MIL- STD-883F 2004 TEST METHOD STANDARD MICROCIRCUITS - 第261页

MIL-STD-883F METHOD 2011.7 22 March 1989 1 METHOD 2011.7 BOND STRENGTH (DESTRUCTIVE BOND PULL TEST) 1. PURPOSE . The purpos e of thi s tes t is to measur e bond str engths, evaluate bond s trengt h dist ribut ions, or de…

MIL-STD-883F

METHOD 2010.11

18 June 2004

Condition A Condition B

Class level S Class level B

3.2.5.1 Foreign material, die coated devices

. This inspection and criteria shall be required on all devices that receive a

die coat during the assembly process. This inspection will be done after die coat cure. No device shall be acceptable that

exhibits:

a. Unattached foreign particles on the surface of the die coat or within the package that is (are) large enough to

bridge the narrowest spacing between unglassivated operating material (e.g., metallization, bare semiconductor

material, mounting material, bonding wire, etc.). Note: Semiconductor particles shall be considered as foreign

material.

b. Partially embedded foreign material with an "unembedded portion" that is large enough to bridge the narrowest

spacing between unglassivated operating material (e.g., metallization, bare semiconductor material, mounting

material, bonding wire, etc.).

c. Foreign material attached to or embedded in the die coat that appears to bridge unglassivated operating material

when viewed from above (e.g., bare semiconductor material, bond pads, bonding wire, mounting material, etc.).

d. Embedded foreign particles that penetrate the entire thickness of the die coating.

3.2.5.1.1 Die coating material

. No device shall be accepted that exhibits:

a. Surface scratches that penetrate the die coating and expose underlying glassivated metal.

b. Die coating that is lifted or is peeling from the semiconductor surface.

3.2.6 GaAs backside metallization

. GaAs inspection shall be performed with low magnification prior to die mounting.

(Verification at high magnification is permitted.) With the approval of the acquiring activity, the manufacturer may substitute

a sample inspection plan at the wafer level for 100 percent inspection in dice form. The sample inspection plan shall be

documented in the manufacturer's baseline documentation and shall be performed to the requirements of test method 5013.

No devices shall be acceptable that exhibit the following.

a. Evidence of metal corrosion, lifting, peeling, blistering.

b. Voids or scratches that expose underlying metal or substrate whose cumulative areas are more than 25 percent of

the cell area or device area.

NOTE: Absence of gold in the die separation area (saw street) of devices with electroplated backside metallization is

not a cause for rejection. Small voids at edges due to die separation are acceptable if they comprise less

than 10 percent of the backside area.

c. Any voids or scratches in the substrate via metallization that effects more than 25 percent of the metallization or

cause unintended isolation of the metallization path.

d. Underetched vias.

e. Overetched vias.

4. SUMMARY

. The following details shall be specified in the applicable acquisition document.

a. Test condition (see 3).

b. Where applicable, any conflicts with approved circuit design topology or construction.

c. Where applicable, gauges, drawings, and photographs that are to be used as standards for operator comparison

(see 2).

d. Where applicable, specific magnification (see 3).

MIL-STD-883F

METHOD 2011.7

22 March 1989

METHOD 2011.7

BOND STRENGTH (DESTRUCTIVE BOND PULL TEST)

1. PURPOSE

. The purpose of this test is to measure bond strengths, evaluate bond strength distributions, or determine

compliance with specified bond strength requirements of the applicable acquisition document. This test may be applied to

the wire-to-die bond, wire-to-substrate bond, or the wire-to-package lead bond inside the package of wire-connected

microelectronic devices bonded by soldering, thermocompression, ultrasonic, or related techniques. It may also be applied

to bonds external to the device such as those from device terminals-to-substrate or wiring board or to internal bonds

between die and substrate in non-wire-bonded device configurations such as beam lead or flip chip devices.

2. APPARATUS

. The apparatus for this test shall consist of suitable equipment for applying the specified stress to the

bond, lead wire or terminal as required in the specified test condition. A calibrated measurement and indication of the

applied stress in grams force (gf) shall be provided by equipment capable of measuring stresses up to twice the specified

minimum limit value, with an accuracy of ±5 percent or ±0.3 gf, whichever is the greater tolerance.

3. PROCEDURE

. The test shall be conducted using the test condition specified in the applicable acquisition document

consistent with the particular device construction. All bond pulls shall be counted and the specified sampling, acceptance,

and added sample provisions shall be observed, as applicable. Unless otherwise specified, for conditions A, C, and D, the

sample size number specified for the bond strength test shall determine the minimum sample size in terms of the minimum

number of bond pulls to be accomplished rather than the number of complete devices in the sample, except that the required

number of bond pulls shall be randomly selected from a minimum of 4 devices. Bond pulls in accordance with test

conditions D, F, G, and H, while involving two or more bonds shall count as a single pull for bond strength and sample size

number purposes. Unless otherwise specified, for conditions F, G, and H the sample size number specified shall determine

the number of die to be tested (not bonds). For hybrid or multichip devices (all conditions), a minimum of 4 die or use all die

if four are not available on a minimum of 2 completed devices shall be used. Where there is any adhesive, encapsulant or

other material under, on or surrounding the die such as to increase the apparent bond strength, the bond strength test shall

be performed prior to application.

When flip chip or beam-lead chips are bonded to substrates other than those in completed devices, the following conditions

shall apply:

a. The sample of chips for this test shall be taken at random from the same chip population as that used in the

completed devices that they are intended to represent.

b. The chips for this test shall be bonded on the same bonding apparatus as the completed devices, during the time

period within which the completed devices are bonded.

c. The test chip substrates shall be processed, metallized, and handled identically with the completed device

substrates, during the same time period within which the completed device substrates are processed.

3.1 Test conditions

3.1.1 Test condition A - Bond peel

. This test is normally employed for bonds external to the device package. The lead or

terminal and the device package shall be gripped or clamped in such a manner that a peeling stress is exerted with the

specified angle between the lead or terminal and the board or substrate. Unless otherwise specified, an angle of 90 degrees

shall be used. When a failure occurs, the force causing the failure and the failure category shall be recorded.

3.1.2 Test condition C - Wire pull (single bond)

. This test is normally employed for internal bonds at the die or substrate

and the lead frame of microelectronic devices. The wire connecting the die or substrate shall be cut so as to provide two

ends accessible for pull test. In the case of short wire runs, it may be necessary to cut the wire close to one termination in

order to allow pull test at the opposite termination. The wire shall be gripped in a suitable device and simple pulling action

applied to the wire or to the device (with the wire clamped) in such a manner that the force is applied approximately normal

to the surface of the die or substrate. When a failure occurs, the force causing the failure and the failure category shall be

recorded.

MIL-STD-883F

METHOD 2011.7

22 March 1989

3.1.3 Test condition D - Wire pull (double bond). This procedure is identical to that of test condition C, except that the

pull is applied by inserting a hook under the lead wire (attached to die, substrate or header or both ends) with the device

clamped and the pulling force applied approximately in the center of the wire in a direction approximately normal to the

die or substrate surface or approximately normal to a straight line between the bonds. When a failure occurs, the force

causing the failure and the failure category shall be recorded. The minimum bond strength shall be taken from table I.

Figure 2011-1 may be used for wire diameters not specified in table I. For wire diameter or equivalent cross section

>0.005 inch, where a hook will not fit under the wire, a suitable clamp can be used in lieu of a hook.

3.1.4 Test condition F - Bond shear (flip chip)

. This test is normally employed for internal bonds between a

semiconductor die and a substrate to which it is attached in a face-bonded configuration. It may also be used to test the

bonds between a substrate and an intermediate carrier or secondary substrate to which the die is mounted. A suitable

tool or wedge shall be brought in contact with the die (or carrier) at a point just above the primary substrate and a force

applied perpendicular to one edge of the die (or carrier) and parallel to the primary substrate, to cause bond failure by

shear. When a failure occurs, the force at the time of failure, and the failure category shall be recorded.

3.1.5 Test condition G - Push-off test (beam lead)

. This test is normally employed for process control and is used on

a sample of semiconductor die bonded to a specially prepared substrate. Therefore, it cannot be used for random

sampling of production or inspection lots. A metallized substrate containing a hole shall be employed. The hole

appropriately centered, shall be sufficiently large to provide clearance for a push tool, but not large enough to interfere

with the bonding areas. The push tool shall be sufficiently large to minimize device cracking during testing, but not large

enough to contact the beam leads in the anchor bond area. Proceed with push-off tests as follows: The substrate shall

be rigidly held and the push tool inserted through the hole. The contact of the push tool to the silicon device shall be

made without appreciable impact (less than 0.01 inch/minute (0.254 mm/minute ) and forced against the underside of

the bonded device at a constant rate. When failure occurs, the force at the time of failure, and the failure category shall

be recorded.

3.1.6 Test condition H - Pull-off test (beam lead)

. This test is normally employed on a sample basis on beam lead

devices which have been bonded down on a ceramic or other suitable substrate. The calibrated pull-off apparatus (see

2) shall include a pull-off rod (for instance, a current loop of nichrome or Kovar wire) to make connection with a hard

setting adhesive material (for instance, heat sensitive polyvinyl acetate resin glue) on the back (top side) of the beam

lead die. The substrate shall be rigidly installed in the pull-off fixture and the pull-off rod shall make firm mechanical

connection to the adhesive material. The device shall be pulled within 5 degrees of the normal to at least the calculated

force (see 3.2), or until the die is at 2.54 mm (0.10 inch) above the substrate. When a failure occurs, the force at the

time of failure, the calculated force limit, and the failure category shall be recorded.

3.2 Failure criteria

. Any bond pull which results in separation under an applied stress less than that indicated in

table I as the required minimum bond strength for the indicated test condition, composition, and construction shall

constitute a failure.

3.2.1 Failure category

. Failure categories are as follows: When specified, the stress required to achieve separation

and the category of separation or failure shall be recorded.

a. For internal wire bonds:

(a-1) Wire break at neckdown point (reduction of cross section due to bonding process).

(a-2) Wire break at point other than neckdown.

(a-3) Failure in bond (interface between wire and metallization) at die.

(a-4) Failure in bond (interface between wire and metallization) at substrate, package post, or other than die.

(a-5) Lifted metallization from die.

(a-6) Lifted metallization from substrate or package post.

(a-7) Fracture of die.

(a-8) Fracture of substrate.