CN101014847B

CN101014847B - Shear test device

Info

Publication number: CN101014847B
Application number: CN2005800269303A
Authority: CN
Inventors: 罗伯特·约翰·赛科斯
Original assignee: Dage Precision Industries Ltd
Current assignee: Dage Precision Industries Ltd
Priority date: 2004-08-10
Filing date: 2005-08-05
Publication date: 2011-04-06
Anticipated expiration: 2025-08-05
Also published as: CN101014847A; GB0417773D0

Abstract

Shear test apparatus for gold and solder balls of a semi-conductor substrate comprises a support element (21) on which is provided a piezo electric crystal (24) in the direct shear load path. The crystal (24) may have a shield (25). The interface between shield and crystal, and crystal and support element may include an epoxy resin layer to distribute force and retain the components as a unit.

Description

Shear test apparatus

Technical field

The present invention relates to be used for the equipment of semiconductor test, and more specifically in conjunction with the shear resistance of (bond), relate to test substrate and with device that its is electrically connected between the equipment of the intensity that combines (typical, the spherical deposit of part of scolder or gold).

Background technology

Semiconductor devices is very little, and is typical, from 0.2 square millimeter to 25 square millimeters.These devices have the position that is used for electric conductor is incorporated into it.Described position typically comprises the spherical deposit of the part of gold or solder flux, is referred to as soldered ball (ball), and in use it has the profile of oblate spheroid or low dome and at the diameter of 50-1000 mu m range.These for example are deposited on and form electric pathway between the printed circuit board (PCB) and chip, and direct Connection Element, perhaps can be incorporated into the conductor that himself is connected to another element.The grid-like array of many such soldered balls as rule can be provided on substrate.

Typically, discrete soldered ball is applied to substrate, and in the connection of another element, makes its backflow subsequently.

It is necessary that gold or scolder deposit are tested with the physical strength that combines between the substrate, is suitable and bond strength is enough with the proof associated methods.Since the size that these elements are very little, degree of accuracy and the very little power that will measure and deflection (deflection) that testing apparatus is located, and produced many difficulties.

Proposed by a cutter is applied to the shear resistance that the one side is tested this deposit.Be the friction of avoiding on the surface of substrate, swiping and causing, must regulate this cutter just in time on substrate surface owing to this cutter.Must critically control the height of cutter on substrate, typically, in ± 0.001mm, to provide force measurement accurately.

Known shear test apparatus comprises the machinery of the measuring head that has stayed surface and move with respect to this stayed surface in a controlled manner.This measuring head carries the anchor clamps (cartridge) that are exclusively used in the test that will carry out, and has a kind of in several interchangeable cutters on it.Typically, the suitable ball deposit that will test of its size of this cutter and/or shape.In use, the substrate that will test is attached to stayed surface, and drives this cutter with respect to ball deposit, and to carry out required test, this can be for example shearing test or back and forth testing fatigue.

Should be appreciated that typical cutter is very little, and the flexible member of one or more dynamometers (for example strainometer) is installed above therefore anchor clamps have.Thereby, by the deflection in the anchor clamps in the shearing force of measuring on the certain distance between cutter and ball deposit.

Therein cutter with the situation of the shock-testing of high-speed mobile before ball deposit contacts under, be difficult for detecting shearing force.This is that some is far away to a certain extent because strain gauged element is from cutter, and the inertia of anchor clamps has been sheltered the power that will measure.Typically, the speed of this test is enough high, so that tests before strainometer responds power on the cutter if having time and just be through with.

Summary of the invention

According to first aspect present invention, a kind of proving installation that is used for shear load is applied to the ball deposit of gold on the substrate or scolder is provided, this device comprises: support component, the piezoelectric crystal on this support component, this support component is suitable for through described crystal shear load being applied to ball deposit, therefore this crystal is placed under the strain, and make and send electric signal from it.

Preferably, this device further comprises the shielding that is used for this crystal, makes shear load be applied to this ball deposit through this shielding.

This shielding can comprise the protection surface that is applied directly to this crystal, perhaps can be mounted on this support component and is suitable for bearing against the cutter elements of (bear against) this crystal.Can arrange this cutter elements with this crystal of prestrain (pre-load) so that improve its stability.

For example by having the part spherical recess that is suitable for the part engagement of the circumference of this ball deposit, this shielding can be fit to the shape of the ball deposit that will test.

In a preferred embodiment, the interface between interface between support component and crystal and/or crystal and shielding comprises the power distribution layer, and it is suitable for providing basic uniform in-plane contact.This layer for example can comprise epoxy resin, and its distribution is flowing on each interface surface simultaneously, and solidifies after this device assembling, to guarantee to produce plane contact.Can avoid the Points And lines load by this way.

This layer only needs extremely thin, and only is enough to hold any misalignment that may occur.A special advantage of epoxy resin is that adjacent parts keep with also adhering each other, make this device become integrated.

This layer can also provide the electrical isolation to this crystal, perhaps, according to electrical pathways, can conduct electricity.

According to a second aspect of the invention, a kind of equipment is provided, it is used to calibrate the device that is suitable for shear load is applied to the ball deposit of gold on the substrate or scolder, this equipment comprises: have flat surfaces and with the flat-panel component of the rectangular through hole in described surface, described hole size is suitable for receiving the line of gold or scolder, thus this line calibration (indexing) is protruded in described surface, and described equipment is suitable for using shear load to it.

The line of gold or scolder can be very closely relevant with each ball deposit, and therefore provide the accurate calibration of a shear tool apparatus with respect to another.This equipment can comprise and be used for as required the line calibration being passed through described hole and being used for determining the device of each reticule in described lip-deep projection.The device that is used for calibration can motor driven.

According to second aspect, a kind of method of shearing tool of the ball deposit that is used to calibrate gold or scolder also is provided, the method comprising the steps of:

Flat surfaces with through hole rectangular with it is provided;

The line of gold or scolder is provided in described hole;

The described line of calibration is to give prominence on described surface; And

Utilize described cutter that the outshot of described line is carried out shearing test.

Line is consistent material, and is suitable for repeated test well, because the shearing force that detects can accurately repeat.Therefore, can will use the continuous shearing test of different shearing tools to be associated, and can contrast the shear sensors of consistent each cutter of standard calibration.

The mechanical property of line is normally known, and the shearing force of therefore utilizing this method to detect can relate to absolute and relative value.

Description of drawings

From below by the explanation with several preferred embodiments shown in the mode of example in the accompanying drawings, other features of the present invention will be conspicuous, in the accompanying drawings:

Fig. 1 schematically illustrates existing testing apparatus;

Fig. 2 schematically illustrates according to testing apparatus of the present invention with the ratio of amplifying;

Fig. 3 illustrates typical shearing test with side view;

Fig. 4 is the view on the online 4-4 of Fig. 3;

Fig. 5 is the alternative cutter with side view, and it has with the cutter elements shown in the longitudinal profile;

Fig. 6-8 illustrates a plurality of alternative cutters with side view;

Fig. 9 illustrates cutter with front elevation; And

Figure 10 is the horizontal section of the cutter of online ' 9 '-' 9 ' last Fig. 9.

Embodiment

With reference to the accompanying drawings, Fig. 1 illustrates existing proving installation, but it comprises stayed surface 11 and the measuring head 12 mobile with vertical (Z) with respect to its level (XY).This measuring head comprises anchor clamps, and cutter fabricated section 15 is attached to it by parallel arms 16.Test tool 17 is arranged on the cutter fabricated section 15.

In use, cutter is displaced sideways to the ball deposit that is installed on the surface 11 with the direction of arrow 14, carrying out shearing test, and the strainometer deterministic force of the deflection by response arm 16.The point of test tool 17 is very little usually, and has the magnitude of the diameter of ball deposit, that is, and and in the scope of 50-1000 μ m.

Fig. 2 shows the first embodiment of the present invention, and shows cutter 20, and it comprises support component 21, and its upper end 22 is suitable for being directly connected to the measuring head 12 of prior art or is connected to its anchor clamps in any suitable manner.Back one device guarantees to be used for the interchangeability of the parts of existing proving installation.

Lower end 23 comes to a point gradually, and has the piezoelectric crystal 24 that adheres to it.The outside surface of crystal has shielding 25.This crystal is illustrated as square, and other shape also is possible certainly, and is for example cylindrical.

This crystal has width common and the identical magnitude of ball deposit that will test, for example, and 100 μ m.The common electrical connection of not shown this crystal can detect the fluctuating stress of this crystal by it, and by calibration, calculates actual load.

This shielding can be the coverture of any suitable material, and it is suitable for protecting crystal to avoid mechanical damage, but still allows load to transmit fully to it.For example, described shielding can comprise the metal sheet that is attached to this crystal.

Fig. 3 shows in the use and will use the equipment of Fig. 2 of shear loads to being installed in ball deposit 27 on the substrate 28 in the direction of arrow 26.

It is the curved profile that how to be fit to ball deposit 27 that the sectional view of Fig. 4 illustrates this shielding and crystal.

Second embodiment shown in Fig. 5, and second embodiment comprises support component 21, and anvil 31 is suspended on the clip of pin 32 or any suitable type from it.This cutter is tabular, and can directly compressive load be applied to crystal 24.In a preferred embodiment, this cutter is by relative this crystal offsetting of its inner elastic force, for example, and by the thickness of the part that reduces to contact with upper end 22.

The anvil of replacing 33 shown in section, its depression 34 with part sphere is closely to mesh ball deposit.

Fig. 6 shows alternative embodiment, and wherein, the lower surface of cutter 40 has upwards anterior angle (rake) 49, makes at the height of guiding along 46 that can determine exactly before the shearing test on substrate 48.This anterior angle can be to guarantee to guide any suitable angle (typical, 15-30 ° scope) of keeping the mechanical integrity of cutter along the space, back simultaneously.

Fig. 7 is corresponding to Fig. 5, and shows similar negative rake 59.Fig. 8 shows the anvil 61 of replacement, and it is outstanding downwards, as shown in the figure, and the feasible negative rake that does not need this cutter remainder.

Fig. 8 and Fig. 9 show the exemplary arrangement of the assembly of typical cutter 70.

Cutter body 71, for example brassiness has a piezoelectric crystal mounted thereto 74.As directed, this crystal block section ground depression, and its sidewall is by silk 81 electrical isolations of for example nylon.

Cutter 71 is installed on the front surface of main body 71 by dormant screw; Countersunk guarantees the correct location of cutter, and avoids rotation by the bolt 82 in the groove 83 that is guided in main body 71.

The one side of crystal 74 (rear side) forms and the electrically contacting of main body 71, and the front has and is welded in itself and the lead-in wire 84 by the outstanding contact 85 of being connected internally to of main body.Suitable Embedding Material (potting material) 86 will contact stitch 85 and main body 71 insulation.

Piezoelectric crystal is commercial obtainable product, has roughly size and the 0.3mm thickness of 4mm * 2mm.The material typical case of crystal is toughness, hard non-conductive ceramic material, such as zirconia.

Anvil 71 has downward projection 87 and is used for contacting with test deposit.

In all embodiment, between crystal and main body and the interface between anvil and crystal can comprise for example load distribution layer of epoxy resin.This resin distribution is flowed simultaneously, and solidify so that smooth load paths really to be provided.Thereby avoid the slight imperfections in making or assembling, and therefore eliminate the Points And lines transfer (transfer) of load.When solidifying, epoxy resin has the advantage of holding member in the one assembling.

In use, utilize known technology, cutter is installed in measuring head, reduce, and withdraw from the distance of regulation to substrate.Drive cutter to the deposit that will test then, and shear-loaded is directly sent to piezoelectric crystal 74 from anvil 71, wherein strain deformation causes representing the electric signal of load, and it is sent to suitable record and analytical equipment, and this need not further specify at this.

A problem of the cutter of utilization such as element sensing power such as strainometer and piezoelectric crystal is to want calibration tool.Usually can not determine absolute value (as, in the breaking load of gram), and the user must rely on and allows result's relative value relatively.A kind of technology in back is an acceptable under the situation of only using a test tool, but can become problem when test tool need be replaced, and perhaps must compare the result of several similar cutters.

Figure 11 shows a kind of technology, whereby can comparing class like the load/output of shearing tool, and provide and the possibility of calibration tool, to provide the absolute reading of breaking load.

Substrate 91 has the hole 92 that extends through it with the right angle, and by its outstanding line 93.To shear this line in the test tool 94 that the direction of arrow 95 drives, and if suitably adjusting can measure relative breaking load.For example, this cutter can depend on electronics strainometer or the piezoelectric crystal equipment of describing in the presents.

Can come repeated test by the hole by line calibration with further length.The length that is appreciated that the line of top, hole can not be crucial, and impacts this line in each test test tool along identical axle; These features make that test is highly susceptible to realizing.

Line is very consistent material, and in addition, it is easy to as being applied to the scolder that is used in the substrate in the semiconductor equipment or the precursor of gold solder ball.Therefore, can use the precise materials that in the commercialization of test tool, to test to realize calibration testing.

Hole 92 should preferably fit closely to line 93, impacts with the right angle to guarantee test tool.

Understood, provided result with splendid repeatability according to the shearing test of this method.The similar effects of any not collinear projection can easily check by experience test, and if the line of consistent equivalent to present be necessary, also can comprise suitable dividing apparatus.

Therefore, this technology allows the similar cutter of calibration, and the cutter of nominal unanimity, makes the result who obtains from several different cutters to compare.Has special value under the situation of the calibration of the product test cutter of this technology in may being used in many different manufacturing occasions.

Also will understand, use knownly, and can obtain the much better indication of absolute breaking load, and make present technique allow the calibration testing cutter, to provide with for example reading value of gram, newton or any other appropriate units about the intensity of line and the information of material.

Claims

1. proving installation that is used for shear-loaded is applied to the ball deposit on the substrate, this device comprises: test tool (20), this test tool (20) is suitable for being connected to measuring head (12), this measuring head (12) can move with respect to described substrate, piezoelectric crystal (24) is installed to described test tool (20), described measuring head (12) moves to utilize described test tool (20) contact deposit, shear-loaded being applied to described deposit, thereby placing described piezoelectric crystal (24) under the stress and cause sending electric signal from it.

2. device as claimed in claim 1, wherein said test tool (20) is installed vertically and is had top and bottom, and wherein said piezoelectric crystal (24) is installed in the lower end of described test tool (20).

3. device as claimed in claim 1, wherein said test tool (20) have the bigger end supported by described measuring head (12) and with described bigger relative less end, end, and wherein said piezoelectric crystal (24) is installed in the less end of described test tool (20).