CN201893778U

CN201893778U - Wireless module based on LCC (leadless chip carrier) package

Info

Publication number: CN201893778U
Application number: CN2010202251035U
Authority: CN
Inventors: 林代娟; 吴文伟
Original assignee: Leadcore Technology Co Ltd
Current assignee: Leadcore Technology Co Ltd
Priority date: 2010-06-11
Filing date: 2010-06-11
Publication date: 2011-07-06
Anticipated expiration: 2020-06-11

Abstract

The utility relates to a wireless module based on an LCC (leadless chip carrier) package, which is made of a plurality of layers of printed circuit boards. The wireless module comprises a radio frequency testing pad for testing and an antenna aperture pad used during application, wherein the radio frequency testing pad is arranged at the bottom layer of the plurality of layers of printed circuit boards, the antenna aperture pad goes through from the top layer of the plurality of layers of printed circuit boards to the bottom layer, and then the antenna aperture pad is coincided with the radio frequency testing pad at the bottom layer. Therefore, the radio frequency index of the wireless module in practical application is substantially equal to the radio frequency index of the wireless module in testing, so that the problem of inconsistent radio frequency indexes between practical application and testing is eliminated.

Description

Wireless module based on the LCC encapsulation

Technical field

The utility model relates to a kind of wireless package module, especially relates to a kind of wireless module based on the LCC encapsulation.

Background technology

In 2G, 3G and the WiFi wireless module, use a kind of packaged type that is called leaderless chip carrier carrier (LCC), board to board connector and antenna connector are saved in the LCC encapsulation, and each road signal that directly will be connected with outside motherboard is distributed in (comprising radiofrequency signal, radio frequency ground etc.) both sides, three limits of wireless module or all around, make the mode of stamp hole pin pad, make the as a whole SMT Surface Mount that passes through to motherboard, reach communicating to connect of wireless module and motherboard.

The wireless module of this LCC encapsulation, for calibration and the test that realizes radio-frequency (RF) index, common way is to do a radio frequency testing branch road, i.e. RF testing weld pad at the radio-frequency antenna mouth.Fig. 1 illustrates the circuit theory diagrams of radio-frequency antenna mouth.

Shown in Fig. 2 A-2C, wherein Fig. 2 A illustrates printed circuit board (PCB) (PCB) top layer layout separately, and Fig. 2 B illustrates printed circuit board (PCB) bottom layout separately, and Fig. 2 C illustrates top layer and bottom layout stacking chart.In Fig. 2 A-2C, element L1, L2 are corresponding with L1, L2 and the C1 of same numeral among Fig. 1 with C1.On printed circuit board (PCB) was realized, after the RF IN/OUT process inductance L 2 and capacitor C 1 of present normally top layer, punching (laser hole+blind buried via hole) cabling was connected with the radio frequency testing pad 2 (RFTest Pad) of bottom surface with the shortest branch to bottom.That is to say that radio frequency has been divided into two paths after capacitor C 1: the application main road to the module antenna mouth is an ANT pad 1; And be RF testing weld pad 2 to the test branch road of radio frequency testing point.Fig. 3 illustrates ANT pad and the RF testing weld pad position in the printed circuit board (PCB) bottom surface respectively.

When wireless module was produced, the RF testing weld pad was used for the calibration and the test of wireless module radio-frequency (RF) index, and the ANT pad of this moment is in open-circuit condition.When the wireless module practical application, the ANT pad is used for being electrically connected of radio-frequency path between wireless module and its motherboard, finally realizes wireless reception and emission by antenna, and the RF testing weld pad of this moment is in open-circuit condition.Although when placement-and-routing, can be with the test branch road RF testing weld pad control the weak point of trying one's best, this " open circuit " still can be to the certain influence of radio-frequency (RF) index (the especially index of transmitter) generation in another path.And frequency is high more, and this effect is big more.

The more important thing is, above-mentioned influence can't reflect when test, because (use test branch road RF testing weld pad during the wireless module production test, using main road is that the ANT pad is in open-circuit condition) (use application main road ANT pad in the load of PA output pin performance during with the wireless module practical application, the test branch road is that the RF testing weld pad is in open-circuit condition) different in the load meeting of PA output pin performance, thereby cause radio-frequency (RF) index (the especially index of transmitter) to occur deviation in both cases, test can not coincide with application.

The utility model content

Technical problem to be solved in the utility model provides a kind of wireless module based on the LCC encapsulation, its radio frequency testing branch road and practical application main road coincide, thus the radio-frequency (RF) index the when radio-frequency (RF) index when reaching the module practical application is equal to the module production test substantially.

The utility model is that to solve the problems of the technologies described above the technical scheme that adopts be to propose a kind of wireless module based on the LCC encapsulation, comprises an antenna opening pad and a radio frequency testing pad, and wherein, this antenna opening pad overlaps with the position of this radio frequency testing pad.

In embodiment of the present utility model, this wireless module can be made by multilayer board.Wherein, the radio frequency testing pad is the bottom that is positioned at this multilayer board, and the antenna opening pad is that the top layer from multilayer board leads to bottom downwards, and overlaps with the radio frequency testing pad at the bottom place.

The utility model coincides radio frequency testing branch road and practical application main road owing to adopt above technical scheme, thus the radio-frequency (RF) index the when radio-frequency (RF) index when reaching the module practical application is equal to the module production test substantially.

Description of drawings

For above-mentioned purpose of the present utility model, feature and advantage can be become apparent, below in conjunction with accompanying drawing embodiment of the present utility model is elaborated, wherein:

Fig. 1 illustrates the circuit theory diagrams of the radio-frequency antenna mouth of wireless module.

Fig. 2 A-2C illustrates the known PCB structure that realizes circuit shown in Figure 1.

Fig. 3 illustrates the antenna opening pad and the relative position of testing weld pad on the bottom surface of known PCB structure.

Fig. 4 A-4C illustrates the PCB structure of the wireless module of the utility model one embodiment.

Fig. 5 illustrates the sectional structure of the PCB structure of Fig. 4 C at the pad place.

Fig. 6 illustrates the antenna opening pad and the relative position of testing weld pad on the bottom surface of the PCB structure of Fig. 4 C.

Fig. 7 illustrates the test connector of wireless module of the present utility model.

Embodiment

Embodiment of the present utility model adjusts the radio frequency testing point placement location of the wireless module of LCC encapsulation, tests inconsistent with application indexes with reducing of trying one's best.In the following embodiments, still design the PCB structure of wireless module, but under spirit of the present utility model, those skilled in the art can carry out local adjustment on this circuit diagram basis with circuit theory diagrams shown in Figure 1.

Fig. 4 A-4C illustrates the PCB structure of the wireless module of the utility model one embodiment, and wherein Fig. 4 A illustrates the top layer layout of multi-layer PCB separately, and Fig. 4 B illustrates the bottom layout of multi-layer PCB separately, and Fig. 4 C illustrates the layout stacking chart of top layer and the bottom of PCB.At first compare with reference to Fig. 4 A and with Fig. 2 A, the radio frequency input/output terminal of top layer (RF IN/OUT) is through after inductance L 2, capacitor C 1 and the inductance L 1, be connected to the pad sidewall of the stamp hole shape of hole wall that is positioned at the pcb board edge, this promptly is antenna opening pad 11 (an ANT pad).Different with Fig. 2 A is, in Fig. 4 A, radio frequency is not divided into two paths after capacitor C 1, and promptly PCB does not just punch cabling to bottom after inductance L 1 and capacitor C 1.On the contrary, with reference to PCB structure shown in Figure 5 sectional structure at the pad place, the antenna opening pad 11 of present embodiment leads to bottom B downwards from the top layer A of pcb board.On the other hand, shown in Fig. 4 B, radio frequency testing pad 12 is arranged on the bottom of pcb board, and is positioned at the position of antenna opening pad 11.After antenna opening pad 11 leads to bottom, can overlap with radio frequency testing pad 12.Fig. 6 further illustrates antenna opening pad and the RF testing weld pad position in the printed circuit board (PCB) bottom surface.

Thereby will be transmitted to bottom from the radio frequency ANT signal that antenna opening pad top layer is introduced, give the bottom and the radio frequency testing pad of antenna opening pad shared.From equivalent electric circuit, antenna opening pad and radio frequency testing pad are along the same metal interconnected common node N that is electrically connected to.

Based on above-mentioned wireless module structure, by anchor clamps the internal and external conductor of test connector mm126036 shown in Figure 7 is located with the GND signal mutually with the ANT signal of radio frequency testing pad respectively and to contact, can realize the calibration and the test of wireless module radio-frequency (RF) index.

Like this, realized the test branch road of wireless module and used main road uniting two into one, as long as 50 ohm line impedance Control on the motherboard get relatively good, radio-frequency (RF) index when the radio-frequency (RF) index during the module practical application has been equal to the module production test substantially, thus the inconsistent problem of radio-frequency (RF) index when testing and using can be eliminated.

Though the utility model discloses as above with preferred embodiment; right its is not in order to limit the utility model; any those skilled in the art; in not breaking away from spirit and scope of the present utility model; when doing a little modification and perfect, therefore protection range of the present utility model is worked as with being as the criterion that claims were defined.

Claims

1. the wireless module based on the LCC encapsulation comprises an antenna opening pad and a radio frequency testing pad, it is characterized in that this antenna opening pad overlaps with the position of this radio frequency testing pad.

2. the wireless module based on the LCC encapsulation as claimed in claim 1 is characterized in that this wireless module is to be made by multilayer board.

3. the wireless module based on the LCC encapsulation as claimed in claim 2 is characterized in that this radio frequency testing pad is the bottom that is positioned at this multilayer board.

4. the wireless module based on LCC encapsulation as claimed in claim 3 is characterized in that, this antenna opening pad is that the top layer from this multilayer board leads to bottom downwards, and overlaps with this radio frequency testing pad at the bottom place.

5. the wireless module based on the LCC encapsulation as claimed in claim 1 is characterized in that this antenna opening pad and this radio frequency testing pad are electrically connected to a common node, and this common node is couple to a radio frequency input/output terminal by electric capacity.