JPS6162844A - Method for inspecting surface appearance of semiconductive resin sealed molded product - Google Patents

Abstract

PURPOSE:To evaluate the contamination degree of the surface appearance state of a semiconductive resin molded product by the reflection quantity of light, by irradiating the surface of the molded product with light by a glossmeter. CONSTITUTION:A semiconductive resin sealed molded product 1 is held to a holding and moving apparatus 2 and a constant quantity of light is allowed to irradiate the semiconductive resin sealed molded product 1 through an optical fiber 4 from a light source 5. The reflected light from the semiconductive resin sealed molded product 1 reaches a light receiver 8 through an optical fiber 7 to be inputted to a multiplexer through an amplifier and inputted to a binarization circuit. The reflected light is successively compared with the output value of the binarization circuit by an operational control part preliminarily storing reference data and, at the time of non-coincidence, an inferior product is rejected.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to the appearance of semiconductor resin-encapsulated molded products, which is characterized in that the appearance surface condition of semiconductor resin-encapsulated molded products is evaluated by the amount of light reflected. The present invention relates to a surface inspection method.

The purpose is to check the surface soiling condition of the molded product.
To provide a method for quickly and accurately quantitatively measuring and automatically determining the degree of dirt.

[Prior art]

Conventionally, the degree of surface contamination of semiconductor resin-encapsulated molded products has been evaluated by visual inspection by each individual.

However, visual judgment is subjective and has large individual differences, and because it is qualitative, the judgment criteria may naturally change gradually over time, even if it is for the same person, or the condition of the lighting in the examination room may change. There were many problems, such as the fact that it was extremely inaccurate, as the viewpoint changed depending on the situation, and it was inefficient, requiring a large number of people and time to perform the test.

[Purpose of the invention]

The present invention aims to improve the appearance and surface condition of semiconductor resin-sealed molded products, which has conventionally been difficult to objectively and stationarily judge. As a result of our research aimed at quickly and accurately determining the amount of light reflected, we discovered that the appearance and surface condition of semiconductor resin-sealed molded products could be quantified by measuring the amount of light reflected, and based on this knowledge, we The present invention was completed after extensive research. Its purpose is to seal the semiconductor phase 11t4■
(-Not only does the product value improve due to the beauty and ugliness of the molded product, but when the surface of the molded product begins to get dirty during the production process, the mold coating M1 also gets dirty, causing poor mold releasability and poor addressability. The purpose is to solve problems such as the problem of the molded product falling down or the problem of poor marking performance and printing being impossible if the surface of the molded product is soiled.

[Structure of the invention]

The present invention is a method for inspecting the appearance and surface of a semiconductor resin-sealed molded product, which is characterized in that the appearance and surface condition of the semiconductor resin-sealed molded product is evaluated based on the amount of light reflected.

That is, the present invention irradiates the surface of a semiconductor resin-sealed molded product with a certain amount of light and measures the amount of reflected light to evaluate the degree of contamination on the surface of the molded product. It is better to have as high a reflectance as possible, and it is better to have as low an IJ reflectance as possible for materials that should originally have a satin surface.

The reference value of the foul rate, which serves as the evaluation standard or judgment standard, is determined based on the characteristics of each product, the producer's goals, the user's requirements, etc.

In the present invention, there are many methods for irradiating the surface of a molded product with light and measuring the reflected light. For example, there are no particular limitations, but for example, the surface of the molded product is irradiated with light at an angle of 60 degrees using a so-called glossy needle. However, one method is to receive the reflected light at an angle of 60 degrees and measure its reflectance (ratio of the amount of reflected light to the amount of irradiated light). In this case, measurements are made spot-wise, and large molded products require multiple measurements. Therefore, there is also a method in which, for example, a large number of shiny needles or a large number of light sources and light receivers are lined up and the entire surface of the molded product is measured at one time. Alternatively, there is a method in which, for example, a continuously produced molded product is moved on a belt and irradiated with light from a plurality of optical fiber light sources, and the light is scanned by a plurality of optical fiber receivers and measured.

Hereinafter, the present invention will be described in detail based on embodiments and with reference to drawings.

As shown in the figure, a semiconductor encapsulating resin molded product (1) is held at a fixed position and moved by a holding and moving device (2).

This holding/moving device f (2) is installed so as to hold only the pin portion (20) of the semiconductor encapsulating resin molded product (1) in close contact with each other, and moves in the direction of the arrow (13). It looks like this. An optical fiber support part (3) is installed at the top.
I'm getting fucked. The lower surface (1o) of the optical fiber support part (3)
) and the semiconductor-based IF resin-3 held by the holding and moving device N (2) = The surfaces (11) of the molded product (1) are provided so as to be parallel to each other. Furthermore, the optical fiber support part (3) is provided with a plurality of optical fibers (4) and (7), and the arrangement direction of these optical fibers (4) and (7) and the movement of the holding and moving device (2) are explained below. They are fixed so that the directions (13) are perpendicular to each other. The end faces of these fibers (4) and (7) on the side of the holding and moving device (2) are all set to face the surface (11) of the semiconductor resin encapsulation molded product (1) with a certain distance apart. There is. The other end of the optical fiber (4) is a light source (5) that emits constant light.
), and furthermore, the other end face of the optical fiber (7) is provided with a light receiving element (8) such as a phototransistor or a fumetodiode. One optical fiber (
4) and one optical fiber (7) form a pair at a certain angle Q (for example, 60 degrees) with respect to the perpendicular to the surface (11) of the semiconductor resin encapsulation molded product (1). The optical fiber branch (3) is provided with a plurality of pairs of optical fibers (4) and (7). Light emitting part (6) and receiver = along with optical fibers (4) and (7)
4- The above-mentioned fibers (4) and (7) forming the base part (9) have a sufficient length so as not to hinder the movement of the measurement part (12). Each light receiving element (8) has an amplifier (
It is electrically connected to the multiplexer (15) via the multiplexer (14), and furthermore, on the output side of the multiplexer (15), there is a binarization circuit (16) in which a threshold value for distinguishing between bright and dark is set.
) is provided on the output side of this binarization circuit (16),
For example, an arithmetic control unit (17) such as a microcomputer
) are connected. This arithmetic control unit (17) includes a driver (19) for the automatic sorting device and a display unit (1B) for displaying test results such as a CRT or printer.
) are connected.

Next, the operation of the appearance surface inspection apparatus for semiconductor resin-sealed molded products of this embodiment will be explained.

First, the semiconductor resin molded product (1) is held and moved by the holding and moving device t/
(2) and the optical fiber (4) from the light source (5)
A constant 0 light of C is irradiated onto the semiconductor resin-sealed molded product (1) through the. The light reflected by the semiconductor resin molded product (1) passes through the optical fiber (7) to the light receiver (8).
), is amplified by the amplifier (14), input to the multiplexer (15), and sequentially output to the binarization circuit (16). In the binarization circuit (16), if the voltage of the signal is lower than the preset 1 value (when the molded product surface (11) is dirty and the amount of reflected light is small), the level is "1".
If the voltage of the signal is small (when the surface of the molded product (11) is clean and the amount of reflected light is large), the signal is at level "0", and the reference data is stored in advance in the arithmetic control section (17).
The data input from the binarization circuit (16) and the stored data are successively compared, and if both data match, it is judged as "good".
If there is a mismatch, it is judged as "defective" and the sorting device (19) is activated to reject the defective products, and the progress and results are displayed on the display section (18).

〔Effect of the invention〕

The present invention calculates the degree of dirt on the appearance surface of a semiconductor resin molded product based on the amount of light reflection, and automatically determines whether the molded product is good or not.
This is a method to screen out defects, whereas the conventional visual inspection was inefficient and inaccurate.
According to the method of the present invention, it has become possible to sort efficiently and accurately.

[Brief explanation of the drawing]

FIG. 1 shows a semiconductor resin 115 JJS according to an embodiment of the present invention.
An explanatory diagram showing the main parts of the appearance and surface inspection equipment for E-type products. Figure 2 is a plan view of the optical fiber (- support part), and Figure 3 is an air circuit system diagram of the appearance and surface inspection equipment. Semiconductor resin encapsulation molded product (2) Holding and moving device (3) Optical fiber support section (4) Optical fiber (for irradiation) (5) Light source (7) Optical fiber (for light reception) (8) Light receiver (14) Amplifying device (15) Multiplexer (16) Binarization circuit (17) Arithmetic control unit (18) Display unit (19) Sorting device

Claims (1)

[Claims] A method for inspecting the appearance and surface of a semiconductor resin-sealed molded product, characterized by evaluating the appearance and surface condition of the semiconductor resin-sealed molded product based on the amount of light reflected.