JPH0661604A - Printed wiring board - Google Patents

Abstract

PURPOSE:To facilitate test while preventing short circuit between a chip component and a board on a printed board where surface mounting of components is carried out through reflow soldering using cream solder or a printed wiring board where pads for connecting chip components are contrived. CONSTITUTION:The printed wiring board 1 comprises first and second pads 2 to be connected with the electrode parts of a chip component, a pattern 9 for each pad provided between the first and second pads, a test land 10 provided for the first pad and a corresponding pattern, and a test land 10 provided for the second pad and corresponding pattern, wherein predetermined conduction test is performed between the test lands.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed wiring board, and more particularly, it relates to a printed wiring board adapted to mount surface mount components by a reflow soldering operation using solder cream. Furthermore, the present invention relates to a printed wiring board in which a pad portion for connecting a minimold type component or a chip component is devised. Then, a short circuit between the chip component and the substrate can be prevented and the inspection can be easily performed.

[0002]

2. Description of the Related Art In this type of conventional technology, an adhesive is applied between pads to prevent a short circuit, or a groove is provided between pads to prevent a short circuit. 62-24998) is known. FIG. 7 is an illustration of a conventional device of this type. 7 (A) is a side sectional view, and FIG. 7 (B) or a plan view. In FIG. 7, a pad 2 is provided at an appropriate position on the printed wiring board 1, and an electrode 6 of a chip component 5 is bonded onto the pad 2 with a solder 4. Further, a resist 3 is provided on the portion excluding the pad 2. In this way, when the chip component 5 is provided, it is common to apply or print the cream solder 4A in the proper place,
When the applied / printed amount is excessive, after the reflow soldering process which is the final fixing process, the excess cream solder remains between the chip component 5 and the printed wiring board 1 to cause a short circuit. May cause. FIG. 8 is a diagram showing another conventional example of this type of technology. Incidentally, FIG. 8 is exemplified in the above-mentioned Japanese Utility Model Application No. 62-24998. In FIG. 8, the component 5
One lead 6 is provided at the center of the upper part of the above, and one lead 6 is provided at each of two left and right parts below that. Then, the component 5 is fixed by using a substantially T-shaped insulating adhesive 7 so that the leads 6 are separated from the solder. In such a case, it is necessary to fix the above-mentioned insulating adhesive to an appropriate place and then apply the conductive material, which deteriorates the work efficiency. FIG. 9 is a diagram showing another conventional example of this type of technology. This FIG. 9 is also exemplified in the above-mentioned Japanese Utility Model Application No. 62-24998. In FIG. 9, the component 5 is soldered through the pad 2 and the lead 5A provided at appropriate places on the printed wiring board 1.
It is mounted and fixed by. A required number of grooves 8 are provided in the portion of the printed wiring board 1 immediately below the component 5 so that the excess amount of the solder 4 escapes into the grooves 8. However, in this case, since the groove is provided between the pads, a solder ball (solder mass) is likely to be generated when the molten solder flows along the groove, and the solder escapes along the groove. That effect will be halved. Thus, even if various measures are taken to prevent short circuits, it is not possible to prevent short circuits completely. Further, it is impossible to detect a short circuit between the chip and the board by a visual inspection when the chip parts are attached, and even if an electrical inspection is performed, the conventional pad of this type can handle it. I can't.

[0003]

As described above, in the prior art, it is not possible to prevent a complete short circuit, and when a chip component is attached, the occurrence of a short circuit with the substrate is visually observed. It is impossible to find out by inspection, and there is a problem that even if an electrical inspection is performed, it is not possible to deal with this type of conventional pad.

The present invention has been made to solve the above-mentioned problems, and in a printed wiring board in which surface mounting components are mounted by a reflow soldering operation using a solder cream, a chip component is used. It is an object of the present invention to provide a device which can surely prevent a short circuit between a substrate and a substrate and can easily perform the inspection.

[0005]

A printed wiring board according to the present invention is provided with first and second pads connected to an electrode portion of a chip component; each pad provided between the first and second pads. Between the test lands; and a test land provided on the first pad and a pattern corresponding to the first pad; and a test land provided on the second pad and a pattern corresponding to the second pad. Then, a predetermined electrification test is carried out.

[0006]

In the printed wiring board according to the present invention, the first and second pads connected to the electrode portion of the chip component; the pattern for each pad provided between the first and second pads; the first pad Pad and a test land provided in a pattern corresponding thereto; and a test land provided in the second pad and a pattern corresponding to the pad, and a predetermined conduction test is performed between the test lands. Done;
It is characterized by that. Further, because of being configured with such characteristics, for example, in a printed wiring board in which surface mounting components are mounted by a reflow soldering operation using a solder cream, between the chip components and the substrate. The short circuit can be surely prevented and the inspection can be easily performed.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic explanatory view of an embodiment of a printed wiring board according to the present invention. First, FIG. 1 (A)
In the above, a pair of pads 2 for mounting required chip parts (not shown) are provided on a top surface of the printed wiring board 1 having a required thickness and made of a required material at a predetermined distance. The patterns 9 are arranged so as to face each other, and a pattern 9 having a predetermined shape is provided between the pair of pads 2. Then, these pads and patterns are provided with respective test lands 10. The pads and patterns here are created by etching a copper clad laminate. It should be noted that these test lands are arranged in a state where a desired test can be easily performed on the pads and patterns that are related to each other. In the next FIG. 1B, the above-mentioned FIG.
A side sectional view taken along the dotted line BB in (A) of FIG. It is considered that further detailed description of (B) in FIG. 1 is unnecessary, and therefore further description is omitted.
In FIG. 1C that follows this, a state is shown in which the resist 3 is applied to portions other than the pads 2, patterns 9 and test lands 10. Then, in FIG. 1D, a side sectional view taken along the dotted line DD in FIG. 1C is shown. In FIG. 1C, the solder plating 11 is formed on the pad 2. Also,
Pattern 9 remains copper.

FIG. 2 is a schematic explanatory view of another embodiment of the printed wiring board according to the present invention. First, in FIG. 2A, a pair of pads 2 for mounting a required chip component (not shown) on a top surface of a printed wiring board 1 having a required thickness and made of a required material,
The pads 9 are arranged so as to face each other with a predetermined distance, and a pattern 9 having a predetermined shape is provided between the pair of pads 2. Then, these pads and patterns are provided with respective test lands 10. The pads and patterns here are created by etching a copper clad laminate. It should be noted that these test lands are arranged in a state where a desired test can be easily performed on pads and patterns that are related to each other, and related ones are connected to each other by the connection portion 10A. Although the shape thereof is substantially rectangular unlike the case of FIG. 1A, any arbitrary shape can be selected as desired. In FIG. 2B, which is shown in FIG.
A side sectional view taken along the dotted line BB in (A) of FIG. It is considered that further detailed description of (B) in FIG. 2 is unnecessary, and therefore further description is omitted.
In FIG. 2C that follows this, the connection portion 10 of the test land 10 that connects the related pad 2 and the pattern 9 is connected.
A is cut 10B and electrically insulated from each other. Note that here, the state where the resist is not applied is shown. Then, in FIG. 2D, a side sectional view taken along the dotted line DD in FIG. 2C is shown. In FIG. 2D, solder plating 11 is formed on the pads 2 and the patterns 9. In this case, since the pattern 9 is subjected to the solder plating as described above, the melted cream solder easily flows on the pattern. Therefore, the cutting 10B in FIG. You have to be careful about the timing. The solder plating here can be replaced with gold plating.

FIG. 3 is a schematic explanatory view of an embodiment of a printed wiring board according to the present invention. First, in FIG. 3A, a pair of pads 2 for mounting a required chip component (not shown) on a top surface of a printed wiring board 1 having a required thickness and made of a required material,
The pads 9 are arranged so as to face each other with a predetermined distance, and a pattern 9 having a predetermined shape is provided between the pair of pads 2. Further, a suitable number of grooves 8 (a total of three grooves in FIG. 3) are provided between the pad and the pattern. Then, these pads and patterns are provided with respective test lands 10. The pattern here may be copper as it is, or may be plated with solder or gold.
It should be noted that these test lands are arranged in a state where a desired test can be easily performed on the pads and patterns that are related to each other. The formation of the groove 8 in this case can be suitably performed by using a spot facing process, a laser process, or the like. Next, in FIG. 3B, a side sectional view taken along the dotted line BB in FIG. 3A is shown. It is considered that further detailed description of (B) in FIG. 3 is unnecessary, so further description will be omitted. By providing the groove in this way, excess solder flows into the groove, and the effect of preventing a short circuit is further enhanced.

FIG. 4 is a schematic explanatory view of an embodiment of the printed wiring board according to the present invention. First, in FIG. 4A, a pair of pads 2 for mounting a required chip component (not shown) on the upper surface of a printed wiring board 1 having a required thickness and made of a required material,
The pads 9 are arranged so as to face each other with a predetermined distance, and a pattern 9 having a predetermined shape is provided between the pair of pads 2. The cutout portion 9A is provided so that the outer periphery of the pattern 9 is left. Various aspects of the cutout portion 9A will be described later. Then, these pads and patterns are provided with respective test lands 10. It should be noted that these test lands are arranged in a state where a desired test can be easily performed on the pads and patterns that are related to each other. Next, in (B1) of FIG. 4, (A) of FIG.
A side sectional view taken along the dotted line B1-B1 in FIG.
In (B1) of FIG. 4, the notch 9A for the pattern 9 is left at the outer periphery of the pattern 9 and its depth is made equal to the depth of the pattern 9 itself. In (B2) of FIG. 4 following this, a side sectional view taken along a dotted line B2-B2 in (A) of FIG. 4 is shown. In FIG. 4B2, the cutout portion 9 for the pattern 9 is formed.
A has a groove 8 in which the outer periphery of the pattern 9 is left and the depth thereof exceeds the depth of the pattern 9 itself. Then, in (B3) of FIG. 4, a side sectional view taken along a dotted line B3-B3 in (A) of FIG. 4 is shown. In FIG. 4B3, the notch 9A for the pattern 9 is formed as a groove 8 in which the outer periphery of the pattern 9 is left and the depth thereof exceeds the depth of the pattern 9 itself. , The pattern 9 and the groove 8 (the groove 8 is copper-plated in advance) are solder-plated 11 (more specifically, shown in FIG. 4C). .

FIG. 5 is a schematic explanatory view of an embodiment of a printed wiring board according to the present invention. First, in FIG. 5A, a pattern 91 between pads, which will be described later, is formed by etching on the upper surface of the inner layer substrate 1A having a required thickness and made of a required material. Then, if necessary, a copper plating 92 is applied on the copper plating 92 to adjust the thickness. In FIG. 5B, the pattern 91
The inner layer substrate 1A on which is formed is used as the lowermost layer, and the prepreg 1B and the outer layer substrate 1C are stacked in this order and heated appropriately.
The above three members are pressed together by pressurization. This is followed by FIG.
5C, a portion such as the pad 2 is provided at a proper position on the outer layer substrate 1C (specifically, the dotted line D1-D in FIG. 5C).
A blind through hole 92 is formed so as to pass through the inner layer pattern 91 together with the side cut portion of one portion (see (D1) in FIG. 5) (specifically, the dotted line D in FIG. 5 (C)).
2- (D2) of FIG. 5, which is a side cut portion of the D2 site). Then, as shown in FIG. 5E or FIG. 5F, the outer layer substrate 1 is formed on the inner layer pattern 91.
The groove 8 is formed from the C side by the above-described counterboring or laser processing so that the inner layer pattern 91 is exposed.

FIGS. 6A and 6B are exemplary views when the printed wiring board of the above-described embodiment is tested. FIG. 6A is an exemplary view of a test mode, and FIG. 6B is an exemplary test result. It is a figure. First, in FIG. 6A, the printed wiring board 1
A desired pair of test lands 10 individually corresponding to the pads 2 and patterns 9 formed on the upper part of the probe, a pair of probes p from an appropriate measuring means (for example, tester M).
By contacting 1 and p2, the required energization test can be performed. FIG. 6B exemplifies the result of the energization test for some samples (here, two samples).

[0013]

As described above in detail, the printed wiring board according to the present invention is provided with the first and second pads connected to the electrode portion of the chip component; provided between the first and second pads. A pattern for each pad; a test land provided on the first pad and a pattern corresponding thereto; and a test land provided on the second pad and a pattern corresponding thereto; A predetermined energization test is performed between the test lands; Further, because of being configured with such characteristics, for example, in a printed wiring board in which mounting of surface mount components is performed by reflow soldering operation using solder cream, chip components and substrates are There is an effect that a short circuit between them can be surely prevented and the inspection can be easily performed.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of an embodiment of a printed wiring board according to the present invention.

FIG. 2 is a schematic explanatory view of another embodiment of the printed wiring board according to the present invention.

FIG. 3 is a schematic explanatory view of an embodiment of a printed wiring board according to the present invention.

FIG. 4 is a schematic explanatory view of an embodiment of a printed wiring board according to the present invention.

FIG. 5 is a schematic explanatory view of an embodiment of a printed wiring board according to the present invention.

FIG. 6 is an exemplary diagram when a test of the printed wiring board of the above-described embodiment is performed.

FIG. 7 is an illustration of a conventional device of this type.

FIG. 8 is a diagram showing another conventional example of this type of technology.

FIG. 9 is a diagram showing another conventional example of this type of technology.

[Explanation of symbols]

 1: Printed wiring board; 2: Pad; 3: Resist; 9: Pattern; 10: Test land; 11: Solder plating;

Claims (1)

[Claims] 1. A first and a second connecting to an electrode part of a chip component.
Pad; a pattern for each pad provided between the first and second pads; a test land provided on the first pad and a pattern corresponding thereto; and the second pad and this A printed wiring board comprising: test lands provided in a pattern corresponding to: a predetermined electrification test is performed between the test lands;
A printed wiring board characterized by the above.