JP2000028752A - Method for detecting foreign object on photo detector - Google Patents

Method for detecting foreign object on photo detector

Info

Publication number
JP2000028752A
JP2000028752A JP10192602A JP19260298A JP2000028752A JP 2000028752 A JP2000028752 A JP 2000028752A JP 10192602 A JP10192602 A JP 10192602A JP 19260298 A JP19260298 A JP 19260298A JP 2000028752 A JP2000028752 A JP 2000028752A
Authority
JP
Japan
Prior art keywords
light receiving
light
receiving element
foreign matter
output
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP10192602A
Other languages
Japanese (ja)
Inventor
Shinya Harada
晋也 原田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Rohm Co Ltd
Original Assignee
Rohm Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Rohm Co Ltd filed Critical Rohm Co Ltd
Priority to JP10192602A priority Critical patent/JP2000028752A/en
Publication of JP2000028752A publication Critical patent/JP2000028752A/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/94—Investigating contamination, e.g. dust

Abstract

PROBLEM TO BE SOLVED: To quickly and inexpensively inspect whether a foreign objects exists or not on a photo detector with a plurality of light reception parts that are capable of taking out output independently. SOLUTION: Output values V1/S1-V6/S6 being converted per unit area in each of light reception parts 1a-1f are obtained from output values V1-V6 being outputted by applying light L to the entire surface of a photo detector 1 that independently has light reception parts 1a-1f with an area ratio of S1-S6 for outputting an output value by exposure to light, and then the obtained output values are compared, thus detecting whether a foreign object exists or not on the photo detector 1.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は、受光素子を有する
受光用ＩＣ等の検査方法に関し、特に透明パッケージで
覆われて、複数の受光部を有した受光素子上にある異物
の有無を検査する異物検出方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for inspecting a light receiving IC having a light receiving element, and more particularly to a method for inspecting a light receiving element covered with a transparent package and having a plurality of light receiving portions for foreign matter. The present invention relates to a foreign object detection method.

【０００２】[0002]

【従来の技術】光センサ等の受光用ＩＣに形成される受
光素子は、光を受光すると受光した光量に応じて電圧等
に変換されて出力が取り出せるようになっている。従っ
て、受光素子と受光素子を保護する透明パッケージとの
境界や該透明パッケージ内にごみなどの異物が混入する
とその部分の光が遮蔽され、受光素子が光を受光した際
に所望の出力を得られなくなる。このため受光素子の上
面を透明パッケージで覆った後に、受光素子上の異物の
有無を検査する必要がある。2. Description of the Related Art When a light receiving element formed in a light receiving IC such as an optical sensor receives light, the light is converted into a voltage or the like in accordance with the amount of light received, and an output can be taken out. Therefore, if foreign matter such as dust enters the boundary between the light receiving element and the transparent package that protects the light receiving element or foreign matter such as dust enters the transparent package, the light in that part is blocked, and a desired output is obtained when the light receiving element receives the light. Can not be. For this reason, after covering the upper surface of the light receiving element with the transparent package, it is necessary to inspect for the presence of foreign matter on the light receiving element.

【０００３】従来の受光素子上の異物検出方法には、第
１の方法として、顕微鏡等による目視検査する方法があ
る。第２の方法として、ＣＣＤカメラ等により得た検査
対象の受光素子の画像と、予め記憶された異物のない受
光素子の画像との比較を画像処理装置によって行う方法
がある。第３の方法として、図１に示すように受光素子
１にレーザー光等のスポット光２を照射しながら矢印Ｂ
のようにスキャンして受光素子１にスポット光２が当た
らない部分があるかどうかを調べる方法がある。As a conventional method for detecting foreign matter on a light receiving element, there is a first method of visually inspecting with a microscope or the like. As a second method, there is a method in which an image processing device compares an image of a light receiving element to be inspected obtained by a CCD camera or the like with a previously stored image of a light receiving element having no foreign matter. As a third method, as shown in FIG. 1, while irradiating the light receiving element 1 with a spot light 2 such as a laser beam, the arrow B
There is a method of checking whether there is a portion where the spot light 2 does not hit the light receiving element 1 by scanning as shown in FIG.

【０００４】[0004]

【発明が解決しようとする課題】しかしながら、上記第
１の方法は、小さな異物の有無を検査する検査精度を向
上させるために顕微鏡倍率を上げると視野が狭くなって
受光素子全面を検査するのに時間がかかってしまうとい
う問題がある。また、上記第２の方法は、高価な画像処
理装置を必要とするために製造コストを増加させるとい
う問題がある。また、上記第３の方法は、レーザー光等
を発生させる高価な装置を必要として製造コストを増加
させるとともに、受光素子１の全面をスキャンするため
検査時間がかかってしまう問題がある。However, in the first method, when the microscope magnification is increased in order to improve the inspection accuracy for inspecting the presence or absence of small foreign matter, the field of view becomes narrow and the entire light receiving element is inspected. There is a problem that it takes time. Further, the second method has a problem in that an expensive image processing apparatus is required, and thus the manufacturing cost is increased. In addition, the third method has a problem that an expensive device for generating laser light or the like is required, so that the manufacturing cost is increased and an inspection time is required because the entire surface of the light receiving element 1 is scanned.

【０００５】本発明は、独立して出力を取り出すことの
できる複数の受光部を有した受光素子に対して、短時間
で安価に受光素子上の異物の有無を検査することができ
る受光素子上の異物検出方法を提供することを目的とす
る。The present invention is directed to a light-receiving element having a plurality of light-receiving portions from which outputs can be independently taken out, which can be inspected for foreign substances on the light-receiving element in a short time and at low cost. It is an object of the present invention to provide a method for detecting foreign matter.

【０００６】[0006]

【課題を解決するための手段】上記目的を達成するため
に請求項１に記載の発明は、受光により出力値を独立に
出力する受光部を複数有する受光素子の全面に光を照射
し、各受光部における単位面積当たりに換算した出力値
を比較することによって該受光素子上の異物の有無を検
知するようにしたことを特徴としている。Means for Solving the Problems In order to achieve the above object, the invention according to claim 1 irradiates light to the entire surface of a light receiving element having a plurality of light receiving sections that independently output an output value by receiving light. It is characterized in that the presence or absence of foreign matter on the light receiving element is detected by comparing output values converted per unit area in the light receiving unit.

【０００７】この構成によると、受光素子全面に強さの
均一な光が照射され、各受光部の面積に比例した受光量
に応じた電圧等が各受光部から出力される。受光素子上
に異物がなければ各出力値を単位面積当たりに換算した
各換算値は同じになるが、いづれかの受光部上に異物が
あると、その受光部からの出力値を単位面積当たりに換
算した換算値が他の受光部の換算値に比して小さくな
る。これにより受光素子上の異物の有無を調べることが
可能となる。ここで出力に影響を与えないような微細な
異物については無視している。According to this configuration, the entire surface of the light receiving element is irradiated with light having a uniform intensity, and a voltage or the like is output from each light receiving unit in accordance with the amount of light received in proportion to the area of each light receiving unit. If there is no foreign matter on the light-receiving element, the converted values obtained by converting each output value per unit area will be the same, but if there is a foreign matter on any of the light-receiving parts, the output value from that light-receiving part will be per unit area. The converted value becomes smaller than the converted values of the other light receiving units. This makes it possible to check the presence or absence of foreign matter on the light receiving element. Here, fine foreign substances that do not affect the output are ignored.

【０００８】[0008]

【発明の実施の形態】本発明の実施形態を図を参照して
説明する。図２の（ａ）、（ｂ）はＣＤ用のピックアッ
プ部に用いられる受光用ＩＣの概略を示す上面図及び側
面断面図である。受光用ＩＣ（１０）は基板３上に受光
素子１が形成され、その上部を透明のパッケージ４で覆
っている。受光素子１はＣＤ用ピックアップの場合には
同じ面内（１ｓ）に受光面を有する６個の受光部１ａ、
１ｂ、１ｃ、１ｄ、１ｅ、１ｆから成り、受光面１ｓに
光が当たると各受光部に対応する端子（不図示）から別
々に出力が取り出せるようになっている。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. 2A and 2B are a top view and a side sectional view schematically showing a light receiving IC used in a pickup unit for a CD. The light receiving IC (10) has a light receiving element (1) formed on a substrate (3), and its upper part is covered with a transparent package (4). In the case of a CD pickup, the light receiving element 1 includes six light receiving sections 1a having a light receiving surface in the same plane (1s).
1b, 1c, 1d, 1e, and 1f. When light strikes the light receiving surface 1s, outputs can be separately taken out from terminals (not shown) corresponding to the respective light receiving sections.

【０００９】図３は受光用ＩＣ（１０）の受光素子１上
の異物の有無の検査を自動的に行う検査システムの概略
構成図である。被検査物３０（受光用ＩＣ（１０））
は、ハンドラー２６によって治具２７上に設けられたソ
ケット２７ａに装着され、ＩＣテスター２０によりケー
ブル３１ｂを通じて各受光部の出力を受け取って受光素
子１上の異物の有無を検査して良否が判定される。その
結果がケーブル３１ａを通じてハンドラー２６に送られ
てハンドラー２６により所定位置に搬送される。FIG. 3 is a schematic configuration diagram of an inspection system for automatically inspecting the presence or absence of foreign matter on the light receiving element 1 of the light receiving IC (10). Inspection object 30 (light receiving IC (10))
Is mounted on the socket 27a provided on the jig 27 by the handler 26, receives the output of each light receiving section through the cable 31b by the IC tester 20, and inspects the presence or absence of foreign matter on the light receiving element 1 to determine pass / fail. You. The result is sent to the handler 26 through the cable 31a, and is conveyed to a predetermined position by the handler 26.

【００１０】以下に図４、図５に示す検査システムのブ
ロック図及びフローチャートにより検査システムの動作
順序を説明する。まずステップ１１０で予めＩＣテスタ
ー２０の入力部２１によって各受光部１ａ〜１ｆの面積
比Ｓ１、Ｓ２、Ｓ３、Ｓ４、Ｓ５、Ｓ６を入力して、入
力された面積比Ｓ１〜Ｓ６をステップ１２０で記憶部２
３に記憶しておく。ステップ１３０で被検査物３０（受
光用ＩＣ）が治具２７にセットされるまで待機する。Hereinafter, the operation sequence of the inspection system will be described with reference to the block diagrams and flowcharts of the inspection system shown in FIGS. First, in step 110, the area ratios S1, S2, S3, S4, S5, and S6 of the light receiving units 1a to 1f are input in advance by the input unit 21 of the IC tester 20, and the input area ratios S1 to S6 are determined in step 120. Storage unit 2
3 is stored. In step 130, the process waits until the inspection object 30 (light receiving IC) is set on the jig 27.

【００１１】被検査物３０が治具２７にセットされると
インターフェース２５を通じてＩＣテスター２０に通信
され、ステップ１４０で光源２８によって受光素子１に
強さの均一な平行の光Ｌが照射されるとともに、光Ｌを
受光した各受光部１ａ〜１ｆから出力される電圧Ｖ1、
Ｖ2、Ｖ3、Ｖ4、Ｖ5、Ｖ6がＣＰＵ２２に送られる。各
受光部１ａ〜１ｆの面積比Ｓ１〜Ｓ６を例えば受光部１
ａ、１ｂではＳ１，Ｓ２＝４に対し受光部１ｃ、１ｄ、
１ｅ、１ｆではＳ３〜Ｓ６＝１とすると、受光素子１上
に異物Ｄがない場合には受光量は受光面積に比例し、出
力電圧は受光量に比例するので、出力電圧はＶ1＝Ｖ2＝
４Ｖ3＝４Ｖ4＝４Ｖ5＝４Ｖ6の関係に出力される。When the inspection object 30 is set on the jig 27, it is communicated to the IC tester 20 through the interface 25. In step 140, the light source 28 irradiates the light receiving element 1 with parallel light L having a uniform intensity. , A voltage V1 output from each of the light receiving units 1a to 1f that have received the light L,
V2, V3, V4, V5, and V6 are sent to the CPU 22. For example, the area ratios S1 to S6 of the light receiving sections 1a to 1f
In a and 1b, the light receiving sections 1c and 1d for S1 and S2 = 4.
Assuming that S3 to S6 = 1 in 1e and 1f, if there is no foreign matter D on the light receiving element 1, the received light amount is proportional to the light receiving area and the output voltage is proportional to the received light amount, so that the output voltage is V1 = V2 =
It is output in a relation of 4V3 = 4V4 = 4V5 = 4V6.

【００１２】そして、ステップ１５０で出力電圧Ｖ1〜
Ｖ6のいづれかが所定値より小さいと被測定物３０は不
良としており、ここでは極端に出力電圧が低く、大きな
異物Ｄがあるような不良を省いて以下のステップを行わ
ないようにして検査時間の短縮を図っている。出力電圧
Ｖ1〜Ｖ6がいづれも所定値より大きいとステップ１６０
に移行し、単位面積当たりに換算した各受光部の出力電
圧（以下「換算値」という）ａｉ＝Ｖｉ／Ｓｉ（ｉ＝１
〜６）がＣＰＵ２４で演算される。上記の例ではその換
算値は全てａｉ＝Ｖ1／４（ｉ＝１〜６）となってい
る。Then, at step 150, the output voltages V1 to V1
If any one of V6 is smaller than a predetermined value, the device under test 30 is determined to be defective. In this case, the output voltage is extremely low, and a defect such as a large foreign matter D is omitted. We are trying to shorten it. If any of the output voltages V1 to V6 is larger than a predetermined value, step 160
And the output voltage (hereinafter referred to as “converted value”) of each light receiving unit converted per unit area ai = Vi / Si (i = 1
To 6) are calculated by the CPU 24. In the above example, the converted values are all ai = V1 / 4 (i = 1 to 6).

【００１３】また、前述の図２に示すように受光部１ｂ
上に異物Ｄがある場合には、異物Ｄによって光Ｌが遮ら
れる分だけ受光部１ｂの受光量が減少する。従って出力
電圧はＶ1＝４Ｖ3＝４Ｖ4＝４Ｖ5＝４Ｖ6＞Ｖ2の関係に
出力され、ＣＰＵ２４で演算される単位面積当たりに換
算した各受光部の出力電圧（換算値）は、受光部１ｂ以
外の全てはＶ1／４となり、受光部１ｂではａ２＝Ｖ2／
４（＜Ｖ1／４）となる。Also, as shown in FIG.
When the foreign matter D is present above, the amount of light received by the light receiving unit 1b is reduced by the amount by which the light L is blocked by the foreign matter D. Accordingly, the output voltage is output in the relationship of V1 = 4V3 = 4V4 = 4V5 = 4V6> V2, and the output voltage (converted value) of each light receiving unit calculated by the CPU 24 per unit area is all except the light receiving unit 1b. Is V1 / 4, and in the light receiving portion 1b, a2 = V2 /
4 (<V1 / 4).

【００１４】そして、ステップ１７０でａ１〜ａ６の内
で所定値より小さい換算値があると不良となり、ａ１〜
ａ６がいづれも所定値以上であるとステップ１８０へ移
行する。この所定値は上記の例ではＶ1／４ とすればよ
いが、光源の強さの変動等によって受光部１ａ〜１ｆの
受光量が変動するため、Ｖ1〜Ｖ6は測定毎に異なった値
になる。従って、この所定値を一定値に決められないの
で低い値とし、ステップ１５０で省くことのできなかっ
た受光面積の大きな受光部に大きな異物Ｄがある場合等
の極端に換算値の小さい不良を省いている。In step 170, if there is a conversion value smaller than a predetermined value among a1 to a6, it becomes defective, and
If a6 is equal to or more than the predetermined value, the process proceeds to step 180. The predetermined value may be set to V1 / 4 in the above example, but since the amount of light received by the light receiving sections 1a to 1f fluctuates due to fluctuations in the intensity of the light source or the like, V1 to V6 become different values for each measurement. . Therefore, the predetermined value cannot be determined to be a fixed value, so that the predetermined value is set to a low value, and a defect having an extremely small converted value such as a case where a large foreign matter D is present in a light receiving portion having a large light receiving area which cannot be eliminated in step 150 is eliminated. Have been.

【００１５】次にステップ１８０及びステップ１９０に
おいて、ＣＰＵ２４で６つの換算値ａ１〜ａ６を比較す
る。比較の方法として、各換算値の差δ１＝ａｉ−ａｊ
（ｉ＝１、ｊ＝２〜６）を計算してその差が０以外の場
合があると不良とすればよいが、実際には出力電圧Ｖ１
〜Ｖ６には測定誤差が含まれるので異物が無くても換算
値の差は０にならない場合がある。Next, in steps 180 and 190, the CPU 24 compares the six converted values a1 to a6. As a method of comparison, a difference δ1 = ai−aj of each converted value
If (i = 1, j = 2 to 6) is calculated and the difference is other than 0, it may be determined to be defective, but actually, the output voltage V1
Since V6 includes a measurement error, the difference between the converted values may not be zero even if there is no foreign matter.

【００１６】従って、上記差δ１が許容誤差の範囲を良
品とする必要があるが、各換算値ａ１〜ａ６は光源の強
さ等によって変動するので上記差δ１に対して許容誤差
を決めると実質的な範囲が変動する。これを防止するた
めに、ステップ１８０で換算値ａ１〜ａ６の平均値Ａを
計算し、ステップ１９０で上記差δ１と平均値Ａとの比
δ＝(ａｉ−ａｊ)／Ａの絶対値に対して所定の許容量δ
０を決めて、許容量δ０よりも上記比δの絶対値が大き
い場合がある被検査物３０を不良としている。Therefore, it is necessary to make the range of the allowable error of the difference δ1 acceptable. However, since the conversion values a1 to a6 fluctuate depending on the intensity of the light source and the like, if the allowable error is determined for the difference δ1, it is practical. Range varies. To prevent this, the average value A of the converted values a1 to a6 is calculated in step 180, and in step 190, the ratio δ of the difference δ1 and the average value A is calculated based on the absolute value of δ = (ai−aj) / A. Predetermined allowance δ
0 is determined, and the inspection object 30 in which the absolute value of the ratio δ may be larger than the allowable amount δ0 is determined to be defective.

【００１７】更に比δに対して許容量δ０を決めている
のでｉ＝１、ｊ＝２〜６とすると、 δ０＞＝ＡＢＳ［（ａ１−ａ２）／Ａ］ ・・(1) かつ δ０＞＝ＡＢＳ［（ａ１−ａ３）／Ａ］ ・・
(2) かつ δ０＜ＡＢＳ［（ａ２−ａ３）／Ａ］ ・・
(3) （ＡＢＳ［］は絶対値を示す） のような場合に、式(3)の計算が行われずに被検査物３
０が良品となってしまうため、比δ＝（ａｉ−ａｊ）／
Ａにおいてｉ，ｊ＝１〜６、ｉ＞ｊとする方がよい。Further, since an allowable amount δ0 is determined for the ratio δ, if i = 1 and j = 2 to 6, δ0> = ABS [(a1-a2) / A] (1) and δ0> = ABS [(a1-a3) / A]
(2) And δ0 <ABS [(a2-a3) / A]
(3) (ABS [] indicates an absolute value) In the case of
Since 0 is a non-defective product, the ratio δ = (ai−aj) /
In A, it is better to set i, j = 1 to 6, i> j.

【００１８】ｉ，ｊが全ての場合についてδ０＞＝δと
なるとステップ２００で良品と判定され、１回でもδ０
＜δとなるとステップ２１０で不良と判定される。そし
て、判定結果を表示部２２に表示するとともに、記憶装
置２９及びハンドラー２６に送信してデータ保存及び、
良品，不良品の各収納位置への搬送を行った後ステップ
１３０で待機する。When δ0> = δ in all cases where i and j are all equal, it is determined as non-defective in step 200, and δ0 is determined at least once.
If &lt;&dgr;, it is determined to be defective in step 210. Then, the determination result is displayed on the display unit 22 and transmitted to the storage device 29 and the handler 26 to save the data and
After the non-defective product and the defective product have been transported to the respective storage positions, the process waits at step 130.

【００１９】以上に説明したように、単位面積当たりに
換算した出力電圧を比較して、他の受光部に対して小さ
い出力電圧となっている受光部の有無を調べることによ
って受光素子１上に異物があるかどうかを検出すること
が可能となる。As described above, the output voltage converted per unit area is compared, and the presence or absence of a light receiving unit having a smaller output voltage with respect to other light receiving units is checked. It is possible to detect whether or not there is a foreign substance.

【００２０】受光素子１に照射される光Ｌは、その強さ
や照射角度が変化しても受光素子１内で均一であれば、
異物のない時の各受光部１ａ〜１ｆの受光量の比は各受
光部の面積の比となる。その結果、単位面積当たりに換
算した各受光部の出力電圧（換算値）は一定値となり、
異物があったときに一部の換算値が低下することによっ
て判別することができるので、メンテナンスが簡単で、
高価な装置を必要とすることなく短時間に受光素子１上
の異物の有無を検出することが可能となる。The light L applied to the light receiving element 1 is uniform within the light receiving element 1 even if its intensity or irradiation angle changes.
The ratio of the amount of light received by each of the light receiving units 1a to 1f when there is no foreign substance is the ratio of the area of each light receiving unit. As a result, the output voltage (converted value) of each light receiving unit converted per unit area becomes a constant value,
When a foreign substance is present, it can be determined by a decrease in a part of the conversion value, so that maintenance is easy and
It is possible to detect the presence or absence of a foreign substance on the light receiving element 1 in a short time without requiring an expensive device.

【００２１】また、出力に影響を及ぼさないような微細
な異物が受光素子上にあっても受光用ＩＣの性能は満足
されるので異物と見なさない方が都合がよいが、本発明
の方法によると微細な異物が受光素子１上にあっても各
受光部の出力電圧から求められる換算値が許容範囲内で
あると無視されるので、受光用ＩＣの検査精度を向上さ
せることもできるようになる。Further, even if minute foreign matter which does not affect the output is present on the light receiving element, the performance of the light receiving IC is satisfied. Therefore, it is convenient not to regard the foreign matter as a foreign matter. Even if minute foreign matter is present on the light receiving element 1, the conversion value obtained from the output voltage of each light receiving unit is ignored as being within an allowable range, so that the inspection accuracy of the light receiving IC can be improved. Become.

【００２２】本実施形態では受光素子１に照射する光の
強さや照射角度等を受光素子１の全面に対して均一とし
ているが、均一に照射することが困難な場合には、予め
異物のない受光素子１に光を照射して各受光部１ａ〜１
ｆから出力される出力電圧を測定してばらつきを調べ、
その結果に基づいて各受光部１ａ〜１ｆに対して出力電
圧を補正するようにしてもよい。In the present embodiment, the intensity and the irradiation angle of the light illuminating the light receiving element 1 are made uniform over the entire surface of the light receiving element 1. However, when it is difficult to irradiate the light uniformly, there is no foreign matter in advance. The light receiving element 1 is irradiated with light so that each of the light receiving sections 1a to 1
The output voltage output from f is measured to check for variations,
The output voltage may be corrected for each of the light receiving units 1a to 1f based on the result.

【００２３】また、本実施形態では各受光部からの出力
電圧により異物の有無を判断したが電力や電流を各受光
部１ａ〜１ｆから出力させてもよく、各受光部の受光量
に対応する出力値が出力されれば、単位面積当たりに換
算した出力値から同様に異物の有無を判断することがで
きる。In this embodiment, the presence or absence of a foreign object is determined based on the output voltage from each light receiving unit. However, power or current may be output from each of the light receiving units 1a to 1f, and the power or current may be output according to the amount of light received by each light receiving unit. When the output value is output, the presence or absence of a foreign substance can be similarly determined from the output value converted per unit area.

【００２４】更に、本実施形態では受光部からの出力電
圧が受光量に対して比例としたが、出力値が受光量に対
して比例しない場合においても単位面積当たりの受光量
に対応した出力値を求めることができる。例えば出力値
をＥ、受光量をＨ、面積をＳ、ｅ，ｆを定数とすると、 Ｅ＝ｅＨ2 のような関係の場合に、 Ｅ＝ｅ(ｆＳ)2 となり、単位面積当たりの換算した出力値（換算値）を
Ｅ／Ｓ2とするとこの換算値は一定値ｅｆ2となるので、
この換算値が他より小さくなる受光部の有無を調べるこ
とで異物の有無を判断することができる。Further, in this embodiment, the output voltage from the light receiving portion is proportional to the amount of received light. However, even when the output value is not proportional to the amount of received light, the output value corresponding to the amount of received light per unit area can be obtained. Can be requested. For example, if an output value is E, an amount of received light is H, an area is S, and e and f are constants, in the case of a relation such as E = eH 2 , E = e (fS) 2 . If the output value (converted value) is E / S 2 , the converted value becomes a constant value ef 2 ,
The presence or absence of a foreign substance can be determined by examining the presence or absence of the light receiving unit where the converted value is smaller than the others.

【００２５】[0025]

【発明の効果】請求項１の発明によると、受光素子に照
射される光は、その強さや照射角度が変化しても受光素
子内で均一であれば異物があったときに判断することが
できるので、メンテナンスが簡単で、高価な装置を必要
とすることなく短時間に受光素子上の異物の有無を検出
することが可能となる。更に、出力電圧が許容量より小
さくならない微細な異物が受光素子上にあっても無視さ
れるので、受光用ＩＣの検査精度を向上させることがで
きる。According to the first aspect of the present invention, it is possible to judge that there is a foreign substance if the light irradiated to the light receiving element is uniform within the light receiving element even if the intensity or the irradiation angle changes. Since it is possible to perform maintenance, it is possible to detect the presence or absence of a foreign substance on the light receiving element in a short time without requiring an expensive device. Furthermore, since fine foreign matter whose output voltage does not become smaller than the allowable amount is ignored even on the light receiving element, the inspection accuracy of the light receiving IC can be improved.

【図面の簡単な説明】[Brief description of the drawings]

【図１】 従来の受光素子上の異物検出方法を説明す
る図である。FIG. 1 is a diagram illustrating a conventional method for detecting foreign matter on a light receiving element.

【図２】 本発明にかかる受光素子上の異物検出方法
を説明する図である。FIG. 2 is a diagram illustrating a method for detecting foreign matter on a light receiving element according to the present invention.

【図３】 本発明にかかる受光素子上の異物検出方法
用いた検査システムの概略構成図である。FIG. 3 is a schematic configuration diagram of an inspection system using a method for detecting foreign matter on a light receiving element according to the present invention.

【図４】 本発明にかかる受光素子上の異物検出方法
用いた検査システムのブロック図である。FIG. 4 is a block diagram of an inspection system using the method for detecting foreign matter on a light receiving element according to the present invention.

【図５】 本発明にかかる受光素子上の異物検出方法
用いた検査システムのフローチャートである。FIG. 5 is a flowchart of an inspection system using the method for detecting foreign matter on a light receiving element according to the present invention.

【符号の説明】[Explanation of symbols]

１ 受光素子 １ａ、１ｂ、１ｃ、１ｄ、１ｅ、１ｆ 受光部 ４ パッケージ １０ 受光用ＩＣ ２０ ＩＣテスター ２６ 光源 Ｄ 異物 Reference Signs List 1 light receiving element 1a, 1b, 1c, 1d, 1e, 1f light receiving section 4 package 10 light receiving IC 20 IC tester 26 light source D foreign matter

Claims (1)

【特許請求の範囲】[Claims] 【請求項１】 受光により出力値を独立に出力する受光
部を複数有する受光素子の全面に光を照射し、各受光部
における単位面積当たりに換算した出力値を比較するこ
とによって該受光素子上の異物の有無を検知するように
したことを特徴とする受光素子上の異物検出方法。1. A light-receiving element having a plurality of light-receiving portions for independently outputting output values by receiving light, irradiating light to the entire surface, and comparing the output values converted per unit area in each light-receiving portion, thereby comparing the output values with each other. A method for detecting foreign matter on a light receiving element, wherein the presence or absence of foreign matter is detected.
JP10192602A 1998-07-08 1998-07-08 Method for detecting foreign object on photo detector Pending JP2000028752A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10192602A JP2000028752A (en) 1998-07-08 1998-07-08 Method for detecting foreign object on photo detector

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10192602A JP2000028752A (en) 1998-07-08 1998-07-08 Method for detecting foreign object on photo detector

Publications (1)

Publication Number Publication Date
JP2000028752A true JP2000028752A (en) 2000-01-28

Family

ID=16294003

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10192602A Pending JP2000028752A (en) 1998-07-08 1998-07-08 Method for detecting foreign object on photo detector

Country Status (1)

Country Link
JP (1) JP2000028752A (en)

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