CN1581457A - Ball-grating array semiconductor device quality detecting system based on dual-eye machine vision - Google Patents

Abstract

Translated fromChinese

一种基于双目机器视觉的球栅阵列半导体器件品质检测系统，由光学成像和图像采集两部分组成，被测球栅阵列半导体器件放置在载物台上，两个CCD摄像机分别设置在光学显微镜的正上方和被测器件侧面，每一个CCD摄像机配置一套光源，两个CCD摄像机多角度采集的半导体器件图像信息，通过高速图像采集卡传送到计算机，经处理后得到器件检测需要的各项数据，进行器件的品质的评定。本发明采用软件信号触发控制图像采集、双CCD摄像机和彩色图像处理技术，实现对球栅阵列半导体器件品质的高速、高分辨率无损伤检测，满足在线实时检测的需要。

A BGA semiconductor device quality inspection system based on binocular machine vision. It consists of two parts: optical imaging and image acquisition. The BGA semiconductor device to be tested is placed on the stage, and two CCD cameras are respectively set on the optical microscope. Directly above and on the side of the device under test, each CCD camera is equipped with a set of light sources, and the image information of the semiconductor device collected by the two CCD cameras from multiple angles is transmitted to the computer through a high-speed image acquisition card, and after processing, various items required for device detection are obtained. data to evaluate the quality of the device. The invention adopts software signal trigger control image acquisition, dual CCD cameras and color image processing technology to realize high-speed, high-resolution non-destructive detection of the quality of ball grid array semiconductor devices and meet the needs of online real-time detection.

Description

Translated fromChinese

基于双目机器视觉的球栅阵列半导体器件品质检测系统BGA semiconductor device quality inspection system based on binocular machine vision

技术领域technical field

本发明涉及一种基于双目机器视觉的球栅阵列(Ball Grid Array，BGA)半导体器件品质检测系统，采用软件触发信号控制图像采集，双CCD摄像机多角度捕捉和彩色图像处理技术，实现对球栅阵列半导体器件品质的高速、高分辨率无损检测，属于自动光学检测领域。The present invention relates to a ball grid array (BGA) semiconductor device quality inspection system based on binocular machine vision, which adopts software trigger signal to control image acquisition, double CCD camera multi-angle capture and color image processing technology to realize ball grid array The high-speed, high-resolution non-destructive testing of grid array semiconductor device quality belongs to the field of automatic optical testing.

背景技术Background technique

我国是芯片制造大国，但具有自主知识产权的核心技术很少，很多电子制造设备和检测设备均是国外进口。造成这种局面的原因在于微电子制造是高技术产业，而我国在电子制造方面起步晚，科研资金和条件缺乏。自20世纪90年代中期开始，球栅阵列半导体器件因为具有引线间距大，高密度的I/O接口，自对准特性高，优良的电气性能等优点，发展相当迅速。为了控制产品质量，在球栅阵列半导体器件贴装到印制电路板之前，需要对如下指标进行检测：封装组件的可靠性；与印刷电路板的热匹配性；焊料球的共面性；对热、湿气的敏感性等。需要指出的是，球栅阵列基板上的焊球无论是通过高温焊球(90Pb/10Sn)转换，还是采用球射工艺形成，焊球都有可能出现丢失、成形过大或过小、焊料桥接、缺损等缺陷。因此，在进行表面贴装之前，需对其中的一些指标进行检测。对焊球有可能出现的丢失、成形过大或过小、焊料桥接、缺损等缺陷，以及焊料球的共面性的检测，有人提出采用激光线结构光传感器结合数字图像处理技术来进行检测。不过基于线结构光的系统在技术上主要存在以下问题：检测速度慢；需要专门马达驱动放置器件的工作台；工作台的震动易带来测量误差等。美国发明专利(专利号6,134,013)公开了一种“Optical ball grid array inspection system(球栅阵列芯片光学检测系统)”，采用平行光照射被测器件，通过测定反射光线与已知轴的角度，来计算反射面的位置信息。其主要缺陷是光学设计复杂，检测速度不高。my country is a big chip manufacturing country, but there are few core technologies with independent intellectual property rights, and many electronic manufacturing equipment and testing equipment are imported from abroad. The reason for this situation is that microelectronics manufacturing is a high-tech industry, while our country started late in electronic manufacturing and lacks scientific research funds and conditions. Since the mid-1990s, ball grid array semiconductor devices have developed rapidly because of their advantages such as large lead spacing, high-density I/O interfaces, high self-alignment characteristics, and excellent electrical performance. In order to control product quality, before the ball grid array semiconductor device is mounted on the printed circuit board, the following indicators need to be tested: the reliability of the package assembly; the thermal matching with the printed circuit board; the coplanarity of the solder balls; Sensitivity to heat, moisture, etc. It should be pointed out that whether the solder balls on the ball grid array substrate are converted by high-temperature solder balls (90Pb/10Sn) or formed by the ball-shot process, the solder balls may be lost, formed too large or too small, and solder bridging , defects and other defects. Therefore, some of these indicators need to be tested before surface mounting. For the possible defects such as missing solder balls, oversized or undersized solder balls, solder bridges, and defects, as well as the coplanarity of solder balls, some people propose to use laser line structured light sensors combined with digital image processing technology for detection. However, the system based on line structured light mainly has the following technical problems: the detection speed is slow; a special motor is required to drive the workbench where the device is placed; the vibration of the workbench can easily lead to measurement errors, etc. The US invention patent (patent number 6,134,013) discloses an "Optical ball grid array inspection system (ball grid array chip optical detection system)", which uses parallel light to irradiate the device under test, and measures the angle between the reflected light and the known axis. Calculate the position information of the reflective surface. Its main defect is that the optical design is complex and the detection speed is not high.

因此有必要研制一种机构简单、检测速度快、检测精度高的系统。对现有球栅阵列半导体器件品质检测系统以及相关技术的检索，还没有发现类似于本发明用来解决上述问题的专利。Therefore, it is necessary to develop a system with simple mechanism, fast detection speed and high detection accuracy. Searching for the existing ball grid array semiconductor device quality inspection system and related technologies has not found any patents similar to the present invention to solve the above problems.

发明内容Contents of the invention

本发明的目的在于针对现有技术的不足，提出一种基于双目机器视觉的球栅阵列半导体器件品质检测系统，可以通过高分辨率的图像采集，实现对球栅阵列半导体器件品质的高速、无损检测。The purpose of the present invention is to address the deficiencies of the prior art, and propose a BGA semiconductor device quality inspection system based on binocular machine vision, which can realize high-speed, high-speed inspection of BGA semiconductor device quality through high-resolution image acquisition Non-destructive testing.

为实现这样的目的，本发明的基于双目机器视觉的球栅阵列半导体器件品质检测系统包括光学成像和图像采集两部分。光学成像系统包括光学显微镜、彩色CCD摄像机和LED红光源，所有器材放置在密封箱内以防止外界光线的干扰。被测球栅阵列半导体器件放置在载物台上，两个CCD摄像机分别从光学显微镜的正上方和被测器件侧面多角度采集半导体器件图像信息。图像采集部分包括台式计算机和图像采集卡，利用软件触发信号逐帧采集图像，通过高速图像采集卡，将图像信息传送到计算机，经处理后得到器件检测需要的各项数据，进行器件品质的评定。To achieve such a purpose, the binocular machine vision-based ball grid array semiconductor device quality inspection system of the present invention includes two parts: optical imaging and image acquisition. The optical imaging system includes an optical microscope, a color CCD camera and a red LED light source. All equipment is placed in a sealed box to prevent interference from external light. The ball grid array semiconductor device to be tested is placed on the stage, and two CCD cameras collect image information of the semiconductor device from multiple angles directly above the optical microscope and from the side of the device under test. The image acquisition part includes a desktop computer and an image acquisition card, which uses software trigger signals to acquire images frame by frame, and transmits the image information to the computer through a high-speed image acquisition card, and obtains various data required for device testing after processing, and evaluates device quality .

本发明系统的具体结构描述如下：The specific structure of the system of the present invention is described as follows:

本发明的检测系统包括光学成像和图像采集两部分，分别实现图像捕捉、处理功能。光学成像部分包括光学显微镜、彩色CCD摄像机和LED红光源。被测BGA器件放置在显微镜正下方的载物台上，一个环形LED红色光源固定在显微镜物镜的下方，照明BGA芯片。一个彩色CCD摄像机通过C型接口直接连接在显微镜上方，采集经显微镜放大的半导体器件图像信息。另一个彩色CCD摄像机安装在BGA器件的一侧上方，此侧面CCD摄像机镜头光轴与被测半导体器件平面成一定角度，大致为30～40度左右，根据被测器件尺寸而加以调节，两者之间的距离为BGA器件尺寸的20～30倍，以保证获得完整的图像而又避免失真。与此侧面CCD摄像机相对，在被测BGA器件另一侧上方配置一个环形面阵列红色LED光源，其与BGA器件的距离为器件尺寸的5～10倍，光源平面与侧面CCD光轴平行。所有器材放置在密封箱内以防止外界光线的干扰。图像采集部分包括台式计算机和图像采集卡，利用软件触发信号将上述两CCD摄像机捕捉的图像通过图像采集卡轮流采集到计算机，图像处理软件通过对图像信息的分析，得到器件检测需要的各项数据，进行器件品质的评定。The detection system of the present invention includes two parts of optical imaging and image acquisition, which respectively realize the functions of image capturing and processing. The optical imaging part includes optical microscope, color CCD camera and LED red light source. The BGA device to be tested is placed on the stage directly under the microscope, and a ring-shaped LED red light source is fixed under the objective lens of the microscope to illuminate the BGA chip. A color CCD camera is directly connected above the microscope through a C-type interface to collect image information of semiconductor devices enlarged by the microscope. Another color CCD camera is installed above one side of the BGA device. The optical axis of the side CCD camera lens forms a certain angle with the plane of the semiconductor device under test, which is about 30 to 40 degrees. It is adjusted according to the size of the device under test. The distance between them is 20 to 30 times the size of the BGA device to ensure a complete image without distortion. Opposite to this side CCD camera, an annular surface array red LED light source is arranged on the other side of the BGA device under test, the distance between it and the BGA device is 5-10 times of the device size, and the plane of the light source is parallel to the optical axis of the side CCD. All equipment is placed in a sealed box to prevent the interference of external light. The image acquisition part includes a desktop computer and an image acquisition card. Using the software trigger signal, the images captured by the above two CCD cameras are collected to the computer in turn through the image acquisition card. The image processing software analyzes the image information to obtain various data required for device detection. , to evaluate the quality of the device.

本发明的光学成像部分安装在密封箱体内，以避免外界光线的影响，同时保持器材的干净。密封箱内壁为白色，底部为黑色漫反射材料，使得底部光线反射尽可能的均匀，以最大限度消除由此引起的干扰。The optical imaging part of the present invention is installed in a sealed box to avoid the influence of external light while keeping the equipment clean. The inner wall of the sealed box is white, and the bottom is made of black diffuse reflection material, so that the light reflection at the bottom is as uniform as possible to eliminate the interference caused by it to the greatest extent.

本发明的系统为每一个CCD摄像机配置一套光源设备。当上方CCD摄像机捕捉图像时，关闭侧面LED光源，打开固定在显微镜物镜正下方的环状LED红光源，扩散的光线以低角度均匀地照射在被测半导体器件表面上，为正上方的CCD摄像机提供光照。而当侧面CCD摄像机捕捉图像时，打开侧面LED光源，关闭固定在显微镜上的LED光源。两套CCD摄像机和光源轮流作业，互相独立。The system of the present invention configures a set of light source equipment for each CCD camera. When the upper CCD camera captures the image, turn off the side LED light source, turn on the ring-shaped LED red light source fixed directly under the microscope objective lens, and the diffused light irradiates evenly on the surface of the semiconductor device under test at a low angle, which is the CCD camera directly above Provide light. And when the side CCD camera captures images, turn on the side LED light source and turn off the LED light source fixed on the microscope. Two sets of CCD cameras and light sources work in turn and are independent of each other.

系统进行焊球高度测量的工作原理为：首先根据球栅阵列半导体器件的尺寸和测量高度的要求，由光学成像原理和几何关系确定侧面CCD摄像机安装的极限角度，以此为基准，对安装角度进行微调。原则是安装角度尽可能的接近极限角度，又能得到每一排焊球的高度信息。确定安装角度以后，进行系统标定。将侧面CCD捕捉图像信息进行分析，由标定参数和图像与空间被测器件的几何对应关系即可得焊球的高度信息。The working principle of the system for solder ball height measurement is as follows: firstly, according to the size of the ball grid array semiconductor device and the measurement height requirements, the limit angle of the side CCD camera installation is determined by the optical imaging principle and geometric relationship, and based on this, the installation angle Make minor adjustments. The principle is that the installation angle is as close to the limit angle as possible, and the height information of each row of solder balls can be obtained. After determining the installation angle, perform system calibration. The image information captured by the side CCD is analyzed, and the height information of the solder ball can be obtained from the calibration parameters and the geometric correspondence between the image and the device under test in space.

采用本发明的效果是：能准确有效地检验球栅阵列半导体器件的品质。通过采用双CCD摄像机多角度采集方法，全方位捕捉器件的图像信息。经过对顶部CCD摄像机所采集图像的处理，可以获取器件上焊球的大小、形状、位置、间距等信息。经过对侧面CCD采集图像的处理，通过几何换算，可以从图像的二维信息中得到各个焊料球的高度信息，对焊料球的共面性进行评定。根据被测器件的尺寸，精确地确定侧面CCD摄像机的安装角度，实现对每个焊球高度的检测。本系统为每个CCD摄像机提供独立的光源，采用合理的光源配置，可以得到清晰的图像，适合图像预处理。系统采用软件触发方式，控制图像抓取，也可以通过外部电平触发信号控制摄像头抓取图像。本系统采用高分辨率(1024×1024)的图像采集，可以满足球栅阵列半导体器件品质的检测要求。The effect of adopting the invention is that the quality of the ball grid array semiconductor device can be accurately and effectively inspected. Through the multi-angle acquisition method of dual CCD cameras, the image information of the device is captured in all directions. After processing the image collected by the top CCD camera, the size, shape, position, spacing and other information of the solder balls on the device can be obtained. After processing the image collected by the side CCD, through geometric conversion, the height information of each solder ball can be obtained from the two-dimensional information of the image, and the coplanarity of the solder ball can be evaluated. According to the size of the device under test, the installation angle of the side CCD camera is accurately determined to realize the detection of the height of each solder ball. This system provides an independent light source for each CCD camera. With a reasonable light source configuration, clear images can be obtained, which is suitable for image preprocessing. The system adopts software trigger mode to control image capture, and can also control the camera to capture images through external level trigger signals. This system adopts high-resolution (1024×1024) image acquisition, which can meet the quality inspection requirements of ball grid array semiconductor devices.

附图说明Description of drawings

图1为本发明球栅阵列半导体器件品质检测系统的整体结构示意图。FIG. 1 is a schematic diagram of the overall structure of the ball grid array semiconductor device quality inspection system of the present invention.

图中，1为正上方CCD摄像机，2为光学显微镜，3为正上方LED红光源，4为侧面LED红光源，5为显微镜载物台，7为被测器件，8为侧面CCD摄像机，9为CCD固定旋钮，10为上下调节旋钮，11为支架，12为密封箱，13为整套光学成像系统，14为图像采集卡，15为整套图像采集系统，16为图像处理单元。In the figure, 1 is the CCD camera directly above, 2 is the optical microscope, 3 is the LED red light source directly above, 4 is the side LED red light source, 5 is the microscope stage, 7 is the device under test, 8 is the side CCD camera, 9 CCD fixed knob, 10 up and down adjustment knob, 11 bracket, 12 sealed box, 13 complete optical imaging system, 14 image acquisition card, 15 complete image acquisition system, 16 image processing unit.

具体实施方式Detailed ways

以下结合附图对本发明的技术方案作进一步描述。The technical solution of the present invention will be further described below in conjunction with the accompanying drawings.

本发明的系统整体结构如图1所示，由光学成像系统13和图像采集系统15两部分组成。The overall structure of the system of the present invention is shown in FIG. 1 , which consists of two parts: an optical imaging system 13 and an image acquisition system 15 .

光学成像系统13包括正上方CCD摄像机1，光学显微镜2，LED红光源3，侧面LED红光源4，载物台5，侧面CCD摄像机8，CCD固定旋钮9，上下调节旋钮10，支架11，密封箱12，所有器件放置在密封箱12内，以防止外界光线的干扰。被测BGA器件7放置在光学显微镜2正下方的载物台5上，一个环形LED红色光源3固定在显微镜2物镜的下方，照明被测BGA器件7。一个彩色CCD摄像机1通过C型摄像接口直接安装在光学显微镜2的上方，采集经显微镜放大的半导体器件图像信息。另一个彩色CCD摄像机8安装在被测BGA器件7右侧的支架11上，CCD摄像机8的镜头光轴与被测器件7平面成一定角度，大致为30～40度，确切的角度随被测器件尺寸变化而加以调整。摄像机8可以通过调节旋钮10上下调节，支架11上刻有高度信息，精确到毫米。通过调节旋钮10上的指示针，可以得到CCD摄像机8的高度信息。固定旋钮9将CCD摄像机8固定在支架11上，同时可以使得CCD摄像机8在垂直平面内转动，调整角度。侧面摄像机8和被测器件7保持一定的距离，大致为器件尺寸的20～30倍，以保证获得完整图像而又避免失真。与侧面CCD摄像机8相对，在被测BGA器件7的左侧上方配置一个环形面阵列红色LED光源4，其与BGA器件7的距离为器件尺寸的5～10倍，光源平面与侧面CCD摄像机8的光轴平行。Optical imaging system 13 includes CCD camera 1 directly above, optical microscope 2, LED red light source 3, side LED red light source 4, stage 5, side CCD camera 8, CCD fixing knob 9, up and down adjustment knob 10, bracket 11, sealing Box 12, all devices are placed in the sealed box 12 to prevent the interference of external light. The BGA device 7 to be tested is placed on the stage 5 directly below the optical microscope 2 , and a ring-shaped LED red light source 3 is fixed under the objective lens of the microscope 2 to illuminate the BGA device 7 to be tested. A color CCD camera 1 is installed directly above the optical microscope 2 through a C-type camera interface to collect image information of semiconductor devices enlarged by the microscope. Another color CCD camera 8 is installed on the bracket 11 on the right side of the tested BGA device 7. The optical axis of the lens of the CCD camera 8 forms a certain angle with the plane of the tested device 7, which is roughly 30-40 degrees. The exact angle varies with the measured device 7. Adjusted for device size changes. The camera 8 can be adjusted up and down through the adjustment knob 10, and the height information is engraved on the bracket 11, accurate to millimeters. By adjusting the indicator needle on the knob 10, the height information of the CCD camera 8 can be obtained. The fixing knob 9 fixes the CCD camera 8 on the support 11, and at the same time can make the CCD camera 8 rotate in the vertical plane to adjust the angle. A certain distance is kept between the side camera 8 and the device under test 7, which is roughly 20 to 30 times the size of the device, so as to ensure a complete image without distortion. Opposite to the side CCD camera 8, an annular surface array red LED light source 4 is arranged on the upper left side of the tested BGA device 7, and the distance between it and the BGA device 7 is 5 to 10 times of the device size. The optical axes are parallel.

当正上方CCD摄像机1采集图像时，关闭侧面LED光源4，打开正上方的光源3。而当侧面CCD摄像机8采集图像时，关闭器件正上方的光源3，打开侧面LED光源4。本发明采用的CCD摄像机1和8可以采用彩色2/3’CCD摄像机，分辨率为1024×1024象素。采用手动调焦的镜头，焦距变化范围8-48mm。When the CCD camera 1 directly above collects images, the side LED light source 4 is turned off, and the light source 3 directly above is turned on. When the side CCD camera 8 collects images, the light source 3 directly above the device is turned off, and the side LED light source 4 is turned on. CCD camera 1 and 8 that the present invention adopts can adopt color 2/3 ' CCD camera, and resolution is 1024 * 1024 picture element. With manual focus lens, the focal length range is 8-48mm.

图像采集系统15包括台式计算机16和图像采集卡14。图像采集卡14通过数字电缆分别和两个摄像机1、8相连，先后将两摄像机采集的图像信息传递到计算机16。本发明采用软件触发信号，控制被测器件的图像抓取。图像采集系统没有严重的噪声信息，能够满足后续图像处理的需要。图像经过软件的处理，可以得到器件检测需要的各项数据，进行器件品质的评定。The image acquisition system 15 includes a desktop computer 16 and an image acquisition card 14 . The image acquisition card 14 is respectively connected to the two cameras 1 and 8 through digital cables, and transmits the image information collected by the two cameras to the computer 16 successively. The invention uses a software trigger signal to control the image capture of the device under test. The image acquisition system has no serious noise information and can meet the needs of subsequent image processing. After the image is processed by the software, various data required for device inspection can be obtained to evaluate the quality of the device.

Claims (2)

1, a kind of ball grid array semiconductor device quality detection system based on binocular machine vision, form by optical imagery and IMAQ two parts, it is characterized in that whole optics imaging moiety (13) is placed in the stuffing box (12), wherein measured device (7) is placed on the objective table (5) under the light microscope (2), an annular LED red light source (3) is fixed on the below of microscope (2) object lens, a colourful CCD video camera (1) is directly installed on the top of light microscope (2) by camera interface, the semiconductor device image information that collection is amplified through microscope, another colourful CCD video camera (8) is installed on the support (11) of measured device (7) one sides, and by the angle in fixed knob (9) the adjusting vertical plane, regulate upper-lower position by adjusting knob (10), the camera lens optical axis of side ccd video camera (8) becomes 30～40 degree angles with measured device (7) plane, distance is 20～30 times of measured device (7) size between side ccd video camera (8) and the measured device (7), relative with side ccd video camera (8), opposite side top configuration ring surface array red LED light source (4) at measured device (7), the distance of itself and measured device (7) is 5～10 times of device size, the light source plane is parallel with the optical axis of side ccd video camera (8), image pick-up card (14) in the IMAQ part by digital cable respectively with two ccd video cameras (1,8) link to each other, the image information of camera acquisition is delivered to computer (16).

2, according to the ball grid array semiconductor device quality detection system based on binocular machine vision of claim 1, it is characterized in that the inwall of described stuffing box (13) is white, the bottom is the black diffuse-reflective material.