CN107767373A - A kind of chip pin width fast sub-picture element precision visible detection method - Google Patents

Abstract

The invention discloses a kind of chip pin width fast sub-picture element precision visible detection method, in order to lift detection speed, ensure the accuracy of sub-pix simultaneously, when handling chip image, first with the correlation properties of chip prior information, targetedly detection template operator of the design with directional characteristic, then searched for using detection template operator in the normal residing scope of chip pin, obtain two angle points of chip pin top margin, and carry out sub-pixel positioning, the characteristics of according further to known to chip pin direction, using two angle point lines and do chip level direction projection method calculate width, so as to realize that the quick high accuracy of chip pin width detects, the method of the present invention has not only saved calculating content, improve detection speed, it ensure that accuracy simultaneously.

Description

A kind of chip pin width fast sub-picture element precision visible detection method

Technical field

Chip package detection technique field of the present invention, and in particular to a kind of chip pin width based on prior information is quick Sub-pixel precision visible detection method.

Background technology

With the continuous development of manufacture of microchips, throughput rate more and more higher, chip package pin is also more and more, and this gives Current chip pin vision on-line checking brings challenge, and the width of wherein pin is the project that chip size detection must be examined, It is the key technology of modern chips manufacture, in vision-based detection, it usually needs carry out calculating extraction to pin edge, especially push up The information on side.

In common algorithm, typically by setting related template, such as sobel operators click through to image related pixel Row computing, differentiates through threshold value, and marginal point is extracted, and thus carries out least square fitting calculating, obtains edge.This Kind algorithm is applied to the edge extracting of any image, without the priori using chip image, it is therefore desirable to every Individual pixel all carries out complex calculating.

Usual chip determines that its direction, such as the pin top margin on one side are almost in level side in charging substantially To, and positive edge normal presence position should be in a certain constraint, while these pins have more obvious rectangular property Etc., therefore found by theoretical research, by being handled in advance some key messages known to chip pin, can reduce Amount of calculation, and accelerate identification process.

The content of the invention

It is an object of the invention to provide a kind of chip pin width fast sub-picture element precision visible detection method, to lift detection Speed, while ensure the exact value of sub-pix.

To realize above-mentioned technical purpose and the technique effect, the present invention is achieved through the following technical solutions：

A kind of chip pin width fast sub-picture element precision visible detection method, when handling chip image, first with core The correlation properties of piece prior information（I.e. chip often determines its direction substantially in charging, such as the pin top margin on one side is several Be horizontally oriented, and positive edge normal presence position should in a certain constraint, while these pins have it is more bright Aobvious rectangular property etc.）, targetedly detection template operator of the design with directional characteristic, is then calculated using detection template Son search, two angle points of acquisition chip pin top margin in the normal residing scope of chip pin, and sub-pixel positioning is carried out, The characteristics of according further to known to chip pin direction, using two angle point lines and the method for doing chip level direction projection Width is calculated, so as to realize that the quick high accuracy of chip pin width detects, calculating content had both been simplified, and in turn ensure that detection Accuracy.

This method comprises the following steps that：

Step 1）Using CCD camera shooting chip image, to obtain chip visual signal；

Step 2）According to the prior information of chip pin, the image-region that need to be handled is divided；

Step 3）According to the characteristics of chip pin prior information, one detection template for carrying directional characteristic of design, and according to core The size of piece pin sets fan-shaped window size；

Step 4）The left templates on detection template are selected, each pixel is normally traveled through in residing scope in chip pin；

Step 5）Calculate the template operator response value of pixel in area-of-interest；

Step 6）Judge whether response exceedes threshold value according to result of calculation, if it is not, then next pixel is handled, if so, Then carry out in next step；

Step 7）Determine whether response with abscissa moves to left reduction, if it is not, then next pixel is handled, if It is, then an angle point of the current pixel point as chip pin；

Step 8）To near true angle point existing redundancy angle point sub-pix exact position is obtained using the method for average；

Step 9）The right mould plate on detection template is selected, utilizes step 4）To step 8）Method obtain chip pin another Angle point；

Step 10）Projected by two angle point lines of acquisition to horizontal direction and calculate pin width.

The beneficial effects of the invention are as follows：

, it is necessary to higher and higher detection speed and enough precision in the vision-based detection of chip package pin.The present invention is logical Prior information of the chip pin on geometric properties is crossed, reduces and calculates content, compared with other detection algorithms, the present invention only extracts Two angle points of chip pin, and extraction scope carries out range constraint according to prior information, reduces volumes of searches；Simultaneously according to direction Fixed rectangle uses the template of Non-completety symmetry, only detects the graded on diagonal, and half is decreased by almost in content, therefore Calculate directional information that is very fast, while being obtained using detection line positioner, it is not necessary to chip angle is corrected and calculated, because This directly can calculate pin width using the angle point of chip pin outward flange two, further reduce calculating content, improve Calculating speed.

Described above is only the general introduction of technical solution of the present invention, in order to better understand the technological means of the present invention, And can be practiced according to the content of specification, below with presently preferred embodiments of the present invention and coordinate accompanying drawing describe in detail as after. The embodiment of the present invention is shown in detail by following examples and its accompanying drawing.

Brief description of the drawings

Accompanying drawing described herein is used for providing a further understanding of the present invention, forms the part of the application, this hair Bright schematic description and description is used to explain the present invention, does not form inappropriate limitation of the present invention.In the accompanying drawings：

Fig. 1 is the flow chart of detection method；

Fig. 2 is the schematic diagram of the detection template designed by the present invention.

Embodiment

Below with reference to the accompanying drawings and in conjunction with the embodiments, the present invention is described in detail.

It is shown in Figure 1, a kind of chip pin width fast sub-picture element precision visible detection method, to chip image During reason, first with the correlation properties of chip prior information（The core for being commonly designed fluted equipotential due to feeding chip and putting determination Piece fixing device, and the pin top margin with one side are nearly at horizontal direction, and positive edge normal presence position should be at certain In one constraint, while the characteristics such as these pins are generally rectangular, this make it that the orientation of chip and direction are often in detection line It is known, so when obtaining chip visual signal progress image procossing using CCD camera, it is possible to reduce some correlation computations Content）, targetedly design has the detection template operator of directional characteristic, then using detection template operator in chip pin Normal residing scope in search, obtain two angle points of chip pin top margin, and carry out sub-pixel positioning, according further to The characteristics of known to chip pin direction, using two angle point lines and the method calculating width of chip level direction projection is done, from And realize the quick high accuracy detection of chip pin width.

Algorithm is illustrated by taking the top pin top margin detection width value of chip as an example below, comprised the following steps that：

Step 1）Using CCD camera shooting chip image, to obtain chip visual signal；

Step 2）Chip often determines that its direction, such as the pin top margin of chip are almost in level side in charging substantially To, and its positive edge normal presence scope is determination scope, while these pins have more obvious rectangular property etc., on State these constraintss and be collectively referred to as prior information, therefore according to these prior informations of chip pin to the image district that need to handle Domain is divided；

Step 3）By searching for the angle point of top pin top margin since in the normal range (NR) residing for chip pin, two angles are obtained After the sub-pix of point is accurately positioned, it can be projected by two angle point lines in chip level direction, so as to obtain width value, Therefore, the characteristics of should being nearby one jiao of rectangle according to chip top pin top corner point, design an inspection with directional characteristic Template is surveyed, sets fan-shaped window size；It is shown in Figure 2, two templates in left and right are included on the detection template, left and right two Template corresponds to left and right two angles detection respectively, it can be seen that this detection template major embodiment is shade of gray on diagonal Change；

Step 4）Left templates are selected, each pixel is normally traveled through in residing scope in chip pin；

Step 5）Utilize the response formula of Non-completety symmetry template operator：, calculate area-of-interest in pixel template Operator response value；Wherein I (i+p, j+q) is the gray scale of pixel in the window of left templates middle and lower part, and I (i-p, j-q) is mutually to tackle Claim the value of point；

Step 6）According to the result of calculation of above-mentioned response formula, judge whether response exceedes threshold value, if it is not, then return to step 5）, next pixel is handled, if so, then using the pixel as candidate angular；

Step 7）In order to reject the point inside edge line, determine whether the response of pixel of candidate angular whether with horizontal seat Mark moves to left reduction, if it is not, then return to step 5）, next pixel is handled, if so, then regarding the pixel of the candidate angular For an angle point of chip top pin top margin；

Step 8）Can typically there is certain redundancy angle point near true angle point, therefore redundancy angle point is obtained using the method for average Sub-pix exact position；

Step 9）Right mould plate is selected, utilizes step 4）To step 8）Method obtain another angle point of chip top pin top margin；

Step 10）Projected by two angle point lines of acquisition to horizontal direction and calculate pin width.

The preferred embodiments of the present invention are the foregoing is only, are not intended to limit the invention, for the skill of this area For art personnel, the present invention can have various modifications and variations.Within the spirit and principles of the invention, that is made any repaiies Change, equivalent substitution, improvement etc., should be included in the scope of the protection.

Claims (1)

1. a kind of chip pin width fast sub-picture element precision visible detection method, it is characterised in that handled to chip image When, first with the correlation properties of chip prior information, targetedly design has the detection template operator of directional characteristic, so Search for, obtain two angle points of chip pin top margin in the normal residing scope of chip pin using detection template operator afterwards, And sub-pixel positioning is carried out, the characteristics of according further to known to chip pin direction, using two angle point lines and do chip The method of horizontal direction projection calculates width, so as to realize that the quick high accuracy of chip pin width detects；

This method comprises the following steps that：

Step 1）Using CCD camera shooting chip image, to obtain chip visual signal；

Step 2）According to the prior information of chip pin, the image-region that need to be handled is divided；

Step 3）According to the characteristics of chip pin prior information, one detection template for carrying directional characteristic of design, and according to core The size of piece pin sets fan-shaped window size；

Step 4）The left templates on detection template are selected, each pixel is normally traveled through in residing scope in chip pin；

Step 5）Calculate the template operator response value of pixel in area-of-interest；

Step 6）Judge whether response exceedes threshold value according to result of calculation, if it is not, then next pixel is handled, if so, Then carry out in next step；

Step 7）Determine whether response with abscissa moves to left reduction, if it is not, then next pixel is handled, if It is, then an angle point of the current pixel point as chip pin；

Step 8）To near true angle point existing redundancy angle point sub-pix exact position is obtained using the method for average；

Step 9）The right mould plate on detection template is selected, utilizes step 4）To step 8）Method obtain chip pin another Angle point；

Step 10）Projected by two angle point lines of acquisition to horizontal direction and calculate pin width.