CN114354498B - Design method of light source for welding spot detection and welding spot detection device - Google Patents
Design method of light source for welding spot detection and welding spot detection device Download PDFInfo
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Abstract
The application provides a design method of a light source for welding spot detection and a welding spot detection device, which relate to the technical field of welding spot detection and comprise the steps of providing a hemispherical lampshade, wherein a plurality of lamp beads are annularly distributed on the inner wall of the lampshade; calculating an included angle between the fixing surface of the lampshade where the light source is positioned and the horizontal plane through the reference height of the reference light source, the working distance between the reference light source and the target welding point, the included angle between the fixing surface of the lampshade where the reference light source is positioned and the horizontal plane, and the working distance between the light source and the target welding point; and respectively determining the setting parameters of each lamp bead on the inner wall of the lamp shade according to the included angle between the fixed surface of the lamp shade where the light source is located and the horizontal plane, and obtaining the required light source. According to the design method of the light source for detecting the welding spots, the relation between the reference light source and the light source is utilized, the design parameters of the light source are directly and accurately calculated through the known parameters of the reference light source, the result is accurate, the efficiency is high, the period of light source design is effectively improved, and the accuracy of the detection result is improved.
Description
Technical Field
The application relates to the technical field of welding spot detection, in particular to a design method of a light source for welding spot detection and a welding spot detection device.
Background
Integrated circuits have been embedded in our lives as the core of products of the electronic age. The integrated circuit is composed of the most basic resistor, capacitor and the like, and can be applied to various electronic products with various functions, such as household appliances like televisions, computers, mobile phones and the like. The problem facing the production of a large number of electronic products is the detection of the pads of the integrated circuit, which depends on machine vision imaging, and how to perform accurate detection with low cost. The integrated circuit of ordinary panel trade possesses hundreds of solder joints usually on, and most solder joints are concentrated on about 3mm, and machine vision detects the inevitable development achievement that the condition of examining is missed, promotion detection efficiency that avoids the naked eye to detect. However, in visual inspection, the design of the light source directly determines the detection rate.
A light source specially used for detecting soldering tin in the industry is also called an AOI light source, and has different standard AOI light sources according to the production characteristics of different manufacturers, but when the light source is actually applied to different projects, the limitation of factors such as the position of a field machine, the size of a product and the like possibly exists, so that the standard AOI light source is not suitable for a current scene; the existing new light source design steps are various, and the design period of the new light source is prolonged by a method of trial and error elimination of experience parameters, so that the whole project schedule is delayed, and the design error is large, so that the detection result is not accurate.
Disclosure of Invention
An object of the embodiments of the present application is to provide a method for designing a light source for detecting a solder joint and a solder joint detecting apparatus, which can directly obtain design parameters of the light source through calculation according to parameters of an existing reference light source and parameters between the reference light source and the light source, thereby effectively improving a period of designing the light source and improving accuracy of a detection result.
In one aspect of the embodiment of the application, a design method of a light source for welding spot detection is provided, which is used for welding spot detection of a circuit board with multiple welding spots, and comprises the steps of providing a hemispherical lampshade, and annularly distributing a plurality of lamp beads on the inner wall of the lampshade; calculating an included angle between the fixing surface of the lampshade where the light source is positioned and the horizontal plane through the reference height of the reference light source, the working distance between the reference light source and the target welding point, the included angle between the fixing surface of the lampshade where the reference light source is positioned and the horizontal plane, and the working distance between the light source and the target welding point; and respectively determining the setting parameters of each lamp bead on the inner wall of the lampshade according to the included angle between the fixed surface of the lampshade where the light source is positioned and the horizontal plane, and obtaining the required light source.
Optionally, calculating an included angle between the fixing surface of the lampshade where the light source is located and the horizontal plane by using the reference height of the reference light source, the working distance between the reference light source and the target welding point, the included angle between the fixing surface of the lampshade where the reference light source is located and the horizontal plane, and the working distance between the light source and the target welding point includes: the setting parameters of the lamp beads on the lamp shade satisfy the relational expression: alpha is alpha1=90°-arctan((x+y1) (tan (90 ° - α))/(x + y)) (1); wherein x is the reference height of the reference light source, y is the working distance between the reference light source and the target welding point, and alpha is the included angle between the fixed surface of the lampshade where the reference light source is located and the horizontal plane; y is1Is the working distance, alpha, between the light source and the target weld1The included angle between the fixed surface of the lampshade where the light source is positioned and the horizontal plane.
Optionally, the setting parameters of the lamp bead on the lamp shade satisfy the relational expression: alpha is alpha1=90°-arctan((x+y1) (tan (90 ° - α))/(x + y)) includes: according to the fixed surface of the lamp bead on the lampshade and the light emitting side of the lamp beadEstablishing a right-angled triangle calculation model for a target plane where a target welding point is located; the included angle between the fixed surface and the light emitting direction of the lamp bead is a right angle, the included angle between the fixed surface and the target plane is equal to the included angle alpha between the fixed surface and the horizontal plane, the sum of the included angle beta between the light emitting direction of the lamp bead and the target plane and the included angle alpha between the fixed surface and the horizontal plane is equal to 90 degrees, and the distance formed by the perpendicular line of the target plane passing through the right angle is the sum of x and y; an included angle beta between the light emitting direction of the lamp bead and a target plane satisfies a relational expression, and z = (x + y)/tan beta (2); wherein x and z are known and constant values, and z is the dimension of a right-angle side of the target plane corresponding to tan beta; obtaining the working distance y of the current lamp bead1Substituting the numerical value of (2) into the relational expression (2), and calculating to obtain the included angle beta1(ii) a According to beta1=90°-α1The relational expression (1) was obtained.
Optionally, the setting parameters of the lamp bead on the lamp shade satisfy the relational expression: alpha is alpha1=90°-arctan((x+y1) (tan (90 °)/(x + y)), the method further comprising: and determining the diameter of the light emitting surface of the light source of the lampshade.
Optionally, the determining the diameter of the light emitting surface of the light source of the lamp shade comprises: confirming a detection visual field required by a light source according to the target welding spot; and determining the diameter of the light emitting surface of the light source according to the detection visual field, wherein the detection visual field is more than or equal to one half of the diameter of the light emitting surface of the light source.
Optionally, after determining the diameter of the light emitting surface of the light source of the lampshade, the method further comprises: when the diameter of the light emitting surface of the light source is changed, establishing a light emitting surface diameter relational expression of the light source, wherein the relation satisfies that delta r =deltay/(tan (90-alpha)) (3); Δ r is the difference between the source radius and the reference source radius, and Δ y is the working distance that needs to be increased.
Optionally, when the diameter of the luminous surface of the light source is changed, establishing a luminous surface diameter relation of the light source, wherein Δ r = ^ Δ y/(tan (90 ° - α)) comprises: the model is calculated according to the right triangle, and the following results are obtained: z is a radical of1=△r +z（4）； y1= y +. DELTA.y (5); wherein z is the dimension of one of the legs of the target plane corresponding to tan β, y1Is the working distance of the light source; substituting the above relational expressions (4) and (5) into the relational expression (2)) And the relation (3) can be obtained according to the constant value of the included angle beta.
Optionally, provide the lamp shade of hemisphere, a plurality of lamp pearls of ring distribution include on the inner wall of lamp shade: divide into at least three light source group with a plurality of lamp pearls, at least three light source group is along the highly range upon range of setting of lamp shade, and the luminous colour of the lamp pearl of the same group light source group is the same.
Optionally, the plurality of light source groups include three, are red light source group, green light source group, blue light source group respectively in proper order along the high range upon range of direction of lamp shade, and red light source group is close to the top of lamp shade.
In another aspect of the embodiments of the present application, a solder joint detection apparatus is provided, which includes a light source designed by the above design method for a solder joint detection light source, and a receiver disposed on a light path, wherein a light beam emitted from the light source irradiates a target solder joint on a multi-solder-joint circuit board, and the receiver receives a light beam reflected by the target solder joint.
The design method of the light source for detecting the welding spots and the welding spot detection device provided by the embodiment of the application comprise the steps of providing a hemispherical lampshade, and annularly distributing a plurality of lamp beads on the inner wall of the lampshade; calculating an included angle between the fixing surface of the lampshade where the light source is positioned and the horizontal plane through the reference height of the reference light source, the working distance between the reference light source and the target welding point, the included angle between the fixing surface of the lampshade where the reference light source is positioned and the horizontal plane, and the working distance between the light source and the target welding point; and respectively determining the setting parameters of each lamp bead on the inner wall of the lamp shade according to the included angle between the fixed surface of the lamp shade where the light source is located and the horizontal plane, and obtaining the required light source. According to the design method of the light source for detecting the welding spots, the relation between the reference light source and the light source is utilized, the design parameters of the light source are directly and accurately calculated through the known parameters of the reference light source, the result is accurate, the efficiency is high, the period of light source design is effectively improved, and the accuracy of the detection result is improved.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and that those skilled in the art can also obtain other related drawings based on the drawings without inventive efforts.
FIG. 1 is a flow chart of a method for designing a light source for solder joint inspection according to an embodiment of the present disclosure;
FIG. 2 is a schematic diagram of a standard AOI light source;
FIG. 3 is a schematic diagram of a standard solder joint configuration;
fig. 4 is a schematic view of a light source structure provided in this embodiment;
FIG. 5 is a triangle model created by a schematic diagram of a light source structure according to this embodiment;
FIG. 6 is a diagram showing the relationship between the diameter of the light emitting surface of the light source and the field of view provided by the present embodiment;
FIG. 7 is a comparison diagram of a triangle model of a reference light source and a light source provided in the first embodiment;
FIG. 8 is a comparison diagram of the triangle model of the reference light source and the light source provided in the second embodiment;
fig. 9 is a schematic diagram of a detection apparatus for detecting solder joints according to the present embodiment.
Icon: 100-a light source; 101-a lampshade; 102-lamp beads; 200-target welding spot; 300-receiver.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.
In the description of the present application, it should be noted that the terms "inside", "outside", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships that the products of the application usually place when using, and are only used for convenience in describing the present application and simplifying the description, but do not indicate or imply that the devices or elements that are referred to must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.
It should also be noted that, unless expressly stated or limited otherwise, the terms "disposed" and "connected" are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrally connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.
The embodiment of the application provides a design method of a light source for welding spot detection aiming at the limitation of different practical scenes, and the design method is a design mode of a non-standard AOI light source.
Specifically, referring to fig. 2, the standard AOI light source is composed of three ring lights with different colors, different angles, and different diameters of the light emitting surface, wherein the colors of the ring lights are three primary colors: red, green, blue; since standard solder joints are mostly sloped or pyramidal (as shown in fig. 3), different colors present different slope information when illuminated at different angles to the solder joint.
The welding spots on the PCB are shot by a combined plane of an industrial camera lens and an AOI light source, wherein each welding spot presents different colors due to different gradients and is respectively red, green and blue from top to bottom, and whether the welding spot is qualified or not is judged according to the hue and the saturation.
The unsaturated spots (defective spots) differ in color appearance: the hole defect appears black on the welding spot, the defect with less tin has only red information, and the defect without green and blue indicates that only the welding spot has a plane and basically has no gradient.
The standard AOI light source on the market works at a distance of 25 mm. Because the PCBs in various industries are different, the front surface of the common PCB is provided with plug-in components with different heights, and the back surface to be detected is provided with a veneering component with the height difference within 5 mm, when the PCB is detected, if the working distance is not limited, the standard AOI light source can be directly selected. Some industries have PCB detection surfaces with plug-ins, the height can reach 40 mm, 60 mm, even 70 mm, and at this time, if the light source is used for debugging to achieve the same effect, the detection efficiency is reduced by half because parameters such as exposure, gain and the like need to be changed.
If the detection efficiency is considered, the image effect difference is obvious; generally, the welding spot is full when the working distance of the light source is 25 mm, the color of the welding spot is not full when the working distance of the light source is 55 mm, most of blue color appears black due to improper angle of the light source, and the OK welding spot is easily judged as the NG welding spot with the black hole in the state.
Therefore, according to the above situation, when the embodiment of the present application considers the detection efficiency, a new light source (hereinafter, collectively referred to as a required light source or a light source) can be designed based on the situation of the reference light source (i.e., the standard AOI light source); and calculating the required light source related parameters according to the parameters such as the angle of the reference light source, the diameter of the light emitting surface and the like.
Referring to fig. 1, an embodiment of the present application provides a method for designing a light source for solder joint inspection, which confirms design parameters of a desired light source 100 through a relationship between a reference light source and the desired light source 100 on the premise of knowing the design parameters of the reference light source, so as to obtain the desired light source 100; specifically, the method comprises the following steps:
s100: a hemispherical lampshade 101 is provided, and a plurality of lamp beads 102 are annularly distributed on the inner wall of the lampshade 101.
The lampshade 101 is of a hemispherical shape, and a through hole is formed in the top of the lampshade 101, so that a light beam emitted by the lamp bead 102 to the target welding point 200 is reflected to the receiver 300 through the through hole and is received by the receiver 300.
Be provided with a plurality of lamp pearls 102 on the inner wall of lamp shade 101, lamp pearl 102 is LED lamp pearl 102, divides a plurality of lamp pearls 102 into at least three light source group, and at least three light source group is along the highly range upon range of setting of lamp shade 101, and the luminous colour of the lamp pearl 102 of the light source group of the same group is the same.
Illustratively, as shown in fig. 4, along the annular direction of the lamp shade 101, the plurality of lamp beads 102 are divided into three groups according to the height direction of the lamp shade 101, each group of lamp beads 102 is of the same color, and the three groups of lamp beads are respectively a red light source group (red lamp bead group), a green light source group (green lamp bead group), and a blue light source group (blue lamp bead group) in turn along the height stacking direction of the lamp shade 101, and the red light source group is close to the top of the lamp shade 101. The same group of beads 102 are located on the same fixing surface of the lampshade 101, in other words, the hemispherical lampshade 101 is not strictly hemispherical, the outer surface of the lampshade 101 is composed of three groups of fixing surfaces (planes), and two adjacent fixing surfaces between the three groups of fixing surfaces are spaced by a certain distance, so that the outer surface of the lampshade 101 forms an approximate hemispherical shape.
Taking one group of the lamp beads 102 as an example, the left edge of the triangle is a fixing surface of the group of the lamp beads 102, the group of the lamp beads 102 is defaulted to be vertical to the fixing surface, the right edge of the triangle is a simulated emission light of the lamp beads 102, the right edge of the triangle is defaulted to be parallel to the lamp beads 102, the point at the lower right corner of the triangle is a measured object point, and the lower edge of the triangle is a target plane, namely the surface of the measured object (a circuit board with multiple welding spots), namely a horizontal plane; the parameter α is an angle between a fixing surface of the set of beads 102 and a horizontal plane, x is a height of the set of beads 102 with respect to a bottom plane of the lamp casing 101 (i.e., a height between a setting plane where the set of beads 102 is located and the bottom plane of the lamp casing 101), y is a working distance of the light source when the test image effect is optimal, and the rest are auxiliary parameters, and a triangular model (as shown in fig. 5) is established through the parameters to calculate required parameters.
In addition, because the same group of lamp beads 102 are located on the same fixed surface, the parameters α in the triangular model formed by the same group of lamp beads 102 are equal, and the same group of lamp beads 102 can be regarded as belonging to the same light source.
S110: the included angle between the fixing surface of the lamp shade 101 where the light source 100 is located and the horizontal plane is calculated by the reference height of the reference light source, the working distance between the reference light source and the target welding point 200, the included angle between the fixing surface of the lamp shade 101 where the reference light source is located and the horizontal plane, and the working distance between the light source 100 and the target welding point 200.
In one embodiment of the present application, on the premise that the diameter of the light emitting surface of the light source is not changed, that is, the diameter size of the lampshade 101 in the direction is not changed, the parameter of the light source 100 is obtained by changing the parameter α.
The reference light source refers to an existing light source, and therefore, each parameter of the reference light source is known. The reference light source can also create a similar triangular model. The reference light source and the desired light source 100 respectively establish a triangular model, and the parameters of the desired light source 100 can be obtained according to the relationship between the triangular model of the reference light source and the triangular model of the desired light source 100.
Regarding the light emitting surface diameter of the light source, for example, as shown in fig. 5, the plurality of lamp beads 102 are divided into three groups, each group of lamp beads 102 has one light emitting surface diameter, for example, the light emitting surface diameter of the red lamp bead 102 located at the top refers to the light emitting surface diameter D1 where the bottom lamp bead 102 located closest to the center of the lampshade 101 in the group of red lamp beads 102 is located, the light emitting surface diameter D2 of the middle group of lamp beads 102, and the light emitting surface diameter D3 of the lowest group of lamp beads 102.
As shown in fig. 6, the diameter of the light emitting surface of the light source is related to the field of view, D in fig. 6 is the diameter of the light emitting surface of the light source, fov is the size of the field of view, y is the working distance of the light source 100, the arrow points to the light direction of the simulated light source 100, and the diameter of the light emitting surface of the light source is at least 2 times the size of the field of view when the incident angle is equal to the reflection angle, so that the image effect is not affected. When the visual field is larger than one half of the diameter of the light emitting surface of the light source, the condition of uneven image color is presented on the slightly reflective PCB surface.
Further, the unchanged light emitting surface diameter of the light source means that the light emitting surface diameter of the reference light source is the same as the light emitting surface diameter of the required light source 100, the reference light source is an existing light source, and the light emitting surface diameter of the light source is known, so that the light emitting surface diameter of the required light source 100 can be determined.
The diameter of the light emitting surface of the light source is determined by the detection visual field, the detection visual field required by the light source 100 is determined according to the target welding point 200, and the diameter of the light emitting surface of the light source is determined according to the detection visual field, wherein the detection visual field is larger than or equal to one half of the diameter of the light emitting surface of the light source.
Specifically, referring to fig. 7, the setting parameters of the lamp bead 102 on the lamp shade 101 satisfy the following relation:
α1=90°-arctan((x+y1)(tan(90°-α))/(x+y)) （1）；
wherein x is the reference height of the reference light source and y is the distance between the reference light source and the target spot 200The working distance between the reference light source and the lamp shade 101 is alpha which is the included angle between the fixed surface of the reference light source and the horizontal plane; y is1Is the working distance, α, between the light source 100 and the target spot 2001Is the angle between the fixing surface of the lamp shade 101 where the light source 100 (i.e. the same group of lamp beads 102) is located and the horizontal plane.
Further, a right-angled triangle calculation model is established according to the fixing surface of the lamp bead 102 on the lamp shade 101, the light-emitting direction of the lamp bead 102 and the target plane where the target welding point 200 is located; taking the red annular light part as an example, the left edge of the dotted triangle in fig. 5 is a fixing surface of the lamp bead 102 (the default lamp bead 102 is perpendicular to the fixing surface), the right edge is a simulated emission light of the lamp bead 102 (the default lamp bead 102 is parallel to the lamp bead 102), and the lower edge is a target plane, namely the surface of the object to be measured (the circuit board to be measured); an included angle between the fixed surface and the light emitting direction of the lamp bead 102 is a right angle, an included angle between the fixed surface and the target plane is equal to an included angle alpha between the fixed surface and the horizontal plane, the sum of an included angle beta between the light emitting direction of the lamp bead 102 and the target plane and an included angle alpha between the fixed surface and the horizontal plane is equal to 90 degrees, alpha + beta =90 degrees, and the distance formed by the perpendicular line of the target plane passing through the right angle is the sum of x and y;
an included angle β between the light emitting direction of the lamp bead 102 of the reference light source and the target plane satisfies a relational expression, z = (x + y)/tan β (2); wherein x and z are known and constant values, and z is the dimension of a right-angle side of the target plane corresponding to tan beta;
obtaining the working distance y of the current lamp bead 1021The numerical value of (3) is substituted into the relational expression (2), and the included angle beta is calculated and obtained1；
According to beta1=90°-α1The relational expression (1) was obtained.
The method specifically comprises the following steps: building a triangle model according to the reference light source (the dotted triangle in fig. 7, the dotted triangle in fig. 7 is derived from the dotted triangle in fig. 5), then according to the triangle model, it can be known that:
z = (x+y)/tanβ （2）；
when the working distance y increases to the desired distance y1Then, a triangular model of the desired light source 100 is established (solid line in FIG. 7)Triangle), corresponding z1 = (x1+y1)/tanβ1In the embodiment, on the premise that the diameter of the light emitting surface of the light source is not changed, namely, the diameters of the required light source and the reference light source are consistent, the lamp bead 102 is always vertical to the lamp bead fixing surface, and the light emitted by the default lamp bead is always vertical to the lamp bead fixing surface; so when the working distance y increases to y1When each beam of light is expected to irradiate the original measured point, the angle alpha can be changed without changing the diameter; z is only an auxiliary calculated value, the right end point of the line segment z represents a measured point, the relative position of the measured point and the lamp bead of the reference light source is expected to be unchanged, so that the assumed z is unchanged, and since only the angle alpha is changed, x is also unchanged, so that x and z are unchanged, and x = x1，z= z1；
Thus beta in the triangular model of the desired light source 1001= arctan（（x+y1) Z) and beta1=90°-α1Thus, the following results:
α1=90°- arctan（（x+y1）/ z）=90°-arctan((x+y1)(tan(90°-α))/(x+y))；
thus, the diameter of the light emitting surface of the lamp housing 101 is known, the parameter α of the triangular model formed by the desired light source 100 is known, the reference height x of the reference light source is known, and the working distance y between the light source 100 and the target welding point 200 is known, so that the design size of the desired light source 100 can be obtained according to the parameters.
The design of the other two groups of beads 102 is the same as that described above, and details are not repeated here, and after the design sizes of the three groups of beads 102 are obtained, the required light source 100 can be obtained. H in FIG. 51For the height of the setting plane where the uppermost lamp bead group is located from the top of the lampshade 101, the same principle h2Height h from the set plane of the middle lamp bead group to the top of the lampshade 1013The height from the top of the lampshade 101 to the setting plane of the lowest lamp bead group, wherein the height x = h of the highest lamp bead group using the bottom plane of the lampshade 101 as the reference3－ h1The heights of the middle lamp bead group and the lowest lamp bead group which correspond to each other and take the bottom plane of the lampshade 101 as a reference are the same.
S120: according to the included angle between the fixed surface of the lampshade 101 where the light source 100 is located and the horizontal plane, the setting parameters of each lamp bead 102 on the inner wall of the lampshade 101 are respectively determined, and the required light source 100 is obtained.
According to the above relation (1), after the design parameters of the light source 100 of the three groups of beads 102 are determined, the required light source 100 can be obtained.
The above embodiment considers the detection efficiency while changing the angle of the ring light inside the AOI light source 100 according to the working distance of the light source 100 increased by the product features to achieve the same image effect under the condition that the diameter of the light emitting surface of the light source is not changed.
The same effect can be achieved by changing the diameter of the light emitting surface of the light source 100 without limitation of the mechanical position, and therefore in another embodiment of the present application, the required light source 100 is confirmed on the premise that the diameter of the light emitting surface of the light source is changed; specifically, after determining parameters of the lamp shade 101 and taking a distance between a pair of lamp beads 102 symmetrically arranged on a center line of the lamp shade 101 as a diameter of a light emitting surface of the light source of the lamp shade 101, the method further includes:
when the diameter of the light emitting surface of the light source is changed, a relational expression of the diameter of the light emitting surface of the light source is established, and the following requirements are met:
△r =△y/(tan(90°-α)) (3)；
where Δ r is the difference between the radius of the light source 100 and the radius of the reference light source, and Δ y is the required working distance to be increased.
When the diameter of the light emitting surface of the light source is changed, it can be understood that the required light source 100 is enlarged along the diameter direction of the light emitting surface of the light source on the basis of the reference light source, so that three corresponding angles in the triangular model of the reference light source and the triangular model of the required light source 100 are respectively equal.
As shown in FIG. 8, a triangle model is established, the dotted triangle is a reference light source model, the solid triangle is a desired light source 100 model, the diameter of the light emitting surface of the reference light source is smaller than that of the light emitting surface of the desired light source, α is the angle between the fixed surface of the light source 100 bead 102 and the horizontal plane, y is the angle between the fixed surface of the light source 100 bead 102 and the horizontal plane1(y + Deltay) is the working distance of the desired light source 100, Deltay is the working distance y compared to a reference light source,the required light source 100 needs to have an increased working distance height, x is the height of the light source 100 (x of the reference light source is equal to x of the required light source 100), Δ r is the difference of the radius of the light source 100 increased compared to the reference light source, the included angle between the light emitted by the light source 100 perpendicular to the fixed surface of the lamp bead 102 and the target horizontal plane is β, and the others are auxiliary calculated values. It can be seen that the light source 100 increases in the size of the reference light source by a difference Δ r in radius when the working distance Δ y is increased.
The model is calculated according to the right triangle, and the following results are obtained:
z1=△r +z （4）；
y1= y+△y （5）；
wherein z is the dimension of a square edge of the target plane corresponding to tan beta, y1Is the working distance of the light source 100;
the relational expressions (4) and (5) are substituted into the relational expression (2), and the relational expression (3) is obtained by setting the included angle β to a constant value.
In summary, the design method of the light source for solder joint detection provided by the embodiment of the present application is to obtain the parameter relation between the reference light source and the required light source 100 by establishing the triangle model based on the known reference light source, and calculate the parameter of the required light source 100.
The parameter calculation of the required light source 100 is divided into two cases, the first case is that under the condition that the diameter of the light emitting surface of the light source is not changed, the included angles alpha and beta of the triangular model of the reference light source and the corresponding included angle alpha in the triangular model of the required light source 1001、β1The corresponding values are not equal, i.e. alpha ≠ alpha1，β≠β1Calculating parameters of the required light source 100 according to the parameter relation between the reference light source and the triangular model of the required light source 100; in the second embodiment, in the case that the diameter of the light emitting surface of the light source is changed, the included angles α and β of the triangular model of the reference light source and the corresponding included angle α in the triangular model of the desired light source 100 are set1、β1The corresponding values are respectively equal, i.e. α = α1，β=β1Photo ofWhen the diameter of the reference light source along the light emitting surface of the light source is enlarged or reduced on the premise that the position angle is not changed in the triangular models of the reference light source and the required light source 100, the parameters of the required light source 100 can be calculated according to the parameter relation between the reference light source and the triangular model of the required light source 100.
It should be noted that the existing AOI light sources 100 are standard light sources 100, which are sufficient for testing, but far from enough to deal with PCB boards in different industries. Because the demands of the industries are different and the limitations are various, if the light source 100 is designed only by the supplier of the light source 100, a lot of time is spent for information synchronization with the manufacturer of the light source 100, and once a link and details are not clearly communicated in the middle, it is likely that not only the design period of the light source 100 is long, but also the project schedule is delayed, and even the light source 100 cannot be applied to the project at all.
By the method for designing the light source for detecting the welding spots, time is saved from the mode of requirement to test to the mode of design, the design period of the light source 100 is shortened, and the falling of projects is accelerated.
Therefore, the design method of the light source for detecting the welding spot provided by the embodiment of the application is efficient and multidimensional, can be used for 'medicine administration for the symptoms' without redundant steps, is simple and convenient, and is a comparison between the existing design mode and the design method of the embodiment of the application as follows:
the existing design method is as follows:
1) sequentially testing the standard annular red light sources 100 with the angles alpha of 30 degrees, 60 degrees and 90 degrees, and determining which light source 100 can better reflect the characteristics of the top of the welding spot;
2) if no proper angle exists, enlarging the diameter of the light emitting surface of the light source with the corresponding angle, and then trying;
3) if step 2) is not suitable, try again by finding an intermediate angle between two angles, for example, 45 ° or 80 ° of annular light source 100;
4) when the angle and the diameter of the light emitting surface of the light source 100 close to each other are found, the optimal diameter of the light emitting surface of the light source is continuously found by using a dichotomy;
5) after the red annular light source 100 is confirmed, sequentially trying the green annular light source 100 and the blue annular light source 100 according to the 4 steps until the light source 100 with a proper angle and a proper diameter of the light emitting surface is found;
6) combining the red ring light, the green ring light and the blue ring light found in the step 5), bonding the gaps by using an opaque material such as plasticine, performing optical test on a corresponding tested object, and finding out a proper brightness ratio;
7) if 6) the operation is not smooth, the proper light source 100 needs to be found again for matching, namely the previous 5 steps are repeated;
8) and if the test is relatively smooth, the corresponding design drawing is obtained by considering the design proportion according to the current combination condition.
The design method of the embodiment of the application comprises the following steps:
1) selecting a standard AOI light source 100 with a proper diameter of a light emitting surface of the light source 100 as a reference light source according to the visual field;
2) and directly calculating to obtain the design parameters of the required light source 100 through a triangular model according to the angle/light-emitting surface diameter parameter of the reference light source, the optimal working distance obtained through the lighting test and the project limiting conditions.
As can be seen from the above, the conventional design method obtains the required parameters of the light source 100 by trial and error step by step, and the obtained required parameters of the light source 100 are inevitably inaccurate, complicated in steps and long in time consumption; in the design method of the embodiment of the application, the required design parameters of the light source 100 are directly and accurately calculated by knowing the reference light source parameters on the basis of establishing the triangular model, so that the result is accurate and the efficiency is high.
On the other hand, referring to fig. 9, an embodiment of the present invention further provides a solder joint detection apparatus, including a light source 100 designed by the aforementioned design method for a solder joint detection light source, and a receiver 300 disposed on a light path, wherein a light beam emitted from the light source 100 irradiates a target solder joint 200 on a multi-solder joint circuit board, and the receiver 300 receives a light beam reflected by the target solder joint 200.
A through hole is formed in a lampshade 101 of the light source 100, the receiver 300 is arranged at the position of the through hole, light beams emitted by the light source 100 irradiate a target welding point 200 on the multi-welding-point circuit board and are reflected, and the reflected light is received by the receiver 300 through the through hole, so that the quality detection of the target welding point 200 is completed.
The above embodiments are merely examples of the present application and are not intended to limit the scope of the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims (9)
1. A design method of a light source for welding spot detection is used for welding spot detection of a multi-welding-spot circuit board, and is characterized by comprising the following steps:
providing a hemispherical lampshade, and annularly distributing a plurality of lamp beads on the inner wall of the lampshade;
calculating an included angle between a fixed surface of the lampshade where the light source is located and a horizontal plane through a reference height of the reference light source, a working distance between the reference light source and a target welding point, an included angle between the fixed surface of the lampshade where the reference light source is located and the horizontal plane, and a working distance between the light source and the target welding point;
respectively determining the setting parameters of each lamp bead on the inner wall of the lamp shade according to the included angle between the fixing surface of the lamp shade where the light source is located and the horizontal plane, and obtaining the required light source;
the calculating the included angle between the fixing surface of the lampshade where the light source is located and the horizontal plane through the reference height of the reference light source, the working distance between the reference light source and the target welding point, the included angle between the fixing surface of the lampshade where the reference light source is located and the horizontal plane, and the working distance between the light source and the target welding point comprises:
the lamp bead is arranged on the lampshade, and the setting parameters of the lamp bead meet the following relational expression:
α1=90°-arctan((x+y1)(tan(90°-α))/(x+y)) （1）；
wherein x is the reference height of the reference light source, y is the working distance between the reference light source and the target welding point, and alpha is the included angle between the fixed surface of the lampshade where the reference light source is located and the horizontal plane; y is1Is the working distance, alpha, between the light source and the target weld1The included angle between the fixed surface of the lampshade where the light source is located and the horizontal plane.
2. The design method of the light source for detecting the welding spots according to claim 1, wherein the setting parameters of the lamp bead on the lamp shade satisfy the following relation: alpha is alpha1=90°-arctan((x+y1) (tan (90 ° - α))/(x + y)) includes:
establishing a right-angled triangle calculation model according to the fixed surface of the lamp bead on the lamp shade, the light-emitting direction of the lamp bead and a target plane where a target welding point is located; the included angle between the fixed surface and the light-emitting direction of the lamp bead is a right angle, the included angle between the fixed surface and the target plane is equal to the included angle alpha between the fixed surface and the horizontal plane, the sum of the included angle beta between the light-emitting direction of the lamp bead and the target plane and the included angle alpha between the fixed surface and the horizontal plane is equal to 90 degrees, and the distance formed by the perpendicular line of the target plane passing through the right angle is the sum of x and y;
an included angle beta between the light-emitting direction of the lamp bead and the target plane satisfies a relational expression, and z = (x + y)/tan beta (2); wherein x and z are known and constant values, and z is the dimension of a square edge of the target plane corresponding to tan β;
obtaining the current working distance y of the lamp bead1Substituting the numerical value of (2) into the relational expression (2), and calculating to obtain the included angle beta1；
According to beta1=90°-α1The relational expression (1) was obtained.
3. The design method of the light source for detecting the welding spots according to claim 2, wherein the setting parameters of the lamp bead on the lamp shade satisfy the following relation: alpha is alpha1=90°-arctan((x+y1) (tan (90 ° - α))/(x + y)), the method further comprising:
and determining the diameter of the light emitting surface of the light source of the lampshade.
4. The design method of the light source for the welding spot detection as claimed in claim 3, wherein the determining the diameter of the light emitting surface of the light source of the lampshade comprises:
confirming a detection visual field required by the light source according to the target welding spot;
and determining the diameter of the light emitting surface of the light source according to the detection visual field, wherein the detection visual field is more than or equal to one half of the diameter of the light emitting surface of the light source.
5. The design method of the light source for solder joint inspection according to claim 4, wherein after determining the diameter of the light emitting surface of the light source of the lamp cover, the method further comprises:
when the diameter of the light emitting surface of the light source is changed, establishing a relational expression of the diameter of the light emitting surface of the light source, and satisfying the following conditions:
Δ r =Δy/(tan (90 ° - α)) (3); Δ r is the difference between the source radius and the reference source radius, and Δ y is the working distance that needs to be increased.
6. The method for designing the light source for detecting the welding spot according to claim 5, wherein when the diameter of the light emitting surface of the light source is changed, the relational expression of the diameter of the light emitting surface of the light source is established, and the requirement that Δ r =Δy/(tan (90 ° - α)) is satisfied comprises the following steps:
and calculating a model according to the right triangle to obtain:
z1=△r +z （4）；
y1= y+△y （5）；
wherein z is the dimension of one cathetus corresponding to tan beta and positioned on the target plane, y1Is the working distance of the light source;
substituting the relational expressions (4) and (5) into the relational expression (2), and obtaining the relational expression (3) according to the constant included angle beta.
7. The method as claimed in claim 1, wherein the providing of the hemispherical lampshade, the annularly distributing of the plurality of beads on the inner wall of the lampshade comprises:
the lamp beads are divided into at least three light source groups, the light source groups are arranged along the height of the lampshade in a stacked mode, and the light emitting colors of the lamp beads of the light source groups in the same group are the same.
8. The method as claimed in claim 7, wherein the light source groups include three light source groups, and the three light source groups are respectively a red light source group, a green light source group and a blue light source group along the height stacking direction of the lamp housing, and the red light source group is close to the top of the lamp housing.
9. A welding spot detection device, comprising a light source designed by the design method of the light source for welding spot detection according to any one of claims 1 to 8, and a receiver arranged on a light path, wherein a light beam emitted by the light source irradiates a target welding spot on a multi-welding-spot circuit board, and the receiver receives the light beam reflected by the target welding spot.
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| Publication number | Priority date | Publication date | Assignee | Title |
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