TO packaging chip size detection method and system

Abstract

The invention discloses a TO packaging chip size detection method and system, a TO packaging chip comprises a plastic packaging body and a plurality of pins, each pin comprises an unbent part and a bent part, and the detection method comprises the steps: taking points at the tail ends of the first surfaces of the bent parts of the pins, and carrying out the fitting of the points to generate corresponding first line segments; the first surface is a surface which is perpendicular to the end surface of the bending part and is used for being attached to the surface of a bonding pad on the PCB in the bending part; measuring the distance between the first line segments corresponding to the pins on the same side of the plastic package body to obtain the pin spacing between the corresponding pins; and selecting a reference pin, and detecting the included angle between the first line segment corresponding to the other pins and the first line segment corresponding to the reference pin to obtain the included angle between the pins. According to the technical scheme disclosed by the invention, points are taken at the tail ends of the surfaces which are not bent in the bent parts of the pins, so that the accuracy of pin spacing detection is improved, and the detection of included angles between the pins is also realized, so that the accuracy of defective product screening is improved.

Description

Technical Field

[0001] The present application relates to the technical field of product size testing, and more specifically, to a TO package chip size detection method and system. Background Art

[0002] TO (Transistor Outline) package is a coaxial device package. In order to improve the reliability of TO package chips during operation, many end customers choose to bend the pins of TO package chips into different shapes and then mount them on the PCB (printed circuit board).

[0003] In order to ensure the patch quality of the TO package chip pins and PCB pads, it is necessary to perform size detection on the TO package chip to accurately detect the size defects of the TO package chip pins. The known TO package chip size detection method is to take a point at the root of the bent part of the middle pin (that is, the arc position where the pin is bent) to generate a reference line, and then take a point on the end face of other pins, generate the middle point of the end face according to the point taken on the end face, and obtain the length of the vertical line segment from the middle point to the reference line. The length of the vertical line segment is the pin spacing. The above-mentioned size detection method will not only cause difficulty in taking points and errors in taking points due to taking points at the bent part, thereby causing size detection errors, but also fail to accurately determine the pin size defects by only performing a single size measurement, resulting in the inability to accurately screen out products with size defects.

[0004] In summary, how to improve the accuracy and diversity of TO package chip pin size detection so as to accurately screen out defective products is a technical problem that needs to be urgently solved by technical personnel in this field. Summary of the invention

[0005] In view of this, the purpose of the present application is to provide a TO package chip size detection method and system for improving the accuracy and diversity of TO package chip pin size detection so as to accurately screen out defective products.

[0006] In order to achieve the above objectives, this application provides the following technical solutions:

[0007] A TO package chip size detection method, the TO package chip includes a plastic package and a plurality of pins, each of the pins includes an unbent portion and a bent portion, the unbent portion is connected to the plastic package, the TO package chip size detection method includes:

[0008] A point is taken at the end of the first surface of the bent portion of each pin, and a first line segment corresponding to each pin is generated by fitting; the first surface of the bent portion is a surface of the bent portion that is perpendicular to the end surface of the bent portion and the surface of the bent portion that is used to fit with the pad on the PCB;

[0009] Measuring the distance between the first line segments corresponding to the pins located on the same side of the plastic package body to obtain the pin spacing between the corresponding pins;

[0010] A reference pin is selected from the plurality of pins, and the angles between the first line segments corresponding to the remaining pins and the first line segment corresponding to the reference pin are detected to obtain the angle between the corresponding pin and the reference pin.

[0011] Preferably, after obtaining the angle between the reference pin and the corresponding pin, the method further comprises:

[0012] Taking each of the pins as a reference pin, respectively, obtaining the pin spacing and angle corresponding to the reference pin from the detected pin spacing and angle between the pins;

[0013] According to the pin spacing and angle corresponding to the reference pin, judging whether the contact area between the reference pin and the pad on the PCB meets the preset welding condition;

[0014] If not, it is determined that the pins of the TO packaged chip have size defects.

[0015] Preferably, judging whether the contact area between the reference pin and the pad on the PCB meets a preset welding condition according to the pin spacing and the angle corresponding to the reference pin includes:

[0016] Determine the pin swing angle value range corresponding to the reference pin according to the pre-established correspondence relationship between the pin spacing offset tolerance and the pin swing angle and the pin spacing corresponding to the reference pin;

[0017] Determine whether the angle corresponding to the reference pin is within the corresponding pin swing angle value range;

[0018] If so, determining that the contact area between the reference pin and the pad satisfies the preset welding condition;

[0019] Wherein, the corresponding relationship is established according to the preset welding conditions, the pin spacing offset tolerance and the pin swing angle.

[0020] Preferably, it also includes:

[0021] When the pin is bent in an L-shape, a point is taken on the second surface of the bent portion of each pin, and a second line segment corresponding to each pin is generated by fitting; a point is taken on the second surface of the unbent portion of each pin, and a third line segment corresponding to each pin is generated by fitting; the angle between the second line segment and the third line segment corresponding to the pin is measured to obtain the first bending angle of the pin; the second surface of the bent portion is a surface of the bent portion that is parallel to the surface that fits with the pad, and the second surface of the unbent portion is a surface of the unbent portion that is adjacent to the second surface of the bent portion;

[0022] When the pin is V-shaped bent, a point is taken on the second surface of the first bent portion of each pin, and a fourth line segment corresponding to each pin is generated by fitting; a point is taken on the second surface of the second bent portion of each pin, and a fifth line segment corresponding to each pin is generated by fitting; the angle between the fourth line segment and the fifth line segment corresponding to the pin, and the angle between the third line segment and the fifth line segment are measured to obtain the second bending angle and the third bending angle of the pin accordingly; the first bent portion is adjacent to the second bent portion and the first bent portion is used to fit with the soldering pad of the PCB, the second bent portion is adjacent to the unbent portion, the second surface of the first bent portion is a surface in the first bent portion that is parallel to the surface used to fit with the soldering pad, and the second surface of the second bent portion is adjacent to the second surface of the first bent portion.

[0023] Preferably, it also includes:

[0024] Take a point on the first surface of the unbent portion of each pin, and fit and generate a sixth line segment corresponding to each pin; the first surface of the unbent portion is opposite to the second surface of the unbent portion;

[0025] Generate a pin centerline corresponding to the pin according to the third line segment and the sixth line segment corresponding to the pin, take points on the second surface of the plastic package body and generate the line segment corresponding to the plastic package body by fitting, measure the angle between the line segment corresponding to the plastic package body and the pin centerline corresponding to the pin to obtain the angle between the pin and the plastic package body; the second surface of the plastic package body and the second surface of the unbent portion of the pin are located on the same side;

[0026] Take a point on the joint surface of the plastic package and the pin to generate a vertical line, obtain the intersection point of the vertical line and the pin center line corresponding to the pin, and use the intersection point as the intersection point of the vertical center line corresponding to the pin;

[0027] When the pin is bent in an L-shape, the distance between the intersection of the vertical midlines corresponding to the pin and the second line segment corresponding to the pin is measured to obtain the length of the unbent portion of the pin.

[0028] Preferably, it also includes:

[0029] When the pin is bent in an L-shape, a point is taken on the end surface of the bent portion; when the pin is bent in a V-shape, a point is taken on the end surface of the first bent portion, and a seventh line segment corresponding to the pin is obtained by fitting;

[0030] The distance between the seventh line segment corresponding to the pin and the pin center line corresponding to the pin is measured to obtain the length of the bent portion of the pin.

[0031] Preferably, it also includes:

[0032] When the pin is bent in an L-shape, a point is taken on the surface of the bent portion for fitting with the pad, and an eighth line segment corresponding to the pin is generated by fitting; and a distance between the eighth line segment and the second line segment is measured to obtain the single-side coplanarity of the pin;

[0033] When the pin is bent in a V-shape, a point is taken on the surface of the first bent portion that is fitted with the pad, and a ninth line segment corresponding to the pin is generated by fitting; the distance between the ninth line segment and the fourth line segment is measured to obtain the single-sided coplanarity of the pin.

[0034] Preferably, it also includes:

[0035] A point is taken at the end of the third surface of the unbent portion of the pin, and a tenth line segment corresponding to each pin is generated by fitting; the third surface of the unbent portion is parallel to the first surface of the bent portion;

[0036] The distance between the tenth line segments corresponding to two adjacent pins is measured to obtain the pin spacing between the two adjacent pins.

[0037] Preferably, it also includes:

[0038] Points are taken at the end of the second surface of the bent portion of the pin, and the distances from each point to the reference plane are measured, and the average value of the distances is calculated as the distance from the bent portion corresponding to the pin to the reference plane; the second surface of the bent portion is a surface parallel to the surface of the bent portion used to fit with the pad, and the reference plane is parallel to the surface of the bent portion used to fit with the pad;

[0039] A maximum distance and a minimum distance are selected from the distances from the bent portions corresponding to the pins to the reference plane, and the coplanarity between the pins is obtained according to the maximum distance and the minimum distance.

[0040] A TO package chip size detection system, comprising:

[0041] The first camera is used to take a point at the end of the first surface of the bending part of each pin, and fit to generate a first line segment corresponding to each pin; the first surface of the bending part is a surface in the bending part that is perpendicular to the end face of the bending part and the surface of the bending part used to fit with the pad on the PCB; measure the distance between the first line segments corresponding to the pins located on the same side of the plastic package to obtain the pin spacing between the corresponding pins; select a reference pin from the multiple pins, and detect the angle between the first line segments corresponding to the remaining pins and the first line segment corresponding to the reference pin to obtain the angle between the corresponding pin and the reference pin.

[0042] The present application provides a TO package chip size detection method and system. The TO package chip includes a plastic package and a plurality of pins. Each pin includes an unbent portion and a bent portion. The unbent portion is connected to the plastic package. The TO package chip size detection method includes: taking a point at the end of the first surface of the bent portion of each pin, and fitting to generate a first line segment corresponding to each pin; the first surface of the bent portion is a surface of the bent portion that is perpendicular to the end surface of the bent portion and the surface of the bent portion that is used to fit with a pad on a PCB; measuring the distance between the first line segments corresponding to the pins located on the same side of the plastic package to obtain the pin spacing between the corresponding pins; selecting a reference pin from the plurality of pins, and detecting the angle between the first line segments corresponding to the remaining pins and the first line segment corresponding to the reference pin to obtain the angle between the corresponding pin and the reference pin.

[0043] The above technical solution disclosed in the present application is to take points at the end of the first surface of the bent part of the pin and fit to generate the first line segment corresponding to each pin, and use the first line segment to detect the pin spacing, wherein the first surface of the bent part is a surface in the bent part that is perpendicular to the end face of the bent part and the surface in the bent part that is used to fit with the pad on the PCB, so as to avoid the situation of difficulty in taking points and inaccurate point taking by taking points on the surface that has not been bent in the bent part of the pin, thereby improving the accuracy of pin spacing detection, and because the end will be more serious when the pin collides, etc., therefore, fitting the point-taking line segment at the end can more accurately detect the pin spacing, so as to improve the screening of defective TO package chips. In addition, the present application not only detects the pin spacing, but also detects the angle between the pins based on the first line segment obtained by fitting, so as to realize the diversified detection of the pin size of the TO package chip, so as to facilitate more accurate determination of whether there is a quality risk when the pin is mounted on the PCB pad, thereby improving the reliability and accuracy of the screening of defective TO package chips. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0045] Figure 1 It is a schematic diagram of the pin size detection of a known TO package chip;

[0046] Figure 2 A flow chart of a TO package chip size detection method provided in an embodiment of the present application;

[0047] Figure 3 A schematic diagram of an L-shaped bend of a TO94-BL package chip provided in an embodiment of the present application;

[0048] Figure 4 A schematic diagram of a V-shaped bend of a TO94-BL package chip provided in an embodiment of the present application;

[0049] Figure 5 Provided in the embodiments of this application Figure 3 One of the views;

[0050] Figure 6 A schematic diagram of the dimensions of the bending portion of the TO94-BL provided in the embodiment of the present application;

[0051] Figure 7 A schematic diagram showing the pins provided in the embodiment of the present application coinciding with the center lines of the pads;

[0052] Figure 8 This is a schematic diagram of a case where there is no swing angle between the pin and the pad and the contact area between the pin and the pad is 3 / 4 provided in an embodiment of the present application;

[0053] Fig. 9 A schematic diagram of a case where the contact area between the pins and the pad is 3 / 4 when there is no deviation in the center spacing of the pins provided in the embodiment of the present application and the pins have a swing angle;

[0054] Fig.10 A schematic diagram of a pin contact area with a pad of 3 / 4 when the pins provided in the embodiment of the present application have both a change in center spacing and a swing angle;

[0055] Fig.11 Provided in the embodiments of this application Figure 3 Another view of;

[0056] Fig.12 Provided in the embodiments of this application Figure 3 Another view of;

[0057] Fig.13 A schematic diagram of measuring the pin spacing provided in an embodiment of the present application;

[0058] Fig.14 Schematic diagram of the distribution relationship between the TO packaged chip and the reference plane provided in an embodiment of the present application. DETAILED DESCRIPTION

[0059] TO package is a coaxial device packaging form. Taking the TO94 packaged automotive magnetic sensor product as an example, it requires the chip plastic package to stand on the PCB, and the Hall sensor inside the chip is used to test the current conduction of the adjacent wires. The traditional method is to insert the four pins of the TO94 packaged chip into the corresponding slots. However, this solution will lead to poor stability of the chip in the slot, and position shift will occur in harsh automotive application environments, resulting in inaccurate test results, or even direct chip breakage.

[0060] In order to ensure the reliability of TO packaged chips on PCBs and the stability of chip operation, many end customers choose to bend the pins of TO packaged chips into different shapes before mounting them on PCBs. For bent TO packaged chips, it is necessary to accurately detect the size defects of the pins to ensure the quality of the fitting between the pins of TO packaged chips and PCBs.

[0061] like Figure 1 As shown, it shows a schematic diagram of the known TO package chip pin size detection, wherein, Figure 1 Take the TO94 package as an example. Its implementation structure is to take point 1 and point 2 at the root of the bent part of the two middle pins (pin 2, pin 3), and generate point 3 and the middle reference line based on point 1 and point 2, and take point 4 and point 5 at the end face of each pin to generate point 6. The length of the vertical line segment from point 6 to the middle reference line is used as the pin spacing. However, since the root of the bent part of the chip is the bend of the chip, and the bend is an arc, it will make it difficult to take the point, and in fact the point captured by the camera may not be fixed with the distance from the camera, resulting in point taking errors. Moreover, the above-mentioned point taking at the root as the reference point is the default position of the unbent pin relative to the plastic package body is accurate, but in fact the two are offset, resulting in reference point errors. In addition, the above-mentioned only performs a single pin spacing detection, so it is impossible to more accurately detect the size defects of the TO package chip pins.

[0062] To this end, the present application provides a TO package chip size detection method and system for improving the accuracy and diversity of TO package chip pin size detection so as to accurately screen out defective products.

[0063] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0064] See also Figures 2 to 5 ,in, Figure 2 A flow chart of a TO package chip size detection method provided in an embodiment of the present application is shown. Figure 3 A schematic diagram of an L-shaped bend of a TO94-BL package chip provided in an embodiment of the present application is shown. Figure 4 A schematic diagram of a V-shaped bend of a TO94-BL package chip provided in an embodiment of the present application is shown. Figure 5 Shows Figure 3 An embodiment of the present application provides a TO package chip size detection method, wherein the TO package chip includes a plastic package and a plurality of pins, each pin includes an unbent portion and a bent portion, and the unbent portion is connected to the plastic package. The TO package chip size detection method may include:

[0065] S11: Take a point at the end of the first surface of the bending part of each pin, and fit to generate the first line segment corresponding to each pin; the first surface of the bending part is a surface of the bending part that is perpendicular to the end face of the bending part and the surface of the bending part used to fit with the pad on the PCB.

[0066] The TO package chip specifically includes a plastic package and a plurality of pins connected to the plastic package, each pin includes an unbent portion connected to the plastic package and a bent portion adjacent to the unbent portion. The pins can be specifically L-shaped or V-shaped. Figure 3 and Figure 4 As shown, BL represents the chip that needs to be bent and then mounted on the PCB. Figure 3-Figure 5 Take the TO94 package as an example, which is a common package, including four pins L1, L2, L3 and L4. Of course, the present application can also be applied to packages similar to the TO94 package, such as TO3, TO18, TO92S, etc., which require pins to be bent before being mounted on the PCB.

[0067] When performing size inspection on a TO packaged chip, a first camera can be used to take points at the end of the first surface of the bending portion of each pin included in the TO packaged chip, and the points taken at the end of the first surface of the bending portion of the corresponding pin can be fitted to generate first line segments corresponding to each pin. The first surface of the bending portion of each pin refers to the same surface, that is, the point-taking objects of each pin need to remain the same to improve the accuracy of the pin spacing measurement. The first surface of the bending portion is a surface in the bending portion that is perpendicular to the end face of the bending portion and the surface in the bending portion that is used to fit with the pad on the PCB (that is, the patch surface of the pin in the TO packaged chip). The end face of the bending portion is the surface at the end of the bending portion and has the smallest area among the surfaces of the bending portion, that is, the surface corresponding to the end of the pin. In addition, the end of the first surface means that it is still on the first surface, but it is in the end area. Figure 5 Taking the shown view as an example, a point can be taken at the end of the upper surface of the bent part of each pin (i.e., the position surrounded by the dotted line frame), and the first line segment corresponding to each pin can be generated by fitting. Of course, a point can also be taken at the end of the lower surface of the bent part of each pin, and the first line segment corresponding to each pin can be generated by fitting. This application does not limit the upper surface and the lower surface, as long as the selection objects of all pins remain consistent.

[0068] From the above, it can be seen that compared with the existing method of taking points at the position where the pin is bent, the present application takes points on the first surface of the bent part of the pin, that is, taking points on the surface of the pin that has not been bent, which can solve the problem of difficulty in taking points and avoid inaccurate point taking, and can more accurately detect the pin spacing. Moreover, the present application takes points at the end of the first surface because the area away from the plastic package (that is, the end area of ​​the bent part) will be more serious when the pin is collided and bent. From the figure, it can be seen that the top of the pin in the dotted box is the most serious. Therefore, by taking points at the end of the first surface of the bent part, the measurement error can be effectively avoided to improve the accuracy of the pin spacing measurement, thereby facilitating the improvement of the accuracy of the determination of the TO package chip pin size defects, so as to accurately distinguish good products from defective products.

[0069] In order to ensure the stability and accuracy of the measurement, the plastic package of the TO packaged chip can be attached to the fixture.

[0070] S12: measuring the distance between the first line segments corresponding to the pins located on the same side of the plastic package body to obtain the pin spacing between the corresponding pins.

[0071] Considering that the first line segments corresponding to the pins located on the same side of the plastic package are located at the same position, while the first line segments corresponding to the pins located on different sides of the plastic package are not at the same position, therefore, when the first line segments corresponding to the pins are used to measure the pin spacing of the pins located on different sides of the plastic package, the extension line of the first line segment is required. If there is an angle between the two pins, this method of measuring the pin spacing will have an error. When the first line segments corresponding to the pins are used to measure the pin spacing of the pins located on the same side of the plastic package, the extension line of the first line segment is not required. Therefore, accurate measurement of the pin spacing can be achieved. Based on the above considerations, the present application measures the distance between the first line segments corresponding to the corresponding pins for the pins located on the same side of the plastic package to obtain the pin spacing of the corresponding pins, wherein the pin spacing is the spacing between the bent portions of the corresponding pins.

[0072] Specifically, after fitting and generating the first line segments corresponding to each pin, the midpoint of the first line segment corresponding to one of the pins can be calculated based on the first line segment corresponding to the pin, and the length of the perpendicular line segment from the midpoint of the first line segment corresponding to the pin to the first line segment corresponding to another pin on the same side can be measured to obtain the pin spacing between the corresponding pins. Of course, when measuring the distance between the first line segments corresponding to the pins on the same side, it can also be achieved by selecting any point on the first line segment corresponding to one of the pins and measuring the length of the perpendicular line segment from the point to the first line segment corresponding to the other pin on the same side.

[0073] Among them, the measured pin spacing between corresponding pins can reflect the spacing offset between each pin and the corresponding PCB pad (specifically, the spacing offset between the center line of the pin and the center line of the PCB pad), that is, for two pins, they can be used as references for each other. Specifically, when one of the two pins is used as a reference pin, it is assumed that there is no deviation between the reference pin and its corresponding pad, and the pin spacing between the reference pin and the other pin can be regarded as the spacing deviation between the other pin and its corresponding pad; when the other pin of the two pins is used as a reference pin, it is assumed that there is no deviation between the reference pin and its corresponding pad, and the pin spacing between the pin and the other pin can be regarded as the spacing deviation between the other pin and its corresponding pad.

[0074] It should be noted that when the same side of the plastic package body contains only one pin, the pin may not be subjected to the above step S12. When the same side of the plastic package body contains more than two pins, the pin spacing detection may be performed in step S12 between any two pins located on the same side of the plastic package body, or the pin spacing detection may be performed in step S12 between two adjacent pins.

[0075] Take the TO94 package as an example, for details, please refer to Figure 5, points can be taken at the ends of the upper surfaces of the top of the L1 pin after bending and the L4 pin after bending to generate the first line segments corresponding to the L1 pin and the L4 pin respectively. Since the L1 pin and the L4 pin are located on the same side of the plastic package body, and the L1 pin and the L2 pin are located on one side of the plastic package body, the pin spacing of the L1 pin and the L4 pin can be measured, and the pin spacing of the L1 pin and the L2 pin can be measured. Specifically, for the first line segment corresponding to the L4 pin, its midpoint can be calculated, and the length of the vertical line segment from the midpoint of the first line segment corresponding to the L4 pin to the first line segment corresponding to the L1 pin can be obtained, and the length of the vertical line segment can be used as the pin spacing between the L1 pin and the L4 pin. For the first line segment corresponding to the L2 pin, its midpoint can be calculated, and the length of the vertical line segment from the midpoint of the first line segment corresponding to the L2 pin to the first line segment corresponding to the L3 pin can be obtained, and the length of the vertical line segment can be used as the pin spacing between the L2 pin and the L3 pin. Among them, the measured pin spacing between L1 pin and L4 pin can reflect the spacing deviation between L1 pin, L4 pin and their corresponding pads, and the measured pin spacing between L2 pin and L3 pin can reflect the spacing deviation between L2 pin, L3 pin and their corresponding pads.

[0076] Since the pins on the same side of the plastic package have corresponding first line segments at the same position, measuring the distance between the first line segments on the same side of the plastic package as the pin spacing between the corresponding pins can improve the accuracy of the pin spacing measurement and avoid measurement errors.

[0077] Of course, the present application can also measure the distance between the first line segments corresponding to any two pins to obtain the pin spacing between any two pins, thereby facilitating the tester to obtain more pin size information.

[0078] S13: Select a reference pin from the plurality of pins, and detect the angles between the first line segments corresponding to the remaining pins and the first line segment corresponding to the reference pin to obtain the angle between the corresponding pin and the reference pin.

[0079] Taking into account that the same pin may have both spacing deviation and angle deviation, for this reason, the present application can not only use the first line segment corresponding to the pin to detect the pin spacing, but also use the first line segment corresponding to the pin to detect the angle between the pins, so as to realize the detection of the pin size from multiple dimensions and realize diversified detection of the pin size, so as to facilitate more accurate determination of the pin size defects, thereby improving the reliability and accuracy of the screening of defective TO packaged chips.

[0080] For the measurement of the pin angle, after step S11, a reference pin can be selected from the multiple pins included in the TO package chip. Specifically, a pin located at the outermost side can be selected as the reference pin. Of course, other pins can also be selected as reference pins. Afterwards, the angle between the first line segment corresponding to the remaining pins and the first line segment corresponding to the reference pin can be detected. Specifically, the angle between the extension line of the first line segment corresponding to the remaining pins and the extension line of the first line segment corresponding to the reference pin can be detected, and the angle is used as the angle between the corresponding pin and the reference pin. It should be noted that there is no order limit between step S12 and step 13.

[0081] Among them, the measured angle between the corresponding pins can reflect the angular deviation between each pin and its corresponding PCB pad (specifically, the angular deviation between the center line of the pin and the center line of the PCB pad). That is, for two pins, they can serve as a reference for each other to reflect the angular deviation between each pin and its corresponding PCB pad.

[0082] by Figure 5 For example, select L1 pin as the reference pin, use the first line segment corresponding to L2 pin and the first line segment corresponding to L1 pin to detect the angle between L2 pin and L1 pin, use the first line segment corresponding to L3 pin and the first line segment corresponding to L1 pin to detect the angle between L3 pin and L1 pin, use the first line segment corresponding to L4 pin and the first line segment corresponding to L1 pin to detect the angle between L4 pin and L1 pin.

[0083] From the above, it can be known that the present application can not only realize the detection of pin spacing, but also realize the detection of angles between pins, so as to realize multi-dimensional size detection of TO package chip pins, improve the diversity of pin size detection, and thus facilitate more accurate determination of the welding quality between the pins and the corresponding pads based on the detected pin spacing and pin angles, and improve the accuracy of determining pin size defects, thereby improving the screening and differentiation capabilities of good TO package chips and defective TO package chips. In addition, the pin spacing detection and pin angle detection of the present application are both realized by taking points at the end of the first surface of the pin bending part to fit and generate line segments and based on the fitted generated line segments, so it is easy and accurate to take points, thereby improving the accuracy of pin spacing detection and pin angle detection.

[0084] The above technical solution disclosed in the present application is to take points at the end of the first surface of the bent part of the pin and fit to generate the first line segment corresponding to each pin, and use the first line segment to detect the pin spacing, wherein the first surface of the bent part is a surface in the bent part that is perpendicular to the end face of the bent part and the surface in the bent part that is used to fit with the pad on the PCB, so as to avoid the situation of difficulty in taking points and inaccurate point taking by taking points on the surface that has not been bent in the bent part of the pin, thereby improving the accuracy of pin spacing detection, and because the end will be more serious when the pin collides, etc., therefore, fitting the point-taking line segment at the end can more accurately detect the pin spacing, so as to improve the screening of defective TO package chips. In addition, the present application not only detects the pin spacing, but also detects the angle difference between the pins based on the first line segment obtained by fitting, so as to realize the diversified detection of the pin size of the TO package chip, so as to facilitate more accurate determination of whether there is a quality risk when the pin is mounted on the PCB pad, thereby improving the reliability and accuracy of the screening of defective TO package chips.

[0085] A TO package chip size detection method provided in an embodiment of the present application may further include, after obtaining the angle between the reference pin and the corresponding pin:

[0086] Taking each pin as a reference pin, respectively, obtaining the pin spacing and angle corresponding to the reference pin from the detected pin spacing and angle between the pins;

[0087] According to the pin spacing and angle corresponding to the reference pin, determine whether the contact area between the reference pin and the pad on the PCB meets the preset welding conditions;

[0088] If not, it is determined that the pins of the TO packaged chip have size defects.

[0089] Considering that when the pins of the TO package chip are welded to the PCB pad, if there is a spacing deviation and / or an angle deviation and the deviation causes the pin and the pad to have insufficient welding area, the welding will be unstable and quality risks will be generated. In order to ensure the welding effect and meet the welding effect, the contact area between the pin and the pad needs to be greater than a certain value. For example, the IPC-A-610H standard stipulates that the contact area between the pin and the pad needs to be greater than 3 / 4 of the pin horizontal area. Based on this consideration, after obtaining the angle between the reference pin and the corresponding pin, each pin can be used as a reference pin, and the pin spacing and angle corresponding to the reference pin (i.e., the pin spacing and angle associated with the reference pin) can be obtained from the pin spacing and the angle between the pins obtained by the above detection. Afterwards, the contact area between the reference pin and the corresponding pad on the PCB is judged according to the pin spacing and angle corresponding to the reference pin to determine whether it meets the preset welding conditions. For example, the preset welding condition can be greater than 3 / 4 of the pin horizontal area, or the preset welding condition can be set according to other requirements. When making a judgment, the contact area between the pin and the pad can be calculated according to the pin spacing and angle associated with the reference pin, so as to make a judgment based on the calculated contact area. When it is determined that the contact area between the reference pin and the pad on the PCB does not meet the preset welding condition, it is determined that the pin of the TO package chip has a size defect, and a prompt can be issued. When it is determined that the contact area between the reference pin and the pad on the PCB meets the preset welding condition, it indicates that the pin of the TO package chip has no size defects in the pin spacing and angle.

[0090] Specifically, Figure 5For example, it can be known from the above that the pin spacing of L1 pin and L4 pin, the pin spacing of L2 pin and L3 pin, the angle between L1 pin and L2 pin, the angle between L1 pin and L3 pin, and the angle between L1 pin and L4 pin are detected respectively. When L1 pin is used as the reference pin, the pin spacing of L1 pin and L4 pin associated with L1 pin and the angle between L1 pin and L4 pin can be obtained, and then it can be judged whether the contact area between L1 pin and the pad of the pin on PCB meets the preset welding condition according to the pin spacing of L1 pin and L4 pin associated with L1 pin and the angle between L1 pin and L4 pin; when L2 pin is used as the reference pin, the pin spacing of L2 pin and L3 pin associated with L2 pin and the angle between L1 pin and L2 pin can be obtained, and it can be judged whether the contact area between L2 pin and the pad of the pin on PCB meets the preset welding condition according to the pin spacing of L2 pin and L3 pin associated with L2 pin and the angle between L1 pin and L2 pin. When the L3 pin is used as the reference pin, the pin spacing of the L2 pin and the L3 pin associated with the L3 pin and the angle between the L1 pin and the L3 pin can be obtained, and according to the pin spacing of the L2 pin and the L3 pin associated with the L3 pin and the angle between the L1 pin and the L3 pin, it is judged whether the contact area between the L3 pin and the pad of the pin on the PCB meets the preset welding condition; when the L4 pin is used as the reference pin, the pin spacing of the L1 pin and the L4 pin associated with the L4 pin and the angle between the L1 pin and the L4 pin can be obtained, and according to the pin spacing of the L1 pin and the L4 pin associated with the L4 pin and the angle between the L1 pin and the L4 pin, it is judged whether the contact area between the L4 pin and the pad of the pin on the PCB meets the preset welding condition.

[0091] By judging whether the contact area between the reference pin and the pad meets the preset welding conditions according to the pin spacing and the angle, the welding quality between the pin and the corresponding pad can be automatically, efficiently and accurately judged, thereby improving the efficiency and accuracy of TO package chip pin size defect detection.

[0092] A TO package chip size detection method provided in an embodiment of the present application determines whether the contact area between the reference pin and the pad on the PCB meets the preset welding condition according to the pin spacing and angle corresponding to the reference pin, and may include:

[0093] Determine the pin swing angle value range corresponding to the reference pin according to the pre-established correspondence between the pin spacing offset tolerance and the pin swing angle and the pin spacing corresponding to the reference pin;

[0094] Determine whether the angle corresponding to the reference pin is within the pin swing angle value range corresponding to the corresponding pin;

[0095] If so, determining that the contact area between the reference pin and the pad satisfies the preset welding condition;

[0096] The corresponding relationship is established according to the preset welding conditions, the pin spacing offset tolerance and the pin swing angle.

[0097] In the present application, the corresponding relationship between the pin spacing offset tolerance and the pin swing angle can be established in advance according to the preset welding conditions, the pin spacing offset tolerance (i.e., the offset distance between the pin centerline and the pad centerline) and the pin swing angle (i.e., the swing angle between the pin centerline and the pad centerline). Specifically, the limit value of the pin spacing offset tolerance can be determined according to the critical conditions of the preset welding conditions, and the limit value of the pin swing angle can be determined according to the critical conditions of the preset welding conditions. According to the critical conditions of the preset welding conditions, the limit value of the pin spacing offset tolerance and the limit value of the pin swing angle, the corresponding relationship between the pin spacing offset tolerance and the pin swing angle is established, wherein in this relationship, the pin spacing offset tolerance is divided into a plurality of pin spacing offset tolerance intervals, each pin spacing offset tolerance interval corresponds to a respective pin swing angle range, and when the pin spacing is within any pin spacing offset tolerance interval in the corresponding relationship, if the angle between the pins corresponding to the pin spacing is within the pin swing angle range corresponding to the above pin spacing offset tolerance interval, it is determined that the pin spacing and the corresponding angle between the pins are within a reasonable tolerance range, that is, the welding area between the corresponding pin and the pad meets the preset welding conditions.

[0098] Taking the preset welding condition that the contact area between the pin and the pad must be larger than 3 / 4 of the horizontal area of ​​the pin as an example, that is, the welding effect can only be guaranteed when the contact area between the pin and the pad must be larger than 3 / 4 of the horizontal area of ​​the pin. The spacing between the pin centers and the swing angle amplitude need to be controlled with tolerance to meet the welding requirements.

[0099] For details, please refer to Figure 6-Figure 10 ,in, Figure 6 The schematic diagram of the bending part size of TO94-BL is shown. Figure 7 The schematic diagram shows the situation when the pin and the center line of the pad coincide. Figure 8 The schematic diagram shows that there is no swing angle between the pin and the pad and the contact area between the pin and the pad is 3 / 4. Fig. 9 It shows a schematic diagram of the pin-pad contact area of ​​3 / 4 when there is no deviation in the pin center spacing and the pin has a swing angle. Fig.10 The schematic diagram shows that the contact area between the pin and the pad is 3 / 4 when the pin has both a change in center spacing and a swing angle. Among them, the pad width dimension a = 0.6mm, the pin width dimension b = 0.4mm, the pin thickness dimension t = 0.2mm, the horizontal length dimension of the pin after bending is l = 4.3mm, the theoretical center distance between the L1 pin and the L4 pin is 3.81mm, and the theoretical center distance between the L2 pin and the L3 pin is 1.27mm. The calculation of the corresponding relationship is as follows:

[0100] 1) When the pin does not have a swing angle and only the center spacing changes, the position of the pin and the pad is as follows Figure 7 and Figure 8 When the contact area between the pad and the pin is 3 / 4, the pin center offset distance x = (ab) / 2 + b × 1 / 4, which is the limit value of the offset distance in a single direction. Since b = 0.4mm, x = (0.6-0.4) / 2 + 0.4 × 1 / 4 = 0.2mm, and the tolerance of the pin spacing is ±0.2mm;

[0101] 2) When the pin center spacing has no deviation and only the swing angle changes, the extreme position relationship between the pin and the pad is as follows: Fig. 9 As shown. In the case of a swing angle, when the effective contact area between the pad and the pin is 3 / 4 of the pin area, θ can be approximated by simulation. Since the bent part of the pin is a rounded corner, the actual effective contact length is less than the theoretical length. Here, the horizontal length of the pin minus the pin thickness is used as the length for calculating the contact area, that is, 4.3-0.2=4.1mm, so the pin area is S=4.1×0.4=1.64mm, and the 3 / 4 contact area is S'=1.64×3 / 4=1.23mm 2 At this time, the simulation shows that θ is between 5.22° and 5.23°, so θ=5.22° is taken. Otherwise, if it deflects upward, θ=-5.22°.

[0102] Therefore, the swing angle tolerance (i.e., the range of the pin swing angle) is θ = ±5.22°.

[0103] 3) When the pins have both center spacing changes and swing angles, the position relationship between the pins and the pads is as follows: Fig.10 The corresponding relationship between the pin spacing offset tolerance and the pin swing angle as shown in Table 1 is obtained through software simulation based on the contact area between the pin and the pad. The spacing offset tolerance / swing angle can be selected according to actual production needs:

[0104] Table 1 Correspondence between pin pitch offset tolerance and pin swing angle

[0105]

[0106]

[0107] In the above correspondence table, when the pin spacing is within the range of ±0.2 corresponding to serial number 1, it can be known that the pin swing angle value range can only be 0, that is, for each pin, when the associated pin spacing is within the range of ±0.2 and the pin angle is 0, the contact area with the pad can meet the preset welding conditions. When the pin spacing is within the range of ±0.19 corresponding to serial number 2, it can be known that the pin swing angle value range can only be within the range of ±0.27, that is, for each pin, when the associated pin spacing is within the range of ±0.19 and the pin angle is within the range of ±0.27, the contact area with the pad can meet the preset welding conditions.

[0108] After establishing the corresponding relationship between the pin pitch offset tolerance and the pin swing angle according to the preset welding conditions, the pin pitch offset tolerance and the pin swing angle, when judging whether the contact area between the reference pin and the pad on the PCB meets the preset welding conditions according to the pin pitch and the angle corresponding to the reference pin, it can be determined that the pin pitch belongs to the pin pitch deviation tolerance interval contained in the corresponding relationship according to the pre-established corresponding relationship and the pin pitch corresponding to the reference pin, and then the corresponding pin swing angle value range is determined according to the pin pitch offset tolerance interval to which the pin pitch belongs. After that, it can be judged whether the angle corresponding to the reference pin is within the corresponding pin swing angle value range. If so, it is determined that the contact area between the reference pin and the pad meets the preset welding conditions. If not, it is determined that the base area of ​​the reference pin and the pad does not meet the preset welding conditions.

[0109] By pre-establishing the corresponding relationship between the pin spacing offset tolerance and the pin swing angle, it is possible to automatically, quickly, efficiently and accurately judge whether the contact area between the pin and the pad meets the preset welding conditions, thereby improving the efficiency and accuracy of dimensional defect judgment.

[0110] See also Fig.11 , which shows Figure 3 Another view of the TO package chip size detection method provided by the embodiment of the present application may also include:

[0111] When the pin is bent in an L-shape, a point is taken on the second surface of the bent portion of each pin, and a second line segment corresponding to each pin is generated by fitting; a point is taken on the second surface of the unbent portion of each pin, and a third line segment corresponding to each pin is generated by fitting; the angle between the second line segment and the third line segment corresponding to the pin is measured to obtain the first bending angle of the pin; the second surface of the bent portion is a surface of the bent portion parallel to the surface used to fit with the pad, and the second surface of the unbent portion is a surface of the unbent portion adjacent to the second surface of the bent portion;

[0112] When the pin is V-shaped bent, a point is taken on the second surface of the first bent portion of each pin, and a fourth line segment corresponding to each pin is generated by fitting; a point is taken on the second surface of the second bent portion of each pin, and a fifth line segment corresponding to each pin is generated by fitting; the angle between the fourth line segment and the fifth line segment corresponding to the pin, and the angle between the third line segment and the fifth line segment are measured to obtain the second bending angle and the third bending angle of the pin accordingly; the first bent portion is adjacent to the second bent portion and the first bent portion is used to fit with the soldering pad of the PCB, the second bent portion is adjacent to the unbent portion, the second surface of the first bent portion is a surface parallel to the surface of the first bent portion and the surface used to fit with the soldering pad, and the second surface of the second bent portion is adjacent to the second surface of the first bent portion.

[0113] In the present application, considering that the angle dimension of the pins in the TO packaged chip after bending is too large or too small, it will cause coplanarity error between the patch surface and the pad of the TO packaged chip, thus causing cold solder joints. For this reason, the present application can also detect the angle dimension of the pins in the TO packaged chip after bending, so as to improve the diversification of the TO packaged chip pin size detection, enhance the comprehensiveness of the TO packaged chip pin size detection, and thereby improve the accuracy of determining the TO packaged chip pin size defects.

[0114] In addition, considering that the bending conditions of the L-shaped bend and the V-shaped bend are different, corresponding bending angle dimension detection methods are used to detect the L-shaped bend and the V-shaped bend respectively.

[0115] Specifically, when the pin is L-shaped, a point can be taken on the second surface of the bent portion of the pin, and a second line segment corresponding to each pin can be generated by corresponding fitting, wherein the second surface of the bent portion is a surface parallel to the surface of the bent portion for the pad to fit. Fig.11 In the schematic diagram shown, the left surface of the bent portion is the surface for bonding the pad, and the right surface of the bent portion is the second surface of the bent portion. In addition, points are taken on the second surface of the unbent portion of each pin, and the third line segments corresponding to each pin are generated by fitting. Among them, the second surface of the unbent portion is the surface of the unbent portion adjacent to the second surface of the bent portion. Fig.11 In the schematic diagram shown, the second surface of the unbent portion is the upper surface of the unbent portion. Afterwards, for each pin, the angle between the second line segment and the third line segment corresponding to the pin can be measured to obtain the first bending angle of the pin, that is, the angle between the bent portion and the unbent portion of the pin. Fig.11 Taking the schematic diagram shown as an example, the first upper bending angle θ1 and the first lower bending angle θ2 can be detected.

[0116] When the pin is V-shaped, since the bent portion of the pin has two bent portions, namely the first bent portion and the second bent portion, the bending angle detection can be performed separately. Among them, the second bent portion of the pin is adjacent to the unbent portion of the pin, the first bent portion of the pin is connected to the second portion of the pin, and the first bent portion of the pin is far away from the unbent portion of the pin, and the first bent portion is used to fit with the pad on the PCB. For V-shaped bending, points can be taken on the second surface of the first bent portion of each pin and fitted to generate the fourth item segment corresponding to each pin. Among them, the second surface of the first bent portion is a surface parallel to the surface in the first bent portion and used to fit with the pad. In addition, points are taken on the second surface of the second bent portion of each pin and fitted to generate the fifth line segment corresponding to each pin, wherein the second surface of the second bent portion is adjacent to the second surface of the first bent portion. Afterwards, the angle between the fourth line segment and the fifth line segment corresponding to the pin can be measured to obtain the second bending angle of the pin, that is, the bending angle between the first bending portion and the second bending portion of the pin is obtained. Furthermore, the angle between the third line segment and the fifth line segment corresponding to the pin can be measured to obtain the third bending angle of the pin, that is, the bending angle between the unbent portion and the second bent portion of the pin.

[0117] From the above, it can be seen that the present application adopts the method of taking points on the surface to fit and generate line segments for bending angle detection. The point taking is relatively simple and easy, and the detection result is relatively accurate, thereby improving the accuracy of defective product screening. After the bending angle of the pin is detected, relevant personnel can determine whether the bending angle of the pin is within a reasonable range. If so, it is confirmed that there is no size defect in the bending angle of the pin.

[0118] It should be noted that since the viewing angle of the bending angle size detection is different from that of the pin spacing and the angle between pins, in order to improve the efficiency of TO package chip size detection, when the first camera is used to detect the pin spacing and the angle between pins, the bending angle size can be realized by the second camera. Of course, in order to reduce the detection cost, the first camera can also be used for implementation. In addition, considering that the deviation at the end of the bent part of the pin will be more serious, when taking points to fit the second and fourth line segments corresponding to the pin, the line segments can be generated by taking points to fit the end of the corresponding surface of the pin and measuring them.

[0119] A TO package chip size detection method provided in an embodiment of the present application may also include:

[0120] A point is taken on the first surface of the unbent portion of each pin, and a sixth line segment corresponding to each pin is generated by fitting; the first surface of the unbent portion is opposite to the second surface of the unbent portion;

[0121] Generate a pin centerline corresponding to the pin according to the third line segment and the sixth line segment corresponding to the pin, take points on the second surface of the plastic package body and fit to generate a line segment corresponding to the plastic package body, and measure the angle between the line segment corresponding to the plastic package body and the pin centerline corresponding to the pin; the second surface of the plastic package body and the second surface of the unbent portion of the pin are located on the same side;

[0122] A point is taken on the joint surface of the plastic package body and the pin to generate a vertical line, and the intersection point of the vertical line and the pin center line corresponding to the pin is obtained, and the intersection point is used as the intersection point of the vertical center line corresponding to the pin;

[0123] When the pin is bent in an L-shape, the distance between the intersection of the vertical midlines corresponding to the pin and the second line segment corresponding to the pin is measured to obtain the length of the unbent portion of the pin.

[0124] In the present application, the angle between the plastic package and the pins in the TO packaged chip and the length L of the unbent part of each pin can also be detected to achieve dimensional detection of the TO packaged chip from multiple dimensions, thereby improving the diversity of dimensional detection and further improving the accuracy of determining dimensional defects of the TO packaged chip.

[0125] Specifically, a point can be taken on the first surface of the unbent portion of each pin, and a sixth line segment corresponding to each pin can be generated by fitting according to the taken point. The first surface of the unbent portion is opposite to the second surface of the unbent portion. Fig.11 In the view shown in FIG. 1 , the first surface of the unbent portion is the lower surface of the unbent portion. Afterwards, the pin centerline corresponding to the pin can be calculated based on the third line segment corresponding to the pin and the sixth line segment corresponding to the pin. In addition, points can be taken on the second surface of the plastic package and fitted to generate the line segment corresponding to the plastic package, wherein the second surface of the plastic package and the second surface of the unbent portion of the pin are located on the same side, so that Fig.11 In the view shown, the second surface of the plastic package is the upper surface of the plastic package. The first surface of the plastic package can be fitted with a fixture. Then, the angle between the line segment corresponding to the plastic package and the pin centerline corresponding to the pin can be measured to obtain the angle between the pin and the plastic package. The angle between the pin and the plastic package is measured to prevent the TO package chip from colliding during transportation, causing the pin and the plastic package to bend at the junction, which may cause dimensional defects in the TO package pin.

[0126] For the measurement of the length of the unbent portion of the pin, a point can be taken on the joint surface of the plastic package and the pin and a vertical line perpendicular to the pin centerline corresponding to the pin can be fitted. Afterwards, the intersection of the vertical line and the pin centerline corresponding to the pin can be obtained, and the intersection can be used as the vertical centerline intersection corresponding to the pin (i.e., the intersection of the vertical line and the pin centerline). When the pin is L-shaped, the distance between the vertical centerline intersection corresponding to the pin and the second line segment corresponding to the pin (i.e., the length of the vertical line segment) can be measured to obtain the length of the unbent portion of the pin. When the pin is V-shaped, since the bending angle between the second bending portion of the pin and the unbent portion is not a right angle, it is not easy to generate a line segment perpendicular to the unbent portion at the second bending portion by taking a point on the surface. Therefore, the length of the unbent portion can be measured without using a method similar to the L-shaped bending, but can be calculated by measuring the angle between the third line segment corresponding to the pin and the fifth line segment corresponding to the pin, the length of the fifth line segment, and the length of the vertical centerline intersection to the fourth line segment to obtain the length of the unbent portion of the pin, or it can also be achieved by other methods.

[0127] Among them, since the angle between the plastic package and the pin and the length of the unbent portion of each pin are measured at the same viewing angle as the bending angle measurement, the same camera (such as the second camera) can be used for implementation. In addition, the above-mentioned method of measuring the angle between the plastic package and the pin and the length of the unbent portion of the pin by fitting the surface points can improve the accuracy of the corresponding dimension detection, so that the subsequent relevant personnel can improve the accuracy of the judgment when comparing the corresponding dimension with the corresponding reasonable range to judge whether the corresponding dimension has defects.

[0128] A TO package chip size detection method provided in an embodiment of the present application may also include:

[0129] When the pin is bent in an L-shape, a point is taken on the end surface of the bent portion; when the pin is bent in a V-shape, a point is taken on the end surface of the first bent portion, and the seventh line segment corresponding to the pin is obtained by fitting;

[0130] The distance between the seventh line segment corresponding to the pin and the pin center line corresponding to the pin is measured to obtain the length of the bent portion of the pin.

[0131] In the present application, the length of the bent portion of the pin can also be detected to achieve dimensional detection from more dimensions, thereby improving the diversity of dimensional detection and further improving the accuracy of dimensional defect determination. Specifically, when the pin is bent in an L-shape, a point can be taken at the end face of the bent portion and fitted to generate the seventh line segment corresponding to the pin. When the pin is bent in a V-shape, a point can be taken at the end face of the first bent portion and fitted to generate the seventh line segment corresponding to the pin. Afterwards, the distance between the seventh line segment corresponding to the pin and the pin centerline corresponding to the pin can be measured to obtain the length of the bent portion of the pin. Fig.11As shown, for the L-shaped bend, it includes an upper bend length l1 and a lower bend length l2.

[0132] The accuracy of the dimension detection can be improved by performing point fitting on the surface to detect the length of the bent portion of the pin.

[0133] It should be noted that for the L-shaped bend, the length measured by the above method is the actual length of the bent part of the pin, while for the V-shaped bend, the length measured by the above method is the vertical length of the bent part, rather than the sum of the length of the first bent part and the actual length of the second bent part.

[0134] A TO package chip size detection method provided in an embodiment of the present application may also include:

[0135] When the pin is bent in an L-shape, a point is taken on the surface of the bent portion that fits with the pad, and an eighth line segment corresponding to the pin is generated by fitting; the distance between the eighth line segment and the second line segment is measured to obtain the single-side coplanarity of the pin;

[0136] When the pin is V-shaped bent, a point is taken on the surface of the first bent portion that fits with the pad, and a ninth line segment corresponding to the pin is generated by fitting; the distance between the ninth line segment and the fourth line segment is measured to obtain the single-sided coplanarity of the pin.

[0137] In the present application, the single-sided coplanarity of the pin can also be detected to achieve a more comprehensive size detection of the TO packaged chip. Specifically, when the pin is L-shaped, a point is taken on the surface of the bent portion that fits with the pad, and the eighth line segment corresponding to the pin is generated by fitting. Afterwards, the distance between the eighth line segment corresponding to the pin and the second line segment is measured. Specifically, the midpoint of the eighth line segment can be taken, and the length of the perpendicular line segment from the midpoint to the second line segment can be measured to obtain the single-sided coplanarity of the pin. Fig.11 As shown in the view, for the L-type bending, it includes the single-side coplanarity h1 of the upper pin and the single-side coplanarity h2 of the lower pin.

[0138] When the pin is V-bent, a point can be taken on the surface of the first bend portion that fits the pad, and the ninth line segment corresponding to the pin can be generated by fitting. After that, the distance between the ninth line segment corresponding to the pin and the fourth line segment can be measured. Specifically, the midpoint of the ninth line segment can be taken, and the length of the perpendicular line segment from the midpoint to the fourth line segment can be measured to obtain the single-side coplanarity of the pin.

[0139] From the above, it can be known that the single-sided coplanarity of the pin is the thickness of the pin. Through this measurement, it can be judged whether the pin thickness is within the corresponding reasonable range to determine whether there is a defect in the pin thickness dimension.

[0140] See also Fig.12 and Fig.13 ,in, Fig.12 Shows Figure 3 Another view of Fig.13 A TO package chip size detection method provided in an embodiment of the present application may also include:

[0141] A point is taken at the end of the third surface of the unbent portion of the pin, and a tenth line segment corresponding to each pin is generated by fitting; the third surface of the unbent portion is parallel to the first surface of the bent portion;

[0142] The distance between the tenth line segments corresponding to two adjacent pins is measured to obtain the pin spacing between the two adjacent pins.

[0143] In the present application, the pin spacing between pins can also be measured through the unbent part of the pin. The test shows that the pin spacing is the spacing between the unbent parts of the pin, so as to realize pin size detection in multiple dimensions, thereby improving the accuracy of defective product screening. Specifically, a point can be taken at the end of the third surface of the unbent part of the pin, and the tenth line segment corresponding to each pin can be generated by fitting. Among them, the third surface of the unbent part is parallel to the first surface of the bent part. Fig.12 In the illustrated view, the third surface of the unbent portion is the upper surface or the lower surface of the unbent portion, and the end of the third surface of the unbent portion is the area of ​​the third surface of the unbent portion close to the first surface of the bent portion.

[0144] After that, the distance between the tenth line segments corresponding to two adjacent pins can be measured to obtain the pin spacing between the two adjacent pins. Specifically, the midpoint of the tenth line segment corresponding to one of the two adjacent pins can be taken, and the length of the vertical line segment from the midpoint to the tenth pin corresponding to the other pin can be measured to obtain the pin spacing between the two adjacent pins. Fig.13 In the schematic diagram, d1, d2, and d3 are the spacing values ​​between the pins, corresponding to the pad positions of the PCB patch.

[0145] The above method can be used to detect the situation in which the spacing of the TO packaged chip changes due to different forces on each pin during transportation.

[0146] It should be noted that, since the angle of view for detecting the pin spacing between two adjacent pins is different from the angle of view for detecting the other dimensions mentioned above, in order to improve the detection efficiency, a third camera can be used to implement the above process. Of course, in order to save costs, all dimension detections can be implemented using the same camera (such as the first camera).

[0147] See also Figure 5 and Fig.14 ,in, Fig.14A schematic diagram showing the distribution relationship between the TO package chip and the reference plane is shown. A TO package chip size detection method provided in an embodiment of the present application may also include:

[0148] Take a point at the end of the second surface of the bent portion of the pin, measure the distance from each point to the reference plane, and calculate the average value of the distance as the distance from the bent portion corresponding to the pin to the reference plane; the second surface of the bent portion is a surface parallel to the surface of the bent portion used to fit with the pad, and the reference plane is parallel to the surface of the bent portion used to fit with the pad;

[0149] The maximum distance and the minimum distance are selected from the distances from the bending parts corresponding to the pins to the reference plane, and the coplanarity between the pins is obtained according to the maximum distance and the minimum distance.

[0150] In the present application, the coplanarity between the pins in the TO package chip can also be detected, so as to use the coplanarity between the pins to feedback the contact error between the TO package chip and the pad plane, so as to facilitate the screening of defective products and retain good products to improve the welding quality between the good products and the pad. Among them, the TO package chip with poor coplanarity may have one or more pins with a large gap between the pad, resulting in poor welding.

[0151] Specifically, a point can be taken at the end of the second surface of the bent portion of each pin, and the distance from each point in each pin to the reference plane can be measured, and the average value of the distance in each pin can be calculated, and the average value of the distance corresponding to each pin can be used as the distance from the bent portion corresponding to each pin to the reference plane. The second surface of the bent portion is the surface of the bent portion that is parallel to the surface that fits with the pad. Figure 5 In the view shown, the second surface is the surface indicated by the rectangular frame connected to the plastic package body, the end of the second surface can be the area framed by the dotted frame, and the reference plane is parallel to the surface of the bent portion used to fit with the pad, that is, the reference plane is parallel to the pad plane. Since the farther away from the bent portion, the greater the deformation of the pins, the greater the coplanarity deviation between the pins, therefore, taking a point at the end of the second surface of the bent portion can improve the accuracy of the coplanarity calculation.

[0152] After obtaining the distances from the bending parts corresponding to each pin to the reference plane, the maximum distance and the minimum distance can be selected from these distances, and the maximum distance and the minimum distance are subtracted to obtain the coplanarity between the pins, where: Fig.14 The p in the figure is the coplanarity. After the coplanarity between the pins is automatically measured, the coplanarity between the pins can be displayed so that relevant personnel can determine whether the coplanarity between the pins is within the corresponding reasonable range, thereby determining whether the TO package chip is a defective product.

[0153] It should be noted that, in order to improve the detection efficiency, the fourth camera can be used to detect the coplanarity between the pins. Of course, in order to save costs, all size detections can be implemented using the same camera (such as the first camera).

[0154] The present application also provides a TO package chip size detection system, which may include:

[0155] The first camera is used to take a point at the end of the first surface of the bending part of each pin, and fit to generate a first line segment corresponding to each pin; the first surface of the bending part is a surface in the bending part that is perpendicular to the end face of the bending part and the surface of the bending part used to fit with the pad on the PCB; measure the distance between the first line segments corresponding to the pins located on the same side of the plastic package to obtain the pin spacing between the corresponding pins; select a reference pin from multiple pins, and detect the angle between the first line segments corresponding to the remaining pins and the first line segment corresponding to the reference pin to obtain the angle between the corresponding pin and the reference pin.

[0156] A TO package chip size detection system provided in an embodiment of the present application may also include a processor, which is used to, after obtaining the angle between the reference pin and the corresponding pin, take each pin as a reference pin, and obtain the pin spacing and the angle between the pins corresponding to the reference pin from the detected pin spacing and the angle between the pins; and determine whether the contact area between the reference pin and the pad on the PCB meets the preset welding conditions based on the pin spacing and the angle corresponding to the reference pin.

[0157] An embodiment of the present application provides a TO package chip size detection system, in which a processor is specifically used to determine a pin swing angle value range corresponding to a reference pin based on a pre-established correspondence between a pin spacing offset tolerance and a pin swing angle, and a pin spacing corresponding to the reference pin; determine whether the angle corresponding to the reference pin is within the pin swing angle value range corresponding to the corresponding pin; if so, determine whether a contact area between the reference pin and the pad meets a preset welding condition; wherein the correspondence is established based on the preset welding condition, the pin spacing offset tolerance and the pin swing angle.

[0158] A TO package chip size detection system provided in an embodiment of the present application may also include a second camera, which is used to take points on the second surface of the bent portion of each pin when the pin is bent in an L-shape, and fit to generate a second line segment corresponding to each pin; take points on the second surface of the unbent portion of each pin, and fit to generate a third line segment corresponding to each pin; measure the angle between the second line segment and the third line segment corresponding to the pin to obtain the first bending angle of the pin; the second surface of the bent portion is a surface in the bent portion that is parallel to the surface that is used to fit with the pad, and the second surface of the unbent portion is a surface in the unbent portion that is adjacent to the second surface of the bent portion; when the pin is bent in a V-shape, at the first bending angle of each pin, Points are taken on the second surface of the second bent portion of each pin, and fourth line segments corresponding to each pin are generated by fitting; points are taken on the second surface of the second bent portion of each pin, and fifth line segments corresponding to each pin are generated by fitting; the angle between the fourth line segment and the fifth line segment, and the angle between the third line segment and the fifth line segment corresponding to the pin are measured to obtain the second bending angle and the third bending angle of the pin accordingly; the first bent portion is adjacent to the second bent portion and the first bent portion is used to fit with the soldering pad of the PCB, the second bent portion is adjacent to the unbent portion, the second surface of the first bent portion is a surface in the first bent portion that is parallel to the surface used to fit with the soldering pad, and the second surface of the second bent portion is adjacent to the second surface of the first bent portion.

[0159] The embodiment of the present application provides a TO package chip size detection system, the second camera is also used to take points on the first surface of the unbent part of each pin, and fit to generate the sixth line segment corresponding to each pin; the first surface of the unbent part is opposite to the second surface of the unbent part; the pin centerline corresponding to the pin is generated according to the third line segment and the sixth line segment corresponding to the pin, points are taken on the second surface of the plastic package body and the line segment corresponding to the plastic package body is fit to generate, and the angle between the line segment corresponding to the plastic package body and the pin centerline corresponding to the pin is measured; the second surface of the plastic package body and the second surface of the unbent part of the pin are located on the same side; points are taken on the joint surface of the plastic package body and the pin to generate a vertical line, and the intersection point of the vertical line and the pin centerline corresponding to the pin is obtained, and the intersection point is used as the intersection point of the vertical centerline corresponding to the pin; when the pin is L-shaped bent, the distance between the intersection point of the vertical centerline corresponding to the pin and the second line segment corresponding to the pin is measured to obtain the length of the unbent part of the pin.

[0160] A TO package chip size detection system provided in an embodiment of the present application, the second camera is also used to take points on the end face of the bent part when the pin is bent in an L shape, and to take points on the end face of the first bent part when the pin is bent in a V shape, and to fit the seventh line segment corresponding to the pin; measure the distance between the seventh line segment corresponding to the pin and the pin centerline corresponding to the pin to obtain the length of the bent part of the pin.

[0161] A TO package chip size detection system provided in an embodiment of the present application, the second camera is also used to take points on the surface of the bent portion for fitting with the pad when the pin is bent in an L-shape, and to fit and generate an eighth line segment corresponding to the pin; measure the distance between the eighth line segment and the second line segment to obtain the unilateral coplanarity of the pin; when the pin is bent in a V-shape, take points on the surface of the first bent portion for fitting with the pad, and to fit and generate a ninth line segment corresponding to the pin; measure the distance between the ninth line segment and the fourth line segment to obtain the unilateral coplanarity of the pin.

[0162] A TO package chip size detection system provided in an embodiment of the present application may also include a third camera, which is used to take a point at the end of the third surface of the unbent part of the pin, and fit to generate a tenth line segment corresponding to each pin; the third surface of the unbent part is parallel to the first surface of the bent part; and the distance between the tenth line segments corresponding to two adjacent pins is measured to obtain the pin spacing between the two adjacent pins.

[0163] A TO package chip size detection system provided in an embodiment of the present application may also include a fourth camera, which is used to take points at the end of the second surface of the bent portion of the pin, measure the distance from each point to the reference plane, and calculate the average value of the distance as the distance from the bent portion corresponding to the pin to the reference plane; the second surface of the bent portion is a surface parallel to the surface of the bent portion used to fit with the pad, and the reference plane is parallel to the surface of the bent portion used to fit with the pad; the maximum distance and the minimum distance are selected from the distances from the bent portion corresponding to the pin to the reference plane, and the coplanarity between the pins is obtained based on the maximum distance and the minimum distance.

[0164] The description of the relevant parts of a TO package chip size detection system provided in the present application can be found in the detailed description of the corresponding parts in a TO package chip size detection method provided in an embodiment of the present application, and will not be repeated here.

[0165] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the term "include", "comprise" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment that includes a series of elements are inherent to the elements. In the absence of more restrictions, the elements limited by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or equipment that includes the elements. In addition, the above-mentioned technical solution provided in the embodiment of the present application is consistent with the corresponding technical solution in the prior art in principle, and the part is not described in detail, so as not to repeat too much.

[0166] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A TO package chip size detection method, characterized in that: The TO package chip includes a plastic package body and a plurality of pins, each of the pins includes an unbent portion and a bent portion, the unbent portion is connected to the plastic package body, and the TO package chip size detection method includes: A point is taken at the end of the first surface of the bent portion of each pin, and a first line segment corresponding to each pin is generated by fitting; the first surface of the bent portion is a surface of the bent portion that is perpendicular to the end surface of the bent portion and the surface of the bent portion that is used to fit with the pad on the PCB; Measuring the distance between the first line segments corresponding to the pins located on the same side of the plastic package body to obtain the pin spacing between the corresponding pins; A reference pin is selected from the plurality of pins, and the angles between the first line segments corresponding to the remaining pins and the first line segment corresponding to the reference pin are detected to obtain the angle between the corresponding pin and the reference pin.

2. The TO package chip size detection method according to claim 1, characterized in that: After obtaining the angle between the reference pin and the corresponding pin, the method further includes: Taking each of the pins as a reference pin, respectively, obtaining the pin spacing and angle corresponding to the reference pin from the detected pin spacing and angle between the pins; According to the pin spacing and angle corresponding to the reference pin, judging whether the contact area between the reference pin and the pad on the PCB meets the preset welding condition; If not, it is determined that the pins of the TO packaged chip have size defects.

3. The TO package chip size detection method according to claim 2, characterized in that: Judging whether the contact area between the reference pin and the pad on the PCB meets a preset welding condition according to the pin spacing and the angle corresponding to the reference pin, includes: Determine the pin swing angle value range corresponding to the reference pin according to the pre-established correspondence relationship between the pin spacing offset tolerance and the pin swing angle and the pin spacing corresponding to the reference pin; Determine whether the angle corresponding to the reference pin is within the corresponding pin swing angle value range; If so, determining that the contact area between the reference pin and the pad satisfies the preset welding condition; Wherein, the corresponding relationship is established according to the preset welding conditions, the pin spacing offset tolerance and the pin swing angle.

4. The TO package chip size detection method according to claim 1, characterized in that: Also includes: When the pins are bent in an L-shape, points are taken on the second surface of the bent portion of each pin, and second line segments corresponding to each pin are generated by fitting; Points are taken on the second surface of the unbent portion of each pin, and a third line segment corresponding to each pin is generated by fitting; the angle between the second line segment and the third line segment corresponding to the pin is measured to obtain the first bending angle of the pin; the second surface of the bent portion is a surface of the bent portion parallel to the surface of the bent portion for fitting with the pad, and the second surface of the unbent portion is a surface of the unbent portion adjacent to the second surface of the bent portion; When the pin is V-shaped bent, a point is taken on the second surface of the first bent portion of each pin, and a fourth line segment corresponding to each pin is generated by fitting; a point is taken on the second surface of the second bent portion of each pin, and a fifth line segment corresponding to each pin is generated by fitting; the angle between the fourth line segment and the fifth line segment corresponding to the pin, and the angle between the third line segment and the fifth line segment are measured to obtain the second bending angle and the third bending angle of the pin accordingly; the first bent portion is adjacent to the second bent portion and the first bent portion is used to fit with the soldering pad of the PCB, the second bent portion is adjacent to the unbent portion, the second surface of the first bent portion is a surface in the first bent portion that is parallel to the surface used to fit with the soldering pad, and the second surface of the second bent portion is adjacent to the second surface of the first bent portion.

5. The TO package chip size detection method according to claim 4, characterized in that: Also includes: Taking points on the first surface of the unbent portion of each pin, and fitting to generate a sixth line segment corresponding to each pin; The first surface of the unbent portion is opposite to the second surface of the unbent portion; Generate a pin centerline corresponding to the pin according to the third line segment and the sixth line segment corresponding to the pin, take points on the second surface of the plastic package body and generate the line segment corresponding to the plastic package body by fitting, measure the angle between the line segment corresponding to the plastic package body and the pin centerline corresponding to the pin to obtain the angle between the pin and the plastic package body; the second surface of the plastic package body and the second surface of the unbent portion of the pin are located on the same side; Take a point on the joint surface of the plastic package and the pin to generate a vertical line, obtain the intersection point of the vertical line and the pin center line corresponding to the pin, and use the intersection point as the intersection point of the vertical center line corresponding to the pin; When the pin is bent in an L-shape, the distance between the intersection of the vertical midlines corresponding to the pin and the second line segment corresponding to the pin is measured to obtain the length of the unbent portion of the pin.

6. The TO package chip size detection method according to claim 5, characterized in that: Also includes: When the pin is bent in an L-shape, a point is taken on the end surface of the bent portion; when the pin is bent in a V-shape, a point is taken on the end surface of the first bent portion, and a seventh line segment corresponding to the pin is obtained by fitting; The distance between the seventh line segment corresponding to the pin and the pin center line corresponding to the pin is measured to obtain the length of the bent portion of the pin.

7. The TO package chip size detection method according to claim 5, characterized in that: Also includes: When the pin is bent in an L-shape, a point is taken on the surface of the bent portion for fitting with the pad, and an eighth line segment corresponding to the pin is generated by fitting; and a distance between the eighth line segment and the second line segment is measured to obtain the single-side coplanarity of the pin; When the pin is bent in a V-shape, a point is taken on the surface of the first bent portion that is fitted with the pad, and a ninth line segment corresponding to the pin is generated by fitting; the distance between the ninth line segment and the fourth line segment is measured to obtain the single-sided coplanarity of the pin.

8. The TO package chip size detection method according to claim 1, characterized in that: Also includes: Taking a point at the end of the third surface of the unbent portion of the pin, and fitting to generate a tenth line segment corresponding to each of the pins; The third surface of the unbent portion is parallel to the first surface of the bent portion; The distance between the tenth line segments corresponding to two adjacent pins is measured to obtain the pin spacing between the two adjacent pins.

9. The TO package chip size detection method according to claim 1, characterized in that: Also includes: Points are taken at the end of the second surface of the bent portion of the pin, and the distances from each point to the reference plane are measured, and the average value of the distances is calculated as the distance from the bent portion corresponding to the pin to the reference plane; the second surface of the bent portion is a surface parallel to the surface of the bent portion used to fit with the pad, and the reference plane is parallel to the surface of the bent portion used to fit with the pad; A maximum distance and a minimum distance are selected from the distances from the bent portions corresponding to the pins to the reference plane, and the coplanarity between the pins is obtained according to the maximum distance and the minimum distance.

10. A TO package chip size detection system, characterized in that: include: A first camera is used to take a point at an end of the first surface of the bent portion of each of the pins, and to fit and generate a first line segment corresponding to each of the pins; The first surface of the bent portion is a surface of the bent portion that is perpendicular to the end surface of the bent portion and the surface of the bent portion used to fit with the pad on the PCB; the distance between the first line segments corresponding to the pins located on the same side of the plastic package is measured to obtain the pin spacing between the corresponding pins; a reference pin is selected from the multiple pins, and the angle between the first line segments corresponding to the remaining pins and the first line segment corresponding to the reference pin is detected to obtain the angle between the corresponding pin and the reference pin.

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