected along the line N1, even if the shape of the solder 4 is good, it may be erroneously determined that the solder 4 is defective. It is desirable to inspect along the vertical line N2.

Embodiment 2 FIG. 6 shows another method for detecting the peak position B of the solder 4. As described above, when the laser spot light is irradiated in the X direction and the reflected light is received by the light receiving element 91, the cross-sectional shape of the solder 4 is a mountain shape having the peak position B as an apex. At the position B, most of the laser spot light is reflected toward the light receiving element 92, but at points C and D on the slope away from the peak position B, a considerable portion of the laser spot light is: Since the light is reflected sideways as indicated by the broken arrow, only a part of the reflected light enters the light receiving element 91. In other words, the reflected light of the laser spot light is most strongly reflected toward the light receiving element 91 at the peak position B. Therefore, the peak position B can be detected by detecting the point where the strongest reflected light is incident on the light receiving element 91. Then, when the peak position B is detected, the laser spot light is irradiated in the longitudinal direction as in the above case, and the height along the longitudinal direction is detected. The light receiving element 91 is not limited to the PSD, but may be any device that can determine the intensity of light, such as a photo sensor.

(Effects of the Invention) As described above, according to the present invention, by detecting the peak position of the solder and then irradiating the laser spot light in the longitudinal direction passing through the peak position, the solder along the longitudinal direction is formed. Since the shape is measured, the quality of the shape of the solder can be accurately determined.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of the present invention. FIG. 1 is a perspective view of an appearance inspection apparatus, and FIG. 2, FIG. 3, and FIG. FIG. 5, a plan view, a perspective view, FIG. 5 is a partial front view, and FIG. 6 is a plan view of a main part of another embodiment. DESCRIPTION OF SYMBOLS 1 ... Board 2 ... Electronic component 3 ... Electrode part 4 ... Solder 5 ... Laser irradiation means 71, 72 ... Light receiving means

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01B 11/00-11/30 G01N 21/84-21/91 H05K 3/34

Claims (1)

(57) [Claims] 1. A laser irradiating means for sweeping and irradiating a laser spot light from above toward solder for bonding an electrode part of an electronic component to a substrate; A light receiving means for detecting the peak position of the solder in the transverse direction by receiving the reflected light of the spot light; and a laser spot light swept and irradiated in the longitudinal direction of the solder passing through the peak position detected as described above. A light receiving means for detecting the height of the solder along the longitudinal direction by receiving the reflected light of the solder.