WO2006082294A1 - Procede de test d'elements electriques utilisant un effet photoelectrique indirect - Google Patents
Procede de test d'elements electriques utilisant un effet photoelectrique indirect Download PDFInfo
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- WO2006082294A1 WO2006082294A1 PCT/FR2006/000155 FR2006000155W WO2006082294A1 WO 2006082294 A1 WO2006082294 A1 WO 2006082294A1 FR 2006000155 W FR2006000155 W FR 2006000155W WO 2006082294 A1 WO2006082294 A1 WO 2006082294A1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R29/00—Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00
- G01R29/24—Arrangements for measuring quantities of charge
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/28—Testing of electronic circuits, e.g. by signal tracer
- G01R31/302—Contactless testing
- G01R31/308—Contactless testing using non-ionising electromagnetic radiation, e.g. optical radiation
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/28—Testing of electronic circuits, e.g. by signal tracer
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/28—Testing of electronic circuits, e.g. by signal tracer
- G01R31/302—Contactless testing
- G01R31/308—Contactless testing using non-ionising electromagnetic radiation, e.g. optical radiation
- G01R31/311—Contactless testing using non-ionising electromagnetic radiation, e.g. optical radiation of integrated circuits
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/28—Testing of electronic circuits, e.g. by signal tracer
- G01R31/302—Contactless testing
Definitions
- the present invention relates to the electrically non-contact test of electrical conductors arranged on an insulating substrate, using the photoelectric effect.
- the present invention particularly relates to the electrical test of interconnect carriers, such as printed circuits and chip carriers or "chip carriers".
- the electrical test of interconnect supports represents a major challenge for the modern electronics industry and is an integral part of their manufacturing process.
- the two essential test sequences to conduct to verify that an interconnect conductor has no manufacturing defect are conventionally the continuity test and the insulation test.
- the continuity test consists in checking that the conductor is not cut between its ends, more precisely between the connection points that it connects, generally contact pads. This is to measure the resistance of the driver between the connection points of the driver and to ensure that it is very low (typically of the order of one ohm).
- the isolation test is to ensure that each conductor of the interconnect carrier is electrically insulated from other conductors, that is, it has relative to each of the other conductors and relative to all other conductors an insulation resistance of high value, typically of several megohms.
- interconnect carriers With the miniaturization and complexification of integrated circuits made in the form of silicon chips, interconnect carriers have a growing complexity in the image of that of the integrated circuits they host. Thus, the high density interconnect carriers have conductors whose width and length are constantly decreasing, and the surface of their connection points with integrated circuits. As a result, conventional test methods using spike cards or nail beds are becoming increasingly unsuitable for such interconnect carriers.
- HDI High Density Interconnect
- chip carriers or “chip chopper” also known as “IC package substrates”, “FC-BGA”, “Flip Chips”, “Bail Grid Arrays” ...
- the “chip carriers” are actually intermediary interconnection supports adapters, "or spark gaps", which are interposed between the integrated circuits and the printed circuits, because the integrated circuits generally have a pitch (minimum distance between conductors, especially between input / output contacts) much lower than the pitch of the printed circuits.
- solder microbeads with a diameter of a few tens of micrometers. They also have on their back side connection points with a printed circuit board
- C4 Controlled Collapsed Chip Connection
- BGA Backplane connection points
- Such "chip carriers” also present drivers connecting C4 points to BGA points, called “C4-to-BGA” (conductors including "vias", that is to say, metal channels passing through the substrate on each side.
- C4-to-C4 conductors connecting on the front of C4 points, called "C4-to-C4", serving only to interconnect in pairs of the contacts of the integrated circuit without connection to the rear face and therefore without connection with the external environment.
- C4-to-C4" conductors are particularly difficult to test because they are inaccessible from the back of the "chip carrier” and have a low pitch of a few tens of micrometers.
- a test method suitable for testing such interconnect carriers must satisfy the following requirements: provide access to all connection points of conductors, including C4-to-C4 or C4-to-C4 conductors BGA, knowing that the distances between the connection points are small and of the order of a few tens of micrometers (distance between points of type C4) to a few hundred micrometers (distance between points of type BGA.),
- connection points not being destructive with respect to the connection points, in particular the points of type C4 (the solder microbeads being fragile and generally deposited before the test phase), and
- contactless test methods have been developed in which the effect of photoelectric is used to act on the electrical potential of the conductors to be tested.
- the photoelectric effect is caused by applying to a conductive material a beam of particles having sufficient energy to cora ⁇ unicate electrons of the conduction layer of the target material energy at least equal to their work function ("work function").
- work function work function
- the electrons are then torn - ejected - from the conductive material with a determined kinetic energy, which can be almost zero, and are then accelerated by an intense electric field (several million volts per meter).
- photoelectric effect is here generic and refers to a phenomenon of tearing or ejection of electrons from a target material.
- materials such as copper, gold, or lead tinned conductors
- short wavelength coherent light sources especially ultraviolet light sources
- sources of Non-coherent light are also used as well as particles other than photons, for example an ion beam or an electron beam.
- the photoelectric effect has been exclusively used to eject electrons from a conductor to be tested.
- a collection electrode raised to a positive potential solves this problem by generating a powerful electric field that attracts electrons ejected by the driver.
- the collection electrode also allows the collection and counting of the amount of electricity extracted from the conductor to deduce, for example, its initial electrical potential.
- the electrical potential of the conductor is the same as that of the collection electrode (when the conductor is at a floating potential).
- International application WO 01/38892 provides a major improvement to the test methods based on the photoelectric effect, by providing an electron injection in a conductor in addition to an electron extraction. The injection of electrons is ensured by means of a discharge electrode
- Electrode Electrode brought to an electrical potential lower than that of the conductor to be tested, disposed opposite it and bombarded by a particle beam.
- FIG. 1A illustrates the method of injecting electrons into a conductor as described in the international application.
- the target conductor 1 is arranged on a dielectric substrate 2 and has a contact pad 3 (connection point) covered here with a solder layer.
- a discharge electrode 6 integral with a silica support plate 5 is disposed at a distance d from the conductor, opposite the range 3 (delimited here by a savings zone made in a protective varnish 4).
- the discharge electrode 6 receives a negative electric potential Vn less than a floating potential Vf of the conductor, and its rear surface is bombarded by a beam BI of ultraviolet light, via the plate 5 and in the presence of a vacuum primary.
- Fig. 1B illustrates a method of ejecting electrons present in the conductor 1 as described in the international application.
- a collection electrode 7, fixed to the support plate 5, is disposed at a distance from the contact area 3 of the conductor 1 and is brought to a positive electrical potential Vp greater than the floating potential Vf of the conductor.
- this method has the disadvantage that the discharge electrodes 6 must have a very small thickness, because the light beam is applied to their rear face while the ejection of electrons is made from their front face.
- This thickness is of the order of 100 to 150 Angstroms, barely greater than the skin thickness (50 to 100 ⁇ ) of the metal used, knowing that the photons, as part of the photoelectric effect, penetrate into the metal at a temperature of depth of about 50 to 100 Angstroms. It follows that the discharge electrodes are fragile, subject to oxidation and various other phenomena that may cause their slow degradation over time.
- the present invention is directed to an injection method in an electron conductor provided by a discharge electrode, which does not require applying to the rear face of the discharge electrode a beam of particles generating a photoelectric effect. .
- the present invention also relates to a method for bringing to an electrical potential a target electrical conductor arranged on an electrically insulating substrate and at an initial electrical potential greater than the targeted electrical potential.
- the present invention also relates to a method of testing or measuring electrical elements involved in the manufacture of electronic circuits, including testing or measuring conductors, electrical components, electronic components or terminals of electrical or electronic components.
- the present invention is based on a surprising finding made by carrying a collection electrode at a negative voltage while a target conductor, initially at a floating potential of zero (mass), is bombarded by an ultraviolet light beam.
- a target conductor initially at a floating potential of zero (mass)
- the purpose of such an experiment was to verify that the electric potential of the driver did not change after the "shot", because the electrons torn from the driver were supposed to reinject into it because of the repulsive electric field generated by the negative voltage electrode Collects.
- the driver was at the same negative potential as the pickup electrode, indicating that the driver did not lose electrons and instead received a significant amount of electrons.
- the present invention is based on the finding that the metals or materials conventionally used to form the interconnecting conductors or cover them, in particular copper, gold, solder lead-free tin, as well as C4 or BGA type solder balls, have a good reflection coefficient with respect to the particle beams used to cause the "photoelectric" effect, in particular the beams of ultraviolet light.
- the idea of the invention is to extract electrons present in a discharge electrode by means of a reflected particle beam from an incident beam applied to and reflecting on a target conductor.
- the discharge electrode being struck by the beam from its front face (by convention the front face is the one facing the target conductor) instead of being struck on its back side, the constraint imposed by the art previous, to provide a discharge electrode of very small thickness, becomes irrelevant.
- the present invention provides a method for bringing an electrical conductor at an electrical initial potential floating above the target electrical potential to an electrical potential, comprising the steps of placing at least one discharge electrode in the vicinity of the conductor. electrons, carry the discharge electrode to the target electrical potential, and eject electrons from the discharge electrode by means of a particle beam and inject into the conductor the electrons provided by the discharge electrode, in which process the ejection of electrons from the electrode of discharge comprises applying to the discharge electrode a reflected particle beam from reflection on the conductor of an incident particle beam.
- the initial floating electrical potential of the conductor is a mass potential or a positive potential relative to the ground potential
- the target electrical potential is a negative potential relative to the ground potential
- the method comprises a preliminary step of bringing the conductor to the initial electrical potential.
- the conductor is brought to the initial potential by bringing the electrode to the initial electrical potential and applying to the conductor the particle beam so that electrons are ejected from the conductor and reach the electrode by making the electric potential from the conductor to the electrical potential of the electrode, which then forms an electrode for collecting electrons.
- the reflected particle beam has an intensity of between 30 and 85% of the intensity of the incident particle beam impinging on the conductor.
- the discharge electrode comprises a surface treatment to maximize the electron ejection under the effect of the reflected particle beam.
- the particle beam is a beam of ultraviolet light.
- the ejected electrons and the reflected particle beam are channeled through an orifice in an electrically insulating separator plate disposed between the discharge electrode and the conductor.
- the electrical conductor is a conductive track, a contact pad or a terminal of an electronic component.
- the invention also relates to a method for testing or measuring electrical elements by means of at least one electron discharge electrode, at least one collection electrode. of electrons and at least one source of a particle beam, comprising ejecting electrons present in the discharge electrode by means of the particle beam and injecting into an element the electrons provided by the IEC 60050 - International Electrotechnical Vocabulary - Details for IEV number 845-02-35 Electron emission and discharge of electrons from an element by means of the particle beam and collection by the collecting electrode of electrons ejected from the element, in which the ejection of electrons present in the electron
- the discharge electrode comprises applying to the discharge electrode a reflected particle beam from reflection on at least one element of an incident particle beam.
- the discharge electrode and the collection electrode are of the same structure, the discharge electrode being able to form a collection electrode or vice versa.
- the method comprises the steps of carrying a first element to a first electrical potential by ejecting electrons present in the first element, bringing a second element to a second potential electrically lower than the first electrical potential by injecting electrons into the second element, and measuring the electrical potential of at least one of the elements after a lapse of time.
- the method comprises the steps of drawing a first element to a first electrical potential by ejecting electrons from the first element, drawing a second element to a second electric potential lower than the first electrical potential, by injecting electrons into the second element, and measuring an electrical charge flowing between the first and second elements.
- the method comprises the use of an electron discharge and collection plate having a plurality of electrodes, each of which can form an electron discharge electrode in an electron collecting element or electrode. electrons ejected from an element, and having between the electrodes spacings allowing a part of the beam of particles to cross the discharge plate and electron collection and reach elements.
- each electrode is individually accessible for application to the electrode of an electric potential.
- the electrodes comprise a surface treatment in order to maximize the ejection of electrons present in the electrodes under the effect of the reflected particle beam.
- each electrode comprises a grid of thin conductors.
- each electrode comprises a block of a conductive material.
- the electron discharge and collection plate comprises electrodes arranged in a matrix manner, in rows and in columns.
- the discharge and electron collection plate comprises electrodes parallel to each other.
- the electron discharge and collection plate comprises electrodes in the form of rectilinear strips.
- the method comprises using an electrically insulating separator plate between the electron discharge and collection plate and elements, the separator plate including orifices at locations corresponding to injection points. or electron collection, and forming corridors of electron circulation and channeling of the particle beam.
- the particle beam is a beam of ultraviolet light.
- an electrical element is at least one of the following elements: an electrical conductor, an electrical component, an electronic component, a terminal of an electrical conductor or a terminal of an electrical or electronic component.
- the invention also relates to a method for manufacturing an interconnection support or an electronic circuit arranged on an interconnection support, the interconnection support or the electronic circuit comprising electrical elements, the method comprising a step testing or measuring all or part of the electrical elements of the interconnection support or the electronic circuit implemented in accordance with the test or measurement method according to the invention.
- the invention also relates to a device for testing or measuring electrical elements, comprising at least one source of a particle beam, at least one discharge and electron collection plate comprising a plurality of electrodes that can be carried. individually to an electrical potential, a control and measuring unit, for controlling the particle beam and the electric potentials applied to the electrodes, and measuring electrical charges flowing through the electrodes, the device being arranged to eject electrons present in electrodes by means of the particle beam and injecting the electrons supplied by the electrodes into elements, and ejecting electrons present in elements by means of the particle beam and collecting electrons ejected from the elements in electrodes, characterized in that is arranged to eject electrons present in electrodes s by applying to the electrodes a reflected particle beam from reflection on at least one element of an incident particle beam.
- the device is arranged to conduct a test sequence of the electrical isolation between two elements by carrying out the following operations: carrying a first element to a first electrical potential by ejecting electrons present in the first element, carrying a second element at a second electrical potential lower than the first electrical potential by injecting electrons into the second element, and measuring the electrical potential of at least one of the elements after a lapse of time.
- the device is arranged to conduct a test sequence or measurement of a resistance, a capacitance or self-inductance by performing the following operations: pulling an element towards a first electrical potential by ejecting electrons from the first element, pulling a second element towards a second electrical potential lower than the first electrical potential, injecting electrons into the second element, and measure an electrical charge flowing between the first and the second element.
- the electron discharge and collection plate comprises a plurality of electrodes of the same structure, each of which can form an electron discharge electrode in an electron withdrawing element or electrode ejected from an element, and comprises, between the electrodes, spacings allowing a portion of the particle beam to pass through the discharge plate and electron collection and reach elements.
- the electrodes of the discharge and electron collection plate comprise a surface treatment in order to maximize the ejection of electrons present in the electrodes under the effect of the reflected particle beam.
- the discharge and electron collection plate comprises electrodes comprising a grid of thin conductors.
- the discharge and electron collection plate comprises electrodes comprising a pad of an electrically conductive material.
- the electron discharge and collection plate comprises the electrodes arranged in a matrix manner, in rows and in columns.
- the discharge and electron collection plate comprises electrodes parallel to each other.
- the electron discharge and collection plate comprises electrodes in the form of rectilinear strips.
- the device comprises an electrically insulating separator plate disposed or disposed between the electron discharge and collection plate and the elements, the separator plate comprising orifices at locations corresponding to injection or electron collection points and forming electron circulation corridors and particle beam channeling.
- the device comprises at least one source of an ultraviolet light beam.
- an electrical element is at least one of the following elements: an electrical conductor, an electrical component, an electronic component, a terminal of an electrical conductor or a terminal of an electrical or electronic component.
- FIGS. 2A and 2B respectively illustrate a method according to the invention of injecting electrons into a conductor and a process for ejecting electrons present in the conductor
- FIG. 3 illustrates a method according to the invention for channeling a stream of electrons
- FIG. 4 illustrates the implementation of a continuity test by means of the method according to the invention
- FIG. 5 represents a first embodiment of a discharge and collection plate according to the invention, and also represents in the form of blocks a control and measuring device of a test device according to the invention,
- FIG. 6 illustrates an example of use of the discharge and collection plate of FIG. 5 for the implementation of a continuity test
- FIG. 7 represents a second embodiment of a plate of FIG. discharge and collection according to the invention
- - Figure 8 shows a third embodiment of a discharge plate and collection according to the invention.
- FIG. 2A is a sectional view illustrating a method according to the invention of injecting electrons into a conductor to be tested.
- Figure 2B is a sectional view illustrating a method of ejecting electrons present in the conductor.
- the second method is in itself conventional, but its combination with the first form an aspect of the invention.
- Both methods are applied here to a conductor 10 arranged on an insulating substrate 12 of an interconnect carrier comprising various other conductors (not shown). They are implemented by means of a plate 20 for discharging and collecting electrons and a beam of particles BI generating a photoelectric effect, here a beam of ultraviolet light, in the presence of a primary vacuum (empty partial).
- the photoelectric impact zone, or test point is here a contact area 11 of the conductor 10 covered by a solder layer 13.
- the discharge and collection plate 20 comprises a silica support plate 21 transparent or partially transparent to ultraviolet rays, whose front face (conductive side 11) comprises a plurality of electrodes 22, 22 '.
- the electrodes 22, 22 ' are individually accessible for the application to each electrode of an electric potential.
- the incident light beam BI is applied to the rear face of the support plate 21, at an angle of incidence which is here perpendicular to the support plate 21, and passes through the support plate 21 to reach the photoelectric impact zone.
- the support plate 21 is kept parallel to the substrate 12, so that the conductor 10 is at a distance d from the electrodes 22, 22 'along an axis perpendicular to the plane of the substrate.
- the electrodes 22, 22 ' are here of the same structure and of the same thickness, each being formed by a thin layer of metal of a thickness of the order of a few hundred nanometers, deposited on the support plate 21.
- the electrodes 22, 22 ' may be square in shape ( Figures 5 and 6) and arranged in a matrix manner (in rows and columns) or form parallel strips ( Figure 7).
- the size of The electrodes and their spacing are chosen so that the incident beam BI partially passes through the discharge and collection plate 20 and reaches the target zone.
- an arrangement of the electrodes 22, 22 'considered satisfactory is such that approximately 30 to 60% of the incident beam BI reaches the impact zone, the remainder of the beam BI being reflected or absorbed by the rear face of the electrodes 22, 22 '.
- the electrodes 22, 22 ' are here of a width smaller than that of the contact area 11, so that several electrodes are in the immediate vicinity of the photoelectric impact zone (electrodes referenced 22) while others are outside the impact zone (electrodes referenced 22 ').
- the electrodes 22 are brought to an electrical potential Vn less than the electrical potential Vf of the conductor 10, which is a floating potential.
- the potential Vf may be initialized beforehand to a known value greater than Vn.
- the conductor 10 may for example be grounded or brought to a positive potential by various known means (carbon brush, ion bombardment) or by means of the method shown in Figure 2B and described below.
- the electric potential Vn is imposed by a negative or zero voltage (ground potential) if the floating potential Vf is a positive potential.
- the incident light beam BI is reflected on the range 11 of the conductor 10 to form a reflected light beam BR which is reflected back onto the electrodes 22.
- the reflected light beam BR comprises about 30 to 85% of the intensity of the incident light beam BI, depending on the material forming or covering the target areas, materials such as gold having the highest reflection coefficients found.
- the second photoelectric effect is produced by the impact of the reflected beam BR on the electrodes 22 and leads to the ejection of "e2" type electrons which are projected onto the conductor 10 by the repulsive electric field and are absorbed by it.
- the conductor 10 is negatively charged (charging its parasitic capacitance) and its electrical potential tends towards that of the electrodes 22.
- the conductor 10 is at the potential Vn.
- the duration of the process is typically of the order of a few nanoseconds and determines the duration of a photoelectric shot.
- the electrodes 22 facing the range 11 of the conductor 10 are brought to an electrical potential Vp greater than the electrical potential Vf of the conductor 10. If necessary, the potential Vf is initialized to a value less than Vp, for example the potential of mass or the potential Vn obtained by means of the method of electron injection described above.
- the impact of the incident beam BI on the range 11 of the conductor 10 causes the ejection of electrons of type "el” which are "sucked” by the electrodes 22 due to the attractive electric field, while the impact on the electrodes 22 of the reflected light beam BR leads to the ejection of electrons of type "e2" which are returned to the electrodes 22 by the attractive electric field.
- the conductor 10 loses electrons and its electrical potential tends towards the positive potential Vp of the electrodes 22.
- the driver is at potential Vp.
- an electrode 22 according to the invention forms indifferently a discharge electrode (FIG. 2A) or a collection electrode (FIG. 2B) according to the potential difference imposed between the electrode and the conductor to be tested.
- a discharge electrode FIG. 2A
- a collection electrode FIG. 2B
- the electron injection method according to the invention can, however, be implemented in isolation, for example for the C4-to-BGA type conductor test, by placing the BGA test points on a connected nail bed. to a reference potential and by performing an electron injection on the C4 test points.
- the respective efficiencies of the electron injection method and the electron ejection process be balanced.
- the advantage of balancing yields is to obtain the same ability to adjust the electric potential of a driver in a period of time corresponding to the duration of a shot, whether it is a adjustment by injection or electron ejection.
- the incident light beam BI reaching the conductor 10 has 50% of the intensity of the initial light beam applied to the support plate 21 due to losses by reflection on conductive areas of the collector, particularly the rear face of the electrodes and various interconnection elements of the electrodes described below.
- the target conductor and the electrodes have reflection coefficients close to the order of 0.5. Under these conditions, the direct photoelectric effect involves 25% of the energy of the initial light beam while the indirect photoelectric effect involves 12.5% of the energy of the initial light beam.
- the equilibration of the yields can be obtained by applying to the electrodes 22 a surface treatment, for example a layer electrically conductive antireflection. It may be a stack of metal or semiconductor layers performing an anti-reflective function, even imperfect. Instead of increasing the absorption of the ultraviolet beam with an antireflection or surface absorber, it is also possible to maximize the electron ejection by providing a coating layer having a low work function of its electrons. or even roughening the surface of the electrodes, to increase their interface (boundary surface) with the external environment.
- a surface treatment for example a layer electrically conductive antireflection. It may be a stack of metal or semiconductor layers performing an anti-reflective function, even imperfect.
- Yet another solution is to increase the energy of the incident beam during the implementation of the indirect photoelectric effect injection method of electrons, in other words to modulate the energy of the beam of particles or of light according to that we eject or inject electrons into a conductor.
- the various phenomena involved in the technical effect obtained are presented here in a simplified manner. The study of these phenomena and their mathematical modeling, to obtain parameters making it possible to optimize the implementation of the invention for obtaining similar yields between the direct photoelectric effect and the indirect photoelectric effect, make include the notion of solid angle.
- One objective to be achieved to optimize the implementation of the invention is to form an electron circulation corridor to prevent them from reaching neighboring conductors.
- the electrodes 22 'in the vicinity of the useful electrodes 22 are brought to a highly repulsive electric potential Vr, for example -10V if the potentials Vn and Vp are respectively of the order from 0 to -5 V and from 0 to + 5V.
- Vr highly repulsive electric potential
- an electron circulation corridor is formed delimited by a highly repulsive electric field which surrounds the photoelectric impact and electron circulation zone.
- a separating plate 30 is disposed between the substrate 12 and the discharge and collection plate 20.
- a separating plate 30 is made of an electrically insulating material, for example epoxy, and has orifices 31 at locations corresponding to the test points of the interconnection support, the points of injection or ejection of electrons.
- Such a separator plate has various advantages: it prevents the electrons ejected from the range 11 or the electrodes 22 from reaching the neighboring conductors or reaching the electrodes 22 'neighbors, and as such it replaces the highly repulsive electric field described plias high,
- a driver isolation test sequence 10 is performed in a conventional manner but using the direct photoelectric effect and / or the indirect photoelectric effect.
- the insulation test sequence is for example carried out as follows: 1) the conductor 10 is first brought to a reference potential, for example ground, in a conventional manner
- the electrodes 22 are brought to the potential of the mass and a firing of ultraviolet light is triggered.
- the direction of circulation of the electrons to bring the conductor 10 to the potential of the mass depends on its initial potential. In other words, it is not necessary to be concerned about whether the result is caused by the direct or indirect photoelectric effect.
- the second conductor 10 ' is grounded, for example in the same way as the conductor 10, and is left floating.
- the electrons circulating between the electrodes 22 and the conductor 10 'during step 4) are counted to determine the quantity of electricity exchanged Q. If the quantity of electricity measured Q corresponds to a reference quantity of electricity Qr
- the measured quantity Q and the duration of the period of time make it possible to determine the insulation resistance between the conductors 10, 10 'with reference to graphs, and decide whether it is above or below a rejection threshold of the interconnect support.
- the isolation being practically tested between each driver and all the other drivers of an interconnection medium, this The method of testing insulation between two conductors is intended to be iteratively applied to all pairs of conductors to be tested on a support.
- the isolation of a conductor from a group of conductors can be tested globally and iteratively. For example, all the conductors are initialized to ground and a first conductor is brought to the voltage Vp and tested against the others. If its voltage remains equal to Vp, the driver is well isolated.
- a continuity test sequence of the conductor 10 is illustrated in FIG. 4.
- the conductor 10, shown in longitudinal section, has at one of its ends the contact pad 11 already described and has at its other end a contact pad 11 '.
- the electrodes facing the range 11 are designated 22a and those opposite the end 11 'are designated 22b.
- the test sequence is conducted here using the separator plate 30, which has an electron circulation port 31 between the pad 11 and the electrodes 22a and an electron circulation port 31 'between the pad 11' and the electrodes 22b.
- the electrodes 22a are brought to the potential Vn (for example OV) by a voltage source VGEN1, via an acquisition and measurement circuit AMCT1.
- the electrodes 22b are brought to the potential Vp (for example 5V) by a voltage source VGEN2, via an acquisition and measurement circuit AMCT2.
- Vp for example 5V
- the test sequence also makes use of two sources S11, S2 of ultraviolet light and two motor mirrors M1, M2 whose orientation is controlled by a control and measurement unit CMJ.
- the AMCT1, AMCT2 circuits are also connected to the CMU for the evaluation of the measurement results.
- the source S1 provides an incident light beam BI1 which is sent by the mirror M1 to the range 11 and the source S2 provides an incident light beam BI2 which is sent by the mirror M2 over the range 11 '.
- the range 11 is pulled towards the potential Vh by indirect photoelectric effect (injection of electrons) while the range 11 'is pulled towards the potential Vp by direct photoelectric effect (ejection of electrons), and electrons circulate in the conductor (schematized by a current I whose direction is the opposite of the direction of circulation of the electrons).
- the electric charge Q collected by the range 11 ' is preferably measured in differential mode by the circuits AMCT1, AMCT2 (respectively load injected in the range 11 and load extracted from the range 11') in order to detect any parasitic phenomena which could cause loss and / or injection of electrical charges into the test loop. Charts developed during a calibration phase of the device allow the CMQ unit to deduce the value of the series resistor R of the conductor 10, which is a function of the collected charge.
- this method can be exploited as a resistance measuring method, independently of the conductor test, for example for the measurement of resistive components.
- the invention also applies to the testing of electrical components or to the measurement of their electrical characteristics (resistors, capacitors and self-inductances).
- electrical components can be tested in an isolated configuration or in being fixed on an interconnection support.
- the ultraviolet beam generating a photoelectric effect can be applied directly to the terminals of components to be tested or to interconnecting conductive tracks to which these components are connected (so-called "in situ" test, once the components are mounted).
- the invention is also not limited to the testing of passive components and can also be applied to the testing or measurement of active electronic components. It is well known that an active component is modeled as a set of passive components, a MOS transistor being for example modeled in a sum of capacities and resistances.
- the injection / extraction of electrons on terminals of an active component makes it possible to determine the electrical characteristics of the component.
- the injection / extraction of electrons in passive or active components may further be effected by means of a discharge and collection plate having shaped electrodes adapted to the component terminals, especially surface mount components (SMDs). ).
- FIG. 5 shows in block form the general architecture of a test device 40 according to the invention.
- the device 40 comprises the discharge and collection plate 20, the CMU control and measurement unit, for example a microcontroller, and various peripheral devices of the CMU unit, namely: the ultraviolet light sources Sl, S2 previously described (not shown in the figure), the motor mirrors Ml, M2 previously described (not shown in the figure),
- VGEN3 for supplying the repulsive voltage Vr (when the separator plate is not used)
- the decoder CDEC1 is powered electrically by the generator VGEN1, through the circuit, AMCT1.
- the decoder CDEC2 is powered electrically by the generator VGEN2, via the AMCT2 circuit, and the CDEC3 decoder is electrically powered by the VGEN3 generator.
- the discharge and collection plate 20 comprises a plurality of electrodes 22 arranged in rows and columns, each having a line rank "i" and a column rank "j". Four electrodes 22 only are shown in the figure for the sake of simplicity.
- Each electrode 22 of rank i, j comprises:
- a transistor-switch 221 whose control gate is connected to an output of the decoder IDEC1 via a line selection line LSELIi, the drain of which is connected to an output of the decoder CDEC1 via a column selection line CSELIj, the source of which is connected to the electrode 220,
- a transistor-switch 222 whose control gate is connected to an output of the decoder LDEC1 via a line selection line LSEL2i, the drain of which is connected to an output of the decoder CDEC2 via a column selection line CSEL2J, the source of which is connected to the electrode 220; a transistor-switch 223 whose control gate is connected to an output of the decoder LDEC1 via a selection line line LSEL3i, whose drain is connected to an output of the decoder CDEC3 via a column selection line CSEL3J, and whose source is connected to the electrode 220,
- a measurement capacitor CS connecting the electrode 220 to a reference potential, here the voltage Vr supplied on the line CSEL3J by the decoder CDEC3.
- This capacitance CS is, for example, the parasitic capacitance of one of the transistors 221 to 223, or the resulting parasitic capacitance formed by the parasitic capacitances of each of the transistors. It forms a means of temporary storage of the charges collected during a shot, and allows the circuits AMCT1, AMCT2 measure quantities of electricity exchanged by photoelectric effect. Thus, once the firing is completed, the stored charge is emptied by grounding the conductor to which it is connected, to recover and measure the charge Q taken during the firing, which, as indicated above, makes it possible to deduce a series resistance value.
- the unit CMU supplies the following signals to the decoder IiDEC1: a line address signal ADL1 which designates the lines T 1 S 1 RTiI to be activated to make pass transistors-switches connected to these lines,
- a line address signal ADL2 which designates the lines LSEL2 to be activated in order to make the transistorswitch connected to these lines pass
- a line address signal ADL3 which designates the lines LSEL3 to be activated in order to make the transistorswitch connected to these lines pass
- the CMU also provides the following signals to the CDEC1 to CDEC3 decoders:
- a column address signal ADCl which designates the lines CSEL1 to receive the voltage Vp
- a column address signal ADC2 which designates the lines CSRT.2 to receive the voltage Vn
- a column address signal ADC3 which designates the lines CSEL3 to receive the voltage Vr .
- Such multiplexed addressing using the voltages Vp, Vn, Vr as column selection signals, allows the unit CMQ to independently apply to each of the electrodes one of the aforementioned voltages.
- FIG. 6 shows a view from above of an example of selection of electrodes 22 for applying a continuity test to a conductor of the C4-to-C4 type.
- the conductor is under the discharge and collection plate 20 and is shown in dashed lines, by transparency. It has two end areas C41, C42 provided with solder microbeads (not visible in the figure) and forming two points of contact. test for the continuity test.
- the electrodes are shown schematically in the form of squares, without taking into account the selection lines and transistors described above (the actual spacing between the useful metal electrodes 220 thus being greater than that which appears in FIG. 6).
- the CMJ unit applies to the decoders LDEC1 and CDEC1 to CDEC3 address signals such as:
- the row electrodes (2, 2), (2, 3), (3, 2), (3, 3) lying under the range C41 receive the voltage Vp (vertical hatch), in order to bring the range C41 to the voltage Vp by direct photoelectric effect, - the row electrodes (4, 6), (4, 7), (5, 6), (5, 7), (6, 6), (6, 7) extending in whole or in part below the range C41 receive the voltage Vn (transverse hatch) to bring the C41 range to the voltage Vn by indirect photoelectric effect, and
- FIG. 7 shows a discharge and collecting plate 200 according to the invention in which the previously described electrodes are replaced by conductive strips 230-1, 230-2, ... 230-i parallel to each other and here in rectilinear form. zigzag, "Z" and “S” shaped bands can also be provided. The structure of the discharge and collection plate is thus considerably simplified.
- the bands 230-i are controlled in voltage and in selection by a line decoder LDEC2 receiving only the voltages Vp and Vn as voltages to be multiplexed, and receiving only two address signals ADL1, ADL2 respectively denoting the bands to receive the voltage Vp and the strips to receive the voltage Vn.
- the transport of repulsive voltage Vr is thus suppressed, which implies the use of an electrically insulating separator plate.
- the discharge and collection plate 200 allows, as the previous one, to conduct insulation and continuity tests on all types of conductors. For example, consider that an insulation test must be conducted between two conductive pads, for example of C4 type, belonging to different equipotentials (conductors), designated C43 and C44 in Figure 7. To conduct this test , the conductive strip 230-2 passing above the range C43 is raised to the potential Vn, while the conducting strips 230-6, 230-7 wholly or partly above the range C44 are brought to the voltage Vp. A first firing of ultraviolet light is performed above the C43, C44 ranges to bring them respectively to the voltage Vn and the voltage Vp.
- the conductive strip 230-2 is brought to the potential Vp, an ultraviolet light is fired above the C43 range and is accompanied by a count of the amount of electricity supplied by the VGEE generator. -Nl, to determine, as indicated above, whether the C43 range is still at potential Vn or not.
- FIG. 8 shows a discharge and collection plate 300 also comprising conductive strips 330-1, 330-2, 330-3, 330-4, 330-5, 330-6 ... 330 -i parallel to each other and rectilinear.
- the bands 330-i are driven here in voltage and in selection by a line decoder LDEC3 receiving the three voltages Vp, Vn, Vr and three address signals ADL1, ADL2, ADL3 respectively denoting the bands to receive the voltage Vp, the strips to receive the voltage Vn and the strips to receive the repulsive voltage Vr.
- FIG. 8 also illustrates an isolation test conducted between two conductive pads C53, C54 (the equipotentials connecting the conductive pads being here arranged at an angle relative to the longitudinal axis of the conductive strips).
- the conductive strip 330-3 passing over the range C53 is raised to the potential Vn
- the conductive strip 330-4 partially passing above the range C53 and partially above the range C54 is brought to the repulsive potential Vr
- the conductive strips 330-5, 330-6 passing over the range C54 are brought to the potential Vp.
- a first light shot ultraviolet is performed above the C53, C54 ranges to bring them respectively to the voltage Vn and the voltage Vp.
- the conductive strip 330-3 is taken to the potential Vp
- an ultraviolet light is fired above the C53 range and is accompanied by a count of the amount of electricity to determine if the range C53 is still at potential Vn or not.
- the present invention is capable of various other alternative embodiments, in particular as regards the implementation of continuity or isolation tests, the production of the collection plate and discharge, the realization of control means, acquisition and measurement described above, and the choice of test voltages Vp, Vn, Vr.
- the collection and discharge electrodes are arranged in a matrix manner, these may have various other forms than those described above, in particular a round, triangular shape or any parallelogram shape.
- an arrangement of the electrodes on a support plate parallel to the interconnection substrate is preferred in the context of an industrial implementation of the method of the invention, such an arrangement is in no way imperative to obtain the invention. the intended technical effect.
- the electrodes may for example comprise a cylindrical portion or a metal frustoconical portion extending towards the conductors, so as to form themselves electron circulation corridors. They may also be flat as previously described but oriented at a non-zero angle relative to the plane of the interconnection support. Also, although it has been indicated in the foregoing that the width (or diameter) of the electrodes is smaller than the smallest width of a conductor to be tested, to create gaps allowing the incident light beam to reach other possible solutions are the conductor, in particular larger-surface electrodes having apertures or windows passing through the incident light beam.
- discharge and collection plates According to the invention, although initially intended for joint implementation of the indirect photoelectric effect and the direct photoelectric effect, they form in themselves independent inventions having their own advantages.
- these discharge and collection plate structures according to the invention can also be used to implement test or measurement methods in which the indirect photoelectric effect is not used (or in which the photoelectric effect direct is not used), the injection of electrons (or electron extraction) is done for example by means of a bed of nails, to any other method, including electron injection methods described in WO 01/38892.
- the discharge and collection plate structures according to the invention are used as collection plates only (or as discharge plates only), but the advantages they offer remain (shape and arrangement of the electrodes in particular).
- the present invention is also susceptible of various applications and is not limited to bare interconnection media testing as discussed above.
- the invention makes it possible, in particular, to test or measure printed circuits equipped with components, to test or measure passive and active electrical and electronic components, to test terminals of components, etc.
- the invention also allows the so-called “in situ” test, that is to say the measurement of the value of electronic components mounted on an interconnection support
- the target areas for the photoelectric effect being either the terminals of the components themselves or tracks or ranges connected to these terminals. It also allows the test of the conductors present in the silicon integrated circuits, by firing on input / output contacts connected by equipotentials, as well as the test of the conductors present on flat screens and generally the test of any conductor or component offering test points accessible from the outside.
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- General Engineering & Computer Science (AREA)
- Health & Medical Sciences (AREA)
- Computer Vision & Pattern Recognition (AREA)
- Electromagnetism (AREA)
- Toxicology (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Tests Of Electronic Circuits (AREA)
- Testing Or Measuring Of Semiconductors Or The Like (AREA)
Abstract
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2007553641A JP2008529023A (ja) | 2005-02-04 | 2006-01-24 | 間接光電効果を使用して電気要素を試験するための方法 |
EP06709154A EP1896862A1 (fr) | 2005-02-04 | 2006-01-24 | Procede de test d'elements electriques utilisant un effet photoelectrique indirect |
US11/833,394 US20080018349A1 (en) | 2005-02-04 | 2007-08-03 | Method for testing electrical elements using an indirect photoelectric effect |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR0501094 | 2005-02-04 | ||
FR0501094A FR2881833B1 (fr) | 2005-02-04 | 2005-02-04 | Procede de test d'elements electriques utilisant un effet photoelectrique indirect |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US11/833,394 Continuation US20080018349A1 (en) | 2005-02-04 | 2007-08-03 | Method for testing electrical elements using an indirect photoelectric effect |
Publications (1)
Publication Number | Publication Date |
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WO2006082294A1 true WO2006082294A1 (fr) | 2006-08-10 |
Family
ID=35046948
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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PCT/FR2006/000155 WO2006082294A1 (fr) | 2005-02-04 | 2006-01-24 | Procede de test d'elements electriques utilisant un effet photoelectrique indirect |
Country Status (8)
Country | Link |
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US (1) | US20080018349A1 (fr) |
EP (1) | EP1896862A1 (fr) |
JP (1) | JP2008529023A (fr) |
KR (1) | KR20070110059A (fr) |
CN (1) | CN101116001A (fr) |
FR (1) | FR2881833B1 (fr) |
TW (1) | TW200633109A (fr) |
WO (1) | WO2006082294A1 (fr) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2927703A1 (fr) * | 2008-02-14 | 2009-08-21 | Beamind Soc Par Actions Simpli | Procede de test de conducteurs electriques par photoelectricite, a courant de test non nul. |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
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KR102506803B1 (ko) * | 2018-11-23 | 2023-03-07 | 삼성전자주식회사 | 배선 기판 테스트 방법 및 이를 수행하기 위한 장치 |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4967152A (en) * | 1988-03-11 | 1990-10-30 | Ultra-Probe | Apparatus including a focused UV light source for non-contact measurement and alteration of electrical properties of conductors |
EP0424270A2 (fr) * | 1989-10-20 | 1991-04-24 | Digital Equipment Corporation | Essai stimulé avec un laser émitteur électronique |
WO2001038892A1 (fr) * | 1999-11-26 | 2001-05-31 | Christophe Vaucher | Test electrique de l'interconnexion de conducteurs electriques sur un substrat |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6369590B1 (en) * | 1999-01-14 | 2002-04-09 | Maniatech Incorporated | Apparatus and method using photoelectric effect for testing electrical traces |
FR2794748B1 (fr) * | 1999-06-10 | 2001-09-21 | Corning Sa | Naphtopyranes anneles en c5-c6 avec un cycle c6 de type lactame et les compositions et matrices (co)polymeres les renfermant |
-
2005
- 2005-02-04 FR FR0501094A patent/FR2881833B1/fr not_active Expired - Fee Related
-
2006
- 2006-01-24 JP JP2007553641A patent/JP2008529023A/ja active Pending
- 2006-01-24 WO PCT/FR2006/000155 patent/WO2006082294A1/fr active Application Filing
- 2006-01-24 KR KR1020077020187A patent/KR20070110059A/ko not_active Application Discontinuation
- 2006-01-24 EP EP06709154A patent/EP1896862A1/fr not_active Withdrawn
- 2006-01-24 CN CNA2006800032631A patent/CN101116001A/zh active Pending
- 2006-01-26 TW TW095103192A patent/TW200633109A/zh unknown
-
2007
- 2007-08-03 US US11/833,394 patent/US20080018349A1/en not_active Abandoned
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4967152A (en) * | 1988-03-11 | 1990-10-30 | Ultra-Probe | Apparatus including a focused UV light source for non-contact measurement and alteration of electrical properties of conductors |
EP0424270A2 (fr) * | 1989-10-20 | 1991-04-24 | Digital Equipment Corporation | Essai stimulé avec un laser émitteur électronique |
WO2001038892A1 (fr) * | 1999-11-26 | 2001-05-31 | Christophe Vaucher | Test electrique de l'interconnexion de conducteurs electriques sur un substrat |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2927703A1 (fr) * | 2008-02-14 | 2009-08-21 | Beamind Soc Par Actions Simpli | Procede de test de conducteurs electriques par photoelectricite, a courant de test non nul. |
Also Published As
Publication number | Publication date |
---|---|
CN101116001A (zh) | 2008-01-30 |
JP2008529023A (ja) | 2008-07-31 |
TW200633109A (en) | 2006-09-16 |
US20080018349A1 (en) | 2008-01-24 |
KR20070110059A (ko) | 2007-11-15 |
FR2881833B1 (fr) | 2007-04-20 |
EP1896862A1 (fr) | 2008-03-12 |
FR2881833A1 (fr) | 2006-08-11 |
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