1、JEDEC STANDARD Coplanarity Test for Surface-Mount Semiconductor Devices JESD22-B108B (Revision of JESD22-B108A, January 2003) SEPTEMBER 2010 JEDEC SOLID STATE TECHNOLOGY ASSOCIATION NOTICE JEDEC standards and publications contain material that has been prepared, reviewed, and approved through the JE
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7、 Published by JEDEC Solid State Technology Association 2010 3103 North 10th Street Suite 240 South Arlington, VA 22201-2107 This document may be downloaded free of charge; however JEDEC retains the copyright on this material. By downloading this file the individual agrees not to charge for or resell
8、 the resulting material. PRICE: Contact JEDEC Printed in the U.S.A. All rights reserved PLEASE! DONT VIOLATE THE LAW! This document is copyrighted by JEDEC and may not be reproduced without permission. Organizations may obtain permission to reproduce a limited number of copies through entering into
9、a license agreement. For information, contact: JEDEC Solid State Technology Association 3103 North 10th Street Suite 240 South Arlington, VA 22201-2107 or call (703) 907-7559 JEDEC Standard No. 22-B108B Page 1 Test Method B108B (Revision of B108A) TEST METHOD B108B COPLANARITY TEST FOR SURFACE-MOUNT
10、 SEMICONDUCTOR DEVICES (From JEDEC Board Ballot JCB-02-122 and JCB-10-33, formulated under the cognizance of the JC-14.1 Subcommittee on Reliability Test Methods for Packaged Devices.) 1 Scope The purpose of this test is to measure the deviation of the terminals (leads or solder balls) from coplanar
11、ity at room temperature for surface-mount semiconductor devices. This test method is applicable for inspection and device characterization. If package warpage or coplanarity is to be characterized at reflow soldering temperatures, then JESD22-B112 should be used. 2 Apparatus The equipment utilized i
12、n this test shall be capable of measuring the deviation of the terminals from coplanarity to specified tolerances as determined by the applicable procurement document. Equipment must be capable of measurement accuracies within +/- 10% of the specified deviation. 3 Terms and definitions deviation fro
13、m coplanarity: The distance between the intended contact point of the terminal and the established seating plane or regression plane. regression plane: A plane that (1) passes through the apex of the terminal that has the greatest perpendicular distance from the package substrate, and (2) is paralle
14、l to the best-fit plane through the apexes of all terminals determined using the method of least squares. NOTE The regression plane may be used to emulate the package coplanarity during reflow soldering at the point of surface mounting. seating plane: The plane formed by the three terminal apexes th
15、at exhibit the greatest perpendicular distance from the package substrate, provided that the triangle formed by those three apexes encompasses the projection of the center of gravity (COG) of the component. terminal: An externally available point of connection. terminal apex: The point on the termin
16、al surface that exhibits the greatest perpendicular distance from the package substrate. JEDEC Standard No. 22-B108B Page 2 Test Method B108B (Revision of B108A) 4 Reference JEP95, Design Guide 4.17, BGA (Ball Grid Array) Package Measuring and Methodology. JESD22-B112, Package Warpage Measurement of
17、 Surface-Mount Integrated Circuits at Elevated Temperature. 5 Procedure There are two methods suitable for measurement of coplanarity. They are the seating plane method and the regression plane method. Each procedure produces a coplanarity value within the limits of error expected for this measureme
18、nt. Traditionally, the seating plane method of measuring deviation from coplanarity is preferred. However, the regression plane method is an acceptable alternative provided the results obtained correlate to those of the seating plane method. 5.1 Seating plane method The following procedures are to b
19、e used: a) Care must be taken in handling to ensure no damage to the terminals. b) The seating plane shall be in the horizontal position with the device placed as shown in Figure 1. It is preferable that the component terminals be measured while the component is in the dead-bug (leads-up) position.
20、c) When coplanarity measurements are made, there shall be no external forces applied to the device. d) Determine the apex of each and every terminal . e) Determine the three terminal apexes that exhibit the greatest perpendicular distance from the substrate. These form the seating plane, see Figure
21、1. Projectionof C.O.G.Figure 1 Three apexes forming the seating plane and encompassing projection of C.O.G JEDEC Standard No. 22-B108B Page 3 Test Method B108B (Revision of B108A) 5 Procedure (contd) 5.1 Seating plane method (contd) f) The triangle of terminals defining the seating plane must encomp
22、ass the projection of the center of gravity (C.O.G.) in order to constitute a valid seating plane. If the plane is not considered valid, the next terminal with the greatest perpendicular distance from the substrate shall be considered as a candidate terminal to be used in forming a valid seating pla
23、ne. If the seating plane triangle passes through the package center of gravity, the seating plane will be valid, but multiple seating planes could exist. If multiple seating planes do exist, the seating plane yielding the worst-case measurement shall be used for coplanarity determination. g) Deviati
24、on from coplanarity is measured as the distance from the seating plane to the apex of each and every terminal. The largest measurement is the deviation from coplanarity; see Figure 2 and Figure 3 (BGA versus leaded terminal). h) Report that the deviation from coplanarity was determined by the seatin
25、g plane method. Most equipment used for coplanarity measurement is programmed to automatically perform both seating and regression plane coplanarity measurements. Annex A is an illustrative example of how the seating plane on the terminals of a component is determined in the dead-bug position. Short
26、est ball from substrateSeating Plane Coplanarity valueFigure 2 Coplanarity measurement using seating plane method on ball grid array terminal Figure 3 Deviation from coplanarity measurement using seating plane method on leaded terminal SeatingPlaneCoplanarityDeviationJEDEC Standard No. 22-B108B Page
27、 4 Test Method B108B (Revision of B108A) 5 Procedure (contd) 5.2 Regression plane method The following procedures are to be used: a) Care must be taken in handling to ensure no damage to the terminals. b) The regression (least mean square) plane shall be in the horizontal position with the device pl
28、aced as shown in Figure 4. c) When coplanarity measurements are made, there shall be no external forces applied to the device. d) Determine the apex of each and every terminal. e) Determine the best-fit plane through the apexes of all terminals using the method of least squares. f) The regression pl
29、ane shall then be offset in a parallel manner to the apex of the terminal that exhibits the greatest perpendicular distance from the substrate. The distance from the offset regression plane to the terminal farthest away from the offset regression plane is the component deviation from coplanarity. g)
30、 Report that the deviation from coplanarity was determined by the regression plane method. Least Mean Square PlaneLowest Ball Reference Plane (parallel to LMS plane)Coplanarity DeviationFigure 4 Deviation from coplanarity measurement using regression plane method 6 Failure criteria Any device with o
31、ne or more terminals that exceeds the specified deviation from coplanarity shall constitute a failure. JEDEC Standard No. 22-B108B Page 5 Test Method B108B (Revision of B108A) 7 Summary The following details shall be specified in the applicable procurement document: a) The number of parts to be test
32、ed and the acceptance number. b) The maximum deviation from coplanarity. c) The preferred method by which coplanarity should be measured. JEDEC Standard No. 22-B108B Page 6 Test Method B108B (Revision of B108A) Annex A A.1 Determining seating plane Determining a seating plane is essentially a four-s
33、tep process. This process is usually programmed into the equipment used to measure coplanarity. A.1.1 Seating plane algorithm The first step is to determine the three points used for determining the seating plane. The algorithm used is typically like the illustration outlined in the next paragraphs.
34、 The principle is to determine if the origin lies within the interior of the triangle. The interior of the triangle is defined as the intersection of three regions: A.1.1.1 Each of the three regions is defined by an inequality ymx+b or ymx+b, where y=mx+b is the equation of the line joining two poin
35、ts (x1 and x2). (If the points determine a vertical line, m is undefined, see paragraph 4.) The direction of the inequality is determined for each pair by substituting the x coordinate of the remote point of the triangle into y=mx+b of the pair considered, and subtracting the resulting y from the y-
36、intercept, b. If the result is 0, the remote point lies below the line, and vice versa. So the region that includes the triangles interior is identified as lying above (in Excel: sign +1) or below (-1) the line. A.1.1.2 Next, we determine whether the origin is included in this region (lies on the sa
37、me side of the line as the remote point). This is done by comparing the sign obtained in step 1 to the sign of the y-intercept of the line. The y-intercept is positive if the origin lies below the line, and vice versa. When the two signs are multiplied, the result is -1 if the remote point and the o
38、rigin lie on the same side of the line. A.1.1.3 The origin lies within the triangle if (0,0) satisfies all three inequalities. This is true if and only if, for each of the three lines, the remote point lies on the same side of the line as the origin. The determination is made in Excel by adding the
39、three comparisons. A -3 result is positive; any other result is negative. A.1.1.4 Before executing step 1, each line is tested to see if it is vertical. (x2 - x1 = 0) If so, the comparison of remote point to origin is made in x instead of y, and simplifies to comparing the x of the remote point to t
40、he (constant) x of the line. (Excel displays error messages for m and b, but in the case of a vertical line, these values are not needed or used.) A.1.1.5 The above requires the origin to lie within, not on the margin of, the triangle formed by the three points considered. A.2 Method to determine se
41、ating plane A.2.1 A Cartesian coordinate system is placed with its origin at the geometric center of the component also called the component center of gravity. A.2.2 The X, Y, and Z of each apex is measured and tabulated. The apexes are sorted by Z, in descending order. JEDEC Standard No. 22-B108B P
42、age 7 Test Method B108B (Revision of B108A) Annex A (contd) A.2.3 The three highest (1, 2, and 3) are examined with the Seating Plane Algorithm to determine whether they form the seating plane. If they do not, apex trios are examined in order until a trio is found that determines the seating plane.
43、A.2.4 The order of trial is (1,2,3), (1,2,4), (1,2,5), . . . (1,2,n), (1,3,4), (1,3,5), . . .(1.3,n),. . .(1,n,n), (2,3,4), (2,3,5), . . . (n,n,n). Since the list is sorted by height, the first trio found that forms a triangle enclosing the origin will define the seating plane. A.3 Equation for seat
44、ing plane Next the measuring equipment uses the three points determined in A1 to determine the seating plane. This is done through an equation that is preprogrammed into measurement tool. A.4 Determining the distance to the seating plane Once the seating plane is determined, the measurement equipmen
45、t calculates the distance to the seating plane. The deviation from coplanarity is the largest distance from the seating plane to the apex of any terminal. A.5 Passing a reason test The deviation from coplanarity value determined in the steps above should be reviewed to verify that the value found is
46、 a reasonable one for the parts being measured. JEDEC Standard No. 22-B108B Page 8 Test Method B108B (Revision of B108A) Annex B (informative) Differences between JESD22-B108B and JESD22-B108A This annex briefly describes most of the changes made to entries that appear in this standard, JESD22-B108B
47、, compared to its predecessor, JESD22-B108A (January 2003). If the change to a concept involves any words added or deleted (excluding deletion of accidentally repeated words), it is included. Some punctuation changes are not included. Clause Description of change 1 Added “at room temperature” after
48、coplanarity in first sentence. 1 Added second and third sentences. 3 Put terms and definitions in alphabetical order, removed subclause numbers, and properly formatted (Per JM7). 3 “regression plane” reformatted editorially to be consistent with JESD88D. 4 Added reference to JESD22-B112A. Standard I
49、mprovement Form JEDEC JESD22-B108B The purpose of this form is to provide the Technical Committees of JEDEC with input from the industry regarding usage of the subject standard. Individuals or companies are invited to submit comments to JEDEC. All comments will be collected and dispersed to the appropriate committee(s). If you can provide input, please complete this form and return to: JEDEC Attn: Publications Department 3103 North 10thStreet Suite 240 South Arlington, VA 22201-2107 Fax: 703.907.7583 1. I recommend changes to the following: Requirement, clause number Test meth
