JP3211385B2 - Cream solder printing inspection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cream solder printing inspection method, particularly in the mounting field, after printing cream solder on a circuit board and before mounting components.

[0002]

2. Description of the Related Art Conventionally, a printing inspection method for cream solder is carried out as follows. As shown in FIG. 6A, a window 19 is set so as to include the cream solder outline 17 for the color image taken. As shown in FIG. 6B, the color of the cream solder 17 in the window 19 is extracted,
The area value and the position are detected by using the cream solder 17a as one pattern (a binary pattern detected by color extraction).
The cream solder 17 is determined by comparing the detected area value with the reference area value, and comparing the detected position with the reference position.
Was determined.

[0003]

However, FIG.
As shown in (a), depending on the printing state of the cream solder on the circuit board electrode part 28, the cream solder formed on the circuit board electrode part 28 is partially blurred and 27b and 27c
In the case where the window 2 is separated as shown in FIG.
The cream solders 27c and 27d in the 9 are color-extracted, and the extracted cream solders 27a and 27b are used as one pattern to detect the area value and the position. The quality of the cream solder was determined by comparing the detected area value with the reference area value, and comparing the detected position with the reference position, and the non-defective cream solder was determined to be defective.

An object of the present invention is to provide a cream solder printing inspection method which can correctly determine the position and area even when the cream solder is partially blurred and separated depending on the printing state.

[0005]

Means for Solving the Problems To achieve this object, a cream solder printing inspection method according to the present invention comprises the following steps. (1) Means 1 is for cream solder printed on a circuit board by color image processing using an imaging device. When performing print inspection, the process of setting a window on the cream solder for the captured image and the extraction of the color of the cream solder in the window are performed, and all cream solder patterns having an area equal to or larger than a predetermined value are detected. The process of
A step of calculating a position from the sum of the center of gravity of each cream solder pattern according to the area ratio of the detected cream solder pattern, and comparing the calculated position with a reference position to determine the quality of the cream solder. It has a process.

(2) means 2 for setting a window in the cream solder for the picked-up image when performing a print inspection of the cream solder printed on the circuit board by color image processing using an imaging device; performs cream solder color extraction in the window, calculates a step of detecting all of the cream solder pattern having a predetermined value or more of the area preset, cream solder area than the sum of all of the cream solder pattern the detected comprising steps a, and determining the quality of the cream solder by performing the <br/> calculated whether the comparison determination cream solder area value is an area within a predetermined tolerance with respect to the reference of the cream solder area value It is a thing.

(3) The means 3 includes the means 1 and the means 2. (4) A step of setting a window in a circuit board electrode portion (hereinafter referred to as a land) when performing a print inspection of cream solder printed on a circuit board by color image processing using an imaging device. Detecting the color of the lands in the window and detecting all land patterns; detecting all pseudo cream solder patterns having an area equal to or larger than a predetermined value from the detected land patterns; A step of detecting the position from the sum of the center of gravity of each pseudo cream solder pattern according to the area ratio of each pseudo cream solder pattern thus determined, and determining the quality of the cream solder by comparing the calculated position with a reference position It is provided with the step of performing.

(5) The means 5 includes a step of setting a window on a land and a step of setting a window in a land when performing a print inspection of cream solder printed on a circuit board by color image processing using an imaging device. Perform color extraction,
And detecting all of the land pattern, the area sum of all pseudo <br/> similar cream solder pattern and detecting any pseudo cream solder pattern, detected with an area larger than a predetermined value than the detected land pattern A step of calculating a cream solder area value, and whether the calculated cream solder area value is within an allowable area value with respect to a reference cream solder area value.
Determining whether the cream solder is good or not by performing a comparison determination as to whether the cream solder is good or not.

(6) The means 6 includes the means 4 and the means 5 described above.

[0010]

With this configuration, the position and area can be correctly determined even when the cream solder is partially blurred due to the printing state and the cream solder is separated.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for inspecting cream solder printing according to an embodiment of the present invention will be described below with reference to the drawings.

(Embodiment 1) The flowchart of FIG. 2 will be described with reference to FIGS. In FIG. 1, FIG. 2, and FIG. 4, the reference value (Sk) and the position reference value (Xk, Yk) of the individual area of the cream solder are previously stored in the image recognition device 4.
And set it in memory. Also, the area (SL) determined as a noise pattern, the allowable displacement (DX, DY), and the allowable area value (D
S), individual external size of cream solder (Wx, W
y), the window allowable value (Cw) is also input to the image recognition device 4 and set in the memory.

As shown in FIG. 1, the image pickup section 3 picks up an image of the circuit board 1 on which the cream solder 2 is printed (step 1).
As shown in FIG. 4A, the captured color image is
The window 9 is set on the cream solder 7. However,
The size of the window 9 is the size obtained by adding the window allowable value (Cw) to the individual outer size (Wx, Wy) of the cream solder 7, and the center position of the window 9 is
(Xk, Yk) (step 2). As shown in FIG. 4B, the color of the cream solder 7 is extracted by the color recognition in the window 9, and all the cream solder patterns (PC1, PC2,...) Having an area equal to or larger than a predetermined value (SL) are set. .. PCn) is detected (step 3). As shown below, the position is calculated from the sum of the barycentric positions of the respective patterns according to the detected cream solder pattern area ratio by the determination formula shown in (Equation 1) (step 4).

[0014]

(Equation 1)

Based on the calculated position (X, Y), the reference position (Xk, Yk) set in the memory in advance, and the positional deviation allowable value (DX, DY), a positional deviation is determined by the following expression. .

If the judgment formula Xk> X + DX or Xk <X-DX or the judgment formula Yk> Y + DY or Yk <Y-DY is satisfied, it is judged as NG, and if it is desired, the judgment is OK.
Is determined (step 5). Also, the detected area (S)
And the area reference value (Sk) and the allowable area value (DS) set in the memory in advance, the area is determined by the following determination.

If Sk> S + DS or Sk <S-DS is satisfied, it is determined as NG, and if not, OK is determined.
Is determined (step 6). If it is determined as NG in step 5 or 6, the cream solder is determined to be defective (step 7).

In FIG. 1, reference numeral 5 denotes a keyboard, and 6 denotes a cathode ray tube (CRT) as a display.

(Embodiment 2) The flowchart of FIG. 3 will be described with reference to FIGS. 1, 3 and 5, a reference value (Sk) and a position reference value (Xk, Yk) of the individual area of the cream solder 7 are input to the image recognition device 4 and set in the memory in advance. Also, the area (SL) determined as a noise pattern, the allowable displacement (DX, DY), and the allowable area value (D
S), the outer size (Wx, Wy) of the individual circuit board electrode portion (hereinafter referred to as land), and the window allowable value (Cw) are also input to the image recognition device 4 and set in the memory.

As shown in FIG. 1, the image pickup section 3 picks up an image of the circuit board 1 on which the cream solder 2 is printed on the lands 8 (step 1). As shown in FIG. 5A, a window 9 is set on a land 8 for a captured color image. However, the window 9 is the outer size of the individual land 8, and the position of the window 9 is the outer shape of the land 8 itself (step 2). As shown in FIGS. 5B and 5C, the color of the land 8 is extracted by the color recognition in the window 9,
All binarized land patterns (PL1, PL2
..) Are detected (step 3). As shown in FIG. 5D, the detected land pattern is inverted between black and white to detect a pseudo cream solder pattern (PC1, PC2,... PCn) (step 4). As shown below, the position is detected from the sum of the positions of the centers of gravity of the respective pseudo cream solder patterns according to the detected area ratio of the pseudo cream solder pattern by the determination formula shown in (Equation 1) (step 5).

Based on the detected position (X, Y), the reference position (Xk, Yk) set in the memory in advance, and the positional deviation allowable value (DX, DY), the positional deviation is determined by the following expression. .

If Xk> X + DX or Xk <X-DX or Yk> Y + DY or Yk <Y-DY holds, it is judged as NG, and if it does not hold, it is OK.
Is determined (step 6).

Further, the detected area (S), the area reference value (Sk), and the area allowable value (DS) preset in the memory are determined by the following determination formula.

If SK> S + DS or Sk <S-DS is satisfied, it is determined as NG. If not, OK is determined.
Is determined (step 7). If it is determined as NG in step 6 or step 7, the cream solder is determined to be defective (step 8).

[0025]

As is apparent from the above description of the embodiment, according to the cream solder printing inspection method of the present invention, even if the cream solder is partially blurred depending on the printing state and the cream solder is separated, the position and area are also determined. Is determined correctly.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing the configuration of an apparatus used in a cream solder print inspection method according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a cream solder printing inspection method according to the first embodiment.

FIG. 3 is a flowchart illustrating a cream solder print inspection method according to the second embodiment.

FIG. 4 is a schematic view of a cream solder printing pattern corresponding to FIG. 2;

FIG. 5 is a schematic view of a cream solder printing pattern corresponding to FIG. 3;

FIG. 6 is a schematic diagram illustrating a state in which a part of the cream solder is not separated due to blurring in the conventional cream solder printing inspection method.

FIG. 7 is a schematic view illustrating a state in which a part of the cream solder is slightly separated.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Circuit board 2, 7 Cream solder 3 Imaging part 4 Image recognition device 8 Circuit board electrode part 9 Window

Continuation of the front page (56) References JP-A-3-257354 (JP, A) JP-A-61-293659 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 21 / 84-21/958

Claims (6)

(57) [Claims] 1. A step of setting a window in a cream solder for a captured image when performing a print inspection of cream solder printed on a circuit board by color image processing using an imaging device; And extracting all the cream solder patterns having an area equal to or larger than a predetermined value, and extracting the cream from the sum of the positions of the centers of gravity of the cream solder patterns according to the area ratio of the detected cream solder patterns. A cream solder printing inspection method, comprising: a step of calculating a solder position; and a step of comparing the calculated cream solder position with a reference cream solder position to determine the quality of the cream solder. 2. A case of performing the printing inspection of solder cream is printed on the circuit board by the color image processing using an imaging device, and setting the window to the cream solder on the image captured, cream in the window A step of performing solder color extraction and detecting all cream solder patterns having an area equal to or larger than a predetermined value set in advance,
Calculating a cream solder area than the sum of all of the cream solder pattern the detected surface against cream solder area value of the cream solder area value the calculated reference
Determining whether the cream solder is good or not by performing a comparison determination as to whether the solder paste is within a product allowable value . 3. A step of setting a window in a cream solder for a captured image when performing a print inspection of cream solder printed on a circuit board by color image processing using an imaging device; And extracting all cream solder patterns having an area equal to or larger than a predetermined value, and extracting the cream solder from the sum of the center of gravity of each cream solder pattern according to the area ratio of the detected cream solder patterns. Calculating the position of the cream solder, determining the quality of the cream solder by comparing and determining the calculated position of the cream solder with the position of the reference cream solder, and cream based on the area sum of the detected cream solder pattern. The step of calculating the solder area, and calculating the calculated cream solder area value and the reference cream solder area value. A step of judging the quality of the cream solder by performing a comparison judgment. 4. A step of setting a window in a circuit board electrode section when performing a print inspection of cream solder printed on a circuit board by color image processing using an imaging device, and a step of setting a circuit board electrode section in the window. Perform color extraction,
A step of detecting patterns of all circuit board electrode portions, a step of detecting all pseudo cream solder patterns having an area equal to or larger than a predetermined value based on the detected pattern of circuit board electrode portions, A step of calculating the position of the cream solder from the sum of the positions of the centers of gravity of the pseudo cream solder patterns according to the area ratio of the cream solder pattern, and performing a comparison judgment between the calculated position of the cream solder and a reference cream solder position Solder cream printing inspection method, comprising: 5. A step of setting a window in a circuit board electrode portion when performing a print inspection of cream solder printed on a circuit board by color image processing using an image pickup device, and a circuit board electrode portion in the window. Detecting the cream solder patterns of all the circuit board electrode portions, and detecting all pseudo cream solder patterns having an area equal to or larger than a predetermined value from the detected cream solder patterns of the circuit board electrode portions. a step, total and the detected
Area tolerance calculating a cream solder area value than the area sum of the pseudo cream solder pattern for cream solder area value of the cream solder area value the calculated criteria Te
Determining whether the cream solder is good or not by performing a comparison determination as to whether or not the solder paste is within the cream solder print inspection method. 6. A step of setting a window in a circuit board electrode portion with respect to a captured image when performing a print inspection of cream solder printed on a circuit board by color image processing using an imaging device; Extracting the color of the circuit board electrode portion and detecting the pattern of all the circuit board electrode portions, and extracting all the pseudo cream solder patterns having an area equal to or larger than a predetermined value from the detected pattern of the circuit board electrode portion. A step of calculating the position of the cream solder from the sum of the positions of the centers of gravity of the respective pseudo cream solder patterns according to the area ratio, and performing a comparison judgment between the calculated position of the cream solder and the position of the reference cream solder to determine A step of judging pass / fail, a step of calculating a cream solder area value from the sum of the areas of the detected pseudo cream solder patterns, Determining the quality of the cream solder by comparing and determining the output cream solder area with a reference cream solder area.