阅读说明：本技术 一种bga锡球检测方法及系统 (BGA solder ball detection method and system ) 是由 唐坤 王广欣 相楠 马小庆 王钰森 崔文龙 孙彬 于 2021-09-18 设计创作，主要内容包括：本发明提供了一种BGA锡球检测方法及系统,涉及集成电路封装测量技术领域,旨在解决BGA锡球检测效率较低,检测结果不精准的问题,采用的技术方案是,通过多组光场相机的配合拍摄,能够对BGA锡球进行多个视角的图像信息,通过对多个视角的图像信息观察和对比,更容易发现BGA锡球表面进行检测,使检测出的信息更具有准确性,同时使检测出的结果更加稳定；至少一组光场相机与检测管在同一水平面上,可通过此组光场相机来对BGA锡球的直径和真球度进行检测,使检测结构更加准确；测管倾斜设置,可使待检测的BGA锡球依次通过检测管,提高检测效率,同时也提高对BGA锡球检测的精准性。(The invention provides a BGA solder ball detection method and a system, which relate to the technical field of integrated circuit packaging measurement and aim to solve the problems of low detection efficiency and inaccurate detection result of the BGA solder ball; the optical field cameras are arranged on the same horizontal plane with the detection tube, so that the diameter and true sphericity of the BGA solder ball can be detected through the optical field cameras, and the detection structure is more accurate; the inclination of the test tube is arranged, so that the BGA solder balls to be detected can sequentially pass through the test tube, the detection efficiency is improved, and the accuracy of BGA solder ball detection is improved.)

1. A BGA solder ball detection method comprises the following steps:

step 1, debugging the detection field and equipment of the BGA solder ball, wherein the debugging comprises the debugging of a detection tube (1), a light field camera (2), a light source (3) and analysis equipment;

step 2, the BGA solder balls to be detected sequentially pass through the detection tube (1);

step 3, collecting multi-view images of the BGA solder balls passing through the detection tube (1) through the light field camera (2);

step 4, analyzing the BGA solder ball multi-view images collected by the light field camera (2), and detecting the three-dimensional size information and the defect information of the BGA solder ball through an image;

and 5, obtaining the detection information result of the BGA solder balls.

2. The BGA solder ball testing method of claim 1, wherein: the detection tube (1) is made of transparent materials, and the detection tube (1) is obliquely arranged.

3. The BGA solder ball testing method of claim 1, wherein: the commissioning of the light field camera (2) comprises the focal length and aperture of the light field camera (2).

4. The BGA solder ball testing method of claim 3, wherein: at least one light field camera (2) is in the same plane as the detection tube (1).

5. The BGA solder ball testing method of claim 1, wherein: the light sources (3) are provided with a plurality of groups and arranged around the detection tubes (1) in an array manner.

6. The BGA solder ball testing method of claim 1, wherein: the three-dimensional size information detection comprises the diameter and the true sphericity of the BGA solder balls; the defect information detection comprises surface depressions, protrusions, air holes, scratches and fine slits.

7. The BGA solder ball testing method of claim 6, wherein: the defect information detection also comprises a Ball shear test.

8. A BGA tin ball detection system is characterized in that: the detection system comprises a detection tube (1), a light field camera (2), a light source (3) and an analysis device, wherein the light source (2) is used for detecting the illumination of a field and helping the light field camera (2) to acquire images; the light field camera (2) is used for acquiring images of BGA solder balls rolling in the inclined detection tube (1), and the analysis equipment is used for analyzing the images acquired by the light field camera (2).

9. The BGA solder ball inspection system of claim 8, wherein: the light field cameras (2) are arranged in multiple groups and are arranged on the periphery of the detection tube (1) in a staggered mode, and at least one group of light field cameras (2) and the detection tube (1) are arranged on the same horizontal plane and used for acquiring the diameter of the BGA solder ball.

10. The BGA solder ball inspection system of claim 8, wherein: the analysis equipment comprises a microprocessor, analyzes the image obtained by the light field camera (2), marks BGA solder ball data in the image and makes a detection information result.

Technical Field

The invention relates to the technical field of integrated circuit packaging measurement, in particular to a BGA solder ball detection method and a system.

Background

An integrated circuit (integrated circuit) is a type of microelectronic device or component. The transistor, the resistor, the capacitor, the inductor and other elements and wires required in a circuit are interconnected together by adopting a certain process, are manufactured on a small or a plurality of small semiconductor wafers or medium substrates, and are then packaged in a tube shell to form a micro structure with the required circuit function; all the elements are structurally integrated, so that the electronic elements are greatly miniaturized, low in power consumption, intelligent and high in reliability. It is denoted by the letter "IC" in the circuit.

The location where the integrated circuit is packaged in the electronic pyramid is both the apex of the pyramid and the base of the pyramid. It is sufficient to say that it is in both positions at the same time. ICs represent the tip of electronics in terms of the density of electronic components (e.g., transistors). However, IC is a starting point and a basic structural unit, which is the basis for most electronic systems in our lives. Similarly, ICs are not just monolithic chips or basic electronic structures, but are widely varied in variety (analog, digital, radio frequency, sensors, etc.) and thus vary in packaging requirements and requirements. A full review of IC packaging techniques is provided herein, which describes in bold lines the various materials and processes used in fabricating these indispensable package structures.

With the progress of integration technology, the improvement of devices and the use of deep submicron technology in the 90 s, LSI, VLSI and ULSI have appeared in succession, the integration level of a silicon single chip has been increasing, the requirements for packaging integrated circuits have become stricter, the number of I/O pins has sharply increased, and power consumption has also increased. In order to meet the development requirement, a new variety, namely Ball Grid Array (BGA) packaging is added on the basis of the original packaging variety.

The three-dimensional measurement and defect detection technology is a core technology in the field of machine vision and measurement. Three-dimensional measurement and defect detection refers to identifying three-dimensional information and defects of an object. The measurement of three-dimensional dimension of BGA solder balls and defect detection are always one of the most difficult issues for industrial appearance detection. At present, the industrial world mostly adopts manual re-judgment after the detection of the three-dimensional dimension and the defect of the BGA solder ball by a two-dimensional camera, has advantages in the aspect of solder ball positioning, but has the defects of only judging whether the solder is at the corresponding position or not at a certain angle due to the lack of height information, and more bad phenomena under various complex conditions such as solder volume, surface roundness, foreign matters and the like are detected or depend on manual re-judgment and spot check, thereby causing serious restriction on automatic networking in electronic production.

The BGA is called Ball Grid Array (PCB) in a Ball Grid Array structure, and the method has the advantages of small packaging area; the functions are increased, and the number of pins is increased; the PCB can be centered by itself during the flux welding, and is easy to be tinned; the reliability is high; good electrical property, low overall cost and the like, and is more and more widely applied. The research on BGA solder balls in developed countries such as Europe, America, Japan and Korean is early, the research comprises ball manufacturing equipment, a ball manufacturing process and a solder ball detection method, and the research leads the development direction of the world BGA industry in the production and sale of large electronic products such as memories, CPUs (central processing units), digital signal processors and the like by virtue of technical advantages at present, and is in a global monopoly position. China still needs to rely on import of BGA solder ball products. The BGA packaging solder ball has the characteristics of small size, high precision requirement and the like, and the preparation technology and the detection technology of the solder ball are the main reasons for limiting the development of the industry. The lack of the solder ball detection can cause the defects of solder joint failure, ball jumping, cavities, solder joint deviation and the like in the ball mounting process, cause the failure of components and parts, and cause major accidents in serious cases.

In recent years, domestic BGA solder balls have been developed, but at present, domestic detection of BGA solder balls mainly depends on detection diameter, and there is no detection method, so that the yield is low.

Disclosure of Invention

In view of the problems in the prior art, the invention discloses a BGA solder ball detection method, which comprises the following steps:

step 1, debugging detection sites and equipment of BGA solder balls, including debugging detection tubes, light field cameras, light sources and analysis equipment;

step 2, the BGA solder balls to be detected sequentially pass through the detection tube, so that the BGA solder balls to be detected sequentially pass through the detection tube in a single mode, the detection efficiency is improved, the detection result of the BGA solder balls is improved, and the result is more accurate;

step 3, collecting multi-view images of the BGA solder balls passing through the detection tube through the light field camera, so that the analysis equipment can conveniently perform contrast detection on the BGA solder balls, and the accuracy of a detection result is improved;

step 4, analyzing the BGA solder ball multi-view images collected by the light field camera, and detecting the three-dimensional size information and the defect information of the BGA solder ball through the images;

and 5, obtaining the detection information result of the BGA solder balls.

As a preferable technical scheme of the invention, the detection tube is made of transparent materials, is obliquely arranged and is convenient for the light field camera to shoot the BGA solder balls passing through the detection tube.

As a preferred technical solution of the present invention, the debugging of the light field camera includes a focal length and an aperture of the light field camera, and an optical lens with a suitable focal length and magnification is selected according to a placement position of the light field camera.

As a preferred technical scheme of the invention, at least one light field camera and the detection tube are in the same plane, and image information of a plurality of visual angles is observed and compared, so that the BGA solder ball surface can be more easily found for detection, the detected information has higher accuracy, and the detected result is more stable.

According to the preferred technical scheme, the light sources are arranged in multiple groups and are arranged around the detection tube array, so that the BGA solder balls are all in the same brightness environment when the light field camera shoots the BGA solder balls, and the BGA solder ball images shot by the light field camera are clearer.

According to a preferred technical scheme, the three-dimensional size information detection comprises the diameter and the true sphericity of the BGA solder ball, the diameter of the BGA solder ball is detected, an image shot by a light field camera is used for amplifying the obtained image, a measuring tool is used for measuring the amplified image, and the diameter of the BGA solder ball can be calculated by dividing the measurement result by the amplification factor of the image; the defect information detection comprises surface depression, protrusion, air holes, scratches and fine slits, the conditions of pits, air holes, cracks and microstructures on the surface of the defect are observed through the amplification of a scanning electron microscope, and the oxygen content of the surface is tested by adopting an oxygen-nitrogen-hydrogen analyzer.

As a preferable technical scheme of the invention, the defect information detection further comprises Ball shear test, wherein the Ball shear test requires that the fracture positions of welding spots are all generated on the solder balls, and the Ball shear value exceeds 100 gf.

The invention also discloses a BGA tin ball detection system, which adopts the technical scheme that the detection system comprises a detection tube, a light field camera, a light source and analysis equipment, wherein the light source is used for detecting the illumination of a field and helping the light field camera to acquire images; the light field camera is used for acquiring images of the BGA solder balls rolling in the inclined detection tube, and the analysis equipment is used for analyzing the images acquired by the light field camera.

As a preferred technical solution of the present invention, the light field cameras are provided with a plurality of groups, and are arranged around the detection tube in a staggered manner, and at least one group of light field cameras and the detection tube are in the same horizontal plane, and are used for acquiring the diameter of the BGA solder ball.

As a preferred technical scheme of the invention, the analysis equipment comprises a microprocessor, analyzes the image obtained by the light field camera, classifies and marks BGA solder ball data in the image, and makes a detection information result.

The invention has the beneficial effects that: the BGA solder ball detection device can carry out image information of a plurality of visual angles on the BGA solder ball by matching shooting of a plurality of groups of light field cameras, and can easily find the surface of the BGA solder ball for detection by observing the image information of the plurality of visual angles and amplifying and comparing the shot image information, so that the detected information has higher accuracy and the detected result is more stable; at least one group of light field cameras and the detection tube are arranged on the same horizontal plane, the diameter and the true sphericity of the BGA solder ball can be detected through the group of light field cameras, and the detection structure is more accurate.

Furthermore, the detection tube is obliquely arranged, so that BGA solder balls to be detected can sequentially pass through the detection tube, the detection efficiency is improved, and the detection accuracy of the BGA solder balls is improved; the image shot by the light field camera is analyzed through the analysis equipment, the image can be amplified, observed and compared, the BGA solder ball is detected more thoroughly, and the error of the detection result is reduced.

Drawings

In order to more clearly illustrate the detailed description of the invention or the technical solutions in the prior art, the drawings that are needed in the detailed description of the invention or the prior art will be briefly described below. Throughout the drawings, like elements or portions are generally identified by like reference numerals. In the drawings, elements or portions are not necessarily drawn to scale.

FIG. 1 is a first schematic flow chart of the detection method of the present invention;

FIG. 2 is a schematic flow chart of a detection method according to the present invention;

FIG. 3 is a perspective view of a BGA solder ball inspection system in accordance with the present invention;

FIG. 4 is a front view of the BGA solder ball inspection system of the present invention;

FIG. 5 is a side view of the BGA solder ball inspection system of the present invention;

in the figure: 1-detection tube, 2-light field camera and 3-light source.

Detailed Description

The technical scheme of the invention is clearly and completely described in the following with reference to the accompanying drawings. In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example 1

The invention discloses a BGA solder ball detection method, which comprises the following steps:

step 1, debugging detection sites and equipment of BGA solder balls, including debugging a detection tube 1, a light field camera 2, a light source 3 and analysis equipment;

step 2, the BGA solder balls to be detected sequentially pass through the detection tube 1, the BGA solder balls to be detected can be randomly extracted from samples, and the proportion of the number of the randomly extracted BGA solder ball samples is not less than ten thousandth of the total number of the BGA solder balls;

step 3, collecting multi-view images of the BGA solder balls passing through the detection tube 1 by using the light field camera 2;

step 4, analyzing the BGA solder ball multi-view images collected by the light field camera 2, and detecting the three-dimensional size information and the defect information of the BGA solder ball through the images;

and 5, obtaining the detection information result of the BGA solder balls.

In a preferred embodiment of the present invention, the inspection tube 1 is made of a transparent material, and the inspection tube 1 is disposed in an inclined manner, so that the BGA ball can pass through the inspection tube 1 smoothly, and the true sphericity of the BGA can be observed further.

As a preferred technical solution of the present invention, the debugging of the light field camera 2 includes the focal length and aperture of the light field camera 2, and an optical lens with a suitable focal length and magnification is selected according to the placement position of the light field camera, which is specifically expressed as that the light field camera shoots a pure color calibration plate image in which the microlens array is just or close to a tangent state.

As a preferred technical solution of the present invention, at least one of the light field cameras 2 is on the same plane as the detecting tube 1, and the light field camera 2 on the same plane as the detecting tube 1 is used for detecting the diameter of the BGA solder ball.

As a preferred technical scheme of the present invention, the light sources 3 are provided with a plurality of groups, and are arranged around the detection tube 1 in an array, and the plurality of groups of light sources 3 are provided, so that when the light field camera 2 shoots the BGA solder balls, the BGA solder balls are all in an environment with the same brightness, the shooting accuracy of the light field camera 2 is increased, and meanwhile, the images shot by the light field camera 2 can be conveniently compared and analyzed by subsequent analysis equipment.

As a preferred technical scheme of the invention, the three-dimensional size information detection comprises the diameter and true sphericity of the BGA solder balls; the defect information detection comprises surface depression, protrusion, air holes, scratches and fine slits, the conditions of pits, air holes, cracks and microstructures on the surface of the defect are observed through the amplification of a scanning electron microscope, and the oxygen content of the surface is tested by adopting an oxygen-nitrogen-hydrogen analyzer.

And detecting the diameter of the BGA solder ball, amplifying the obtained image through an image shot by a light field camera, measuring the amplified image by adopting a measuring tool, and dividing the measurement result by the image amplification factor to calculate the diameter of the BGA solder ball.

The defect information detection of the BGA solder ball comprises the steps of magnifying a shot image by 50 times, observing the smoothness and the flatness of the BGA solder ball by observing the magnified image, and observing no impurities by naked eyes and simultaneously avoiding scratches, depressions, air holes and fine gaps.

As a preferable technical scheme of the invention, the defect information detection further comprises Ball shear test, wherein the Ball shear test requires that the fracture positions of welding spots are all generated on the solder balls, and the Ball shear value exceeds 100 gf.

Bond alloy Ball Shear Test (BST) is another method of evaluating gold ball bonding strength. This method is a complementary method to the pull-off test, but cannot replace the pull-off test. This is because the failure mechanism exhibited during bonding is more pronounced in the shear test and less affected in the pull test.

The invention also discloses a BGA tin ball detection system, which adopts the technical scheme that the detection system comprises a detection tube 1, a light field camera 2, a light source 3 and an analysis device, wherein the light source 2 is used for detecting the illumination of a field and helping the light field camera 2 to acquire images; the light field camera 2 is used for acquiring images of BGA solder balls rolling in the inclined detection tube 1, and the analysis equipment is used for analyzing the images acquired by the light field camera 2.

As a preferred technical solution of the present invention, the light field cameras 2 are provided with a plurality of groups, and are arranged around the detection tube 1 in a staggered manner, and at least one group of the light field cameras 2 and the detection tube 1 are in the same horizontal plane, and are used for acquiring the diameter of the BGA solder ball.

As a preferred technical scheme of the invention, the analysis equipment comprises a microprocessor, analyzes the image obtained by the light field camera 2, classifies and marks BGA solder ball data in the image, and makes a detection information result.

Components not described in detail herein are prior art.

Although the present invention has been described in detail with reference to the specific embodiments, the present invention is not limited to the above embodiments, and various changes and modifications without inventive changes may be made within the knowledge of those skilled in the art without departing from the spirit of the present invention.