CN101277584A

CN101277584A - Circuit board

Info

Publication number: CN101277584A
Application number: CNA2007102003324A
Authority: CN
Inventors: 吴鹤鸣; 曾富岩; 陈建荣
Original assignee: Hongfujin Precision Industry Shenzhen Co Ltd; Hon Hai Precision Industry Co Ltd
Current assignee: Hongfujin Precision Industry Shenzhen Co Ltd; Hon Hai Precision Industry Co Ltd
Priority date: 2007-03-27
Filing date: 2007-03-27
Publication date: 2008-10-01

Abstract

The present invention provides a circuit board, including a substrate, a pad array used for adhesive packing electronic elements and insulation filler filling between pads. The pad array is provided on the surface of the substrate. The insulation filler is used for isolating and fixing the pad. The pad array includes a plurality of first pads, and a plurality of second pads. The plurality of second pads is symmetrically distributed on the periphery of the pad array. The area of the second pad is larger than the area of the first pad. When electronic elements are assembled, since the area of the second pad is larger than the area of the first pad, the offset between electronic element and the pad is greatly reduced, avoiding the impact to the product quality caused by the skew offset between electronic element and the pad, and bad contact caused by false welding etc.

Description

Circuit board

Technical field

The present invention is about a kind of circuit board, especially about a kind of circuit board that is provided with pad.

Background technology

Along with the continuous development of science and technology, portable electronic equipment such as mobile phone are used increasingly extensively, also day by day trend towards simultaneously light and handy, attractive in appearance and multifunction, and wherein camera function is the additional function of popular in recent years mobile phone.The numerical camera mould that is applied to mobile phone not only will satisfy compact requirement, and it also must have higher photographic property.And the quality of digital camera lens modular circuit plate is one of principal element of decision photographic property, in the digital camera lens module, the pad of using on the circuit board connects various electronic devices and components, and therefore, the pad that improves circuit board will help improving its product yield.

Be illustrated in figure 1 as the floor map of the pad size of custom circuit plate, this circuit board comprises a substrate 1, the pad 2 of a plurality of electrical connection electronic components, and the area of its pad is all identical.

When Fig. 2 is BGA Package sometimes the position of soldered ball and pad the schematic diagram of dislocation takes place.As shown in Figure 2, solid line is a pad 2, and dotted line is the position of soldered ball 3 after the BGA Package.As can be seen from Figure 2, because machinery and artificial accumulated error, and the cohesiveness unanimity of pad, skew has taken place in the soldered ball position after the feasible encapsulation and the position of pad, and far away more from the circuit board center, and side-play amount is big more.Crooked skew between electronic devices and components and the pad can influence the quality of camera, even can cause loose contacts such as rosin joint.

Summary of the invention

In view of this, be necessary to provide the circuit board of the crooked side-play amount of a kind of effective reduction electronic component.

A kind of circuit board comprises a substrate, is used to mount the pad array of electronic devices and components and is filled in insulation filler between the pad.Described pad array is arranged on the surface of substrate.Described insulation filler is used for isolating and anchor pad.Comprise a plurality of first pads and a plurality of second pad in the described pad array.Described a plurality of second pad is symmetrically distributed in this pad array periphery.The area of described second pad is bigger than the area of first pad.

Compared with prior art, when described circuit board utilizes surface mounting technology to assemble electronic devices and components, under the situation that has mechanical and artificial accumulated error, because second bonding pad area is bigger than the area of first pad, so this second pad is also big than first pad to the cohesiveness of scolding tin, therefore, because under the interaction force that cohesiveness produced of a plurality of second pads that are symmetrically distributed in the pad array periphery, make the arbitrary pad in the pad array and the relative position of scolding tin obtain revising, thereby reduce the side-play amount of arbitrary pad in scolding tin and the pad array.By the side-play amount of reduction scolding tin and pad, thereby make the welding position of electronic component and pad more accurate.

Description of drawings

Fig. 1 is the floor map of the pad size of available circuit plate;

Fig. 2 is that the position of soldered ball and pad concerns schematic diagram when carrying out grid array package for the available circuit plate;

Fig. 3 is the floor map of pad array of the circuit board of first embodiment of the invention;

Fig. 4 is the cutaway view of the circuit board of Fig. 3 along the II-II line;

Fig. 5 A to 5E is the board pads forming process of making first embodiment;

Fig. 6 is the floor map of pad array of the circuit board of second embodiment of the invention.

Embodiment

For the present invention being done further explanation, lift following preferred embodiment and conjunction with figs. and be described in detail as follows.

See also Fig. 3 and Fig. 4, the circuit board 10 of first embodiment of the invention comprises a substrate 11, be used to mount that the pad array 12 of electronic devices and components (diagram is shown) and one deck are used to isolate and the filler 15 of fixing described pad array 12.

Described circuit board 10 can be track circuit board (Printed Circuit Board is called for short pcb board).This circuit board can will have the electronic devices and components of specific function, all is set on this pcb board 10.And except fixing various little electronic devices and components, pcb board 10 also is used to above-mentioned electronic devices and components that mutual electrical connection is provided.This circuit board 10 can be used in the image sensing module (figure does not show) of digital camera.

This substrate 11 is an insulating barrier, and its material can be served as reasons, and insulation is heat insulation, also unbending material is made, and this material can be plastics, pottery etc.Material at substrate described in the first embodiment of the invention 11 is plastics, and this plastic material adopts unsaturated polyester resin or glass laminate.

Arbitrary pad in the described pad array 12 can be square, rectangle, octangle, circle, ellipse.Be circular in the present embodiment.Certainly according to the difference of the electronic devices and components that mounted, can be other different shape with the pad design of this pad array 12.

The arrangement mode of this pad array 12 can be rectangular array arrangement mode or annular array arrangement method, is the rectangular array arrangement mode in first embodiment.

Described pad array 12 comprises a plurality of second pads 121 and a plurality of first pad 122.Described a plurality of second pad is symmetrically distributed in the periphery of pad array 12, and the diameter of described second pad 121 is bigger than the diameter of first pad 122.Because the diameter of described second pad 121 is bigger than the diameter of first pad 122, so the area of second pad 121 is bigger than the area of first pad 122.

This second pad 121 is provided with four in first embodiment, be symmetrically distributed in respectively on four drift angles of rectangular array, be used for when giving the circuit board print solder when (figure does not show), revise the relative position of all pads in scolding tin and the pad array 12, thereby reduce the side-play amount of arbitrary pad in scolding tin and the pad array 12.

This second pad 121 is compared with the area of first pad 122, and its area is set according to needs by the rootlet that differs greatly.For example, second pad 121 and first pad, 122 area occupied arrange that with not overslaugh circuitous pattern (figure does not show) is as the criterion

See also Fig. 5 A to 5E, it has described the pad 12 and forming method thereof of the pcb board 10 of present embodiment.

Step 1: shown in Fig. 5 A, form metal forming 123 by printing machine (figure does not show) printing on substrate 11.Preferably, this metal forming 123 is a copper-clad paper tinsel laminate.

Step 2: shown in Fig. 5 B, the metal forming 123 that is formed on the substrate 11 is etched to form and as shown in Figure 3 the consistent metallic pattern 124 of pad array 12 arrangement modes by etch process, this metallic pattern 124 comprise with the big metallic pattern 1241 of second pad, 121 corresponding settings and with the little metallic pattern 1242 of first pad, 122 corresponding settings, form circuitous pattern simultaneously.The area of described big metallic pattern 1242 is greater than the area of little metallic pattern 1241.

Step 3: as Fig. 5 C, filler 15 is filled between the metallic pattern 124, and the same high with metallic pattern 124.For filler 15, it is an insulating material, and preferably uses the printing ink or the solder resist of infrared curing, especially photoresistance solder flux.This filler 15 can be by directly filling with squeegee (figure does not show).

After having filled filler 15, with metallic pattern 124 with respect to the upper surface 124a of substrate 11 and the surface cleaning of filler 15.Certainly, can also carry out smooth surface or give suitable illumination process this pcb board as required.

Step 4: shown in Fig. 5 D, be the structural representation behind metallic pattern 124 electronickellings or the gold.When carrying out nickel plating or gold plating, the nickel molecule of electroplating solution at first is plated on the metallic pattern 124, makes to form nickel coating 125 on the upper surface 124a that metallic pattern 124 exposes.At this moment, because filler 15 is insulating material, on the surface of filler 15, will can not form nickel coating 125.

Step 5: shown in Fig. 5 E, after nickel coating 125 is plated in the upper surface 124a that metallic pattern 124 exposes, will be at the surperficial plated with gold coating 126 of nickel coating 125, thus finish the making of pad 12.In addition, because filler 15 has covered the side of metallic pattern 124, and only exposed the upper surface 124a of metallic pattern 124, nickel coating 125 will only form at the upper surface 124a of metallic pattern 124, and gold plate 126 will be formed on the nickel coating 125 whole exposed surfaces.

So, just finish the making of the pad array 12 of circuit board 10, shown in Fig. 3, the area of second pad, 121 to the first pads 122 that four of the pad array of being finished by above-mentioned processing procedure made 12 are distributed in four drift angles of rectangular array is big.

See also Fig. 6, be the floor map of the pad array of the circuit board of second embodiment of the invention.Described circuit board 20 comprises a substrate 21 and a pad array 22.The pad array 22 of second embodiment is compared with the pad array 12 of first embodiment, and its difference is the arrangement mode difference of pad array 22, and the arrangement mode of the pad array 22 of second embodiment is the annular array arrangement mode.

Described pad array 22 comprises even number be centrosymmetric second pad 221 and a plurality of first pad 222 of the periphery that is distributed in pad array 22.Described in a second embodiment pad array 22 has four described second pads 221, and the area of described second pad 221 is bigger than the area of first pad 222.Certainly also be not limited to four, optionally set.

Because the area of second pad 121,221 of

pad array

12 and 22 is bigger than the area of first pad 122,222, so the cohesiveness of 121,221 pairs of scolding tin of this second pad is big than first pad 122,222 also, therefore, because under the interaction force that cohesiveness produced of a plurality of second pads 121,221 that are symmetrically distributed in the pad array periphery, make the arbitrary pad in

pad array

12 and 22 and the relative position of scolding tin obtain revising, thereby reduce the side-play amount of arbitrary pad in scolding tin and the pad array 12.By the side-play amount of reduction scolding tin and pad, thereby make the welding position of electronic component and pad more accurate.

In addition, those skilled in the art also can do other variation in spirit of the present invention, as long as it does not depart from technique effect of the present invention, all should be included within the present invention's scope required for protection.

Claims

1. circuit board, comprise a substrate, be used to mount the pad array of electronic devices and components and be filled in insulation filler between the pad, described pad array is arranged on the surface of substrate, described insulation filler is used for isolating and anchor pad, it is characterized in that: comprise a plurality of first pads and a plurality of second pad in the described pad array, described a plurality of second pad is symmetrically distributed in this pad array periphery, and the area of described second pad is bigger than the area of first pad.

2. circuit board as claimed in claim 1 is characterized in that: arbitrary pad is divided into three layers in the described pad array, and internal layer is a copper, and skin is a gold, and the intermediate layer is a nickel.

3. circuit board as claimed in claim 1 is characterized in that: described baseplate material is plastics, and this plastic material adopts unsaturated polyester resin or glass laminate.

4. circuit board as claimed in claim 1 is characterized in that: described filler is an insulating material.

5. circuit board as claimed in claim 4 is characterized in that: described filler is the printing ink or the solder resist of infrared curing.

6. circuit board as claimed in claim 1 is characterized in that: described filler is the photoresistance solder flux.

7. circuit board as claimed in claim 1 is characterized in that: described circuit board is used for the image sensing module of digital camera.

8. circuit board as claimed in claim 1 is characterized in that: what described pad array arrangement mode can be in rectangular array and the annular array is a kind of.

9. circuit board as claimed in claim 8 is characterized in that: when described pad array was the rectangular array distribution, the array periphery had four described second pads, and these four second pads are distributed on four drift angles of rectangular array.

10. circuit board as claimed in claim 8 is characterized in that: described pad array is an annular array when distributing, and the array periphery has even number second pad, and the distribution that is centrosymmetric in pad array of this even number second pad.