JPH0767032B2 - Position correction method for electronic components - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to an electronic component placing apparatus for placing an electronic component having leads extending in four directions at a predetermined position on a circuit board, wherein The present invention relates to a position correction method for an electronic component that detects a correction amount for accurately mounting a component on the circuit board.

(B) Conventional technology Conventionally, the position of an electronic component for accurately mounting the electronic component on a circuit board is corrected by correcting the position of the tip of the lead of the electronic component as disclosed in Japanese Patent Laid-Open No. 60-130900. A method for recognizing by an image pickup device as a reference point for calculating a quantity
No. -117699, there is a method of recognizing the package outline of an electronic component by an image pickup device and calculating a position correction amount with reference to the package outline.

(C) Problems to be Solved by the Invention In the conventional example shown in Japanese Patent Laid-Open No. 60-130900, the correction amount is calculated with the tip of the lead of the electronic component as a reference, so that the accuracy is high when the lead is bent. It is impossible to calculate the correction amount, and in JP-A-60-117699, the packaging outline of the electronic component is used as a reference for calculating the correction amount.
There is also a problem that dimensional tolerances, burrs and the like of the outer shape of the package hinder the highly accurate calculation of the correction amount.

(D) Means for Solving the Problems The present invention has been made to solve the above problems, and an electronic component having leads extending in four directions is adsorbed and conveyed by an adsorbing means to a predetermined circuit board. An electronic device for optically recognizing the positional deviation and inclination of the electronic component in order to correct the electronic component to an appropriate position and inclination with respect to the suction means during the transportation of the electronic component placed at the position. In the component position correction method, a root portion or a tip portion of two leads, which are two reference points for calculating the positional deviation and are present on any two adjacent sides of the electronic component, and The position correction method of the electronic component is characterized in that the image pickup device recognizes the tips of the two leads existing on one arbitrary side of the electronic component, which are the two reference points for calculating the inclination. The problem Solve.

(E) Operation According to the electronic component position recognition method of the present invention, when the electronic component is sucked and conveyed by the suction means, the proper position and inclination of the electronic component with respect to the suction means are accurately calculated, and highly accurate correction is performed.

(F) Embodiments An electronic part position recognition method of the present invention will be described with reference to the drawings. FIG. 1 shows a recognition position of an electronic part, and FIG. 2 shows a configuration of an electronic part position correction method of the present invention. Figure, third
The figure is a diagram for explaining the calculation of the position correction amount.

Referring to FIG. 1, FIG. 2, and FIG. 3, the drawing numbers and configurations will be described. (1) is a flat packaging IC as an electronic component having leads extending in four directions, and (2) is the flat packaging IC. Package part, (3) lead of the flat packaging IC, (4) suction nozzle as suction means, (5) illumination, (6) TV camera as image pickup means, (7) flat package Is a proper position of the package portion of the IC, and θ is an inclination from the proper position.

Next, the position correction method for electronic parts of the present invention will be explained. As shown in FIG. 1, two reference points for calculating the inclination are a point (xa, ya) and b point (which are the tip of the lead). xb, y
b), and the two reference points for calculating the positional deviation are point c (xc, yc) and point d (xd, yd), which are the lead roots. All the reference points are recognized by the television camera (6) as the suction nozzle (4) moves in the horizontal plane as shown in FIG.

Here, the calculation method of the inclination will be described.
If the pitch between points b and b is l, then θ = sin ⁻¹ (yb−ya) / l (1) from sin θ = (yb−ya) / l. The reason for the calculation based on the y component is that when a bend occurs in the lead, the error in the y component is much smaller than the error in the x component. This is because it can be kept small.

Next, the calculation method of the positional deviation will be described. As shown in FIGS. 1 and 3, the point c is a right angle with point e (xe, ye), and l ₁ is
The distance between ce, l ₂ is the distance between de, and point o (xo, yo) is the center of the package part (2). FIG. 3 shows a comparison between the proper position (7) of the package part and the actual position of the package part (2) at point c '(xc', yc '), d'point (xd', yd '),
e'point (xe ', ye') and o'point (xo ', yo') are c
These are points corresponding to points, d points, e points, and o points, and are all general knowledge.

The coordinates of point e (xe, ye) are xe = xc + l ₁ sin θ = xd + l ₂ cos θ (2) ye = yc + l ₁ cos θ = yd−l ₂ sin θ (3) Equations (2) and (3) From l ₁ = (xd−xc + l ₂ cos θ) / sin θ = (yd−yc−l ₂ sin θ) / cos θ Therefore cos θ (xd−xc + l ₂ cos θ) = sin θ (yd−yc−l ₂ sin θ) (4) Therefore, from Eq. (4), l ₂ becomes l ₂ (cos ² θ + sin θ ² ) ＝ sin θ (yd−yc) −cos θ (xd−xc) l ₂ = sin θ (yd−yc) −cos θ (xd−xc) l ₂ Is substituted into the equations (2) and (3), xe = xd + {sinθ (yd−yc) −cosθ (xd−xc)} cosθ
(5) ye = yd- {sin θ (yd-yc) -cos θ (xd-xc)} sin θ
… (6) is obtained.

From the point e, the amount of deviation between the center o of the packaging portion (2) and the center o'point of the proper position (7) of the packaging portion, that is, the center of the suction head (4) is calculated.

The coordinates of the point e '(xe', ye ') are xe' = xc'ye '= yd' e'point (xc ', yd').

Therefore, the angle α is α = tan ⁻¹ {(xo′−xc ′) / (yo′−yd ′)} Therefore, the angle β is β = α−θ = tan ⁻¹ {(xo′−xc ′) / (yo ′ −yd ′)} −
θ.

From e ′ point (xe ′, ye ′) o ′ point (xo ′, yo ′) ▲ ▼ ＝ ▲ ▼ ＝ L The coordinates of the o point (xo, yo) are xo = xe + Lsinβ (7) yo = ye + Lcosβ (8) Equation (7) Equation (8) is substituted with Equation (5) Equation (6) and L, β. Xo, yo is obtained as follows, and the positional displacement amount between the o point and the o'point is X in the x direction and X in the y direction, respectively.
If Y Then, X and Y are obtained.

The position of the packaging IC (1) is corrected based on the data of the amount of positional deviation (X, Y) inclination θ obtained as described above.

If there is no bending of the lead, the amount of positional deviation can be calculated using the tip of the lead as a reference point. In this case, point c and point b are at the same position, and point d is point f or d The point is recognized as it is, and the recognition point is 1
The number of points can be reduced.

(G) Effect of the Invention According to the position correcting method for an electronic component of the present invention, the tip end portions of two leads existing on one arbitrary side of the electronic component, which are two reference points for calculating the tilt, are imaged by the imaging device. Since the recognition accuracy is not affected by the package and burrs of the electronic parts, and the deterioration of the recognition accuracy due to the bending of the lead is very small, accurate position correction of the electronic parts is possible and highly reliable mounting. Contribute to.

[Brief description of drawings]

FIG. 1 is a diagram showing a recognized position in position correction of an electronic component of the present invention, FIG. 2 is a configuration diagram, and FIG. 3 is a diagram explaining a method of calculating a position correction amount. (1) …… Flat packaging IC, (3) …… Lead, (4) …… Suction nozzle, (6) …… TV camera,
(7) …… The proper position of the package part.

Claims (1)

[Claims] 1. An electronic component having a lead extending in four directions is sucked and conveyed by a suction means, and the electronic component is moved to the suction means while the electronic component placed on a predetermined position of a circuit board is being conveyed. In order to correct the position shift and tilt to an appropriate position and tilt, in the position correction method of the electronic component that optically recognizes the position shift and tilt of the electronic component, the two reference points for calculating the position shift are described. Present at the root or tip of two leads respectively existing on any two adjacent sides of the electronic component and on any one side of the electronic component which is two reference points for calculating the inclination. A position correction method for an electronic component, characterized in that the tip portions of the two leads are recognized by an imaging device.