JP2015148481A - Flatness measuring device of bga and flatness measurement method of bga - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flatness measuring device of BGA for measuring deformation of a package during heating without mechanical removal of a solder ball.SOLUTION: Measurement data 60a-1 and measurement data 60b-1 are piled together, to thereby generate ball existence surface three-dimensional shape data 16-1. Solder ball data parts 58-1 and 58-2 are determined by a ball absence surface three-dimensional shape data generation part, and the solder ball data parts 58-1 and 58-2 are removed by program processing, to thereby generate ball absence surface three-dimensional shape data 21-1.

Description

  The present invention relates to a BGA flatness measuring apparatus and a BGA flatness measuring method for measuring a change in flatness of a package part when a BGA (Ball Grid Array) having a large number of solder balls on a package plane is heated.

  As a conventional technique, Patent Document 1 discloses a method for measuring the flatness of a BGA including a large number of solder balls arranged on the surface of a package.

JP 2012-78248 JP

  The technique of Patent Document 1 described above creates a ball removal package in which all the BGA solder balls are mechanically deleted, and uses a contour line observation measurement method (moire method) with interference fringes (images) at room temperature of the ball removal package. This is a measurement method in which the degree of warping at normal temperature is measured, the degree of warping at peak temperature at the heating peak temperature is measured, and the degree of warping at the heating peak temperature from normal temperature is measured.

The measurement method disclosed in Patent Document 1 is troublesome in that it takes time to mechanically delete the solder ball, deformation of the package due to the deletion operation, change in thickness due to excessive cutting, and scratches.
Further, since the measurement is a heating measurement of a package in which solder balls are mechanically deleted (hereinafter referred to as “ball deletion package”), the deformation is different from the deformation of a package with solder balls (hereinafter also referred to as “package with balls”). Therefore, it cannot be said that the deformation of an actual package with a ball is accurately measured.
In general, in order to photograph the irradiation pattern of interference fringes, it has been necessary to apply a special paint such as a white paint to the ball removal package.
In addition, “correlation between terminal surface and stamped surface” and “reflow heat history equivalent to ball mounting” were necessary.

However, when measuring BGA, the JEITA (EIAJ) standard (Japan Electronics and Information Technology Industries Association) is standardized as follows.
<Quoted from JEITA ED-7306>
* Measurement location
JESD22B112: Measures the terminal area on the bottom of the board without a ball.
JEITA regulation outline: The measurement location is not the ball apex, but the substrate surface. Based on the measurement of the terminal surface, measurement from the opposite surface (usually the stamped surface) is allowed only when the correlation is proven.
* Ball removal
JESD22B112:
・ If there is no ball in advance, a reflow heat history equivalent to mounting the ball is required.
-When measuring with the ball removed, check the effect of removal in advance.
JEITA regulation outline:
・ If there is no ball in advance, a reflow heat history equivalent to mounting the ball is required.
・ When removing the ball and measuring, it is recommended to remove it without mechanical heating.

  In view of the drawbacks of the prior art as described above, the present invention does not require the correlation between the terminal surface and the marking surface, the reflow heat history equivalent to mounting of solder balls, and without removing the solder balls mechanically. An object of the present invention is to provide a BGA flatness measuring device and a BGA flatness measuring method for measuring deformation of a package.

In order to achieve the above object, the present invention is configured as follows.
<Invention of Claim 1>
A heating unit having a heating means and a work setting unit, and heating the BGA having a large number of solder balls on a package plane, which is set in the work setting unit, by the heating means;
An irradiating unit for irradiating measurement light toward a surface having a solder ball having the solder ball of the package;
Three-dimensional shape data with a ball for measuring the reflected light of the measurement light irradiated on the surface with the solder ball and generating three-dimensional shape data with a ball, which is the surface three-dimensional shape data of the surface with the solder ball The creation department;
A ball-free surface three-dimensional shape data creating unit that creates a ball-free surface three-dimensional shape data by excluding the solder ball data portion by program processing from the three-dimensional shape data with the ball;
A flatness measuring apparatus for BGA, comprising:

  “BGA” is a Ball Grid Array, which is a kind of IC chip surface-mount type packaging method in which small ball-shaped electrodes are arranged from a planar package.

“3D” is used synonymously with “3D”.
“Measurement light” includes the following measurement light and measurement method.
“Optical cutting method” in which a line-shaped laser light source is irradiated onto an inspection work and the reflected light is acquired as height data (profile). There is a method in which the distance from the workpiece is measured (measured) based on triangulation, and the entire workpiece is measured by moving the workpiece or the light source at the time of inspection to obtain a three-dimensional shape.
There is also a pattern projection method in which a stripe pattern (striped pattern) is projected, a workpiece is measured on a surface, and a three-dimensional shape is acquired.
The “measurement light” and the measurement method are not limited to the above.

<Invention of Claim 2>
2. The BGA flatness measuring apparatus according to claim 1, wherein the measuring light is striped light.

<Invention of Claim 3>
The measurement light is row light and column light,
Row data is obtained by the row light,
Column data is obtained by the column light,
The three-dimensional shape data with the ball is formed by the row data and the column data,
In order to exclude the solder ball data portion from the three-dimensional shape data with the ball,
(1) A row approximation correction is performed in which a row approximation line and a row cut level are drawn with respect to the data for each row of the row data, and a row correction data is generated by excluding a data portion exceeding the row cut level. Done
(2) In the data part excluded by the row correction, the data of the final confirmed row approximate line that has been finalized is put into one row of data,
(3) The processing of (1) and (2) is performed on all row data to create all row approximate correction data,
(4) A column approximation correction is performed in which a column approximation line and a column cut level are drawn with respect to the data of each column of the column data, and a column correction data is generated by excluding a data portion exceeding the column cut level. Done
(5) In the data part excluded by the column correction, the data of the final confirmed column approximate line is finalized to create one column of data,
(6) All the column data are subjected to the processes (4) and (5) to create all column approximation correction data,
(7) The ball-free surface three-dimensional shape data is created from the all-row approximate correction data and the all-column approximate correction data, according to any one of claims 1 and 2. It is a flatness measuring device of BGA.

<Invention of Claim 4>
The row approximation correction and the column for creating a low mountain solder ball data portion in which a part of the solder ball data portion is cut and the solder ball portion is lowered and excluding the low mountain solder ball data portion. 4. A flatness measuring apparatus for a BGA according to claim 3, wherein the processing after the approximate correction is performed.

<Invention of Claim 5>
A measurement unit having a heating unit setting unit for setting the heating unit is provided,
The irradiation unit is provided in the measurement unit;
The measurement unit and the heating unit are separated.
5. The BGA flatness measuring apparatus according to claim 1, wherein the heating unit is set to the heating unit setting section in a removable form. 6. is there.

<Invention of Claim 6>
A heating step for heating the BGA;
A measurement light irradiation step of irradiating the measurement light toward the surface having the solder balls having the BGA solder balls being heated in the heating step;
Three-dimensional shape data with a ball for measuring the reflected light of the measurement light irradiated on the surface with the solder ball and generating three-dimensional shape data with a ball, which is the surface three-dimensional shape data of the surface with the solder ball Creation process,
The ball-free surface 3D shape data, which is the surface 3D shape data of the package without the solder ball data portion, is created by excluding the solder ball data portion by program processing from the ball-side surface 3D shape data Surface 3D shape data creation process;
It is a BGA flatness measuring method characterized by comprising the above steps.

As is clear from the above description, the present invention has the following effects.
<Effect of the Invention of Claim 1>
3D surface data of a package without the solder ball data portion by excluding the solder ball data portion by program processing from the three-dimensional shape data with the ball surface obtained by measuring while heating the BGA with the solder ball. Since it creates 3D shape data without balls, which is shape data, there is no need to mechanically scrape the solder balls from the package. Reflow heat history equivalent to ball mounting is obtained and the effect of ball removal is confirmed in advance. There is no need for the above, and it is possible to measure the exact deformation of the package in the presence of the solder balls.

<Effects of Invention of Claim 2>
The effect similar to that of the first aspect of the invention is achieved, and the measurement light is a striped pattern light that projects a striped pattern. Therefore, since the entire surface with the ball is measured instantaneously, the surface measurement is performed in one second, for example. There is an effect that the measurement can be performed at a speed of one to several times or more.
Therefore, for example, it is possible to measure and display a change in the workpiece once or more per second. That is, real-time workpiece (BGA) changes can be acquired and output.

<Effect of the Invention of Claim 3>
In addition to the same effects as the invention described in any one of claims 1 and 2, there is an effect that noise can be excluded by approximation correction and measurement data can be made highly accurate with little noise.

<Advantageous Effects of Invention>
According to the third aspect of the present invention, the same effect as that of the invention described in claim 3 can be obtained, and by applying an approximate correction to the low mountain solder ball data portion in which a part of the solder ball data portion is cut, the solder ball data portion is pulled and the warp or valley warp Therefore, the measurement data can be made highly accurate with less noise.
Even if the data amount of the solder ball portion is larger than the data amount of the package portion and an approximate line is drawn to the solder ball portion, the data amount of the solder ball portion is lower than the data amount of the package portion. By using the mountain solder ball data portion, it is possible to prevent an approximate line from being drawn in the solder ball portion, and therefore, there is an effect that high-precision measurement data can be obtained.

<Effect of the Invention of Claim 5>
While having the same effect as that of the invention according to any one of claims 1 to 4, the heating unit and the measurement unit having the irradiation unit are each independently configured to be removable, so the heating unit is removed, There exists an effect that it can be used also as a shape measuring apparatus of workpieces other than BGA.

<Advantageous Effects of Invention>
The same effect as that of the first aspect of the invention can be obtained.

1 is an overall configuration diagram of Embodiment 1 of the present invention. The block diagram of the measurement head and heating unit of Example 1 of this invention. 1 is a block diagram of Embodiment 1 of the present invention. 1 is an external perspective view of a heating unit according to a first embodiment of the present invention. The flowchart of Example 1 of this invention. FIG. 3 is a partially enlarged perspective view illustrating a projection state of measurement light onto a BGA according to the first embodiment of the present invention. FIG. 3 is an image of an exclusion process of a solder ball data portion according to the first embodiment of the present invention. The figure which shows the 1st approximation correction of Example 1 of this invention. The figure which shows the 2nd approximation correction of Example 1 of this invention. The figure which shows the 3rd approximation correction of Example 1 of this invention. The figure which shows the last correction | amendment of Example 1 of this invention. The figure which shows the partial cut method of the solder ball data part of Example 1 of this invention. The figure which shows the partial cut method of the solder ball data part of Example 1 of this invention.

  Embodiments that are the best mode for carrying out the present invention will be described below. However, the present invention is not intended to be limited to these examples. Further, in the description of the embodiments to be described later, the same reference numerals are given to the same components of the above-described embodiments, and the overlapping description is omitted.

In the first embodiment of the present invention shown in FIGS. 1 to 13, the BGA flatness measuring apparatus 1 has the following configuration. (See Figure 1)
The casing includes a U-shaped measurement unit 2, a heating unit 3, and a control unit 4.
The measuring unit 2 is provided with a heating unit setting section 5 for setting the heating unit 3 in a detachable form. The heating unit set portion 5 is provided with a protrusion fitting hole 7 (which may be a protrusion) so that the protrusion 6 (which may be a dent) provided on the bottom of the heating unit 3 is fitted and does not move.

The measurement unit 2 includes a measurement head 14 and a measurement controller 18. (See Figure 1)
The measurement head 14 (see FIG. 2) includes row light 8a-1 to 8a-n which is horizontal stripe pattern measurement light, and column light 8b-1 to 8b-n which is vertical stripe pattern measurement light (stripe pattern). = Row light 8a-1 to 8a-n irradiated to the surface 12 with solder balls having the solder balls 11 of the package 10 of the BGA 9 which is a work, A light receiving unit 31 having a three-dimensional measuring unit 13 that performs three-dimensional measurement of the surface 12 with the solder balls from the reflected light 30 of the light 8b-1 to 8b-n is incorporated.
The measurement controller 18 (see FIG. 3) creates a ball-side surface 3D shape data 16 which is a surface three-dimensional shape data of the surface 12 with a solder ball from the measurement data 15 of the three-dimensional measurement unit 13. A dimensional shape data creation unit 17 is provided.
The light sources 32a and 32b of the row light 8a-1 to 8a-n and the column light 8b-1 to 8b-n are composed of two LEDs of different light colors. (See Figure 2)

The row light 8a-1 to 8a-n means that the row light 8a-1 and the row light 8a-2 have different types of measurement light. For example, the thickness of the irradiation light of the row light 8a-1 is different from the thickness of the irradiation light of the row light 8a-2. Therefore, it means that there are n types of irradiation rays. The same applies to the measurement light column light 8b-1 to 8b-n.
Further, the measurement light irradiation measurement is performed by measuring a plurality of times while shifting by a predetermined phase for each row.

Stripe pattern measurement light is alternately emitted from the irradiation units 8 a and 8 b (see FIG. 3), and each is measured by the three-dimensional measurement unit 13. The row light 8a-1 and the column light 8b-1 are the same striped pattern measurement light having different directions.
First three-dimensional shape data with a ball is created from the measurement data of the row light 8a-1 + the vertical light 8b-1, and the second three-dimensional shape data with a ball is created by the row light 8a-2 + the vertical light 8b-2. The third ball-equipped surface three-dimensional shape data is created by the row light 8a-3 + column light 8b-3, and the n-th ball-equipped surface three-dimensional shape data is created by the row light 8a-n + column light 8b-n. The three-dimensional shape data 16 with a ball is created, in which the measurement time and the estimated workpiece temperature are added to the first to n-th three-dimensional shape data with a ball.
Only one of the first three-dimensional shape data with a ball to the n-th three-dimensional shape data with a ball may be used as the three-dimensional shape data 16 with a ball.

In the prototype device of the first embodiment, the measurement head 14 and the measurement controller 18 use the Keyence Corporation image processing system XG-8000 series (the measurement head is XR-Series, XR-HT40M or XR-HT15M). Yes.
The imaging device is a monochrome CMOS imaging device, the shutter speed is 50 μs to 200 ms, and the data interval (X, Y) is 9.5 μm (XR-HT15M), 18.5 μm (XR-HT40M).
These measuring heads measure in real time a collective three-dimensional measurement (= collective three-dimensional inspection) including the presence / absence of a BGA solder ball, a ball pitch measurement, and a height measurement.
The array designation region can designate and measure up to 10,000 measurement points (inspection points) at a time, and can perform multipoint simultaneous measurement of the height area.

XR-HT40MD or XR-HT15MD that can be directly connected to a PC (corresponding to the control unit 4) without using the measurement controller 18 may be used as the measurement head 14.
In this case, the ball-equipped surface three-dimensional shape data creation unit 17 is provided on the measurement head 14 side or the control unit 4 side.

The control unit 4 (see FIG. 3) excludes the solder ball data portion 20 from the three-dimensional shape data 16 with the ball by program processing, and uses the surface three-dimensional shape data of the package 10 without the solder ball data portion 20. A ball-less surface three-dimensional shape data creating unit 22 for creating a certain ball-free surface three-dimensional shape data 21 is provided.
The control unit 4 includes a heating unit control unit 23 that controls the temperature in the heating unit 3, a heating chamber control data storage unit 25 that stores heating procedure data acquired in advance, and a measurement head 14. A setting instruction unit 26 is provided for setting, heating unit 3, and various data output settings.
Various data such as the three-dimensional shape data 16 with a ball, the three-dimensional shape data 21 without a ball, and temperature data are integrated into the output unit 27 and output based on an instruction from the setting unit 28.
Various setting instructions are given through the screen of the monitor 24.

  The heating unit 3 (see FIGS. 2, 3, and 4) includes a housing 36 having a recessed portion 35 at the center upper portion, hot air supply units 37 a and 37 b provided on the left and right sides of the housing 36, and hot air Exhaust parts 38a, 38b, a heating chamber 39 to which hot air 47a, 47b from hot air supply parts 37a, 37b is supplied, and a ceramic work set on which BGA 9 is placed and set at the center of the heating chamber 39 Part 40.

The heating chamber 39 (see FIGS. 2 and 4) is provided with a work set unit 40 in the center of a ceramic base 41.
On the left side of the base 41, a hot air supply part 37a having a heating means 42a composed of a heater, and a hot air exhaust part 38a are arranged below the hot air supply part 37a.
On the right side of the base 41, a hot air supply part 37b having a heating means 42b made of a heater and a hot air exhaust part 38b are arranged below the hot air supply part 37b.
Either or both of the heating means 42a and 42b and the blower (not shown) are controlled by the heating unit controller 23 so that the temperature of the heating chamber 39 becomes a predetermined temperature.

The ceiling wall of the heating chamber 39 is a double-layer heat-resistant transparent glass 43, and the front and rear walls are also double-layer heat-resistant transparent glass walls.
The two-layer heat-resistant transparent glass 43 is incorporated in a ceramic ceiling plate 44 that closes the heating chamber 39 from above.
Screws 45a and 45b with knobs that can be freely rotated with fingers are provided on the left and right sides of the ceiling plate 44. The screws 45a and 45b with knobs are screwed into female screws 46a and 46b provided in the housing 36 and tightened to fix the ceiling plate 44 having the two-layer heat-resistant transparent glass 43 and seal the ceiling of the heating chamber 39. .
When the screws 45a and 45b with knobs are loosened and the screwing with the female screws 46a and 46b is released, the ceiling plate 44 can be removed from the ceiling of the heating chamber 39, and in this removed state, the BGA 9 is placed on the work set unit 40. And do the removal.

The heating chamber 39 is provided with a temperature sensor 48 that detects the temperature in the heating chamber 39.
The temperature sensor 48 and the heating means 42 a and 42 b are connected to the heating unit controller 23.
The heating unit controller 23 controls the heating means 42a and 42b based on the heating chamber control data 49 so that the temperature of the heating chamber 39 becomes a predetermined temperature.

The heating chamber control data 49 is acquired as follows.
The actual furnace heating data obtained by measuring the temperature change of the BGA 9 in advance in the actual reflow furnace by attaching the workpiece temperature detection sensor directly to the BGA 9 is stored in the actual furnace heating data storage unit 52.
The BGA 9 directly attached with the workpiece temperature detection sensor is set in the workpiece setting unit 40.
Hot air 47a, 47b is supplied to the heating chamber 39 from the hot air supply units 37a, 37b.
The heating means 42a and 42b are controlled so that the temperature change of the BGA 9 on the work set unit 40 becomes the same change as the actual furnace heating data, and the room temperature control data measured by the temperature sensor 48 at that time is the heating chamber control data. 49 is stored in the heating chamber control data storage unit 25.
That is, data relating the temperature of the heating chamber measured by the temperature sensor 48 and the workpiece temperature of the BGA 9 measured by the workpiece temperature detection sensor is the heating chamber control data 49, and the workpiece temperature A at the heating chamber temperature A ° C. '° C is given to the three-dimensional shape data 16 with the ball as the estimated workpiece temperature together with the measurement time.

The subsequent heating measurement (main measurement) of the BGA 9 without the direct workpiece temperature detection sensor is temperature management of the heating chamber 39 based on the heating chamber control data 49 and the measured temperature data of the temperature sensor 48.
In the heating measurement (main measurement) of the BGA 9, for example, when the temperature of the heating chamber measured by the temperature sensor 48 is 200 ° C., the temperature of the BGA 9 is 190 ° C. (estimated workpiece temperature) based on the heating chamber control data 49. Heating control is performed by estimation.

  Which of the row light 8a-1 to 8a-n and the column light 8b-1 to 8b-n irradiated from the measuring head 14 is used, how many types are used, and how many times the number of times of irradiation and measurement are performed per second. Whether or not to set can be set by the setting unit 28.

FIG. 6 shows a part (upper diagram) of the surface 12 with solder balls of the BGA 9, a state (in the middle diagram) where the surface 12 with solder balls is irradiated with the row light 8 a-1 that is a row stripe pattern, and a column stripe pattern. The state (lower figure) in which a certain column light 8b-1 is irradiated is shown. The solder balls are a solder ball 11-1 and a solder ball 11-2.
As described above, the row light 8a-1 to 8a-n and the column light 8b-1 to 8b-n are alternately irradiated and do not overlap.

FIG. 7 is an image of measurement data obtained by measuring the irradiated measurement light in FIG. 6 and subsequent data processing.
In the three-dimensional measuring unit 13, the row data 60a-1 (FIG. 7A), which is measurement data of the irradiated row light 8a-1, and the column, which is measurement data of the irradiated column light 8b-1. Data 60b-1 (FIG. 7B) is created.
In the measurement controller 18, the row data 60a-1 and the column data 60b-1 are overlapped to create the three-dimensional shape data 16-1 with a ball ((FIG. 7C)).
In the ball-free surface three-dimensional shape data creation unit 22, the solder ball data portions 58-1 and 58-2 are judged, and the solder ball data portions 58-1 and 58-2 are excluded (erased) by a program process. The non-surface three-dimensional shape data 21-1 (FIG. 7D) is created.

The row solder ball data portion of the row data 60a-1 is specified and the row solder ball data portion is excluded, and 3D shape data without row balls is created,
Creating three-dimensional shape data without column balls by identifying the column solder ball data portion of the column data 60b-1 and excluding the column solder ball data portion;
The three-dimensional shape data 21-1 without balls may be generated from the three-dimensional shape data without row balls and the three-dimensional shape data without columns balls.

The measurement of the heat deformation of the BGA 9 is as follows.
Simultaneously with heating of the heating chamber 39 or immediately before the heating, irradiation with the row light 8a-1 to 8a-n and the column light 8b-1 to 8b-n is performed, three-dimensional measurement is performed, and a ball every predetermined time (measurement time) The three-dimensional shape data 16 having the three-dimensional shape with the ball is created by the three-dimensional shape data creating unit 17 with the ball and the measurement time 59 and the estimated work temperature 57 are given. The data is stored in the storage unit 55.
The heating chamber temperature 56 of the heating chamber 39 at every measurement time 59 is detected by the temperature sensor 48, the estimated workpiece temperature 57 at the heating chamber temperature 56 is specified, and the ball-equipped surface is stored in the three-dimensional shape data storage unit 55 having the ball. It is associated with the three-dimensional shape data 16 and stored (given and stored).
The ball-side surface three-dimensional shape data 16 is determined by the ball-free surface three-dimensional shape data creating unit 22 to determine the solder ball data portions 58-1 to 58-n, and the solder ball data portions 58-1 to 58n are determined by program processing. The excluded ball-free surface three-dimensional shape data 21 is created, and the ball-free surface three-dimensional shape data 21 is stored in the ball-free surface three-dimensional shape data storage unit 54.

  The three-dimensional shape data 21 and its detailed data are, for example, every 0.1 seconds, every 0.2 seconds, every 0.3 seconds, every 0.4 seconds, every 0.5 seconds, and 0.6 seconds. Every 0.7 seconds, every 0.8 seconds, every 0.9 seconds, or every second is measured and stored, and the change can be visually and numerically viewed on the monitor 24. It is like that.

Next, a correction method in which the solder ball data portions 58-1 to 58-n are excluded by program processing will be described with reference to FIGS.
(1) The first row approximate line and the first row cut level are subtracted from the first row raw data for one row of the row data 60a-1 with noise, and the first row cut level is exceeded. Excluding (erasing) the data portion and performing the first row approximation correction for creating the first row correction data (corrected raw data 1) (FIG. 8),
(2) By subtracting the second row approximation line and the second row cut level from the first row correction data (corrected raw data 1), the data portion exceeding the second row cut level is excluded and 2 The second row approximation correction for creating the second row correction data (corrected raw data 2) is performed (FIG. 9),
(3) The third row approximate line and the third row cut level are subtracted from the second row correction data (corrected raw data 2), and the data portion exceeding the third row cut level is excluded and 3 The third row approximation correction for creating the third row correction data (corrected raw data 3) is performed (FIG. 10),
(4) The final confirmed row approximate line data is put in the data portion excluded in the first row correction to the third row correction (the number of data of 4, 6, 8, 10, 12, 14). Value (10)), and create one horizontal row of data (FIG. 11)
(5) The processing of (1) to (4) is performed on all rows to create all row approximate correction data,
(6) Create a first column approximation line and a first column cut level for each column of the column data 60b-1, and exclude data portions that exceed the first column cut level. Perform the first column approximation correction to create the first column correction data,
(7) A second column approximation line and a second column cut level are created for the first column correction data, and a data portion exceeding the second column cut level is excluded and the second column correction data is excluded. Perform the second column approximation correction to create
(8) A third column approximation line and a third column cut level are created for the second column correction data, and a data portion exceeding the third column cut level is excluded, and the third column correction data is excluded. Perform the third column approximation correction to create
(9) Put the data of the final confirmed column approximate line finally finalized in the data part excluded in the first column correction to the third column correction, and create one column of data,
(10) The processing of (6) to (9) is performed on all columns to generate all column approximation correction data,
(11) The ball-free surface three-dimensional shape data 21-1 is created from the all-row approximate correction data and the all-column approximate correction data.
As described above, noise is cut and processing for determining the tendency of the three-dimensional shape data without a ball is performed.
The number of approximation correction processes is arbitrary, and may be one or may be multiple.

A correction sequence A for correcting the three-dimensional shape data with a ball and excluding (cutting) only the solder ball data portion will be described.
1: Reading 3D shape data with ball surface 2: Square plane correction 3: Approximate correction cut level 0.05mm
4: Average processing (average of 9 adjacent)
By applying approximate correction in the XY direction, the influence of the solder ball data part can be suppressed and the overall warping tendency can be seen. The line may be attracted by the inclination of each line, but it is avoided by performing the averaging process.

A correction sequence B for correcting the three-dimensional shape data with the ball and excluding the solder ball data portion will be described.
1: Reading 3D shape data with ball surface 2: Square plane correction 3: Level cut (cut at 50% of 0.1 to -0.14)
4: Average processing 5: Approximate correction cut level 0.05mm
6: Average processing (average of 9 adjacent)

When the polarity of the approximate line changes due to being pulled by the solder ball data part (the data part without the ball is concavely warped, the ball part is convexly warped, etc.), a part of the solder ball data part is cut and approximate correction is performed. To.
Specifically, using a level cut, a part of the solder ball data part is cut and the low mountain solder ball data part is drawn, and an approximate correction is applied to this low mountain solder ball data part, so that the solder ball data part Eliminate the tendency to be warped by being pulled by. Therefore, correction is performed on the low mountain solder ball data portion with the solder ball data portion cut out as much as possible.
1: Enter the solder ball diameter.
2: An edge having a 50% height (diameter) of the solder ball data portion is detected (FIG. 12A). (Rising edge-falling edge)
For example, 50% of 0.1 to -0.14 is cut, and data of 0.12 or more is cut. Since the solder ball data part diameter is about 0.2 mm, about half is cut.
3: Vertices are detected from within the edge (FIG. 12B).
4: The diameter + 10% of the solder ball data portion is detected from the apex (FIG. 12C).
5: Linear interpolation is performed between the diameter and 10% (FIG. 12D).
6: Approximate correction is applied.
7: Multiply the surface average.

Data decimation is required.
Or it is necessary to perform a binning process with a three-dimensional sensor.
Number of data without binning: 2048 x 2048
Number of data with binning: 1024 x 1024
The binning process is a function of amplifying and detecting a signal by virtually enlarging a light receiving area by grouping several adjacent elements (pixels) on a CCD chip. Since the sensitivity is basically proportional to the area of the CCD, the binning sensitivity is 4 times for binning 2 (2 × 2) and 16 times for binning 4 (4 × 4). In addition, when binning is applied, the resolution decreases depending on the degree of the binning, but there is an advantage that the file capacity becomes small and it is easy to handle.

In the above, the diameter + 10% of the solder ball data portion is detected from the apex, and linear interpolation is performed between the diameter + 10%.
Depending on the situation, it is also effective to increase the interval between the solder ball data portions by detecting the diameter -10% of the solder ball data portions from the apex and linearly interpolating between the diameters -10%.

The technical idea is to detect plus% of the diameter of the solder ball data part from the apex and linearly interpolate between the diameter plus%, or detect minus% of the diameter of the solder ball data part from the apex. The linear interpolation is made between this diameter minus%.
Appropriate values of “plus%” and “minus%” are arbitrary, and the optimum value is determined by the size, height, interval, resolution, etc. of the BGA solder balls.

  As shown in FIG. 13A, when the solder ball surface of the BGA is small and the interval is narrow, the data amount of the solder ball data portion is larger than the data amount of the package portion, and an approximate line is formed in the solder ball data portion. (Non-target approximate line) is drawn, and there is a possibility that the approximate line is not attracted to the target approximate line.

The countermeasures shown in FIGS. 13B and 13C are taken.
That is, a part of the solder ball data part is cut to create a low mountain solder ball data part, and then approximate correction is performed. When there is a ball, the approximate line is pulled to the solder ball data portion, so the warpage correction of the package data portion is performed.
1: The entire inclination is corrected by least square plane correction (FIG. 13B).
2: The solder ball data portion is cut so that the approximate line is as close to the package as possible (FIG. 13C).

  The present invention is utilized in industries that manufacture and use BGA.

1: BGA flatness measuring device,
2: Measuring unit,
3: heating unit,
4: Control unit,
5: Heating unit set part,
6: protrusion,
7: protrusion fitting hole,
8a, 8b: irradiation part,
8a-1 to 8a-n: row light,
8b-1 to 8b-n: tandem light,
9: BGA
10: Package
11, 11-1, 11-2: solder balls,
12: Surface with solder balls,
13: 3D measurement unit,
14: Measuring head,
15: Measurement data,
16, 16-1: Three-dimensional shape data with a ball surface,
17: Three-dimensional shape data creation unit with ball surface,
18: Measurement controller,
20: Solder ball data part,
21, 21-1: Three-dimensional shape data without a ball,
22: Three-dimensional shape data creation unit without a ball,
23: heating unit controller,
24: Monitor
25: heating chamber control data storage unit,
26: Setting instruction section,
27: Output unit,
28: Setting section,
30: reflected light,
31: light receiving part,
32a, 32b: light source,
35: dent,
36: housing
37a, 37b: hot air supply unit,
38a, 38b: Hot air exhaust part,
39: heating chamber,
40: Work set part
41: Base,
42a, 42b: heating means,
43: Two-layer heat-resistant transparent glass,
44: Ceiling board,
45a, 45b: screws with knobs,
46a, 46b: female thread,
47a, 47b: hot air,
48: temperature sensor,
49: Heating chamber control data,
52: Actual furnace heating data storage unit,
54: Three-dimensional shape data storage unit without a ball surface,
55: Three-dimensional shape data storage unit with ball surface,
56: heating chamber temperature,
57: Estimated workpiece temperature,
58-1 to 58n: Solder ball data portion.
59: Measurement time,
60a-1: row data,
60b-1: column data.

Claims (6)

A heating unit having a heating means and a work setting unit, and heating the BGA having a large number of solder balls on a package plane, which is set in the work setting unit, by the heating means;
An irradiating unit for irradiating measurement light toward a surface having a solder ball having the solder ball of the package;
Three-dimensional shape data with a ball for measuring the reflected light of the measurement light irradiated on the surface with the solder ball and generating three-dimensional shape data with a ball, which is the surface three-dimensional shape data of the surface with the solder ball The creation department;
A ball-free surface three-dimensional shape data creating unit that creates a ball-free surface three-dimensional shape data by excluding the solder ball data portion by program processing from the three-dimensional shape data with the ball;
A flatness measuring apparatus for BGA, comprising:   2. The BGA flatness measuring apparatus according to claim 1, wherein the measuring light is striped light. The measurement light is row light and column light,
Row data is obtained by the row light,
Column data is obtained by the column light,
The three-dimensional shape data with the ball is formed by the row data and the column data,
In order to exclude the solder ball data portion from the three-dimensional shape data with the ball,
(1) A row approximation correction is performed in which a row approximation line and a row cut level are drawn with respect to the data of each row of the row data, and a row correction data is generated by excluding a data portion exceeding the row cut level. ,
(2) In the data part excluded by the row correction, the data of the final confirmed row approximate line that has been finalized is put into one row of data,
(3) The processing of (1) and (2) is performed on all row data to create all row approximate correction data,
(4) A column approximation correction is performed in which a column approximation line and a column cut level are drawn with respect to the data of each column of the column data, and column correction data is generated by excluding data portions exceeding the column cut level. ,
(5) In the data part excluded by the column correction, the data of the final confirmed column approximate line is finalized to create one column of data,
(6) All the column data are subjected to the processes (4) and (5) to create all column approximation correction data,
(7) The ball-free surface three-dimensional shape data is created from the all-row approximate correction data and the all-column approximate correction data, according to any one of claims 1 and 2. BGA flatness measuring device.   The row approximation correction and the column for creating a low mountain solder ball data portion in which a part of the solder ball data portion is cut and the solder ball portion is lowered and excluding the low mountain solder ball data portion. 4. A flatness measuring apparatus for a BGA according to claim 3, wherein the processing after the approximate correction is performed. A measurement unit having a heating unit setting unit for setting the heating unit is provided,
The irradiation unit is provided in the measurement unit;
The measurement unit and the heating unit are separated.
The flatness measuring apparatus for a BGA according to any one of claims 1 to 4, wherein the heating unit is set in a detachable form. A heating step for heating the BGA;
A measurement light irradiation step of irradiating the measurement light toward the surface having the solder balls having the BGA solder balls being heated in the heating step;
Three-dimensional shape data with a ball for measuring the reflected light of the measurement light irradiated on the surface with the solder ball and generating three-dimensional shape data with a ball, which is the surface three-dimensional shape data of the surface with the solder ball Creation process,
The ball-free surface 3D shape data, which is the surface 3D shape data of the package without the solder ball data portion, is created by excluding the solder ball data portion by program processing from the ball-side surface 3D shape data Surface 3D shape data creation process;
A BGA flatness measuring method comprising the steps described above.

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