TW507079B - Method for detecting soldering failure in IC terminal by tuning type sensor coil - Google Patents

Abstract

The object of the present invention is to provide a method for detecting the soldering failure in IC terminal by tuning type sensor coil to electrically detect the soldering of an IC terminal at a high speed. A tuning type sensor coil provided with a sensor coil formed by winding a plurality of conductive coils on a cylindrical bobbin formed of a magnetic material core such as ferrite or the like having a diameter conformed to the outer dimension of an IC and a capacitor connected to the output end of the sensor coil, is set on the IC. A means for applying an AC (sine wave, pulse, etc.) signal to a measuring terminal in the IC grounded except the measuring terminal to detect the magnetic field generated by the current carried to a protective diode within the IC by the tuning type sensor coil set on the IC is given to all of the IC terminals. By the detection means of the tuning type sensor coil disposed on the IC, all of the IC terminals are measured. The propriety is judged by the comparison with a preliminarily stored reference value for non-defective IC.

Description

刈 7079 V. Description of the invention α) [Detailed description of the invention] [Technical field to which the invention belongs] The present invention relates to a detection method for detecting the soldering quality of the solder mounted on a printed terminal at an electrical high speed. I c of the circuit board, and it can also detect the wires without BG Α and so on; [c Xihui [Known Technology] < Good or not. According to the method of detecting the soldering quality of 1C wire according to the conventional technology, Patent Publication No. 6-347H is disclosed. In order to set the electrostatic capacitance value that has been set on the IC between the Bayan film and the lead frame of the IC, it is printed by Circuit, Meng case measurement, the method of comparing the capacitance value with a good product ^ ^ bad method. The soldering of the ¥ wire is also disclosed in Japanese Patent Laid-Open No. 10_ 1 9958. —The entire 1C side will be protected inside the terminals of the IC = the temperature change of the electrical material through the printed circuit. The second board::; = then 'the temperature change is compared with a good product to detect soldering [problem to be solved by the invention] {said "kz: 4 A, the problem to be solved according to the above-mentioned conventional technology". There are many testing methods for knowing good and bad. There are many methods for testing soldering, such as the 1st flit Kaiping " 4m, which is difficult to apply to Ic State without lead frame-! No. 9958 soldering. Detection method) This patent discloses this, and the determination time for measurement becomes too long. . ,,, and%, because [means to solve the problem]

507079 V. Description of the invention (2) The present invention is made to eliminate the above-mentioned conventional techniques ^ ^ has been revalued < shortcomings, the current from the pattern of the printed circuit board to make the current flow to the bed ^ 丄 金 心 王 饭 口It is also recognized by the internal circuit of each terminal of the IC, and the 丨-* + — p ° and the tuning-type sensing coil with resonance circuit detects the magnetic field generated by its current to detect the quality of soldering. That is, an AC signal (sine wave, current that does not give the stress of the IC by comparing with a reference value of a good product, and a pulse on the printed circuit board connected to the IC terminal, etc.) is added to the pattern on the IC to be inspected. The internal circulation of I c is compared with the ratio of ▲, the ratio of the agent, the day, and the number of people, and the magnetic field generated by the = type sensing coil with a resonance circuit at the top of 1 c detects the current flowing in the IC.供给 The c-terminal supply current i is set to ground. After the signal is amplified, the signal is amplified, and the detection conversion is small. It is determined that the ic terminal is not correctly soldered to the pattern of the P brush circuit board. Check all the terminals on 1C. In order to effectively detect the magnetism generated by the current flowing in the 1C: a flat plate with a planar size corresponding to the IC's external dimensions;; ::: = 1 surface coil or vortex coil sensing The flat coils are equipped with ,,,, and '㈣ 雷 备 电 SM wires, so that the two coils become the same pole! It is also electrically connected in series to increase the magnetic detection sensitivity. [Embodiment of the invention] Hereinafter, the present invention will be described with reference to the drawings, with reference to the sensing coil. Page 5 \\ 312 \ 2d-code \ 90-08 \ 90113177.ptd

V. Description of the invention (3) Method for measuring poor soldering of IC terminal. Fig. 1 is an explanatory diagram showing the measurement of magnetoelectricity II with a parallel resonance lightning current ㈣ on an IC3 equipped with a large number of terminals. ^ r τ ^ ^ On, there is a tuning-type sensing coil 1. # U4 拉 寺) Heart break source 1 2 is the printed circuit board to which I 4 is connected to the measurement target of I C3. Τ Τ Λ. The pattern on the power supply, the other terminals are all connected to the 1C power supply or GND terminal 5.: The electric current flowing into the IC from the AC signal source 12 through the measurement target terminal 4 is to form a loop circuit through the built-in 1 (: protection diode to GND terminal). The t μ ^ $ provided by the signal source 12 to the measurement target terminal 4 will give a small current of the ic stress level, usually a value not exceeding 20 μα to ± 50 mA, which is the absolute maximum recorded in the device data sheet. Electric current. "The tuning-type sensing coil 1 is a bobbin made of a magnetic material core such as ferrite having a diameter corresponding to the external dimensions of Ic, and a plurality of conductive coils are wound back to form a coil-shaped sensor. Then, the two ends of the coil-shaped sensor are connected in parallel with the capacitor 1 丨 to form a parallel resonance circuit. A tuning-type sensing coil is provided. FIG. 2 shows a tuning-type sensing coil provided with a parallel resonance circuit and an attached tuning coil. * Block diagram of the composition of the detection circuit f If the frequency of the AC signal source 12 is set to 128KHz, the frequency of the magnetic field generated in Ic is tuned to obtain the parallel resonance with the highest detection sensitivity. The constant of ^ 3 is the number of torsion of the coil is 464, and the capacitance of the capacitor is 300. pF.

\\ 312 \ 2d-code \ 90-08 \ 90113177.ptd Page 6 507079 V. Description of the invention (4) Pa Shan from the parallel resonance circuit 1 3 # · Detected in the DC detector 14 m; by the amplifier 6 is amplified, and the above-mentioned AC signal source === quasi is a number of 10_. Can be appropriately selected. The wave number or parallel connection, the constant of the vibration circuit = the output of the device 14, and the good reference value 15 memorized in advance are compared in the comparison judging unit 16, and the judgment of the failure is performed.丨 Value 15 in ratio

Fig. 3 is a block diagram circuit equipped with a series J detection circuit, which is a spectrum tuning type sensing coil and a series resonance circuit 13 provided in the tuning type sensing coil 1. ^ 'Capacitor 11' is connected in series to form a magnetic field 1 = 1 Gonghao source: The frequency of the 12th wave is 128, so that the series resonance circuit with 1C internal modulation / the highest detection sensitivity is VpF and the number of twists is 28 ° The electric capacity of the series capacitor U ', then 1 ΐ ί 1 According to the current of the protection diode flowing through Ic to be efficiently detected,% 4, so that the size of I㈣ corresponds to the external size of ie is better. However, the external dimensions of the IC have various gardens depending on the type or purpose of use. "To adapt to the individual I c ', a number of spectrum-modulated sensing circles must be prepared. This requires not only time and effort, production, and low price. F Besides, it ca n’t be expected to use a large number of ^ 4, so that the same type of tuning coils can be adapted to various ^ inches of K, and the sensing flat coils with a flat size corresponding to the heart-shaped shape are made first. 507079

An explanatory diagram showing a state in which a flat-shaped sensing plate wire · 'is mounted under the tuning type sensing coil 1 so that the polarities of the two coils are the same and they are electrically connected in series. The size of the sensing plate coil 2 made of a conductive plate such as copper is the external size corresponding to κ3. The central portion of the plate-shaped conductive plate is opened to a circle. Like a 1-turn coil, it is opened to a circle and a plate. Between the sides, there is a gap formed by cutting the flat plate. Since the tuning type sensor coil and the sensing flat coil 2 are connected in series with the same polarity, the detection sensitivity of the magnetic field can be improved by using two coils. Although one sensing flat coil can be used, the detection sensitivity can be increased by overlapping a large number of coils. If a printed circuit board with double-sided copper foil is used, two overlapping planar coils can be easily made. [Effects of the Invention] As described above, according to the soldering defect detection method of the present invention, since a tuned sensing coil provided with a resonance circuit is used, the measurement method is simple, and high-speed inspection can be performed at a few ms per terminal required time. . For ICs with different external dimensions, if a sensing flat coil can be made that can correspond to the individual IC external dimensions, the size of the tuned plastic sensing coil installed on it can achieve a stable measurement and discrimination detection method with only one type. [Explanation of component number] 1 Tuning sensing coil 2 Sensing flat coil

3 1C

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507079

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Page 9 507079 Brief Description of Drawings Figure 1 is an explanatory diagram showing a method for detecting soldering failure by measuring a magnetic field of an internal current of an IC by using a tuned sensing coil having a parallel resonance circuit. Fig. 2 is a block diagram showing a circuit configuration of a tuning type sensing coil having a parallel resonance circuit. Figure 3 shows a block diagram of the circuit configuration of a tuned sensing coil having a series resonance circuit. & Fig. 4 is an explanatory diagram of joining a tuning type sensing coil and a sensing flat coil to increase magnetic sensitivity.

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Claims (1)

507079 、 Applicable patent scope 1. A method for detecting soldering failure of IC terminals by using a tuned sensing coil to detect soldering of IC terminals mounted on a printed circuit board: The method is characterized in that, it can be used in 1C A bobbin made of a ferrite core with an external diameter and a diameter, and a plurality of conductive coils are wound back. The output end is equipped with a wheel circuit or a series resonance circuit for connecting capacitors in parallel or in series. The type sensing coil is set at Ic: when vibrating,, and are the same. :, The printed circuit board connected to the terminal of the measurement object is added with a parent,: (sine wave, pulse wave, etc.) signal, so that the electric diagram: the protection diode of the part generates a magnetic field; The modulation-type sensing is large, and the hand-held quality of the soldering is compared with the accuracy of the DC amplifier after detection. ^ 1 I have already learned the basics of good products. In addition, all 1C terminals are subjected to 2. The method of sub-soldering failure according to item 1 of the scope of patent application, wherein we! The flat coil-shaped conductive plate that detects the size of the IC at the end of the sensing coil is formed as a flat plate coil corresponding to the IC's external dimensions. The flat coil is mounted on the tuned coil or vortex winding spectrum-type sensing coil and the flat plate coil. 'Below the coil, the aforementioned tuning coil is electrically connected in series to form a line: ^ Same as the electrode', so that the aforementioned 2 connection or series connection forms a parallel resonance 5 ^ wheel & end 'The capacitor is connected in parallel Series resonance circuit, so