JPH11330316A - Electronic parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain electronic parts against which not only the connectability of solder connections but also the mounting direction of the parts can be confirmed through the analysis of X-ray transmission pictures. SOLUTION: Electronic parts have a thick plate-like external member 11 which is made of a resin and packages a semiconductor chip, (n) pieces of L-shaped lead pins 121-12n which are protruded from both longer side faces of the member 11 and connected to the semiconductor chip through lead wires, and a heavy metal member 13 buried in a marker section 11a and has a high X-ray absorption factor. The member 13 is provided for confirming the position of the lead pin 121 having a pin number '1', namely, the mounting direction of the parts 10 by analyzing X-ray transmission pictures.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electronic component such as a semiconductor device.

[0002]

2. Description of the Related Art FIG. 3A is a perspective view showing the appearance of a conventional electronic component 1, and FIG. 3B is a plan view showing the appearance of the electronic component 1 shown in FIG. FIG. FIG.
The electronic component 1 shown in (a) is a so-called surface mount type electronic component (SM) that is connected by soldering to a printed wiring board (PWD: Printed Wiring Board) by a reflow method.
D: Surface Mounted Device). In FIG. 3A, reference numeral 2 denotes an exterior member for packaging a semiconductor chip (not shown), which is formed of a resin in a thick plate shape. From both long side surfaces of the exterior member 2, n lead pins 31 to 3n (see FIG. 3B) connected to the semiconductor chip via lead wires respectively project therefrom. These lead pins 31 to 3n are connected to terminals of the printed wiring board by soldering. In addition, lead pin 31
-3n are assigned pin numbers 1-n, respectively. The lead pins 3 on the surface of the exterior member 2
In the vicinity of 1 (pin number 1), a concave marker portion 2a is formed, and this marker portion 2a indicates the position of the lead pin 31 of pin number 1.

Here, in the electronic component 1 mounted on the printed wiring board by soldering, the mounting direction, the mounting position, the name of the mounted component, Confirmation of the connectivity etc. of the solder connection part is performed. Among these check items, an example of a method of checking the connectivity of the solder connection portion is to irradiate the electronic component 1 mounted on the printed wiring board with X-rays,
There is a method using a line transmission image. This method utilizes the property of X-rays, that is, a material having a higher specific gravity has a greater absorption of X-rays, and the same material has a greater absorption of X-rays as its thickness increases.

Further, in the above method, an X-ray transmission image obtained by irradiating the electronic component 1 mounted on the printed wiring board with X-rays is analyzed.
Check the connection status of the solder connection. Here, an example of the X-ray transmission image is shown in FIG. FIG. 4 is a diagram illustrating an X-ray transmission image when the electronic component 1 illustrated in FIG. 3B is irradiated with X-rays. In this figure, 4 is a lead frame. 5, 5,... Are the electronic components 1 (see FIG. 3B).
Are a plurality of solder connection portions. Here, the reason why the concentration of the solder connection parts 5, 5,.
Since the thickness of the solder connection portion 5 is thicker than other portions, X
This is because the line absorptivity is high. Therefore, the solder connection 5
Is checked by analyzing the density of the X-ray transmission image shown in FIG. Further, an automatic soldering inspection apparatus for surface-mounted electronic components using the above-described method has been widely used.

[0005]

By the way, in the conventional electronic component 1, although the connectivity of the solder connection portions 5, 5,... Can be confirmed by analyzing the X-ray transmission image, the X-ray The method of analyzing the transmission image has a drawback that when the internal structure of the electronic component 1 mounted on the printed wiring board is symmetric with respect to the longitudinal axis, the mounting direction cannot be confirmed. Therefore, in the conventional electronic component 1, in addition to the confirmation of the solder connectivity using the X-ray transmission image, the confirmation of the mounting direction has to be separately performed by another method. The present invention has been made under such a background, and provides an electronic component capable of confirming the mounting direction in addition to confirming the connectivity of a solder connection part by analyzing an X-ray transmission image. The purpose is to do.

[0006]

According to a first aspect of the present invention, there is provided an exterior member for packaging a semiconductor chip, and a plurality of leads electrically connected to the semiconductor chip and projecting from side surfaces of the exterior member. A pin, and a metal member that is provided at a predetermined position of the exterior member and that absorbs X-rays and that indicates a mounting direction when the plurality of lead pins are mounted on a substrate is provided. According to a second aspect of the present invention, in the electronic component according to the first aspect, a pin number is assigned to the plurality of lead pins, and the metal member has a predetermined pin number in the exterior member. It is characterized in that it is provided in the vicinity position. According to a third aspect of the present invention, in the electronic component according to the first or second aspect, the metal member is embedded in the exterior member. According to a fourth aspect of the present invention, in the electronic component according to the first or second aspect, the metal member is incorporated in the exterior member. According to a fifth aspect of the present invention, in the electronic component according to the first or second aspect, the metal member is coated at a predetermined position on a surface of the exterior member.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a perspective view illustrating an external configuration of an electronic component 10 according to an embodiment of the present invention, and FIG. 1B is a plan view illustrating an external configuration of the electronic component 10 illustrated in FIG. It is. In FIG. 1A, an electronic component 10 is, for example, an SOP (Small Outline Packag).
e) type. Reference numeral 11 denotes an exterior member for packaging a semiconductor chip (not shown), which is formed of a resin in a thick plate shape. From both long side surfaces of the exterior member 11, n generally approximately L-shaped lead pins 121 to 12n (see FIG. 1B) protruding from the semiconductor chip via lead wires project therefrom.

The lead pins 121 to 12n are connected to terminals of the printed wiring board by soldering.
The lead pins 121 to 12n have pin numbers 1 to 12, respectively.
Numbers up to n are given. A concave marker portion 11a is formed near the lead pin 121 (pin number 1) on the surface of the exterior member 11, and the marker portion 11a indicates the position of the lead pin 121 of pin number 1.

Reference numeral 13 denotes a heavy metal member buried in the marker portion 11a, which has a property of high X-ray absorption. In other words, the heavy metal member 13 is for confirming the position of the lead pin 121 of the pin number 1, that is, the mounting direction of the electronic component 10 by an X-ray transmission image.

In the above configuration, X (not shown) is attached to the electronic component 10 mounted on the printed wiring board by soldering.
When X-rays are emitted from the X-ray apparatus, an X-ray transmission image shown in FIG. 2 is obtained. In this figure, 14 is a lead frame. Are electronic components 10 (FIG. 1).
(Refer to (b))). Here, the reason why the concentration of the solder connection portions 15, 15,... Is particularly higher than that of the other regions is that the thickness of the solder connection portions 15 is thicker than other portions, so that the X-ray absorption rate is high. Because. Therefore, the confirmation of the connectivity of the solder connection portion 15 is performed by using the X shown in FIG.
This is performed by analyzing the density of the line transmission image.

Reference numeral 16 denotes a heavy metal member 13 (FIG. 1).
(See (b))), and the X-rays are absorbed at a high rate, so that the density is particularly high compared to other regions. That is, the X-ray transmission image shown in FIG. 2 is an image that is asymmetric with respect to the axis in the longitudinal direction because the heavy metal portion 16 is displayed in black.

Therefore, in the inspection process of the electronic component 10 according to the above-described embodiment, even if the internal structure of the electronic component 10 is symmetrical with respect to the longitudinal axis, X shown in FIG.
Since the X-ray transmission image is asymmetric, the mounting direction of the electronic component 10 mounted on the printed wiring board can be checked by checking the position of the heavy metal portion 16 in this X-ray transmission image.

As described above, according to the electronic component 10 according to the above-described embodiment, since the heavy metal member 13 is embedded in the marker portion 11a, the mounting direction of the electronic component 10 mounted on the printed wiring board is reduced. Can also be determined by an X-ray device. Therefore, according to the electronic component 10 according to the above-described embodiment, the electronic component 1 is conventionally used in an X-ray apparatus that has been used only for checking the connectivity of the solder connection portion 15.
The mounting direction of 0 can also be inspected.

Thus, according to the electronic component 10 according to the above-described embodiment, human visual observation is performed to avoid component destruction or circuit malfunction due to reverse mounting of the polarity or direction of the electronic component 10. , And the connectivity of the solder connection portion 15 can be automatically performed only by the X-ray apparatus.

Although the electronic component 10 according to one embodiment of the present invention has been described in detail above, the specific configuration is not limited to this embodiment, and a design change or the like may be made without departing from the gist of the present invention. The present invention is also included in the present invention. For example,
In the electronic component 10 according to the above-described embodiment, the example in which the heavy metal part 16 is embedded in the marker part 11a has been described. However, the present invention is not limited to this example.
May be coated with heavy metal, or the heavy metal portion 16 may be built in the exterior member 11.

Further, in the electronic component 10 according to the above-described embodiment, the example in which the heavy metal member 13 is embedded near the lead pin 121 of the pin number 1 has been described, but the present invention is not limited to this. The embedding position of the heavy metal member 13 may be any position as long as the mounting direction can be confirmed by the X-ray transmission image. In short, in this case, the heavy metal member 13 may be provided at a position where the X-ray transmission image becomes asymmetric.

[0017]

As described above, according to the present invention,
In an X-ray transmission image obtained when X-rays are radiated while being mounted on a board by soldering, in addition to the area corresponding to the solder connection part, the area corresponding to the metal member is compared to other areas. Darkens. Therefore, according to the present invention, X
By analyzing the line transmission image, it is possible to obtain the effect that the mounting direction can be checked in addition to the checking of the connectivity of the solder connection portion.

[Brief description of the drawings]

FIG. 1 is a diagram showing an external configuration of an electronic component 10 according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an X-ray transmission image obtained when the electronic component 10 illustrated in FIG. 1B mounted on a printed wiring board is irradiated with X-rays.

FIG. 3 is a diagram showing an external configuration of a conventional electronic component 1.

4 is a diagram showing an X-ray transmission image obtained when the electronic component 1 shown in FIG. 3B mounted on a printed wiring board is irradiated with X-rays.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Electronic component 11 Exterior member 11a Marker part 121-12n Lead pin 15 Solder connection part 13 Heavy metal member 16 Heavy metal part

Claims (5)

[Claims] An exterior member for packaging a semiconductor chip; a plurality of lead pins electrically connected to the semiconductor chip and protruding from a side surface of the exterior member; and a case where the plurality of lead pins are mounted on a substrate. An electronic component, comprising: a metal member provided at a predetermined position on the exterior member, the metal member absorbing X-rays, the mounting member indicating the mounting direction of the electronic component. 2. The plurality of lead pins are provided with pin numbers, and the metal member is provided at a position near a predetermined pin number on the exterior member.
Electronic components according to the above. 3. The electronic component according to claim 1, wherein the metal member is embedded in the exterior member. 4. The electronic component according to claim 1, wherein the metal member is built in the exterior member. 5. The electronic component according to claim 1, wherein the metal member is coated at a predetermined position on a surface of the exterior member.