JP2643882B2 - Method and apparatus for evaluating firing state of inorganic substrate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for evaluating a fired state of an inorganic substrate such as a glass ceramic multilayer wiring board, and more particularly to a basic area for calculating positional information (coordinates) and a partial area at the coordinates. The present invention relates to a method for evaluating a fired state of an inorganic substrate, which is prepared by preparing a substrate on which information is formed and using the substrate for an experimental dynamic analysis method, and an apparatus therefor.

[0002]

2. Description of the Related Art Conventional techniques of this type include, for example, an X-ray stress measuring method / measuring device shown in FIG. 6 as an experimental method, and a finite element method shown in FIG. there were. In the X-ray stress measurement method, first, in step S50
In, a measurement sample of several mm square in an unstrained state is prepared, and then, in step S51, the surface of the sample is subjected to a smoothing process such as polishing.

Then, in step S52, an X-ray diffraction angle and a diffraction intensity in an unstrained state are measured by an X-ray stress measuring device. Subsequently, in step S53, a measurement sample also having a size of several mm after firing is prepared. After the surface is smoothed in step S54, the X-ray diffraction angle and diffraction intensity are measured in step S55. Then, in step S56, a distortion value generated after firing is calculated from the X-ray diffraction angle and diffraction intensity before and after firing, and further, in step S57, stress is applied to another substrate whose firing state is known, An elastic constant is obtained by measuring the resulting strain, and in step S58, a stress value is calculated from the elastic constant and the previous strain value.

Alternatively, when using the finite element method, as shown in FIG. 7, in step S60, a mathematical model describing the sintering process is defined theoretically (thermodynamically, kinetic) in advance, and then, In step S61, the stress-strain constituent relation formulated by this mathematical model is verified,
Identification and quantification of parameters (for example, thermal activation energy, reaction rate constant, binder thermal decomposition rate, shrinkage rate, particle size of ceramic particles, sintering shrinkage rate, diffusion coefficient, etc.) appearing in the structural relationship are performed.

[0005] In step S62, after taking into account the effects of changes in stress temperature and strain rate and the identification of high-temperature plasticity phenomena of ceramics, formulating into finite elements is performed, and finite element analysis is performed. Then, in step S63, shape data for finite element analysis is created. Thereafter, in step S64, the parameters, boundary conditions, and firing profile conditions, that is, the temperature and pressure conditions in the degreasing process, heating process, sintering process, and cooling process are set. In step S65, finite element analysis is performed. The strain distribution and stress distribution of the fired substrate were determined.

[0006]

SUMMARY OF THE INVENTION The aforementioned prior art X
In the linear stress measurement method / measuring device, the measurement area is several mm square, so in the evaluation of a glass ceramic multilayer substrate which is usually several tens mm square to several 100 mm square, a part must be cut out from the substrate to produce a measurement sample. Because
At the time of the cutting, the residual stress is released, and a state different from the residual stress of the actual substrate is measured.

Furthermore, since it is necessary to use an X-ray source, qualification and knowledge of X-ray handling are required, and strict control of the X-ray exposure of the operator and the environment around the X-ray stress measuring device are required. Therefore, there is a problem that it is not easy to develop the system in the form of in-line in-process evaluation at a manufacturing site.

On the other hand, regarding the computational mechanical evaluation by the finite element method, the process of sintering glass ceramics from a green state is a kind of phase change process, and a mathematical model describing the elementary process of the phase change. If is not established,
Although the calcined state and mechanical properties of the calcined substrate cannot be obtained by calculation, means and methodologies for determining the mathematical model are still being studied.

If a mathematical model that describes the elementary process of the sintering process is constructed, the simulation result and the actuality of the glass ceramic multilayer substrate having a complicated wiring structure are considered due to the property that the finite element method is a numerical simulation. It is necessary to compare and verify the firing state. However, the verification means is to identify and quantify the thermal activation energy, reaction rate constant, sintering shrinkage rate, binder thermal decomposition rate, diffusion coefficient, etc., which indicate the thermal activation process, and to identify the high temperature plastic phenomena of glass ceramics Any one of them is not technically easy and requires much man-hour.

Therefore, in the conventional finite element method, for a complex system such as a glass ceramic multilayer substrate,
Changes in the firing state (for example, lamination structure, wiring structure, via structure, actual manufacturing conditions, and material characteristics)
It was not possible to quantitatively evaluate the effect on local shape change or strain distribution change). The present invention has been made in view of such a situation, and an object of the present invention is to provide a method and an apparatus capable of accurately evaluating a firing state of an inorganic substrate such as a glass ceramic multilayer substrate by a simple method. It is.

[0011]

According to the present invention, in order to achieve the above object, (1) a portion including a plurality of readable position information and a place corresponding to the position information on an unfired inorganic substrate; And (2) reading the position information and the base area information on the unfired inorganic substrate, storing the information, and corresponding to the position information. Measuring the thickness of the substrate at the place to be stored and storing the thickness information; (3)
Reads the position information and basic area information on the inorganic substrate during or after firing, stores the information, measures the thickness of the inorganic substrate during or after firing at a location corresponding to the position information, and obtains the thickness information. And (4) for the unfired and during or after firing of the inorganic substrate,
Calculating the area at the position from the area basic information and calculating the volume at the position from the calculated area and the thickness information at the position; and (5) the unfired volume and the firing or A method for evaluating the firing state of an inorganic substrate, comprising: comparing the volume after firing with a stage during firing or determining the strain introduced into the substrate after firing.

Further, according to the present invention, (1) basic area information serving as basic data for calculating the position information and partial area formed on the unfired, semi-fired, or fired inorganic substrate formed on the substrate; A reading device for reading
(2) a measuring device for measuring the thickness of the unfired, semi-fired or fired inorganic substrate, (3) a storage device, and (4) position information obtained from the reading device and the measuring device. Processing / storage procedure means for processing basic area information and thickness information and storing the processing result in the storage device; and (5) storing position information, basic area information and thickness information from the storage device. After calculating the volume of each part of the inorganic substrate after reading, unfired and semi-fired or fired, and comparing the volume of each part of the inorganic substrate after semi-fired or fired with that of the unfired inorganic substrate, Analysis procedure means for performing a procedure for calculating the strain introduced into the inorganic substrate and storing the calculated strain data in the storage device; There is provided.

[0013]

Next, embodiments of the present invention will be described with reference to the drawings. [First Embodiment] FIG. 1 is a system configuration diagram in a first embodiment of the present invention, and FIG. 2 is a flowchart showing an evaluation processing procedure when the system is used. First, in step S10, a glass ceramic multilayer substrate 1a before firing is prepared, and then, in step S11, a square lattice pattern having an arbitrary lattice spacing is printed on the substrate surface by screen printing.

In step S12, the coordinates of the grid points before firing are read by the coordinate reading probe 2a of the grid point coordinates reading device 2b comprising a pointing device such as an image scanner or a digitizer, and the coordinates of the substrate thickness measuring device 3b are read. The thickness of the substrate corresponding to each grid point is measured by the thickness measuring probe 3a. Subsequently, in step S13, the read coordinate data and the measured thickness data are stored and stored in the storage device 5 through the analysis device 4 in which the coordinates and thickness data processing / storage procedure means are incorporated.

Next, in step S14, a glass ceramic multilayer substrate 1b during or after firing is prepared, and the grid point coordinates and the thickness of the portion of the substrate 1b corresponding to the grid points are similarly measured. At
The coordinate data and the thickness data are stored in the storage device 5 through the analysis device 4.

Next, in step S16, the grid point coordinate data and the thickness data before firing stored in the storage device 5 are taken out by the analysis procedure means built in the analysis device 4, and each square point data is obtained from the grid point coordinate data. The area for each grid is calculated, and this is integrated in the thickness direction to calculate the volume Vij for each square grid. Next, in step S17, similarly, the grid point coordinate data and the thickness data during or after firing are taken out from the storage device 5 into the analyzer 4, and the area is calculated for each square grid from each grid point coordinate data. Is integrated in the thickness direction to obtain a volume Vi for each square lattice.
j ′ is calculated.

Subsequently, in step S18, the volume distortion ε for each square lattice is determined from the volume value corresponding to the square lattice before firing and each volume value of the square lattice during or after firing.
_Vij is calculated by equation (1). ε _Vij = ln (Vij ′ / Vij) (1)

If the volume strain is calculated over the entire square lattice, it becomes the volume strain distribution generated in the substrate 1b during or after firing. Based on the data of the volume strain distribution, in step S19, the strain gradient g corresponding to the strain difference Δε between any two points and the distance between the two points in the substrate 1b.
rad is calculated according to the equations (2) and (3), respectively. Δε = ε _Vij −ε _Vkn (2) (i, j = 1, 2, 3,...) (K, n = 1, 2, 3,...; | _Ik ) + | J−n | ≠ 0) grad = Δε / d (3) (d: distance between any two points)

Subsequently, in step S20, the residual stress is calculated by multiplying the strain difference Δε by the elastic constant of the substrate 1b during or after firing. Then, step S21
, The analysis device 4 stores all the calculation results in the storage device 5
The graphics display device 6 having a built-in analysis result display procedure means takes out the calculation result from the storage device 5 and displays it graphically. By displaying in this way, the firing state can be visualized, and this can be quantitatively evaluated.

In the above embodiment, the grid pattern of the square grid is screen-printed and the position information is obtained and the area is obtained by using this. However, the pattern to be formed on the substrate is to determine the position. Any pattern other than a square lattice may be used as long as basic data for calculating the area can be obtained. For example, it may be a rectangular lattice pattern or a discrete pattern such as a circle or an ellipse. For example, when using a circle, two orthogonal diameters are measured, and the area is calculated based on the two diameters.
Further, the position of the circle is determined from the intersection of the two diameters.

[Second Embodiment] FIG. 3 is a schematic block diagram showing a configuration of an evaluation system according to a second embodiment of the present invention. FIGS. 4 and 5 show a case where the system is used. motion·
It is the flowchart which showed the processing procedure.

First, as in the case of the first embodiment, in step S30, a substrate having a square lattice pattern printed on the entire surface of the substrate is prepared, and in step S31, grid point coordinates and thickness are measured. Further, in step S32, the data is stored and stored in the storage device 5 through the analysis device 4, and subsequently, in step S33, the volumes Vij and Vij 'of each square lattice before and after firing are calculated. Then, in step S34, the volume distortion ε _Vij is calculated for each of the corresponding square lattices after firing from the above equation (1). Up to this point, the operation is the same as in the first embodiment.

Next, in step S35, an electrical characteristic test and an appearance inspection are performed on the evaluated substrate, and the substrate is evaluated as a non-defective product having no structural defects such as electrical connection failure, cracks and warpage after firing. If it is confirmed that there is, the analysis result of this evaluation is stored and stored in the storage device 5 as a standard result.

Next, in step S36, an arbitrary part of the glass ceramic multilayer substrate (substrate 1a 'before firing) on the production line, which is different from the substrate used for obtaining the standard result, for example, a product As a function, the grid pattern is partially printed on a portion where printing the grid pattern does not hinder or a portion where a defect or a defect is likely to occur structurally.

Next, in step S37, as in the first embodiment, the coordinates of the grid points of the substrate 1a 'before firing and the substrate 1b' after firing are calculated for each of the portions where the grid pattern is printed. Reading is performed by the reading probe 2a and the grid point coordinate reading device 2b, and the thickness of the substrate corresponding to the grid point is measured by the thickness measuring probe 3a and the substrate thickness measuring device 3b. And
In step S38, the volume of each square lattice is calculated for each printed portion of the grid pattern, and in step S39, the volume distortion distribution of each portion is similarly calculated using equation (1).

In step S40, the analysis result is stored in the storage device 5. Then, step S41
In the above, the volume distortion distribution calculated for the fired substrate 1b 'using the comparison operation device 7 incorporating the comparison / collation and difference determination procedure means with the standard result, and the volume distortion distribution of the corresponding standard result Then, in step S42, a difference determination is performed on the magnitude of the difference between the distortion values. As a result, if the difference between the distortion values is acceptable, the process proceeds to step S43, where the compared substrates 1a 'and 1b' are adopted as non-defective products, and in step S44, the graphics display device 6 is determined to be non-defective. Display. Next, the process returns to the next substrate on the production line via step S45, and the same operation is repeated.

In step S42, the compared substrates 1
If the analysis result of a'1b 'is too large compared to the standard result, the process proceeds to step S46, where the graphics display device 6 is displayed as defective, and the firing process conditions are checked (step S47). (Step S48), and the contents of the check are fed back to the design / manufacturing conditions in Step S49.

As described above, in the second embodiment, the evaluation in the in-line in-process is more advanced than in the first embodiment, and the analysis can be performed only by a partial comparison of the volume strain distribution. There is an advantage that the speed is high and good / bad judgment can be made automatically.

[0029]

As described above, according to the present invention, the readable position information and area information are printed on the inorganic substrate before firing, and the data is read and the thickness of the substrate is measured to calculate the volume. And, since the volume is determined by comparing the volume before firing with the volume after firing,
According to the present invention, it is possible to accurately determine the volume strain introduced into the substrate during the firing step by a relatively simple method, and further, using this data, quantitative evaluation of strain gradient, residual stress, and the like. Can be performed.

Further, since it is not necessary to cut the substrate into chips and to use X-rays, it is easy to deploy on a production site, and in-line in-process evaluation becomes possible.
Since it is possible to promptly feed back the firing process conditions and the material composition conditions, it is possible to improve the quality and improve the production stability. Also, Equation 1
A glass ceramic multilayer substrate having a large area of about 00 mm square can be evaluated as it is, and the firing state of the whole can be grasped.
High-precision evaluation can be performed while reducing the number of evaluation steps.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an evaluation system according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a processing procedure in the first embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of an evaluation system according to a second embodiment of the present invention.

FIG. 4 is a first half of a flowchart showing a processing procedure in a second embodiment of the present invention.

FIG. 5 is a latter half of a flowchart showing a processing procedure in the second embodiment of the present invention.

FIG. 6 is a flowchart showing a processing procedure of a conventional X-ray stress measurement method.

FIG. 7 is a flowchart showing a processing procedure of a conventional finite element method.

[Explanation of symbols]

 1a, 1a 'Glass ceramic multilayer substrate before firing 1b, 1b' Glass ceramic multilayer substrate after firing 2a Probe for coordinate reading 2b Grid point coordinate reading device 3a Probe for thickness measurement 3b Substrate thickness measuring device 4 Analysis device 5 Storage device 6 Graphics display device 7 Comparison operation device

Claims (7)

(57) [Claims] (1) A plurality of readable position information and basic area information serving as basic data for calculating an area of a portion including a location corresponding to the position information are printed on an unfired inorganic substrate. And (2) reading position information and basic area information on the unfired inorganic substrate, storing the information, measuring a substrate thickness at a location corresponding to the position information, and storing the thickness information. And (3) reading the position information and the basic area information on the inorganic substrate during or after firing and storing the information, and determining the thickness of the inorganic substrate during or after firing at a location corresponding to the position information. Measuring and storing the thickness information; and (4) calculating the area at the position from the area basic information for the unfired and during or after firing of the inorganic substrate, and calculating the calculated area and the area at the position. Calculating the volume at that position from the thickness information; and (5) comparing the unfired volume with the volume during or after firing to introduce the material into the substrate during the stage during or after firing. Determining a fired state of the inorganic substrate. 2. The method according to claim 1, wherein after the step (5), a step of obtaining a strain gradient from strain information at each position and calculating a residual stress from the obtained strain information is added. 2. The method for evaluating a firing state of an inorganic substrate according to item 1. 3. The distortion introduced into the substrate during or after the firing of the non-defective inorganic substrate, and the strain introduced into the substrate during or after the firing of the test substrate is determined. 2. The method for evaluating the firing state of an inorganic substrate according to claim 1, wherein the quality of the substrate to be inspected is determined by comparing the following. 4. A reading device for reading basic area information, which is basic data for calculating position information and partial area formed on a substrate, of an unfired, semi-fired, or fired inorganic substrate, (2) a measuring device for measuring the thickness of the unfired, semi-fired or fired inorganic substrate, (3) a storage device, and (4) position information obtained from the reading device and the measuring device. Processing / storage procedure means for processing basic area information and thickness information and storing the processing result in the storage device; and (5) position information, basic area information and thickness information from the storage device. Calculate the volume of each part of the inorganic substrate after readout, unfired and semi-fired or fired, and compare the volume of each part of the inorganic substrate after semi-fired or fired with that of the unfired inorganic substrate An analysis procedure means for calculating the distortion introduced in the after semi-sintered or sintered inorganic substrate, the calculated strain data performs a procedure to store in the storage device by Rukoto,
An apparatus for evaluating the sintering state of an inorganic substrate, comprising: 5. The analysis procedure means calculates a strain gradient from the obtained strain of each part, calculates a residual stress from the calculated strain gradient, and stores all or a part of the calculation results in the storage device. The apparatus for evaluating a fired state of an inorganic substrate according to claim 4, further comprising a function of performing a procedure for storing the inorganic substrate. 6. A comparison operation device for comparing the distortion of a non-defective substrate stored in the storage device with the distortion of a substrate to be inspected to judge the quality of the substrate to be inspected. The apparatus for evaluating a firing state of an inorganic substrate according to claim 4. 7. A graphics display device for graphically displaying an analysis result by said analysis procedure means stored in said storage device.
An apparatus for evaluating a firing state of an inorganic substrate as described in the above.