CN106091907A - A kind of solder joint displacement real non-destructive monitoring method - Google Patents
A kind of solder joint displacement real non-destructive monitoring method Download PDFInfo
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- CN106091907A CN106091907A CN201610388608.5A CN201610388608A CN106091907A CN 106091907 A CN106091907 A CN 106091907A CN 201610388608 A CN201610388608 A CN 201610388608A CN 106091907 A CN106091907 A CN 106091907A
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- solder joint
- measured
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- electric current
- copper deposits
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
- G01B7/02—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness
Abstract
The invention provides a kind of solder joint displacement real non-destructive monitoring method, relate to encapsulation technology field, including: selected solder joint to be measured；Selected four tested points in solder joint the first side copper deposits to be measured and the second side copper deposits；From four pairs of tested points, arbitrarily selected two apply point to as electric current, and using remaining two to as differential pressure measurement point；Arbitrarily select to apply electric current between 2 be not in the copper deposits of the same side in two pairs of electric currents apply point, and measure two voltage differences to being not between any two points in the copper deposits of the same side in differential pressure measurement point；In step s 4 two pairs of electric current applying points do not apply to apply electric current between 2 of electric current, and measure two voltage differences to being not between any two points in the copper deposits of the same side in differential pressure measurement point；It is calculated the displacement on three directions of solder joint to be measured based on measured value.It uses accuracy voltage measurement apparatus, and the voltage difference of repetitive measurement solder joint to be measured all angles realizes the purpose monitoring solder joint to be measured.
Description
Technical field
The present invention relates to encapsulation technology field, particularly relate to a kind of solder joint displacement real non-destructive monitoring method.
Background technology
At present, the encapsulation of electronic product relies on the interconnection of substantial amounts of solder joint.Most solder joint is during the military service of product
Will bear bigger power and the cyclic loading of heat, As time goes on the result of cyclic loading accumulates often in solder joint
Play stagnant plastic deformation (viscoplastic deformation).When deformation runs up to a certain degree when, crackle will be
Solder joint germinates and then extends to destroy completely, and the destruction of solder joint often leads to the inefficacy of whole system.Butt welding at present is pointed out
The technical barrier of bad prognosis (prognostic) is in the monitoring in real time of the stagnant plastic deformation of butt welding point, if the change of solder joint
Shape amount can be by relatively accurate measurement before crack initiation, then the time that crackle occurs in theory will be by relatively accurate pre-
Surveying, this is to shortening the time of solder joint accelerated test, the efficiency of improving product screening test, reducing the maintenance of product under truth
The safety of replacement frequency and increase key position solder joint plays vital effect.
The method of existing measurement solder joint displacement includes: section electronic microscope photos, X-ray transmission and nanometer CT etc..But,
All there are some problems in these measuring methods: section electronic microscope photos needs to destroy whole package system, and is only able to detect one
The displacement of individual side, can not realize monitoring in real time.X-ray transmission is merely able to characterize the shear displacemant of solder joint, and precision is relatively
Low, and can not realize monitoring in real time.Nanometer CT method can measure the displacement in all directions of solder joint, and precision is the highest,
But can not realize equally monitoring in real time, and price is the highest.
Generally speaking, the shortcoming of prior art is: 1). cannot be carried out real-time (in-situ) displacement prison of solder joint displacement
Survey；2). during only solder joint is on active service, the displacement energy of a time point is measured to, and the prognosis for the life-span does not has big help；3).
Prior art almost cannot detect the tired displacement of multiple solder joint simultaneously, or needs great workload to reach this purpose；
4). it is difficult to the electrical detection integration of equipments with other, increases the detection difficulty the most tediously long testing time.
Summary of the invention
For the problems referred to above, it is desirable to provide a kind of solder joint displacement real non-destructive monitoring method, it uses precision electricity
Pressure measuring device, the voltage difference of repetitive measurement solder joint to be measured all angles realizes the purpose to solder joint real non-destructive to be measured monitoring.
The technical scheme that the present invention provides is as follows:
A kind of solder joint displacement real non-destructive monitoring method, specifically includes:
S1 selectes solder joint to be measured, and obtains the measuring resistance of described solder joint to be measured；
S2 respectively in the first side copper deposits and the second side copper deposits of described solder joint to be measured selected four mutual right
The tested point claimed；
S3 arbitrarily selected two applies point to as electric current, and using remaining two to as pressure reduction from described four pairs of tested points
Measure point；
S4 arbitrarily selects to apply between 2 be not in the copper deposits of the same side in described two pairs of electric currents apply point
Electric current, and measure two voltage differences to being not between any two points in the copper deposits of the same side in differential pressure measurement point；
S5 two pairs of electric current applying points in step s 4 do not apply between 2 of electric current, apply electric current, and measure two to pressure
The voltage difference being not between any two points in the copper deposits of the same side in difference measurements point；
S6 is calculated institute based on the standard electric resistance obtained in the measured value in step S4 and step S5 and step S1
State the displacement on tri-directions of solder joint X/Y/Z to be measured, it is achieved the monitoring to described solder joint to be measured.
It is further preferred that in step s 2, four tested points in described first side copper deposits and described second side
Four tested points in copper deposits are the most symmetrical based on described solder joint to be measured.
It is further preferred that in step s3, the electric current in the first side copper deposits applies point and the second side copper deposits
In electric current apply point for asymmetric point.
It is further preferred that in step s 6, specifically include:
S61 applies the current value on point based on the voltage difference measured in step S4 with being applied to two electric currents, is somebody's turn to do
Electric current applies two resistance values on direction；
S62 applies the current value on point based on the voltage difference measured in step S5 with being applied to two electric currents, is somebody's turn to do
Electric current applies two resistance values on direction；
S63 is based on the standard electric resistance obtained in the resistance value obtained in step S61 and step S62, step S1 and pre-
If operation method be calculated the displacement on described tri-directions of solder joint X/Y/Z to be measured.
It is further preferred that in step s 6, the resolution of the resistance obtained is measured less than 500n Ω.
It is further preferred that in step S4 and step S5, electric current is all to flow to the second side copper from the first side copper deposits
Sedimentary or electric current are all to flow to the first side copper deposits from the second side copper deposits.
In the technical program, in step S4 and step S5, the flow direction of electric current is identical, i.e. if in step S4,
The flow direction of electric current is for flow to the second side copper deposits from the first side copper deposits, and the most in step s 5, the flow direction of same electric current is also
For flowing to the second side copper deposits from the first side copper deposits.
The solder joint displacement real non-destructive monitoring method that the present invention provides, it is possible to bring following beneficial effect:
The method that the present invention provides utilizes high precision electro pressure measuring device (the resistance resolution recorded is less than 500n Ω), leads to
The voltage difference crossing each angle of the design of special multi-electrode, repetitive measurement solder joint to be measured (applies the side of electric current in point according to electric current
Pressure reduction between repetitive measurement differential pressure measurement point) to reach to measure the purpose of solder joint deformation.
It can be seen that the monitoring method that the present invention provides need not destroy whole encapsulation realizes the purpose of monitoring, belong to nothing
Damage method of testing；And the motility of voltage tester allow the invention to monitor simultaneously multiple solder joint to be measured (be in test or
In commission solder joint to be measured), to save outside the substantial amounts of measurement time, it is pre-that the Data-Link that measurement obtains greatly facilitates the life-span
Afterwards (prognosis).It addition, the monitoring method that the present invention provides can be with existing electrical testing hardware compatibility, whole test
Process can realize full automation, and displacement calculates convenient and swift, time-consuming while greatly reduce cost of labor.
Accompanying drawing explanation
Below by the way of the most understandable, accompanying drawings preferred implementation, to above-mentioned characteristic, technical characteristic,
Advantage and implementation thereof are further described.
Fig. 1 is chips Board level packaging structural representation of the present invention；
Fig. 2 is the relation schematic diagram in the present invention between solder joint displacement to be measured and resistance；
Fig. 3 is solder joint displacement real non-destructive monitoring method schematic flow sheet in the present invention；
Fig. 4 is single welding spot structure schematic diagram to be measured in the present invention.
Reference:
1-chip, 2-the first side copper deposits, 3-solder joint to be measured, 4-the second side copper deposits, 5-substrate,
E1～E4 is four tested points selected in the copper deposits of solder joint the first side to be measured；
F1～F4 is four tested points selected in the copper deposits of solder joint the second side to be measured.
Detailed description of the invention
The solder joint displacement real non-destructive monitoring method that the present invention provides is mainly for chip 1 Board level packaging as shown in Figure 1
Structure, in this encapsulating structure, by the first side copper deposits 2 on chip 1 surface to be packaged and second side on substrate 5 surface
It is subjected between copper deposits 4, it is achieved the connection between chip 1 to be packaged and substrate 5, wherein, the first side copper deposition
Scolding tin between layer 2 and the second side copper deposits 4 is above-mentioned solder joint to be measured.
In real work, the displacement of solder joint 3 to be measured, by partly constituting, is respectively as follows: in substrate 5 plane in both direction
Displacement Ux and Uy, and the displacement Uz (displacements on tri-directions of X/Y/Z) in vertical direction.In order to verify what the present invention provided
The feasibility of solder joint displacement real non-destructive monitoring method, we are for the displacement size on 3 three directions of solder joint to be measured and its electricity
Relation between resistance height is emulated, as in figure 2 it is shown, it can be seen that the resistance of solder joint to be measured 3 is along with being applied to
The change of this solder joint 3 upper stress to be measured changes, the resistance height of solder joint 3 the most to be measured displacement in three directions and solder joint
There is direct relation, and the direction of displacement also can be represented by the increase of resistance or reduction.Specifically, in fig. 2, abscissa x is
Being applied to the stress intensity on solder joint 3 to be measured, vertical coordinate y is the resistivity change with stress intensity of this solder joint 3 to be measured.Curve
The stress being applied on this solder joint 3 to be measured in A is tension force/pulling force, and in this curve, relation between the two is specially y=
1.3804x；The stress being applied on this solder joint 3 to be measured in curve B is shear stress, pass cording between the two in this curve
Body is y=0.5433x；The stress being applied on this solder joint 3 to be measured in curve C is stress in the vertical direction, between the two
In nonlinear change；The stress being applied on this solder joint 3 to be measured in curve B is distorting stress, and variation relation between the two is same
Sample is nonlinear change.
Based on result above, as it is shown on figure 3, the invention provides a kind of solder joint displacement real non-destructive monitoring method, this prison
Survey method specifically includes: S1 selectes solder joint 3 to be measured, and obtains the measuring resistance of solder joint 3 to be measured；S2 is respectively at solder joint 3 to be measured
Selected four symmetrical tested points in first side copper deposits 2 and the second side copper deposits 4；S3 appoints from four pairs of tested points
Meaning selected two applies point to as electric current, and using remaining two to as differential pressure measurement point；S4 appoints in two pairs of electric currents apply point
Meaning selects to apply between 2 be not in the copper deposits of the same side electric current, and it is same to being not in differential pressure measurement point to measure two
The voltage difference between any two points in the copper deposits of side；S5 two pairs of electric currents in step s 4 apply not apply electric current in point
Apply electric current between 2, and measure two and be not between any two points in the copper deposits of the same side in differential pressure measurement point
Voltage difference；S6 is calculated to be measured based on the standard electric resistance obtained in the measured value in step S4 and step S5 and step S1
Displacement on tri-directions of solder joint X/Y/Z, it is achieved the monitoring to solder joint 3 to be measured.
Specifically, in step sl, by present invention is mainly applied in chip board class encapsulation structure, gesture in the structure shown here
A fairly large number of solder joint must be included, therefore first we need selected solder joint 3 to be measured, and just survey before this solder joint 3 to be measured is on active service
Measure the measuring resistance of this solder joint 3 to be measured, in one embodiment, measuring resistance R of solder joint 3 to be measured0It is 100 μ Ω.At this
In be noted that for convenience, during the description of above method, we only have selected a solder joint 3 to be measured, but
It is in actual applications, the monitoring method using the present invention to provide can monitor multiple solder joint to be measured 3 simultaneously, therefore can basis
Needing selected any number of solder joint 3 to be measured, we are not specifically limited.
Both sides copper deposits (the first side copper in diagram is included by Fig. 1 it will be seen that each solder joint to be measured 3 both sides
Sedimentary 2 and the second side copper deposits 4), as shown in Figure 4, after we have selected solder joint 3 to be measured (in step s 2),
Selected four tested points in the first side copper deposits 2 and the second side copper deposits 4 the most respectively, as the survey of subsequent current voltage
Amount point.The calculating of measurement result for convenience, four tested points in the first side copper deposits 2 are (such as the E1/E2/E3/ in Fig. 4
Tetra-tested points of E4) with the second side copper deposits 4 in four tested points (such as tetra-tested points of the F1/F2/F3/F4 in Fig. 4)
The most symmetrical based on solder joint 3 to be measured.Specifically, symmetry said herein is specially the symmetry of upper-lower position, and the i.e. first side copper sinks
Tested point in tested point E1 in the lamination 2 and tested point F1 in the second side copper deposits 4 symmetry, the first side copper deposits 2
Tested point F2 in E2 and the second side copper deposits 4 is symmetrical, by that analogy.
After have selected tested point, in four pairs of selected tested points, select two immediately apply point (step to as electric current
S3), and using remaining two to as differential pressure measurement point.Such as select two couples of tested point E1/F1 and E2/F2 and apply as electric current
Point, the most accordingly select two to tested point E3/F3 and E4/F4 as differential pressure measurement point.
Then, in step s3, applying to select apply electric current at 2 point from the two pairs of electric currents selected, certainly, these are two years old
Point can not be selected in the same side, and the electric current of applying need to flow through solder joint 3 to be measured, and (electric current flows to another copper deposition from side copper deposits
Layer).For further, the electric current that the electric current in the first side copper deposits 2 applies in point and the second side copper deposits 4 applies point
For asymmetric point, e.g., in one embodiment, the tested point E3 in selected first side copper deposits 2 and the second side copper deposits 4
In tested point F2 apply point (now selecting two couples of tested point E2/F2 and E3/F3 to apply a little) as electric current as electric current；Separately
In one embodiment, the tested point E1 in selected first side copper deposits 2 and the tested point F2 conduct in the second side copper deposits 4
Electric current applies point (now selecting two couples of tested point E1/F1 and E2/F2 to apply a little) etc. as electric current.
After have selected electric current applying point and being applied with electric current, in two pairs of differential pressure measurement points, select two immediately not same
The two-point measurement voltage difference (step S4/S5) of side.As, in a specific embodiment, two pairs of selected electric currents apply point minute
Not Wei tested point E2/F2 and E3/F3, and between tested point E2 and tested point F3 apply electric current, measure tested point the most accordingly
The voltage difference between voltage difference and measurement tested point E4 and tested point F1 between E1 and tested point F4；And for example, concrete at one
In embodiment, two pairs of selected electric currents apply point and are respectively tested point E1/F1 and E3/F3, and at tested point E1 and tested point F3
Between apply electric current, measure the voltage difference between tested point E1 and tested point F4 the most accordingly and measure tested point E4 and to be measured
Voltage difference between some F2.
Measurement is over after voltage difference obtains corresponding data, in step s 6, based on the measurement in step S4 and step S5
The standard electric resistance obtained in value and step S1 is calculated the displacement on tri-directions of solder joint X/Y/Z to be measured, it is achieved treat
Survey the monitoring of solder joint 3 in step s 6.Specifically, always include in this step: S61 based on step S4 in measure voltage difference
Apply the current value on point with being applied to two electric currents, obtain this electric current and apply two resistance values on direction；S62 is based on step
The voltage difference measured in S5 applies the current value on point with being applied to two electric currents, obtains this electric current and applies two on direction
Resistance value；S63 is based on the standard electric resistance obtained in the resistance value obtained in step S61 and step S62, step S1 and presets
Operation method be calculated the displacement on tri-directions of solder joint X/Y/Z to be measured.It is noted that the essence in order to improve measurement
Degree, in the present invention, uses high-acruracy survey voltage measuring apparatus to measure the voltage difference between differential pressure measurement point, in terms of this meets
The resolution of the resistance value obtained is less than 500n Ω.
In a specific embodiment, it is assumed that two pairs of selected electric currents apply point and are respectively tested point E2/F2 and E3/F3,
Then tested point E1/F1 and E4/F4 is voltage measurement point.
When electric current tested point E3 from the first side copper deposits 2 flows to the tested point F2 in the second side copper deposits 4, this
Time, measure the voltage difference between tested point E1 and tested point F4, and be calculated corresponding resistor resistance, be designated as R_E3F2//
E1F4.With this, this tested point carrying out four times and measures, last calculated resistance is divided into for R_E3F2//E1F4, R_
E3F2//E4F1, R_E2F3//E1F4 and R_E2F3//E4F1.And then it is calculated tri-sides of X/Y/Z according to below equation
Dependent variable ε upwardsx、εyAnd εz:
Wherein, the k in formula is the strain sensitivity of material, and value usual for relatively thin metal material is 2；k2It is and electricity
Displacement in stream vertical direction and the coefficient of relationship of resistance, can be obtained by emulation.It can thus be seen that above-mentioned 4 unknown number εx、
εy、εz, and k1Can be obtained by solving equations, the most i.e. can obtain this solder joint 3 to be measured displacement in three directions
Ux, Uy and Uz.
In one embodiment, the actual displacement on 3 three directions of solder joint to be measured be respectively Ux=8um, Uy=-10um,
And Uz=9um, the displacement using this method to record is respectively Ux=10.2um, Uy=-12.7um and Uz=8.1um,
It can be seen that the value that the method that the present invention provides is measured differs the least with actual value, there is feasibility, it is possible to for reality
In application.
It should be noted that, above-described embodiment all can independent assortment as required.The above is only the preferred of the present invention
Embodiment, it is noted that for those skilled in the art, in the premise without departing from the principle of the invention
Under, it is also possible to making some improvements and modifications, these improvements and modifications also should be regarded as protection scope of the present invention.
Claims (6)
1. a solder joint displacement real non-destructive monitoring method, it is characterised in that described monitoring method specifically includes:
S1 selectes solder joint to be measured, and obtains the measuring resistance of described solder joint to be measured；
S2 respectively in the first side copper deposits and the second side copper deposits of described solder joint to be measured selected four symmetrical
Tested point；
S3 arbitrarily selected two applies point to as electric current, and using remaining two to as differential pressure measurement from described four pairs of tested points
Point；
S4 selects 2 points being not in the copper deposits of the same side in described two pairs of electric currents apply point, and applies electricity in-between
Stream, measures two voltage differences to being not between any two points in the copper deposits of the same side in differential pressure measurement point simultaneously；
S5 two pairs of electric current applying points in step s 4 do not apply between 2 of electric current, apply electric current, measure two equally to pressure reduction
Measure the voltage difference being not between any two points in the copper deposits of the same side in point；
S6 based on the standard electric resistance obtained in the measured value in step S4 and step S5 and step S1 be calculated described in treat
Survey the displacement on tri-directions of solder joint X/Y/Z, it is achieved the monitoring to described solder joint to be measured.
2. solder joint displacement real non-destructive monitoring method as claimed in claim 1, it is characterised in that
In step s 2, four tested points in described first side copper deposits are treated with four in described second side copper deposits
Measuring point is the most symmetrical based on described solder joint to be measured.
3. solder joint displacement real non-destructive monitoring method as claimed in claim 2, it is characterised in that
In step s 4, the electric current during the electric current in the first side copper deposits applies point and the second side copper deposits applies point for non-
Point of symmetry.
4. the solder joint displacement real non-destructive monitoring method as described in claim 1-3 any one, it is characterised in that in step S6
In, specifically include:
S61 applies the current value on point based on the voltage difference measured in step S4 with being applied to two electric currents, obtains this electric current
Apply the resistance value on direction；
S62 applies the current value on point based on the voltage difference measured in step S5 with being applied to two electric currents, obtains this electric current
Apply the resistance value on direction；
S63 is based on the standard electric resistance obtained in the resistance value obtained in step S61 and step S62, step S1 and default
Operation method is calculated the displacement on described tri-directions of solder joint X/Y/Z to be measured.
5. solder joint displacement real non-destructive monitoring method as claimed in claim 4, it is characterised in that in step s 6, measure
The resolution of the resistance arrived is less than 500n Ω.
6. the solder joint displacement real non-destructive monitoring method as described in claim 1-3 any one, it is characterised in that in step S4
With in step S5, electric current is all to flow to the second side copper deposits from the first side copper deposits or electric current is all from the second side copper deposition
Laminar flow is to the first side copper deposits.
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| CN201610388608.5A CN106091907B (en) | 2016-06-03 | 2016-06-03 | A kind of solder joint displacement real non-destructive monitoring method |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109918823A (en) * | 2019-03-15 | 2019-06-21 | 成都航空职业技术学院 | A kind of minute yardstick BGA welding spot structure parameter optimization method reducing distorting stress |
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| CN103234499A (en) * | 2013-03-28 | 2013-08-07 | 南车株洲电力机车有限公司 | Device and method for monitoring electrode displacement in resistance spot welding and resistance spot-welding equipment. |
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| JPS5719603A (en) * | 1980-07-11 | 1982-02-01 | Hitachi Ltd | Device for measuring corner |
| CN1766587A (en) * | 2005-10-13 | 2006-05-03 | 上海交通大学 | Real-time quality detection and alarm method for car body spot welding |
| CN201594083U (en) * | 2010-01-29 | 2010-09-29 | 首都师范大学 | On-line monitoring system for solder joint damage |
| CN101825580A (en) * | 2010-02-11 | 2010-09-08 | 上海交通大学 | Real-time detection method for resistance spot welding quality based on electrode displacement fluctuation |
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