CN103234977A - Double-thermal imager flip-chip soldering joint defect infrared temperature measurement detection method - Google Patents
Double-thermal imager flip-chip soldering joint defect infrared temperature measurement detection method Download PDFInfo
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- CN103234977A CN103234977A CN201310140090XA CN201310140090A CN103234977A CN 103234977 A CN103234977 A CN 103234977A CN 201310140090X A CN201310140090X A CN 201310140090XA CN 201310140090 A CN201310140090 A CN 201310140090A CN 103234977 A CN103234977 A CN 103234977A
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Abstract
The invention relates to a detection method of chip soldering joint defects, and in particular relates to a double-thermal imager flip-chip soldering joint defect infrared temperature measurement detection method, aiming at overcoming the defect that the actual production demand can not be met by the existing detection technology. The method for detecting the flip-chip soldering joint defects comprises the following steps of: arranging a thermal imager A at one side of a flip chip, and arranging a thermal imager B and an infrared laser at one side of a substrate; controlling the laser beam to be slightly smaller than bonding pads; aligning the infrared laser beam to the bonding pads to be detected on the substrate of the flip chip, adjusting the power and the pulse width parameters, and carrying out thermal excitation on the bonding pads; respectively detecting the temperature rise processes of the part of the bonding pads irradiated by a laser spot and the corresponding chip solder ball area in real time at the same time by using the thermal imager A and the thermal imager B, and observing and shooting the thermal image of the highest point of the temperature rise; and judging the flip-chip soldering joint defects according to the temperature rise curve or the thermogram. The flip-chip soldering joint pseudo soldering detection method adopts a point-by-point detection method, and has the characteristics of being free from damage, high in identification rate of the detects and visual and simple to judge.
Description
Technical field
The present invention relates to a kind of detection method of welding point defect of chip, be specifically related to a kind of detection method of upside-down mounting welding core welding point defect.
Background technology
Along with the direction of Electronic Packaging technology to high density, high-performance, miniaturization develops, BGA(Ball Grid Array) packing forms has become the main flow of contemporary Electronic Packaging.Ceramic ball grid array CBGA(CeramicBall Grid Array) as a kind of packing forms of BGA, because its high I/O density, high reliability and good electric and thermal behavior are widely used in military affairs, the Aeronautics and Astronautics electronic equipment is made the field.CCGA(Ceramic Column Grid Array) be the improvement of carrying out on the CBGA basis, it substitutes ball array by the post array, has alleviated the ceramic substrate that caused by thermal mismatching and the shear stress between PCB, has improved the thermal cycle reliability.
The microminiaturization of microelectronic interconnection solder joint and the complicacy of welding material are easy to produce defective.The welding off normal that occurs in the welding, the bad and internal porosity of welding profile, rosin joint etc. these all can butt welding point thermal fatigue life exert an influence.Studies show that electron device inefficacy 70% is because encapsulation and assembling inefficacy cause, and in the inefficacy of Electronic Packaging and assembling, the inefficacy of solder joint is main cause.In the Electronic Packaging process, it is very important that solder joint connects, and the reliability of electronic equipment often is rooted in the reliability of solder joint.Welding spot size is more and more littler, and solder joint more becomes the most weak connecting link.
Common non-contact detection method mainly contains: optical visual detects, scanning sound micro-(SAM) detects, X ray detects.
In the optical visual detection technique, the structure light 3 D vision detection technology records the 3D rendering information of chip under test by the optical triangulation method, carries out image and handles and can draw the 3D architectural feature; The optical grating projection Moire fringe interfere with different light intensity repeatedly phase-shifting technique be combined the detection technique that forms, also can carry out the measurement of 3D profile, lateral resolution reaches 7.5um, but axial repeatable accuracy reaches 2um, is suitable for the detection of metal welding zone in the substrate; The double-photon optical that is equipped with silicon solid immersion camera lens is sent a telegraph stream microscope inspection survey technology, and lateral resolution reaches 166nm, axially detects the degree of depth and reaches 100nm, is suitable for the detection of bare chip (not back bonding) inner structure.The optical visual detection method is mainly used to detect the preceding defective workmanship of FC chips welding, can detect welding point defect and coplanarity by real-time online, but is suitable for the welding point defect detection that the welding back hides.
SAM detects the inherent vice that utilization sound micro-imaging principle is come test sample.The ultrasound wave of emission ultrasonic transducer generating closes medium (deionized water) through misfortune and propagates into the sample surface, and when defective such as bubble, crackle and tomography was arranged when sample surfaces or inside, ultrasound wave was propagated and is obstructed, and has only part to see through defective and passes to the sample bottom.At the zero defect place, ultrasonic wave energy successfully propagates into the sample bottom.Through the ultrasound wave that the sample bottom reflection is returned, just different at the intensity of acoustic wave of zones of different, cause the mechanical activation amplitude of accepting ultrasonic transducer and the current amplitude difference of generation, just present different light and shades on the acoustic image and change.Just can determine the acoustic attenuation of defect area by acoustic image is handled, and then characterize out the microstructure state of sample interior, realize the detection of sample interior defective.
It is another technology commonly used in the FC chip defect detects that X ray detects.X-ray source emission X ray because different materials just produces different light and shade zones to the absorptivity difference of X ray on the receiver, forms the shadow image of sample by sample.Receiver is converted to optical imagery with the light and shade zone and has just obtained the sample interior image, and then detects sample defects.X ray detects and can be divided into the detection of direct-injection type X ray and X ray layering detection.Utilize the direct-injection type X ray to the FC chip detection, can obtain the solder joint internal characteristics, but can not distinguish vertically superposed feature.And X ray layering detection technique is got " dropping cut slice " at same solder joint differing heights, can measure solder joint amount of solder and welding spot forming situation, obtains solder joint 3D testing result, finishes most welding point defects and detects.The X ray checkout equipment is relatively more expensive, and detection time is long, and efficient is low.X ray can damage sample, can't detect rosin joint crackle situation, and human body is harmful to, and needs the operator to have strong experience.
In sum, existing detection technique can't satisfy produces actual demand, and Aero-Space and military industry field have high requirement to reliability of products, and therefore researching and developing a kind of reliable Solder Joint in Flip Chip defect detector has great realistic meaning.
Summary of the invention
At having the defective that detection technique can't satisfy the production actual demand now, the invention provides a kind of reliable upside-down mounting welding core welding point defect to looking the thermometric detection method.
The present invention detects the upside-down mounting welding core welding point defect as follows: the side at flip-chip arranges a thermal imaging system A, in substrate one side a thermal imaging system B and infrared laser are set, the laser beam diameter is slightly less than pad, infrared laser beam is aimed at flip-chip substrate pad to be measured, adjust power and pulsewidth parameter, it is imposed thermal excitation, thermal imaging system A and thermal imaging system B be difference detection laser light spot substrate pad place and the temperature rise process in chip soldered ball district in real time accordingly simultaneously, observe and take the heat picture of temperature rise peak simultaneously, judge the upside-down mounting welding core welding point defect according to temperature rise curve or thermography.
Immediate with this method is University of Science and Technology, Central China " based on the flip chip bonding defect inspection method research of active infrared thermal imaging ".Both contrasts are as can be known:
(1) LASER HEAT LOADING position difference, it is whole loading of substrate or chip, is on the one hand to the adverse effect of chip, on the other hand because whole loading causes heat transfer process complicated, it is very faint that the low heat conductivity of substrate and chip causes heat to be transmitted to effective interface again, and signal to noise ratio (S/N ratio) is extremely low.
(2) low just because of signal to noise ratio (S/N ratio), want to obtain the later stage computing that effective testing result needs heat picture is carried out complexity, not only cause efficient low, and differentiate difficulty, present laboratory conditions connects scarce this major defect of ball and still can't reliably detect.Therefore this detection method in University of Science and Technology, Central China not only is difficult to obtain effective testing result, more away from practical application still.
(3) with respect to University of Science and Technology, Central China, the method that upside-down mounting welding core solder joint rosin joint detection method of the present invention adopts pointwise to detect, some is low though look efficient, has harmless, the high discrimination power of defective, differentiates characteristic of simple directly perceived, and is specific as follows:
Harmless: this detection method only imposes laser pumping to pad, and 2 watts of laser instrument peak powers, maximum temperaturerises such as pad solder ball leads only need about 40 ℃, and other local place such as chip base is in room temperature state substantially.
High discrimination power: although the LASER HEAT excitation is very little, but be loaded into the active path of high thermal conductivity entirely, and other places such as chip and substrate only are in room temperature state, just ' lighted ' relevant circuit lead path, therefore has unprecedented high-contrast, high s/n ratio easilier obtains effective information.
Differentiate directly perceived simple: this method can take two kinds of methods to differentiate defective, and (1) major defect can directly be differentiated by the heat picture contrast, need not complicated later image computing.(2) the temperature rise curve contrast can obtain defective differentiation more accurate than thermal map even that can quantize.
The applicable craft scope is wide: the substrate side is planted the ball bonding point defect and is detected (Fig. 8) when defects detection (Fig. 7) that this method can be equally applicable to chip side when planting ball and three-dimensional assembling, and principle is the same.
Description of drawings
Fig. 1 is that welding point defect of the present invention is to looking thermometric detection method synoptic diagram;
Fig. 2 is that qualified solder joint detects synoptic diagram;
Fig. 3 is qualified solder joint temperature rise curve;
Fig. 4 is that defectiveness solder joints such as rosin joint, pore, crackle, scarce ball detect synoptic diagram;
Fig. 5 is defectiveness solder joint temperature rise curves such as rosin joint, pore, crackle, scarce ball;
Fig. 6 detects synoptic diagram for bridging defective solder joint;
Fig. 7 is bridging defective solder joint temperature rise curve;
Fig. 8 is the heat picture of soldered ball defective thermal infrared imager A when (lacking ball, big crackle);
Fig. 9 is the heat picture of soldered ball defective thermal infrared imager B when (lacking ball, big crackle);
The heat picture of thermal infrared imager A when Figure 10 is the soldered ball bridging;
The heat picture of thermal infrared imager B when Figure 11 is the soldered ball bridging;
Figure 12 plants ball process soldered ball defects detection figure for chip side;
Figure 13 plants ball process welding point defect detection figure for substrate side in the three-dimensional packaging technology.
Embodiment
Below in conjunction with accompanying drawing technical scheme of the present invention is further described; but do not limit to so; every technical solution of the present invention is made amendment or is equal to replacement, and do not break away from the spirit and scope of technical solution of the present invention, all should be encompassed in protection scope of the present invention.
As shown in Figure 1, side at flip-chip arranges a thermal imaging system B, in substrate one side a thermal imaging system A and infrared laser are set, the laser beam diameter is slightly less than pad, infrared laser beam is aimed at flip-chip substrate pad to be measured, adjust power and pulsewidth parameter, it is imposed thermal excitation, thermal imaging system A and thermal imaging system B distinguish the substrate pad place at detection laser light spot place and the temperature rise process in chip soldered ball district simultaneously in real time, observe and take the heat picture of temperature rise peak simultaneously.
Consistance in view of the accurate controlled and device of laser power pulsewidth itself, be that given heat is consistent, the heat conduction path thermal resistance also is consistent simultaneously, resulting two temperature rise curves of so similar qualified solder joint must very approach and match, suppose that substrate land side thermal imaging system maximum temperature that A surveys reaches 55 ℃, chip side thermal imaging system maximum temperature that B surveys is at 35 ℃, and the temperature difference is seen Fig. 2, Fig. 3 at 20 ℃.
For defectives such as scarce ball, rosin joint, pore, crackles, because obstruction is in various degree arranged on the heat conduction route, heat is difficult to be transmitted on the chip, its influence also can be reflected on its temperature rise curve, therefore to rise the curve maximum temperature be 60 ℃ to thermal imaging system A institute thermometric, and it is 25 ℃ that thermal imaging system B institute thermometric rises the curve maximum temperature, and both temperature difference are 35 ℃, temperature difference maximum is far above both temperature difference of qualified solder joint.See Fig. 4, Fig. 5.
For the bridging defective, because heat is conducted widening, shunting of route, be lower than qualified solder joint in the detected temperature rise curve maximum temperature of substrate one side thermal imaging system A, maximum temperature may be 40 ℃, the temperature rise curve maximum temperature that chip side thermal imaging system B measures is 30 ℃, the temperature difference is 10 ℃, and both temperature difference minimums are less than both temperature difference of qualified solder joint.See Fig. 6, Fig. 7.
When temperature near the time also can to differentiate bridging according to the difference of thermography hot zone still be rosin joint, pore, crackle, lack defective such as ball.
When defective is serious, as scarce ball, big crackle, gross blow hole, situations such as serious bridging can be judged easily by the heat picture contrast of thermal imaging system A and B.Such as: at scarce ball, big crackle, under the gross blow hole situation, heat conduction path is blocked or is approached when blocking, and the pad of base side thermal imaging system A shows as high temperature, and the chip relevant position that opposite side thermal imaging system B absorbs does not have the temperature rise phenomenon substantially, shown in Fig. 8 and 9.
When tested solder joint had obvious bridging, the pad of base side thermal imaging system A showed as low temperature, and the two or more temperature rises of meeting district, the chip relevant position that opposite side thermal imaging system B absorbs, shown in Figure 10 and 11.
Therefore when defective is serious, only two thermographies need be compared and just can obtain judged result intuitively.
Claims (7)
1. two thermal imaging system infrared measurement of temperature detection methods of a upside-down mounting welding core welding point defect is characterized in that described method step is as follows:
Side at flip-chip arranges a thermal imaging system A, in substrate one side a thermal imaging system B and infrared laser are set, the laser beam diameter is slightly less than pad, infrared laser beam is aimed at flip-chip substrate pad to be measured, adjust power and pulsewidth parameter, it is imposed thermal excitation, thermal imaging system A and thermal imaging system B be difference detection laser light spot substrate pad place and the temperature rise process in chip soldered ball district in real time accordingly simultaneously, observe and take the heat picture of temperature rise peak simultaneously, judge the upside-down mounting welding core welding point defect according to temperature rise curve or thermography.
2. the two thermal imaging system infrared measurement of temperature detection methods of upside-down mounting welding core welding point defect according to claim 1 is characterized in that described laser beam diameter is less than pad diameter.
3. two thermal imaging system infrared measurement of temperature detection methods of upside-down mounting welding core welding point defect according to claim 1, it is characterized in that when solder joint exists scarce ball, rosin joint, pore, crack defect, the temperature rise curve temperature difference maximum that the temperature rise curve that thermal imaging system A surveys and thermal imaging system B survey is far above both temperature difference of qualified solder joint.
4. two thermal imaging system infrared measurement of temperature detection methods of upside-down mounting welding core welding point defect according to claim 1, it is characterized in that when there is the bridging defective in solder joint, the temperature rise curve temperature difference minimum that the detected temperature rise curve of thermal imaging system A and thermal imaging system B survey is less than both temperature difference of qualified solder joint.
5. the two thermal imaging system infrared measurement of temperature detection methods of upside-down mounting welding core welding point defect according to claim 1 is characterized in that when scarce ball, big crackle, gross blow hole, when the bridging defective is serious, judge by the contrast heat picture.
6. two thermal imaging system infrared measurement of temperature detection methods of upside-down mounting welding core welding point defect according to claim 5, it is characterized in that under scarce ball, big crackle, gross blow hole situation, the pad of thermal imaging system A shows as high temperature, and the chip relevant position that thermal imaging system B absorbs does not have the temperature rise phenomenon substantially.
7. two thermal imaging system infrared measurement of temperature detection methods of upside-down mounting welding core welding point defect according to claim 5, it is characterized in that when tested solder joint has obvious bridging, the pad of thermal imaging system A shows as low temperature, and the chip corresponding positions that thermal imaging system B absorbs is equipped with two or more temperature rises district.
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Cited By (9)
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| CN105424752A (en) * | 2015-11-18 | 2016-03-23 | 中国电子科技集团公司第三十八研究所 | Detection method for performing point-by-point scanning temperature measurement on BGA chip welding spot defects |
| CN106872848A (en) * | 2017-02-17 | 2017-06-20 | 安徽国家铜铅锌及制品质量监督检验中心 | A kind of printed circuit board (PCB) thermal imaging testing method and device |
| CN106980721A (en) * | 2017-03-21 | 2017-07-25 | 电子科技大学 | A kind of rosin joint detects Finite Element Simulation Analysis method |
| CN108181190A (en) * | 2017-12-26 | 2018-06-19 | 大连交通大学 | A kind of dissimilar material tack-weld fatigue limit method for quick predicting |
| CN110081924A (en) * | 2018-01-25 | 2019-08-02 | 韩华精密机械株式会社 | The scaling powder of flip-chip coats state detection method |
| EP3862733A1 (en) * | 2020-02-05 | 2021-08-11 | Siemens Gamesa Renewable Energy A/S | Temperature measurement assembly |
| CN113447527A (en) * | 2021-06-11 | 2021-09-28 | 西安交通大学 | Dual-mode laser infrared thermal imaging detection system and method |
| CN114136460A (en) * | 2021-12-02 | 2022-03-04 | 中国海洋大学 | Water body temperature vertical section observation device and method |
| CN114894843A (en) * | 2022-05-17 | 2022-08-12 | 金陵海关技术中心 | Metal spot welding thermal wave imaging nondestructive testing method |
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Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN105424752A (en) * | 2015-11-18 | 2016-03-23 | 中国电子科技集团公司第三十八研究所 | Detection method for performing point-by-point scanning temperature measurement on BGA chip welding spot defects |
| CN106872848A (en) * | 2017-02-17 | 2017-06-20 | 安徽国家铜铅锌及制品质量监督检验中心 | A kind of printed circuit board (PCB) thermal imaging testing method and device |
| CN106980721A (en) * | 2017-03-21 | 2017-07-25 | 电子科技大学 | A kind of rosin joint detects Finite Element Simulation Analysis method |
| CN108181190A (en) * | 2017-12-26 | 2018-06-19 | 大连交通大学 | A kind of dissimilar material tack-weld fatigue limit method for quick predicting |
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| EP3862733A1 (en) * | 2020-02-05 | 2021-08-11 | Siemens Gamesa Renewable Energy A/S | Temperature measurement assembly |
| CN113447527A (en) * | 2021-06-11 | 2021-09-28 | 西安交通大学 | Dual-mode laser infrared thermal imaging detection system and method |
| CN113447527B (en) * | 2021-06-11 | 2022-10-25 | 西安交通大学 | Dual-mode laser infrared thermal imaging detection system and method |
| CN114136460A (en) * | 2021-12-02 | 2022-03-04 | 中国海洋大学 | Water body temperature vertical section observation device and method |
| CN114136460B (en) * | 2021-12-02 | 2024-04-05 | 中国海洋大学 | Device and method for observing water body temperature vertical profile |
| CN114894843A (en) * | 2022-05-17 | 2022-08-12 | 金陵海关技术中心 | Metal spot welding thermal wave imaging nondestructive testing method |
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Application publication date: 20130807 |