JP3634053B2 - Component mounting method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a component mounting method in an electronic component mounter for inserting and mounting an electronic component on a circuit board (printed circuit board) or the like.
[0002]
[Prior art]
In electronic component mounting, as products become lighter, thinner and smaller and components become smaller, there is a need for higher precision in the positioning of electronic components when they are picked up and mounted. At the same time, improvement in productivity is also desired. Hereinafter, a conventional component mounting method will be described with reference to FIGS.
[0003]
FIG. 2A is an overview of the electronic component mounting machine.
In the figure, reference numeral 1 denotes a mounting means for sucking and mounting components. Reference numeral 2 denotes a transfer unit that carries the circuit board 6 in and out. A component supply unit 3 supplies components to the mounting means 1. A robot unit 4 moves and positions the mounting means 1. An operation panel (control unit) 5 controls the entire electronic component mounting machine and is operated by an operator. Reference numeral 6 denotes a circuit board on which components are mounted by the mounting means 1.
[0004]
FIG. 2B is a detailed view of the robot unit 4. The mounting means 1 is moved and positioned by a motor 7 and a ball screw 8. At this time, the position is detected by the linear scale 9 to perform accurate positioning.
A component mounting method in the electronic component mounter configured as described above will be described below with reference to the flowchart of FIG.
[0005]
As a first determination process, if the temperature difference from the previous mounting is equal to or less than a certain value, the mounting process from # 31 is performed (# 30). That is, the circuit board 6 is transported (# 31), the suction position is calculated (# 32), the mounting means 1 is moved to the suction position (# 33), and the mounting means 1 sucks components from the component supply unit 3 (# 34). Next, the mounting position is calculated (# 35), the mounting means 1 is moved to the mounting position (# 36), and the mounting means 1 mounts a component on the circuit board 6 (# 37). If it is not the EOP of one circuit board, the mounting is repeated (# 38), and if the production is not finished, the process is repeated from the beginning (# 39).
[0006]
By the way, in the above mounting method, not only the ball screw 8 of the robot unit 4 expands and contracts due to the temperature change at the time of component mounting, but also the linear scale 9 itself used for position detection expands and contracts. It has become. In order to prevent this, a temperature detection element is connected to the control unit 5, the installation atmosphere temperature of the electronic component mounting machine is detected, and steps # 30 and # 40 shown in FIG. 4 are provided.
[0007]
That is, if the temperature difference from the previous time is not less than a certain value (# 30), machine calibration is performed (# 40). Here, the machine calibration is to detect how much misalignment occurs when the mounting means 1 is positioned using various cameras and sensors, and store this as an offset value.
[0008]
This offset value is added when the suction position / mounting position of the mounting means 1 is calculated (# 32 / # 35), so that the movement to the suction position / mounting position is accurately and accurately positioned.
[0009]
[Problems to be solved by the invention]
This component mounting method requires high productivity as well as highly accurate positioning and mounting.
However, in the conventional component mounting method, a decrease in operation due to machine calibration is unavoidable, and in order to improve productivity, is it necessary to increase the temperature difference judgment value in # 30 and reduce the number of machine calibrations? Or, it was necessary to install an electronic component mounting machine in a temperature-controlled room. However, in the former case, the mounting accuracy is lowered, and in the latter case, there is a problem that capital investment increases.
[0010]
SUMMARY OF THE INVENTION An object of the present invention is to provide a mounting method capable of realizing high accuracy of mounting by accurate positioning and at the same time high productivity.
[0011]
[Means for Solving the Problems]
In order to solve this problem, the present invention is a component mounting method in an electronic component mounting machine having a position detecting means such as a linear scale, and uses two types of linear scales having different thermal expansion coefficients, and between the two linear scales. The component mounting method is characterized in that an offset value for positioning is calculated by detecting a difference between detection positions.
[0012]
As a result, high-precision mounting by accurate positioning and high productivity can be realized at the same time regardless of changes in the installation atmosphere temperature of the electronic component mounting machine.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
The invention according to claim 1 of the present invention, there is provided a component mounting method for performing position correction of the mounting means by the position information detected by the position detecting means according to a linear scale, the linear scale of two different coefficients of thermal expansion When using the material, each linear scale expands and contracts around the fixed origin position at the common position when expanding and contracting by heat, and both the expanded and contracted linear scales are detected at the common position detection position. The component mounting method is characterized in that a difference in detection information is calculated, an offset value of each position is calculated in proportion to the distance from the origin position from this difference, and the offset value is used for positioning of the mounting means. The invention according to claim 2 calculates an offset value for each positioning of component suction and component mounting, calculates an average of the offset values, and uses it for positioning of the mounting means. In addition, the invention according to claim 3 is an electronic component mounting method that uses two linear scales having different thermal expansion coefficients and performs position correction at the time of component adsorption and mounting of the mounting means. A step of transporting the circuit board, a step of calculating the suction position of the component, a step of moving the mounting means to the suction position, and sucking the component from the component supply unit by the mounting means, and at the same time, two kinds of linear scales at the detection position Detecting a difference between them, calculating and storing an offset value for positioning based on the difference, calculating a mounting position based on the offset value, moving the mounting means to the mounting position, and mounting means A part is mounted on the circuit board, and at the same time, the difference between the two linear scales at a predetermined detection position is detected, and an offset value for positioning based on the difference is calculated. It consists憶to step a mounting method of electronic components and performs position correction implementation means by the offset value, the installation ambient temperature of the electronic component mounting apparatus has the effect that each becomes a separate expansion amount The offset value can be accurately calculated by detecting the difference.
[0014]
In addition, by measuring the separate expansion / contraction amounts of the two types of linear scales, it is possible to perform accurate positioning without displacement due to expansion / contraction of the robot unit, and to perform mounting without reducing productivity. It becomes possible.
[0015]
Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1, 2, and 3.
(Embodiment 1)
FIG. 2 is an overview of the electronic component mounting machine, and the description in the conventional example is cited. However, in FIG. 2B, only one linear scale 9 is shown, but in this embodiment, one robot unit 4 is provided with two linear scales. This detailed description will be described later with reference to FIG.
[0016]
FIG. 1 is a flowchart of this embodiment. The present embodiment will be described with reference to FIG.
First, the circuit board 6 is conveyed (# 11), the suction position is calculated (# 12), the mounting means 1 is moved to the suction position (# 13), and the mounting means 1 sucks components from the component supply unit 3 (# 14). At this time, the linear scale is simultaneously measured, and the offset value is calculated and stored (# 20). This process will be described later with reference to FIG.
[0017]
Next, the mounting position is calculated (# 15), the mounting means 1 is moved to the mounting position (# 16), and the mounting means 1 mounts a component on the circuit board 6 (# 17). At this time, the linear scale is simultaneously measured, and the offset value is calculated and stored (# 20 '). This process will be described later with reference to FIG. If it is not the EOP of one circuit board, the mounting is repeated (# 18). If the production is not finished, the process is repeated from the beginning (# 19).
[0018]
In other words, without performing machine calibration as a separate process from the mounting process as in the conventional example, the linear scale measurement is performed in parallel at the time of suction and mounting, and the offset value is calculated and stored. Therefore, it is possible to perform mounting accurately without reducing productivity.
Here, the principle of offset value calculation in the present embodiment will be described with reference to FIG.
[0019]
As shown in FIG. 3, the robot unit 4 is provided with two linear scales (9a, 9b). Each linear scale is formed of materials having different thermal expansion coefficients. The origin position is fixed so that it does not shift during expansion and contraction due to heat. Each linear scale expands and contracts around a fixed origin when expanding and contracting by heat. Hereinafter, the description will be made focusing on the origin position and the 1000 mm position.
[0020]
FIG. 3A shows a state at the reference temperature. At the reference temperature, the 1000 mm detection position of each linear scale indicates the actual 1000 mm position.
FIG. 3B shows a state at +10 degrees C.
In this state, each linear scale exhibits a different extension. Here, the linear scale 9b has a larger thermal expansion coefficient. At this time, the 1000 mm detection position of each linear scale is a position larger than the actual 1000 mm position. Normally, the positioning of the mounting means 1 is performed based on one linear scale, but in this embodiment, the detection deviation of the detection position of the other linear scale is measured at the time of positioning. This detection deviation increases when the temperature is higher than the reference temperature, and increases in the reverse direction when the temperature is lower than the reference temperature. That is, by detecting the difference (detection deviation) in the detection position of the linear scale, it is possible to calculate an offset value for positioning at the actual accurate position.
[0021]
In addition, since the expansion and contraction of the linear scale is proportional to the distance from the origin position with the origin position as the center, it is also possible to calculate the offset value when positioning to another position from the obtained offset value. Therefore, in the linear scale measurement process (# 20, # 20 ′) in FIG. 1, the offset value for each position can be calculated by detecting the difference (detection deviation) of the linear scale at various positions each time. it can. Since the offset value is proportional to the distance from the origin position, the offset value is converted according to each position and used for positioning at each position. (# 12, # 15)
In addition, since the offset value can be calculated for each suction / mounting positioning, the average of these values can be used to measure the effects of measurement errors and linear scale detection error due to slight positioning errors. The mounting accuracy can be further improved.
[0022]
【The invention's effect】
As described above, according to the present invention, the offset value for positioning is calculated by detecting separate expansion amounts using two types of linear scales having different thermal expansion coefficients. High-precision mounting is possible, for example, accurate positioning without misalignment is possible, and at the same time, an extra step for offset calculation is not required, so that high productivity can be realized.
[Brief description of the drawings]
FIG. 1 is a flowchart showing a component mounting method according to an embodiment of the present invention.
2A is a schematic view of an electronic component mounting machine, and FIG. 2B is a detailed view of a robot unit.
3A and 3B are diagrams illustrating the principle of offset value calculation according to an embodiment of the present invention.
FIG. 4 is a flowchart showing a conventional component mounting method.
[Explanation of symbols]
# 12 Suction position calculation process # 13 Mounting means moving process # 14 Component suction process # 15 Mounting position calculating process # 16 Mounting means moving process # 17 Component mounting process # 20 Linear scale measurement process # 20 'Linear scale measurement process

Claims (3)

A component mounting method for correcting the position of mounting means based on position information detected by position detection means using a linear scale , wherein the linear scale uses two kinds of materials having different thermal expansion coefficients, and each linear scale is a thermal When expanding / contracting, it expands / contracts around the fixed origin position at the common position, detects both expanded / contracted linear scales at the detection position of the common position, calculates the difference between the detection information of both linear scales, and from this difference A component mounting method, wherein an offset value at each position is calculated in proportion to a distance from an origin position, and the offset value is used for positioning of mounting means . 2. The component mounting method according to claim 1 , wherein an offset value is calculated for each positioning of component suction and component mounting , an average of the offset values is calculated and used for positioning of the mounting means . In an electronic component mounting method that uses two types of linear scales having different thermal expansion coefficients and performs position correction at the time of component suction / mounting of the mounting means, a step of conveying a circuit board, and a step of calculating a suction position of the component , The step of moving the mounting means to the suction position, and the mounting means picks up the component from the component supply unit, simultaneously detects the difference between the two linear scales at the detection position, and calculates the offset value for positioning based on the difference A step of storing, a step of calculating the mounting position based on the offset value, a step of moving the mounting means to the mounting position, and mounting the component on the circuit board by the mounting means, and at the same time two types at predetermined detection positions The process of detecting the difference between the linear scales and calculating and storing the offset value for positioning based on the difference. Mounting method of electronic components and performs a correction.

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