CN101382573A

CN101382573A - Induction voltage testing method

Info

Publication number: CN101382573A
Application number: CN 200710166589
Authority: CN
Inventors: 林杰清
Original assignee: Beijing Star River Comtes Science & Technology Development Co Ltd
Current assignee: Beijing Xinghe Taishite Technology Co ltd
Priority date: 2007-11-07
Filing date: 2007-11-07
Publication date: 2009-03-11
Anticipated expiration: 2027-11-07
Also published as: CN101382573B

Abstract

The invention relates to a test method of induction voltage, which comprises the following steps: an alternating current signal (AC signal) of 10 KHz and 5V is added on a pin; the induction voltage can be tested by an induction probe arranged above a tested device and the state information of the tested device can be obtained by an amplifying circuit; the good and bad of the connection of each pin as well as the good and bad of the internal circuit structure of the tested device can be judged by testing the weak and strong of the induction voltage as well as the distribution state thereof; separating pin grounding or a voltage source with certain electric potential is utilized for eliminating interference. The method has the beneficial effects that: regardless of whether the IC chips with the same specification and size are connected in parallel, the state of each IC chip or the tested device on the circuit board can be measured accurately; the test to the state of the chip is strengthened, and more reliable basis can be provided for the accuracy and intactness of the IC chip after welding; the test to the reliability of a circuit board module is strengthened; the test method of the common devices is enforced, and the reliable basis is provided for comprehensively analyzing the state of the devices.

Description

A kind of induction voltage testing method

Technical field

The present invention relates to the online connection reliability testing of a kind of components and parts and circuit board module (being designated hereinafter simply as measured device) technology, relate in particular to the induction voltage testing method of a kind of IC chip, common element, circuit board module.

Background technology

Along with science and technology development, the IC chip of modularization, high integration is widely used in the circuit design.When the circuit board that connects in butt welding was tested, the test of the quality that the quality and the pin thereof of IC element welded on circuit board was necessary step; Current universal method is the mode to the test of IC inside PN junction; nearly all digital IC and a large amount of analog IC chips all are connected to the PN junction of anti-overvoltage protection between its input and output pin and power pin; by being arranged on and the probe of IC pad on same track; the existence of measuring this PN junction whether with and direction, then can judge the leakage weldering of tested IC pin and the correctness of IC direction.Test to PN junction generally has two kinds of methods:

(1) PN junction nonlinear curve mensuration: as Figure 1-1,, measure and thisly non-linearly can distinguish PN junction and conventional, electric-resistance because the relation of electric current and voltage is non-linear during the PN junction forward conduction.Therefore when judging whether certain point-to-point transmission has the PN junction characteristic, use this method always, add the different current source of current value at two ends twice, read both end voltage then, by the nonlinear characteristic of electric current and voltage, can judge the existence of diode, also can judge the bad diode of on state characteristic;

(2) the forward and reverse mensuration of PN junction: shown in Fig. 1-2, respectively the measured point is applied forward and reverse two kinds of voltages with the voltage source that has certain source resistance, the magnitude of voltage at test PN junction two ends, what read is conducting and cut-off voltage, to obtain two unequal voltages of V1, V2 to common PN junction, and equate on absolute value with V2 for two-way PN junction (or antiparallel two PN junctions) V1, but the PN junction on a certain direction has been broken or anti-the dress all can influence measurement result.

More than two kinds of method of testings, when obtaining the standard testing data test, by with normal data to the quality of each pin solder joint of recently obtaining the IC chip and the correctness that IC installs.It is fine that above method is tested single IC chip effect, but be not suitable for and the situation that two above IC pins in parallel are arranged, and also is not suitable for the situation of IC pin parallel diode; After the PN junction parallel connection, the family curve that records during test as long as there is a PN junction to exist, just can obtain family curve, and the situation of losing a PN junction can not influence its family curve, thereby can't measure.

Summary of the invention

The purpose of this invention is to provide a kind of induction voltage testing method, aspect IC and circuit board module on-line testing, no matter make whether IC chip or circuit board module be in parallel, the accurate state of each IC chip or circuit board module on the metering circuit plate, with overcome prior art be not suitable for measuring two above IC and connecting leg pin are arranged, the deficiency of IC pin parallel diode situation, it is single to overcome prior art testing circuit board modular approach, the deficiency of data reliability difference strengthens the ability of common components and parts being carried out analysis-by-synthesis.

The objective of the invention is to be achieved through the following technical solutions:

A kind of induction voltage testing method may further comprise the steps: the AC signal that adds 10KHz, 5V on the measured device pin; By settling above it inductive probe to record induced voltage and obtaining the status information of chip through amplifying circuit; Judge the quality of each pin connection and the quality of internal circuit configuration by the power, the distribution that record the induced voltage on the measured device.

With IC is example, because the influence of IC peripheral circuit element, when IC pin to be measured was opened a way, the signal that is applied to this network can be coupled to the inner test result that influences of IC by other element.Can the survey rate in order to improve, need add isolation, eliminate the signal cross-talk between the IC pin; Use to isolate on the voltage source of pin ground connection or certain potentials and eliminate interference, it is provided with order and generally is: with IC pin to be measured the adjacent needles number of the GND of pin pin that element links to each other number, IC or VCC pin, the adjacent pin of pin to be measured, pin pin to be measured number is arranged.

The principle of IC chip voltage induction method of testing of the present invention: when IC chip energising work, because weak current, light current are pressed and are acted on the link of IC inside, have the accumulation of electric charge on integrated circuit substrate, burial layer and the metal lead wire, can make the IC surface can produce induced potential, not have induced potential during no power; And the internal communication circuit structure of different pins, form, layout difference, the induced potential that its different pin is produced is also different; Even thereby the parallel connection of IC chip, pin connects together, and also can judge the quality that each pin of IC chip connects and the quality of internal circuit configuration by the power, the distribution that record the induced voltage on the chip, there is not the influence of interference in the IC chip chamber.Because induced potential is more small and weak, be not easy to direct measurement, also be not easy to directly metal probe is pressed on the IC chip, thereby the coupling of utilization interchange obtains the induced potential on the IC chip indirectly, by amplifier it is amplified again, can obtain the signal that to survey.

The beneficial effect of induction voltage testing method of the present invention is: that has improved the IC chip can the survey rate, has strengthened the test to chip status, can provide more reliable foundation to accuracy, the integrity of IC chip for welding the back; For the state of circuit board module provides more reliable data; For the common components state is carried out analysis-by-synthesis, screening provides more multi-method foundation.

Description of drawings

With reference to the accompanying drawings the present invention is described in further detail below.

Fig. 1-1 and Fig. 1-2 are two kinds of non-linear synoptic diagram of electric current and voltage of testing the PN junction methods commonly used at present;

Fig. 2 is the voltage induced survey sheet of the described IC chip voltage induction of embodiment of the invention method of testing;

Fig. 3 is the inductive probe circuit diagram of the described IC chip voltage induction of embodiment of the invention method of testing;

Fig. 4 is the circuit board component figure of the described IC chip voltage induction of embodiment of the invention method of testing;

Fig. 5 is the circuit board wiring layout of the described IC chip voltage induction of embodiment of the invention method of testing.

Embodiment

Shown in Fig. 2-5, the described object lesson IC of embodiment of the invention chip voltage induction method of testing may further comprise the steps: the AC signal that adds 10KHz, 5V on the IC pin; Record induced voltage and obtain the status information of chip through amplifying circuit by the voltage induced probe that is placed in IC chip top; Judge the quality of each pin connection of IC chip and the quality of internal circuit configuration by the power, the distribution that record the induced voltage on the IC chip.

Eliminate interference by using on the voltage source of isolating pin ground connection or certain potentials, it is provided with order: with IC pin to be measured the adjacent pin (PIN3 of test I C for example of the GND of pin pin that element links to each other number, IC or VCC pin, pin to be measured is arranged, then the pin of PIN2 and PIN4 number is made as and isolates pin), the adjacent needles number (for example the PIN3 of IC to be measured is No. 20 pins, and then No. 19 pins and No. 21 pins are made as and isolate pin) of pin pin to be measured number.

Two triodes of the positive welding of the circuit board of described voltage induced probe 1, three sticking-elements of reverse side welding: two resistance, a triode; Pad pitch of holes and pin welding method comprise: prepare the IC pin of four circles, cut for thin one and throw away, a thick remaining 4.5-5mm; Get remaining one section, a thin slightly polishing, but do not grind, it is long standby to be milled to 4.5mm; Standby pin hole up (greatly head-up) insert 15 and 16 holes, be inserted into the end and vertical welding is connected to circuit board; Standby pin hole (carefully head-up promptly) is down inserted 13 and 14 holes, is inserted into the end and vertical welding is connected to circuit board; Described capacitive sensing circuit board is a double face copper, two pad holes use the resistance leg of diameter 0.6mm in the positive vertical welding of circuit board, circuit board can be selected wherein one type or cutting voluntarily according to the size of IC area, at last two circuit boards is assembled together.

Claims

1, a kind of induction voltage testing method is characterized in that, may further comprise the steps:

The AC signal that on pin, adds 10KHz, 5V;

Record induced voltage and obtain the status information of measured device through amplifying circuit by the inductive probe that is placed in measured device top;

Judge the quality of each pin connection of measured device and the quality of internal circuit configuration by the power, the distribution that record induced voltage.

2, induction voltage testing method according to claim 1, it is characterized in that: use on the voltage source of isolating pin ground connection or certain potentials and eliminate interference, it is provided with order: with measured device pin to be measured the adjacent needles number of pin pin that element links to each other number, the adjacent pin of pin to be measured, pin pin to be measured number is arranged, during to IC chip testing, the GND of IC or VCC pin.

3, induction voltage testing method according to claim 1 and 2 is characterized in that: two triodes of the positive welding of the circuit board of the amplifying circuit of described inductive probe, three sticking-elements of reverse side welding: two resistance, a triode; Pad pitch of holes and pin welding comprise: prepare the IC pin of four circles, cut for thin one and throw away, a thick remaining 4.5-5mm; Get remaining one section, a thin slightly polishing but do not grind, be milled to 4.5mm and grow standby; Standby pin hole patchhole (15) and (16) up, standby pin hole is patchhole (13) and (14) down, are inserted into the end and vertical welding is connected to circuit board.