TW201424498A - A circuit board - Google Patents

Abstract

A circuit board includes a substrate, a circuit, and a solder resist layer. The circuit is located on the substrate. The circuit includes a first test pad and a second test pad. There is a default separation between the first test pad and the second test pad. The solder resist layer is located on the circuit. The solder resist layer has two holes which expose the first test pad and the second test pad, respectively.

Description

Circuit board

The present invention relates to a circuit board, and more particularly to a circuit board having a high speed signal measuring contact.

Over the years, handheld electronic products (such as mobile phones or navigation devices) have been designed to be light and thin, making the internal parts of the product more and more dense, relatively in the process of manufacturing such electronic products ICT (In -Circuit Test) Testing is also becoming more and more important.

A printed circuit board (PCB) has test lines around the electronic components to perform high-speed signal measurement through test points on the test lines to analyze the characteristics of the circuit design by measuring the results. The traditional ICT test method is to design a single-point test pad from a circuit board trace to measure the high-speed signal, and then touch the test pad through the probe on the ICT device to perform circuit characteristic test of the electronic part. However, when the test is performed, the measured signal is easily affected by the test pad to generate noise, and the single-point test pad is also likely to cause an inaccurate phenomenon of high-speed signal measurement, thereby reducing the ICT test yield.

In view of the problems encountered in the prior art, the present invention discloses a circuit board with a circuit board having a first test pad and a second test pad to improve the accuracy of high-speed signal measurement, so as to test high-speed signals. The effect of the rate.

A circuit board according to an embodiment of the invention includes a substrate and a line Road, and a solder mask. The circuit is disposed on the substrate and the circuit includes a first test pad and a second test pad. The first test pad is spaced apart from the second test pad by a predetermined distance. The solder resist layer is disposed on the line and the solder resist layer has two openings, and the two openings respectively expose the first test pad and the second test pad.

Since the circuit board has the first test pad and the second test pad spaced apart from each other, the probe on the test fixture contacts the first test pad compared to the conventional single-point test pad. When the second test pad is used, the circuit board of the above embodiment can improve the accuracy of high-speed signal measurement.

The above description of the present invention and the following description of the embodiments of the present invention are intended to illustrate and explain the spirit and principles of the invention.

The detailed features and advantages of the present invention are set forth in the Detailed Description of the Detailed Description of the <RTIgt; </ RTI> <RTIgt; </ RTI> </ RTI> </ RTI> <RTIgt; The objects and advantages associated with the present invention can be readily understood by those skilled in the art. The following examples are intended to describe the present invention in further detail, but are not intended to limit the scope of the invention.

Referring to FIG. 1A, a circuit board 100 according to an embodiment of the present invention includes a substrate 101, a line 102, and a solder resist layer 103. The line 102 is disposed on the substrate 101 and the line 102 includes a first test pad 120 and a second test pad 140. The first test pad 120 is spaced apart from the second test pad 140 by a predetermined distance x, In some embodiments, x can be 10 mils.

Please refer to FIG. 1B for a side view of the circuit board 100 of FIG. 1A. As shown in FIG. 1B, the solder resist layer 103 covers the substrate 101 and the line 102, and has two openings 104. The first test pad 120 and the second test pad 140 are respectively exposed by the two openings 104 and 105. The two openings 104 and 105 of the solder resist layer 103 are used to define the first test pad 120 and the second test. The solder region of the pad 140, in other words, the solder mask layer 103 having the two openings 104, 105 prevents solder from overflowing to other areas of the circuit board 100.

In this embodiment, the shapes of the first test pad 120 and the second test pad 140 are semi-elliptical and the area of the first test pad 120 is equal to the area of the second test pad 140. In some embodiments, the shape of the first test pad 120 and the second test pad 140 may be elliptical or rectangular, but not limited thereto. In addition, the first test pad 120 is spaced apart from the second test pad 140 by a predetermined distance x, and in some embodiments, x may be 10 mils.

Please refer to FIG. 2, which shows a schematic diagram of the soldering of the circuit board 100 of FIG. 1A. The solder paste is applied to the circuit board 100 of FIG. 1A through the steel sheet, and then the solder balls 210 and 220 are respectively formed at the two openings of the solder resist layer 103 via the high-temperature solder furnace process. 104, 105 and the two solder balls 210 and 220 are electrically connected to the first test pad 120 and the second test pad 140 of FIG. 1A. In some embodiments, the material of the line 102 can be copper, but not limited thereto. The material is used to increase the adhesion with the solder ball. The opening diameter of the steel plate can be 4 mm to improve the contact area between the first test pad 120 and the second test pad 140 of "Fig. 1A" and the solder. The contact area between the tin.

On the other hand, the solder-implanted circuit board 100 can be used with the probe design on the test fixture to bring the tin balls 210, 220 and the probe into contact with each other to measure the high-speed signal. In some embodiments, the probe can be a flat or star needle, wherein the flat needle can have sixteen jaws and the needle diameter can be 35 mils, while the star can have eight sides and The needle diameter can also be 35 mils.

In order to improve the accuracy of the high-speed signal measurement, in some embodiments, the length y and the width z of the first test pad 120 and the second test pad 140 of FIG. 1A can be designed as the following combinations. The first set of lengths y may be 6.5 mils, the width z may be between 7.5 mils and 8 mils, the second set of lengths y may be 7.35 mils, and the width z may be between 6.5 mils to 7 mils, the third The group length y can be 8 mils, the width z can be between 5.5 mils to 6 mils, the fourth set length y can be 10 mils, the width z can be between 4.5 mils to 5 mils, and the fifth set length y can be 12 mils and width z can range from 3.5 mils to 4 mils.

The circuit board 100 having the first test pad 120 and the second test pad 140 as shown in FIG. 1A is loaded on a test fixture of a test machine, and is matched with a flat claw on the test fixture or The probe design of the star needle, the test method thus combined can be called MECA (micro-embedded component access). After the yield statistics of the test process, the circuit board 100 having the first test pad 120 and the second test pad 140 can improve the accuracy of the high-speed signal measurement.

In summary, since the circuit board of the embodiment has the first test pad and the second test pad spaced apart from each other, compared with the conventional single-point test pad, when When the probe on the test fixture contacts the first test pad and the second test pad, the circuit board of the above embodiment can improve the accuracy of the high-speed signal measurement.

Although the present invention has been disclosed above in the foregoing embodiments, it is not intended to limit the invention. It is within the scope of the invention to be modified and modified without departing from the spirit and scope of the invention. Please refer to the attached patent application for the scope of protection defined by the present invention.

100‧‧‧ boards

101‧‧‧Substrate

102‧‧‧ lines

103‧‧‧ solder mask

104, 105‧‧‧ two openings

120‧‧‧First test pad

140‧‧‧Second test pad

210, 220‧‧‧ two tin balls

x‧‧‧Preset distance

y‧‧‧First test pad length, second test pad length

z‧‧‧First test pad width, second test pad width

Figure 1A is a circuit board in accordance with an embodiment of the present invention.

Fig. 1B is a side view of the circuit board of Fig. 1A.

Fig. 2 is a schematic view showing the implantation of solder into the circuit board of Fig. 1A.

100‧‧‧ boards

101‧‧‧Substrate

102‧‧‧ lines

103‧‧‧ solder mask

120‧‧‧First test pad

140‧‧‧Second test pad

x‧‧‧Preset distance

y‧‧‧First test pad length, second test pad length

z‧‧‧First test pad width, second test pad width

Claims (6)

A circuit board includes: a substrate; a circuit disposed on the substrate, the circuit comprising a first test pad and a second test pad, the first test pad being spaced apart from the second test pad by a predetermined distance And a solder resist layer disposed on the circuit, the solder resist layer having two openings, the two openings respectively exposing the first test pad and the second test pad. The circuit board of claim 1, wherein the predetermined distance is 10 mils. The circuit board of claim 1, wherein the first test pad and the second test pad are semi-elliptical in shape. The circuit board of claim 1, wherein the first test pad and the second test pad are elliptical in shape. The circuit board of claim 1, wherein the first test pad and the second test pad are rectangular in shape. The circuit board of claim 1, wherein the circuit is made of copper.